bluuebunny/crossref_metadata_2025 huggingface dataset:
Data Collection Systems for Weight Loss Surgery: An Evidence‐Based Assessment
Authors: Hutter Matthew M. , Crane Martin , Keenan Maureen , Snow Roger L. , Schneider Benjamin E. , Cella Robert J.
Published: April 2008

Objective: To evaluate the existence and efficacy of data collection systems for weight loss surgery (WLS) and establish evidence‐based guidelines for the development of a statewide WLS registry in Massachusetts.

Research Methods and Procedures: We conducted two systematic searches of English language literature in MEDLINE. The first was on data collection registries related to WLS; the second was an expanded search encompassing other surgical fields (e.g., cardiac and thoracic surgery) and registries (i.e., cancer). Fourteen articles were found to be pertinent. Data were extracted, and evidence categories were assigned according to a grading system based on established evidence‐based models. Recommendations were derived from these literature reviews and expert opinion.

Results: This task group found that there are no standardized data collection systems for WLS in Massachusetts (or any other states) and no mandated reporting of WLS‐specific outcomes. We described existing WLS databases and systems in other surgical fields. Recommendations focused on the importance and feasibility of data collection for WLS and the need to conduct a pilot study and explore options for creating a statewide WLS database.

Discussion: A statewide WLS data collection system would optimize patient care by enabling the collection, analysis, and dissemination of best practice data. A broad‐based effort is needed to meet challenges involved in defining and implementing such a system.
Changes in Insulin Secretion and Glucose Metabolism Induced by Dexamethasone in Lean and Obese Females
Authors: Besse Christine , Nicod Nathalie , Tappy Luc
Published: April 2008

Objective: In healthy lean individuals, changes in insulin sensitivity occurring as a consequence of a 2‐day dexamethasone administration are compensated for by changes in insulin secretion, allowing glucose homeostasis to be maintained. This study evaluated the changes in glucose metabolism and insulin secretion induced by short‐term dexamethasone administration in obese women.

Research Methods and Procedures: Eleven obese women with normal glucose tolerance were studied on two occasions, without and after 2 days of low‐dose dexamethasone administration. A two‐step hyperglycemic clamp (7.5 and 10 mM glucose) with 6, 6 2H2 glucose was used to assess insulin secretion and whole body glucose metabolism. Results were compared with those obtained in a group of eight lean women.

Results: Without dexamethasone, obese women had higher plasma insulin concentrations in the fasting state, during the first phase of insulin secretion, and at the two hyperglycemic plateaus. However, they had normal whole body glucose metabolism compared with lean women, indicating adequate compensation. After dexamethasone, obese women had a 66% to 92% increase in plasma insulin concentrations but a 15.4% decrease in whole body glucose disposal. This contrasted with lean women, who had a 91% to 113% increase in plasma insulin concentrations, with no change in whole body glucose disposal.

Discussion: Dexamethasone administration led to a significant reduction in whole body glucose disposal at fixed glycemia in obese but not lean women. This indicates that obese women are unable to increase their insulin secretion appropriately.
Pediatricians’ Own Weight: Self‐perception, Misclassification, and Ease of Counseling
Authors: Perrin Eliana M. , Flower Kori B. , Ammerman Alice S.
Published: April 2008

Objectives: Pediatricians underdiagnose overweight and feel ineffective at counseling. Given the relationship between physicians’ health and health habits and counseling behaviors, we sought to determine the 1) percentage of pediatricians who are overweight; 2) accuracy of pediatricians’ own weight status classification; and 3) relationship between weight self‐perception and perceived ease of obesity counseling.

Research Methods and Procedures: This study was a cross‐sectional, mail survey of North Carolina pediatricians that queried about their weight status and ease of counseling. Accuracy of pediatricians’ self‐classification of weight status was compared with BMIs derived from self‐reported height and weight. Using logistic regression, controlling for potential confounding variables, we examined the association between weight perception and ease of counseling.

Results: The unadjusted response rate was 62%, and the adjusted response rate was 71% (n = 355). Nearly one‐half (49%) of overweight pediatricians did not identify themselves as such. Men had greater adjusted odds of misclassifying overweight than women [odds ratio (OR), 3.61; 95% confidence interval (CI) = 1.81, 7.21]. Self‐classified “thin” pediatricians had nearly six times the odds of reporting more counseling difficulty as a result of their weight than “average” weight pediatricians (OR = 5.69; 95% CI = 2.30, 14.1), and self‐identified “overweight” pediatricians reported nearly four times as great counseling difficulty as “average” weight physicians (OR = 3.84; 95% CI = 1.11, 13.3), after adjustment for self‐reported BMI weight status and other potential confounders.

Discussion: The roles that physician weight misclassification and self‐perception potentially play in influencing rates of obesity counseling warrant further research.
Knee Structural Alteration and BMI: A Cross‐sectional Study
Authors: Ding Changhai , Cicuttini Flavia , Scott Fiona , Cooley Helen , Jones Graeme
Published: April 2008

Objective: To describe the associations among BMI, knee cartilage morphology, and bone size in adults.

Research Methods and Procedures: A cross‐sectional convenience sample of 372 male and female subjects (mean age, 45 years; range, 26 to 61 years) was studied. Knee articular cartilage defect score (0 to 4) and prevalence (defect score of ≥2), volume, and thickness, as well as bone surface area and/or volume, were determined at the patellar, tibial, and femoral sites using T1‐weighted fat‐saturation magnetic resonance imaging. Height, weight, BMI, and radiographic osteoarthritis were measured by standard protocols.

