Psychosocial Functioning , Personality , and Body Image Following Vertical Banded Gastroplasty Background In addition to increased risks of morbidity and mortality , extreme obesity is substantially associated with psychosocial problems . Therefore , the ultimate goal of bariatric surgery should not only be reducing weight and counteracting comorbid conditions but also improving psychosocial functioning . In addition to being an important goal of bariatric surgery , enhanced psychosocial functioning may motivate patients to adhere to adequate health behavior to maintain the surgically established weight loss . Introduction Obesity is a major public health concern . Its prevalence is increasing globally -LSB- 1 -RSB- . In addition to an increased risk of morbidity and mortality caused by medical conditions -LSB- 2 -RSB- , extreme obesity is associated with debilitating psychological and social consequences especially in patients seeking surgery -LSB- 3 -- 6 -RSB- . Psychological consequences of extreme obesity are , among others , anxiety , depression , low self-esteem , and negative body image -LSB- 5 -- 10 -RSB- . Socially , the extremely obese have to deal with prejudice , discrimination , and social isolation -LSB- 11 -RSB- . Because only surgical treatment results in long-term weight reduction and the improvement or cure of comorbidities , including reduction of psychopathology -LSB- 3 -- 6 -RSB- , the number of procedures performed has more than doubled within a few years -LSB- 12 -RSB- . However , studies show great variation in outcome . In contrast to research showing large and long-lasting improvements , other studies suggest that postoperative improvements lag behind functioning of normative groups or show a decline over the years -LSB- 4 , 5 -RSB- . Enhanced psychosocial functioning is an important goal of bariatric surgery . It may motivate patients to adhere to adequate health behavior to maintain the surgically established weight loss -LSB- 13 -RSB- . In addition to medical -- somatic and surgical -- technical factors , success of bariatric surgery is especially influenced by the extent of successful adjustment of eating patterns , which , for a substantial part , can be attributed to psychological factors . Therefore , success after bariatric surgery should not only reflect weight loss and improvement or cure of comorbid conditions but also improvements in eating behavior , psychosocial variables , and quality of life -LSB- 14 -RSB- . However , in contrast to physical changes , psychosocial changes are not studied as systematically or diligently yet -LSB- 15 -RSB- . To facilitate the identification of the psychological variables that are related to success and the development of treatment interventions to enhance adjustment and success , a better understanding of patients ' psychosocial functioning after bariatric surgery is needed . Materials and Methods The present study was designed to increase our understanding of patients ' changes in psychosocial functioning , personality , and body image during the first 2 years after vertical banded gastroplasty -LRB- VBG -RRB- . The main research questions were : what specific improvements can be achieved , is postoperative functioning noticeable different from functioning in relevant normative groups , and do all patients profit ? These questions were examined based on data collection preoperatively and 6 , 12 , and 24 months after VBG . Procedures The restrictive operation technique used in our hospital is hand-assisted laparoscopic vertical banded gastroplasty , with a complete division between the vertical staple lines . VBG is a relative simple , safe , and cost-effective intervention with fewer side effects than other procedures -LSB- 16 -RSB- . Not withstanding this , mixed long-term results , such as weight regain and dietary problems , have been reported -LSB- 17 -RSB- . Contrary to the situation in the USA , in The Netherlands , the numbers of VBGs that have been performed in the last 5 years is rather stable , despite the fact that the number of adjustable gastric banding procedures is showing an enormous increase . Materials Earlier studies of psychosocial factors in the surgical treatment of extreme obesity have not provided consistent findings , which may , in part , be caused by the employment of a wide variety of non-standardized assessment procedures of questionable reliability and validity -LSB- 11 -RSB- . In the present study , we assessed preoperative as well as postoperative psychosocial functioning , personality , and body image using a semi-structured interview and three standardized questionnaires . As interview-based psychological studies may be questionable , we will report here only on the questionnaire data . Preoperatively as well as on three follow-up assessment points , patients filled in the Symptom Checklist-90 -LRB- SCL-90 -RRB- -LSB- 18 -RSB- , the Dutch Personality Questionnaire -LRB- NVP -RRB- -LSB- 19 -RSB- , and the Body Attitude Test -LRB- BAT -RRB- -LSB- 20 -RSB- . The SCL-90 is a multidimensional psychopathology indicator with eight subscales and one summarized score -LRB- psychoneuroticism -RRB- ; its psychometric qualities are satisfactory to good -LSB- 21 -RSB- . In addition to neuroticism , the NPV measures six personality characteristics ; its psychometric qualities are also satisfactory to good -LSB- 22 -RSB- . The BAT measures subjective body experience and the attitude towards one 's own body ; it has three subscales and one summarized total score , is commonly used in Europe , and is a reliable and valid questionnaire -LSB- 20 -RSB- . Patients In the context of standard preoperative evaluation , 131 patients who underwent VBG in our hospital between January 2001 and October 2004 were psychologically assessed . In addition to the inclusion criteria determined by IFSO -LSB- 23 -RSB- , we required 10 % preoperative weight loss with a minimum of 12 kg . From these 131 patients , 104 -LRB- 79.4 % -RRB- could be included in our study ; others did not respond to our repeated requests for follow-up or sending back questionnaires . The studied patient group consisted of 91 -LRB- 87.5 % -RRB- female and 13 -LRB- 12.5 % -RRB- male patients . Preoperatively , they had a mean age of 38.4 ± 8.3 years , an average body mass index -LRB- BMI -RRB- of 45.4 ± 5.1 , and a mean percentage excess weight of 104.5 ± 22.1 % . Statistical Analyses Statistical analyses were performed using the SPSS 14.0-packet -LRB- SPSS for Windows , Rel . 14.0 . 