Total Body Fat (total + body_fat)

Distribution by Scientific Domains

Selected Abstracts

Changes in serum leptin concentrations in overweight Japanese men after exercise

N. Miyatake
Aim:, To investigate the link between serum leptin concentrations and exercise. Design:, Cross-sectional and longitudinal studies of an exercise intervention. Subjects:, 110 Japanese overweight men aged 32,59 years were recruited. At baseline, the average body mass index (BMI) was 28.5 2.5 kg/m2. From this group, we used data of 36 overweight men (BMI, 28.9 2.3) for a 1-year exercise programme. Measurements:, Leptin was measured at baseline and after 1 year. Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography (CT) scanning at umbilical levels. Anthropometric parameters, aerobic exercise level, muscle strength and flexibility were also investigated at baseline and after 1 year. Results:, In the first analysis, using cross-sectional data, leptin was significantly correlated with total body fat (r = 0.760, p < 0.01), V (r = 0.383, p < 0.01) and S (r = 0.617, p < 0.01) areas. In the second analysis, using longitudinal data, leptin was significantly reduced after 1 year (pre 6.7 4.0 ng/ml vs. post 5.1 3.1 ng/ml, p < 0.01). Results showed that steps per day were increased, and aerobic exercise level, weight-bearing index (WBI) and insulin resistance were significantly improved. Although, there was a positive correlation between , leptin(positive changes in leptin after 1 year) and anthropometric measurements such as , body weight, , BMI and , body fat, leptin/body weight, leptin/BMI and leptin/body fat ratios were significantly reduced during exercise intervention. Conclusion:, The present study indicated exercise significantly lowers serum leptin concentrations, and thus it may improve the leptin resistance observed in overweight Japanese men. [source]

The prevalence of lipodystrophy in an ambulant HIV-infected population: it all depends on the definition

HIV MEDICINE, Issue 3 2001
VM Carter
Objectives This study's objective was to determine the prevalence of body shape changes and metabolic abnormalities in an ambulant population with HIV infection. Three different definitions of lipodystrophy were used to assess these changes. Patients' anthropometric measures and dual-energy X-ray absorptiometry (DEXA) scans were compared in order to estimate fat distribution in this population. We sought to evaluate potential predictors for lipodystrophy according to each of the three definitions. Methods We performed a cross-sectional study in the outpatient clinic of a tertiary referral hospital in Melbourne, Australia. We enrolled a total of 167 HIV-infected ambulatory patients over 3 months in mid-1998. Data on 159 males, 149 of whom were receiving triple combination antiretroviral therapy, were evaluated. Anthropometric measures, clinical examination, self-report of body shape changes, biochemical measures and DEXA scan were used to assess lipodystrophy and risk factors for cardiovascular disease. Patients described body shape changes in the face, trunk, arms and legs. Laboratory parameters measured included fasting triglyceride (TG), cholesterol, high-density lipoproteins (HDL), glucose, insulin, CD4 cell count and plasma HIV RNA. Current and past antiretroviral therapies were ascertained. Results According to one proposed Australian national definition of lipodystrophy (LDNC), the prevalence of lipodystrophy in this population was 65%. This definition included an objective assessment with major and minor criteria. Patient-defined lipodystrophy (LDP), which involved a subjective assessment of thinning arms and legs and central adiposity, occurred in 19%. Patient-defined lipoatrophy (LAP), which involved a subjective assessment of thinning arms and legs without central adiposity, occurred in 21.3%. No change in body habitus was noted by 37% of the cohort. Hypercholesterolaemia was recorded in 44%, hypertriglyceridaemia in 52% and elevated insulin levels in 23%. Anthropometry was predictive of the per cent total body fat recorded by DEXA scan, but produced consistently lower values. In multivariate analysis, LDP and LAP were significantly associated with stavudine (d4T) use, while LAP was also associated with zidovudine (ZDV) treatment. There were no treatment associations with LDNC. Protease inhibitor (PI) exposure was associated with metabolic changes but not patient perceived body shape changes, while d4T and ZDV exposure was associated with increased triglycerides and reduced peripheral fat stores. Conclusions The prevalence of body shape changes in a single population varied depending on the definition applied. The LDNC definition overestimated body shape abnormalities in comparison with patient perception. LAP was associated with significantly lower fat stores measured by anthropometry and DEXA scan than those identified under the LDNC definition. In contrast to LDNC, LAP was associated with d4T exposure, nucleoside reverse transcriptase inhibitor (NRTI) and ZDV duration of use, but not PI use. Until a consensus definition for lipodystrophy is developed, including agreement on objective measurement and thresholds for abnormality, careful description of the individual components of the syndrome is required to enable cohort comparisons so that predictors of the syndrome can be assessed more accurately and outcome studies made feasible. [source]