Results: In multivariate analysis in the whole group, BMI was significantly associated with knee cartilage defect scores (β: +0.016/kg/m2 to +0.083/kg/m2, all p < 0.05) and prevalence (odds ratio: 1.05 to 1.12/kg/m2, all p < 0.05 except for the lateral tibiofemoral compartment). In addition, BMI was negatively associated with patellar cartilage thickness only (β = −0.021 mm/kg/m2; p = 0.039) and was positively associated with tibial bone area (medial: β = +7.1 mm2/kg/m2, p = 0.001; lateral: β = +3.2 mm2/kg/m2, p = 0.037). Those who were obese also had higher knee cartilage defect severity and prevalence and larger medial tibial bone area but no significant change in cartilage volume or thickness compared with those of normal weight.

Discussion: This study suggests that knee cartilage defects and tibial bone enlargement are the main structural changes associated with increasing BMI particularly in women. Preventing these changes may prevent knee osteoarthritis in overweight and obese subjects.
Additive Interactions of Maternal Prepregnancy BMI and Breast‐feeding on Childhood Overweight
Authors: Li Chaoyang , Kaur Harsohena , Choi Won S. , Huang Terry T.‐K. , Lee Rebecca E. , Ahluwalia Jasjit S.
Published: April 2008

Objective: To examine the interactions of maternal prepregnancy BMI and breast‐feeding on the risk of overweight among children 2 to 14 years of age.

Research Methods and Procedures: The 1996 National Longitudinal Survey of Youth, Child and Young Adult data in the United States were analyzed (n = 2636). The weighted sample represented 51.3% boys, 78.0% whites, 15.0% blacks, and 7.0% Hispanics. Childhood overweight was defined as BMI ≥95th percentile for age and sex. Maternal prepregnancy obesity was determined as BMI ≥30 kg/m2. The duration of breast‐feeding was measured as the weeks of age from birth when breast‐feeding ended.

Results: After adjusting for potential confounders, children whose mothers were obese before pregnancy were at a greater risk of becoming overweight [adjusted odds ratio (OR), 4.1; 95% confidence interval (CI), 2.6, 6.4] than children whose mothers had normal BMI (<25 kg/m2; p < 0.001 for linear trend). Breast‐feeding for ≥4 months was associated with a lower risk of childhood overweight (OR, 0.6; 95% CI, 0.4, 1.0; p = 0.06 for linear trend). The additive interaction between maternal prepregnancy obesity and lack of breast‐feeding was detected (p < 0.05), such that children whose mothers were obese and who were never breast‐fed had the greatest risk of becoming overweight (OR, 6.1; 95% CI, 2.9, 13.1).

Discussion: The combination of maternal prepregnancy obesity and lack of breast‐feeding may be associated with a greater risk of childhood overweight. Special attention may be needed for children with obese mothers and lack of breast‐feeding in developing childhood obesity intervention programs.
Obesity and the Use of Health Care Services
Authors: Bertakis Klea D. , Azari Rahman
Published: April 2008

Objective: This study investigated differences in the use of health care services and associated costs between obese and nonobese patients.

Research Methods and Procedures: New adult patients (N = 509) were randomly assigned to primary care physicians at a university medical center. Their use of medical services and related charges was monitored for 1 year. Data collected included sociodemographics, self‐reported health status using the Medical Outcomes Study Short Form‐36, evaluation for depression using the Beck Depression Index, and measured height and weight to calculate BMI.

Results: Obese patients included a significantly higher percentage of women and had higher mean age, lower mean education, lower mean health status, and higher mean Beck Depression Index scores. Obese patients had a significantly higher mean number of visits to both primary care (p = 0.0005) and specialty care clinics (p = 0.0006), and a higher mean number of diagnostic services (p < 0.0001). Obese patients also had significantly higher primary care (p = 0.0058), specialty clinic (p = 0.0062), emergency department (p = 0.0484), hospitalization (p = 0.0485), diagnostic services (p = 0.0021), and total charges (p = 0.0033). Controlling for health status, depression, age, education, income, and sex, obesity was significantly related to the use of primary care (p = 0.0364) and diagnostic services (p = 0.0075). There was no statistically significant relationship between obesity and medical expenditures in any of the five categories or for total charges.

Discussion: Obesity is a chronic condition requiring long‐term management, with an emphasis on prevention. If this critical health issue is not appropriately addressed, the prevalence of obesity and obesity‐related diseases will continue to grow, resulting in escalating use of health care services.
Effect of Dietary Carbohydrate Source on the Development of Obesity in Agouti Transgenic Mice**
Authors: Morris Kristin L. , Zemel Michael B.
Published: April 2008

Objectives: Our objective was to evaluate the effects of a qualitative change in dietary carbohydrate source on body weight and adiposity in a rodent model of diet‐induced obesity.

Research Methods and Procedures: We evaluated the effects of high‐fat diets (basal) varying in carbohydrate source in aP2‐agouti transgenic mice. In the ad libitum study, animals were given free access to the basal diet or one of four test diets for 6 weeks. In two of the diets, dietary carbohydrate was derived from a single source: mung bean noodles (MUNG) or rolled oats (ROLL). The remaining diets were designed to mimic commercially available instant oatmeal with added sugar (IO‐S) or flavored instant oatmeal (IO‐F). In the energy‐restricted study, animals were given ad libitum access to the basal diet for 6 weeks. Subsequently, animals were assigned to one of six treatment groups for 6 weeks. One group was continued on the basal diet ad libitum. The remaining groups were maintained with energy restriction (70% ad libitum) on either the basal, MUNG, ROLL, IO‐S, or IO‐F diet.

