bluuebunny/crossref_metadata_2025 huggingface dataset:
Body Weight and Health Status: Importance of Socioeconomic Position and Working Conditions
Authors: Laaksonen Mikko , Sarlio‐Lähteenkorva Sirpa , Leino‐Arjas Päivi , Martikainen Pekka , Lahelma Eero
Published: April 2008

Objective: To examine the association between relative body weight and health status and the potential modifying effects of socioeconomic position and working conditions on this association.

Research Methods and Procedures: The data were derived from three identical cross‐sectional surveys conducted in 2000, 2001, and 2002. Respondents to postal surveys were middle‐aged employees of the City of Helsinki (7148 women and 1799 men, response rate 67%). BMI was based on self‐reported weight and height. Health status was measured by the Short‐Form 36 subscales and component summaries.

Results: Body weight was inversely associated with physical health, but in mental health, differences between BMI categories were small and inconsistent. In women, physical health deteriorated monotonically with increasing BMI, whereas in men, poor physical health was found among the obese only. Socioeconomic position did not modify the association between BMI and health. In women, the association between body weight and physical health became stronger with decreasing job control and increasing physical work load, whereas in men, a similar modifying effect was found for high job demands.

Discussion: Body weight was associated with physical health only. Lower levels of relative weight in women than in men may be associated with poor physical health. High body weight combined with adverse working conditions may impose a double burden on physical health.
Tanner Staging of Secondary Sexual Characteristics and Body Composition, Blood Pressure, and Insulin in Black Girls
Authors: Hoffman William H. , Barbeau Paule , Litaker Mark S. , Johnson Maribeth H. , Howe Cheryl A. , Gutin Bernard
Published: April 2008

Objective: To assess Tanner staging (breast and pubic hair development) and its relationship to measures of body composition, blood pressure, and fasting insulin and glucose in young black girls.

Research Methods and Procedures: Subjects were 138 black girls, 8 to 12 years of age, recruited from elementary schools in low socioeconomic status neighborhoods. Exclusion criteria included the presence of any acute/chronic medical conditions. Pubertal stages were assessed by one of two pediatricians and analyzed individually, as well as with a composite index (prepubertal, pubertal/premenarcheal, or pubertal/menarcheal). Glucose and insulin were measured after a 12‐hour fast. Measures of body composition included height, weight, BMI, waist and hip circumferences, fat mass, fat‐free soft tissue, bone mineral density (DXA), and visceral adipose tissue (magnetic resonance imaging). Resting systolic and diastolic blood pressure were measured by Dinamap.

Results: With age in the model, breast development explained significant proportions of the variance in height, weight, fat‐free soft tissue, bone mineral density, and insulin. Adding pubic hair development or menarche to those models did not significantly increase the proportion of variance that was explained by breast development. Furthermore, using a composite index of pubertal staging explained a smaller proportion of the variance compared with breast development alone.

Discussion: Combined with age, breast development was a better predictor of body composition and fasting insulin than was pubic hair development or a composite index of pubertal staging.
Best Practice Recommendations for Surgical Care in Weight Loss Surgery
Authors: Kelly John , Tarnoff Michael , Shikora Scott , Thayer Bruce , Jones Daniel B. , Forse R. Amour , Hutter Matthew M. , Fanelli Robert , Lautz David , Buckley Frederick , Munshi Imtiaz , Coe Nicolas
Published: April 2008

Objective: To establish evidence‐based guidelines for best practices for surgical care in weight loss surgery (WLS).

Research Methods and Procedures: We carried out a systematic search of English‐language literature on WLS in MEDLINE and the Cochrane Library. Key words were used to narrow the field for a selective review of abstracts. Data extraction was performed, and evidence categories were assigned according to a grading system based on established evidence‐based models.

Results: We assessed types of WLS, recommended guidelines for appropriateness, developed strategies for medical error reduction, established criteria for credentialing of systems and practitioners, and specified research needed for the future.

Discussion: Surgeon training, credentialing, and type of surgery performed were identified as key factors in patient safety. Other important issues in the delivery of best practice care included appropriate patient selection; use of a multidisciplinary treatment team; facility staffing, equipment, and administrative support; and early recognition and proper management of complications.
Behavioral and Psychological Factors in the Assessment and Treatment of Obesity Surgery Patients
Authors: Greenberg Isaac , Perna Frank , Kaplan Marjory , Sullivan Mary Anna
Published: April 2008

Objective: To provide evidence‐based guidelines on the psychological and behavioral screening of weight loss surgery (WLS) candidates and the impact of psychosocial factors on behavior change after gastric bypass surgery.

Research Methods and Procedures: The members of the Behavioral and Psychological subgroup of the Multidisciplinary Care Task Group conducted searches of MEDLINE and PubMed for articles related to WLS, behavior changes, and mental health, including quality of life (QOL) and behavior modification. Pertinent abstracts and literature were reviewed for references. A total of 198 abstracts were identified; 17 papers were reviewed in detail. Search periods were from 1980 to 2004.

Results: We found a high incidence of depression, negative body image, eating disorders, and low QOL in severely obese patients. Our task subgroup recommended that all WLS candidates be evaluated by a licensed mental health care provider (i.e., psychiatrist, psychologist, or social worker), experienced in the treatment of severely obese patients and working within the context of a multidisciplinary care team. We also recommended development of pre‐ and postsurgical treatment plans that address psychosocial contraindications for WLS and potential barriers to postoperative success.

