bluuebunny/crossref_metadata_2025 huggingface dataset:
Correcting Biases in Estimates of Mortality Attributable to Obesity
Authors: Greenberg James A.
Published: April 2008

Objective:To assess whether a recent study that found a relatively small number of excess deaths attributable to obesity may have underestimated by not correcting for statistical biases.

Research Methods and Procedures:This prospective cohort study used data from the First National Health and Nutrition Examination Survey Epidemiologic Follow‐Up Study. Survival analyses were conducted using 9690 individuals 32 to 87 years of age and 1886 all‐cause deaths during a 9.1‐year follow‐up. Corrections were made for the reputed regression‐dilution bias by using the average BMI during the decade before follow‐up as predictor. Corrections for the reputed reverse‐causation bias were made by excluding participants with a history of serious illness. Attributable fractions were calculated and used to estimate excess deaths.

Results:The uncorrected estimate of excess deaths attributable to obesity (BMI ≥30) was 41.9, using 18.5 to 25 kg/m2as ideal‐weight category. Using average BMI as predictor increased the estimate to 93.3. Correcting for reverse‐causation effects increased the estimate further to 131.1 (range, 93.3 to 169.0). The uncorrected hazard ratio, 1.25, was increased to 1.41 by using average BMI as predictor, and then to 2.40 by correcting for reverse causation. Using BMI 21 to 25 kg/m2and 23 to 25 kg/m2as ideal‐weight categories increased the corrected estimates to 144.6 (range, 80.5 to 177.2) and 164.1 (range, 103.8 to 194.9), respectively. Larger increases were found for overweight and Grade 2 to 4 obesity (BMI ≥35 kg/m2). For overweight, the uncorrected estimate using 18.5 to 25 kg/m2as ideal‐weight category was −88.3 and the corrected estimate using 23 to 25 kg/m2as ideal‐weight category was 205.4 (range, 114.5 to 296.3).

Discussion:Correcting for statistical biases and using higher ideal‐weight categories increased the estimate of excess deaths attributable to obesity by ∼400% and changed the negative estimate for overweight to a large positive estimate.
Prevalence of Metabolic Syndrome and Its Relation to Body Composition in a Chinese Rural Population
Authors: Feng Yan , Hong Xiumei , Li Zhiping , Zhang Wenbin , Jin Delai , Liu Xue , Zhang Yan , Hu Frank B. , Wei Lee‐Jen , Zang Tonghua , Xu Xiping , Xu Xin
Published: April 2008

Objective: To investigate the prevalence of metabolic syndrome (MetS) with three different working definitions in a rural Chinese population and to examine its relation to body composition.

Research Methods and Procedures: A total of 18,630 adults 25 to 64 years old (mean age, 45.8 years; 51.2% men) from 5686 families were enrolled from Anhui province of China during 2004 to 2005. Anthropometric measurement, body composition, blood pressure, plasma lipids, and fasting glucose and insulin and a questionnaire‐based interview were obtained from each participant. Three different working definitions for MetS, including the U.S. National Cholesterol Education Program's Adult Treatment Panel III, a modified Adult Treatment Panel III that adopts the World Health Organization's criterion for central obesity in Asian populations, and one recently proposed by the International Diabetes Federation, were used in the study.

Results: According to the three definitions, the age‐adjusted prevalence of MetS for adults 25 to 64 years old was 3.2%, 4.9%, and 3.9% in men and 7.2%, 11.5%, and 10.9% in women, respectively. MetS prevalence increases significantly with age in women, but not in men. Body fat percentage and BMI and waist circumference were significantly associated with each component of MetS, especially with triglyceride level, insulin resistance index, and number of MetS components (r = 0.28 to 0.49).

Discussion: The age‐adjusted prevalence of MetS in our study population is lower than that reported in other urban Chinese populations. Significant gender differences in MetS prevalence were observed. The waist circumference is a good surrogate for abdominal fat percentage.
Influence of Metabolic Syndrome on Biomarkers of Oxidative Stress and Inflammation in Obese Adults
Authors: Van Guilder Gary P. , Hoetzer Greta L. , Greiner Jared J. , Stauffer Brian L. , DeSouza Christopher A.
Published: April 2008

Objective: Both obesity and the metabolic syndrome (MetS) have been independently linked with increased oxidative and inflammatory stress. This study tested the hypothesis that obesity with MetS is associated with greater oxidative and inflammatory burden compared with obesity alone.

Research Methods and Procedures: Forty‐eight normal‐weight and 40 obese (20 without MetS; 20 with MetS) adults were studied. MetS was defined according to National Cholesterol Education Program Adult Treatment Panel III criteria. Plasma concentrations of oxidized low‐density lipoprotein, C‐reactive protein, tumor necrosis factor‐α, interleukin (IL)‐6, and IL‐18 were determined by enzyme immunoassay.

Results: Plasma biomarkers of oxidative stress and inflammation were lowest in normal‐weight controls. Of note, obese MetS adults demonstrated significantly higher plasma concentrations of oxidized low‐density lipoprotein (62.3 ± 3.2 vs. 54.0 ± 4.0 U/L; p < 0.05), C‐reactive protein (3.0 ± 0.6 vs. 1.5 ± 0.3 mg/L; p < 0.01), tumor necrosis factor‐α (2.1 ± 0.1 vs. 1.6 ± 0.1 pg/mL; p < 0.05), IL‐6 (2.8 ± 0.4 vs. 1.4 ± 0.2 pg/mL; p < 0.01), and IL‐18 (253 ± 16 vs. 199 ± 16 pg/mL; p < 0.01), compared with obese adults without MetS.