Results: Subcutaneous fat pad mass was significantly higher (p < 0.05) in the energy‐restricted basal and IO‐S groups compared with the energy‐restricted ROLL diet. Similarly, visceral fat pad mass was significantly lower with ROLL and MUNG diets (p < 0.05 for both) compared with basal and IO‐S diets, and the insulin:glucose ratio was reduced (by 23% to 34%, p < 0.05) in these two diets compared with all others. In ad libitum‐fed animals, liver fatty acid synthase expression was 43% to 62% lower (p < 0.05) with ROLL and MUNG diets compared with all others.

Discussion: These data suggest that a qualitative change in dietary carbohydrate source modulates body weight and adiposity.
Leptin Receptor Gene Variation Predicts Weight Change in Subjects with Impaired Glucose Tolerance
Authors: Zacharova Jelena , Chiasson Jean‐Louis , Laakso Markku ,   STOP‐NIDDM Study Group
Published: April 2008

The leptin receptor (OB‐R) gene is a promising candidate gene for type 2 diabetes, because leptin and its receptor play an important role in insulin secretion and the development of obesity. Therefore, we studied whether the pentanucleotide insertion polymorphism of the 3′‐untranslated region (3′UTR) of the OB‐R gene has an influence on the conversion from impaired glucose tolerance (IGT) to type 2 diabetes in the STOP‐Noninsulin‐Dependent Diabetes Mellitus trial. The STOP trial was a longitudinal, double‐blind, placebo‐controlled randomized trial that included 1429 subjects with IGT from high‐risk populations. Using the restriction fragment length polymorphism method, we genotyped 770 subjects whose DNA was available for the insertion/deletion polymorphism of the 3′UTR of the OB‐R gene. We did not find a relationship between the OB‐R polymorphism and the conversion from IGT to type 2 diabetes (p = 0.747). However, the insertion allele was associated with a significant reduction in weight (p = 0.016), BMI (p = 0.009), and waist circumference (p = 0.006) in all subjects. Women carrying the I allele had a larger waist circumference change (p = 0.036), whereas men lost more weight and had a greater decrease in BMI. The pentanucleotide insertion/deletion polymorphism in the 3′UTR of the OB‐R gene did not influence the conversion to type 2 diabetes in obese patients with IGT. However, this polymorphism was associated with a significant weight change, suggesting that it may potentially modulate the risk for type 2 diabetes.
Apolipoprotein A‐II Polymorphism and Visceral Adiposity in African‐American and White Women
Authors: Lara‐Castro Cristina , Hunter Gary R. , Lovejoy Jennifer C. , Gower Barbara A. , Fernández José R.
Published: April 2008

To determine the association between the −265 T to C substitution in the apolipoprotein A‐II (APOA‐II) gene and levels of visceral adipose tissue (VAT) in a group of premenopausal African‐American and white women, we genotyped 237 women (115 African‐American and 122 white) for this polymorphism. Body composition was assessed by DXA, and VAT was determined from a single computed tomography scan. In addition to VAT, we examined the association between the polymorphism and other phenotypes (total body fat, total abdominal adipose tissue, and subcutaneous abdominal adipose tissue). The mutant C allele in the APOA‐II gene was less frequent in African‐American compared with white women, 23% vs. 36%, respectively (p < 0.01). VAT was significantly higher in carriers of the C allele compared with noncarriers after adjustment for total body fat (p < 0.05). When separate analyses by ethnic group were conducted, the association between the polymorphism and VAT was observed in white (p < 0.05) but not African‐American (p = 0.57) women. There was no association between the polymorphism and the other phenotypes. These results indicate a significant association between the T265C APOA‐II polymorphism and levels of VAT in premenopausal women. This association is present in white but not African‐American women.
Food Viscosity Influences Caloric Intake Compensation and Body Weight in Rats
Authors: Davidson Terry L. , Swithers Susan E.
Published: April 2008

Objective: To determine the effects of food viscosity on the ability of rats to compensate for calories in a dietary supplement.

Research Methods and Procedures: In a series of four experiments, rats consumed dietary supplements equated for caloric and nutritive content but differing in viscosity. Experiments 1 to 3 examined the ability of the rats to compensate for the calories consumed in low‐ compared with high‐viscosity premeals by reducing intake of a subsequent test meal. Caloric compensation was assessed with a wide range of premeal viscosity levels and with two different non‐nutritive thickening agents. Experiment 4 assessed the effects of consuming daily a low‐viscosity compared with an equicaloric high‐viscosity dietary supplement on longer term body weight gain.

Results: Consuming a lower viscosity premeal was followed by significantly more caloric intake (i.e., less caloric compensation) compared with consuming premeals with higher viscosity levels. This effect was not specific to one thickening agent. Furthermore, rats given a low‐viscosity supplement daily gained significantly more weight over a 10‐week period compared with rats given a high‐viscosity supplement.

Discussion: The results of these experiments suggest that food viscosity may be an important determinant of short‐term caloric intake and longer term body weight gain.
Mice with Low Metabolic Rates Are Not Susceptible to Weight Gain When Fed a High‐Fat Diet
Authors: Hambly Catherine , Adams Andrew , Fustin Jean‐Michel , Rance Kellie A. , Bünger Lutz , Speakman John R.
Published: April 2008

Objective: Mice divergently selected for high or low food intake (FI) at constant body mass differ in their resting metabolic rates (RMRs). Low‐intake individuals (ML) have significantly lower RMR (by 30%) compared with those from the high‐intake line (MH). We hypothesized that MLs might, therefore, be more likely to increase their body and fat mass when exposed to a high‐fat diet (HFD).

Research Methods and Procedures: We exposed both lines to a diet with 44.9% calories from fat for 3 weeks while measuring FI, fecal production, and body mass and then returned the mice to standard chow.