2005 , SPSS Inc. , Chicago -RRB- . To study changes over time in weight , psychosocial functioning , personality , and body image , mixed between-within subjects analyses of variance for repeated measures were performed -LRB- ANOVA ; time as within-subjects factor , gender as between-subjects factor -RRB- . To identify waning of changes , Bonferroni post hoc equations were used . To compare patients ' questionnaire scores to normative data , we used one-sample t tests . To identify heterogeneity in postoperative psychosocial functioning , descriptive statistics were used using summarized scales whenever possible for reasons of clarity . In reporting excess weight -LRB- EW -RRB- and excess weight loss -LRB- EWL -RRB- , we followed the guidelines of Deitel and Greenstein -LSB- 24 -RSB- . Results Weight Loss Over time , using ANOVA , substantial and significant changes in mean BMI , EW , and EWL were found . From preoperative status to 2 years after surgery , BMI and EW significantly -LRB- P ≤ 0.001 -RRB- decreased 13.5 points and 58.6 % , respectively , which represent a large size -LRB- partial η2 = 0.83 -RRB- -LSB- 25 -RSB- . After 2 years , using the criterion that an operation can be conceived of as successful when EWL ≥ 50 % -LSB- 26 -RSB- , 61 % of the patients had a successful operation . Preoperatively , 91.3 % of the patients were extremely obese ; in contrast , 2 years after surgery , only 12 % was extremely obese . Psychosocial Functioning Our earlier literature review suggests that psychopathology is related to extreme obesity , manifesting itself mostly as depression or anxiety -LSB- 11 -RSB- . In assessing psychosocial functioning , we used the SCL-90 to assess short-term psychosocial functioning -LSB- 18 -RSB- and the NPV neuroticism scale to measure long-term neuroticism -LSB- 19 -RSB- . With respect to all aspects , except for hostility , significant changes over time were found -LRB- for most of the comparisons , P ≤ 0.001 ; for neuroticism , P ≤ 0.01 ; for sleeping problems , P ≤ 0.05 -RRB- . For the majority of alterations , large effect sizes were found -LSB- 25 -RSB- . Post hoc analyses showed that compared to the preoperative status , for most aspects of psychosocial functioning , scores were significantly lower on all follow-up assessment points , reflecting better psychosocial functioning . However , depressive symptoms and neuroticism were only significantly lower 6 months and 1 year after surgery ; sleeping problems were lower only 6 months after surgery . For most aspects of psychosocial functioning , there was only a significant decrease in scores from preoperative status to 6 months postoperatively , however , not between 6 months and 1 year or between 1 and 2 years postoperatively -LRB- Table 1 -RRB- . Table 1Postoperative changes in psychosocial functioning -LRB- mean ± SD -RRB- SCL-90Preoperative6 months1 year2 yearsPartial η2Anxiety14 .3 ± 5.011.7 ± 2.4 *** 12.1 ± 3.912.6 ± 5.6.23 Phobic complaints9 .3 ± 3.67.4 ± 1.1 *** 7.5 ± 1.67.9 ± 3.1.20 Depression24 .8 ± 8.620.8 ± 6.3 *** 20.9 ± 7.123.1 ± 11.3.18 Somatic complaints21 .2 ± 7.916.2 ± 3.5 *** 17.0 ± 5.217.9 ± 6.7.29 Obsessive15 .0 ± 5.011.6 ± 2.7 *** 12.0 ± 3.112.7 ± 5.1.28 Sensitivity28 .7 ± 10.423.0 ± 6.4 *** 22.8 ± 6.124.2 ± 10.8.25 Hostility7 .3 ± 1.77.2 ± 2.07.1 ± 1.57.3 ± 2.4.06 Sleeping problems5 .7 ± 2.94.6 ± 2.3 * 4.9 ± 2.55.5 ± 3.1.09 Psychoneuroticism139 .5 ± 41.0113.0 ± 22.7 *** 114.8 ± 26.4122.8 ± 45.2.30 N93939393Neuroticism -LRB- NPV -RRB- 11.98 ± 8.98.5 ± 7.4 ** 8.0 ± 6.69.3 ± 8.8.15 N94949494Because of listwise exclusion , n = 93 -LRB- SCL-90 -RRB- or 94 -LRB- NPV -RRB- on all moments ; Obsessive : obsessive compulsive behavior ; Sensitivity : mistrust and interpersonal sensitivity . *** P < 0.001 ** P < 0.01 * P < 0.05 Furthermore , we compared patients ' mean scores on psychosocial functioning to corresponding scores obtained in relevant normative groups , reflecting the general population -LSB- 18 , 19 -RSB- . Compared to those normative groups , mean preoperative scores for psychosocial functioning were significantly higher , except for hostility . However , with respect to preoperative neuroticism , no significant difference was found . Postoperatively , there was a mixed picture . In spite of these inconsistencies , the overall picture revealed that on most subscales and most follow-up assessment points , patients ' mean scores were not significantly different from the corresponding scores obtained in the normative groups . Two years after surgery , patients ' mean scores on measures of sleeping problems and somatic complaints were again significantly higher than the normative group 's scores . As to neuroticism , patients ' postoperative mean scores were significantly lower than the normative group 's scores on all follow-up assessment points . Despite these differences , all postoperative patients ' scores fell in the below mean , mean , or above mean categories of the normative groups ' scores . Personality Because personality substantially influences health behavior , personality characteristics may be relevant for adjustment to surgery -LSB- 27 -RSB- . According to earlier literature reviews , extremely obese individuals can be described as , among others , immature persons having a poor impulse control and a low self-esteem -LSB- 28 -RSB- . With respect to postoperative personality change , mixed results have been reported . For instance , some studies suggest that patients still have more pathology than comparison groups -LSB- 13 -RSB- , whereas other research suggests that personality remains largely unchanged -LSB- 3 -RSB- . In assessing personality with the NPV -LSB- 19 -RSB- , over time , we only found , with a large effect size -LSB- 25 -RSB- , a significant -LRB- P ≤ 0.01 -RRB- change in self-esteem . Post hoc analyses revealed that compared to the preoperative status , self-esteem was significantly higher 1 year postoperatively . Six months after surgery , there was a tendency to significance -LRB- P = 0.06 -RRB- . Two years postoperatively , however , no significant difference was found . Also , no significant differences were found between follow-up assessment points -LRB- Table 2 -RRB- . Table 2Postoperative changes in personality characteristics -LRB- mean ± SD -RRB- NPV subscalesPreoperative6 months1 year2 yearsPartial η2Social anxiety8 .9 ± 7.96.8 ± 6.57.0 ± 6.57.5 ± 7.1.0.07 Rigidity24 .4 ± 7.324.0 ± 7.924.2 ± 7.423.7 ± 7.80.03 Hostility14 .0 ± 8.514.1 ± 8.614.0 ± 8.915.3 ± 9.30.05 . Egoism9 .7 ± 4.710.6 ± 5.19.9 ± 4.810.4 ± 5.00.04 Dominance13 .9 ± 6.415.3 ± 7.515.3 ± 7.215.0 ± 7.30.06Self-esteem27.9 ± 6.029.7 ± 5.329.9 ± 5.5 * 28.6 ± 6.70.14 N94949494Because of listwise exclusion , n = 94 on all moments . * P < 0.01 We did not find many significant personality changes , but compared to normative data -LSB- 19 -RSB- , we did find some significant differences . Compared to a relevant normative group , reflecting the general population , patients ' mean preoperative scores on social anxiety , dominance , and self-esteem were not significantly different . However , they were after surgery , albeit not on all follow-up assessment points and not always for both sexes . Postoperatively , patients ' scores on social anxiety were lower , whereas their scores on dominance and self-esteem were higher than the corresponding scores obtained in the normative group . On scales of Hostility and Egoism , preoperatively , patients had significant lower mean scores ; postoperatively , this was only the case for some small subgroups . On the Rigidity measure , patients had significantly lower mean scores on all measurement moments preoperatively as well as postoperatively . All patients ' mean scores fell in the below mean , mean , or above mean categories of the normative group 's scores . Body Image Some studies suggest that especially for female patients , the desire to improve their physical appearance and avoidance of embarrassment are the most common motivators for bariatric surgery -LSB- 29 -RSB- . Also , improved body image would be one of the main reasons for post-surgical psychological improvement , better social integration , and enhanced quality of life -LSB- 30 -RSB- . Weight loss after bariatric surgery