bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatic‐dependent and ‐independent Insulin Actions Are Impaired in the Obese Zucker Rat Model
Authors: Afonso Ricardo A. , Ribeiro Rogerio T. , Fernandes Ana B. , Patarrão Rita S. , Macedo M. Paula
Published: July 2008

Objective: Whole‐body insulin sensitivity (IS) depends on a hepatic pathway, involving parasympathetic activation and hepatic nitric oxide (NO) production. Both atropine and N‐monomethyl‐l‐arginine (l‐NMMA, NO synthase inhibitor) induce insulin resistance (IR). IR is associated with obesity. Because NO action was shown to be impaired in animal models of obesity, such as the obese Zucker rat (OZR), we tested the hypothesis that the hepatic‐dependent pathway is diminished in OZR, resulting in IR.

Research Methods and Procedures: Lean Zucker rats (LZRs) were used as OZR controls. IS was evaluated in terms of glucose disposal [milligrams of glucose per kilogram of body weight (bw)]. Two groups were submitted to two protocols. First, a control clamp was followed by a post‐atropine (3 mg/kg intravenously) clamp. Second, after the control clamp, l‐NMMA (0.73 mg/kg intraportally) was given, and a second clamp was performed. Hepatic‐dependent IS was assessed by subtracting the response after atropine or l‐NMMA from the basal response.

Results: In the first protocol, basal IS was lower in OZR than in LZR (OZR, 73.7 ± 14.2; LZR, 289.2 ± 24.7 mg glucose/kg bw; p < 0.001), and atropine decreased IS in the same proportion for both groups (OZR, 41.3 ± 8.0%; LZR, 40.1 ± 6.5%). Equally, in the second protocol, OZR presented lower IS (OZR, 79.3 ± 1.6; LZR, 287.4 ± 22.7 mg glucose/kg bw; p < 0.001). l‐NMMA induced IS inhibition in both groups (OZR, 48.3 ± 6.6%; LZR, 46.4 ± 4.1%), similar to that after atropine.

Discussion: We show that the IR in OZR is due to similar impairment of both hepatic‐dependent and ‐independent components of insulin action, suggesting the existence of a defect common to both pathways.
Expression and Localization of Melanocortin‐1 Receptor in Human Adipose Tissues of Severely Obese Patients
Authors: Hoch Matthias , Eberle Alex N. , Wagner Urs , Bussmann Christian , Peters Thomas , Peterli Ralph
Published: July 2008

Objective: The melanocortin system is a key regulator in the hypothalamus of energy intake and expenditure. It is frequently linked with obesity and apparently modulates sympathetic outflow to white adipose tissues. The role of the melanocortins within adipose tissues, however, is not entirely clear. This study was aimed at determining the quantitative expression of the five melanocortin receptors (MC1‐R to MC5‐R) in subcutaneous and omental fat of obese patients and non‐obese subjects.

Research Methods and Procedures: Expression of MC1‐R to MC5‐R, proopiomelanocortin, agouti signaling protein, leptin, leptin receptor, and uncoupling protein‐1 was investigated in human fat samples by quantitative reverse transcription‐polymerase chain reaction. MC1‐R expression was also studied in preadipocytes, adipocytes, and monocytic THP‐1 cells and by immunohistochemical localization in adipose tissues.

Results: Notable expression was found for MC1‐R, whereas no mRNA for MC2‐R and MC3‐R was detected; MC4‐R and MC5‐R mRNA was occasionally detectable but at very low levels. MC1‐R mRNA in subcutaneous fat was increased in obese patients as compared with controls; omental fat of both groups had slightly higher MC1‐R expression than subcutaneous fat and did not differ between patient groups. Immunohistochemical analysis of the MC1‐R in adipose tissue sections showed that MC1‐R expression was higher in macrophages but also present in adipocytes.

Discussion: The expression of MC1‐R and the lack of MC2‐R in human adipose tissues indicate that the melanocortins may regulate cell proliferation and/or inflammatory signals rather than lipolysis. Also, the increased expression of MC1‐R in subcutaneous fat of obese subjects may reflect one aspect of the pathophysiology of obesity.
Galectin‐3 Stimulates Preadipocyte Proliferation and Is Up‐regulated in Growing Adipose Tissue
Authors: Kiwaki Kohji , Novak Colleen M. , Hsu Daniel K. , Liu Fu‐Tong , Levine James A.
Published: July 2008

Objective: Some cytokines and mediators of inflammation can alter adiposity through their effects on adipocyte number. To probe the molecular basis of obesity, this study determined whether galectin‐3 was present in adipose tissue and investigated its effects on fat cell number.

Research Methods and Procedures: In the first study, obesity‐prone C57BL/6J mice were fed with high‐fat (58%) diet. Epididymal fat pads were collected at Day 0, Day 60, and Day 120 after the start of high‐fat feeding.

Results: Levels of adipocyte galectin‐3 protein, determined using Western blot analysis, increased as the mice became obese. Galectin‐3 mRNA and protein were then detected in human adipose tissue, primarily in the preadipocyte fraction. It was found that recombinant human galectin‐3 stimulated proliferation of primary cultured preadipocytes as well as DNA synthesis through lectin‐carbohydrate interaction.

Discussion: Galectin‐3, which has been known to play a versatile role especially in immune cells, might play a role also in adipose tissue and be associated with the pathophysiology of obesity.
Prevalence and Risk Factors of Overweight and Obesity in China
Authors: Reynolds Kristi , Gu Dongfeng , Whelton Paul K. , Wu Xigui , Duan Xiufang , Mo Jingping , He Jiang ,   For the InterASIA Collaborative Group
Published: July 2008

Objective: To examine the prevalence and risk factors of overweight and obesity in China.