Discussion: These results suggest that MetS heightens oxidative stress and inflammatory burden in obese adults. Increased oxidative and inflammatory stress may contribute to the greater risk of coronary heart disease and cerebrovascular disease in obese adults with MetS.
Increase of Neuronal Histamine in Obese Rats Is Associated with Decreases in Body Weight and Plasma Triglycerides
Authors: Malmlöf Kjell , Golozoubova Valeria , Peschke Bernd , Wulff Birgitte S. , Refsgaard Hanne H.F. , Johansen Peter B. , Cremers Thomas , Rimvall Karin
Published: April 2008

Objective:The purpose of the present study was to examine the metabolic effects of a specific histamine H3receptor antagonist, the cinnamic amide NNC 0038‐0000‐1202 (NNC 38‐1202).

Research Methods and Procedures:Effects of NNC 38‐1202 on paraventricular levels of histamine and acute effects on food intake were followed in normal rats, whereas effects on body weight homeostasis and lipid metabolism were studied in a rat model of diet‐induced obesity (DIO).

Results:NNC 38‐1202, administered as single oral doses of 15 and 30 mg/kg, significantly (p< 0.01) increased paraventricular histamine by 339 ± 54% and 403 ± 105%, respectively, compared with basal levels. The same doses produced significant (p< 0.01) reductions in food intake. In DIO rats receiving NNC 38‐1202 in a daily dose of 5 mg/kg for 22 days, a decrease in food intake was associated with a significant (p< 0.001) net loss of body weight (−11.0 ± 4.8 grams), compared with rats receiving vehicle, which gained 13.6 ± 3.0 grams. Also, NNC 38‐1202 significantly (p< 0.05) reduced plasma triglycerides by ∼42%, in parallel with increases in plasma free fatty acids and β‐hydroxybutyrate levels. Despite reductions in food intake and body weight following administration of NNC 38‐1202, no sign of a decrease in energy expenditure was observed, and whole‐body lipid oxidation was significantly (p< 0.05) increased in the period after dosing.

Discussion:The present study suggests that antagonistic targeting of the histamine H3receptor decreases food intake, body weight, and plasma TG levels and, thus, represents an interesting approach to treatment of obesity and associated hyperlipidemia.
Comparison of Metabolic Risk Factors between Severely and Very Severely Obese Patients
Authors: Wolf Anna M. , Buffington Cynthia , Beisiegel Ulrike
Published: April 2008

Objective: A prospective clinical intervention study was performed to estimate the metabolic risk factors in patients with very severe obesity (VSO) vs. severe obesity (SO).

Research Methods and Procedures: Two hundred twenty‐eight VSO (BMI ≥ 50 kg/m2) and 221 SO patients (BMI = 40 to 49.9 kg/m2) participated in the study (367 women and 82 men). Metabolic measurements included plasma lipids, glucose and insulin, hemoglobin A1c, leptin, and sex hormones, as well as hepatic steatosis in a subgroup of patients. Subgroups of patients with non–insulin‐dependent diabetes and hyperlipidemia (HLP) were examined.

Results: The most unexpected result of our study was that VSO men showed significantly better lipid profiles than SO men. Furthermore, 18% of VSO men had no metabolic aberrations, whereas all SO men did. The advantageous metabolic status of VSO men was associated with sex hormone changes that favor gynoid fat distribution. The beneficial metabolic situation with VSO seems to be sex specific for men.

Discussion: This study shows that the metabolic situation in VSO is not more severe than in the less obese cohort. These findings distinctly differ from the positive associations that have previously been reported between BMI, lipids, and other metabolic indices among individuals whose BMI is <40 kg/m2.
A Workplace Intervention to Promote Stair Climbing: Greater Effects in the Overweight
Authors: Eves Frank F. , Webb Oliver J. , Mutrie Nanette
Published: April 2008

Objective: Stair climbing is a lifestyle physical activity that uses more calories per minute than jogging. This study tested an intervention designed to promote stair climbing in a workplace. Because previous studies provide only equivocal evidence of the effects of increased stair climbing in worksites, a formal comparison of the effects of the intervention on stair ascent and descent was made.

Research Methods and Procedures: In a five‐story public sector building, a 2‐week baseline was followed by 6 weeks of an intervention involving a 23½‐ × 16½‐inch poster in the lobby, the same poster and six messages affixed to the stair risers between floors, and an 11¾‐ × 8¼‐inch point‐of‐choice prompt at the elevators. Stair and elevator choices (n = 26,806) were videotaped throughout and subsequently coded for direction of travel, traveler's sex, and traveler's load. Weight status was coded using silhouettes beside the computer monitor.

Results: A significant effect of the intervention on stair climbing was greater in those coded as overweight (+5.4%; odds ratio = 1.33) than in individuals of normal weight (+2.5%; odds ratio = 1.12). Although stair descent was more common than ascent, the intervention had similar effects for both directions of travel.