leads to marked improvements in body image and attractiveness and to less shame . However , with time , some patients still feel overweight , are discontent with the increasing skin folds -LSB- 13 -RSB- , or still may have more concern with their body shape and size than controls -LSB- 31 -RSB- . In our earlier study , we found that preoperatively , patients reported significantly higher body dissatisfaction and negative body image than general population samples -LSB- 28 -RSB- . In the present study , using the BAT -LSB- 20 -RSB- , over time , we found significant -LRB- P ≤ 0.001 -RRB- changes in negative appreciation of body size , lack of familiarity with one 's own body , general body dissatisfaction , and the summarized BAT score , reflecting improved body image and large effect sizes -LSB- 25 -RSB- . Post hoc analyses showed that compared to the preoperative status , scores were significantly -LRB- P ≤ 0.001 -RRB- lower on all three follow-up assessment points . We found significant decreases between preoperative status and 6 months postoperatively , however , not between 6 months and 1 year or between 1 and 2 years after surgery -LRB- Table 3 -RRB- . Also , in contrast to the preoperative situation , on all three follow-up assessment points , body image was significantly correlated to BMI , reflecting a more positive body image when BMI was lower -LRB- r varied from 0.37 , 6 months postoperatively , to 0.29 , 1 year postoperatively , and 0.31 , 2 years after surgery -RRB- . Table 3Postoperative changes in body image -LRB- mean ± SD -RRB- Preoperative6 months1 year2 yearsPartial η2Negative appreciation of body size26 .2 ± 5.814.9 ± 7.1 * 14.4 ± 8.214.2 ± 8.20.59 Lack of familiarity with one 's own body16 .5 ± 7.27.5 ± 4.7 * 7.1 ± 4.87.5 ± 6.10.52 General body dissatisfaction15 .2 ± 3.68.1 ± 4.6 * 8.0 ± 4.68.3 ± 5.00.61 Total BAT score64 .0 ± 15.436.9 ± 15.6 * 35.8 ± 16.235.9 ± 17.40.63 N97979797Because of listwise exclusion , n = 97 on all moments . * P < 0.001 Although we found significant improvements in body image over time , on all moments , preoperatively as well as postoperatively , and on all scales , patients ' mean scores were significantly -LRB- P ≤ 0.001 or P ≤ 0.01 -RRB- higher than those of -LRB- female students -RRB- normative groups -LSB- 20 , 32 -RSB- . Heterogeneity in Postoperative Psychosocial Functioning Most studies report broad psychosocial improvements after bariatric surgery . However , a significant minority of extremely obese patients do not benefit from surgery -LSB- 4 -RSB- . Some patients may even have difficulties in adapting psychosocially to the various consequences of bariatric surgery -LSB- 13 -RSB- . In the present study , in addition to a large variation in EWL , we found substantial variance with respect to changes in psychosocial functioning . Especially with respect to psychoneuroticism and neuroticism , most patients reported postoperative improvements ; however , this was not the case for all patients . For instance , in the case of psychoneuroticism , 77 out of 99 patients -LRB- 77.8 % -RRB- reported improvement after 6 months ; in contrast , 21 patients -LRB- 21.2 % -RRB- had higher scores , and one patient did not change . After 24 months , approximately two thirds of the patient group -LRB- 64.7 % -RRB- still had better scores on psychoneuroticism , whereas one third -LRB- 31.4 % -RRB- showed signs of an increase in psychoneuroticism . In the case of personality characteristics , a mixed picture was found ; however , in general , there were only small differences between patients reporting positive or negative changes . Regarding body image , almost all patients reported improvements , and these were quite stable over time . Discussion After vertical banded gastroplasty , in addition to substantial and significant weight loss , patients also changed for the better in body image and most domains of psychosocial functioning . With respect to personality , only a significant improvement in self-esteem was found . Unfortunately , there was substantial variance in improvements , and some improvements waned over time . Most of our findings are in line with other studies , with respect to weight loss -LSB- 33 -RSB- , as well as regarding improvements in psychosocial functioning and body image -LSB- 7 , 8 -RSB- . The fact that we could not demonstrate many significant changes in patients ' personality is in contrast to the results of some studies -LSB- 34 -RSB- , but is consistent with the suggestion that there is no obese personality -LSB- 35 -RSB- ; furthermore , because of the stability of personality , these findings might be expected . The impact of bariatric surgery seems to be more in the areas of symptoms of psychopathology . Just like others , we found a decline of some psychosocial improvements over the years -LSB- 13 -RSB- . Various explanations have been suggested for waning psychosocial improvements , for example , stabilization or rising of patients ' weight , disappointment that life did not improve dramatically after substantial loss of weight , or difficulties in adapting psychologically to the consequences of bariatric surgery -LSB- 13 -RSB- . Also , our results concerning patients ' postoperative heterogeneity are in accordance with earlier findings -LSB- 36 -RSB- . These outcomes underscore the suggestion that vertical banded gastroplasty , just like other methods of bariatric surgery , is not equally effective for each patient . Although our study has some assets , such as the employment of standardized , reliable questionnaires and the focus on psychosocial functioning in a wide variety of domains of life , some weaker points could also be indicated . For instance , we were not able to retain all patients of our preoperative sample . This problem is also identified by others who suggest that patients ' participation in psychological follow-up is much lower than in follow-up visits for other specialists of the bariatric team -LSB- 37 -RSB- . Although we found mixed results , the overall psychosocial improvements provide additional justification for vertical banded gastroplasty as a surgical treatment option for extreme obesity . However , as some improvements wane over time and not all patients profit in the same way , surgery alone may not be sufficient to sustain success . Consequently , additional behavioral treatment may be necessary .