Research Methods and Procedures: A cross‐sectional survey was conducted in a nationally representative sample of 15,540 Chinese adults in 2000–2001. Body weight, height, and waist circumference were measured by trained observers. Overweight and obesity were defined according to the World Health Organization classification. Central obesity was defined according to guidelines of the International Diabetes Federation.

Results: Mean BMI and waist circumference were 23.1 kg/m2 and 79.6 cm, respectively, for men and 23.5 kg/m2 and 77.2 cm, respectively, for women. The prevalences of overweight and obesity were 24.1% and 2.8% in men and 26.1% and 5.0% in women, respectively. The prevalence of central obesity was 16.1% in men and 37.6% in women. The prevalences of overweight, obesity, and central obesity were higher among residents in northern China compared with their counterparts in southern China and among those in urban areas compared with those in rural areas. Lifestyle factors were the most important risk factors to explain the differences in overweight and central obesity between northern and southern residents. Among women, lifestyle and diet were the most important risk factors to explain the differences between urban and rural residents, whereas socioeconomic status, lifestyle, and diet were all important among men.

Discussion: Our study indicates that overweight and obesity have become important public health problems in China. Environmental risk factors may be the main reason for regional differences in the prevalence of overweight and obesity in China.
Adipose Tissue Interleukin‐18 mRNA and Plasma Interleukin‐18: Effect of Obesity and Exercise
Authors: Leick Lotte , Lindegaard Birgitte , Stensvold Dorthe , Plomgaard Peter , Saltin Bengt , Pilegaard Henriette
Published: July 2008

Objectives: Obesity and a physically inactive lifestyle are associated with increased risk of developing insulin resistance. The hypothesis that obesity is associated with increased adipose tissue (AT) interleukin (IL)‐18 mRNA expression and that AT IL‐18 mRNA expression is related to insulin resistance was tested. Furthermore, we speculated that acute exercise and exercise training would regulate AT IL‐18 mRNA expression.

Research Methods and Procedures: Non‐obese subjects with BMI < 30 kg/m2 (women: n = 18; men; n = 11) and obese subjects with BMI >30 kg/m2 (women: n = 6; men: n = 7) participated in the study. Blood samples and abdominal subcutaneous AT biopsies were obtained at rest, immediately after an acute exercise bout, and at 2 hours or 10 hours of recovery. After 8 weeks of exercise training of the obese group, sampling was repeated 48 hours after the last training session.

Results: AT IL‐18 mRNA content and plasma IL‐18 concentration were higher (p < 0.05) in the obese group than in the non‐obese group. AT IL‐18 mRNA content and plasma IL‐18 concentration was positively correlated (p < 0.05) with insulin resistance. While acute exercise did not affect IL‐18 mRNA expression at the studied time‐points, exercise training reduced AT IL‐18 mRNA content by 20% in both sexes.

Discussion: Because obesity and insulin resistance were associated with elevated AT IL‐18 mRNA and plasma IL‐18 levels, the training‐induced lowering of AT IL‐18 mRNA content may contribute to the beneficial effects of regular physical activity with improved insulin sensitivity.
Effect of a Thermogenic Beverage on 24‐Hour Energy Metabolism in Humans
Authors: Rudelle Servane , Ferruzzi Mario G. , Cristiani Isabelle , Moulin Julie , Macé Katherine , Acheson Kevin J. , Tappy Luc
Published: July 2008

Objective:To test whether consumption of a beverage containing active ingredients will increase 24‐hour energy metabolism in healthy, young, lean individuals.

Research Method and Procedures:Thirty‐one male and female subjects consumed 3 × 250‐mL servings of a beverage containing green tea catechins, caffeine, and calcium for 3 days in a single‐center, double‐blind, placebo‐controlled, cross‐over design study. On the 3rd day, 23‐hour energy metabolism, extrapolated to 24‐hour, was measured in a calorimeter chamber. Blood pressure and heart rate were measured, and total day and night urines were analyzed for urea and catecholamine excretion.

Results:Twenty‐four‐hour energy expenditure (EE) and 24‐hour fat oxidation were lower in women than in men (p< 0.0001 andp< 0.015, respectively). Although there were no treatment or treatment/gender effects on substrate oxidation, treatment increased 24‐hour EE by 106 ± 31 kcal/24 hours (p= 0.002), equivalent to 4.7 ± 1.6 kcal/h (day;p= 0.005) and 3.3 ± 1.5 kcal/h (night;p= 0.04). No significant differences were observed in hemodynamic parameters.

Discussion:The present study provides evidence that consumption of a beverage containing green tea catechins, caffeine, and calcium increases 24‐hour EE by 4.6%, but the contribution of the individual ingredients cannot be distinguished. Although this increase is modest, the results are discussed in relation to proposed public health goals, indicating that such modifications are sufficient to prevent weight gain. When consumed regularly as part of a healthy diet and exercise regime, such a beverage may provide benefits for weight control.
Body Composition of Obese Subjects by Air Displacement Plethysmography: The Influence of Hydration
Authors: Le Carvennec Marie , Fagour Cédric , Adenis‐Lamarre Emilie , Perlemoine Caroline , Gin Henri , Rigalleau Vincent
Published: July 2008

Objective: We investigated whether air displacement plethysmography (ADP) could detect small changes in body composition of obese subjects with alterations in hydration.

Research Methods and Procedures: Ten obese subjects (mean BMI, 39.3 ± 2.8 kg/m2) entered the ADP chamber without and with oil (1, 2, or 4 liters), water (1, 2, or 4 liters), or mixed (1 liter oil + 1 liter water or 2 liters oil + 2 liters water) loads. Real and measured changes in body composition were compared by regression analysis and Bland‐Altman procedures.

