bluuebunny/crossref_metadata_2025 huggingface dataset:
The Obesity Epidemic: Metabolic Imprinting on Genetically Susceptible Neural Circuits
Authors: Levin Barry E.
Published: April 2008

The apparent obesity epidemic in the industrialized world is not explained completely by increased food intake or decreased energy expenditure. Once obesity develops in genetically predisposed individuals, their obese body weight is avidly defended against chronic caloric restriction. In animals genetically predisposed toward obesity, there are multiple abnormalities of neural function that prime them to become obese when dietary caloric density and quantity are raised. Once obesity is fully developed, these abnormalities largely disappear. This suggests that obesity might be the normal state for such individuals. Formation of new neural circuits involved in energy homeostasis might underlie the near permanence of the obese body weight. Such neural plasticity can occur during both nervous system development and in adult life. Maternal diabetes, obesity, and undernutrition have all been associated with obesity in the offspring of such mothers, especially in genetically predisposed individuals. Altered brain neural circuitry and function often accompanies such obesity. This enhanced obesity may then be passed on to subsequent generations in a feed‐forward, upward spiral of increasing body weight across generations. Such findings suggest a form of “metabolic imprinting” upon genetically predisposed neural circuits involved in energy homeostasis. Centrally acting drugs used for obesity treatment lower the defended body weight and alter the function of neural pathways involved in energy homeostasis. But they generally have no permanent effect on body weight or neural function. Thus, early identification of obesity‐prone mothers, infants, and adults and treatment of early obesity may be the only way to prevent the formation of permanent neural connections that promote and perpetuate obesity in genetically predisposed individuals.
Comparability of Resting Energy Expenditure in Nigerians and U.S. Blacks
Authors: Luke Amy , Rotimi Charles N. , Adeyemo Adebowale A. , Durazo‐Arvizu Ramon A. , Prewitt T. Elaine , Moragne‐Kayser Lisa , Harders Regina , Cooper Richard S.
Published: April 2008

Objective: To determine the influence of environmental factors on resting energy expenditure (REE) and its relationship to adiposity in two populations of West African origin, Nigerians and U.S. blacks.

Research Methods and Procedures: REE and body composition were measured in a cross‐sectional sample of 89 Nigerian adults (39 women and 50 men), and 181 U.S. black adults (117 women and 65 men). Both groups represent randomly selected population samples. REE was measured by indirect calorimetry after an overnight fast in both sites using the same instrument. Body composition was estimated using bioelectrical impedance analysis (BIA) in 72 Nigerians and 156 U.S. participants. Multivariate regression analysis was used to determine the significant predictors of REE. The analyses were repeated in a set of 17 Nigerians and 28 U.S. blacks in whom body composition was measured using deuterium dilution.

Results: U.S. black adults were significantly heavier and had both more fat‐free mass (FFM) and body fat than Nigerians. FFM was the only significant determinant of REE in both population groups, whether body composition was measured using BIA or deuterium dilution. The relationship between REE and body composition did not differ by site. There was no relationship between REE and adiposity.

Discussion: Differences in current environmental settings did not impact REE. The differences observed in mean levels of body fat between Nigerians and U.S. blacks were not the result of differences in REE adjusted for body composition.
Resemblance for Body Mass Index in Families of Obese African American and European American Women
Authors: Price R. Arlen , Reed Danielle R. , Guido Nicholas J.
Published: April 2008

Objective: We determined the levels of resemblance in body mass index (BMI) in large samples of families selected through obese African American and European American women.

Research Methods and Procedures: We examined correlations among relatives in 1185 European American and African American families ascertained through age‐matched obese women (BMI ≥ 30 kg/m2). A subset of 801 families were ascertained through extremely obese women (BMI ≥ 40 kg/m2).

Results: Parent‐offspring and sibling correlations ranged from 0.19 to 0.15, suggesting a moderate level of heritability in both groups. Mean BMI values for female relatives were lower for European Americans than for African Americans even though probands were matched, perhaps because the European American relatives regress to a lower population mean. We found significantly higher family correlations for height in European Americans, suggesting greater environmental variability among African Americans for factors affecting growth and physical development.

Discussion: Our results suggest a similar level of heritability of BMI in families of obese African American and European American women. Other genetic studies will be needed to determine the extent to which the same or different genes and environmental conditions contribute to an overall similar heritability in the two racial groups.
Partial Genome Scale Analysis of Gene Expression in Human Adipose Tissue Using DNA Array
Authors: Gabrielsson Britt L. , Carlsson Björn , Carlsson Lena M. S.
Published: April 2008

Objective: Large scale analysis of gene expression in adipose tissue provides a basis for the identification of novel candidate genes involved in the pathophysiology of obesity. Our goal was to explore gene expression in human adipose tissue at a partial genome scale using DNA array.

Research Methods and Procedures: Labeled cDNA, derived from human adipose tissue poly(A+) RNA, was hybridized to a DNA array containing over 18,000 human expressed sequence‐tagged (EST) clones. The results were analyzed by database searches.