Results: When exposed to the HFD, both lines significantly decreased their FI (MH, 40% to 45%; ML, 31% to 35%). This decrease occurred simultaneously with a significant increase in apparent energy absorption efficiency (AEAE). When returned to chow, FI and AEAE returned to the levels observed prior to HFD exposure. Because of the adjustments in FI, the absorbed energy was maintained in the MLs and, thus, body mass remained constant. The MH individuals overcompensated for the elevated energy content and AEAE on the HFD and, therefore, absorbed lower energy than when feeding on chow. These mice also did not significantly change their body mass when on the HFD and must have made adjustments in their energy expenditures. Both lines and both sexes increased in fat content on the HFD, but these effects were not different between lines or sexes.

Discussion: We found no support for the hypothesis that mice with low RMRs were more susceptible to weight gain when fed the HFD.
Energy Metabolic Profile of Mice after Chronic Activation of Central NPY Y1, Y2, or Y5 Receptors**
Authors: Henry Melanie , Ghibaudi Lorraine , Gao Jun , Hwa Joyce J.
Published: April 2008

Objective:Neuropeptide Y (NPY), a 36‐amino acid peptide with orexigenic properties, is expressed abundantly in the central nervous system and binds to several NPY receptor subtypes. This study examines the roles of the NPY Y1, Y2, and Y5 receptor(s) in energy homeostasis.

Research Methods and Procedures:We administered intracerebroventricular NPY (3 μg/d) or selective peptide agonists for the Y1, Y2, and Y5 receptor subtypes to C57Bl/6 mice for 6 days by mini‐osmotic pumps to assess the role of each receptor subtype in NPY‐induced obesity. Energy expenditure (EE) and respiratory quotient (RQ) were studied using indirect calorimetry. Adiposity was measured by DXA scanning and fat pad dissection. Insulin sensitivity was tested by whole‐blood glucose measurement after an insulin challenge.

Results:Central administration of the selective Y1 agonist, Y5 agonist, or NPY for 6 days in mice significantly increased body weight, adiposity, and RQ, with significant hyperphagia in the Y5 agonist‐ and NPY‐treated groups but not in the Y1 agonist‐treated group. The NPY, Y1, or Y5 agonist‐treated mice had little change in total EE during ad libitum and pair‐feeding conditions. Conversely, selective activation of the Y2 receptor reduced feeding and resulted in a significant, but transient, weight loss.

Discussion:Central activation of both Y1 and Y5 receptors increases RQ and adiposity, whereas only Y5 receptor activation reduces energy expended per energy ingested. Selective activation of Y2 autoreceptors leads to hypophagia and transient weight loss, with little effect on total EE. Our study indicates that all three NPY receptor subtypes may play a role in regulating energy homeostasis in mice.
Diet and Physical Activity Behaviors among Americans Trying to Lose Weight: 2000 Behavioral Risk Factor Surveillance System
Authors: Bish Connie L. , Blanck Heidi Michels , Serdula Mary K. , Marcus Michele , Kohl Harold W. , Khan Laura Kettel
Published: April 2008

Objective: To examine the prevalence and correlates of trying to lose weight among U.S. adults, describe weight loss strategies, and assess attainment of recommendations for weight control (eating fewer calories and physical activity).

Research Methods and Procedures: This study used the Behavioral Risk Factor Surveillance System, a state‐based telephone survey of adults ≥18 years of age (N = 184, 450) conducted in the 50 states, the District of Columbia, and Puerto Rico in 2000.

Results: The prevalence of trying to lose weight was 46% (women) and 33% (men). Women reported trying to lose weight at a lower BMI than did men; 60% of overweight women were trying to lose weight, but men did not reach this level until they were obese. Adults who had a routine physician checkup in the previous year and reported medical advice to lose weight vs. checkup and no medical advice to lose weight had a higher prevalence of trying to lose weight (81% women and 77% men vs. 41% women and 28% men, respectively). The odds of trying to lose weight increased as years of education increased. Among respondents who were trying to lose weight, ∼19% of women and 22% of men reported using fewer calories and ≥150 min/wk leisure‐time physical activity.

Discussion: A higher percentage of women than men were trying to lose weight; both sexes used similar weight loss strategies. Education and medical advice to lose weight were strongly associated with trying to lose weight. Most persons trying to lose weight were not using minimum recommended weight loss strategies.
Improved Prediction of Body Fat by Measuring Skinfold Thickness, Circumferences, and Bone Breadths
Authors: Garcia Ada L. , Wagner Karen , Hothorn Torsten , Koebnick Corinna , Zunft Hans‐Joachim F. , Trippo Ulrike
Published: April 2008

Objective: To develop improved predictive regression equations for body fat content derived from common anthropometric measurements.

Research Methods and Procedures: 117 healthy German subjects, 46 men and 71 women, 26 to 67 years of age, from two different studies were assigned to a validation and a cross‐validation group. Common anthropometric measurements and body composition by DXA were obtained. Equations using anthropometric measurements predicting body fat mass (BFM) with DXA as a reference method were developed using regression models.

Results: The final best predictive sex‐specific equations combining skinfold thicknesses (SF), circumferences, and bone breadth measurements were as follows: BFMNew (kg) for men = −40.750 + [(0.397 × waist circumference) + [6.568 × (log triceps SF + log subscapular SF + log abdominal SF)]] and BFMNew (kg) for women = −75.231 + [(0.512 × hip circumference) + [8.889 × (log chin SF + log triceps SF + log subscapular SF)] + (1.905 × knee breadth)]. The estimates of BFM from both validation and cross‐validation had an excellent correlation, showed excellent correspondence to the DXA estimates, and showed a negligible tendency to underestimate percent body fat in subjects with higher BFM compared with equations using a two‐compartment (Durnin and Womersley) or a four‐compartment (Peterson) model as the reference method.