Discussion: Stair climbing at work has few barriers and seems to be a type of physical activity that is acceptable to overweight individuals. The relatively weak effect of workplace interventions compared with results for public access staircases may reflect uncontrolled effects such as the immediate availability of the elevator for the traveler.
Physical Activity Compliance: Differences between Overweight/Obese and Normal‐Weight Adults
Authors: Davis Jaimie N. , Hodges Valerie A. , Gillham M. Beth
Published: April 2008

Objectives: Comparisons of physical activity measured by accelerometers in overweight/obese adults and their normal‐weight counterparts are limited. Compliance with the 2002 Institute of Medicine (IOM) exercise recommendations for 60 minutes of moderate‐intensity exercise daily has not been reported. The purpose of this study was to compare physical activity, as measured by accelerometers, in overweight/obese adults vs. normal‐weight controls and to assess compliance with recommendations for physical activity by the IOM in 2002 and by the Centers for Disease Control and Prevention and American College of Sports Medicine in 1995 for 30 minutes of moderate‐intensity activity, preferably all days of the week.

Research Methods and Procedures: Sixty‐two overweight/obese subjects, BMI ≥ 25, included 31 adults, 12 men and 19 women, 25 to 69 years old, and their normal‐weight controls, BMI 18.5 to 24.9, matched for gender, age, and height. Body composition was assessed using DXA. Physical activity was measured with Actigraph accelerometers (MTI, Fort Walton Beach, FL) worn by each participant for 7 consecutive days.

Results: Accelerometry data indicated that overweight/obese adults recorded ∼60 counts per minute less per day and spent 21 minutes less engaged in moderate or greater intensity activity than their normal‐weight counterparts. Although 71% to 94% of those studied met 1995 recommendations, only 13% of overweight/obese subjects and 26% of normal‐weight participants met 2002 exercise recommendations.

Discussion: These results suggest that daily minutes spent in moderate‐intensity activity or greater are associated with weight status and that the 2002 IOM recommendations may be difficult to meet even for normal‐weight individuals.
Smoking during Pregnancy and Offspring Fat and Lean Mass in Childhood
Authors: Leary Sam D. , Smith George Davey , Rogers Imogen S. , Reilly John J. , Wells Jonathan C.K. , Ness Andy R.
Published: April 2008

Objective: Maternal smoking during pregnancy has been shown to be associated with obesity in the offspring, but findings have been based mainly on BMI, which is derived from height and weight. This study examined the association between maternal and partner smoking during pregnancy and offspring total fat, truncal fat, and lean mass in childhood.

Research Methods and Procedures: Analysis was based on 5689 white singletons born in 1991–1992 and enrolled in the Avon Longitudinal Study of Parents and Children, with maternal smoking data recorded for at least one trimester in pregnancy and their own body composition assessed by DXA at mean age 9.9 years.

Results: Smoking at any time during pregnancy was associated with higher offspring BMI [0.18 (95% confidence interval, 0.12 to 0.25) standard deviation units] and total fat mass [0.17 (95% confidence interval, 0.12 to 0.23) standard deviation units], after adjustment for age, sex, height, and height squared for total fat mass. These associations were not attenuated by adjustment for the confounding factors that were measured. Maternal smoking was also associated with lean mass and, to a lesser extent, truncal fat mass. Associations with partner's smoking were in the same direction but weaker than those of the mother's for all outcomes.

Discussion: Maternal smoking at any time during pregnancy is associated with higher offspring total fat mass at mean age 9.9 years. However, as the associations with partner smoking were only a little weaker than those with maternal smoking, confounding by social factors rather than a direct effect of maternal smoking is a possible explanation.
Is Visceral Fat Involved in the Pathogenesis of the Metabolic Syndrome? Human Model
Authors: Jensen Michael D.
Published: April 2008

Objective: To review the evidence for and against the role of visceral adipose tissue as a major contributor to the metabolic complications of obesity through abnormal regulation of lipolysis.

Research Methods and Procedures: Data from investigators in the field who have studied visceral adiposity and metabolic health and/or regional and systemic free fatty acid (FFA) release were considered.

Results: Although visceral fat mass was positively correlated with adverse health consequences and excess FFA availability, visceral fat was not the source of excess systemic FFA availability. Upper body non‐visceral fat contributes the majority of FFAs in lean, obese, diabetic, and non‐diabetic humans. Increasing amounts of visceral fat probably result in greater hepatic FFA delivery.

Discussion: Systemic, as opposed to hepatic, insulin resistance is unlikely to be caused by high rates of visceral adipose tissue lipolysis.
Metabolic Syndrome: Adenosine Monophosphate‐activated Protein Kinase and Malonyl Coenzyme A
Authors: Ruderman Neil B. , Saha Asish K.
Published: April 2008

The metabolic syndrome can be defined as a state of metabolic dysregulation characterized by insulin resistance, central obesity, and a predisposition to type 2 diabetes, dyslipidemia, premature atherosclerosis, and other diseases. An increasing body of evidence has linked the metabolic syndrome to abnormalities in lipid metabolism that ultimately lead to cellular dysfunction. We review here the hypothesis that, in many instances, the cause of these lipid abnormalities could be a dysregulation of the adenosine monophosphate‐activated protein kinase (AMPK)/malonyl coenzyme A (CoA) fuel‐sensing and signaling mechanism. Such dysregulation could be reflected by isolated increases in malonyl CoA or by concurrent changes in malonyl CoA and AMPK, both of which would alter intracellular fatty acid partitioning. The possibility is also raised that pharmacological agents and other factors that activate AMPK and/or decrease malonyl CoA could be therapeutic targets.
Night Eating Syndrome and Binge Eating Disorder among Persons Seeking Bariatric Surgery: Prevalence and Related Features
Authors: Allison Kelly C. , Wadden Thomas A. , Sarwer David B. , Fabricatore Anthony N. , Crerand Canice E. , Gibbons Lauren M. , Stack Rebecca M. , Stunkard Albert J. , Williams Noel N.
Published: April 2008

Objective: To assess the prevalence of night eating syndrome (NES) and binge eating disorder (BED) and their related behavioral and psychological correlates in persons who sought bariatric surgery.