Results: Homology searches of the 300 EST clones with highest hybridization signals revealed that 145 contained DNA sequences identical to known genes and 79 could be linked to UniGene clusters. Of the 145 identified genes, 136 were nonredundant and subsequently characterized with respect to function and chromosomal localization by searching MEDLINE, UniGene, GeneMap, OMIM, SWISS‐PROT, the Genome Database, and the Location Data Base. The identified genes were grouped according to their putative functions; cell/organism defense (9.6%), cell division (5.1%), cell signaling/communication (19.8%), cell structure/motility (12.5%), gene/protein expression (16.9%), metabolism (16.2%), and unclassified (19.8%). Less than 50% of these genes have previously been reported to be expressed in adipose tissue. The chromosomal localization of 268 genes strongly expressed in adipose tissue showed that their relative abundance was significantly increased on chromosomes 11, 19, and 22 compared to the expected distribution of the same number of random genes.

Discussion: Our study resulted in the identification of numerous genes previously not reported to be expressed in adipose tissue. These results suggest that DNA array is a powerful tool in the search for novel regulatory pathways within adipose tissue on a scale that is not possible using conventional methods.
Precision and Accuracy of Dual‐Energy X‐ray Absorptiometry for Determining in Vivo Body Composition of Mice
Authors: Nagy Tim R. , Clair Anne‐Laure
Published: April 2008

Objective: To evaluate the precision and accuracy of dual‐energy X‐ray absorptiometry (DXA) for the measurement of total‐bone mineral density (TBMD), total‐body bone mineral (TBBM), fat mass (FM), and bone‐free lean tissue mass (LTM) in mice.

Research Methods and Procedures: Twenty‐five male C57BL/6J mice (6 to 11 weeks old; 19 to 29 g) were anesthetized and scanned three times (with repositioning between scans) using a peripheral densitometer (Lunar PIXImus). Gravimetric and chemical extraction techniques (Soxhlet) were used as the criterion method for the determination of body composition; ash content was determined by burning at 600°C for 8 hours.

Results: The mean intraindividual coefficients of variation (CV) for the repeated DXA analyses were: TBMD, 0.84%; TBBM, 1.60%; FM, 2.20%; and LTM, 0.86%. Accuracy was determined by comparing the DXA‐derived data from the first scan with the chemical carcass analysis data. DXA accurately measured bone ash content (p = 0.942), underestimated LTM (0.59 ± 0.05g, p < 0.001), and overestimated FM (2.19 ± 0.06g, p < 0.001). Thus, DXA estimated 100% of bone ash content, 97% of carcass LTM, and 209% of carcass FM. DXA‐derived values were then used to predict chemical values of FM and LTM. Chemically extracted FM was best predicted by DXA FM and DXA LTM [FM = −0.50 + 1.09(DXA FM) − 0.11(DXA LTM), model r2 = 0.86, root mean square error (RMSE) = 0.233 g] and chemically determined LTM by DXA LTM [LTM = −0.14 + 1.04(DXA LTM), r2 = 0.99, RMSE = 0.238 g].

Discussion: These data show that the precision of DXA for measuring TBMD, TBBM, FM, and LTM in mice ranges from a low of 0.84% to a high of 2.20% (CV). DXA accurately measured bone ash content but overestimated carcass FM and underestimated LTM. However, because of the close relationship between DXA‐derived data and chemical carcass analysis for FM and LTM, prediction equations can be derived to more accurately predict body composition.
Chronic Intracerebroventricular Administration of Recombinant CART(42–89) Peptide Inhibits Food Intake and Causes Weight Loss in Lean and Obese Zucker (fa/fa) Rats
Authors: Larsen Philip J. , Vrang Niels , Petersen Poul Christian , Kristensen Peter
Published: April 2008

Objective: Hypothalamic neuropeptide CART (cocaineamphetamine‐regulated transcript) is a leptin‐dependent endogenous satiety factor in the rat, and single central injections of recombinant CART(42–89) lowers food intake in rats and mice. To assess the potential role of CART as a long‐term regulator of food intake, we investigated the effects of continuous infusion of recombinant CART(42–89) on food consumption and body weight.

Research Methods and Procedures: Two doses of CART(42–89) were tested: 12 or 4.8 μg/d. Adult male, both lean (+/?) and Zucker (fa/fa) obese, rats were equipped with intracerebroventricular cannulae in the right lateral ventricle. The cannulae were connected to subcutaneously placed osmotic mini‐pumps. Pumps were filled with either CART(42–89) or vehicle (50 mM phosphate‐buffered saline, pH 7.4). The pumps delivered a continuous infusion of CART(42–89) or vehicle, and food intake and body weight were followed for 10 days (12 μg/d) or 7 days (4.8 μg/d). Animals given the low dose had the pump removed on Day 7, and from half of the group, trunk blood was collected after decapitation, whereas the other half of the group had their mini‐pumps removed and were followed for another 7 days before being decapitated.

Results: Animals receiving the high doses displayed overt motor disturbances, whereas the low dose was devoid of such behavioral side effects. Both doses significantly lowered food intake with maximal effect on days 3 to 5 of the infusion period. The high dose of CART decreased body weight of normal animals to 85% of initial weight at days 3 to 5, whereas the weight of Zucker (fa/fa) obese rats dropped to 95% of the initial weight. In animals receiving 4.8 μg/d, moderate effects on body weight were seen between days 4 and 6 of the treatment period, but soon after termination of the treatment animals regained lost weight. To assess the biological activity of the contents of the osmotic mini‐pumps, the pumps were removed from the subcutaneous implantation site, and 5 μL of their contents were injected intracerebroventricularly to naïve animals kept on a restricted feeding schedule. The content of pumps from animals receiving 4.8 μg/d of CART(42–89) potently inhibited food intake, confirming full biological activity despite being kept for 7 days at body temperature.

