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Fat Mass (fat + mass)
Kinds of Fat Mass Selected AbstractsHormone Replacement Therapy Dissociates Fat Mass and Bone Mass, and Tends to Reduce Weight Gain in Early Postmenopausal Women: A Randomized Controlled 5-Year Clinical Trial of the Danish Osteoporosis Prevention Study,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2003LB Jensen MD Abstract The aim of this study was to study the influence of hormone replacement therapy (HRT) on weight changes, body composition, and bone mass in early postmenopausal women in a partly randomized comprehensive cohort study design. A total of 2016 women ages 45,58 years from 3 months to 2 years past last menstrual bleeding were included. One thousand were randomly assigned to HRT or no HRT in an open trial, whereas the others were allocated according to their preferences. All were followed for 5 years for body weight, bone mass, and body composition measurements. Body weight increased less over the 5 years in women randomized to HRT (1.94 ± 4.86 kg) than in women randomized to no HRT (2.57 ± 4.63, p = 0.046). A similar pattern was seen in the group receiving HRT or not by their own choice. The smaller weight gain in women on HRT was almost entirely caused by a lesser gain in fat. The main determinant of the weight gain was a decline in physical fitness. Women opting for HRT had a significantly lower body weight at inclusion than the other participants, but the results in the self-selected part of the study followed the pattern found in the randomized part. The change in fat mass was the strongest predictor of bone changes in untreated women, whereas the change in lean body mass was the strongest predictor when HRT was given. Body weight increases after the menopause. The gain in weight is related to a decrease in working capacity. HRT is associated with a smaller increase in fat mass after menopause. Fat gain protects against bone loss in untreated women but not in HRT-treated women. The data suggest that women's attitudes to HRT are more positive if they have low body weight, but there is no evidence that the conclusions in this study are skewed by selection bias. [source] Differential Effects of Restricted Versus Unlimited High-Fat Feeding in Rats on Fat Mass, Plasma Hormones and Brain Appetite RegulatorsJOURNAL OF NEUROENDOCRINOLOGY, Issue 7 2009T. Shiraev The rapid rise in obesity has been linked to altered food consumption patterns. There is increasing evidence that, in addition to total energy intake, the macronutrient composition of the diet may influence the development of obesity. The present study aimed to examine the impact of high dietary fat content, under both isocaloric and hypercaloric conditions, compared with a low fat diet, on adiposity, glucose and lipid metabolism, and brain appetite regulators in rats. Male Sprague,Dawley rats were exposed to one of three diets: control (14% fat), ad lib high-fat palatable (HFD, 35% fat) or high-fat palatable restricted (HFD-R, matched to the energy intake of control) and were killed in the fasting state 11 weeks later. Body weight was increased by 28% in unrestricted HFD fed rats, with an almost tripling of caloric intake and fat mass (P < 0.001) and double the plasma triglycerides of controls. Glucose intolerance and increased insulin levels were observed. HFD-R animals calorie matched to control had double their fat mass, plasma insulin and triglycerides (P < 0.05). Only ad lib consumption of the HFD increased the hypothalamic mRNA expression of the appetite-regulating peptides, neuropeptide Y and pro-opiomelanocortin. Although restricted consumption of palatable HFD had no significant impact on hypothalamic appetite regulators or body weight, it increased adiposity and circulating triglycerides, suggesting that the proportion of dietary fat, independent of caloric intake, affects fat deposition and the metabolic profile. [source] Obesity and metabolic changes are common in young childhood brain tumor survivorsPEDIATRIC BLOOD & CANCER, Issue 7 2009Sari Pietilä MD Abstract Background A population based cross-sectional study was used to examine the prevalence of metabolic syndrome and its components in childhood brain tumor survivors. Procedure Fifty-two survivors were examined at a mean age of 14.4 years (range 3.8,28.7). Lipid and glucose metabolism, thyroid function, and plasma uric acid were evaluated. Fat mass and fat percentage were assessed by dual-energy X-ray absorptiometry (DXA). Metabolic syndrome was defined on International Diabetes Federation criteria. Results Ten (19%) patients were overweight and four (8%) were obese. According to DXA, 16/46 (35%) patients were obese. Central obesity was found in 11 (21%) patients. Cranial irradiation, hypothalamic/hypophyseal damage, growth hormone (GH) deficiency and impaired mobility were associated with overweight/obesity and central obesity. Thirteen (25%) subjects had hypercholesterolemia, 14 (27%) had raised low-density lipoprotein cholesterol (LDL-C), 12 (23%) had raised blood pressure, four (8%) had metabolic syndrome, two (4%) had hyperinsulinemia and five (10%) had hyperuricemia. Cranial irradiation was associated with hypercholesterolemia (P,=,0.019), raised LDL-C (P,=,0.028), raised blood pressure (P,=,0.040), and metabolic syndrome (P,=,0.018). Impaired mobility was associated with hypercholesterolemia (P,=,0.034). Hypothalamic/hypophyseal damage was associated with metabolic syndrome (P,=,0.003) and hyperuricemia (P,=,0.011) as was GH deficiency (P,=,0.034 and P,=,0.008). GH supplementation alleviated adverse metabolic outcomes among brain tumor survivors with GH deficiency. Conclusions Obesity/overweight, dyslipidemia, hypertension, metabolic syndrome, and hyperuricemia were common in young childhood brain tumor survivors. Cranial irradiation, hypothalamic/hypophyseal damage, growth hormone deficiency, and/or impaired mobility were associated with higher risk for obesity and metabolic changes among these patients. Pediatr Blood Cancer 2009;52:853,859. © 2009 Wiley-Liss, Inc. [source] Glucose tolerance status in 510 children and adolescents attending an obesity clinic in Central ItalyPEDIATRIC DIABETES, Issue 1 2010Claudia Brufani Brufani C, Ciampalini P, Grossi A, Fiori R, Fintini D, Tozzi A, Cappa M, Barbetti F. Glucose tolerance status in 510 children and adolescents attending an obesity clinic in Central Italy. Childhood obesity is epidemic in developed countries and is accompanied by an increase in the prevalence of type 2 diabetes (T2DM). Aims: Establish prevalence of glucose metabolism alterations in a large sample of overweight/obese children and adolescents from Central Italy. Methods: The study group included 510 overweight/obese subjects (3,18 yr). Oral glucose tolerance test (OGTT) was performed with glucose and insulin determination. Homeostatic model assessment of insulin resistance (HOMA-IR) and insulin sensitivity index (ISI) were derived from fasting and OGTT measurements. Beta-cell function was estimated by insulinogenic index. Fat mass was measured by dual-energy x-ray absorptiometry. Results: Glucose metabolism alterations were detected in 12.4% of patients. Impaired glucose tolerance (IGT) was the most