Research Methods and Procedures: A consecutive series of 215 persons with extreme obesity (82% women, 70% European American) completed the Weight and Lifestyle Inventory and a semistructured interview as part of a pre‐surgery behavioral/psychological assessment. Diagnoses for NES and BED were based on graded diagnostic criteria.

Results: Percentages of participants who met diagnostic criteria for NES by interview were 1.9% for the strictest definition and 8.9% across all definitions of NES. After interview, full DSM‐TR criteria for BED were met by 4.2%; an additional 1.4% reported binge eating at least once per week. Self‐reported prevalence of NES and BED were higher. Those with NES or BED had significantly more symptoms of depression and a greater history of psychological complications than the remaining sample.

Discussion: The prevalence rates of NES and BED among this population of bariatric surgery candidates were lower than expected based on previous reports. Findings and hypotheses regarding lowered prevalence rates are discussed.
Perspective on the Central Control of Appetite
Authors: Blundell John E.
Published: April 2008

BLUNDELL, JOHN E. Perspective on the central control of appetite.
Orosensory Considerations
Authors: Mattes Richard D.
Published: April 2008

MATTES, RICHARD D. Orosensory considerations.
Interleukin‐6 g.−174G>C Promoter Polymorphism Is Associated with Obesity in the EPIC‐Potsdam Study
Authors: Klipstein‐Grobusch Kerstin , Möhlig Matthias , Spranger Joachim , Hoffmann Kurt , Rodrigues Fabio U.S. , Sharma Arya M. , Klaus Susanne , Pfeiffer Andreas F.H. , Boeing Heiner
Published: April 2008

Homozygosity for the interleukin‐6 (IL‐6) g.−174G>C promoter polymorphism has recently been associated with indices of overweight. Homozygous subjects were observed to have reduced energy expenditure, suggesting that lower IL‐6 gene transcription, caused by the IL‐6 g.−174G>C promoter polymorphism, may be associated with obesity. The aim of this study was to investigate the association of this polymorphism with long‐term weight gain. For 334 normal weight (20 < BMI ≤ 25 kg/m2) and 334 obese (BMI > 30 kg/m2) subjects matched by age and sex originating from the population‐based EPIC‐Potsdam Study, recalled weight change from age 25 to study enrollment was determined, the IL‐6 g.–174G>C promoter polymorphism was defined, and plasma concentrations of IL‐6 and C‐reactive protein were measured. The IL‐6 g.−174G>C promoter polymorphism was significantly associated with obesity (χ2 = 7, 34, p = 0.026). Odds ratios for subjects with GC and CC genotypes for obesity were 1.19 (95% CI: 0.84 to 1.68; p = 0.323) and 1.91 (95% CI: 1.19 to 3.08; p = 0.007), respectively. Recalled weight change from age 25 years to study enrollment differed significantly according to genotype (p = 0.044) and was most pronounced in subjects with the CC genotype, suggesting that the IL‐6 g.−174G>C promoter polymorphism is a susceptibility or modifying locus for common obesity and weight gain.
Sex Difference in the Relationship between the Hypothalamic‐pituitary‐adrenal Axis and Sex Hormones in Obesity
Authors: Vicennati Valentina , Ceroni Luana , Genghini Silvia , Patton Laura , Pagotto Uberto , Pasquali Renato
Published: April 2008

Objective: This study was carried out to investigate the role of sex in the regulation of the hypothalamic‐pituitary‐adrenal (HPA) axis and its relationship with testosterone levels in male and female obesity.

Research Methods and Procedures: Twenty‐two obese men (OB‐M) and 29 obese women (OB‐W) participated in the study. Two groups of normal weight men (NW‐M) and women (NW‐W), respectively, served as controls. In basal conditions, blood concentrations of major androgens, sex hormone—binding protein, and gonadotropins were assessed, and the free androgen index (testosterone ×100/ sex hormone‐binding globulin) was calculated. All subjects underwent a combined corticotropin‐releasing hormone plus arginine‐vasopressin stimulation test.

Results: OB‐M and NW‐M had higher basal adrenal cortical tropic hormone (ACTH) and cortisol levels than their female counterparts. In addition, ACTH, but not cortisol basal, levels were significantly higher in obese than in normal weight controls in both sexes. OB‐W had a higher response than OB‐M to the combined corticotropin‐releasing hormone plus arginine‐vasopressin test of both ACTH and cortisol [expressed as incremental percentage of area under the curve (AUC%)]. The same finding was present between NW‐W and NW‐M. Basal luteinizing hormone levels were negatively correlated to ACTHAUC% in both OB‐W and OB‐M. In the OB‐W, however, a positive correlation was found between cortisolAUC% and testosterone (r = 0.48; p = 0.002), whereas a tendency toward a negative correlation was present in OB‐M.