Discussion: Due to obvious effects on motor behavior, it is impossible with certainty to conclude that the observed effects on feeding and body weight are primary interference with satiety centers or secondary to effects on locomotor pathways. Also, the present experiments suggest that hypothalamic appetite‐regulating neurons are subject to pharmacological desensitization upon prolonged exposure to CART peptide. The underlying mechanism of such desensitization is as yet unknown.
Influence of Body Composition on the Accuracy of Reported Energy Intake in Children
Authors: Fisher Jennifer O. , Johnson Rachel K. , Lindquist Christine , Birch Leann L. , Goran Michael I.
Published: April 2008

Objective: Mis‐reporting dietary intake is a substantial barrier to understanding the role of dietary behavior in disease. Work with adults indicates that heavier individuals under‐report dietary intake and that under‐reporting may be macronutrient‐specific. Whether weight status and macronutrient intake influence the accuracy of dietary reports among children, however, is less clear. This research evaluated children's dietary reporting accuracy as a function of their relative weight, body composition, and macronutrient intake.

Research Methods and Procedures: Participants included 146 4‐ to 11‐year‐old children. Reported energy intake was determined by interviewing children in the presence of parents, using three multiple pass, 24‐hour recalls. Children were classified as having had an under‐reported, accurately reported, or over‐reported dietary intake relative to total energy expenditure, as measured by doubly labeled water. Reporting accuracy was examined as a function of children's body weight, body composition (using dual energy x‐ray absorptiometry), and macronutrient intake.

Results: Average reported intake was, on average, 14% greater than children's estimated expenditure (p < 0.01). Reporting accuracy varied as a function of children's relative weight and body composition; under‐reporting tended to occur among heavier children, having the highest body fat content (p < 0.0001) and relative weight (p < 0.0001).

Discussion: These findings suggest that weight status influences the accuracy of dietary reports made by children and their parents. More research is needed to address possible psychological and social factors that introduce bias in reporting children's dietary data.
Weight Loss, Weight Maintenance, and Improved Cardiovascular Risk Factors after 2 Years Treatment with Orlistat for Obesity
Authors: Rössner Stephan , Sjöström Lars , Noack Rudolf , Meinders A. Edo , Noseda Giorgio ,   on behalf of the European Orlistat Obesity Study
Published: April 2008

Objective: To determine the effect of orlistat, a new lipase inhibitor, on long‐term weight loss, to determine the extent to which orlistat treatment minimizes weight regain in a second year of treatment, and to assess the effects of orlistat on obesity‐related risk factors.

Research Methods and Procedures: This was a 2‐year, multicenter, randomized, double‐blind, placebo‐controlled study. Obese patients (body mass index 28 to 43 kg/m2) were randomized to placebo or orlistat (60 or 120 mg) three times a day, combined with a hypocaloric diet during the first year and a weight maintenance diet in the second year of treatment to prevent weight regain. Changes in body weight, lipid profile, glycemic control, blood pressure, quality of life, safety, and tolerability were measured.

Results: Orlistat‐treated patients lost significantly more weight (p < 0.001) than placebo‐treated patients after Year 1 (6.6%, 8.6%, and 9.7% for the placebo, and orlistat 60 mg and 120 mg groups, respectively). During the second year, orlistat therapy produced less weight regain than placebo (p = 0.005 for orlistat 60 mg; p < 0.001 for orlistat 120 mg). Several obesity‐related risk factors improved significantly more with orlistat treatment than with placebo. Orlistat was generally well tolerated and only 6% of orlistat‐treated patients withdrew because of adverse events. Orlistat leads to predictable gastrointestinal effects related to its mode of action, which were generally mild, transient, and self‐limiting and usually occurred early during treatment.

Discussion: Orlistat administered for 2 years promotes weight loss and minimizes weight regain. Additionally, orlistat therapy improves lipid profile, blood pressure, and quality of life.
Relationship of 30‐Year Changes in Obesity to Sleep‐Disordered Breathing in the Western Collaborative Group Study
Authors: Carmelli Dorit , Swan Gary E. , Bliwise Donald L.
Published: April 2008

Objective: Obesity is an important etiologic factor in sleep‐disordered breathing (SDB), but the extent to which changes in obesity across adult life contribute independently to SDB in old age has not been studied. In this study, we examined the association between changes in obesity from midlife to late adulthood and overnight recording of respiration during sleep.

Research Methods and Procedures: Subjects in this study are from the Western Collaborative Group Study, a longitudinal cardiovascular epidemiological study that began in 1960 through 1961. Overnight sleep recordings were obtained from 281 male participants in the 1995 through 1996 follow‐up of the Western Collaborative Group Study. Subjects were 75 to 91 years old when assessed for SDB as indexed by the respiratory disturbance index and an oxygen desaturation index (O2DI). Long‐term changes in anthropometrics were evaluated and examined in relation to SDB severity.

Results: Over the 30 years of follow‐up, body mass index and waist circumference increased significantly for this sample and were associated with SDB severity as indexed by respiratory disturbance index and O2DI. Waist circumference at baseline and gain in waist circumference over the 30 years of follow‐up (both p = 0.01) were significantly and independently associated with SDB severity as assessed by O2DI. However, percentage of variance as accounted for by waist circumference was modest.