Discussion: The psychological consequences of obesity can range from lowered self‐esteem to clinical depression. Rates of anxiety and depression are three to four times higher among obese individuals than among their leaner peers. A comprehensive multidisciplinary program that incorporates psychological and behavior change services can be of critical benefit in enhancing compliance, outcome, and QOL in WLS patients.
Specialized Staff and Equipment for Weight Loss Surgery Patients: Best Practice Guidelines
Authors: Whittemore Anthony D. , Kelly John , Shikora Scott , Cella Robert J. , Clark Thom , Selbovitz Leslie , Flint Loring
Published: April 2008

Objective: To provide evidence‐based guidelines on the specialized personnel, equipment, and physical plant required for safe and effective care of severely obese weight loss surgery (WLS) patients.

Research Methods and Procedures: We examined MEDLINE (Ovid and PubMed) and the Cumulative Index of Nursing and Allied Health Literature for articles on facilities resources for care of WLS patients published in English between January 1980 and March 2004. We queried several web sites for appropriate references; these included the Agency for Healthcare Research and Quality and the American College of Surgeons. The majority of reference material was descriptive and not specific to facilities resources for WLS patients. We identified a substantial body of literature on the general subject of patient safety; three of these articles were used to develop recommendations on the use of technology for medical error reduction. All other recommendations are based on 11 expert opinion reports.

Results: We recommended adequate training and credentialing for all medical staff; dedicated support and administrative personnel; and specialized interventional, diagnostic, operating room, and transport equipment. We specified needed adaptations to the physical plant and developed evidence‐based guidelines for medical error reduction and systems improvements.

Discussion: Specialized resources and dedicated staff are needed to protect the health of WLS surgery patients and staff. Adaptations include preoperative preparation for safe means of patient transport; techniques of anesthesia and intraoperative exposure; provisions for postoperative recovery; and measures to assure postoperative patient safety, hygiene, and comfort.
Coding and Reimbursement for Weight Loss Surgery: Best Practice Recommendations
Authors: Kaplan Lee M. , Fallon John A. , Mun Edward C. , Harvey Alan M. , Kastrinakis William V. , Johnson Elvira Q. , Nierman Robert S. , Keroack Christopher R.
Published: April 2008

Objective: To review the use and usefulness of billing codes for services related to weight loss surgery (WLS) and to examine third party reimbursement policies for these services.

Research Methods and Procedures: The Task Group carried out a systematic search of MEDLINE, the Internet, and the trade press for publications on WLS, coding, reimbursement, and coding and reimbursement policy. Twenty‐eight articles were each reviewed and graded using a system based on established evidence‐based models. The Massachusetts Dietetics Association provided reimbursement data for nutrition services. Three suppliers of laparoscopic WLS equipment provided summaries of coding and reimbursement information. WLS program directors were surveyed for information on use of procedure codes related to WLS.

Results: Recommendations focused on correcting or improving on the current lack of congruity among coding practices, reimbursement policies, and accepted clinical practice; lack of uniform coding and reimbursement data across institutions; inconsistent and/or inaccurate diagnostic and billing codes; inconsistent insurance reimbursement criteria; and inability to leverage reimbursement and coding data to track outcomes, identify best practices, and perform accurate risk‐benefit analyses.

Discussion: Rapid changes in the prevalence of obesity, our understanding of its clinical impact, and the technologies for surgical treatment have yet to be adequately reflected in coding, coverage, and reimbursement policies. Issues identified as key to effective change include improved characterization of the risks, benefits, and costs of WLS; anticipation and monitoring of technological advances; encouragement of consistent patterns of insurance coverage; and promotion of billing codes for WLS procedures that facilitate accurate tracking of clinical use and outcomes.
Increased Susceptibility to Insulin Resistance Associated with Abdominal Obesity in Aging Rats**
Authors: Catalano Karyn J. , Bergman Richard N. , Ader Marilyn
Published: April 2008

Objective: Recent data have suggested that the insulin resistance observed with aging may be more related to adiposity than aging per se. We asked whether the insulin resistance observed in aged rats was comparable (both in magnitude and location) to that of fat‐fed rats.

Research Methods and Procedures: We performed hyperinsulinemic (5 mU/min per kg) euglycemic clamps with tracer in conscious, 6‐hour fasted young (YL), fat‐fed young (YF), fat‐fed old (OF), and calorically restricted old (OL) rats.

Results: Intraabdominal fat measurements showed that OF and YF rats were more obese than YL (p ≤ 0.001; YF > OF > YL). Caloric restriction not only prevented age‐related obesity but also reduced the ratio of intraabdominal fat to lean body mass (LBM) compared with YL (OL: 0.59 ± 0.05 vs. YL: 1.07 ± 0.04; p = 0.017). Despite similar incremental insulin, YF and OF rats required 40% less infused glucose to maintain euglycemia than YL and OL rats (p < 0.001). Insulin‐stimulated glucose uptake (SiRd: ΔRd/(ΔInsulin × GlucoseSS) was impaired in OF rats (OF: 14.03 ± 1.79 vs. YL: 23.08 ± 1.87 × 103 dL/min × kg LBM per pM; p = 0.004) and improved in OL rats (29.41 ± 1.84 × 103 dL/min × kg LBM per pM; p = 0.031) compared with YL. Despite greater obesity, YF rats did not exhibit lower SiRd compared with OF rats (p = 0.58). In contrast, the ability of insulin to suppress endogenous glucose production (EGP; SiEGP: ΔEGP/(ΔInsulin × GlucoseSS) was not impaired in OF rats (OF vs. YL; p = 0.61) but was markedly impaired in YF rats by ∼75% (1.72 ± 0.66 × 103 dL/min × kg per pM; p = 0.013). Surprisingly, separate regression analysis for old and young animals revealed that old rats exhibited a significantly steeper regression between Si (Rd and EGP) and adiposity than young rats (p < 0.05). Thus, older rats showed a proportionately greater decrement in insulin sensitivity with an equivalent increase in adiposity.