Glucocorticoid Excess During Adolescence Leads to a Major Persistent Deficit in Bone Mass and an Increase in Central Body Fat

Veronica Abad
Abstract Endogenous Cushing's syndrome (CS) in children causes growth retardation, decreased bone mass, and increased total body fat. No prospective controlled studies have been performed in children to determine the long-term sequelae of CS on peak bone mass and body composition. A 15-year-old girl with Cushing disease (CD), and her healthy identical co-twin, were followed for 6 years after the CD was cured. At the 6-year follow-up both twins had areal bone mineral density (BMD) and body composition determined by dual-energy X-ray absorptiometry (DXA) and three-dimensional quantitative computed tomography (3DQCT). Z scores for height, weight, and body mass index (BMI) were ,2.3, ,0.8 and 0.2, and 1.2, 0.2, and ,0.6, in the twin with CD and her co-twin, respectively. In the twin with CD, areal BMD and bone mineral apparent density (BMAD) at different sites varied from 0.7 to 3 SD below her co-twin. Volumetric lumbar spine bone density Z score was ,0.75 and 1.0, and total body, abdominal visceral, and subcutaneous fat (%) was 42, 10, and 41 versus 26, 4, and 17 in the twin with CD and her co-twin, respectively. The relationship between total body fat and L2-L4 BMAD was inverse in the twin with CD (p < 0.05), which by contrast in her co-twin was opposite and direct (p < 0.001). In the twin with CD, despite cure, there was a persistent deficit in bone mass and increase in total and visceral body fat. These observations suggest that hypercortisolism (exogenous or endogenous) during adolescence may have persistent adverse effects on bone and fat mass. [source]

Long-term effects of calorie restriction on serum sex-hormone concentrations in men

AGING CELL, Issue 2 2010
Roberto Cangemi
Summary Calorie restriction (CR) slows aging and consistently reduces circulating sex hormones in laboratory animals. However, nothing is known regarding the long-term effects of CR with adequate nutrition on serum sex-hormone concentration in lean healthy humans. In this study, we measured body composition, and serum total testosterone, total 17-,-estradiol, sex hormone,binding globulin (SHBG), and dehydroepiandrosterone sulfate (DHEA-S) concentrations in 24 men (mean age 51.5 13 years), who had been practicing CR with adequate nutrition for an average of 7.4 4.5 years, in 24 age- and body fat,matched endurance runners (EX), and 24 age-matched sedentary controls eating Western diets (WD). We found that both the CR and EX volunteers had significantly lower body fat than the WD volunteers (total body fat, 8.7 4.2%; 10.5 4.4%; 23.2 6.1%, respectively; P = 0.0001). Serum total testosterone and the free androgen index were significantly lower, and SHBG was higher in the CR group than in the EX and WD groups (P , 0.001). Serum 17,-estradiol and the estradiol:SHBG ratio were both significantly lower in the CR and EX groups than in the WD group (P , 0.005). Serum DHEA-S concentrations were not different between the three groups. These findings demonstrate that, as in long-lived CR rodents, long-term severe CR reduces serum total and free testosterone and increases SHBG concentrations in humans, independently of adiposity. More studies are needed to understand the role of this CR-mediated reduction in sex hormones in modulating the pathogenesis of age-associated chronic diseases such as cancer and the aging process itself. [source]

Mini Nutritional Assessment in geriatric rehabilitation: Inter-rater reliability and relationship to body composition and nutritional biochemistry