Discussion: This study supports the hypothesis that gain in waist circumference over adult life is significantly associated with SDB severity in older men.
Expressions of Leptin and Insulin‐Like Growth Factor‐I Are Highly Correlated and Region‐Specific in Adipose Tissue of Growing Rats
Authors: Villafuerte Betty C. , Fine Jacqueline B. , Bai Yaohui , Zhao Weidong , Fleming Shea , DiGirolamo Mario
Published: April 2008

Objective: Anatomically distinct adipose tissue regions differ in their predominant modality of growth (i.e., cellular hypertrophy vs. hyperplasia). We examined site‐specific patterns of expression of two genes whose products, leptin and insulin‐like growth factor‐I (IGF‐I), could be involved in mediating differential growth and metabolism of white adipose tissue. We also related these patterns of expression to measures of adipose depot cellularity.

Research Methods and Procedures: Male Wistar rats were fed ad libitum and studied from ages 7 weeks to ∼12 months. Terminal measures of body weights; weights, composition, and cellularity of four white adipose depots; circulating leptin and IGF‐I; and adipose depot‐specific expression levels of leptin and IGF‐I were measured in subsets of rats at 7, 12, 22, 42, and 46 weeks of age.

Results: Both leptin and IGF‐I mRNAs are quantitatively expressed in a depot‐specific manner, in the following order: retroperitoneal ≅ epididymal > mesenteric > subcutaneous inguinal. Furthermore, there is a marked correlation between the expressions of these hormones in the various regions of adipose tissue of rats during the first year of life. The mechanisms that underlie the parallel expressions of leptin and IGF‐I appear to be related to fat‐cell volume.

Discussion: Because both leptin and IGF‐I have been implicated in the regulation of energy homeostasis and are both expressed in adipose tissue, the depot‐specific linkage between the two genes suggests interaction at the autocrine level. This interaction may have an important role in determining functional properties particular to individual adipose depots.
Hypertension and Type 2 Diabetes Comorbidity in Adults in the United States: Risk of Overall and Regional Adiposity
Authors: Okosun Ike S. , Chandra K. M. Dinesh , Choi Simon , Christman Jacqueline , Dever G. E. Alan , Prewitt T. Elaine
Published: April 2008

Objective: To evaluate the impact of generalized, abdominal, and truncal fat deposits on the risk of hypertension and/or diabetes and to determine whether ethnic differences in these fat patterns are independently associated with increased risk for the hypertension–diabetes comorbidity (HDC).

Research Methods and Procedures: Data (n = 7075) from the Third U.S. National Health and Nutrition Examination Survey were used for this investigation. To assess risks of hypertension and/or diabetes that were due to different fat patterns, odds ratios of men and women with various cut‐points of adiposities were compared with normal subjects in logistic regression models, adjusting for age, smoking, and alcohol intake. To evaluate the contribution of ethnic differences in obesity to the risks of HDC, we compared blacks and Hispanics with whites.

Results: Generalized and abdominal obesities were independently associated with increased risk of hypertension, diabetes and HDC in white, black, and Hispanic men and women. The risk of HDC due to generalized, truncal, and abdominal obesities tended to be higher in whites than blacks and Hispanics. In men, the contribution of black and Hispanic ethnicities to the increased risk of HDC due to the various obesity phenotypes was ∼73% and ∼61%, respectively. The corresponding values for black and Hispanic women were ∼115% and ∼125%, respectively.

Conclusions: In addition to advocating behavioral lifestyles to curb the epidemic of obesity among at‐risk populations in the United States, there is also the need for primary health care practitioners to craft their advice to the degree and type of obesity in these at‐risk groups.
Sex Differences in Obese Children and Siblings in Family‐based Obesity Treatment
Authors: Epstein Leonard H. , Paluch Rocco A. , Raynor Hollie A.
Published: April 2008

Objective: The primary goal was to evaluate sex differences in child weight control programs that targeted increasing physical activity (increase) or the combination of reducing sedentary behavior and increasing physical activity (combined). A second goal was to evaluate the benefits of family‐based interventions on nontargeted siblings.

Research Methods and Procedures: Sixty‐seven families with obese children and 89 siblings were randomized to interventions that targeted increasing physical activity (increase) or the combination of reducing sedentary behavior and increasing physical activity (combined). Targeted participants and nontargeted siblings were followed for 1 year.

Results: At 12 months, boys showed significantly better percentages of overweight changes (−15.8%) for the combined treatment than girls (−1.0%), with no significant differences for the increase intervention for boys (−9.3%) or girls (−7.6%). Boys adhered to treatment better than girls (p < 0.01). Adherence and predilection for physical activity were significant predictors of targeted child weight loss at 1 year in multiple regression analysis. Predictors of sibling weight loss included age, number of siblings, targeted child percentage of overweight change, and the interaction of group assignment by same sex of treated sibling.

Discussion: Gender may influence response to programs that attempt to decrease sedentary behavior, and generalization of treatment effects to siblings may depend on the intervention and characteristics of the siblings.
Body Dissatisfaction and Binge Eating in Obese Women: The Role of Restraint and Depression
Authors: Wardle Jane , Waller Jo , Rapoport Lorna
Published: April 2008

Objective: This study examined the association between body dissatisfaction and binge eating, and the mediating role of restraint and depression among obese women.