Discussion: Combining skinfold thicknesses with circumference and/or bone breadth measures provide a more precise prediction of percent body fat in comparison with established SF equations. Our equations are recommended for use in clinical or epidemiological settings in populations with similar ethnic background.
Cross‐Talk between the Insulin and Leptin Signaling Systems in Rat Hypothalamus**
Authors: Carvalheira José B.C. , Torsoni Márcio A. , Ueno Mirian , Amaral Maria E. , Araújo Eliana P. , Velloso Lício A. , Gontijo José A.R. , Saad Mario J.A.
Published: April 2008

Objective: To investigate whether insulin and leptin share common intracellular signal transduction pathways and to determine whether these hormonal signaling systems modulate each other's action in rat hypothalamus.

Research Methods and Procedures: Male Wistar rats were studied after chronic implantation of an intracerebroventricular catheter into the third ventricle. Immunoprecipitation and immunoblotting were used to examine the activation of insulin and leptin signaling molecules in the rat hypothalamus.

Results: Insulin alone is able to produce molecular activation of insulin receptor substrates (IRSs)/phosphatidylinositol 3‐kinase (PI 3‐kinase)/Akt and mitogen‐activated protein (MAP) kinase signaling pathways in hypothalamus, whereas leptin alone activates MAP kinase and IRSs/PI 3‐kinase signaling with no effect on Akt. Combined infusion of leptin and insulin provokes a dual action. There was no quantitative potentialization of any single hormone's action on the elements of the insulin signaling pathway, IRSs/PI 3‐kinase/Akt, and MAP kinase. Conversely, leptin plus insulin leads to quantitative potentialization of molecular signaling through the Janus kinase/signal transducer and activator of transcription pathway.

Discussion: We provide evidence for a convergence of leptin and insulin signaling at the level of IRSs‐PI 3‐kinase and a divergence at the level of Akt. Moreover, our results indicate a direct and positive cross‐talk between insulin and leptin at the level of Janus kinase 2 and signal transducer and activator of transcription 3 tyrosine phosphorylation. This mechanism may serve to potentiate the activity of both insulin and leptin pathways and to increase stimulation in physiological processes such as the control of food intake and body weight, which are under the combined control of insulin and leptin.
Psychosocial and Behavioral Aspects of Bariatric Surgery
Authors: Sarwer David B. , Wadden Thomas A. , Fabricatore Anthony N.
Published: April 2008

Bariatric surgery has become an increasingly popular treatment option for individuals with extreme obesity (defined as a BMI ≥ 40 kg/m2) or those with less severe obesity accompanied by significant comorbidities. Sustained postoperative weight loss and improvements in obesity‐related health problems make bariatric surgery the most effective treatment for this population. Nevertheless, most experts agree that psychosocial and behavioral factors contribute to successful postoperative outcomes. This paper reviews the literature on the preoperative psychosocial status, eating behaviors, and quality of life of patients who seek bariatric surgery. In addition, the paper examines studies that investigated changes in these factors postoperatively. The review concludes with an agenda for future research in this area.
1, 25‐Dihydroxyvitamin D3 Modulation of Adipocyte Glucocorticoid Function
Authors: Morris Kristin L. , Zemel Michael B.
Published: April 2008

Objective: 1, 25‐Dihydroxyvitamin D3 dose dependently increases intracellular calcium in human adipocytes. We have demonstrated that suppression of circulating 1, 25‐dihydroxyvitamin D3 levels by increasing dietary calcium reduces adipocyte intracellular calcium and reduces adiposity in both humans and rodents, with preferential loss of trunk fat. Autocrine production of cortisol by adipocytes of mice overexpressing 11β‐hydroxysteroid dehydrogenase type 1 (11β‐HSD 1) in adipose tissue increases visceral adiposity, whereas knockout of 11β‐HSD 1 appears to attenuate truncal obesity. Accordingly, our objective was to investigate the role of 1, 25‐dihydroxyvitamin D3 in the modulation of adipocyte glucocorticoid metabolism.

Research Methods and Procedures: We examined the effect of 1, 25‐dihydroxyvitamin D3 or angiotensin II on cortisol production and expression using real‐time reverse transcriptase‐polymerase chain reaction of 11β‐HSD 1, angiotensin II receptor type 1 (AT1), and AT2 receptor in human adipocytes.

Results: Adipocytes produced negligible cortisol in the absence of substrate (cortisone). In the presence of cortisone (1 to 10 nM), there was significant cortisol production, which was dose dependently augmented (2‐ to 6‐fold, p < 0.001) by 1, 25‐dihydroxyvitamin D3 (0.1 to 10 nM). 1, 25‐Dihydroxyvitamin D3 dose dependently increased 11β‐HSD 1 expression up to 2‐fold (p < 0.01) in both the presence and absence of cortisone. In contrast, 1, 25‐dihydroxyvitamin D3 dose dependently decreased adipocyte AT1 expression (by 30% to 50%, p < 0.001) in both the presence and absence of cortisone, suggesting compensatory down‐regulation of AT1.

Discussion: We conclude that 1, 25‐dihydroxyvitamin D3 directly regulates adipocyte 11β‐HSD 1 expression and, consequently, local cortisol levels and that this may contribute to the preferential loss of visceral adiposity by high‐calcium diets.
Four‐Compartment Cellular Level Body Composition Model: Comparison of Two Approaches**
Authors: Shen Wei , St‐Onge Marie‐Pierre , Pietrobelli Angelo , Wang Jack , Wang ZiMian , Heshka Stanley , Heymsfield Steven B.
Published: April 2008

Objective: The aim of this study was to develop and compare two DXA‐based four‐compartment [body weight = body cell mass (BCM) + extracellular fluid (ECF) + extracellular solids (ECS) + fat] cellular level models.

