Physical activity attenuates the body mass index-increasing influence of genetic variation in the FTO gene 1-3.

BACKGROUND: Intronic variation in the FTO (fat mass and obesity-associated) gene has been unequivocally associated with increased body mass index (BMI; in kg/m(2)) and the risk of obesity in populations of different ethnicity. OBJECTIVE: We examined whether this robust genetic predisposition to obesity can be attenuated by being more physically active. DESIGN: The FTO variant rs1121980 was genotyped in 20,374 participants (39-79 y of age) from the European Prospective Investigation into Cancer and Nutrition-Norfolk Study, an ethnically homogeneous population-based cohort. Physical activity (PA) was assessed with a validated self-reported questionnaire. The interaction between rs1121980 and PA on BMI and waist circumference (WC) was examined by including the interaction term in mixed-effect models. RESULTS: We confirmed that the risk (T) allele of rs1121980 was significantly associated with BMI (0.31-unit increase per allele; P < 0.001) and WC (0.77-cm increase per allele; P < 0.001). The PA level attenuated the effect of rs1121980 on BMI and WC; ie, whereas in active individuals the risk allele increased BMI by 0.25 per allele, the increase in BMI was significantly (P for interaction = 0.004) more pronounced (76%) in inactive individuals (0.44 per risk allele). We observed similar effects for WC (P for interaction = 0.02): the risk allele increased WC by 1.04 cm per allele in inactive individuals but by only 0.64 cm in active individuals. CONCLUSIONS: Our results showed that PA attenuates the effect of the FTO rs1121980 genotype on BMI and WC. This observation has important public health implications because we showed that a genetic susceptibility to obesity induced by FTO variation can be overcome, at least in part, by adopting a physically active lifestyle.

Influence of body composition on bone mass in postmenopausal osteoporotic women

We aimed at evaluating the relationship of lean and fat mass to bone mass in osteoporotic postmenopausal women. We invited 65 women who were being treated at the Sao Paulo Hospital osteoporosis outpatients` clinic to participate. Body composition and bone mineral density (BMD) measurements were performed using Dual-energy X-ray absorptiometry methodology (DXA). The mean age and weight were 69.7 +/- 6.4 years and 56.3 +/- 7.6 kg, respectively. Accordingly to the body mass index (BMI), 52.8% were of normal weight and 47.1% of the patients were overweight. Overweight women had significantly higher bone mass. Similarly, skeletal muscle index (SMI) showed a positive effect on BMD measurements and women with sarcopenia had significantly lower BMD measurements in total femur and femoral neck. In multiple regression analysis only lean mass and age, after adjustments to fat mass and BMI, were able to predict total body bone mineral content (BMC) (R(2) = 28%). Also lean mass adjusted to age and BMI were able to predict femoral neck BMD (R(2) = 14%). On the other hand, none of the components of the body composition (lean mass or fat mass) contributed significantly to explaining total femur BMD and neither body composition measurements were associated with spine BMD. These findings suggest that lean mass has a relevant role in BMC and BMD measurements. In addition, lower BMI and lean mass loss (sarcopenia) is associated to lower BMC and BMD of femoral neck and total femur and possible higher risk of osteoporotic fracture. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Influence of protein intake and muscle mass on survival in chronic dialysis patients

Introduction: Some studies suggest that high body mass index (BMI) confers survival advantage in dialysis patients, but BMI does not differentiate muscle from fat mass, and the survival advantage conferred by its increase seems to be limited to patients with high muscle mass. Thus, discriminating body components when evaluating nutritional status and survival is highly important. This study evaluated the influence of nutritional parameters on survival in patients on chronic dialysis. Subjects and methods: Anthropometry, bioimpedance, biochemistry, and dietary recall were used to investigate the influence of nutritional parameters on survival in 79 prevalent patients on chronic dialysis. Results: Protein intake <1.2 g/kg/day and creatinine <9.7 mg/dL were independent predictors of mortality in all patients. Regarding dialysis method, protein intake <1.2 g/kg/ day was predictive of mortality among hemodialysis patients, and percent standard mid-arm muscle circumference <80% was identified as a risk factor among peritoneal dialysis patients. Conclusion: Higher muscle mass, possibly favored by a higher protein intake, conferred survival advantage in dialysis patients.