B I O B O O B I O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O B I O O O O O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O B I O O O O O O O O O O O O O O O O O O O O B I O B O O B I O O O O O O B I I O O O O O O O O O O O O O O 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Ambulatory blood pressure monitoring and renal functions in children with a solitary kidney The aim of this study is to investigate the blood pressure -LRB- BP -RRB- profile , microalbuminuria , renal functions , and relations with remaining normal kidney size in children with unilateral functioning solitary kidney -LRB- UFSK -RRB- . Sixty-six children with UFSK were equally divided into three groups : unilateral renal agenesis -LRB- URA -RRB- , unilateral atrophic kidney -LRB- UAK -RRB- , and unilateral nephrectomy -LRB- UNP -RRB- . Twenty-two age - , weight - , and height-matched healthy children were considered as a control group . The serum creatinine level and first-morning urine microalbumin and creatinine concentrations were determined by the standard methods . Also , the BP profile was determined by ambulatory blood pressure monitoring -LRB- ABPM -RRB- . We found that the serum creatinine level was higher and creatinine clearance was lower in each patient groups compared to those of the control group -LRB- p < 0.05 -RRB- . Compared with the controls , each group of patients had mean office , 24-h , daytime , and night-time systolic and diastolic BP values similar to those of the controls -LRB- p > 0.05 -RRB- . An inverse correlation was found between the renal size standard deviation scores -LRB- SDS -RRB- of normal kidneys and 24-h systolic and diastolic BP load SDS in all of the patients -LRB- p < 0.05 ; r = − 0.372 , r = − 0.295 , respectively -RRB- . The observed relationship between renal size SDS and 24-h mean arterial pressure -LRB- MAP -RRB- , systolic and diastolic BP load SDS suggests that children with UFSK should be evaluated by using ABPM for the risk of hypertension . Introduction Arterial hypertension , proteinuria , and impaired renal functions are potential complications of unilateral functioning solitary kidney -LRB- UFSK -RRB- , including unilateral renal agenesis -LRB- URA -RRB- , unilateral atrophic kidney -LRB- UAK -RRB- , and unilateral nephrectomy -LRB- UNP -RRB- . The reduction of renal mass leads to compensatory hypertrophy of the remaining renal tissue in these patients -LSB- 1 -- 3 -RSB- . Functionally , the remnant kidney will partly compensate for the lost function by increasing its workload , which is accompanied by increased glomerular blood flow and blood pressure -LRB- BP -RRB- , so-called hyperfiltration -LSB- 4 -RSB- . It has been shown in animal models of unilateral renal ablation that the remaining kidney undergoes accelerated structural renal damage , generally in the form of glomerulosclerosis , with varying degrees of renal insufficiency , partly amenable to a variety of therapeutic interventions -LSB- 5 , 6 -RSB- . A relatively small number of long-term follow-up studies in humans has documented that the surgical loss of renal functional mass in the presence of a normal remnant kidney rarely leads to renal insufficiency , although the incidence of mild to moderate proteinuria and hypertension has increased -LSB- 7 -- 10 -RSB- . Kasiske et al. -LSB- 11 -RSB- reported that UNP does not cause progressive renal dysfunction , but it may be associated with a small increase in BP . On the other hand , Wikstad et al. -LSB- 8 -RSB- showed that adults born with URA or UNP in childhood did not have a marked increase in arterial BP or renal insufficiency . Some reports , however , indicate that patients with URA or with an UFSK left after nephrectomy may have proteinuria and focal glomerular sclerosis -LSB- 5 , 12 -RSB- . Janda et al. -LSB- 13 -RSB- recorded marginal diastolic hypertension in one third of their subjects in a study of 40 children and/or adolescents -LRB- 23 URA , 17 UNP -RRB- . Although some investigators have reported an increase in the prevalence of hypertension and/or proteinuria , others have failed to document these abnormalities -LSB- 11 -RSB- . The discrepancy among the results of these studies may be caused due to a difference in the amount of renal mass removed , the age at the time of renal mass reduction , or unsuspected damage in the remaining kidney . In the past few years , ABPM has become an accepted method for investigating the BP profile in children with renal disorders -LSB- 14 -- 16 -RSB- . Over the years , ambulatory blood pressure monitoring -LRB- ABPM -RRB- has been increasingly used to investigate hypertension in different pediatric populations -LSB- 17 -- 20 -RSB- . A careful review of the literature shows that there are few reports on ABPM , microalbuminuria , and renal functions in children with UFSK -LSB- 21 -RSB- . Furthermore , the utility of BP in children with UFSK is not well established . Therefore , the aim of this study was to investigate the BP profile by ABPM , microalbuminuria , renal functions , and relations with remaining normal kidney size in children with UFSK . Materials and methods Sixty-six children with a mean age of 8.32 ± 4.23 and range 0.5 and 18 years with UFSK were equally divided into three groups : URA group -LRB- n = 22 -RRB- , UAK group -LRB- n = 22 -RRB- , and UNP group -LRB- n = 22 -RRB- . Twenty-two Age - , weight - , and height-matched healthy children were considered as a control group -LRB- Table 1 -RRB- . Renal ultrasound was normal in all controls . Informed consent was obtained from the children and their parents prior to the testing , and the study was approved by the local ethics committee of the School of Medicine , Çukurova University , Adana , Turkey . Table 1Demographic data , anthropometric data , and renal functional parameters of the patients and control groupsParametersURA -LRB- n = 22 -RRB- UAK -LRB- n = 22 -RRB- UNP -LRB- n = 22 -RRB- Controls -LRB- n = 22 -RRB- Gender -LRB- M/F -RRB- 11/1112/1010 / 1210/12Age -LRB- years -RRB- 8.63 ± 4.508.03 ± 4.308.31 ± 4.048.78 ± 3.49 Weight -LRB- kg -RRB- 28.44 ± 18.0727.01 ± 17.1426.57 ± 10.4829.19 ± 10.92 Height -LRB- cm -RRB- 124.55 ± 27.62126.05 ± 25.22123.96 ± 21.21128.36 ± 26.44 BMI -LRB- kg/m2 -RRB- 16.60 ± 2.9517.96 ± 3.1416.77 ± 2.0516.96 ± 1.91 UMA -LRB- mg/L -RRB- 5.46 ± 3.914.80 ± 2.034.56 ± 8.115.18 ± 4.09 UMA/UCr -LRB- mg/mg -RRB- 0.23 ± 0.720.17 ± 0.300.07 ± 0.130.06 ± 0.06 GFR -LRB- ml/dk/1 .73 m2 -RRB- 1121.95 ± 34.19123.66 ± 43.67108.57 ± 26.71155.85 ± 41.27 Serum Cr -LRB- mg/dl -RRB- 20.59 ± 0.130.60 ± 0.150.65 ± 0.100.47 ± 0.13 Renal size -LRB- mm -RRB- 100.32 ± 18.4291.32 ± 17.5697.23 ± 17.4992.36 ± 16.00 Values are expressed as mean ± SD , M : male , F : female , BMI : body mass index , UMA : urine microalbumin , UCr : urine creatinine , GFR : glomerular filtration rate1p < 0.05 URA vs. controls , UAK vs. controls , and UNP vs. controls2p < 0.05 URA vs. controls , UAK vs. controls , and UNP vs. controls Both renal agenesis and atrophic kidney were established through renal ultrasound and scintigraphy . A non-functioning kidney is caused due to unilateral vesicoureteral reflux -LRB- in seven cases -RRB- , ureteropelvic junction obstruction -LRB- in 10 cases -RRB- , and multicystic dysplastic kidney -LRB- in five cases -RRB- in the UAK group . In contrast , indications for nephrectomy contained unilateral Wilms ' tumor -LRB- in six cases -RRB- , a non-functioning kidney is caused due to unilateral vesicoureteral reflux -LRB- in 10 cases -RRB- and ureteropelvic junction stenosis -LRB- in two cases -RRB- , multicystic dysplastic kidney -LRB- in two cases -RRB- , and nephrolithiasis -LRB- in two cases -RRB- in the UNP group . Patients with Wilms ' tumor have favorable type and they did not receive chemotherapy . The mean time due to nephrectomy was 4.06 ± 3.87 years -LRB- range 0.5 -- 17 years -RRB- in this group . All patients had a normal renal function defined as a glomerular filtration rate -LRB- GFR -RRB- of over 90 ml/min 1.73 m2 -LRB- as determined by Schwartz et al. 