Discussion: In conclusion, we have shown a significant positive relationship between the activity of the HPA axis and testosterone in obese women, which suggests a partial responsibility of increased HPA axis activity in determining testosterone levels. In addition, it clearly seems that, as reported in normal weight subjects, a sex difference in the HPA axis activity still persists even in the presence of obesity.
Cholecystokinin and Treatment of Meal Size: Proof of Principle
Authors: Smith Gerard P.
Published: April 2008

SMITH, GERARD P. Cholecystokinin and treatment of meal size: proof of principle.
Clinical Implications for the Treatment of Obesity
Authors: Foster Gary D.
Published: April 2008

FOSTER, GARY D. Clinical implications for the treatment of obesity.
Central Regulation of Energy Homeostasis Intelligent Design: How to Build the Perfect Survivor
Authors: Levin Barry E.
Published: April 2008

The perfect survivor must be able to eat and store as many calories as possible when food is readily available as a buffer against periods of scarcity. He must also reduce energy expenditure when food is scarce and efficiently and accurately restore lost adipose stores when food is again available. These processes are dependent on information relayed to a distributed central network of metabolic sensing neurons through hard‐wired neural, metabolic, and hormonal signals from the periphery. These sensing neurons engage neuroendocrine, autonomic, and motor processes involved in arousal, motor activity, and the ingestion, absorption, assimilation, storage, and expenditure of calories. A raised threshold in these metabolic sensors for detecting inhibitory signals from increasing adipose stores allows continued intake of excess calories when they are readily available. Unfortunately, this mechanism for surviving periods of feast and famine predisposes the perfect survivor to become obese when highly palatable, energy dense foods are readily available at low energetic cost. It further assures that raised adipose stores are metabolically defended against attempts to lower them. Thus, effective treatment of obesity will only come with a better understanding of the physiological, metabolic, and neurochemical processes that ensure this defense of an elevated body weight.
Homeostatic and Non‐homeostatic Pathways Involved in the Control of Food Intake and Energy Balance
Authors: Berthoud Hans‐Rudolf
Published: April 2008

A neural network sensitive to leptin and other energy status signals stretching from the hypothalamus to the caudal medulla has been identified as the homeostatic control system for the regulation of food intake and energy balance. While this system is remarkably powerful in defending the lower limits of adiposity, it is weak in curbing appetite in a world of plenty. Another extensive neural system that processes appetitive and rewarding aspects of food intake is mainly interacting with the external world. This non‐homeostatic system is constantly attacked by sophisticated signals from the environment, ultimately resulting in increased energy intake in many genetically predisposed individuals. Recent findings suggest a role for accumbens–hypothalamic pathways in the interaction between non‐homeostatic and homeostatic factors that control food intake. Identification of the neural pathways that mediate this dominance of cortico‐limbic processes over the homeostatic regulatory circuits in the hypothalamus and brainstem will be important for the development of behavioral strategies and pharmacological therapies in the fight against obesity.
Genetic Dissection of Neuronal Pathways Controlling Energy Homeostasis
Authors: Balthasar Nina
Published: April 2008

Recent research has identified a number of genes playing critical roles in the central regulation of energy homeostasis. Subsequently, models of the neurocircuitry regulating energy balance have been suggested, although their physiological relevance remains mostly untested. Using the Cre/loxP system, we can now genetically dissect these neurocircuits and establish the specific roles of these genes in small neuronal subpopulations. Here we focus on two receptors shown to be critical in the central regulation of energy homeostasis: leptin (LepR) and melanocortin‐4 receptors (MC4R). Mice and humans deficient in either leptin or melanocortin signaling are severely obese. A prominent model of leptin action places the arcuate nucleus of the hypothalamus, and in particular arcuate proopiomelanocortin (POMC) neurons, at the center stage of energy balance regulation. By deleting LepR specifically from POMC neurons in mice, we showed that LepR on POMC neurons are required but not solely responsible for leptin's regulation of body weight homeostasis. Thus, LepR on other neurons must also be critically important in leptin‐mediated regulation of body weight homeostasis. Data from MC4R‐deficient mice have shown that MC4Rs regulate both sides of the energy intake/energy expenditure balance. Our recent experiments used MC4R‐deficient mice with restored MC4R expression only in the paraventricular hypothalamus and a subpopulation of amygdala neurons. We showed that MC4Rs in the paraventricular hypothalamus and/or amygdala are sufficient to control food intake but that MC4Rs elsewhere control energy expenditure, thereby discovering the novel concept of functional and anatomical divergence of MC4Rs.
Validity of Hand‐to‐Foot Measurement of Bioimpedance: Standing Compared with Lying Position
Authors: Rush Elaine C. , Crowley Jennifer , Freitas Ismael F. , Luke Amy
Published: April 2008

Objective: To assess the reliability of the standing measurement of hand‐to‐foot bioimpedance compared with measurements made in the lying position.

Research Methods and Procedures: In 205 volunteers 6 to 89 years of age, 111 males and 94 females from six ethnic groups, effects of posture, time, and age on hand‐to‐foot resistance were studied over a range of body size. The effect of time in a position on resistance was also recorded in a small subset (n = 10), and repeat measurements over 3 days at the same time of the day were recorded in another subset (n = 12).

Results: Lying impedance was consistently higher than standing, with the relationship (resistance lying/resistance standing) for the children (5 to 14 years) being 1.031, progressing to a ratio of 1.016 in those >60 years. The time spent static in either position did change resistance measurements—a decrease of up to 9 Ω (mean 5 Ω, 1.0%) over 10 minutes of standing and an increase of up to 7 Ω (mean 3 Ω, 0.7%) with lying.