Association between anthropometric indicators of body fat and metabolic risk markers in post-menopausal women

Objective. to evaluate anthropometric indicators of body fat and their association with metabolic risk markers in postmenopausal women.Methods. A cross-sectional study with 80 Brazilian women (40-70 years) was carried out. Body mass index (BMI = weight/height(2)), waist circumference (WC) and waist-to-hip ratio (WHR) were obtained for anthropometric evaluation. Trunk fat mass (TFM) was measured by dual-energy X-ray absorptiometry. The following metabolic variables were evaluated: total cholesterol (TC), HDL, LDL, triglycerides (TG), as well as glycemia and insulin to determine insulin resistance (HOMA-IR).Results. Overweight and obesity were observed in 81% of the women. Values of WC >88 cm were observed in 68.5% of the women. on average, TC, LDL and TG levels were above normal levels in 60, 50 and 42.5% of the women, respectively; and HDL was normal in 82.5%. IR was observed in 37.5% of the women. Positive correlations were found between anthropometric indicators and TFM (P < 0.05). WC was most correlated with TFM (r = 0.92), followed by BMI (r = 0.88) and by WHR (r = 0.48; P < 0.05). All anthropometric indicators and TFM showed significant negative correlations with HDL and significant positive correlations with HOMA-IR (P < 0.05). Only WHR was significantly associated with dysglycemia (R(2) = 12%), hypertriglyceridemia (R(2) = 17%) and decreased HDL (R(2) = 27%). WC was significantly associated with HOMA-IR (R(2) = 34%).Conclusion. WC and WHR are anthropometric measures that showed strong correlation with TFM and with metabolic risk markers in postmenopausal women.

Plasma hormones, muscle mass and strength in resistance-trained postmenopausal women

Objective: To associate changes of body composition, muscle strength (MS) and plasma hormones (PH) in resistance-training protocol in sedentary postmenopausal women (PMW).Design: This randomized controlled trial, Brazilian 43 PMW (45-70-year-old) able for physical exercises were selected after they have accomplished medical and ethical criteria. They were assigned in two groups: RT, resistance training (n = 22); and CT, not trained control (n = 2 1); with supervision sessions of two to three exercise for large and one exercise for smaller groups in three series of 8-12 rep. (60-80% 1RM) for each exercise. The training period lasted 16 weeks and was preceded by low-load exercise (40-50% 1RM) adaptation period of 4 weeks (3/(times week)). Body weight, height, body mass index (BMI), and composition (BIA) along with fast-PH (FSH, LH, estrachol, cortisol, IGF-1 and testosterone) were assessed before (MO) and after (M 16) the 4 weeks period with the MS (1RM) determined also at 8 weeks (W). The values were correlated by Person's test and the means compared by Student's t-test and ANOVA.Results: At baseline both groups were similar in age, time of PMW, body composition, MS and fast-PH. However after 16 weeks, RT presented higher BMI (2. 1 %), IGF- 1 (37.8%) and MM gain (1.8 +/- 0.8 kg) than CT. MM correlated positively with IGF-1 (r = 0.45, p < 0.05) and MS progressively increased in all exercise greater in pectoral than legs and upper arms.Conclusion: Former sedentary postmenopausal women submitted to resistance training gained MM and MS irrespectively of fat mass changes but significantly associated with IGF-1 increase. (C) 2008 Elsevier B.V. All rights reserved.

Does excess weight interfere with bone mass accumulation during adolescence?

Obesity and osteoporosis are important global health problems characterized by increasing prevalence with high impact on morbidity and mortality. The objective of this review was to determine whether excess weight during adolescence interferes with bone mass accumulation. If bone mineral gain can be optimized during puberty, adults are less likely to suffer from the devastating complications of osteoporosis. The increased fracture risk in obese children has also been attributed to a lower bone mass for weight compared to non-obese children. Thus, adiposity present in this age group may not result in the protection of bone mass, in contrast to what has been observed in adults. However, studies involving adolescents have reported both protective and detrimental effects of obesity on bone. The results and mechanisms of these interactions are controversial and have not been fully elucidated, a fact highlighting the extreme relevance of this topic and the need to monitor intervening and interactive variables. © 2013 by the authors; licensee MDPI, Basel, Switzerland.