Results: The ADP‐measured changes in volume did not differ from the real values and were strongly correlated with them (r = 0.98). In all cases, loads of differing composition and similar volume led to different values of fat, fat‐free mass, and percentage fat. Water was detected as increased fat‐free mass only with loads of ≥2 liters, most of the water being falsely detected as increased fat mass. The observed changes were correlated with the real ones for fat mass (r = 0.68; p < 0.0001), fat‐free mass (r = 0.66; p < 0.0001), and percentage fat (r = 0.61; p < 0.0001), but fat mass changes were overestimated by ∼1 kg, and fat‐free mass changes were underestimated by ∼1 kg. This underestimation increased with the highest water loads, as shown by the Bland‐Altman plot (r = −0.27; p < 0.05). Percentage fat changes were overestimated by 0.8% (p < 0.001); the magnitude of the error was correlated with the weight of the water load (r = 0.62; p < 0.0001).

Discussion: ADP accurately measures changes in body volume, discriminating small changes in body composition. It overestimates changes in adiposity, as most of the increased hydration is detected as an enlarged fat mass.
Recognition of Childhood Overweight during Health Supervision Visits: Does BMI Help Pediatricians?
Authors: Barlow Sarah E. , Bobra Sonal R. , Elliott Michael B. , Brownson Ross C. , Haire‐Joshu Debra
Published: July 2008

Objective: To assess, in diverse pediatric practices, the frequency of overweight/obesity (OW/OB) identification during health supervision visits and its association with BMI curve use.

Research Methods and Procedures: Pediatricians in public and private practice in St. Louis, MO, participated in a study of the care of chronic conditions during health supervision visits. Requested information from 30 visits per pediatrician of children 6 to 17 years of age included the visit note, the growth chart, and a one‐page questionnaire about patient demographics and visit content. Pediatricians indicated the presence and discussion of common chronic conditions, including OW/OB. Identification was compared with patient BMI category, and associations between identification and patient and visit characteristics, including BMI curve use, were examined.

Results: Twenty‐one (40%) of contacted pediatricians returned information from 557 visits. Pediatricians identified OW/OB in 27% of children with a BMI at the 85th to 94th percentile and 86% of children with a BMI at or above the 95th percentile. Identification was higher in adolescents but was not associated with patient sex or race, practice setting, insurance type, or visit length. Only 41% of growth charts were current, and 6.1% had BMI plotted. BMI plotting was associated with OW/OB identification when the BMI was at the 85th to 94th percentile but not when the BMI was at or above the 95th percentile. After controlling for BMI percentile, OW/OB identification was significantly associated with diet counseling (odds ratio, 7.46; 95% confidence interval, 3.42 to 16.24) and exercise counseling (odds ratio, 5.57; 95% confidence interval, 2.61 to 11.90).

Discussion: Despite low BMI curve use, pediatricians recognized most overweight/obese children with a BMI at or above the 95th percentile. BMI plotting may increase recognition in mildly overweight children.
Birthplace, Years of Residence in the United States, and Obesity Among Mexican‐American Adults
Authors: Barcenas Carlos H. , Wilkinson Anna V. , Strom Sara S. , Cao Yumei , Saunders Katherine C. , Mahabir Somdat , Hernández‐Valero María A. , Forman Michele R. , Spitz Margaret R. , Bondy Melissa L.
Published: July 2008

Objective: To evaluate the association between birthplace (Mexico or U.S.) and obesity in men and women and to analyze the relationship between duration of U.S. residency and prevalence of obesity in Mexican immigrants.

Research Methods and Procedures: We used cross‐sectional data from 7503 adults of Mexican descent residing in Harris County, TX, to evaluate the relationships among BMI, birthplace, and years of residency in the U.S., controlling for demographic characteristics, physical activity level, and acculturation level.

Results: U.S.‐born adults had an increased risk (between 34% and 65%) of obesity compared with their Mexican‐born counterparts. After controlling for recognized confounders and risk factors, this association was maintained in the highly acculturated only. Among highly acculturated obese U.S.‐born men, 6% of the cases were attributable to the joint effect of birthplace and acculturation; in women, this proportion was 25%. Among Mexican‐born women, there was an increasing trend in mean BMI with increasing duration of residency in the U.S. Compared with immigrants who had lived in the U.S. for <5 years, Mexican‐born women who had resided in the U.S. for ≥15 years had an adjusted BMI mean difference of 2.12 kg/m2 (95% confidence interval, 1.53–2.72).

Discussion: Mexican‐born men and women have a lower risk of obesity than their U.S.‐born counterparts, but length of U.S. residency among immigrants, especially in women, is directly associated with risk of obesity. Development of culturally specific interventions to prevent obesity in recent immigrants may have an important public health effect in this population.
Effect of Retirement on Eating Out and Weight Change: An Analysis of Gender Differences
Authors: Chung Sukyung , Popkin Barry M. , Domino Marisa E. , Stearns Sally C.
Published: July 2008

Objectives: The objectives were to understand how the retirement decisions of older Americans influence household food consumption patterns by gender and, in turn, to examine the impact of the change in food consumption on weight.

Research Methods and Procedures: This study used five waves of the Health and Retirement Study (1992 to 2002; n = 28,117). Participants were 50 to 71 years old during the study period. We used longitudinal regression analyses controlling for health events, spousal factors, socioeconomic factors, and individual fixed effects over time.