frequent alteration (11.2%), with a higher prevalence in adolescents than in children (14.8 vs. 4.1%, p < 0.001); silent T2DM was identified in two adolescents (0.4%). HOMA-IR and glucose-stimulated insulin levels were higher in patients with IGT than individuals with normal glucose tolerance (HOMA-IR = 4.4 ± 2.5 vs. 3.4 ± 2.3, p = 0.001). Fat mass percentage and insulinogenic index were not different between the two groups. In multivariate analysis, age, fasting glucose, and insulin resistance influenced independently plasma glucose at 120 min of OGTT. Individuals with combined impaired fasting glucose/IGT (IFG/IGT) and T2DM were older and had reduced plasma insulin values at OGTT when compared to patients with simple IGT. Conclusions: Glucose metabolism alterations are frequently found among children and adolescents with overweight/obesity from Central Italy. Age, fasting glucose, and insulin resistance are main predictors of IGT. We suggest the use of OGTT as a screening tool in obese European adolescents. [source] Body composition and respiratory function in healthy non-obese childrenPEDIATRICS INTERNATIONAL, Issue 5 2007FRANCISCO J. GONZALEZ-BARCALA Abstract Background: The purpose of the present paper was to evaluate the role that body composition plays in lung function, among healthy children and adolescents. Methods: Cross-sectional study was undertaken using sex- and age-stratified sampling among healthy children and adolescents aged 6,18 years. Spirometry was performed on every child who fulfilled inclusion criteria. Fat mass (FM) and fat-free mass (FFM) were calculated from triceps skinfold thickness and arm circumference. Multiple logistic regression was used to obtain adjusted prevalence odds ratios (OR) and 95% confidence intervals (95%CI) between low pulmonary function (PF) of schoolchildren and body composition expressed in FM and FFM. Calculations of OR imply that the outcome is dichotomous (low PF/normal PF), therefore those children who had parameters of pulmonary function below the 25th percentile were classed as cases and the rest of the subjects were considered as controls. Results: A total of 2408 children were included; 1270 (53%) of them were male and 1138 (47%), female. Among boys the increase of FFM was associated with an increase of forced expiratory volume in 1 s (FEV1). Among girls the increase of FFM was associated with an increase of FEV1, forced vital capacity, and peak expiratory flow. The increase in FM was associated with a decrease of spirometric parameters in both genders, with a stronger effect among boys. Conclusions: The present study confirms the negative effect of body fat on the PF of children and adolescents, even though obese subjects were excluded. The effect is different between boys and girls. [source] Impact of carbohydrate supplementation during endurance training on glycogen storage and performanceACTA PHYSIOLOGICA, Issue 2 2009L. Nybo Abstract Aim:, Glucose ingestion may improve exercise endurance, but it apparently also influences the transcription rate of several metabolic genes and it alters muscle metabolism during an acute exercise bout. Therefore, we investigated how chronic training responses are affected by glucose ingestion. Methods:, In previously untrained males performance and various muscular adaptations were evaluated before and after 8 weeks of supervised endurance training conducted either with (n = 8; CHO group) or without (n = 7; placebo) glucose supplementation. Results:, The two groups achieved similar improvements in maximal oxygen uptake and peak power output during incremental cycling (both parameters elevated by 17% on average) and both groups lost ,3 kg of fat mass during the 8 weeks of training. An equal reduction in respiratory exchange ratio (0.02 units) during submaximal exercise was observed in both groups. Beta-hydroxyacyl-CoA-dehydrogenase activity was increased in both groups, however, to a larger extent in the placebo group (45 ± 11%) than CHO (23 ± 9%, P < 0.05). GLUT-4 protein expression increased by 74 ± 14% in the placebo group and 45 ± 14% in CHO (both P < 0.05), while resting muscle glycogen increased (P < 0.05) to a larger extent in the placebo group (96 ± 4%) than CHO (33 ± 2%). Conclusion:, These results show that carbohydrate supplementation consumed during exercise training influences various muscular training adaptations, but improvements in cardiorespiratory fitness and reductions in fat mass are not affected. [source] Increased fat oxidation and regulation of metabolic genes with ultraendurance exerciseACTA PHYSIOLOGICA, Issue 1 2007J. W. Helge Abstract Aim:, Regular endurance exercise stimulates muscle metabolic capacity, but effects of very prolonged endurance exercise are largely unknown. This study examined muscle substrate availability and utilization during prolonged endurance exercise, and associated metabolic genes. Methods:, Data were obtained from 11 competitors of a 4- to 5-day, almost continuous ultraendurance race (seven males, four females; age: 36 ± 11 years; cycling o2peak: males 57.4 ± 5.9, females 48.1 ± 4.0 mL kg,1 min,1). Before and after the race muscle biopsies were obtained from vastus lateralis, respiratory gases were sampled during cycling at 25 and 50% peak aerobic power output, venous samples were obtained, and fat mass was estimated by bioimpedance under standardized conditions. Results:, After the race fat mass was decreased by 1.6 ± 0.4 kg (11%; P < 0.01). Respiratory exchange ratio at the 25 and 50% workloads decreased (P < 0.01) from 0.83 ± 0.06 and 0.93 ± 0.03 before, to 0.71 ± 0.01 and 0.85 ± 0.02, respectively, after the race. Plasma fatty acids were 3.5 times higher (from 298 ± 74 to 1407 ± 118 ,mol L,1; P < 0.01). Muscle glycogen content fell 50% (from 554 ± 28 to 270 ± 25 nmol kg,1 d.w.; n = 7, P < 0.01), whereas the decline in muscle triacylglycerol (from 32 ± 5 to 22 ± 3 mmol kg,1 d.w.; P = 0.14) was not statistically significant. After the race, muscle mRNA content of lipoprotein lipase and glycogen synthase increased (P < 0.05) 3.9- and 1.7-fold, respectively, while forkhead homolog in rhabdomyosarcoma, pyruvate dehydrogenase kinase 4 and vascular endothelial growth factor mRNA tended (P < 0.10) to be higher, whereas muscle peroxisome proliferator-activated receptor , co-activator-1, mRNA tended to be lower (P = 0.06). Conclusion:, Very prolonged exercise markedly increases plasma fatty acid availability and fat utilization during exercise. Exercise-induced regulation of genes encoding proteins involved in fatty acid recruitment and oxidation may contribute to these changes. [source] Rosiglitazone is more effective than metformin in improving fasting indexes of glucose metabolism in severely obese, non-diabetic patientsDIABETES OBESITY & METABOLISM, Issue 6 2008A. Brunani Aim:, In obese patients, the diet-induced weight loss markedly improves glucose tolerance with an increase in insulin sensitivity and a partial reduction of insulin secretion. The association with metformin treatment might potentiate the effect of diet alone. Methods:, From patients admitted to our Nutritional Division for diet programme, we selected obese, non-diabetic, uncomplicated patients with age 18,65 years and body