Discussion: In the field, measurements of hand‐to‐foot bioimpedance can be made in the standing position, and, with appropriate adjustment, previously validated recumbent equations can be used. Given that errors in the measurement of height and weight also affect the reliability of the derivation of body fat from bioelectrical conductance, the errors that may arise from a more practical standing measurement rather than lying are minimal.
Web‐based Weight Management Programs in an Integrated Health Care Setting: A Randomized, Controlled Trial
Authors: Rothert Kendra , Strecher Victor J. , Doyle Laurie A. , Caplan William M. , Joyce Jodi S. , Jimison Holly B. , Karm Lya M. , Mims Adrienne D. , Roth Mark A.
Published: April 2008

Objective: To assess the efficacy of a Web‐based tailored behavioral weight management program compared with Web‐based information‐only weight management materials.

Research Methods and Procedures: Participants, 2862 eligible overweight and obese (BMI = 27 to 40 kg/m2) members from four regions of Kaiser Permanente's integrated health care delivery system, were randomized to receive either a tailored expert system or information‐only Web‐based weight management materials. Weight change and program satisfaction were assessed by self‐report through an Internet‐based survey at 3‐ and 6‐month follow‐up periods.

Results: Significantly greater weight loss at follow‐up was found among participants assigned to the tailored expert system than among those assigned to the information‐only condition. Subjects in the tailored expert system lost a mean of 3 ± 0.3% of their baseline weight, whereas subjects in the information‐only condition lost a mean of 1.2 ± 0.4% (p < 0.0004). Participants were also more likely to report that the tailored expert system was personally relevant, helpful, and easy to understand. Notably, 36% of enrollees were African‐American, with enrollment rates higher than the general proportion of African Americans in any of the study regions.

Discussion: The results of this large, randomized control trial show the potential benefit of the Web‐based tailored expert system for weight management compared with a Web‐based information‐only weight management program.
Increased Exercise Capacity after Surgically Induced Weight Loss in Morbid Obesity
Authors: Serés Luis , Lopez‐Ayerbe Jordi , Coll Ramón , Rodriguez Oriol , Vila Juan , Formiguera Xavier , Alastrue Antonio , Rull Miguel , Valle Vicente
Published: April 2008

Objective: To investigate the effects of surgically induced weight loss on exercise capacity in patients with morbid obesity (MO).

Research Methods and Procedures: A prospective 1‐year follow‐up study was carried out, with patients being their own controls. A symptom‐limited cardiopulmonary exercise stress test was performed in 31 MO patients (BMI > 40 kg/m2) before and 1 year after undergoing bariatric surgery.

Results: At 1 year after surgery, weight was reduced from 146 ± 33 to 95 ± 19 kg (p < 0.001), and BMI went from 51 ± 4 to 33 ± 6 kg/m2 (p < 0.001). After weight loss, obese patients performed each workload with lower oxygen consumption, heart rate, systolic arterial pressure, and ventilatory volume (p < 0.001). This reduced energy expenditure allowed them to increase the duration of their effort test from 13.8 ± 3.8 to 21 ± 4.2 minutes (p < 0.001). Upon finishing the exercise, MO patients before surgery were able to reach only 83% of their age‐predicted maximal heart rate, and their respiratory exchange ratio was 0.87 ± 0.06. After weight loss, those values were 90% and 1 ± 0.08, respectively (p < 0.01). When we compared the peak O2 pulse corrected by fat free mass before and after surgery, no significant differences between the groups were found.

Discussion: After surgically induced weight loss, MO patients markedly improved their exercise capacity. This is due to the fact that they were able to perform the external work with lower energy expenditure and also to increase cardiovascular stress, optimizing the use of cardiac reserve. There were no differences in cardiac function before and after surgery.
Neurobiology of Exercise
Authors: Dishman Rod K. , Berthoud Hans‐Rudolf , Booth Frank W. , Cotman Carl W. , Edgerton V. Reggie , Fleshner Monika R. , Gandevia Simon C. , Gomez‐Pinilla Fernando , Greenwood Benjamin N. , Hillman Charles H. , Kramer Arthur F. , Levin Barry E. , Moran Timothy H. , Russo‐Neustadt Amelia A. , Salamone John D. , van Hoomissen Jacqueline D. , Wade Charles E. , York David A. , Zigmond Michael J.
Published: April 2008

Voluntary physical activity and exercise training can favorably influence brain plasticity by facilitating neurogenerative, neuroadaptive, and neuroprotective processes. At least some of the processes are mediated by neurotrophic factors. Motor skill training and regular exercise enhance executive functions of cognition and some types of learning, including motor learning in the spinal cord. These adaptations in the central nervous system have implications for the prevention and treatment of obesity, cancer, depression, the decline in cognition associated with aging, and neurological disorders such as Parkinson's disease, Alzheimer's dementia, ischemic stroke, and head and spinal cord injury. Chronic voluntary physical activity also attenuates neural responses to stress in brain circuits responsible for regulating peripheral sympathetic activity, suggesting constraint on sympathetic responses to stress that could plausibly contribute to reductions in clinical disorders such as hypertension, heart failure, oxidative stress, and suppression of immunity. Mechanisms explaining these adaptations are not as yet known, but metabolic and neurochemical pathways among skeletal muscle, the spinal cord, and the brain offer plausible, testable mechanisms that might help explain effects of physical activity and exercise on the central nervous system.
Adiponectin Receptors in Human Adipose Tissue: Effects of Obesity, Weight Loss, and Fat Depots
Authors: Rasmussen Maria S. , Lihn Aina S. , Pedersen Steen B. , Bruun Jens M. , Rasmussen Mads , Richelsen Bjørn
Published: April 2008

Objective: To investigate the presence and regulatory properties of the adiponectin receptors, AdipoR1 and AdipoR2, in human adipose tissue (AT) and in isolated human adipocytes.