Research Methods and Procedures: Total body potassium (TBK) model: BCM from TBK by whole‐body counting—ECFTBK = LST − [BCMTBK + 0.73 × osseous mineral (Mo)]. Bromide model: ECF from sodium bromide dilution—BCMBROMIDE = LST − (ECFBROMIDE + 0.73 × Mo); Mo and LST measurements came from DXA. The two approaches were evaluated in 99 healthy men and 118 women.

Results: BCM estimates were highly correlated (r = 0.97, p < 0.001), as were ECF estimates (r = 0.87, p < 0.001); a small statistically significant mean difference was present (mean ± SD; BCMTBK model, 30.4 ± 8.9 kg; BCMBROMIDE, 31.4 ± 9.3 kg; Δ = 1.0 ± 2.8 kg; p < 0.001; ECFTBK, 18.5 ± 4.2 kg; ECFBROMIDE, 17.5 ± 3.6 kg; Δ = 1.0 ± 2.8 kg; p < 0.001). A high correlation (r = 0.97, p < 0.001) and good agreement (38.9 ± 9.5 vs. 38.9 ± 9.5 kg; Δ = 0.0 ± 2.4 kg; p = 0.39) were present between TBW, derived as the sum of intracellular water from TBK and ECW from bromide, and measured TBW by 2H2O dilution.

Discussion: Two developed four‐compartment cellular level DXA models, one of which is appropriate for use in most clinical and research settings, provide comparable results and are applicable for BCM and ECF estimation of subject groups with hydration disturbances.
Dysregulation of the Autonomic Nervous System Can Be a Link between Visceral Adiposity and Insulin Resistance
Authors: Lindmark Stina , Lönn Lars , Wiklund Urban , Tufvesson Magnus , Olsson Tommy , Eriksson Jan W.
Published: April 2008

Objective: To evaluate the interplay among abdominal adipose tissue distribution, the cortisol axis, the autonomic nervous system, and insulin resistance.

Research Methods and Procedures: Two age‐, sex‐, and BMI‐matched groups were studied. Fifteen subjects were first‐degree relatives of patients with type 2 diabetes (R), and 15 had no family history of diabetes (controls, C). A hyperinsulinemic euglycemic clamp, cortisol measurements, and analysis of heart rate variability (HRV) were performed. Computed tomography was performed in a subgroup (n = 9 + 9) to determine abdominal adipose tissue distribution.

Results: R tended to be less insulin‐sensitive than C (M value 9.2 ± 1.0 vs 10.3 ± 0.7 mg/kg per minute, not significant). Stimulation with tetracosactin or corticotropin releasing hormone yielded lower peak serum cortisol levels in R (p = 0.03 and p = 0.06, respectively). The amount of visceral abdominal fat (VAT) tended to be greater in R. In all subjects, VAT was negatively correlated to insulin sensitivity (r = −0.93, p < 0.001). There was a positive association between VAT and resting heart rate (r = 0.70, p = 0.003) and sympathetic/parasympathetic ratio in HRV assessment after tilt (r = 0.53, p = 0.03). Subcutaneous abdominal tissue was not associated with insulin sensitivity or any of the hormonal or HRV assessments.

Discussion: Subjects genetically predisposed for type 2 diabetes had a tendency toward a larger amount of VAT and to lower insulin sensitivity compared with control subjects. The amount of visceral fat was strongly associated with insulin resistance and signs of a high ratio of sympathetic vs. parasympathetic reactivity. A large amount of visceral fat may act in concert with sympathetic/parasympathetic imbalance to promote the development of insulin resistance, and this may be partly independent of genetic background.
Prediction of Percentage Body Fat in Rural Thai Population Using Simple Anthropometric Measurements
Authors: Pongchaiyakul Chatlert , Kosulwat Vongsvat , Rojroongwasinkul Nipa , Charoenkiatkul Somsri , Thepsuthammarat Kaewjai , Laopaiboon Malinee , Nguyen Tuan V. , Rajatanavin Rajata
Published: April 2008

Objective: To develop and validate sex‐specific equations for predicting percentage body fat (%BF) in rural Thai population, based on BMI and anthropometric measurements.

Research Methods and Procedures: %BF (DXA; GE Lunar Corp., Madison, WI) was measured in 181 men and 255 women who were healthy and between 20 and 84 years old. Anthropometric measures such as weight (kilograms), height (centimeters), BMI (kilograms per meter squared), waist circumference (centimeters), hip circumference (centimeters), thickness at triceps skinfold (millimeters), biceps skinfold (millimeters), subscapular skinfold (millimeters), and suprailiac skinfold (millimeters) were also measured. The sample was randomly divided into a development group (98 men and 125 women) and a validation group (83 men and 130 women). Regression equations of %BF derived from the development group were then evaluated for accuracy in the validation group.

Results: The equation for estimating %BF in men was: %BF(men) = 0.42 × subscapular skinfold + 0.62 × BMI − 0.28 × biceps skinfold + 0.17 × waist circumference − 18.47, and in women: %BF(women) = 0.42 × hip circumference + 0.17 × suprailiac skinfold + 0.46 × BMI − 23.75. The coefficient of determination (R2) for both equations was 0.68. Without anthropometric variables, the predictive equation using BMI, age, and sex was: %BF = 1.65 × BMI + 0.06 × age − 15.3 × sex − 10.67 (where sex = 1 for men and sex = 0 for women), with R2 = 0.83. When these equations were applied to the validation sample, the difference between measured and predicted %BF ranged between ±9%, and the positive predictive values were above 0.9.