's formula -LSB- 22 -RSB- -RRB- and normal urinary sediment . The remaining kidney has findings of normal ultrasound and normal scintigraphy in all patient groups . Only children without any anatomical abnormalities of the remaining kidney and with normal GFR were included in the study . No patient was treated with antihypertensive drugs or drugs interfering with BP . Neither the study patients nor children in the control groups had a positive -LRB- first-degree-relative -RRB- family history of hypertension . Patients with a renal scar in their solitary kidney or who have other urinary tract anomaly were withdrawn from the study . In all of the study group participants , urinalysis , serum uric acid , creatinine , cholesterol , protein and albumin levels , and first-morning urine microalbumin and creatinine concentrations were determined by the standard methods . In all subjects , ABPM was performed over 24 h using the SpaceLabs 90217 oscillometric device -LRB- Redmond , Washington -RRB- . The appropriately sized cuff , chosen based on arm width , was placed on the non-dominant arm . The BP was automatically recorded in every 15 min during the day and every 30 min at night . Only ABPM profiles with at least 30 recordings , including at least eight readings between midnight and 06.00 h , were accepted . Daytime was defined as 08.00 -- 20.00 h and night-time as 00.00 -- 06.00 h , according to the study of Soergel et al. -LSB- 23 -RSB- . For each subject , the BP values corresponding to the 95th percentile , according to sex and height , was determined -LSB- 23 , 24 -RSB- . Hypertension was defined as a systolic BP and/or diastolic BP > 95th percentile . The percentage of systolic BP and diastolic BP readings above this value constituted a measurement of 24-h systolic and diastolic BP load , respectively . The dipping status was calculated by subtracting the mean night-time BP from the mean daytime BP , and then dividing this value by the mean daytime BP . Dipping was defined as a ≥ 10 % drop in mean systolic BP or diastolic BP between daytime and night-time . Renal size and BP standard deviation scores -LRB- SDS -RRB- was calculated according the left main stem -LRB- LMS -RRB- method -LSB- 24 , 25 -RSB- . The renal size of the normal kidney was evaluated by performing abdominal ultrasound and measuring the lower-to-upper-pole length in the supine longitudinal view by the same observer . Renal size SDS values were correlated to the BP SDS values for each patient . Renal size percentiles were determined and evaluated according to standard length-against-height-nomogram defined by Dinkel et al. -LSB- 26 -RSB- . Compensatory hypertrophy was accepted when the measured renal size was found to be greater than the 95th percentile , and its effect on the BP parameters was evaluated . All data were stored and analyzed using the SPSS statistical package -LRB- SPSS Inc. , Chicago , Illinois -RRB- . The normality Kolmogorov-Smirnov test was performed to determine whether continuous variables were normally distributed or not . Differences between groups were analyzed using the non-parametric Kruskal-Wallis test and the Mann-Whitney U test . All values are expressed as mean ± SD . The prevalence of hypertension was determined using Fisher 's exact test . The relationships between variables were analyzed with the non-parametric Spearman 's correlation test in each group . A value of p < 0.05 was considered to be statistically significant . Results The demographic data and renal function parameters of all of the study groups and controls are shown in Table 1 . Age , height , weight , BMI , urine microalbumin , urine microalbumin to urine creatinine ratio , and renal size values are not different between each patient group and the controls -LRB- p > 0.05 -RRB- . The mean serum creatinine level was higher in all patient groups compared to that of the control group -LRB- p = 0.006 between URA and control , p = 0.004 between UAK and control , p < 0.001 between UNP and control -RRB- and the GFR was lower in all patient groups compared to that of the control group -LRB- p = 0.005 between URA and control , p = 0.016 between UAK and control , p < 0.001 between UNP and control -RRB- . Mean heart rates -LRB- 24 h , daytime , night-time -RRB- , mean systolic and diastolic BP parameters -LRB- office BP , 24 h , daytime , night-time -RRB- , mean systolic and diastolic BP dipping , and 24-h systolic and diastolic BP loads are all given in Table 2 . When compared to the controls , each group with UFSK had mean office , 24-h , daytime , and night-time systolic and diastolic BP , and heart rate values similar to those of the controls -LRB- p > 0.05 -RRB- . Only the mean 24-h diastolic BP was higher in the URA group than that of the control group -LRB- p = 0.039 -RRB- . In addition , the diastolic load was higher in the UAK group than that of the control group -LRB- p = 0.012 -RRB- . There was no significant difference in the mean office , 24-h , daytime , and night-time systolic and diastolic BP , and heart rate between all of the patient groups -LRB- p > 0.05 -RRB- . The mean office systolic and diastolic BP , respectively , were higher than the mean daytime systolic and diastolic BP in all groups . The prevalence of hypertension in the URA group was 23 % -LRB- 5/22 -RRB- , in the UAK group was 23 % -LRB- 5/22 -RRB- , in the UNP group was 32 % -LRB- 7/22 -RRB- -LSB- in all patients , it was 26 % -LRB- 17/66 -RRB- -RSB- , and in the controls it was 5 % -LRB- 1/22 -RRB- . The prevalence of hypertension in patients was higher compared to that in the controls -LRB- p = 0.035 -RRB- . The prevalence of non-dipping phenomenon in the URA group was 23 % -LRB- 5/22 -RRB- , in the UAK group was 36 % -LRB- 8/22 -RRB- , in the UNP group was 32 % -LRB- 7/22 -RRB- -LSB- in all patients , it was 30 % -LRB- 20/66 -RRB- -RSB- , in the controls it was 9 % -LRB- 2/22 -RRB- . There was a statistically significant difference between patients and the controls -LRB- p = 0.049 -RRB- . Table 2Average pulse rate and blood pressure -LRB- BP -RRB- of the patients and the control groupsParametersURA -LRB- n = 22 -RRB- UAK -LRB- n = 22 -RRB- UNP -LRB- n = 22 -RRB- Controls -LRB- n = 22 -RRB- Av . 24-h HR -LRB- beats/min -RRB- 89.36 ± 15.7994.64 ± 17.7488.18 ± 12.9590.82 ± 14.79 Av . daytime HR -LRB- beats/min -RRB- 92.64 ± 15.5197.14 ± 17.2793.09 ± 12.9697.41 ± 15.55 Av . night-time HR -LRB- beats/min -RRB- 80.23 ± 15.9986.46 ± 18.0177.86 ± 12.4382.50 ± 16.65 Av . office SBP -LRB- mmHg -RRB- 113.96 ± 16.00116.96 ± 11.24114.55 ± 14.83114.68 ± 12.66 Av . office DBP -LRB- mmHg -RRB- 74.73 ± 10.4871.50 ± 11.0671.05 ± 13.0072.00 ± 9.67 Av . 24-h MAP -LRB- mmHg -RRB- 80.00 ± 7.9278.82 ± 7.1678.41 ± 7.0678.27 ± 3.89 Av . 24-h SBP -LRB- mmHg -RRB- 106.64 ± 10.87105.59 ± 9.31104.22 ± 8.04105.05 ± 6.90 Av . 24-h DBP -LRB- mmHg -RRB- 165.91 ± 6.8264.55 ± 6.5964.09 ± 6.8763.41 ± 3.63 Av . daytime MAP -LRB- mmHg -RRB- 81.14 ± 9.1480.00 ± 8.0479.68 ± 7.3380.68 ± 4.86 Av . daytime SBP -LRB- mmHg -RRB- 109.59 ± 11.75107.18 ± 10.01106.55 ± 7.95108.14 ± 6.83 Av . daytime DBP -LRB- mmHg -RRB- 68.36 ± 8.3666.46 ± 7.1766.18 ± 7.2867.41 ± 4.36 Av . night-time MAP -LRB- mmHg -RRB- 72.86 ± 6.5571.86 ± 7.7072.09 ± 6.7673.64 ± 4.99 Av . night-time SBP -LRB- mmHg -RRB- 99.82 ± 9.3699.32 ± 9.9999.00 ± 7.7898.55 ± 6.60 Av . night-time DBP -LRB- mmHg -RRB- 59.00 ± 5.4658.23 ± 7.1858.09 ± 6.7357.59 ± 3.75 Av . SBP dipping -LRB- % -RRB- 8.26 ± 4.297.31 ± 4.686.58 ± 3.428.83 ± 3.74 Av . DBP dipping -LRB- % -RRB- 13.12 ± 6.5412.24 ± 7.6412.03 ± 7.1914.87 ± 6.32 Av . 24-h SBP load -LRB- % -RRB- 19.71 ± 25.7526.31 ± 25.1421.88 ± 20.0814.45 ± 13.81 Av . 