Discussion: These data suggest that, in rodents, youth affords significant protection against obesity‐induced insulin resistance.
Heritability of Body Composition Measured by DXA in the Diabetes Heart Study
Authors: Hsu Fang‐Chi , Lenchik Leon , Nicklas Barbara J. , Lohman Kurt , Register Thomas C. , Mychaleckyj Josyf , Langefeld Carl D. , Freedman Barry I. , Bowden Donald W. , Carr J. Jeffrey
Published: April 2008

Objective: The purpose of this study was to investigate the heritability of body composition measured by DXA in the Diabetes Heart Study (DHS).

Research Methods and Procedures: Participants were 292 women and 262 men (age, 38 to 86 years; BMI, 17 to 57 kg/m2) from 244 families. There were 492 white and 49 African‐American sibling pairs. DXA measurements of percentage fat mass (FM), whole body FM, and lean mass (LM), as well as regional measurements of trunk fat mass (TFM) and appendicular lean mass (ALM), were obtained. Heritability of FM, LM, and BMI were estimated using Sequential Oligogenic Linkage Analysis Routines.

Results: After adjusting for age, gender, ethnicity, and height, the heritability estimates of various compositional attributes were %FM = 0.64, whole body FM = 0.71, TFM = 0.63, whole body LM = 0.60, ALM = 0.66, and BMI = 0.64 (all p < 0.0001). Additional adjustment for diabetes status, smoking, dietary intake, and physical activity resulted in only minor changes in the heritability estimates (ĥ2 = 0.63 to 0.72, all p < 0.0001). Furthermore, heritability of TFM after additional adjustment for whole body FM was significant (ĥ2 = 0.55, p < 0.0001), and heritability of ALM after additional adjustment for whole body LM was also significant (ĥ2 = 0.51, p < 0.0001).

Discussion: These data suggest that FM and LM measured by DXA are highly heritable and can be effectively used in designing linkage studies to locate genes governing body composition. In addition, regional distribution of FM and LM may be genetically determined.
Depressive Mood and Abdominal Fat Distribution in Overweight Premenopausal Women
Authors: Lee Eon Sook , Kim Yang Hyun , Beck Sung‐Ho , Lee Sangyeoup , Oh Sang Woo
Published: April 2008

Objective: There is increasing evidence that depressive mood is associated with central obesity, but little is known about the association between depression and abdominal fat distribution. This study investigated this relationship in premenopausal women.

Research Methods and Procedures: We recruited 101 overweight premenopausal women who had no eating disorders as defined using the DSM IV criteria. Depressive mood was assessed using Zung's Self‐Rating Depression Scale (SDS). Areas of visceral (VAT) and subcutaneous (SAT) adipose tissue at the level of vertebral body L4–L5 were measured using computed tomography. Associations of VAT, SAT, and the ratio of VAT to SAT with natural logarithmic transformation [(ln)]SDS were evaluated using linear regression. Anthropometric indices and physical fitness were also measured. Information on socioeconomic status, education level, and alcohol and smoking habits was obtained using self‐administered questionnaires. A hospital nutritionist assessed nutritional status. All of these factors were adjusted for as possible confounding factors in the analyses.

Results: The (ln)SDS score showed a positive association with the area of VAT, even after adjusting for the confounders mentioned above (p < 0.01). BMI, waist circumference, maximal oxygen uptake, and age were also associated with the area of VAT (all p < 0.05). In contrast, the (ln)SDS score was not associated with SAT (p > 0.10).

Discussion: We showed that depressive mood is associated with VAT, not with SAT, in overweight premenopausal women. These findings may explain some of the association between depression and coronary heart disease. More studies are needed to elucidate the causal relationship.
Prevalence of Weight Cycling and its Relation to Health Indicators in Finland
Authors: Lahti‐Koski Marjaana , Männistö Satu , Pietinen Pirjo , Vartiainen Erkki
Published: April 2008

Objective: This study was performed to identify weight cyclers and to assess the prevalence of weight cycling and its relation to health indicators in Finnish adults.

Research Methods and Procedures: Data for the study consisted of 3320 men and 3540 women (25 to 64 years of age). The subjects went through a health examination, and data on intentional weight losses and regains during the last 10 years were collected by a questionnaire. The subjects were divided into five groups: severe weight cyclers (weight loss ≥ 5 kg at least three times with regain), mild weight cyclers (weight loss ≥ 5 kg one to two times and regain), successful dieters (weight loss ≥ 5 kg with no regain), nonobese nondieters, and obese nondieters.

Results: Approximately 7% of men and 10% of women were defined as severe weight cyclers, and an additional 11% and 19% were defined as mild weight cyclers, respectively. In men, 20% of severe weight cyclers and 15% of obese nondieters perceived their health as poor, whereas in other groups, these proportions were <10%. In both sexes, severe weight cyclers seemed to have visited a doctor more frequently than nonobese nondieters. Severe weight cyclers were also more likely to use some medication compared with other groups.