mass index 35,50 kg/m2 and studied the effects of a 6-month pharmacological treatment with either metformin (850 mg twice daily) or rosiglitazone (4 mg twice daily) on possible changes in body weight, fat mass, glucose and lipids metabolism. Results:, A significant weight loss and reduction of fat mass was demonstrated with metformin (,9.7 ± 1.8 kg and ,6.6 ± 1.1 kg) and also with rosiglitazone (,11.0 ± 1.9 kg and ,7.2 ± 1.8 kg), without fluid retention in either treatment group. Rosiglitazone administration induced a significant decrease in glucose concentration (4.7 ± 0.1 vs. 4.4 ± 0.1 mmol/l, p < 0.005) and insulin-circulating level (13.6 ± 1.5 vs. 8.0 ± 0.,7 ,U/ml, p < 0.005), an increase in insulin sensitivity as measured by homeostatic model assessment (HOMA) of insulin sensitivity (68.9 ± 8.8 vs. 109.9 ± 10.3, p < 0.005) with a concomitant decrease in ,-cell function as measured by HOMA of ,-cell function (163.2 ± 16.1 vs. 127.4 ± 8.4, p < 0.005). In contrast, metformin did not produce any significant effect on blood glucose concentration, insulin level and HOMA2 indexes. No adverse events were registered with pharmacological treatments. Conclusion:, Our study shows that in severely obese, non-diabetic, hyperinsulinaemic patients undergoing a nutritional programme, rosiglitazone is more effective than metformin in producing favourable changes in fasting-based indexes of glucose metabolism, with a reduction of both insulin resistance and hyperinsulinaemia. In spite of previous studies reporting rosiglitazone-induced body weight gain, in our study the joint treatment with diet and rosiglitazone was accompanied by weight loss and fat mass reduction. [source] Administration of myostatin does not alter fat mass in adult miceDIABETES OBESITY & METABOLISM, Issue 2 2008L. E. Stolz Aim: Myostatin, a member of the TGF-beta superfamily, is produced by skeletal muscle and acts as a negative regulator of muscle mass. It has also been suggested that low-dose administration of myostatin (2 ,g/day) in rodents can reduce fat mass without altering muscle mass. In the current study, we attempted to further explore the effects of myostatin on adipocytes and its potential to reduce fat mass, since myostatin administration could potentially be a useful strategy to treat obesity and its complications in humans. Methods: Purified myostatin protein was examined for its effects on adipogenesis and lipolysis in differentiated 3T3-L1 adipocytes as well as for effects on fat mass in wild-type, myostatin null and obese mice. Results: While myostatin was capable of inhibiting adipogenesis in 3T3-L1 cells, it did not alter lipolysis in fully differentiated adipocytes. Importantly, pharmacological administration of myostatin over a range of doses (2,120 ,g/day) did not affect fat mass in wild-type or genetically obese (ob/ob, db/db) mice, although muscle mass was significantly reduced at the highest myostatin dose. Conclusions: Our results suggest that myostatin does not reduce adipose stores in adult animals. Contrary to prior indications, pharmacological administration of myostatin does not appear to be an effective strategy to treat obesity in vivo. [source] Subnormal energy expenditure: a putative causal factor in the weight gain induced by treatment of hyperthyroidismDIABETES OBESITY & METABOLISM, Issue 2 2006R. Jacobsen Aims:, To examine the causes of weight gain occurring as an adverse effect of treatment of hyperthyroidism. Methods:, We measured 24-h energy expenditure (EE), body composition and spontaneous physical activity (SPA) in eight patients before and 1 year after treatment of hyperthyroidism was initiated, and eight controls. Results:, One year after initiation of treatment thyrotropin was normalized, thyroid hormones had fallen to the lower end of the reference range and fat mass had increased by 3.5 kg (p < 0.001). Twenty-four hour EE adjusted for fat-free mass (FFM) was 15% higher in hyperthyroid patients before treatment than in controls (p = 0.003), and treatment decreased 24-h EE by 1.9 MJ/day (p = 0.001). After treatment, 24-h EE, adjusted for FFM, was similar to the controls. Multiple regression analyses showed that the suppressed EE could partly be attributed to an iatrogenic suppression of thyroid hormones, resulting in lower sleeping EE. Twenty-four hour SPA was normal in the hyperthyroid state, but decreased after treatment by 21% (p = 0.045), to a level not significantly different, but still below that of the controls. Conclusions:, The study suggests that weight gain during treatment of hyperthyroidism might be due to subnormal levels of EE and SPA caused by a suppression of the thyroid hormone to a level in the lower end of the normal range. [source] Minor long-term changes in weight have beneficial effects on insulin sensitivity and ,-cell function in obese subjectsDIABETES OBESITY & METABOLISM, Issue 1 2002A. M. Rosenfalck SUMMARY Aim To evaluate the long-term effect of changes in body composition induced by weight loss on insulin sensitivity (SI), non-insulin mediated glucose disposal, glucose effectiveness (SG) and ,-cell function. Design Glucose metabolism was evaluated before and after participation in a two-year weight loss trial of Orlistat vs. placebo, combined with an energy and fat restricted diet. Subjects Twelve obese patients (11 women, 1 man), age 45.8 ± 10.5 years, body weight (BW) 99.7 ± 13.3 kg, BMI 35.3 ± 2.8 kg/m2. Measurements At inclusion and 2 years later an oral glucose tolerance test (OGTT) and a frequently sampled intravenous glucose tolerance test (FSIGT) were performed. Body composition was estimated by a dual-energy X-ray absorptiometry (DXA) whole body scanning. Results The patients obtained varying changes in BW ranging from a weight loss of 17.8 kg to a weight gain of 6.0 kg. Corresponding changes in fat mass (FM) varied from a 40% reduction to a 19% increase. A significant decrease in both fasting (p =,0.038) and 2 h (p =,0.047) blood glucose at OGTT was found. The improvement in insulin sensitivity (SI) estimated by means of Bergmans Minimal Model, was significantly and linearly correlated to change in total FM (r = , 0.83, p =,0.0026). A multiple regression analysis showed that changes in truncal FM was the strongest predictor of change in SI explaining 67% of the variation. First phase insulin response (AIRg) remained unchanged whereas insulin disposition index increased significantly (p =,0.044). At inclusion five patients had impaired glucose tolerance of which four, who lost weight, were normalized at the retest 2 years later. Conclusion In obese subjects long-term minimal or moderate changes in weight were found to be linearly associated with changes in insulin sensitivity. In obese subjects with impaired glucose tolerance even a minor weight loss was able to normalize glucose tolerance. [source] Enhanced weight loss with protein-enriched meal replacements in subjects with the metabolic syndromeDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 5 2010Marion Flechtner-Mors Abstract Background The objective of this study was to investigate the effects of a protein-rich diet in comparison with a conventional protein diet on weight loss, weight maintenance, and body composition in subjects