Discussion: These results suggest that simple, noninvasive, and inexpensive anthropometric variables may provide an accurate estimate of %BF and could potentially aid the diagnosis of obesity in rural Thais.
Intentional Weight Loss in Young Adults: Sex‐Specific Genetic and Environmental Effects
Authors: Keski‐Rahkonen Anna , Neale Benjamin M. , Bulik Cynthia M. , Pietiläinen Kirsi H. , Rose Richard J. , Kaprio Jaakko , Rissanen Aila
Published: April 2008

Objective: To explore eating styles associated with intentional weight loss (IWL) and to determine whether the genetic liability in IWL is entirely shared with genetic liability affecting BMI.

Research Methods and Procedures: As part of a longitudinal assessment of various health‐related behaviors in a large population‐based sample of twins, eating styles, BMI, and the number of times the study participants had intentionally lost ≥5 kg were assessed by questionnaire from 4667 male and female twins (22 to 27 years of age). Associations of eating styles and IWL were explored using polytomous logistic regression models adjusted for BMI. Sex‐specific bivariate structural equation modeling was used to explore genetic and environmental correlations of BMI and IWL.

Results: Individuals who had engaged in IWL exhibited markedly more restricting, overeating, and alternating restricting/overeating than those in the no‐IWL group. Snacking and eating in the evening were characteristic of women with at least two IWL attempts. Eating in response to visual and emotional cues was very pronounced in women who had engaged in IWL but much less so in men. IWL was estimated to have a heritability of 38% [95% confidence interval (CI), 19% to 55%] in men and 66% (95% CI, 55% to 75%) in women. The genetic covariance of BMI and IWL was 0.38 (95% CI, 0.28 to 0.47) for men and 0.45 (95% CI, 0.41 to 0.52) for women.

Discussion: Distinct sex differences exist in eating styles associated with IWL and in the heritability of IWL. Most genetic factors affecting BMI are different from those affecting IWL.
An SNP in the Adiponectin Gene Is Associated with Decreased Serum Adiponectin Levels and Risk for Impaired Glucose Tolerance
Authors: González‐Sánchez José L. , Zabena Carina A. , Martínez‐Larrad María T. , Fernández‐Pérez Cristina , Pérez‐Barba Milagros , Laakso Markku , Serrano‐Ríos Manuel
Published: April 2008

Adiponectin is a plasma protein produced by the adipose tissue. Hypoadiponectinemia has been associated with insulin resistance and several components of the metabolic syndrome (MS): type 2 diabetes, obesity, and dyslipidemia. We investigated whether single nucleotide polymorphisms (SNPs) at positions 45 and 276 in the adiponectin gene were associated with features of the MS in 747 unrelated Spanish subjects. The G allele of SNP45 and the G/G genotype of SNP276 were associated with impaired glucose tolerance (p = 0.020 and 0.042, respectively). The G/G genotype for SNP276 was associated with lower serum adiponectin levels as compared with the G/T and T/T genotypes (G/G, 10.10 ± 0.24 μg/mL; G/T, 10.98 ± 0.32 μg/mL; T/T, 12.00 ± 0.92 μg/mL; p = 0.015) even after adjustment for sex, age, BMI, waist‐to‐hip ratio, homeostasis model assessment index, and the degree of glucose tolerance (p = 0.040). We found a significant negative association of circulating adiponectin levels with waist‐to‐hip ratio (r = −0.42, p < 0.001), sagittal abdominal diameter (r = −0.24, p < 0.001), triglycerides (r = −0.32, p < 0.001), homeostasis model assessment index (r = −0.14, p = 0.001), and uric acid (r = −0.36, p < 0.001) and positive association with high‐density lipoprotein‐cholesterol (r = 0.41, p < 0.001). Our findings indicate that serum adiponectin levels are associated with several components of the MS. The SNP276 of the adiponectin gene may affect impaired glucose tolerance and hypoadiponectinemia.
Differential Expression of the Peripheral Benzodiazepine Receptor and Gremlin During Adipogenesis
Authors: Wade F. Marlene , Wakade Chandramohan , Mahesh Virendra B. , Brann Darrell W.
Published: April 2008

This study used the mRNA differential display technique to identify differentially expressed genes during the process of adipogenesis in the preadipocyte cell line, 3T3‐L1. 3T3‐L1 cells were treated with dexamethasone, isobutyl‐1‐methylxanthine, and insulin to induce differentiation into mature adipocytes. Cells were collected at three time‐points during differentiation: Day 0 (d0), or nondifferentiated; Day 3 (d3), during differentiation; and Day 10 (d10), >90% of the cells had differentiated into mature adipocytes. Initial studies yielded 18 potentially differentially regulated cDNA candidates (8 down‐regulated and 10 up‐regulated). Reverse Northern and Northern blots confirmed differential expression of six of the candidates. Four of the candidates up‐regulated on d3 and d10 were identified by sequence analysis to be lipoprotein lipase, a well‐known marker of adipocyte differentiation. A fifth candidate that was expressed in d0, but not d3 or d10, was identified as DRM/gremlin, a bone morphogenetic protein antagonist. Finally, a sixth candidate that was increased at d3 and d10 was identified as the peripheral benzodiazepine receptor, which has been implicated in proliferation, differentiation, and cholesterol transport in cells. This study is the first to show that peripheral benzodiazepine receptor and DRM/gremlin are expressed in preadipocyte cell lines and that they are differentially regulated during adipogenesis.
Change in Vascular Adhesion Protein‐1 and Metabolic Phenotypes after Vertical Banded Gastroplasty for Morbid Obesity
Authors: Li Hung‐Yuan , Lee Wei‐Jei , Chen Mei‐Ju , Chuang Lee‐Ming
Published: April 2008

Objective: The association between circulating vascular adhesion protein‐1 (VAP‐1) and metabolic phenotypes has been shown to be inconsistent. The current study explored whether the changes in serum VAP‐1 levels correlate with the changes in metabolic phenotypes after weight reduction surgery.