Research Methods and Procedures: Participants were obese women taking part in a cognitive‐behavioral treatment program who completed self‐report measures at baseline (n = 89) and post‐treatment follow‐up (n = 69).

Results: At baseline, body dissatisfaction was strongly correlated with binge eating score. This was partly a direct effect and partly mediated by depression. No mediating effect of restraint was observed. Over the treatment period, a reduction in body dissatisfaction was associated with a reduction in binge‐eating score. As in the cross‐sectional data, there was evidence for mediation by change in depression with the greatest improvement in binge eating among those who became more restrained and less depressed.

Discussion: These results suggest that it would be valuable to address psychological well‐being, and especially body image, as part of the management of binge‐eating behavior in obesity.
Overeating: The Health Risks
Authors: Prentice Andrew M.
Published: April 2008

Overeating is a relative term. It refers to the consumption of an energy intake that is inappropriately large for a given energy expenditure, thus, leading to obesity. There are several key environmental and cultural factors that have converged in the past few decades to markedly increase the risk of both active and passive (inadvertent) overeating. Chief among these are the increased availability and promotion of cheap energy‐dense diets (usually high in fat) and the transition toward extremely sedentary lifestyles. The importance of considering these factors together must be stressed. Data ranging from highly controlled metabolic studies to large‐scale epidemiological and ecological analysis illustrate the strong interactions between diet and physical activity in relationship to the over‐consumption of energy. Overeating of certain specific dietary components may also lead to health risks. Obvious examples are saturated and trans‐fatty acids. More recently attention has switched to high glycemic foods and to n‐6 fatty acids. Theories that excess consumption of these may be independent risk factors for obesity and ill health remain controversial but merit closer examination and additional research. The main barriers to changing widely prevalent overeating include the following: public and corporate ignorance about the effects of energy‐dense diets in inducing passive over‐consumption, commercial willfulness concerning energy density and portion sizes, and public ignorance about the profound health effects of inactive lifestyles. These represent key targets for the design of public health initiatives.
Obesity‐Related Knowledge, Attitudes, and Behaviors in Obese and Non‐obese Urban Philadelphia Female Adolescents
Authors: Gordon‐Larsen Penny
Published: April 2008

Objectives: To examine relationships between knowledge, attitudinal and behavioral factors, and obesity and to determine how these factors influence obesity status in west Philadelphia female adolescents.

Research Methods and Procedures: A matched‐pairs study was conducted with 32 stature‐ and age‐matched pairs of obese (body mass index and triceps skinfold ≥95th percentile of National Health and Nutrition Examination Survey I) and non‐obese (body mass index and triceps skinfold between the 15th and 85th percentiles of National Health and Nutrition Examination Survey I) female African American adolescents (aged 11 to 15 years), selected from a school‐based study sample, based on obesity status and matching criteria. Adolescents were compared on the following measures: physical activity, inactivity, dietary intake, eating attitudes, health behavior knowledge, body image, self‐esteem, and maturation status. Differences between obese and non‐obese females were tested using paired t tests and Wilcoxon matched‐pairs signed‐rank tests.

Results: Physical activity, inactivity, and perception of ideal body size emerged as the most important contributory factors to obesity status. There were no statistically significant matched‐pair differences in macronutrient and micronutrient intakes, self‐esteem, eating attitudes, health behavior knowledge, or maturation status of these adolescents. Obese adolescents had significantly lower levels of physical activity, higher inactivity, and a larger perception of ideal body size than non‐obese adolescents.

Discussion: Knowledge and attitudinal factors (with the exception of perception of ideal body size) had far less association with obesity than activity‐related behavioral factors. These findings suggest that future intervention strategies should pay particular attention to physical activity, inactivity, and body image attitudes.
Liquid Meal Replacements and Glycemic Control in Obese Type 2 Diabetes Patients
Authors: Yip Ian , Go Vay Liang W , DeShields Scott , Saltsman Pamela , Bellman Mindy , Thames Gail , Murray Shanna , Wang He‐Jing , Elashoff Robert , Heber David
Published: April 2008

Objective: Although weight management is an important component in the treatment of type 2 diabetes, there has been concern about the use of liquid meal replacements (MRs) in treating obese patients with type 2 diabetes because of the sugar content of the MRs. The goal of this study was to evaluate the safety and feasibility of using MRs for weight loss in obese patients with type 2 diabetes.

Research Methods and Procedures: Seventy‐five subjects with type 2 diabetes, treated only with oral agents, were recruited for this 12‐week clinical study. Subjects were randomized into three groups using either a MR containing lactose, fructose, and sucrose, a MR in which fructose and sucrose were replaced with oligosaccharides (sugar‐free Slim‐Fast), or an exchange diet plan (EDP) using the proportion of macronutrients recommended by the American Diabetes Association.

Results: Fifty‐seven patients (41 MR and 16 EDP) finished the study. None developed serious adverse effects, including major hypoglycemic reactions. Weight losses in the MR 1 and MR 2 groups were comparable (6.4% and 6.7%, respectively) and greater than the weight loss in the EDP group (4.9%). Fasting glucose level was significantly reduced in the MR group compared with the EDP group (p = 0.012). There was a significant reduction in the MR group in total cholesterol and low‐density lipoprotein cholesterol that was not seen in the EDP group.