with the metabolic syndrome. Methods Obese subjects received instructions for an energy-restricted diet with a calorie deficit of 500 kcal/day and were randomly assigned to either high-protein (1.34 g/kg body weight) or conventional protein (0.8 g/kg body weight) diets for 12 months. Protein-enriched meal replacements were used to enrich one arm of the diet with protein throughout the study. In all, 67% of the participants completed the 1-year study. Results Subjects following the high-protein diet lost more body weight and more fat mass compared with those on the conventional protein diet, whereas the loss of fat-free mass was similar in both diet groups. Biochemical parameters associated with the metabolic syndrome improved in both diet groups. Improvements were modestly greater in subjects with the high-protein diet. After 12 months of treatment, 64.5% of the subjects in the high-protein diet group and 34.8% of the subjects in the conventional diet group no longer met three or more of the criteria for having the metabolic syndrome. Conclusions Individuals with the metabolic syndrome achieved significant weight loss while preserving fat-free mass when treated with an energy-restricted, high-protein diet that included nutrient-dense meal replacements, as compared with the results for conventional protein intake. An intervention with a protein-enriched diet may have advantages for the management of the metabolic syndrome. Copyright © 2010 John Wiley & Sons, Ltd. [source] Diabetes: insulin resistance and derangements in lipid metabolism.DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 1 2005Cure through intervention in fat transport, storage Abstract We present multiple findings on derangements in lipid metabolism in type 2 diabetes. The increase in the intracellular deposition of triglycerides (TG) in muscles, liver and pancreas in subjects prone to diabetes is well documented and demonstrated to attenuate glucose metabolism by interfering with insulin signaling and insulin secretion. The obesity often associated with type 2 diabetes is mainly central, resulting in the overload of abdominal adipocytes with TG and reducing fat depot capacity to protect other tissues from utilizing a large proportion of dietary fat. In contrast to subcutaneous adipocytes, the central adipocytes exhibit a high rate of basal lipolysis and are highly sensitive to fat mobilizing hormones, but respond poorly to lipolysis restraining insulin. The enlarged visceral adipocytes are flooding the portal circulation with free fatty acids (FFA) at metabolically inappropriate time, when FFA should be oxidized, thus exposing nonadipose tissues to fat excess. This leads to ectopic TG accumulation in muscles, liver and pancreatic beta-cells, resulting in insulin resistance and beta-cell dysfunction. This situation, based on a large number of observations in humans and experimental animals, confirms that peripheral adipose tissue is closely regulated, performing a vital role of buffering fluxes of FFA in the circulation. The central adipose tissues tend to upset this balance by releasing large amounts of FFA. To reduce the excessive fat outflow from the abdominal depots and prevent the ectopic fat deposition it is important to decrease the volume of central fat stores or increase the peripheral fat stores. One possibility is to downregulate the activity of lipoprotein lipase, which is overexpressed in abdominal relatively to subcutaneous fat stores. This can be achieved by gastrointestinal bypass or gastroplasty, which decrease dietary fat absorption, or by direct means that include surgical removal of mesenteric fat. Indirect treatment consists of the compliant application of drastic lifestyle change comprising both diet and exercise and pharmacotherapy that reduces mesenteric fat mass and activity. The first step should be an attempt to effectively induce a lifestyle change. Next comes pharmacotherapy including acarbose, metformin, PPAR,, or PPAR,, agonists, statins and orlistat, estrogens in postmenopausal women or testosterone in men. Among surgical procedures, gastric bypass has been proven to produce beneficial results in advance of other surgical techniques, the evidence basis of which still needs strengthening. Copyright © 2004 John Wiley & Sons, Ltd. [source] Central fat predicts deterioration of insulin secretion index and fasting glycaemia: 6-year follow-up of subjects at varying risk of Type 2 diabetes mellitusDIABETIC MEDICINE, Issue 4 2003A. D. Kriketos Abstract Aims To examine the relationships between body composition and changes in fasting glycaemia, and in indices of insulin secretion and insulin action over 6 years in females with a family history of Type 2 diabetes with or without prior gestational diabetes (,at risk' group, AR) and control females (control group, C). Methods At baseline and at follow-up, an oral glucose tolerance test and dual energy X-ray absorptiometry assessment of body composition were performed. Indices of insulin resistance (HOMA R,) and insulin secretion (HOMA ,,) were obtained from fasting insulin and glucose concentrations. Results At baseline, the groups were similar for age, body mass index, fasting levels of plasma glucose and insulin, HOMA R, and HOMA ,,. Despite similar total body fatness, AR had significantly greater waist circumference and central fat (both P < 0.02) compared with C. At follow-up there was a significant increase in central adiposity only in AR, and the fasting plasma glucose (FPG) level was higher in AR compared with C (5.0 ± 0.2 vs. 4.3 ± 0.2 mmol/l, P = 0.02). This rise in plasma glucose in AR was related to a decline in HOMA ,, (r = 0.45, P = 0.0065). Both the baseline and the increments in total and central abdominal fat mass were associated with the time-related decline in HOMA ,,. Conclusions Six years after initial assessment, AR showed deterioration in FPG levels due predominantly to a decline in insulin secretion index without major change in insulin resistance index. Importantly, baseline body fatness (especially central adiposity), as well as increases in fatness with time, were the major predictors of the subsequent decline of insulin secretion index and the consequent rise in FPG. [source] Body composition in young Standardbreds in training: relationships to body condition score, physiological and locomotor variables during exerciseEQUINE VETERINARY JOURNAL, Issue S36 2006C. LELEU Summary Reasons for performing study: Body composition is an essential factor in athletic performance of human sprinters and long distance runners. However, in horses, many questions remain concerning relationships between body composition and performance in the different equine activities. Objectives: To determine relationships between body composition, body score, physiological and locomotor variables in a population of young Standardbreds in training. Methods: Twenty-four 2-year-old Standardbreds were studied, body condition on a scale 0,5 and bodyweight recorded, and height at withers measured. Percentage of fat (%F), fat mass (FM) and fat free mass (FFM) were estimated echographically. During a standardised exercise test on the track, velocity, heart rate, respiratory frequency and blood lactate