Discussion: Weight cycling is more common in women than in men, and it seems to be associated with more regular visits to a doctor and poor self‐perceived health. However, because of the cross‐sectional design of the study, causal conclusions cannot be drawn.
The Human Obesity Gene Map: The 2004 Update
Authors: Pérusse Louis , Rankinen Tuomo , Zuberi Aamir , Chagnon Yvon C. , Weisnagel S. John , Argyropoulos George , Walts Brandon , Snyder Eric E. , Bouchard Claude
Published: April 2008

This paper presents the eleventh update of the human obesity gene map, which incorporates published results up to the end of October 2004. Evidence from single‐gene mutation obesity cases, Mendelian disorders exhibiting obesity as a clinical feature, transgenic and knockout murine models relevant to obesity, quantitative trait loci (QTLs) from animal cross‐breeding experiments, association studies with candidate genes, and linkages from genome scans is reviewed. As of October 2004, 173 human obesity cases due to single‐gene mutations in 10 different genes have been reported, and 49 loci related to Mendelian syndromes relevant to human obesity have been mapped to a genomic region, and causal genes or strong candidates have been identified for most of these syndromes. There are 166 genes which, when mutated or expressed as transgenes in the mouse, result in phenotypes that affect body weight and adiposity. The number of QTLs reported from animal models currently reaches 221. The number of human obesity QTLs derived from genome scans continues to grow, and we have now 204 QTLs for obesity‐related phenotypes from 50 genome‐wide scans. A total of 38 genomic regions harbor QTLs replicated among two to four studies. The number of studies reporting associations between DNA sequence variation in specific genes and obesity phenotypes has also increased considerably with 358 findings of positive associations with 113 candidate genes. Among them, 18 genes are supported by at least five positive studies. The obesity gene map shows putative loci on all chromosomes except Y. Overall, >600 genes, markers, and chromosomal regions have been associated or linked with human obesity phenotypes. The electronic version of the map with links to useful publications and genomic and other relevant sites can be found at http:obesitygene.pbrc.edu.
E‐Selectin Genotypes and Risk of Type 2 Diabetes in Women
Authors: Meigs James B. , Hu Frank B. , Perhanidis Jessica S. , Hunter David , Rifai Nader , Manson JoAnn E.
Published: April 2008

Endothelial dysfunction increases risk for type 2 diabetes. We examined whether variation in the gene for E‐selectin (SELE), a biomarker of endothelial dysfunction, was associated with levels of E‐selectin or diabetes quantitative traits (including fasting levels of insulin and hemoglobin A1c) in 719 nondiabetic participants of the Nurses’ Health Study or with risk of diabetes in 602 incident (over 10 years of follow‐up) cases and 655 control women matched for age, race, and fasting status. Variation in three single nucleotide polymorphisms previously associated with cardiovascular disease risk and having effects on E‐selectin function, S128R, G98T, and L554F, was not significantly (p > 0.05) associated with levels of E‐selectin or diabetes quantitative traits, or with risk of incident diabetes in the primary analysis. Among women with low levels of subclinical inflammation (C‐reactive protein levels below the population median), S128R R allele carriers had a diabetes risk factor‐adjusted relative risk of incident diabetes of 1.71 (95% confidence interval, 1.04 to 2.81) relative to those with the SS genotype. Apart from an association in this subgroup, we conclude that the E‐selectin variants we examined are not important genetic risk factors for type 2 diabetes in women.
Interactive Effects Between Polymorphisms in the β‐Adrenergic Receptors and Longitudinal Changes in Obesity
Authors: Ellsworth Darrell L. , Coady Sean A. , Chen Wei , Srinivasan Sathanur R. , Boerwinkle Eric , Berenson Gerald S.
Published: April 2008

We assessed interactions between polymorphisms in the β‐adrenergic receptor genes and longitudinal changes in obesity from childhood to adulthood using longitudinal data collected over a 24‐year period from 1973 to 1996. Sex‐ and age‐stratified analyses using random coefficients models were used to examine gene—gene interaction effects on obesity measures in 1179 African‐American and white men and women (71% white, 57% women). Suggestive evidence for an interaction (p = 0.022) between the β1‐ and β2‐adrenergic receptors was observed in men for longitudinal change in BMI. Men with Gly/Gly genotypes for both the β1 and β2 receptors showed significant increases (∼0.6%/yr) in BMI from childhood to adulthood. Women showed suggestive evidence for an interaction (p = 0.035) between the β1‐ and β3‐adrenergic receptors for change over time in BMI. Women with Gly/Gly genotypes at the β1‐receptor and carrying at least one β3‐Arg allele showed notable increases in BMI. The regulation of lipolysis and development of obesity differ markedly between men and women and may be influenced by genetic polymorphisms, which contribute to the efficiency of the β‐adrenergic receptors, and hormonal effects on adrenergic receptor activity.
Adenosinergic Modulation of Ventilation in Obese Zucker Rats
Authors: Lee Shin‐Da , Nakano Hitoshi , Farkas Gaspar A.
Published: April 2008

Objectives: The goal of our study was to determine whether altered adenosinergic mechanisms contribute to the depressed ventilatory response observed in obese Zucker rats.

Research Methods and Procedures: Eight lean and eight obese Zucker rats were studied at 7 to 8 weeks of age. Ventilation (V˙E) during room air, during 5‐minute hypercapnic (7% CO2, balance O2), and during 30‐minute sustained hypoxic (10% O2) exposures were sequentially measured by the barometric method on three separate occasions after the randomized blinded administration of equal volumes of either saline (control), 8‐(p‐sulfophenyl)‐theophylline (8‐PST, 7 mg/kg, peripheral adenosine antagonist), or aminophylline (AMPH, 15 mg/kg, peripheral and central adenosine antagonist).