Results: Retirement of the individual and of his/her spouse reduced the individual's monthly spending on eating out by $10 and $7 on average, respectively, but did not change household spending on food at home. The wife's, but not the husband's, retirement decreased the spouse's spending on eating out by $13/mo. Spending on eating out was a significant but weak (0.003BMI/$) predictor of weight gain.

Discussion: The decrease in spending on eating out after retirement, particularly women's, suggests that people eat out less when they have more time for food preparation at home. However, increases in other risks of weight gain with retirement, such as physical inactivity, could counteract the effects of eating out less.
Varying Patterns of BMI Increase in Sex and Birth Cohorts of Korean Adults
Authors: Kwon Jin‐Won , Song Yun‐Mi , Sung Joohon , Sohn YeoJin , Cho Sung‐Il
Published: July 2008

Objective: The Korean population has recently experienced a rapid increase in obesity associated with lifestyle changes arising from economic growth. We examined trends in BMI by analyzing sex‐specific birth cohorts using 3,400,727 measurements from 1,662,477 Korean adults.

Research Methods and Procedures: Birth cohort data were collected from the employees of government organizations and schools and their dependents, 20 to 65 years of age, who participated in health examinations provided by the Korean National Health Insurance Corporation in 1992, 1996, and 2000.

Results: The prevalence of obesity (BMI ≥ 30 kg/m2) was 0.8% among men and 0.3% among women in 1992, but by 2000, it had increased 2.5‐fold to 2.0% in men and 2.3‐fold to 0.7% in women. Over the 8‐year period, the mean BMI increased 0.8 kg/m2 in men and 0.3 kg/m2 in women. The rate of BMI increase over the 8 years varied markedly among the sex‐specific birth cohorts, with the steepest slopes representing the youngest men (0.2 kg/m2 per year).

Discussion: National health promotion activities should target younger men to prevent an increase in obesity‐related morbidity and mortality.
Burden of Infection and Fat Mass in Healthy Middle‐aged Men
Authors: Fernández‐Real José‐Manuel , Ferri Maria‐José , Vendrell Joan , Ricart Wifredo
Published: July 2008

Objective: Our aim was to study the effect of exposure to four infections on fat mass.

Research Methods and Procedures: This was a cross‐sectional study of healthy middle‐aged men from the general population (n = 74). Each study subject's serum was tested for specific IgG class antibodies against herpes simplex virus (HSV)‐1, HSV‐2, enteroviruses, and Chlamydia pneumoniae through the use of quantitative in vitro enzyme‐linked immunosorbent assays (ELISAs). A total pathogen burden score based on these seropositivities [Quantitative Seropositivity Index (QSI)] was constructed. Fat mass was measured by bioelectrical impedance.

Results: We observed significant relationships between the HSV‐1 titer and fat mass and percentage fat mass. The associations were stronger when considering the infection burden. The QSI was significantly associated with fat mass (r = 0.30, p = 0.009) and percentage fat mass (r = 0.27, p = 0.01). Those subjects in the highest tertile of fat mass showed significantly higher QSI (259.5 ± 74.1 vs. 206.9 ± 78.2, p = 0.007). In subjects that were seropositive for Enteroviruses, the relationship between the QSI and fat mass was strengthened (r = 0.51, p = 0.02). In a multivariate regression analysis, the QSI, independently of age and C‐reactive protein, contributed to 9% of fat mass variance.

Discussion: Pathogen burden showed an association with fat mass. Subjects with increased fat mass could be more susceptible to developing multiple infections resulting in a chronic low‐grade inflammation. We can not exclude the possibility that exposure to multiple infections leads to increased fat mass.
Twenty‐four‐hour Ghrelin Is Elevated after Calorie Restriction and Exercise Training in Non‐obese Women
Authors: Leidy Heather J. , Dougherty Kelly A. , Frye Brian R. , Duke Kristin M. , Williams Nancy I.
Published: July 2008

Objective: The purpose of this study was to determine whether chronic energy deficiency achieved with caloric restriction combined with exercise is associated with changes in the 24‐hour profile of ghrelin in non‐obese, pre‐menopausal women.

Research Methods and Procedures: Twelve non‐obese (BMI = 18 to 25 kg/m2), non‐exercising women (age, 18 to 24 years) were randomly assigned to a non‐exercising control group or a diet and exercise group. The 3‐month diet and exercise intervention yielded a daily energy deficit of −45.7 ± 12.4%. Serial measurements were made of body composition, energy balance, and feelings of fullness. Repeated blood sampling over 24 hours to measure ghrelin occurred before and after the study.

Results: Significant decreases in body weight, body fat, and feelings of fullness were observed in only the energy‐deficit group (p < 0.05); significant changes in the following ghrelin features were found in only the deficit group (p < 0.05): elevations in baseline (+353 ± 118 pg/mL), lunch peak (+370 ± 102 pg/mL), dinner peak (+438 ± 149 pg/mL), nocturnal rise (+269 ± 77 pg/mL), and nocturnal peak (+510 ± 143 pg/mL). In addition, we found a larger dinner decline (−197 ± 52 pg/mL) and negative correlations between changes in the ghrelin dinner profile and changes in body weight (R = 0.784), 24‐hour intake (R = 0.67), energy deficiency (R = 0.762), and feelings of fullness (R = 0.648; p < 0.05).