concentrations were measured. V4 and V200 (velocity for a blood lactate concentration of 4 mmol/1 and velocity of 200 beats/min) calculated. Basic gait variables were measured at 3 different speeds with an accelerometric device. Results: Body composition variables: %F and FM were significantly related to body condition score and physiological variables. Body score was highly correlated to %F (r=0.64) and FM (r = 0.71). V4 was negatively correlated to %V (r=-0.59) and FM (r = -0.60), P<0.05. V200 was also negatively related to %F and FM, (r=-0.39 and r = -0.37, respectively, P<0.1). No relationships were found between body composition and gait characteristics. Conclusions: Body composition was closely related to indirect measurements of aerobic capacity, which is a major factor of athletic performance in middle distance running horses. Potential relevance: As in human athletes, trainers should take special note to evaluate optimal bodyweight and body composition of race horses to optimise performance. [source] Impact of body fat mass extent on cardiac autonomic alterations in womenEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 8 2009J. Sztajzel Abstract Background, Obesity has been associated with significant abnormalities of the cardiac autonomic regulation. However, the precise impact of increasing body weight on cardiac autonomic function and the metabolic and hormonal contributors to these changes are presently unclear. The aim of our study was to explore in subjects with increasing values of body mass index (BMI) the alterations of cardiac autonomic function and to establish the potential role of various metabolic and hormonal contributors to these alterations. Materials and methods, We investigated time and frequency domain heart rate variability (HRV) parameters taken from 24-h Holter recordings, and several anthropometric, metabolic and hormonal parameters (plasma glucose, insulin, triglycerides, free fatty acids, leptin and adiponectin) in 68 normoglycaemic and normotensive women (mean age of 40 ± 3 years), subdivided according to their BMI into 15 normal body weight (controls), 15 overweight, 18 obese and 20 morbidly obese. Results, Heart rate was increased and HRV was decreased in the morbidly obese group as compared with controls. In overall population, a negative association linked body fat mass (FM) to HRV indices. None of the metabolic and hormonal parameters were significantly related to the HRV indices, after they were adjusted for the body FM. Conclusions, Morbidly obese, normoglycaemic and normotensive young women have increased HR and low HRV, indicating an abnormal cardiac autonomic function and representing a risk factor for adverse cardiovascular events. A decrease of HRV parameters is associated with a progressive increase of body FM. Other metabolic and hormonal factors, characterising obesity, do not show an independent influence on these HRV alterations. [source] Nutritional supplements combined with dietary counselling diminish whole body protein catabolism in HIV-infected patientsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 1 2000Berneis Background Weight loss and protein malnutrition are frequent complications in HIV-infected patients. The effect of an oral nutritional supplement combined with nutritional counselling on whole body protein metabolism was assessed. Materials and methods HIV-infected individuals with a body mass index < 21 kg m,2 or CD4-T cells < 500 , L,1 in stable clinical condition were randomly allocated to [ 1] receive either oral nutritional supplements (containing 2510 kJ, complete macro- and micronutrients) and dietary counselling (n = 8), or [ 2] identical monitoring but no supplements or specific nutritional advice (controls, n = 7). Whole body leucine kinetics and leucine oxidation rate were determined by [1,13C]-leucine infusions and lean and fat mass were measured before and 12 weeks after intervention. Results Leucine oxidation (protein catabolism) decreased in the group receiving nutritional intervention from 0.33 ± 0.02 to 0.26 ± 0.02 ,mol kg,1 min,1 after 12 weeks (P < 0.05; P < 0.05 vs. control group) but remained unchanged in the control group. Whole body leucine flux showed a tendency to decrease in the intervention group from 1.92 ± 0.19 to 1.73 ± 0.14 ,mol kg,1 min,1 (P = 0.07) and remained unchanged in the control group (2.21 ± 0.16 and 2.27 ± 0.14 ,mol kg,1 min,1, respectively). Lean body mass determined by bioelectrical impedance analysis increased in the nutritional intervention group from 84 ± 2 to 86 ± 2 per cent (P < 0.05) and fat mass decreased from 17 ± 2 to 14 ± 2 per cent (P < 0.05) of total body weight whereas neither mass changed in the control group. Nutritional intervention had no significant effect on lymphocyte CD4 counts, on plasma TNFR 55, TNFR 75 and ILR 2 concentrations and on quality of life. Conclusions The data demonstrate an anticatabolic effect of nutritional supplements combined with dietary counselling in HIV-infected subjects. They suggest that diminished whole body protein catabolism resulted in a change of body composition (increased lean mass, decreased fat mass). [source] Effects of ,-aminoisobutyric acid on leptin production and lipid homeostasis: mechanisms and possible relevance for the prevention of obesityFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 3 2010Karima Begriche Abstract ,-Aminoisobutyric acid (BAIBA) is a catabolite of thymine and antiretroviral thymine analogues AZT and d4T. We recently discovered that this ,-amino acid is able to enhance fatty acid oxidation and reduce body weight in mice through an increased production of leptin by the white adipose tissue (WAT). Furthermore, BAIBA could have favourable effects on nonalcoholic steatohepatitis in a leptin-independent manner. In the present review, we shall recall the circumstances that led us to discover the effects of BAIBA on body fat mass and lipid homeostasis. In addition, we put forward several hypothetical mechanisms whereby BAIBA could enhance leptin secretion by WAT and present some anti-inflammatory effects in the liver. We also discuss in this review (i) the deleterious impacts caused by the absence of, or low leptin expression on lipid homeostasis and body weight in humans and animals and (ii) recent data from other investigators suggesting that increasing leptin levels and/or responsiveness may be indeed an attractive pharmacological strategy in order to prevent (and/or treat) obesity, at least in some individuals. [source] Low Leptin Levels in Migraine: A Case Control StudyHEADACHE, Issue 7 2008Baburhan Guldiken MD Background., Obesity has been shown to be a risk factor for transformation of episodic migraine to chronic form, and adipocytokines have been implicated to modulate some of the cytokins such as interleukin-6 and tumor necrosis factor, which also act in the neurogenic inflammation in migraine. The aim of the study was to assess leptin levels, one of the adipocytokines, in headache-free period of migraine patients and investigate its relation to vascular risk factors. Material and Methods., Sixty-one patients with episodic migraine headaches and 64 control subjects were enrolled in the study. Demographic data and anthropometric