Abstract Aim:, To determine the inter-rater reliability of the Mini Nutritional Assessment (MNA) and relationship with body composition and nutritional biochemistry among older Australians undergoing rehabilitation. Methods:, Thirty-eight adults aged ,65 years were prospectively and consecutively recruited from an Australian rehabilitation ward. Two dietitians independently administered the 18-item MNA to determine inter-rater reliability. MNA classifications (well nourished, at risk of malnutrition, malnourished) were compared with body composition (using dual-energy X-ray absorptiometry) and serum albumin. These analyses were also performed for the short-form version of the MNA (six items). Results:, In this cross-sectional study, inter-rater reliability of the 18-item MNA score, estimated by the intraclass correlation coefficient, was 0.833, while inter-rater reliability estimated by the weighted kappa index was 0.53. The two raters reached agreement on MNA classification for 26 of 38 cases (68%). Women classified as malnourished/at risk of malnutrition using the 18-item MNA had lower total body fat (11 kg vs 29 kg, P < 0.01) and per cent body fat (25% vs 40%, P < 0.01), compared with women classified as well nourished. Similar findings were not apparent for men, although men classified as malnourished/at risk of malnutrition had lower serum albumin (32 g/L vs 36 g/L, P = 0.04) compared with men classified as well nourished. Similar findings were evident for the short-form version of the MNA. Conclusion:, The MNA was found to be useful for identifying older women with lower body fat in the Australian rehabilitation setting. The 18-item MNA score has substantial inter-rater reliability, and fair inter-rater reliability when used according to the classifications. Inclusion of subjective and self-reported items in surveys can be problematic for optimal reliability as can the use of such items in a subject population that is experiencing rapid progress in recovery. [source]

Potential association between endogenous leptin and sympatho-vagal activities in young obese Japanese women

Tamaki Matsumoto
Leptin is an adipocyte-derived hormone that decreases food intake and increases energy expenditure through the activation of the sympathetic nervous system (SNS). Notwithstanding recent intensive research, the underlying physiological mechanism of leptin as well as the etiology of obesity in humans remains elusive. The present study attempted to investigate the potential association between endogenous circulating leptin and sympatho-vagal activities in age- and height-matched obese and nonobese healthy young women. Plasma leptin concentrations were measured by radioimmunoassay. The autonomic nervous system activity was assessed during the resting condition by means of a recently devised power spectral analysis of heart rate variability, which serves to identify three separate frequency components, very low (VLO), low (LO), and high (HI). Plasma leptin concentrations were greater in the obese than in the control group (45.7 5.89 vs. 11.2 1.10 ng ml,1, P < 0.01). As to the contribution of endogenous leptin to SNS activity, both the ratios of the VLO frequency component reflecting thermoregulatory sympathetic function and the global SNS index [(VLO + LO)/HI] to plasma leptin concentration were markedly reduced in the obese compared to the control group (VLO per leptin: 5.9 1.39 vs. 37.8 8.1 ms2 ml ng,1, P < 0.01; SNS index per leptin: 0.04 0.008 vs. 0.33 0.01 ml,,,ng,1, P < 0.01). Additionally, a nonlinear regression analysis revealed that these ratios exponentially decreased as a function of body fat content (VLO per leptin r2 = 0.57, P < 0.01; SNS index per leptin r2 = 0.53, P < 0.01). Our data suggest that reduced sympathetic responsiveness to endogenous leptin production, implying peripheral leptin resistance, might be a pathophysiological feature of obesity in otherwise healthy young women. The findings regarding the association of leptin, body fat content, and SNS activity further indicate that the 30% of total body fat, which has been used as a criterion of obesity, might be a critical point at which leptin resistance is induced. Am. J. Hum. Biol. 15:8,15, 2003. 2002 Wiley-Liss, Inc. [source]

Body fat related to daily physical activity and insulin concentrations in non-diabetic children

Magnus Dencker
Summary This study explored the associations between body fat versus daily physical activity and insulin concentrations in non-diabetic young children in a cross-sectional study of 172 children (93 boys and 79 girls) aged 8,11 years. Blood samples were analysed for serum insulin and daily physical activity was measured by accelerometers. Time spent performing vigorous activity was estimated from accelerometer data by using established cut-off points. Dual-energy x-ray absorptiometry (DXA) was used to quantify abdominal fat mass (AFM) and total body fat (TBF), also calculated as percentage of body weight (BF%). Body fat distribution was calculated as AFM/TBF. Body fat distribution was independently linked to both insulin concentrations and physical activity. In contrast, TBF, AFM, and BF% were linked to physical activity only and not to insulin concentrations. In conclusion in this population of non-diabetic children, body fat distribution was independently associated with increased concentrations of insulin and deceased amount of vigorous activity per day. Also, AFM, TBF, and BF% were independently related to minutes of vigorous activity per day. [source]