Ultrasonographic measurements of kidney fat thickness and Longissimus muscle area in predicting body composition of pregnant goats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Combined training (aerobic plus strength) potentiates a reduction in body fat but demonstrates no difference on the lipid profile in postmenopausal women when compared to aerobic training with a similar training load

The aim of this study was to verify the effects of aerobic and combined training on the body composition and lipid profile of obese postmenopausal women and to analyze which of these models is more effective after equalizing the training load. Sixty five postmenopausal women (age=61.0±6.3 years) were divided into three groups: Aerobic Training (AT,n= 15), Combined Training (CT,[strength+aerobic],n=32) and control group (CG,n=18). Their body composition: upper body fat (TF), fat mass (FM), percentage of fat mass and fat free mass (FFM) were estimated by DXA. The lipid profile, total cholesterol, HDL-cholesterol and LDL-cholesterol were assessed. There was a statistically significant difference in the TF (AT= -4.4 %, CT= -4.4%, and CG= 1.0%, p= 0.001) and FFM (AT= 1.7%, CT= 2.6%, and CG= -1.4%, p= 0.0001) between the experimental and the control groups. Regarding the percentage of body fat, there was a statistically significant difference only between the CT and CG groups (AT= -2.8%, CT= -3.9% and CG= 0.31%, p= 0.004). When training loads were equalized, the aerobic and combined training decreased core fat and increased fat-free mass, but only the combined training potentiated a reduction in percentage of body fat in obese postmenopausal women after the training program. HDL-c levels increased in the combined group and the chol/HDL ratio (atherogenic index) decreased in the aerobic group, however, there were no significant differences between the intervention programs. Taken together, both the exercise training programs were effective for improving body composition and inducing an anti-atherogenic status.

Estimating total body fat using a skinfold prediction equation in Brazilian children

Background: The double burden of obesity and underweight is increasing in developing countries and simple methods for the assessment of fat mass in children are needed. Aim: To develop and validate a new anthropometric predication equation for assessment of fat mass in children. Subjects and methods: Body composition was assessed in 145 children aged 9.8 +/- 1.3 (SD) years from Sao Paulo, Brazil using dual energy X-ray absorptiometry (DEXA) and skinfold measurements. The study sample was divided into development and validation sub-sets to develop a new prediction equation for FM (PE). Results: Using multiple linear regression analyses, the best equation for predicting FM (R-2 - 0.77) included body weight, triceps skinfold, height, gender and age as independent variables. When cross-validated, the new PE was valid in this sample (R-2 = 0.80), while previously published equations were not. Conclusion: The PE was more valid for Brazilian children that existing equations, but further studies are needed to assess the validity of this PE in other populations.

Elevated tissue omega-3 fatty acid status prevents age-related glucose intolerance in fat-1 transgenic mice

The objective of this study was to investigate the impact of elevated tissue omega-3 (n-3) polyunsaturated fatty acids (PUFA) status on age-related glucose intolerance utilizing the fat-1 transgenic mouse model, which can endogenously synthesize n-3 PUFA from omega-6 (n-6) PUFA. Fat-1 and wild-type mice, maintained on the same dietary regime of a 10% corn oil diet, were tested at two different ages (2months old and 8months old) for various glucose homeostasis parameters and related gene expression. The older wild-type mice exhibited significantly increased levels of blood insulin, fasting blood glucose, liver triglycerides, and glucose intolerance, compared to the younger mice, indicating an age-related impairment of glucose homeostasis. In contrast, these age-related changes in glucose metabolism were largely prevented in the older fat-1 mice. Compared to the older wild-type mice, the older fat-1 mice also displayed a lower capacity for gluconeogenesis, as measured by pyruvate tolerance testing (PTT) and hepatic gene expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6 phosphatase (G6Pase). Furthermore, the older fat-1 mice showed a significant decrease in body weight, epididymal fat mass, inflammatory activity (NFκ-B and p-IκB expression), and hepatic lipogenesis (acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) expression), as well as increased peroxisomal activity (70-kDa peroxisomal membrane protein (PMP70) and acyl-CoA oxidase1 (ACOX1) expression). Altogether, the older fat-1 mice exhibit improved glucose homeostasis in comparison to the older wild-type mice. These findings support the beneficial effects of elevated tissue n-3 fatty acid status in the prevention and treatment of age-related chronic metabolic diseases