Discussion: Changes in ghrelin concentrations across the day after weight loss are closely associated with other physiological adaptations to energy deficiency, further supporting the role of ghrelin as a countermeasure to restore energy balance.
Resistin Polymorphisms Are Associated with Muscle, Bone, and Fat Phenotypes in White Men and Women
Authors: Pistilli Emidio E. , Gordish‐Dressman Heather , Seip Richard L. , Devaney Joseph M. , Thompson Paul D. , Price Thomas B. , Angelopoulos Theodore J. , Clarkson Priscilla M. , Moyna Niall M. , Pescatello Linda S. , Visich Paul S. , Zoeller Robert F. , Hoffman Eric P. , Gordon Paul M.
Published: July 2008

Objective: The biological function of resistin (RST) is unknown, although it may have roles in obesity, diabetes, and insulin resistance. The objective of this study was to examine the effects of single nucleotide polymorphisms (SNPs) in the human RST gene on muscle, bone, and adipose tissue phenotypes and in response to resistance training (RT).

Research Methods and Procedures: Subjects were white and consisted of strength (n = 482) and size (n = 409) cohorts who had not performed RT in the previous year. Subjects completed 12 weeks of structured, unilateral upper arm RT aimed at increasing the size and strength of the non‐dominant arm, using their dominant arm as an untrained control. Strength measurements were taken pre‐ and post‐12‐week RT and consisted of elbow flexor isometric strength and one‐repetition maximum during a biceps curl using free weights. Whole muscle, subcutaneous fat, and cortical bone volumes were measured by magnetic resonance imaging. Six RST SNPs were identified. Analysis of covariance was used to test for effects of the SNPs on pre‐ and post‐muscle strength and whole muscle, fat, and bone volumes independent of gender, age, and body weight.

Results: Five RST SNPs (−537 A>C, −420 C>G, 398 C>T, 540 G>A, 980 C>G) were associated with measured phenotypes among subjects when stratified by BMI (<25, ≥25 kg/m2). Several gender‐specific associations were observed between RST SNPs and phenotypes among individuals with a BMI ≥ 25. Conversely, only two associations were observed among individuals with a BMI < 25.

Discussion: These data support previous identified associations of RST with adipose tissue and demonstrate additional associations with bone and skeletal muscle that warrant further investigation.
Circadian Rhythms and the Regulation of Metabolic Tissue Function and Energy Homeostasis
Authors: Zvonic Sanjin , Floyd Z. Elizabeth , Mynatt Randall L. , Gimble Jeffrey M.
Published: July 2008

Circadian oscillators play an indispensable role in the coordination of physiological processes with the cyclic changes in the physical environment. A significant number of recent clinical and molecular studies suggest that circadian biology may play an important role in the regulation of adipose and other metabolic tissue functions. In this discussion, we present the hypothesis that circadian dysfunction may be involved in the pathogenesis of obesity, type 2 diabetes, and the metabolic syndrome.
Gap‐Junctional Communication Is Required for Mitotic Clonal Expansion during Adipogenesis
Authors: Yanagiya Takahiro , Tanabe Atsushi , Hotta Kikuko
Published: July 2008

Objective: Gap‐junctional communication (GJC) plays critical roles in cell growth and differentiation. Several studies have demonstrated the involvement of GJC in myogenesis and osteogenesis; however, the role of GJC in adipogenesis has not been fully studied. Thus, we investigated the role of GJC in adipogenesis.

Research Methods and Procedures: 3T3‐L1 preadipocytes were differentiated in the presence of gap junction inhibitor, 18‐α‐glycyrrhetinic acid (AGA), and accumulation of cytoplasmic triglycerides was measured. 3T3‐L1 cells were transfected with 100 nM small interfering RNA duplexes targeting connexin (Cx) 43. The mRNA levels of CCAAT/enhancer‐binding protein (C/EBP) α, peroxisome proliferator‐activated receptor γ, glucose transporter 4, C/EBPβ, and Cx43 were measured by real‐time polymerase chain reaction. The protein levels of C/EBPβ were quantitated by Western blotting. The cell proliferation was measured by counting cell numbers, and DNA synthesis was measured by bromodeoxyuridine incorporation.

Results: AGA inhibited adipocyte differentiation dose‐dependently. The lipid accumulation and the mRNA levels of C/EBPα, peroxisome proliferator‐activated receptor γ, and glucose transporter 4 were markedly reduced in AGA‐treated adipocytes. The mRNA levels of C/EBPβ did not decrease; however, C/EBPβ [liver‐enriched transcriptional activator protein (LAP)] expression and the C/EBPβ (LAP)‐to‐C/EBP [liver‐enriched transcriptional inhibitory protein (LIP)] ratio were reduced by AGA treatment. The increase in both cell number and DNA synthesis, which occurs during mitotic clonal expansion, was reduced by AGA in a dose‐dependent fashion. The major component of gap junctions in 3T3‐L1 cells was Cx43. Down‐regulation of Cx43 using small interfering RNA reduced the expression of C/EBPβ (LAP) and inhibited adipogenesis.

Discussion: Our data suggest that GJC plays some important roles in adipogenesis through inhibiting mitotic clonal expansion and modulating C/EBPβ (LAP) expression.
Effects of Post‐absorptive and Postprandial Exercise on Glucoregulation in Metabolic Syndrome
Authors: Derave Wim , Mertens Ann , Muls Erik , Pardaens Karel , Hespel Peter
Published: July 2008

Objective: The aim of this study was to investigate the effects of an acute exercise bout in the morning in the post‐absorptive or postprandial state on the glycemic and insulinemic response to three standardized meals throughout the day. It is hypothesized that post‐absorptive exercise enhances fat oxidation rate during exercise and thereafter attenuates the glucose and insulin response to subsequent meals.