24-h DBP load -LRB- % -RRB- 221.22 ± 17.1233.0.2 ± 28.9926.24 ± 24.5613.54 ± 13.75 Values are expressed as mean ± SD , Av. : average , HR : heart rate , MAP : mean arterial pressure , SBP : systolic blood pressure , DBP : diastolic blood pressure1p = 0.039 between URA and control groups2p = 0.012 between UAK and control groups Compensatory hypertrophy -LRB- renal size percentile > 95 % -RRB- was seen in 59 % -LRB- 39/66 -RRB- of patients . Age , height , weight , renal size , and GFR were statistically significantly higher in patients with compensatory hypertrophy than in patients without compensatory hypertrophy . In contrast , the mean heart rates were lower in patients with > 95th percentile of renal size -LRB- Table 3 -RRB- . Table 3Some characteristics of the patients with unilateral functioning solitary kidney -LRB- USFK -RRB- according the percentile of renal sizeParametersRenal size < 95th percentile -LRB- n = 27 -RRB- Renal size > 95th percentile -LRB- n = 39 -RRB- pAge -LRB- year -RRB- 5.91 ± 3.169.99 ± 4.09 < 0.001 Height -LRB- cm -RRB- 113.19 ± 21.24132.92 ± 23.47 < 0.001 Weight -LRB- kg -RRB- 19.80 ± 9.8932.56 ± 16.41 < 0.001 Renal size -LRB- mm -RRB- 80.37 ± 11.13107.31 ± 12.71 < 0.001 GFR -LRB- ml/dk/1 .73 m2 -RRB- 107.82 ± 37.31125.15 ± 33.09 < 0.05 Av . 24-h HR -LRB- beat/min -RRB- 99.19 ± 15.4984.87 ± 12.96 < 0.001 Av . daytime HR -LRB- beat/min -RRB- 102.00 ± 13.8188.95 ± 13.99 < 0.001 Av . night-time HR -LRB- beat/min -RRB- 88.59 ± 17.0576.62 ± 13.02 < 0.05 Values are expressed as mean ± SD , Av. : average , GFR : glomerular filtration rate , HR : heart rate Renal size SDS was correlated with some BP SDS parameters in the patients and the controls . Statistically significant correlations are shown in Table 4 . There was no correlation between the renal size SDS and BP parameters , but an inverse correlation was found between the renal size SDS and 24-h MAP SDS , 24-h systolic and diastolic BP load SDS in all of the patients , but these correlations were not found in the controls . Table 4Correlation between renal size standard deviation scores -LRB- SDS -RRB- and some parameters SDS in patients with UFSK and the controlsGroupsParametersrpPatients -LRB- n = 66 -RRB- Av . 24-h MAP SDS − 0.2840.021 Av . 24-h SBP SDS − 0.1750.159 Av . 24-h DBP SDS − 0.0340.788 Av . 24-h SBP load SDS − 0.3720.002 Av . 24-h DBP load SDS − 0.2950.016 Controls -LRB- n = 22 -RRB- Av . 24-h MAP SDS − 0.0110.962 Av . 24-h SBP SDS − 0.0670.767 Av . 24-h DBP SDS − 0.3120.158 Av . 24-h SBP load SDS − 0.1480.510 Av . 24-h DBP load SDS − 0.0190.934 SDS : standard deviation scores , Av. : average , MAP : mean arterial pressure , SBP : systolic blood pressure , DBP : diastolic blood pressure Discussion The UFSK is usually considerably enlarged , this constituting a compensatory diffuse but not partial , lobar enlargement , usually with a larger than normal pelvis -LSB- 27 -RSB- . The reduction of renal mass in the rat is associated with hyperfiltration and hypertrophy of the remaining nephrons , ultimately resulting in proteinuria , renal failure , and hypertension . Nagata et al. -LSB- 28 -RSB- reported that unilateral nephrectomy in young rats leads to a higher incidence of glomerular sclerosis than is observed in adult rats . A study conducted by Regazzoni et al. -LSB- 29 -RSB- in a follow-up of UNP in children has reported a decreased renal reserve capacity , but detected no evidence of hypertension or proteinuria . In our study , subjects were screened with urine microalbumin , urine and serum creatinine , GFR , and urine microalbumin-to-creatinine ratios in first-morning urine for the detection of proteinuria and renal functions . No statistically significant difference was found between the urine microalbumin and microalbumin-to-creatinine ratios in the first-morning urine in all of the patient and control groups . However , the GFR was lower and the serum creatinine level was higher in the subgroups of patients than those of the control group . These results show that a mild renal dysfunction may be detected in patients with UFSK . Although some investigators have reported an increased prevalence of hypertension , others have failed to document these abnormalities in children with UFSK -LSB- 11 -RSB- . Janda et al. -LSB- 13 -RSB- recorded marginal diastolic hypertension in one third of their subjects in a study of 40 children and/or adolescents -LRB- 23 URA , 17 UNP -RRB- . As we mentioned before , there are few reports which have utilized 24-h ABPM in UFSK children . Mei-Zahav et al. -LSB- 21 -RSB- showed that the presence of an UFSK , from whatever cause , leads to an increase in BP . This is particularly manifested in systolic BP and even more so in daytime systolic BP . Kasiske et al. -LSB- 11 -RSB- reported that UNP does not cause progressive renal dysfunction , but may be associated with a small increase in BP . On the other hand , Wikstad et al. -LSB- 8 -RSB- concluded that adults born with URA or UNP in childhood did not have a marked increase in arterial BP or renal insufficiency . We measured the ABPM in three groups of patient with UFSK and found that they have the same characteristics as in healthy controls . However , in our study , the mean office , 24-h systolic , daytime , and night-time systolic and diastolic BP , mean 24-h , daytime , and night-time heart rate , 24-h systolic BP load , systolic and diastolic BP dipping in all groups of patients were similar to those of the controls . In contrast , mean 24-h diastolic BP was higher in the URA group than those of the control group , but this finding showed no difference between the other patient groups and controls . The 24-h diastolic BP load was increased in the UAK group . In addition , an increased prevalence of hypertension was found in all of the patients groups . According to these results , we suggest that patients with a single kidney have potential risk factors for hypertension in the early childhood period . Compensatory hypertrophy of the remaining kidney may be seen in patients with UFSK . In adult animals , a compensatory increase in size following UNP is , for the most part , attributable to hypertrophy -LRB- an increase in cell size -RRB- , which is predominantly of proximal tubular origin . In young animals , renal growth is achieved primarily by cell multiplication , that is , hyperplasia -LSB- 3 -RSB- . In the present study , an inverse correlation was found between renal size SDS and 24-h MAP SDS , 24-h systolic and diastolic BP load SDS in all of the patients , but was not seen in the controls . Therefore , we think that there is an increased risk of hypertension in children without compensatory hypertrophy . To this end , we conclude that subtle alterations of renal function might be already present in children with UFSK , while no obvious pathological findings were made for BP or urinary protein excretion in the early period . However , an increased BP load was seen in these patients -LRB- particularly in patients without compensatory hypertrophy -RRB- . Nevertheless , this might not exclude an increased long-term risk for the development of hypertension or impaired renal function in this patient group . Because patients in the present study have a small sample and a shorter follow-up period , further prospective studies with a larger sample size and of longer term are suggested to find the relationship between these parameters .