Discussion: We have shown that liquid MRs are a safe and effective weight loss tool for obese subjects with type 2 diabetes, and can result in improvements in body weight, glucose, insulin, hemoglobin A1c and lipid levels.
Conjugated Linoleic Acid (CLA), Body Fat, and Apoptosis*
Authors: Miner Jess L. , Cederberg Chris A. , Nielsen Merlyn K. , Chen Xiaoli , Baile Clifton A.
Published: April 2008

Objective: The objective of the study was to determine if consumption of conjugated linoleic acid (CLA) by mice could induce apoptosis in adipose tissue. Other objectives were to determine the influence of feeding mice CLA for ≤2 weeks on body fat, energy expenditure, and feed intake.

Research Methods and Procedures: A mixture of CLA isomers (predominantly c9,t11 and t10,c12) was included in the AIN‐93G diet at 0, 1, and 2%, and fed to mice for 12 days (Trial 1), or was included at 2% and fed to mice for 0, 5, and 14 days (Trial 2). Feed intake was measured daily and energy expenditure was determined by direct calorimetry on day 9 in Trial 1. Retroperitoneal fat pads were analyzed for apoptosis by determination of DNA fragmentation.

Results: Dietary CLA reduced feed intake by 10% to 12% (p < 0.01), but either did not influence or did not increase energy expenditure as indicated by heat loss. Body weight was not influenced by consumption of CLA in Trial 1 but was increased (p < 0.01) by CLA in Trial 2. Weights of retroperitoneal, epididymal, and brown adipose tissues were lower (p < 0.01) in animals fed CLA, although liver weight was increased (p < 0.10; Trial 1) or not changed (Trial 2). Analysis of retroperitoneal fat pad DNA from both trials indicated that apoptosis was increased (p < 0.01) by CLA consumption.

Discussion: These results are interpreted to indicate that CLA consumption causes apoptosis in white adipose tissue. This effect occurs within 5 days of consuming a diet that contains CLA.
Comparison of Regional Fat Distribution and Health Risk Factors in Middle‐Aged White and African American Women: The Healthy Transitions Study
Authors: Lovejoy Jennifer C. , Smith Steven R. , Rood Jennifer C.
Published: April 2008

Objective: Both ethnicity and menopause appear to influence intra‐abdominal fat distribution. This study evaluated intra‐abdominal fat distribution and obesity‐related health risks in perimenopausal white and African American women.

Research Methods and Procedures: Baseline data from a longitudinal study of changes in body composition and energy balance during menopause are reported. Healthy women (55 African Americans and 103 whites) who were on no medication and had at least five menstrual cycles in the previous 6 months were recruited. Body composition was assessed by DXA, and visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were assessed by computed tomography scan. SAT was divided into deep and superficial layers demarcated by the fascia superficialis.

Results: African American women were slightly younger (46.7 ± 0.2 vs. 47.7 ± 0.2 years, p = 0.002) and fatter (42.4% ± 1.0% vs. 39.4% ± 0.8% body fat, p = 0.02) than white women. In unadjusted data, African Americans had significantly more total abdominal fat and total, deep, and superficial SAT than whites. After adjustment for percent body fat and age, only total and superficial SAT remained significantly higher in African Americans. VAT although slightly less in African American women, did not differ significantly by race. In multiple regression analysis, VAT was the strongest predictor of serum lipids, glucose, and insulin in women of both races, although superficial SAT was significantly associated with fasting glucose in whites.

Conclusions: Middle‐aged African American women have larger SAT depots, adjusted for total body fatness, but do not differ from white women with regard to VAT. The complexity of the relationship between abdominal fat and metabolic risk is increased by ethnic differences in such associations.
Blood Pressure and Pulse Pressure during Long‐Term Weight Loss in the Obese: The Swedish Obese Subjects (SOS) Intervention Study
Authors: Sjöström C. David , Peltonen Markku , Sjöström Lars
Published: April 2008

Objective: Recently we reported a complete relapse in the blood pressure (BP) of obese subjects despite a maintained 16% weight loss over 8 years. This relapse is now analyzed as a function of several variables. Pulse pressure (PP) is an independent risk factor of cardiovascular mortality. We now examine the development of PP in the obese and whether it can be modified by weight‐reducing gastric surgery.

Research Methods and Procedures: A total of 1157 patients treated with gastric surgery and 1031 obese controls (body mass index of 41.0 ± 4.6 kg/m2 [mean ± SD], age 48 ± 6 years) were followed for 5.5 ± 2.1 (range 3 to 10) years. To separate the effect of weight change from effect of time on BP, the patients were divided in cohorts based on follow‐up time.

Results: Gastric surgery resulted in a maximum weight loss after 1 year that was followed by a moderate relapse. After 5.5 years, weight loss in the intervention group was 18 ± 11% of initial body weight. Very little weight change was seen in controls. Systolic BP decreased in the intervention group during the first 6 months but had relapsed to control values at last examination. The adjusted change in PP was +4.7 mm Hg in obese controls but +2.9 mm Hg in the intervention group (p < 0.001). Final BP values were more closely related to follow‐up time and ongoing weight increase than to initial body weight or initial weight loss.

