Lean mass, muscle strength, and physical function in a diverse population of men: a population-based cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Age-related declines in lean body mass appear to be more rapid in men than in women but our understanding of muscle mass and function among different subgroups of men and their changes with age is quite limited. The objective of this analysis is to examine racial/ethnic differences and racial/ethnic group-specific cross-sectional age differences in measures of muscle mass, muscle strength, and physical function among men.</p> <p>Methods</p> <p>Data were obtained from the Boston Area Community Health/Bone (BACH/Bone) Survey, a population-based, cross-sectional, observational survey. Subjects included 1,157 black, Hispanic, and white randomly-selected Boston men ages 30-79 y. Lean mass was assessed by dual-energy x-ray absorptiometry. Upper extremity (grip) strength was assessed with a hand dynamometer and lower extremity physical function was derived from walk and chair stand tests. Upper extremity strength and lower extremity physical function were also indexed by lean mass and lean mass was indexed by the square of height.</p> <p>Results</p> <p>Mean age of the sample was 47.5 y. Substantial cross-sectional age differences in grip strength and physical function were consistent across race/ethnicity. Racial/ethnic differences, with and without adjustment for covariates, were evident in all outcomes except grip strength. Racial differences in lean mass did not translate into parallel differences in physical function. For instance, multivariate modeling (with adjustments for age, height, fat mass, self-rated health and physical activity) indicated that whereas total body lean mass was 2.43 kg (approximately 5%) higher in black compared with white men, black men had a physical function score that was approximately 20% lower than white men.</p> <p>Conclusions</p> <p>In spite of lower levels of lean mass, the higher levels of physical function observed among white compared with non-white men in this study appear to be broadly consistent with known racial/ethnic differences in outcomes.</p

Dietary factors associated with metabolic syndrome in Brazilian adults

<p>Abstract</p> <p>Background</p> <p>Metabolic Syndrome (MS) is defined as the association of numerous factors that increase cardiovascular risk and diet is one of the main factors related to increase the MS in the population. This study aimed to evaluate the association of diet on the presence of MS in an adult population sample.</p> <p>Methodology</p> <p>305 adults were clinically screened to participate in a lifestyle modification program. Anthropometric assessments included waist circumference (WC), body fat and calculated BMI (kg/m²) and muscle-mass index (MMI kg/m²). Dietary intake was estimated by 24 h dietary recall. Fasting blood was used for biochemical analysis. MS was diagnosed using NCEP-ATPIII (2001) criteria with adaptation for glucose (≥ 100 mg/dL). Logistic regression (Odds ratio) was performed in order to determine the odds ratio for developing MS according to dietary intake.</p> <p>Results</p> <p>An adequate intake of fruits, OR = 0.52 (CI:0.28-0.98), and an intake of more than 8 different items in the diet (variety), OR = 0.31 (CI:0.12-0.79) showed to be a protective factor against a diagnosis of MS. Saturated fat intake greater than 10% of total caloric value represented a risk for MS diagnosis, OR = 2.0 (1.04-3.84).</p> <p>Conclusion</p> <p>Regarding the dietary aspect, a risk factor for MS was higher intake of saturated fat, and protective factors were high diet variety and adequate fruit intake.</p

Apparent decreased oxidation and turnover of leucine during infusion of medium-chain triglycerides.