Research Methods and Procedures: Seven sedentary males with metabolic syndrome (age, 45 ± 11 years; BMI, 34 ± 3 kg/m2) were studied in a crossover design comparing three conditions: no exercise, postprandial and post‐absorptive exercise (at ∼60% of the individual V̇O2max for 45 minutes). Substrate use was evaluated by indirect calorimetry during exercise. Venous blood samples were taken at regular (30‐ to 60‐minute) intervals throughout the day, and glucose, insulin, and triglyceride concentrations were determined.

Results: During exercise, a higher fat oxidation rate was observed in the post‐absorptive than the postprandial state. The glycemic response to a standardized high‐carbohydrate breakfast was lower when exercising after breakfast than when exercising before breakfast. There was no effect of either exercise mode on glucose and insulin response to lunch and supper.

Discussion: Post‐absorptive exercise has the advantage of promoting fat use, whereas postprandial exercise can attenuate the glycemic response to breakfast. Neither exercise mode acutely induces improved glucoregulation later during the day. The impact of meal timing on the effects of regular exercise training on glycemic control in this population remains to be studied.
Effects of Age on Children's Intake of Large and Self‐selected Food Portions
Authors: Fisher Jennifer Orlet
Published: July 2008

Objective: Whether developmental periods exist in which children become particularly sensitive to environmental influences on eating is unclear. This research evaluated the effects of age on intake of large and self‐selected portions among children 2 to 9 years of age.

Research Methods and Procedures: Seventy‐five non‐Hispanic white children 2 to 3, 5 to 6, and 8 to 9 years of age were seen at a dinner meal in reference, large, and self‐selected portion size conditions in which the size of an entrée was age‐appropriate, doubled, and determined by the child, respectively. Weighed food intake data were collected. Entrée bite size and bite frequency were assessed. Height and weight measurements were obtained.

Results: The effect of age on children's intake of the large portion was not significant. Entrée consumption was 29% greater (p < 0.001) and meal energy intake was 13% greater (p < 0.01) in the large portion condition than in the reference condition. Increases in entrée consumption were attributable to increases in average bite size (p < 0.001). Neither child weight nor maternal weight predicted children's intake of large portions. Self‐selection resulted in decreased entrée (p < 0.05) and meal energy (p < 0.01) only among those children who ate more when served the large portion.

Discussion: The results of this research confirm that serving large entrée portions promotes increased intake at meals among 2‐ to 9‐year‐old children. These findings suggest that any age‐related differences in children's response to large portions are likely to be smaller than previously suspected.
Intake Compensates for Resting Metabolic Rate Variation in Female C57BL/6J Mice Fed High‐fat Diets
Authors: Johnston Sarah L. , Souter Donna M. , Tolkamp Bert J. , Gordon Iain J. , Illius Andrew W. , Kyriazakis Ilias , Speakman John R.
Published: July 2008

Objective: The literature is divided over whether variation in resting metabolic rate (RMR) is related to subsequent obesity. We set out to see whether the effect of RMR on weight gain in mice could be revealed with high‐fat feeding.

Research Methods and Procedures: Female C57BL/6J mice received a low‐ (10 kcal%fat n = 47), medium‐ (45 kcal%fat n = 50), or high‐fat diet (60 kcal%fat n = 50) for 12 weeks. Pre‐treatment RMR was measured by indirect calorimetry. Body composition was estimated using DXA before and after treatment.

Results: Mice on the high‐fat diet gained 39% of body mass, whereas control animals gained 3.5%. There was no interaction between RMR and dietary type on weight gain, and there was no association between weight gain and RMR for any of the treatments. RMR accounted for 2.4% of the variation in pre‐treatment food intake corrected for initial body mass; however, the gradient of this relationship indicated that variations in RMR were, on average, compensated for by adjustments in food intake.

Discussion: Individual variations in RMR did not predispose mice to weight gain independent of the dietary treatment. Deviations from the relationship between RMR and food intake were not associated with weight gain. This suggests that variations in energy expenditure, caused by RMR and physical activity, are closely linked to dietary intake, and, therefore, well compensated. Individual variations in the strength of this association may underpin individual variability in the responses to diet.
Effect of Obesity on Inpatient Rehabilitation Outcomes after Total Hip Arthroplasty
Authors: Vincent Heather K. , Weng Jenpin P. , Vincent Kevin R.
Published: July 2008

Objective: This study examined whether obesity affected inpatient rehabilitation outcomes after total hip arthroplasty (THA).

Research Methods and Procedures: This was a retrospective, comparative study conducted using a computerized medical database derived from THA patients at a university‐affiliated rehabilitation hospital (data from 2002 to 2005). Patients were divided into four brackets based on BMI: non‐obese (<25 kg/m2), overweight (25 to 29.9 kg/m2), moderate obesity (30 to 39.9 kg/m2), and severe obesity (≥40 kg/m2). All patients completed an interdisciplinary inpatient rehabilitation program after THA. Functional independence measure (FIM) scores, length of stay (LOS), FIM efficiency scores (FIM/LOS), hospital charges, and discharge disposition location were collected.

Results: FIM scores improved from admission to discharge similarly in all groups (25 to 29.5 points). However, FIM efficiency, LOS, and total charges were curvilinearly related with BMI (all p < 0.05). Total hospital charges were highest in the severely obese group compared with the overweight group (p < 0.05). Non‐homebound discharge disposition rates were lower in non‐obese (13.1%) and severely obese groups (10.5%).