measurements were obtained from all participants; body mass index and fat mass values were calculated. Glucose and lipid parameters were measured by oxidase technique and cholesterol esterase enzymatic assays, and leptin levels were measured by ELISA in serum samples obtained after an overnight fasting. Results., Leptin levels were found significantly lower in migraineurs than controls (40.1 ± 21.2 ng/mL, 48.5 ± 24.5 ng/mL; P < .05). Although body mass index did not differ between 2 groups, fat mass, and fat percentages were significantly lower in migraine patients (19.4 ± 8.8 kg, 26.0 ± 8.7 kg; P < .001 and 28 ± 9%, 34 ± 5%; P < .001, respectively). Conclusion., Migraine patients have low leptin levels and fat mass which may be related to the pathogenesis of migraine. The importance and impact of our findings on the prevalence, characteristics, and treatment of migraine needs to be investigated in further detailed studies. [source] No significant effect of uridine or pravastatin treatment for HIV lipoatrophy in men who have ceased thymidine analogue nucleoside reverse transcriptase inhibitor therapy: a randomized trial,HIV MEDICINE, Issue 8 2010A Calmy Background Lipoatrophy can complicate thymidine analogue nucleoside reverse transcriptase inhibitor (tNRTI)-based antiretroviral therapy (ART). Lipoatrophy may be less likely with ART including ritonavir-boosted lopinavir (LPV/r). Small, placebo-controlled studies found that uridine (in tNRTI recipients) and pravastatin improved HIV lipoatrophy over 12 weeks. Today, most patients with lipoatrophy receive non-tNRTI-based ART; the effect of uridine in such patients is unknown. Methods We performed a prospective, randomized trial in lipoatrophic adults with plasma HIV RNA<50 HIV-1 RNA copies/mL on tNRTI-sparing ART including LPV/r. Patients received uridine [36 g three times a day (tid) on 10 consecutive days per month; n=10], pravastatin [40 mg every night (nocte); n=12], uridine plus pravastatin (n=11) or neither (n=12) for 24 weeks. The primary endpoint was mean change in limb fat mass as assessed by dual-energy X-ray absorptiometry (DEXA). With 20 patients per intervention, the study had 80% power to detect a mean difference between a treatment and the control of 0.5 kg, assuming a standard deviation of 0.9 and an alpha threshold equal to 5% (two-sided). Results Of 45 participants (all men, with median age 49.5 years and median limb fat 2.6 kg), two discontinued pravastatin and one participant stopped both pravastatin and uridine. The difference between the mean changes in limb fat mass for uridine vs. no uridine was 0.03 kg [95% confidence interval (CI) ,0.35, +0.28; P=0.79]. The respective difference for pravastatin was ,0.03 kg (95% CI ,0.29, +0.34; P=0.84). Pravastatin slightly decreased total cholesterol (0.44 mmol/L; P=0.099). Visceral adipose tissue measured by computed tomography did not change significantly. Conclusion In this population and at the doses used, neither uridine nor pravastatin for 24 weeks significantly increased limb fat mass. [source] A randomized placebo-controlled trial of metformin for the treatment of HIV lipodystrophyHIV MEDICINE, Issue 7 2007R Kohli Objective We conducted a randomized placebo-controlled trial to examine the effects of metformin on visceral adipose tissue (VAT), appendicular fat, lipid profile and insulin sensitivity in HIV-infected persons with central adiposity and mild insulin resistance. Methods Forty-eight HIV-infected men and women with a self-reported increase in abdominal girth and an abnormal waist-to-hip ratio were randomly assigned in double-blind fashion to receive metformin 1500 mg or placebo daily for 24 weeks. Persons with diabetes were excluded. The following measures were obtained at baseline and 24 weeks: single-slice computed tomography (CT) scan, dual-energy X-ray absorptiometry (DEXA), lipid profile and oral glucose tolerance test. Results The median fasting insulin concentration of all participants was 12.3 ,U/mL. The percentage change in VAT was not significantly different between the metformin and placebo groups in univariate analysis and linear regression analysis adjusting for age, height, baseline VAT and insulin area under the curve (10.1% vs 3.2%; P=0.58). Metformin was associated with a significant decrease in appendicular fat mass compared with placebo (,686.0 vs 161.0 g; P=0.03). There was no significant change in lipid profile or insulin sensitivity between the two groups at 24 weeks. Conclusion Metformin should be used with caution in the treatment of HIV lipodystrophy, and, if used, should be reserved for persons with adequate peripheral fat and marked insulin resistance. [source] Muscle performance in patients with Crohn's disease in clinical remissionINFLAMMATORY BOWEL DISEASES, Issue 3 2005Jean-Baptiste Wiroth PhD Abstract Background: Because patients with Crohn's disease (CD) often show increased energy expenditure, nutritional deficiencies, and general fatigue, all which may persist after a flare, we hypothesized that CD could alter muscle mass and function. This study aimed to assess muscle strength and endurance in CD patients in clinical remission and the influencing factors. Methods: Forty-one outpatients (17 men and 24 women; age, 37 ± 10 yr), in remission (CD Activity Index < 150) for >3 months, and 25 age-matched healthy controls (10 men and 15 women; age, 37 ± 13 yr) were evaluated. Evaluation included a sit-up test, hand-grip strength test, hand-grip endurance test, lower limb strength test, and lower limb endurance test (LE), as well as a measure of physical activity. Results: No significant difference was found between CD and control groups regarding weight, height, body mass index, fat mass, and fat-free mass. Strength performance was lower in CD subjects compared with controls, particularly for lower limb indexes: lower limb strength test (,24.6%, P < 0.001), LE (,25.8%, P < 0.001), and sit-up test (,25.1%, P < 0.001). Previous disease severity, disease duration, the cumulative dose of glucocorticosteroids, current inflammation, and global habitual physical activity did not affect muscle performance. A recent use of steroids improved LE. Conclusions: CD patients in clinical remission have decreased muscle function that may affect their quality of life. This pattern is reflected by reduced strength and endurance indexes, particularly for lower limbs. The reasons for these changes need further study. Strength training should be assessed in these patients. [source] Body size and composition and colon cancer risk in womenINTERNATIONAL JOURNAL OF CANCER, Issue 6 2006Robert J. MacInnis Abstract Studies of colon cancer risk in males have reported strong positive associations with obesity, particularly with central adiposity. The association has been weaker and less consistent for women. In a prospective cohort study of women, body measurements were taken directly; fat mass and fat-free mass being estimated by bioelectrical impedance analysis and central adiposity by waist circumference and waist-to-hip ratio (WHR). Among 24,072 women followed on average for 10.4 years, 212 colon cancers were ascertained via the population cancer registry. We reviewed medical records of all cases and