A potential effector of the protein-sparing adaptation to fasting could be the increased availability of endogenous long-chain fatty acids. Were this hypothesis correct, infusion of medium-chain triglycerides to increase the plasma concentration of medium-chain fatty acids might also result in protein sparing. However, in most in vitro studies in rat muscle, octanoate increases the oxidation of the essential amino acid leucine. Therefore leucine metabolism was assessed with infusions of [3H]leucine and a-[14C]ketoisocaproate ([14C]KIC) before and during an infusion of trioctanoin in conscious dogs. Plasma octanoate increased from less than 30 to 528 microM over the 3 h of infusion. Plasma leucine and KIC concentrations decreased by 65-70% (P less than 0.01) over the first 2 h of infusion. Leucine oxidation, estimated from the expired 14CO2 and the plasma [14C]KIC specific activity, as well as from an open two-pool model, decreased. By use of these isotope models, the rates of leucine coming from and going to protein decreased (P less than 0.05 to P less than 0.01). Interconversion of leucine and KIC estimated from the open two-pool model decreased by 80% (P less than 0.01). These changes were accompanied by a 36% decrease in the plasma concentration of total plasma amino acids. Within the confines of the isotope models employed, these data are consistent with the hypothesis that increased fatty acid oxidation decreases protein turnover and may spare essential amino acids

Weightlessness as an accelerated model of nutritional disturbances

Food intake and eating patterns, body functions and composition are significantly altered by short-duration space flight. Prolonged missions lasting weeks or months further aggravate these changes, and are responsible for acute or chronic physical impairments at return to ground conditions. Current projects of missions to Mars, resulting in 2 years of microgravity conditions, stress the critical need for the development of optimal nutritional programs and physical countermeasures to prevent body mass and function alterations. This review outlines ground models of microgravity simulation, summarizes the major effects of weightlessness on body composition, protein metabolism, hormonal pattern, and muscle function, and addresses contradictory findings related to the oxidative stress secondary to space flight. Potential countermeasures, such as nutrient intake and physical conditioning, as well as areas of interest for future research both in ground and space medicine, are discussed

Low cost measurement of body composition with oxygen-18 enriched water

International audienc

Dietary trans alpha-linolenic acid from deodorised rapeseed oil and plasma lipids and lipoproteins in healthy men: the TransLinE Study.

: Br J Nutr 2001 Mar;85(3):387-92 Related Articles, Books, LinkOut Comment in: Br J Nutr. 2001 Mar;85(3):249-50. Dietary trans alpha-linolenic acid from deodorised rapeseed oil and plasma lipids and lipoproteins in healthy men: the TransLinE Study. Vermunt SH, Beaufrere B, Riemersma RA, Sebedio JL, Chardigny JM, Mensink RP, TransLinE Investigators a. Maastricht University, Department of Human Biology, Maastricht, The Netherlands. TRANS: isomers of alpha-linolenic acid, which are formed by deodorization of refined vegetable oils, can be found in significant amounts in edible oils. Effects of trans alpha-linolenic acid on plasma lipoproteins are unknown. We therefore investigated the effects of trans alpha-linolenic acid on plasma lipids and lipoproteins in healthy European men. Eighty-eight healthy men from three European countries (France, Scotland, UK and the Netherlands) first consumed for 6 weeks a diet with experimental oils 'free' of trans fatty acids (run-in period). For the next 6 weeks, they were randomly allocated to a diet with experimental oils 'high' or 'low' in trans alpha-linolenic acid. Daily total trans alpha-linolenic acid intake in the high trans group was 1410 (range 583-2642) mg. Experimental oils were provided as such, or incorporated into margarines, cheeses, muffins and biscuits. The high trans alpha-linolenic acid diet significantly increased the plasma LDL-:HDL-cholesterol ratio by 8.1 % (95 % CI 1.4, 15.3; and the total cholesterol:HDL-cholesterol ratio by 5.1 % (95 % CI 0.4, 9.9; compared with the low-trans diet. This was largely explained by an increase in LDL-cholesterol on the high-trans diet, while no change was observed in the low-trans group (mean treatment effect of 4.7 % (95 % CI -0.8, 10.5; No effects were found on total cholesterol and HDL-cholesterol, triacylglycerols, apolipoprotein B and A-1, and lipoprotein(a) concentrations. In conclusion, trans alpha-linolenic acid may increase plasma LDL-:HDL-cholesterol and total cholesterol:HDL-cholesterol ratios. Whether diet-induced changes in these ratios truly affects the risk for CHD remains to be established