Research Methods and Procedures: The effect of obesity, weight loss, and gender on expression of AdipoR1 and AdipoR2 was investigated in subcutaneous AT. The influence of fat distribution on these receptors was investigated in paired samples of subcutaneous and omental AT. Gene expression of these receptors was quantified by reverse transcriptase‐polymerase chain reaction.

Results: AdipoR1 mRNA levels were ∼10‐fold higher than adipoR2 in both AT fragments and in isolated adipocytes. AdipoR1 expression was lower in AT from obese subjects (p < 0.05) compared with that from normal‐weight subjects, and AdipoR1 displayed a negative correlation with BMI (r = −0.53, p < 0.01). In obese subjects, weight loss (∼12 kg) increased AdipoR1 expression by 80% in AT (p < 0.01). Concerning regional differences, AdipoR1 showed significantly lower expression in omental AT than in subcutaneous AT (p < 0.01). No gender difference was observed in the expression of these receptors. In human preadipocyte cultures, AdipoR1 expression was not induced during the differentiation process, whereas AdipoR2 was induced by 5‐fold (p < 0.05).

Discussion: AdipoR1 is highly expressed in human AT, indicating that adiponectin may have biological effects in AT in an autocrine/paracrine manner. AdipoR1 expression in AT is reduced in obese subjects and is increased after weight loss. Thus, it can be suggested that adiponectin might have reduced biological effects in AT due to low levels of adiponectin receptors in obese subjects and in omental adipocytes, which may further aggravate the negative metabolic effect of low levels of adiponectin characterizing the obese state.
The Influence of One's Own Body Weight on Implicit and Explicit Anti‐fat Bias
Authors: Schwartz Marlene B. , Vartanian Lenny R. , Nosek Brian A. , Brownell Kelly D.
Published: April 2008

Objective: This study examined the influence of one's own body weight on the strength of implicit and explicit anti‐fat bias.

Research Methods and Procedure: Implicit and explicit anti‐fat attitudes and obesity stereotypes were assessed among a large online sample (N = 4283) that included representation from across the weight spectrum (from underweight to extremely obese). Respondents also indicated their willingness to make a range of personal sacrifices in exchange for not being obese.

Results: All weight groups exhibited significant anti‐fat bias, but there was an inverse relation between one's own weight and the level of observed bias. Thinner people were more likely to automatically associate negative attributes (bad, lazy) with fat people, to prefer thin people to fat people, and to explicitly rate fat people as lazier and less motivated than thin people. However, when the lazy stereotype was contrasted with another negative attribute (anxious), obese and non‐obese people exhibited equally strong implicit stereotyping. Finally, a substantial proportion of respondents indicated a willingness to endure aversive life events to avoid being obese. For example, 46% of the total sample indicated that they would rather give up 1 year of life than be obese, and 30% reported that they would rather be divorced than be obese. In each case, thinner people were more willing to sacrifice aspects of their health or life circumstances than were heavier people.

Discussion: Although the strength of weight bias decreased as respondents’ body weight increased, a significant degree of anti‐fat bias was still evident among even the most obese group of respondents, highlighting the pervasiveness of this bias.
The Perceived Effectiveness of Continuing Care and Group Support in the Long‐Term Self‐Help Treatment of Obesity
Authors: Latner Janet D. , Stunkard Albert J. , Wilson G. Terence , Jackson Mary L.
Published: April 2008

Objective: Obesity is increasingly considered a chronic disease requiring continuing care, but professional long‐term treatment for most patients is not available. This study examined treatment recipients’ perception of the effectiveness of different components of a group self‐help, continuing‐care treatment program for obesity.

Research Methods and Procedures: Members (n = 120) and volunteer leaders (n = 66) of a self‐help, continuing‐care treatment program of previously demonstrated effectiveness (mean treatment duration, 40.6 months; mean weight lost, 14.1 kg) rated how helpful and effective they found the various therapeutic strategies used by this program. The strategies examined were continuing care, group support, behavior therapy, motivational enhancement strategies involving positive reinforcement, and motivational enhancement strategies involving punishment.

Results: The single most highly valued aspect of treatment was the provision of continuing care, followed by group support. Greater success at achieving one's goal weight was associated with perceptions of greater effectiveness of the program's strategies overall (r = 0.219, p < 0.005), of continuing care (r = 0.225, p < 0.005), and of positive reinforcement strategies (r = 0.223, p < 0.01). Participants who had successfully attained their goal weight perceived behavior therapy strategies as more effective than did participants who had not reached their goal weight [t (170) = 2.93, p < 0.005].

Discussion: The high ratings given to continuing care and group support strategies indicate the acceptability of supportive self‐help treatment for obesity administered over the long term. The findings suggest that continuing care and group support should be made available to participants in the self‐help treatment of obesity.
Obesity and Sexual Quality of Life
Authors: Kolotkin Ronette L. , Binks Martin , Crosby Ross D. , Østbye Truls , Gress Richard E. , Adams Ted D.
Published: April 2008

Objectives: Reduced sexual quality of life is a frequently reported yet rarely studied consequence of obesity. The objectives of this study were to 1) examine the prevalence of sexual quality‐of‐life difficulties in obese individuals and 2) investigate the association between sexual quality of life and BMI class, sex, and obesity treatment—seeking status.