Discussion: Effects of time (aging) and weight change per year on BP can be separated. An early increase in PP could be observed in the obese. This increase could be modified by weight‐reducing gastric surgery.
Anti‐lipolytic Effects of Insulin in African American and White Prepubertal Boys
Authors: Gower Barbara A. , Herd Sara L. , Goran Michael I.
Published: April 2008

Objective: Relative to whites, African Americans have lower circulating triglycerides (TG) and greater highdensity lipoprotein cholesterol. The metabolic basis for this difference is not known. This study was conducted to test the hypothesis that insulin‐induced suppression of free fatty acids (FFA) results in lower serum TG in African American versus white prepubertal children.

Research Methods and Procedures: Insulin, FFA, and TG were determined at baseline and during a frequently sampled, intravenous glucose tolerance test in eight African American and eight white prepubertal males pair‐matched for whole‐body insulin sensitivity.

Results: Baseline TG was lower in African Americans (0.43 ± 0.10 vs. 0.79 ± 0.37 mM/L; mean ± SD; p < 0.01). African Americans had higher peak insulin (218 ± 102 vs. 100 ± 30 pM/L; mean ± SD; p < 0.01) and a greater acute insulin response (9282 ± 4272 vs. 4230 ± 1326 pM/L × 10 minutes; mean ± SD; p < 0.05). FFA and TG values determined at the FFA nadir were lower in African Americans (0.26 ± 0.02 vs. 0.30 ± 0.03 mEq/L; mean ± SD; p < 0.01 for FFA nadir and 0.49 ± 0.07 vs. 0.77 ± 0.33 mM/L; mean ± SD; p < 0.05 for TG). Among all subjects, FFA nadir was correlated with peak insulin (r = −0.54; p < 0.05). After adjusting for FFA nadir, neither baseline nor postchallenge TG differed with ethnicity (p = 0.073 and 0.192, respectively). The ethnic difference in FFA nadir disappeared after adjusting for peak insulin (p = 0.073).

Discussion: These data suggest that hyperinsulinemiainduced suppression of FFA among African Americans is a determinant of lower TG in this group.
Modest Lifestyle Intervention and Glucose Tolerance in Obese African Americans
Authors: Racette Susan B. , Weiss Edward P. , Obert Kathleen A. , Kohrt Wendy M. , Holloszy John O.
Published: April 2008

Objective: Previous studies have demonstrated the benefit of short‐term diets on glucose tolerance in obese individuals. The purpose of this study was to evaluate the effectiveness of modest lifestyle changes in maintaining improvements in glucose tolerance induced by short‐term energy restriction in obese African Americans with impaired glucose tolerance or type 2 diabetes mellitus.

Research Methods and Procedures: An intervention group (n = 45; 47 ± 1 year [mean ± SE]), 105 ± 4 kg; body mass index: 39 ± 1 kg/m2) received an energy‐restricted diet (943 ± 26 kcal/d) for 1 week, followed by a lifestyle program of reduced dietary fat (−125 kcal/d) and increased physical activity (+125 kcal/d) for 1 year. Body weight and plasma concentrations of glucose, insulin, and C‐peptide during an oral glucose tolerance test were measured at baseline, 1‐week, and 4‐month intervals. A control group (n = 24; 48 ± 1 year; 110 ± 5 kg; body mass index: 41 ± 2 kg/m2) underwent these measurements at 4‐month intervals.

Results: No changes in weight or glucose tolerance were observed in the control group. The intervention group had significant (p < 0.05) improvements in body weight and glucose tolerance in response to the 1‐week diet, which persisted for 4 months (p < 0.001 vs. control for change in weight). A total of 19 subjects (42%) continued the intervention program for 1 year, with sustained improvements (weight: −4.6 ± 1.0 kg; p < 0.001 vs. control; oral glucose tolerance test glucose area: −103 ± 44 mM · min; p < 0.05 vs. control).

Discussion: A modest lifestyle program facilitates weight loss and enables improvements in glucose tolerance to be maintained in obese individuals with abnormal glucose tolerance. However, attrition was high, despite the mild nature of the program.
Weight Loss Attempts and Attitudes toward Body Size, Eating, and Physical Activity in American Indian Children: Relationship to Weight Status and Gender
Authors: Story Mary , Stevens June , Evans Marguerite , Cornell Carol E. , Juhaeri  , Gittelsohn Joel , Going Scott B. , Clay Theresa E. , Murray David M.
Published: April 2008

Objective: This study examined dieting, weight perceptions, and self‐efficacy to eat healthy foods and engage in physical activity and their relationships to weight status and gender among American Indian elementary schoolchildren.

Research Methods and Procedures: Data for this study were collected as part of the baseline examination for the Pathways study. Participants were 1441 second‐ through third‐grade American Indian children in 41 schools representing seven tribes in Arizona, New Mexico, and South Dakota who filled out a questionnaire and had heights and weights taken.

Results: Forty‐two percent of the children were overweight or obese. No differences were found between overweight/obese and normal weight children for healthy food intentions or self‐efficacy. Heavier children (especially those with body mass index > 95th percentile) were more likely to have tried to lose weight or were currently trying to lose weight. No gender differences were found. Normal weight children chose a slightly heavier body size as most healthy compared with overweight/obese children.