Results: During room air and hypercapnic exposures, AMPH (but not 8‐PST) significantly (p < 0.05) increased V˙E in both lean and obese rats. During acute (2 minute) hypoxic exposure, 8‐PST (but not AMPH) significantly depressed V˙E in lean rats. In contrast, AMPH (but not 8‐PST) selectively increased V˙E in obese rats. During sustained (10 to 30 minutes) hypoxic exposure, neither AMPH nor 8‐PST administration altered V˙E in lean rats. In contrast, AMPH (but not 8‐PST) selectively increased V˙E during the late response in obese rats.

Discussion: Our findings indicate that obese rats possess altered adenosinergic modulation of ventilatory responses to acute and sustained hypoxia in two opposite ways. We conclude that the reduced hypoxic ventilatory response observed in obese Zucker rats is attributed to depressed adenosinergic peripheral excitatory mechanisms and to enhanced adenosinergic central depression mechanisms, both of which contribute to the blunted ventilatory response in obesity.
Glucose Tolerance and Skeletal Muscle Gene Expression in Response to Alternate Day Fasting
Authors: Heilbronn Leonie K. , Civitarese Anthony E. , Bogacka Iwona , Smith Steven R. , Hulver Matthew , Ravussin Eric
Published: April 2008

Objective: Alternate day fasting may extend lifespan in rodents and is feasible for short periods in nonobese humans. The aim of this study was to examine the effects of 3 weeks of alternate day fasting on glucose tolerance and skeletal muscle expression of genes involved in fatty acid transport/oxidation, mitochondrial biogenesis, and stress response.

Research Methods and Procedures: Glucose and insulin responses to a standard meal were tested in nonobese subjects (eight men and eight women; BMI, 20 to 30 kg/m2) at baseline and after 22 days of alternate day fasting (36 hour fast). Muscle biopsies were obtained from a subset of subjects (n = 11) at baseline and on day 21 (12‐hour fast).

Results: Glucose response to a meal was slightly impaired in women after 3 weeks of treatment (p < 0.01), but insulin response was unchanged. However, men had no change in glucose response and a significant reduction in insulin response (p < 0.03). There were no significant changes in the expression of genes involved in mitochondrial biogenesis or fatty acid transport/oxidation, although a trend toward increased CPT1 expression was observed (p < 0.08). SIRT1 mRNA expression was increased after alternate day fasting (p = 0.01).

Discussion: Alternate day fasting may adversely affect glucose tolerance in nonobese women but not in nonobese men. The gene expression results indicate that fatty acid oxidation and mitochondrial biogenesis are unaffected by alternate day fasting. However, the increased expression in SIRT1 suggests that alternate day fasting may improve stress resistance, a commonly observed feature of calorie‐restricted rodents.
Sedentary Behavior, Physical Activity, and the Metabolic Syndrome among U.S. Adults
Authors: Ford Earl S. , Kohl Harold W. , Mokdad Ali H. , Ajani Umed A.
Published: April 2008

Objective: We examined the associations among physical activity, sedentary behavior, and metabolic syndrome in a representative sample of U.S. adults.

Research Methods and Procedures: A total of 1626 men and women ≥20 years old from National Health and Nutrition Examination Survey 1999 to 2000 who attended the morning examination were evaluated. The metabolic syndrome was defined by using the definition from the National Cholesterol Education Program.

Results: In unadjusted analysis, participants who did not engage in any moderate or vigorous physical activity during leisure time had almost twice the odds of having metabolic syndrome [odds ratio (OR), 1.90; 95% confidence interval (CI), 1.22 to 2.97] as those who reportedly engaged in ≥150 min/wk of such activity. Adjustment for age, sex, race or ethnicity, educational status, smoking status, and alcohol use attenuated the OR (OR, 1.46; 95% CI, 0.87 to 2.45). Compared with participants who watched television or videos or used a computer <1 h/d outside of work, the adjusted ORs for having metabolic syndrome were 1.41 (95% CI 0.80 to 2.51) for 1 h/d, 1.37 (95% CI 0.85 to 2.20) for 2 h/d, 1.70 (95% CI 0.92 to 3.14) for 3 h/d, and 2.10 (95% CI 1.27 to 3.47) for ≥4 h/d. Additional adjustment for physical activity or sedentary behavior minimally affected the ORs.

Discussion: Sedentary behavior is an important potential determinant of the prevalence of the syndrome. Efforts to lessen the amount of time that U.S. adults spend watching television or videos or using a computer, especially if coupled to increases in physical activity, could result in substantial decreases in the prevalence of metabolic syndrome.
Effects of Exercise on Metabolic Risk Variables in Overweight Postmenopausal Women: A Randomized Clinical Trial
Authors: Frank Laura Lewis , Sorensen Bess E. , Yasui Yutaka , Tworoger Shelley S. , Schwartz Robert S. , Ulrich Cornelia M. , Irwin Melinda L. , Rudolph Rebecca E. , Rajan Kumar B. , Stanczyk Frank , Bowen Deborah , Weigle David S. , Potter John D. , McTiernan Anne
Published: April 2008

Objective: This study examined the effects of exercise on metabolic risk variables insulin, leptin, glucose, and triglycerides in overweight/obese postmenopausal women.

Research Methods and Procedures: Sedentary women (n = 173) who were overweight or obese (BMI ≥ 25 kg/m2 or ≥24 kg/m2 with ≥33% body fat), 50 to 75 years of age, were randomized to 12 months of exercise (≥45 minutes of moderate‐intensity aerobic activity 5 d/wk) or to a stretching control group. Body composition (DXA) and visceral adiposity (computed tomography) were measured at baseline and 12 months. Insulin, glucose, triglycerides, and leptin were measured at baseline and 3 and 12 months. Insulin resistance was evaluated by the homeostasis model assessment formula. Differences from baseline to follow‐up were calculated and compared across groups.