classified them according to anatomic site and stage. The central adiposity measures of WHR (hazard ratio per 0.1 unit increase = 1.31, 95% confidence interval (CI) 1.08,1.58) and waist circumference (hazard ratio per 10 cm increase = 1.14, 95% CI 1.02,1.28) were positively associated with colon cancer risk. There was little or no association between other anthropometric measures and risk of colon cancer. There was some evidence that the associations were stronger for proximal tumors, but no evidence that risk differed by stage for any of the anthropometric measures. Central adiposity appears to be associated with colon cancer risk in women. © 2005 Wiley-Liss, Inc. [source] The Cross-Sectional Relationship Between Body Mass Index, Waist,Hip Ratio, and Cognitive Performance in Postmenopausal Women Enrolled in the Women's Health InitiativeJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2010Diana R. Kerwin MD OBJECTIVES: To determine whether body mass index (BMI) is independently associated with cognitive function in postmenopausal women and the relationship between body fat distribution as estimated by waist-hip ratio (WHR). DESIGN: Cross-sectional data analysis. SETTING: Baseline data from the Women's Health Initiative (WHI) hormone trials. PARTICIPANTS: Eight thousand seven hundred forty-five postmenopausal women aged 65 to 79 free of clinical evidence of dementia who completed the baseline evaluation in the WHI hormone trials. MEASUREMENTS: Participants completed a Modified Mini-Mental State Examination (3MSE), health and lifestyle questionnaires, and standardized measurements of height, weight, body circumference, and blood pressure. Statistical analysis was performed of associations between 3MSE score, BMI, and WHR after controlling for known confounders. RESULTS: With the exception of smoking and exercise, vascular disease risk factors, including hypertension, waist measurement, heart disease, and diabetes mellitus, were significantly associated with 3MSE score and were included as covariables in subsequent analyses. BMI was inversely related to 3MSE score; for every 1-unit increase in BMI, 3MSE score decreased 0.988 points (P<.001) after adjusting for age, education, and vascular disease risk factors. BMI had the most pronounced association with poorer cognitive functioning scores in women with smaller waist measurements. In women with the highest WHR, cognitive scores increased with BMI. CONCLUSION: Higher BMI was associated with poorer cognitive function in women with smaller WHR. Higher WHR, estimating central fat mass, was associated with higher cognitive function in this cross-sectional study. Further research is needed to clarify the mechanism for this association. [source] Association Between Fitness and Changes in Body Composition and Muscle StrengthJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2 2010George A. Kuchel, [see editorial comments by Drs. Gustavo Duque, pp 37 OBJECTIVES: To examine the association between physical fitness, assessed according to ability and time to complete a 400-m walk, on changes in body composition and muscle strength over a 7-year period. DESIGN: Prospective observational cohort study. SETTING: Memphis, Tennessee, and Pittsburgh, Pennsylvania. PARTICIPANTS: Two thousand nine hundred forty-nine black and white men and women aged 70 to 79 participating in the Health, Aging and Body Composition Study. MEASUREMENTS: Body composition (fat and bone-free lean mass) was assessed using dual-energy X-ray absorptiometry in Years 1 to 6 and 8. Knee extension strength was measured using isokinetic dynamometry and grip strength using isometric dynamometry in Years 1, 2, 4, 6, and 8. RESULTS: Less fit people weighed more and had a higher total percentage of fat and a lower total percentage of lean mass than very fit men and women at baseline (P<.001). Additionally, the least fit lost significantly more weight, fat mass, and lean mass over time than the very fit (all P<.01). Very fit people had the highest grip strength and knee extensor strength at baseline and follow-up; decline in muscle strength was similar in every fitness group. CONCLUSION: Low fitness in old age was associated with greater weight loss and loss of lean mass than with high fitness. Despite having lower muscle strength, the rate of decline in the least fit persons was similar to that in the most fit. In clinical practice, a long-distance walk test as a measure of fitness might be useful to identify people at risk for these adverse health outcomes. [source] Association Between Testosterone and Estradiol and Age-Related Decline in Physical Function in a Diverse Sample of MenJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 11 2008Andre B. Araujo PhD OBJECTIVES: To examine the association between aging and physical function in men by testing a theoretically based model of aging, hormones, body composition, strength, and physical function with data obtained from men enrolled in the Boston Area Community Health/Bone (BACH/Bone) Survey. DESIGN: Cross-sectional, observational survey. SETTING: Population-based. PARTICIPANTS: Eight hundred ten black, Hispanic, and white randomly selected men from the Boston area aged 30 to 79. MEASUREMENTS: Testosterone, estradiol, sex hormone,binding globulin, lean and fat mass, grip strength, and summated index of physical function (derived from walk and chair stand tests). RESULTS: Measures of grip strength and physical function declined strongly with age. For instance, 10 years of aging was associated with a 0.49-point difference (scale 0,7) in physical function. Age differences in total testosterone and estradiol concentrations were smaller than age differences in their free fractions. Weak or nonsignificant age-adjusted correlations were observed between hormones and measures of physical function, although path analysis revealed a positive association between testosterone and appendicular lean mass and a strong negative association between testosterone and total fat mass. Lean and fat mass, in turn, were strongly associated with grip strength and physical function, indicating the possibility that testosterone influences physical function via indirect associations with body composition. CONCLUSION: The age-related decline in serum testosterone concentration in men has a weak association with physical strength and functional outcomes through its associations with lean and fat mass. [source] Functional Impact of Relative Versus Absolute Sarcopenia in Healthy Older WomenJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 11 2007Marcos Estrada MD OBJECTIVES: To determine whether adjustment of muscle mass for height2 or for body mass represents a more-relevant predictor of physical performance. DESIGN: Cross-sectional study, using baseline data from a trial comparing upper- and lower-body training. SETTING: Women recruited from the community and gynecological practices in Connecticut. PARTICIPANTS: One hundred eighty-nine healthy older (aged 67.5 ± 4.8), active women receiving estrogen for osteoporosis over 2 years. MEASUREMENTS: Total and appendicular skeletal muscle (ASM) and fat mass (AFM) were determined using dual x-ray absorptiometry. Physical performance, muscle strength, and fitness