Muscular development and physical activity as major determinants of femoral bone mass acquisition during growth

[EN] OBJECTIVES: To investigate to what extent bone mass accrual is determined by physical activity and changes in lean, fat, and total body mass during growth. METHODS: Twenty six physically active and 16 age matched control boys were followed up for three years. All subjects were prepubertal at the start of the survey (mean (SEM) age 9.4 (0.3) years). The weekly physical activity of the active boys included compulsory physical education sessions (80-90 minutes a week), three hours a week of extracurricular sports participation, and occasional sports competitions at weekends. The physical activity of the control group was limited to the compulsory physical education curriculum. Bone mineral content (BMC) and areal density (BMD), lean mass, and fat mass were measured by dual energy x ray absorptiometry. RESULTS: The effect of sports participation on femoral bone mass accrual was remarkable. Femoral BMC and BMD increased twice as much in the active group as in the controls over the three year period (p < 0.05). The greatest correlation was found between the increment in femoral bone mass and the increment in lean mass (BMC r = 0.67 and BMD r = 0.69, both p < 0.001). Multiple regression analysis revealed enhancement in lean mass as the best predictor of the increment in femoral bone BMC (R = 0.65) and BMD (R = 0.69). CONCLUSIONS: Long term sports participation during early adolescence results in greater accrual of bone mass. Enhancement of lean mass seems to be the best predictor of this bone mass accumulation. However, for a given muscle mass, a greater level of physical activity is associated with greater bone mass and density in peripubertal boys.

Strength training combined with plyometric jumps in adults: sex differences in fat-bone axis adaptations

[EN] Leptin and osteocalcin play a role in the regulation of the fat-bone axis and may be altered by exercise. To determine whether osteocalcin reduces fat mass in humans fed ad libitum and if there is a sex dimorphism in the serum osteocalcin and leptin responses to strength training, we studied 43 male (age 23.9 2.4 yr, mean +/- SD) and 23 female physical education students (age 23.2 +/- 2.7 yr). Subjects were randomly assigned to two groups: training (TG) and control (CG). TG followed a strength combined with plyometric jumps training program during 9 wk, whereas the CG did not train. Physical fitness, body composition (dual-energy X-ray absorptiometry), and serum concentrations of hormones were determined pre- and posttraining. In the whole group of subjects (pretraining), the serum concentration of osteocalcin was positively correlated (r = 0.29-0.42, P < 0.05) with whole body and regional bone mineral content, lean mass, dynamic strength, and serum-free testosterone concentration (r = 0.32). However, osteocalcin was negatively correlated with leptin concentration (r = -0.37), fat mass (r = -0.31), and the percent body fat (r = -0.44). Both sexes experienced similar relative improvements in performance, lean mass (+4-5%), and whole body (+0.78%) and lumbar spine bone mineral content (+1.2-2%) with training. Serum osteocalcin concentration was increased after training by 45 and 27% in men and women, respectively (P < 0.05). Fat mass was not altered by training. Vastus lateralis type II MHC composition at the start of the training program predicted 25% of the osteocalcin increase after training. Serum leptin concentration was reduced with training in women. In summary, while the relative effects of strength training plus plyometric jumps in performance, muscle hypertrophy, and osteogenesis are similar in men and women, serum leptin concentration is reduced only in women. The osteocalcin response to strength training is, in part, modulated by the muscle phenotype (MHC isoform composition). Despite the increase in osteocalcin, fat mass was not reduced.

The effect of GH replacement therapy on different fat compartments: a whole-body magnetic resonance imaging study

Patients with GH deficiency (GHD) are insulin resistant with an increase in visceral fat mass (FM). Whether this holds true when sedentary control subjects (CS) are matched for waist has not been documented. GH replacement therapy (GHRT) results in a decrease in FM. Whether the decrease in FM is mainly related to a reduction in visceral FM remains to be proven. The aim was to separately assess visceral and subcutaneous FM in relation to insulin resistance (IR) in GHD patients before and after GHRT and in sedentary CS.