Results: Exercisers had a 4% decrease and controls had a 12% increase in insulin concentrations from baseline to 12 months (p = 0.0002). Over the same 12‐month period, leptin concentrations decreased by 7% among exercisers compared with remaining constant among controls (p = 0.03). Homeostasis model assessment scores decreased by 2% among exercisers and increased 14% among controls from baseline to 12 months (p = 0.0005). The exercise effect on insulin was modified by changes in total fat mass (trend, p = 0.03), such that the exercise intervention abolished increases in insulin concentrations associated with gains in total fat mass.

Discussion: Regular moderate‐intensity exercise can be used to improve metabolic risk variables such as insulin and leptin in overweight/obese postmenopausal women. These results are promising for health care providers providing advice to postmenopausal women for lifestyle changes to reduce risk of insulin resistance, coronary heart disease, and diabetes.
Neuropeptides, Including Neuropeptide Y and Melanocortins, Mediate Lipolysis in Murine Adipocytes
Authors: Bradley Richard L. , Mansfield Julia P. R. , Maratos‐Flier Eleftheria
Published: April 2008

Objective: To determine whether key appetite‐regulating neuropeptides such as melanin‐concentrating hormone (MCH), neuropeptide Y (NPY), and α‐melanocyte—stimulating hormone (α‐MSH), which are known to mediate energy balance through centrally mediated pathways, also have direct acute effects on the lipolytic activity of murine adipocytes.

Research Methods and Procedures: Fully differentiated 3T3‐L1 adipocytes serum starved overnight in Dulbecco's modified Eagle medium containing 2% bovine serum albumin or freshly isolated mouse adipocytes were incubated for up to 2 hours in the absence and presence of 100 nM each of NPY, MCH, α‐MSH, the melanocortin receptor agonist MTII, or isoproterenol as a control. Free fatty acids secreted into the incubation medium were measured using a commercially available nonesterified fatty acid C test kit.

Results: Treatment of 3T3‐L1 cells with 100 nM NPY decreased basal free fatty acid secretion (basal, 0.006 ± 0.001 vs. NPY, 0.001 ± 0.0003 nM at 90 minutes; p < 0.05), whereas both α‐MSH and MTII stimulated up to a 7‐fold increase in free fatty acid release (MTII, 0.238 ± 0.004 vs. basal, 0.024 ± 0.002 nM at 2 hours; p < 0.05; and α‐MSH, 0.22 ± 0.005 vs. basal, 0.04 ± 0.003 nM at 2 hours; p < 0.05). Treatment with 100 nM MCH had no effect on basal free fatty acid release or on α‐MSH—induced lipolysis during concurrent treatment. Conversely, concurrent treatment with 100 nM NPY dramatically inhibited (by ∼90%) α‐MSH—induced lipolysis. Similar treatment of freshly isolated mouse adipocytes showed virtually identical results.

Discussion: In addition to their centrally mediated actions, appetite‐regulating neuropeptides modulate adipose tissue mass through direct peripheral effects. Systemic administration of pharmacological agents altering the effects of these neuropeptides may form the basis of future obesity therapies. Thus, some of these agents will likely have direct effects on adipocytes that may serve to alter their therapeutic effectiveness.
Regulation of Adiponectin Expression in Human Adipocytes: Effects of Adiposity, Glucocorticoids, and Tumor Necrosis Factor α
Authors: Degawa‐Yamauchi Mikako , Moss Katherine A. , Bovenkerk Jason E. , Shankar Sudha S. , Morrison Charles L. , Lelliott Christopher J. , Vidal‐Puig Antonio , Jones RoseMarie , Considine Robert V.
Published: April 2008

Objective: Adiponectin mRNA expression in isolated subcutaneous and omental adipocytes was examined across a wide range of adiposity to determine whether adiponectin synthesis is impaired in these adipose tissue depots in obese humans. Tumor necrosis factor (TNF)α and dexamethasone were tested for inhibitory effects on adiponectin release from human adipocytes in vitro.

Research Methods and Procedures: Adipocytes were isolated by collagenase digestion of abdominal adipose tissue obtained from subjects undergoing surgical procedures or outpatient needle biopsy. Adiponectin and leptin mRNA were quantitated by real‐time reverse transcriptase‐polymerase chain reaction. Adiponectin and leptin secretion from isolated adipocytes treated with dexamethasone or TNFα were determined by radioimmunoassay.

Results: There was a significant negative correlation between adiponectin gene expression and BMI in subcutaneous adipocytes from 32 women (r = 0.420; p = 0.02). Adiponectin mRNA was also significantly correlated with serum adiponectin (r = 0.44; p = 0.03; n = 25). There was no correlation between adiponectin mRNA expression and BMI in omental adipocytes from 29 women. Leptin mRNA was significantly and positively correlated (r = 0.484; p = 0.01) with BMI in the same omental adipocyte mRNA preparations. In subcutaneous adipocytes from lean subjects, TNFα inhibited adiponectin release by 7.4 ± 1.2% (n = 9, p < 0.05) but had no effect on adiponectin release from subcutaneous or omental adipocytes from obese subjects. Dexamethasone significantly inhibited adiponectin release with 24 hours of treatment.