Discussion: Elevated BMI does not prevent FIM gains in THA patients during inpatient rehabilitation. However, BMI is related with FIM efficiency, LOS, and hospital charges in a curvilinear fashion. Severely obese patients can achieve physical improvements but at a lower efficiency and greater cost.
Associations Between the Home Food Environment and Obesity‐promoting Eating Behaviors in Adolescence
Authors: Campbell Karen J. , Crawford David A. , Salmon Jo , Carver Alison , Garnett Sarah P. , Baur Louise A.
Published: July 2008

Objective: This study examines relationships between multiple aspects of the home food environment and obesity‐promoting characteristics of 12‐ to 13‐year‐old adolescents' diets, specifically frequency of consumption of high‐energy fluids, sweet snacks, savory snacks, and take‐out foods.

Research Methods: This was a cross‐sectional study including 347 adolescents 12 to 13 years of age and their parents. Data were collected via self‐completed surveys. The adolescents' diets were assessed using a Food Frequency Questionnaire derived from existing age‐appropriate National Nutrition Survey data. An extensive range of domains within the home food environment were assessed. Bivariate linear regression analyses were run split by gender. Forced entry multiple linear regression analyses (adjusting for all variables significant in bivariate analyses as well as for maternal education) were also performed, stratified by the sex of the child.

Results: The influence of mothers, either as models for eating behaviors or as the providers of food, was pervasive. Mothers' intake of high‐energy fluids (p = 0.003), sweet snacks (p = 0.010), savory snacks (p = 0.008), and take‐out food (p = 0.007) was positively associated with boys' intake of all these foods. In addition, mothers' intake of high‐energy fluids was positively associated with daughters' consumption of these drinks (p = 0.025). Furthermore, availability of unhealthy foods at home was positively associated with girls' sweet snack (p = 0.001), girls' savory snack (p < 0.001), boys' savory snack (p = 0.002), and, in the bivariate analyses, girls' high‐energy fluid consumption (p = 0.002).

Discussion: This study of home food environment influences on adolescent diet highlights the pervasive influence of mothers in determining adolescents' obesity‐promoting eating, providing direction for obesity prevention strategies and future research.
Effect of Marked Weight Loss on Adiponectin Gene Expression and Plasma Concentrations
Authors: Coughlin Carrie C. , Finck Brian N. , Eagon J. Christopher , Halpin Valerie J. , Magkos Faidon , Mohammed B. Selma , Klein Samuel
Published: July 2008

Objective: Adiponectin is the most abundant protein secreted by adipose tissue and is inversely associated with adiposity and insulin resistance. The aim of this study was to evaluate the hypothesis that marked weight loss, induced by gastric bypass surgery (GBS), would increase adiponectin gene expression in both upper and lower subcutaneous body fat and increase plasma adiponectin concentration.

Research Methods and Procedures: Adiponectin subcutaneous abdominal and femoral adipose tissue gene expression, determined by using quantitative reverse transcriptase‐polymerase chain reaction, and adiponectin plasma concentrations, determined by using enzyme‐linked immunosorbent assay, were evaluated in six extremely obese women (BMI = 57.1 ± 4.1 kg/m2) before and 1 year after GBS.

Results: After GBS, subjects lost 36 ± 5% of their initial body weight and showed increased insulin sensitivity, manifested by a marked decrease in homeostasis model assessment of insulin resistance from 10.7 ± 4.1 to 1.4 ± 0.3 (p < 0.05). Adiponectin gene expression increased 8‐ to 15‐fold in subcutaneous abdominal and femoral adipose tissues (p < 0.05). Plasma adiponectin concentrations increased from 5.2 ± 0.9 to 8.4 ± 1.2 μg/mL (p < 0.05).

Discussion: These data show that marked weight loss induced by GBS increases adiponectin gene expression in both upper‐ and lower‐body subcutaneous fat. The increase in adipose tissue adiponectin production resulted in an increase in plasma adiponectin concentrations, which likely contributed to the decrease in insulin resistance observed after weight loss.
Chronic Tachygastrial Electrical Stimulation Reduces Food Intake in Dogs
Authors: Zhang Jing , Xu Xiaohong , Chen Jiande D.Z.
Published: July 2008

Objective: Tachygastria is known to be associated with gastric hypomotility. This study investigated the effect of tachygastrial electrical stimulation (TES) on food intake and its effects on gastric motility.

Research Methods and Procedures: Five experiments were performed to study the effects of TES on gastric slow waves, gastric tone, accommodation, and antral contractions, gastric emptying, acute food intake, and chronic food intake in dogs.

Results: TES at tachygastrial frequencies induced tachygastria and reduced normal slow waves. TES significantly reduced gastric tone or induced gastric distention, impaired gastric accommodation, and inhibited antral contractions. TES significantly delayed gastric emptying. Acute TES reduced food intake but did not induce any noticeable symptoms. Chronic TES resulted in a 20% reduction in food intake, and the effect of TES was found to be related to specific parameters.

Discussion: TES at the distal antrum results in a significant reduction in food intake in dogs, and this inhibitory effect is probably attributed to TES‐induced reduction in proximal gastric tone, gastric accommodation, antral contractility, and gastric emptying. These data suggest a therapeutic potential of the specific method of TES for obesity.
DXA Measurements Confirm that Parental Perceptions of Elevated Adiposity in Young Children are Poor
Authors: Miller Jody C. , Grant Andrea M. , Drummond Bernadette F. , Williams Sheila M. , Taylor Rachael W. , Goulding Ailsa
Published: July 2008

Objective: To compare parental assessments of child body weight status with BMI measurements and determine whether children who are incorrectly classified differ in body composition from those whose parents correctly rate child weight. Also to ascertain whether children of obese parents differ from those of non‐obese parents in actual or perceived body weight.

Research Methods and Procedures: Weights, heights, BMI, and waist girths of New Zealand children ages 3 to 8 years were determined. Fat mass, fat percentage, and lean mass were measured by DXA (n = 96). Parents classified child weight status as underweight, normal‐weight, slightly overweight, or overweight. Centers for Disease Control and Prevention 2000 percentiles of BMI were used.