Discussion: The results indicate that children are concerned about their weight and that weight modification efforts are common among overweight American Indian children. School, community, and family‐based programs are needed to help young people adopt lifelong healthful eating and physical activity practices.
Assessment of Free‐Living Physical Activity in Humans: An Overview of Currently Available and Proposed New Measures
Authors: Schutz Yves , Weinsier Roland L. , Hunter Gary R.
Published: April 2008

The number of physical activity measures and indexes used in the human literature is large and may result in some difficulty for the average investigator to choose the most appropriate measure. Accordingly, this review is intended to provide information on the utility and limitations of the various measures. Its primary focus is the objective assessment of free‐living physical activity in humans based on physiological and biomechanical methods.

The physical activity measures have been classified into three categories:

. Measures based on energy expenditure or oxygen uptake, such as activity energy expenditure, activity‐related time equivalent, physical activity level, physical activity ratio, metabolic equivalent, and a new index of potential interest, daytime physical activity level.

. Measures based on heart rate monitoring, such as net heart rate, physical activity ratio heart rate, physical activity level heart rate, activity‐related time equivalent, and daytime physical activity level heart rate.

. Measures based on whole‐body accelerometry (counts/U time).

Quantification of the velocity and duration of displacement in outdoor conditions by satellites using the Differential Global Positioning System may constitute a surrogate for physical activity, because walking is the primary activity of man in free‐living conditions.

A general outline of the measures and indexes described above is presented in tabular form, along with their respective definition, usual applications, advantages, and shortcomings. A practical example is given with typical values in obese and non‐obese subjects. The various factors to be considered in the selection of physical activity methods include experimental goals, sample size, budget, cultural and social/environmental factors, physical burden for the subject, and statistical factors, such as accuracy and precision.

It is concluded that no single current technique is able to quantify all aspects of physical activity under free‐living conditions, requiring the use of complementary methods. In the future, physical activity sensors, which are of low‐cost, small‐sized, and convenient for subjects, investigators, and clinicians, are needed to reliably monitor, during extended periods in free‐living situations, small changes in movements and grade as well as duration and intensity of typical physical activities.
Larger Amounts of Visceral Adipose Tissue in Asian Americans
Authors: Park Yong‐Woo , Allison David B. , Heymsfield Steven B. , Gallagher Dympna
Published: April 2008

Objective: Excess visceral adipose tissue (VAT) is recognized as an important risk factor for the development of coronary heart disease and type 2 diabetes. Several studies have reported less VAT in African Americans compared with whites. As little is known about the levels of VAT in Asians, we compared whole‐body VAT in Asian Americans with European Americans.

Research Methods and Procedures: VAT was measured using whole‐body multislice magnetic resonance imaging in 54 women (18 Asian Americans, 36 European Americans) and 53 men (19 Asian Americans, 34 European Americans) with body mass index (measured in kilograms per square meter) < 30. Data were analyzed by multiple regression modeling.

Results: Asian American women had higher log‐transformed VAT compared with European American women (p < 0.05), after adjusting for age and total body fat. There was a significant age by race interaction such that race differences in VAT were most evident over the age of 30 years. No differences in VAT could be detected between Asian American and European American men, even after adjusting for potential covariates, including total adiposity. %Discussion: These data are the first to demonstrate higher amounts of VAT in healthy Asian Americans, a finding that suggests normative VAT values or standards derived from whites may not be applicable to Asians.
The Expression of SPARC in Adipose Tissue and Its Increased Plasma Concentration in Patients with Coronary Artery Disease
Authors: Takahashi Masahiko , Nagaretani Hiroyuki , Funahashi Tohru , Nishizawa Hitoshi , Maeda Norikazu , Kishida Ken , Kuriyama Hiroshi , Shimomura Iichiro , Maeda Kazuhisa , Hotta Kikuko , Ouchi Noriyuki , Kihara Shinji , Nakamura Tadashi , Yamashita Shizuya , Matsuzawa Yuji
Published: April 2008

Objective: Adipocytes secrete various cytokines and matrix proteins. Several of them precipitate in obesity‐associated diseases, including atherosclerosis. In the current study, we have examined the expression of secreted protein, acidic and rich in cysteine (SPARC) in adipose tissue and its significance in obesity and coronary artery disease (CAD).

Research Methods and Procedures: The SPARC mRNA expressions both in vivo and in vitro were detected by Northern blot analysis. Plasma SPARC concentrations were measured by enzyme immunosorbent assay. First, we investigated the plasma SPARC levels of 88 unrelated adult Japanese subjects (62 men and 26 women; average age: [± SD] 50 ± 12 years; body mass index [BMI]: 16 to 46 kg/m2). Additionally 31 subjects with CAD diagnosed by coronary angiography (20 men and 11 women) were also investigated.

Results: Human adipose tissues expressed abundant SPARC mRNA. SPARC expression in adipose tissues was upregulated in obese db/db mice. Markedly enhanced expression of SPARC mRNA was observed in 3T3‐L1 fibroblasts during adipocyte differentiation. Consistent with these results, plasma SPARC levels proved a positive correlation with BMI in humans (r = 0.27; p < 0.01). Interestingly, plasma SPARC concentrations were significantly elevated in age‐ and BMI‐matched subjects with CAD (p < 0.05).

Discussion: SPARC was expressed in adipose tissues and its expression was enhanced in obese mice. In human, plasma SPARC levels were elevated in obesity and CAD patients. This elevated SPARC may be involved in the progression of CAD.