Discussion: The data suggest that reduced adiponectin synthesis in subcutaneous adipocytes contributes to lower serum adiponectin levels in obesity and that glucocorticoids regulate adiponectin gene expression in human adipocytes. TNFα does not seem to directly inhibit adiponectin synthesis in human adipocytes.
Intentional Weight Loss Reduces Mortality Rate in a Rodent Model of Dietary Obesity
Authors: Vasselli Joseph R. , Weindruch Richard , Heymsfield Steven B. , Pi‐Sunyer F. Xavier , Boozer Carol N. , Yi Nengjun , Wang Chenxi , Pietrobelli Angelo , Allison David B.
Published: April 2008

Objective: We used a rodent model of dietary obesity to evaluate effects of caloric restriction‐induced weight loss on mortality rate.

Research Measures and Procedures: In a randomized parallel‐groups design, 312 outbred Sprague‐Dawley rats (one‐half males) were assigned at age 10 weeks to one of three diets: low fat (LF; 18.7% calories as fat) with caloric intake adjusted to maintain body weight 10% below that for ad libitum (AL)‐fed rat food, high fat (HF; 45% calories as fat) fed at the same level, or HF fed AL. At age 46 weeks, the lightest one‐third of the AL group was discarded to ensure a more obese group; the remaining animals were randomly assigned to one of three diets: HF‐AL, HF with energy restricted to produce body weights of animals restricted on the HF diet throughout life, or LF with energy restricted to produce the body weights of animals restricted on the LF diet throughout life. Life span, body weight, and leptin levels were measured.

Results: Animals restricted throughout life lived the longest (p < 0.001). Life span was not different among animals that had been obese and then lost weight and animals that had been nonobese throughout life (p = 0.18). Animals that were obese and lost weight lived substantially longer than animals that remained obese throughout life (p = 0.002). Diet composition had no effect on life span (p = 0.52).

Discussion: Weight loss after the onset of obesity during adulthood leads to a substantial increase in longevity in rats.
Decreased Glucagon‐like Peptide 1 Release after Weight Loss in Overweight/Obese Subjects
Authors: Adam Tanja C. M. , Jocken Johan , Westerterp‐Plantenga Margriet S.
Published: April 2008

Objective: Postprandial glucagon‐like peptide 1 (GLP‐1) release seems to be attenuated in obese subjects. Results on whether weight loss improves GLP‐1 release are contradictory. The aim of this study was to further investigate the effect of weight loss on basal and postprandial GLP‐1 release in overweight/obese subjects.

Research Methods and Procedures: Thirty‐two overweight/obese subjects participated in a repeated measurement design before (BMI, 30.3 ± 2.8 kg/m2; waist circumference, 92.6 ± 7.8 cm; hip circumference, 111.1 ± 7.4 cm) and after a weight loss period of 6 weeks (BMI, 28.2 ± 2.7 kg/m2; waist circumference, 85.5 ± 8.5 cm; hip circumference, 102.1 ± 9.2 cm). During weight loss, subjects received a very‐low‐calorie diet (Optifast) to replace three meals per day. Subjects came to the laboratory fasted, and after a baseline blood sample, received a standard breakfast (1.9 MJ). Postprandially, blood samples were taken every one‐half hour relative to intake for 120 minutes to determine GLP‐1, insulin, glucose, and free fatty acids from plasma. Appetite ratings were obtained with visual analog scales.

Results: After weight loss, postprandial GLP‐1 concentrations at 30 and 60 minutes were significantly lower than before weight loss (p < 0.05). Glucose concentrations were also lower, and free fatty acids were higher compared with before weight loss. Ratings of satiety were increased, and hunger scores were decreased after weight loss (p < 0.05).

Discussion: In overweight/obese subjects, GLP‐1 concentrations after weight loss were decreased compared with before weight loss, and nutrient‐related stimulation was abolished. This might be a response to a proceeding negative energy balance. Satiety and GLP‐1 seem to be unrelated in the long term.
Ghrelin Does Not Influence Gastric Emptying in Obese Subjects
Authors: Mora Maria E. Valera , Scarfone Antonino , Valenza Venanzio , Calvani Menotti , Greco Aldo V. , Gasbarrini Giovanni , Mingrone Geltrude
Published: April 2008

Objective: To evaluate the relationship between fasting plasma concentrations of ghrelin and gastric emptying in obese individuals compared with lean subjects.

Research Methods and Procedures: We included 20 obese patients (9 men and 11 women, BMI > 30 kg/m2) and 16 nonobese control subjects (7 men and 9 women, BMI ≤ 25 kg/m2). Gastric emptying of solids (egg sandwich labeled with radionuclide) was measured at 120 minutes with (99m)Tc‐single photon emission computed tomography imaging. Ghrelin and leptin were analyzed by radioimmunoassay and ELISA methods, respectively.

Results: The gastric half‐emptying time was similar in obese men and women (67.8 ± 14.79 vs. 66.6 ± 13.56 minutes) but significantly shorter (p < 0.001) than in the control population (men: 88.09 ± 11.72 minutes; women: 97.25 ± 10.31 minutes). Ghrelin levels were significantly lower in obese subjects (131.37 ± 47.67 vs. 306.3 ± 45.52 pg/mL; p < 0.0001 in men and 162.13 ± 32.95 vs. 272.8 ± 47.77 pg/mL; p < 0.0001 in women). A negative correlation between gastric emptying and fasting ghrelin levels was observed only in lean subjects (y = −0.2391x + 157.9; R2 = 0.95). Also, in the lean group, ghrelin was the only significant independent determinant of gastric emptying, explaining 98% of the variance (adjusted R2) in a multiple regression analysis.