O B I O O O O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

blood pressure
renal function
solitary kidney


Normative data on the Bonn Risk Index for calcium oxalate crystallization in healthy children Bonn Risk Index -LRB- BRI -RRB- is being used for the assessment of urinary calcium oxalate -LRB- CaOx -RRB- crystallization . There are no published data regarding BRI during growth . The objective of this study was to establish age - and sex-dependent BRI values in healthy children and adolescents . A total of 1,050 Caucasian subjects aged 3 -- 18 years -LRB- 525 males , 525 females -RRB- without a history of kidney stone disease were enrolled in the cross-sectional study . The study group was divided into 15 ranges according to age , each comprising 70 subjects . Urinary ionized calcium -LSB- Ca2 + -RSB- was measured using a selective electrode while the onset of spontaneous crystallization was determined using a photometer and titrating with 40 mmol/L ammonium oxalate -LRB- Ox2 − -RRB- . The calculation of BRI value was based on the ratio of -LSB- Ca2 + -RSB- to the required amount of ammonium oxalate added to 200 ml of urine to induce crystallization . The median BRI was 0.26 1/L and the values of the 5th and 95th percentiles were 0.06 1/L and 1.93 1/L , respectively . BRI correlated positively with body-area-related BRI -LRB- 1/L × 1.73 m2 -RRB- -LRB- R = 0.18 ; P < 0.05 -RRB- , whereas a negative correlation was found between BRI and body weight -LRB- 1/L × kg -RRB- -LRB- R = − 0.85 ; P < 0.05 -RRB- . Neither sex nor age differences were detected in BRI across studied children and adolescents . The values of Bonn Risk Index were constant during growth and there was a limited influence of age and sex on BRI in children over 3 years of age . The BRI may be valuable in the evaluation of pediatric patients at risk for kidney stones , particularly if the BRI from stone formers is demonstrated to be higher than in normal children . Introduction Urolithiasis is a frequently reported condition in children and is diagnosed even in neonates and infants -LSB- 1 , 2 -RSB- . The disease may be the first sign of congenital and acquired metabolic disturbances , or the consequence of anatomic or genetic abnormalities -LSB- 2 -RSB- . The majority of kidney stones are composed of calcium oxalate and calcium phosphate -LSB- 1 -RSB- . Insight into this pathology is increasing and is focused on the pathogenesis of deposit formation in the urinary tract -LSB- 3 -- 5 -RSB- . Investigation is being conducted into more effective methods which would enable the detection of risk factors for urolithiasis . One of the risk factors is an increase in the crystallization of calcium oxalate -LRB- CaOx -RRB- in urine . Kavanagh and Laube recently published a review of methods used to assess the crystallization of CaOx in urine -LSB- 6 -RSB- . During the last few years , activity products -LRB- AP -RRB- of crystallization have usually been assessed by means of the APCaOx index or as the relative supersaturation -LRB- RS -RRB- of urinary calcium oxalate -LRB- RSCaOx -RRB- using the computer program EQUIL -LSB- 7 , 8 -RSB- . Laube et al. showed that the ratio of calcium ions -LSB- Ca2 + -RSB- to the amount of ammonium oxalate added to 200 ml of urine to induce crystallization -LSB- designated here as -LRB- Ox2 − -RRB- -RSB- may be , at the moment of spontaneous crystallization of CaOx , an indicator of the risk of CaOx crystal formation -LSB- 9 -RSB- . The authors made this determination with a direct urine collection , without an initial processing . This ratio is known as the Bonn Risk Index -LRB- BRI -RRB- : BRI = -LSB- Ca2 + -RSB- / -LRB- Ox2 − -RRB- 1/L -LSB- 9 , 10 -RSB- . Due to its characteristics , this index is an accurate indicator of the individual state of balance between the quantities of the most important promoters and inhibitors of the crystallization process within urine -LSB- 9 , 10 -RSB- . Measuring BRI is simple , cost-effective , and the results are repeatable . In patients with calculi formation , CaOx assessed using BRI is significantly higher when compared to healthy subjects -LSB- 9 -RSB- . A lack of published studies concerning BRI in pediatric patients led us to conduct the study in children and adolescents . The purpose of this study was to define the BRI value in healthy subjects aged 3 -- 18 years , in relation to age and sex . Materials and methods The study was performed on a group of 1,050 healthy Caucasian children and adolescents -LRB- group I -RRB- aged 3 -- 18 years -LRB- mean ± SD : 10.51 ± 4.33 -RRB- , comprised of 525 boys and 525 girls . The study population was divided into 15 age groups , consisting of 70 children in each 1-year group -LRB- 35 boys and 35 girls -RRB- . The children reported no history of dietary restrictions . All participants met the criteria of the standard dietary energy and nutrient intakes recommended in Poland -LSB- 11 -RSB- . These children were free of infection at the time of the examination -LRB- serum C-reactive protein CRP < 0.4 mg/dL , blood leukocyte count < 10 × 109/L -RRB- . Prior to inclusion , all participants were screened regarding serum levels of protein , albumin , calcium , phosphate , potassium , uric acid , creatinine and alkaline phosphatase as well as urine concentrations of citrate , oxalate , potassium , calcium and phosphate . Urinary dipstick testing -LRB- Bayer Diagnostics , Bridgend , UK -RRB- detecting nine parameters , including leukocytes , protein and blood , did not reveal any abnormalities . Children with a family history of kidney stones were excluded from the study . Subjects with diseases known to affect oxalate , calcium and phosphate metabolism and children treated with antibiotics were excluded . All children were screened using renal ultrasound examination to exclude urolithiasis -LRB- Toshiba SSH-140A apparatus ; probe Convex 3.75 MHz -RRB- . Participants and their legal guardians gave informed consent , and the study was approved by the Ethical Committee of the Medical University of Bialystok . Bonn Risk Index The Bonn Risk Index was assessed using the method of Laube -LSB- 12 -RSB- . Each child had a 24-h urine collection into sterile containers , without additional preserving substances , which was stored at 4 °C . The testing was always performed twice using the same urine collection from each subject . Two consecutive urine samples -LRB- each 200 mL -RRB- were incubated immediately after collection , at a temperature of 37 °C and the calcium ion concentration was measured using calcium ion-selective electrodes of type Rapilab 855 -LRB- Bayer , Germany -RRB- and titrated with ammonium oxalate solution -LRB- 40 mmol/L -RRB- at a rate of 0.75 mL/min . The onset of spontaneous crystallization was detected using an Eppendorff photometer -LRB- filter 585 nm -RRB- with a decrease in light transmission to 98 % of the initial value . Each analysis was repeated twice . The BRI is presented as -LSB- Ca2 + -RSB- mmol/L / -LRB- Ox2 − -RRB- mmol = 1/L . Calibration and quality assurance procedures , based on the calibration curves , were conducted every day . Statistical analysis was performed using the program Statistica 6.0 PL . Mann-Whitney test was used for the analysis of two non-parametric independent variables , with P < 0.05 considered statistically significant . Assessment of the rank of two independent variables was conducted using Spearman correlation , with P < 0.05 considered statistically significant . For the purpose of plotting the curve of spontaneous crystallization -LRB- an association between the number of calcium ions and the amount of added ammonium oxalate leading to the spontaneous crystallization -RRB- , we used the computer program with the range of values as a scatterplot with the option of adding curves . Results The characteristics of the study group are presented in Fig. 1 . The anthropometric traits of participants , based on weight and height measurements and body mass index -LRB- BMI -RRB- , were within the normal range in each subgroup , relative to the Polish references described by other authors -LSB- 13 -RSB- . Fig. 1Body mass index -LRB- BMI -RRB- in studied girls and boys aged 3 -- 18 years compared to age and sex-matched reference range Figure 2 shows the detailed results for the whole study group for BRI , defined as the ratio of -LSB- Ca2 + -RSB- concentration in urine to the amount of added ammonium oxalate -LRB- Ox2 − -RRB- necessary for the spontaneous crystallization of CaOx . BRI in healthy children ranged between 0.06 and 1.93 1/L . The values between the 5th and 95th percentiles are found between the two borderline arrows . This diagram also presents the minimum and maximum concentrations of -LSB- Ca2 + -RSB- and the required amount of added oxalate -LRB- Ox2 − -RRB- . The concentration of -LSB- Ca2 + -RSB- in urine ranged from 0.25 mmol/L -LRB- 5th percentile -RRB- to 0.89 mmol/L -LRB- 95th percentile -RRB- with a median of 0.42 mmol/L , and an amount of added -LRB- Ox2 − -RRB- ranging from 0.46 mmol -LRB- 5th percentile -RRB- to 3.53 mmol -LRB- 95th percentile -RRB- with a median of 1.65 mmol . Fig. 2The spontaneous crystallization of CaOx in urine of 1,050 children aged 3.00 -- 17.99 years . The x-axis shows amount of ammonium oxalate -LRB- Ox2 − -RRB- in mmol necessary for the onset of spontaneous crystallization . The y-axis shows the concentration of calcium ions -LSB- Ca2 + -RSB- before adding Ox2 − . The extremes of the hyperbola represent minimum and maximum values . The minimum hyperbola is defined by the equation -LSB- Ca2 + -RSB- = 0.27 / -LRB- Ox2 − -RRB- , and the maximum is -LSB- Ca2 + -RSB- = 1.67 / -LRB- Ox2 − -RRB- . The BRI values for the 5th to the 95th percentile are found between the hyperbolas -LSB- Ca2 + -RSB- = 0.39 / -LRB- Ox2 − -RRB- and -LSB- Ca2 + -RSB- = 0.94 / -LRB- Ox2 − -RRB- , median -LSB- Ca2 + -RSB- = 0.65 / -LRB- Ox2 − -RRB- Figure 3 presents the BRI values in children representing various age groups . We considering the subjects in two main subgroups , younger children aged 3 -- 9 years , and older children and adolescents aged 10 -- 18 years . In children 3 -- 9 years of age , the lowest values of BRI were found in the youngest children , i.e. those 3 years old -LRB- median 0.18 1/L -RRB- , whilst the highest values were found in 9-year-old children -LRB- median 0.34 1/L -RRB- . However , statistical analyses did not show a difference between the values across the various age groups . The lowest median BRI value was 0.03 1/L in 9-year old children , whilst the highest median value was 2.48 1/L in 4-year-old children . The BRI values for younger children corresponding to the 5th percentile ranged from 0.03 -- 0.08 1/L , and the 95th percentile from 1.38 -- 2.27 1/L . Fig. 3Bonn Risk Index -LRB- BRI -RRB- in the whole studied group -LRB- left box -RRB- and in separate 1-year age groups for children aged 3 -- 18 years In older children and adolescents aged 10 -- 18 years , the lowest BRI values were found in the participants who were 12 years old -LRB- median 0.17 1/L -RRB- , whilst the highest were in 17-year-old adolescents -LRB- median 0.31 1/L -RRB- -LRB- Fig. 3 -RRB- . However , statistical analysis did not show significant differences between the age subgroups . The minimum value of BRI was 0.02 1/L , and was found in 11-year-old children , whereas the maximum value was 3.1 1/L in children aged 10 and 17 years . The BRI values for older children corresponding to the 5th percentile ranged between 0.05 and 0.13 1/L , whilst the 95th percentile was from 1.69 -- 2.66 1/L . The crystallization values of CaOx , based on BRI in healthy children aged 3 -- 18 , did not exceed 2.66 1/L . No significant differences were found in the BRI values between boys and girls in either age group . Table 1 presents the BRI and BRI related to the 1.73 m2 body surface area and body mass -LRB- kg -RRB- . The median BRI in relation to body surface area -LRB- 1/L × 1.73 m2 -RRB- was 0.39 1/L × 1.73 m2 , with 5th and 95th percentile medians of 0.09 and 3.01 1/L × 1.73 m2 , respectively . However , the median BRI in relation to 1 kg of weight was 0.008 1/L × kg with corresponding 5th and 95th percentiles of 0.0015 and 0.06 1/L × kg , respectively . A weak positive correlation was found between BRI and BRI/1 .73 m2 -LRB- R = 0.18 , P < 0.05 -RRB- , and a negative correlation was found between BRI/1 .73 m2 and BRI/kg -LRB- R = − 0.86 , P < 0.05 -RRB- . No differences were found between the values of BRI/1 .73 m2 and BRI/kg in the various age groups or in relation to sex . Table 1Bonn Risk Index values in children aged 3 -- 18 years in relation to body surface area and body weight MedianMinimumMaximum5th percentile95th percentileBRI -LRB- 1/L -RRB- 0.260.023.100.061.93 BRI/1 .73 m2 -LRB- 1/L × 1.73 m2 -RRB- 0.390.036.650.093.01 BRI/kg -LRB- 1/L × kg -RRB- 0.0080.00060.150.00150.06 Discussion Urinary stones are considered a major health problem in society , both in adults and in children , due to their recurrent nature and the cost of treatment -LSB- 14 -RSB- . The pathogenic pathways leading to stone formation in kidneys have not been fully explained . During processes of calculus formation , a number of phenomena have been reported such as excess of crystallizing substances , nucleation , crystallization , aggregation and stone formation -LSB- 15 , 16 -RSB- . However , it has not been explained why calculi do not form in all subjects , despite a large amount of urinary crystallization products . Over the past few years , there have been many attempts to define the risk factors leading to urinary stone formation on the basis of the ability to form oxalate crystals , a main component of calculi -LSB- 7 , 8 , 17 -RSB- . Tiselius et al. described the practical importance of assessing the activity of calcium oxalate ions in urine using the APCaOx index -LSB- 7 -RSB- . Stone formation has also been evaluated in terms of excess urinary calcium oxalate , using the computer program EQUIL -LSB- 18 , 19 -RSB- . Laube et al. showed a strong correlation between the concentration of free calcium ions -LSB- Ca2 + -RSB- in urine and the quantity of ammonium oxalate -LRB- Ox2 − -RRB- added to invoke spontaneous urinary crystallization of CaOx -LSB- 9 -RSB- . The authors suggested that the BRI index in healthy subjects was significantly lower than in those forming urinary calculi . The study , based on a group of 72 healthy subjects , provided mean BRI values of 1.05 ± 1.038 1/L with a range of 0.06 -- 4.89 1/L . In other studies involving 85 healthy adult subjects , the mean BRI values were similar , 0.89 ± 0.91 1/L . Higher BRI values have been described by Lewandowski et al. whose study group of 15 Caucasian adults demonstrated a mean BRI of 4.90 1/L , and 15 African adults had a mean BRI of 2.04 1/L -LSB- 10 -RSB- . The literature review did not reveal any larger or more comprehensive studies regarding BRI in children . Our findings in the large group of healthy children showed that the normal BRI value ranged from 0.06 1/L -LRB- 5th percentile -RRB- to 1.93 1/L -LRB- 95th percentile -RRB- . The maximum values obtained in children were lower than those described by other authors in adult populations -LSB- 6 , 9 , 20 -RSB- . This may be due to the fact that the mechanism which inhibits crystal formation in children 's urine is more effective when compared to adults . Teller et al. observed that urinary glycosaminoglycans in children reduced the aggregation of crystals more effectively than in adults -LSB- 21 -RSB- . A similar age-related effect regarding stone formation has been observed by Bergsland et al. , who showed that the urine of subjects aged less than 20 years produced a strong inhibitory effect on crystal formation -LSB- 22 -RSB- . Ricchiuti et al. investigated the process in boys aged less than 10 years and found increased activity of plasma protease inhibitor -LRB- inter-alpha inhibitor -RRB- , blocking urinary crystallization during various stages -LSB- 23 -RSB- . Our results did not show a significant difference in BRI values between boys and girls . A minor difference was found in relation to age , but this was not significant . The BRI/1 .73 m2 and BRI/kg behaved similarly . High correlations between BRI , BRI and body weight , and BRI and body surface area of studied subjects enable practical , more objective use of BRI and allow for comparisons between individuals . For this reason , these results are presented as median values with ranges for the 5th to 95th percentiles for the whole study group . The study has several limitations . So far , the use of our normative data appears to be limited to the Polish population . It is difficult to relate the results to other geographical regions or to different ethnic groups as there are no published data regarding BRI in children . Further comparative and prospective investigations are needed because a cross-sectional study is not able to reveal whether some children with a normal BRI value will be at risk for stone disease in the future . Moreover , some studied children may have had urolithiasis despite normal results of renal ultrasound . However , this study provided consistent normative data on BRI , due to both the large age representation and the stringent selection criteria . In summary , the Bonn Risk Index , expressed as the ratio of ionized calcium to the amount of ammonium oxalate necessary to initiate spontaneous CaOx urinary crystal formation , is lower in healthy children and adolescents aged 3 -- 18 years than in studies of adults by other authors . The BRI during growth appears to be independent of age and sex . Thus , our results may contribute to the effective screening of kidney stone disease in pediatric subjects . We conclude that the BRI may be valuable in the evaluation of pediatric patients at risk for kidney stones , particularly if the BRI from stone formers is demonstrated to be higher than in normal children .

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