The importance of growth hormone in the regulation of erythropoiesis, red cell mass, and plasma volume in adults with growth hormone deficiency

Total body water (TBW) is reduced in adult GH deficiency (GHD) largely due to a reduction of extracellular water. It is unknown whether total blood volume (TBV) contributes to the reduced extracellular water in GHD. GH and insulin-like growth factor I (IGF-I) have been demonstrated to stimulate erythropoiesis in vitro, in animal models, and in growing children. Whether GH has a regulatory effect on red cell mass (RCM) in adults is not known. We analyzed body composition by bioelectrical impedance and used standard radionuclide dilution methods to measure RCM and plasma volume (PV) along with measuring full blood count, ferritin, vitamin B12, red cell folate, IGF-I, IGF-binding protein-3, and erythropoietin in 13 adult patients with GHD as part of a 3-month, double blind, placebo-controlled trial of GH (0.036 U/kg.day). TBW and lean body mass significantly increased by 2.5 +/- 0.53 kg (mean +/- SEM; P < 0.004) and 3.4 +/- 0.73 kg (P < 0.004), respectively, and fat mass significantly decreased by 2.4 +/- 0.32 kg (P < 0.001) in the GH-treated group. The baseline RCM of all patients with GHD was lower than the predicted normal values (1635 +/- 108 vs. 1850 +/- 104 mL; P < 0.002). GH significantly increased RCM, PV, and TBV by 183 +/- 43 (P < 0.006), 350 +/- 117 (P < 0.03), and 515 +/- 109 (P < 0.004) mL, respectively. The red cell count increased by 0.36 +/- 0.116 x 10(12)/L (P < 0.03) with a decrease in ferritin levels by 39.1 +/- 4.84 micrograms/L (P < 0.001) after GH treatment. Serum IGF-I and IGF-binding protein-3 concentrations increased by 3.0 +/- 0.43 (P < 0.001) and 1.3 +/- 0.15 (P < 0.001) SD, respectively, but the erythropoietin concentration was unchanged after GH treatment. No significant changes in body composition or blood volume were recorded in the placebo group. Significant positive correlations could be established between changes in TBW and TBV, lean body mass and TBV (r = 0.78; P < 0.04 and r = 0.77; P < 0.04, respectively), and a significant negative correlation existed between changes in fat mass and changes in TBV in the GH-treated group (r = -0.95; P < 0.02). We conclude that 1) erythropoiesis is impaired in GHD; 2) GH stimulates erythropoiesis in adult GHD; and 3) GH increases PV and TBV, which may contribute to the increased exercise performance seen in these patients.

Effects of deflazacort versus prednisone on bone mass, body composition, and lipid profile: a randomized, double blind study in kidney transplant patients

To compare the effects of deflazacort (DEFLA) vs. prednisone (PRED) on bone mineral density (BMD), body composition, and lipids, 24 patients with end-stage renal disease were randomized in a double blind design and followed 78 weeks after kidney transplantation. BMD and body composition were assessed using dual energy x-ray absorptiometry. Seventeen patients completed the study. Glucocorticosteroid doses, cyclosporine levels, rejection episodes, and drop-out rates were similar in both groups. Lumbar BMD decreased more in PRED than in DEFLA (P < 0.05), the difference being particularly marked after 24 weeks (9.1 +/- 1.8% vs. 3.0 +/- 2.4%, respectively). Hip BMD decreased from baseline in both groups (P < 0.01), without intergroup differences. Whole body BMD decreased from baseline in PRED (P < 0.001), but not in DEFLA. Lean body mass decreased by approximately 2.5 kg in both groups after 6-12 weeks (P < 0.001), then remained stable. Fat mass increased more (P < 0.01) in PRED than in DEFLA (7.1 +/- 1.8 vs. 3.5 +/- 1.4 kg). Larger increases in total cholesterol (P < 0.03), low density lipoprotein cholesterol (P < 0.01), lipoprotein B2 (P < 0.03), and triglycerides (P = 0.054) were observed in PRED than in DEFLA. In conclusion, using DEFLA instead of PRED in kidney transplant patients is associated with decreased loss of total skeleton and lumbar spine BMD, but does not alter bone loss at the upper femur. DEFLA also helps to prevent fat accumulation and worsening of the lipid profile.