Discussion: This report shows that, in humans, gastric emptying is faster in obese subjects than in lean controls and that, whereas ghrelin is the best determinant of gastric kinetics in healthy controls, this action is lost in obesity.
Survival Expectations of the Obese: Is Excess Mortality Reflected in Perceptions?
Authors: Falba Tracy A. , Busch Susan H.
Published: April 2008

Objective: This study compared self‐reported subjective life expectancy (i.e., probability of living to age 75) for normal‐weight, overweight, and obese weight groups to examine whether individuals are internalizing information about the health risks due to excessive weight.

Research Methods and Procedures: Using data from the Health and Retirement Study, a total of 9035 individuals 51 to 61 years old were analyzed by BMI category. The primary outcome measure was individuals’ reports about their own expectations of survival to age 75. Absolute and relative risks of survival were compared with published estimates of survival to age 75.

Results: Consistently, higher levels of BMI were associated with lower self‐estimated survival probabilities. Differences relative to normal weight ranged from 4.9% (p < 0.01) for male nonsmokers to 8.8% (p < 0.001) for female nonsmokers. However, these differences were substantially less than those obtained from published survival curve estimates, suggesting that obese individuals tended to underestimate mortality risks.

Discussion: Individuals appeared to underestimate the mortality risks of excessive weight; thus, knowledge campaigns about the risks of obesity should remain a top priority.
Altered Luteinizing Hormone and Testosterone Secretion in Middle‐Aged Obese Men with Obstructive Sleep Apnea
Authors: Luboshitzky Rafael , Lavie Lena , Shen‐Orr Zila , Herer Paula
Published: April 2008

Objective: To elucidate the causes for the decline in testosterone levels observed in men with obstructive sleep apnea (OSA).

Research Methods and Procedures: We determined serum luteinizing hormone (LH) and testosterone levels every 20 minutes between 7 pm and 7 am with simultaneous sleep recordings in five obese middle‐aged men with OSA, in five age‐ and BMI‐matched controls, and in six lean young healthy men.

Results: The mean and area under the curve (AUC) values of LH and testosterone were significantly lower in men with OSA compared with controls. Young controls had significantly more testosterone pulses of shorter interpulse duration than OSA subjects and middle‐aged controls. After adjusting for age and BMI, the three groups differed in mean and AUC values of LH and testosterone. Analysis of covariance, using BMI as a covariate, revealed a statistically significant group effect on mean and AUC testosterone values (p = 0.03; p < 0.003, respectively). Eliminating young controls, there was a significant positive correlation between the amount of LH and testosterone secreted at night. After partialling out age alone and BMI alone, the mean LH and mean testosterone were still positively correlated.

Discussion: Thus, OSA is associated with decreased pituitary‐gonadal function. The decline in testosterone concentrations is due to obesity and advanced age and to a lesser degree to sleep fragmentation and hypoxia.
Overweight and Obesity: Knowledge, Attitudes, and Practices of General Practitioners in France
Authors: Bocquier Aurélie , Verger Pierre , Basdevant Arnaud , Andreotti Gérard , Baretge Jean , Villani Patrick , Paraponaris Alain
Published: April 2008

Objective: To describe the current knowledge, attitudes, and practices of French general practitioners (GPs) in the field of adult overweight and obesity management.

Research Methods and Procedures: A cross‐sectional telephone survey interviewed a sample of 600 GPs, representative of the private GPs in southeastern France. A four‐part questionnaire assessed personal and professional characteristics, attitudes and opinions about overweight and obesity, relevant knowledge and training, and practices (diagnostic methods, clinical assessments, weight loss objectives, types of counseling).

Results: Most GPs knew that weight problems are health‐threatening, and 79% agreed that managing these problems is part of their role. Nevertheless, 58% did not feel they perform this role effectively, and one‐third did not find it professionally gratifying. Approximately 30% had negative attitudes toward overweight and obese patients; 57% were pessimistic about patients’ ability to lose weight; 64% often set weight loss objectives more demanding than guidelines call for; and neither food diaries nor nutritional education were used systematically. GPs’ feelings of effectiveness and attitudes toward obese patients were associated with some professional (training) and personal (BMI, personal diet experience) characteristics.

Discussion: GPs’ feelings of ineffectiveness may stem from an underlying conflict between practitioners’ and patients’ representations of weight problems and the relationship problems this causes. Inadequate practices and health care system organization may also play a role.
Comparison of Visceral Adipose Tissue Mass in Adult African Americans and Whites**
Authors: Hoffman Daniel J. , Wang ZiMian , Gallagher Dympna , Heymsfield Steven B.
Published: April 2008

Objective: Previous studies have reported racial differences in the amount of visceral adipose tissue (VAT), a risk factor for metabolic diseases. These results are equivocal and have not controlled for hormonal influences on VAT mass. This study was designed to measure the extent to which race is associated with VAT, controlling for total adipose tissue (TAT) mass and testosterone.

Research Methods and Procedures: Using a cross‐sectional study design, we measured TAT mass using DXA, VAT and subcutaneous adipose tissue mass using magnetic resonance imaging, and sex hormones using radioimmunoassay in 224 African‐American and white men and women.

Results: White men had increased VAT mass, even when controlling for TAT and age, compared with African‐American men. White women also had a higher VAT mass compared with African‐American women, but only when controlling for TAT and age. When multiple linear regression was used to evaluate the racial differences in VAT mass in a subset of subjects (n = 80), controlling for sex hormones, it was found that white men, but not women, had increased VAT mass compared with their African‐American counterparts.

Discussion: Based on the results of this study, we conclude that, when controlling for TAT, sex hormone levels, and age, white men, but not women, have more VAT mass than African‐American men and women. Additional studies are needed to explore possible environmental and genetic influences on fat distribution relative to race and sex.