Research Methods and Procedures: Subjects consisted of 1) 500 participants in an intensive residential program for weight loss and lifestyle modification (BMI = 41.3 kg/m2), 2) 372 patients evaluated for gastric bypass surgery (BMI = 47.1 kg/m2), and 3) 286 obese control subjects not seeking weight loss treatment (BMI = 43.6 kg/m2). Participants completed the Impact of Weight on Quality of Life‐Lite, a measure of weight‐related quality of life. Responses to the four Sexual Life items (assessing enjoyment, desire, performance, and avoidance) were analyzed by BMI, sex, and group.

Results: Higher BMI was associated with greater impairments in sexual quality of life. Obese women reported more impairment in sexual quality of life than obese men for three of four items. Gastric bypass surgery candidates reported more impairment in sexual quality of life than residential patients and controls for most items. In general, residential patients reported levels of impairment greater than or equal to controls.

Discussion: Obesity is associated with lack of enjoyment of sexual activity, lack of sexual desire, difficulties with sexual performance, and avoidance of sexual encounters. Sexual quality of life is most impaired for women, individuals with Class III obesity, and patients seeking gastric bypass surgery.
Chronic Dietary Vitamin A Supplementation Regulates Obesity in an Obese Mutant WNIN/Ob Rat Model
Authors: Jeyakumar Shanmugam M. , Vajreswari Ayyalasomayajula , Giridharan Nappan V.
Published: April 2008

Objective: To understand the possible role of chronic dietary high vitamin A supplementation in body weight regulation and obesity using a novel WNIN/Ob obese rat model developed at the National Centre for Laboratory Animal Sciences of National Institute of Nutrition, India.

Research Methods and Procedures: Thirty‐six 7‐month‐old male rats of lean, carrier, and obese phenotypes were broadly divided into two groups; each group was subdivided into three subgroups consisting of six lean, six carrier, and six obese rats and received diets containing either 2.6 or 129 mg vitamin A/kg of diet for 2 months. Body weight gain, food intake, and weights of various organs were recorded. Adiposity index and BMI were calculated. Serum and liver retinol and brown adipose tissue (BAT)‐uncoupling protein1 (UCP1) mRNA expression levels were quantified.

Results: Chronic feeding of high but non‐toxic doses of vitamin A through diet significantly reduced (P ≤ 0.05) body weight gain, adiposity index, and retroperitoneal white adipose tissue mass (without affecting food intake) in obese rats compared with their lean and carrier counterparts. In general, vitamin A treatment significantly improved hepatic retinol stores (P ≤ 0.05) in all phenotypes without affecting serum free retinol levels. However, augmented BAT‐UCP1 expression was observed only in carrier and obese rats (whose basal expression was low).

Discussion: Our data suggest that chronic dietary vitamin A supplementation at high doses effectively regulates obesity in obese phenotype of the WNIN/Ob strain, possibly through up‐regulation of the BAT‐UCP1 gene and associated adipose tissue loss. However, in vitamin A‐supplemented lean and carrier rats, changes in adiposity could not be related to BAT‐UCP1 expression levels.
Obesity Disease Management Opportunities and Barriers
Authors: Sidorov Jaan E. , Fitzner Karen
Published: April 2008

Disease management, a system of coordinated health care interventions and communications for chronically ill populations, relies on patient education and case management to engage individuals in the management of their condition. Disease management also aims to enhance the quality of interactions between doctors and patients and advance evidence‐based medicine. Because these programs’ interventions frequently include helping individuals who suffer comorbidities associated with obesity to reduce their BMI, adaptation of disease management to populations with obesity seems a viable option. A major barrier for implementing disease management for obesity, however, is the lack of proven return on investment, which limits health plan and disease management organization interest. Purchaser demand may overcome this reluctance. Further research is needed to objectively test whether disease management interventions would be clinically effective for obese populations, produce positive financial outcomes for insurers, and enhance workplace productivity.
Dihydrotestosterone Treatment Results in Obesity and Altered Lipid Metabolism in Orchidectomized Mice
Authors: Movérare‐Skrtic Sofia , Venken Katrien , Andersson Niklas , Lindberg Marie K. , Svensson Johan , Swanson Charlotte , Vanderschueren Dirk , Oscarsson Jan , Gustafsson Jan‐Åke , Ohlsson Claes
Published: April 2008

Objective: To determine the role of androgen receptor (AR) activation for adipose tissue metabolism. Sex steroids are important regulators of adipose tissue metabolism in men. Androgens may regulate the adipose tissue metabolism in men either directly by stimulation of the AR or indirectly by aromatization of androgens into estrogens and, thereafter, by stimulation of the estrogen receptors. Previous studies have shown that estrogen receptor α stimulation results in reduced fat mass in men.

Research Methods and Procedures: Orchidectomized mice were treated with the non‐aromatizable androgen 5α‐dihydrotestosterone (DHT), 17β‐estradiol, or vehicle. VO2, VCO2, resting metabolic rate, locomotor activity, and food consumption were measured. Furthermore, changes in hepatic gene expression were analyzed.

Results: DHT treatment resulted in obesity, associated with reduced energy expenditure and fat oxidation. In contrast, DHT did not affect food consumption or locomotor activity. Furthermore, DHT treatment resulted in increased high‐density lipoprotein‐cholesterol and triglyceride levels associated with markedly decreased 7α‐hydroxylase gene expression, indicating decreased bile acid production.

Discussion: We showed that AR activation results in obesity and altered lipid metabolism in orchidectomized mice. One may speculate that AR antagonists might be useful in the treatment of obesity in men.