Research Methods and Procedures: Clinical characteristics and serum VAP‐1 levels in 20 morbidly obese subjects (mean BMI 38.84 kg/m2) were measured before and after vertical banded gastroplasty.

Results: Before surgery, serum VAP‐1 levels correlated positively with fasting plasma glucose (γ = 0.56, p = 0.01) and negatively with insulin levels (γ = −0.51, p = 0.021). After surgery, the changes in serum VAP‐1 levels were negatively correlated with the changes in waist circumference (γ = −0.57, p = 0.011), diastolic blood pressure (DBP) (γ = −0.56, p = 0.015), and mean arterial pressure (γ = −0.46, p = 0.055). In multivariate regression, serum VAP‐1 levels were negatively correlated with waist circumference (β = −2.36, p = 0.014) and DBP (β = −3.02, p = 0.017) after adjusting for age and gender. The change in DBP was negatively correlated with the change in VAP‐1 levels after adjusting for age, gender, and steady‐state plasma glucose.

Discussion: The results suggest that VAP‐1 levels are correlated with fasting glucose and insulin levels in morbidly obese subjects. After surgery, the changes in VAP‐1 levels were associated with changes in visceral adiposity and DBP. Serum VAP‐1 might modulate DBP independently from the changes in insulin resistance in morbidly obese people.
Corrigendum to: Broad-scale environmental influences on the abundance of saltwater crocodiles (Crocodylus porosus) in Australia
Authors: Fukuda Yusuke , Whitehead Peter , Boggs Guy
Published: April 2008

Saltwater crocodile (Crocodylus porosus) populations have recovered strongly across northern Australia over the 30 years since the species was protected from hunting. However, monitoring studies show large geographical variations in abundance across the Northern Territory, Queensland and Western Australia. The Northern Territory has considerably higher densities, raising questions about constraints on recovery in the other states. We examined broad-scale environmental influences on population abundance by modelling the species.environment relationships across northern Australia. The hypothesis-based models showed strong support for the linkage to (1) the ratio of total area of favourable wetland vegetation types (Melaleuca, grass and sedge to total catchment area, (2) a measure of rainfall seasonality, namely the ratio of total precipitation in the coldest quarter to total precipitation in the warmest quarter of a year, and (3) the mean temperature in the coldest quarter of a year. On the other hand, we were unable to show any clear negative association with landscape modification, as indicated by the extent of high-impact land uses or human population density in catchments. We conclude that geographical variations in crocodile density are mostly attributable to differences in habitat quality rather than the management regimes adopted in the respective jurisdictions.
The projected distributions of Mastacomys fuscus and Rattus lutreolus in south-eastern Australia under a scenario of climate change: potential for increased competition?
Authors: Green K. , Stein J. A. , Driessen M. M.
Published: April 2008

Animal distribution is strongly controlled by climate, especially at higher altitudes where harsher conditions favour fewer vertebrate species. A predicted consequence of climate change is increased pressure on these higher-altitude faunal communities by invasion of lower-altitude species more suited to warmer conditions. The distribution of two such species, the broad-toothed rat (Mastacomys fuscus) and swamp rat (Rattus lutreolus) (with the former generally occurring at higher altitude except in Tasmania), were examined using BIOCLIM. Modelled climate change with a 20% reduction in precipitation and a warming of 2.9°C at latitude 36°S (Snowy Mountains) and 3.4°C at 42°S (central Tasmania) suggests that M. fuscus will retreat to higher altitudes. The core areas of R. lutreolus will also contract, but significantly they will also move so that they overlap current core areas of M. fuscus on the mainland. Barrington Tops is the northernmost known location for M. fuscus and is climatically marginal. The recent invasion of Barrington Tops by R. lutreolus and decline of M. fuscus raises the question as to whether the modelled broader range changes will result in greater competition between the invading R. lutreolus and the cool-climate specialist M. fuscus, resulting in the further loss of the latter.
Habitat requirements of the yellow-footed antechinus (Antechinus flavipes) in box - ironbark forest, Victoria, Australia
Authors: Kelly Luke T. , Bennett Andrew F.
Published: April 2008

Understanding the habitat requirements of a species is critical for effective conservation-based management. In this study, we investigated the influence of forest structure on the distribution of the yellow-footed antechinus (Antechinus flavipes), a small dasyurid marsupial characteristic of dry forests on the inland side of the Great Dividing Range, Australia. Hair-sampling tubes were used to determine the occurrence of A. flavipes at 60 sites stratified across one of the largest remaining tracts of dry box–ironbark forest in south-eastern Australia. We considered the role of six potential explanatory variables: large trees, hollow-bearing trees, coppice hollows, logs, rock cover and litter. Logistic regression models were examined using an information-theoretic approach to determine the variables that best explained the presence or absence of the species. Hierarchical partitioning was employed to further explore relationships between occurrence of A. flavipes and explanatory variables. Forest structure accounted for a substantial proportion of the variation in occurrence of A. flavipes between sites. The strongest influence on the presence of A. flavipes was the cover of litter at survey sites. The density of hollow-bearing trees and rock cover were also positive influences. The conservation of A. flavipes will be enhanced by retention of habitat components that ensure a structurally complex environment in box–ironbark forests. This will also benefit the conservation of several threatened species in this dry forest ecosystem.