measures were obtained at baseline. RESULTS: Adjusting ASM for height2 identifies lean women who are sarcopenic according to published standards yet fails to identify overweight and obese women whose ASM adjusted for body mass is low. ASM divided by body mass (ASM/body mass) is a stronger physical performance predictor, explaining 32.5%, 13.5%, 11.6%, 6.3%, and 6.8% of the variance in maximum time on treadmill, 6-minute walk, gait speed, 8-foot walk, and single leg stance, respectively, whereas ASM divided by height in m2 (ASM/height2) explained only 2.9%, 0.2%, 2.0%, 0.04%, and 0.1%. Multivariate modeling demonstrated considerable overlap in aspects of ASM/body mass and AFM/body mass associated with performance, with ASM/body mass dominant. In contrast, ASM/height2 is a much stronger predictor of leg press 1 repetition maximum and maximum power. CONCLUSION: The results suggest that relative sarcopenia with ASM adjusted for body mass is a better mobility predictor, with absolute sarcopenia a better indicator of isolated muscle group function in healthy postmenopausal women receiving estrogen replacement. [source] Kidney Function as a Predictor of Loss of Lean Mass in Older Adults: Health, Aging and Body Composition StudyJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 10 2007Linda F. Fried MD OBJECTIVES: To assess the association between kidney function and change in body composition in older individuals. DESIGN: Prospective cohort study. SETTING: Two sites, Pittsburgh, Pennsylvania, and Memphis, Tennessee. PARTICIPANTS: Three thousand twenty-six well-functioning, participants aged 70 to 79 in the Health, Aging and Body Composition Study. MEASUREMENTS: Body composition (bone-free lean mass and fat mass) was measured using dual x-ray absorptiometry annually for 4 years. Kidney function was measured at baseline according to serum creatinine (SCr). Comorbidity and inflammatory markers were evaluated as covariates in mixed-model, repeated-measures analysis. RESULTS: High SCr was associated with loss of lean mass in men but not women, with a stronger relationship in black men (P=.02 for difference between slopes for white and black men). In white men, after adjustment for age and comorbidity, higher SCr remained associated with loss of lean mass (,0.07±0.03 kg/y greater loss per 0.4 mg/dL (1 standard deviation (SD)), P=.009) but was attenuated after adjustment for inflammatory factors (,0.05±0.03 kg/y greater loss per SD, P=.10). In black men, the relationship between SCr and loss of lean mass (,0.19±0.04 kg/y per SD, P<.001) persisted after adjustment for inflammation and overall weight change. CONCLUSION: Impaired kidney function may contribute to loss of lean mass in older men. Inflammation appeared to mediate the relationship in white but not black men. Future studies should strive to elucidate mechanisms linking kidney disease and muscle loss and identify treatments to minimize loss of lean mass and its functional consequences. [source] Testosterone Supplementation Therapy for Older Men: Potential Benefits and RisksJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 1 2003David A. Gruenewald MD Serum testosterone levels decline gradually and progressively with aging in men. Many manifestations associated with aging in men, including muscle atrophy and weakness, osteoporosis, reduced sexual functioning, and increased fat mass, are similar to changes associated with testosterone deficiency in young men. These similarities suggest that testosterone supplementation may prevent or reverse the effects of aging. A MEDLINE search was performed to identify studies of testosterone supplementation therapy in older men. A structured, qualitative review was performed of placebo-controlled trials that included men aged 60 and older and evaluated one or more physical, cognitive, affective, functional, or quality-of-life outcomes. Studies focusing on patients with severe systemic diseases and hormone deficiencies related to specific diseases were excluded. In healthy older men with low-normal to mildly decreased testosterone levels, testosterone supplementation increased lean body mass and decreased fat mass. Upper and lower body strength, functional performance, sexual functioning, and mood were improved or unchanged with testosterone replacement. Variable effects on cognitive function were reported, with improvements in some cognitive domains (e.g., spatial, working, and verbal memory). Testosterone supplementation improved exercise-induced coronary ischemia in men with coronary heart disease, whereas angina pectoris was improved or unchanged. In a few studies, men with low testosterone levels were more likely to experience improvements in lumbar bone mineral density, self-perceived functional status, libido, erectile function, and exercise-induced coronary ischemia with testosterone replacement than men with less marked testosterone deficiency. No major unfavorable effects on lipids were reported, but hematocrit and prostate specific antigen levels often increased. Based on these results, testosterone supplementation cannot be recommended at this time for older men with normal or low-normal testosterone levels and no clinical manifestations of hypogonadism. However, testosterone replacement may be warranted in older men with markedly decreased testosterone levels, regardless of symptoms, and in men with mildly decreased testosterone levels and symptoms or signs suggesting hypogonadism. The long-term safety and efficacy of testosterone supplementation remain uncertain. Establishment of evidence-based indications will depend on further demonstrations of favorable clinical outcomes and symptomatic, functional, and quality-of-life benefits in carefully performed, long-term, randomized, placebo-controlled clinical trials. J Am Geriatr Soc 51:101,115, 2003. [source] Resting energy expenditure and body composition of Labrador Retrievers fed high fat and low fat dietsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5-6 2006S. Yoo Summary A high dietary fat intake may be an important environmental factor leading to obesity in some animals. The mechanism could be either an increase in caloric intake and/or a decrease in energy expenditure. To test the hypothesis that high fat diets result in decreased resting energy expenditure (REE), we measured REE using indirect calorimetry in 10-adult intact male Labrador Retrievers, eating weight-maintenance high-fat (HF, 41% energy, average daily intake: 8018 ± 1247 kJ/day, mean ± SD) and low-fat (LF, 14% energy, average daily intake: 7331 ± 771 kJ/day) diets for a 30-day period. At the end of each dietary treatment, body composition measurements were performed using dual-energy X-ray absorptiometry. The mean ± SD REE was not different between diets (4940 ± 361 vs. 4861 ± 413 kJ/day on HF and LF diets respectively). Measurements of fat-free mass (FFM) and fat mass (FM) also did not differ between diets (FFM: 26.8 ± 2.3 kg vs. 26.3 ± 2.5 kg; FM: 3.0 ± 2.3 vs. 3.1 ± 1.5 kg on HF and LF diets respectively). In summary, using a whole body calorimeter, we found no evidence of a decrease in REE or a change in body composition on a HF diet compared with LF diet. 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