Results: Parents underestimated child weight status. Despite having 83% more fat mass than children with BMI values below the 85th percentile, only 7 of 31 children with BMI values at or above the 85th percentile were rated as slightly overweight or overweight. In the whole sample, participants whose weight status was underestimated by parents (40 of the 96 children) had l9% less fat mass but similar lean mass as children whose weight status was correctly classified. However, children of obese and non‐obese parents did not differ in body composition or anthropometry, and obese parents did not underestimate child weight more than non‐obese parents.

Discussion: Because parents underestimate child weight, but BMI values at or above the 85th percentile identify high body fat well, advising parents of the BMI status of their children should improve strategies to prevent excessive fat gain in young children.
Race and Gender Differences in the Association of Dieting and Gains in BMI among Young Adults
Authors: Field Alison E. , Aneja Parul , Austin S. Bryn , Shrier Lydia A. , De Moor Carl , Gordon‐Larsen Penny
Published: July 2008

Objective: To assess the relationship between dieting and subsequent weight change and whether the association varies by gender or race/ethnicity.

Research Methods and Procedures: Male (n = 4100) and female (n = 4302) participants in the National Longitudinal Study of Adolescent Health who provided information on weight and height at baseline and two follow‐up assessments and were not missing information on weight control strategies or race were studied. Generalized estimating equations were used to assess whether dieting to lose or maintain weight at Wave I or II predicted BMI (kg/m2) change between adolescence and young adulthood (Wave II to III). Analyses were stratified by gender and took sampling weights and clustering into account.

Results: At Wave I, the mean age of the participants was 14.9 years. Approximately 29.3% of female participants and 9.8% of male participants reported dieting in Wave I or II. Fewer African Americans than whites (6.2% vs. 10.0% and 25.5% vs. 31.2%, p = 0.007 and p = 0.02, among males and females, respectively) reported dieting. Between Waves II and III, participants gained on average 3.3 kg/m2. Independent of BMI gain during adolescence (Waves I to II), female participants who dieted to lose or maintain weight during adolescence made larger gains in BMI during the 5 years between Waves II and III (mean additional gain, 0.39 kg/m2; 95% confidence interval, 0.08 to 0.71) than their nondieting peers. The association was not significant among the male participants. The association was largest among African‐American female participants.

Discussion: The results suggest that not only is dieting to lose weight ineffective, it is actually associated with greater weight gain, particularly among female adolescents. Female African‐American dieters made the largest BMI gains.
Ethnic Differences in Lifestyle and Overweight in The Netherlands
Authors: Cornelisse‐Vermaat Judith R. , van den Brink Henriëtte Maassen
Published: July 2008

Objective: To study the effects of lifestyle variables and socioeconomic status on overweight among native Dutch and immigrants in The Netherlands.

Research Methods and Procedures: Data were used from a survey sample (N = 2551) of native Dutch and immigrant respondents (Surinamese/Antilleans, Turks, and Moroccans). BMI was calculated using self‐reported weight and height. Lifestyle variables such as modern food habits (take‐out food and eating out) and participating in sports were included, as well as socioeconomic and demographic background variables. Bivariate and ordinary least squares analyses were performed to study BMI and the determinants of overweight among the different groups.

Results: All immigrant groups had a higher prevalence of overweight than the Dutch, except Moroccans. Men were overweight more frequently than women. Take‐out food, eating out, and fresh vegetables were related to a decrease in BMI, whereas convenience foods were related to an increase in BMI. For ready‐to‐eat meals, the results were mixed. In all groups, age was associated with a higher BMI, and a higher level of education was associated with a lower BMI. Immigrants participated in sports less frequently than native Dutch people.

Discussion: One percent to 5% of the total public health costs can be attributed to costs for overweight‐related diseases. Public health policies should aim at stimulating healthy lifestyles and discouraging bad food habits through higher taxes on high‐calorie foods. In particular, Dutch immigrants should be encouraged to lose weight, because they have a higher risk for overweight‐related diseases.
Circadian Expression of Genes Regulating Food Intake
Authors: Stütz Adrian M. , Staszkiewicz Jaroslaw , Ptitsyn Andrey , Argyropoulos George
Published: July 2008

Objective: The Agouti‐related protein (AgRP), neuropeptide Y (NPY), proopiomelanocortin (POMC), cocaine and amphetamine‐regulated transcript (CART), Orexin, melanin concentrating hormone (MCH), leptin, and its hypothalamic receptor (LR) are key regulators of food intake and energy homeostasis. In the present study, we examined the circadian expression profiles of these genes.

Research Methods and Procedures: We used quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR) to measure mRNA levels, spectral analysis to evaluate periodicity, and correlation analysis to examine for associations with diurnal food intake.

Results: No gene in particular stood out as a strong candidate, but the overall circadian expression profiles of leptin and its hypothalamic receptor came close to statistically and graphically resembling the diurnal feeding behavior of mice. In mathematical terms, adrenal AgRP exhibited strong circadian expression and had the highest correlation with food intake, followed by leptin. Yet its highest point of expression occurred 8 hours after nocturnal food intake had peaked, suggesting that adrenal AgRP could not play a direct role in the initiation of nocturnal feeding; neither did hypothalamic AgRP, NPY, POMC, CART, Orexin, or MCH.

Discussion: These data show that ad libitum feeding in mice is influenced by complex central and peripheral circuits involving orexigenic and anorectic agents of which leptin and its hypothalamic receptor could play more prevalent roles.