Inflammation and Fat Mass as Determinants of Changes in Physical Capacity and Mobility in Older Adults Displaying A Large Variability in Body Composition: The NuAge Study.

Background/Study context: Determining whether C-reactive protein (CRP), blood lipids, total and trunk fat mass (FM), and waist circumference (WC) are associated with changes in physical capacity over 3 years (Δ) in elderly. METHODS: One hundred twenty-two men and women 68-83 years of age participated in a 3-year follow-up study. Physical capacity was measured using five objective tests: (1) Timed Up and Go (TUG), (2) chair stand (CS), (3) normal walking speed (NWS), (4) fast walking speed (FWS), and (5) one-leg stand (LS), along with physical performance score (PPS) at baseline (T1) and 3 years later (T4). Total and trunk FM, WC, blood lipids, and CRP measured at baseline, were considered as potential predictors. RESULTS: At baseline, CRP and total FM were significantly correlated with all physical capacity tests, whereas trunk FM was correlated with CS and LS, and blood lipids only with FSW. No significant correlation was observed for WC. Total and trunk FM measured at baseline were correlated with ΔTUG and ΔPPS, whereas trunk FM and WC measured at baseline were correlated with ΔNWS. CRP and blood lipids, measured at baseline, were not associated with any changes over 3 years. At the end, WC measured at baseline was the strongest independent predictor for all physical capacity measures at baseline (T1), and ΔPPS measured over 3 years could be predicted by baseline WC. CONCLUSION: FM distribution seems more useful to determine physical capacity than inflammation. Interestingly, over a short follow-up of 3 years, WC significantly predicted changes in a composite score of physical activity. More studies are needed to elucidate factors that may influence physical capacity decline over time.

Effect of Resistance Training and Various Sources of Protein Supplementation on Body Fat Mass and Metabolic Profile in Sarcopenic Overweight Older Adult Men: A Pilot Study.

The decrease in resting energy expenditure (REE) and fat oxidation with aging is associated with an increase in fat mass (FM), and both could be prevented by exercise such as resistance training. Dairy consumption has also been shown to promote FM loss in different subpopulations and to be positively associated with fat oxidation. Therefore, we sought to determine whether resistance exercise combined with dairy supplementation could have an additive impact on FM and energy metabolism, especially in individuals with a deficit in muscle mass. Twenty-six older overweight sarcopenic men (65 ± 5 years old) were recruited for the study. They participated in 4 months of resistance exercise and were randomized into three groups for postexercise shakes (control, dairy, and nondairy isocaloric and isoprotein supplement with 375 ml and ~280 calories per shake). Body composition was measured by dual X-ray absorptiometry and REE by indirect calorimetry. Fasting glucose, insulin, leptin, inflammatory profile, and blood lipid profile were also measured. Significant decreases were observed with FM only in the dairy supplement group; no changes were observed for any other variables. To conclude, FM may decrease without changes in metabolic parameters during resistance training and dairy supplementation with no caloric restriction without having any impact on metabolic properties. More studies are warranted to explain this significant decrease in FM.

Effect of Resistance Training and Various Sources of Protein Supplementation on Body Fat Mass and Metabolic Profile in Sarcopenic Overweight Older Adult Men: A Pilot Study.

The decrease in resting energy expenditure (REE) and fat oxidation with aging is associated with an increase in fat mass (FM), and both could be prevented by exercise such as resistance training. Dairy consumption has also been shown to promote FM loss in different subpopulations and to be positively associated with fat oxidation. Therefore, we sought to determine whether resistance exercise combined with dairy supplementation could have an additive impact on FM and energy metabolism, especially in individuals with a deficit in muscle mass. Twenty-six older overweight sarcopenic men (65 ± 5 years old) were recruited for the study. They participated in 4 months of resistance exercise and were randomized into three groups for postexercise shakes (control, dairy, and nondairy isocaloric and isoprotein supplement with 375 ml and ~280 calories per shake). Body composition was measured by dual X-ray absorptiometry and REE by indirect calorimetry. Fasting glucose, insulin, leptin, inflammatory profile, and blood lipid profile were also measured. Significant decreases were observed with FM only in the dairy supplement group; no changes were observed for any other variables. To conclude, FM may decrease without changes in metabolic parameters during resistance training and dairy supplementation with no caloric restriction without having any impact on metabolic properties. More studies are warranted to explain this significant decrease in FM.

Is there a skeletal muscle mass threshold associated with the deterioration of insulin sensitivity in sedentary lean to obese postmenopausal women?

AIM: The purpose of this study was to determine an optimal cut-off point of skeletal muscle mass, using appendicular lean body mass (LBM) index, that identifies at risk individuals with deteriorated insulin sensitivity, using an established quantitative insulin sensitivity index (QUICKI) cut-off. METHODS: We performed a cross-sectional analysis in 231 lean and obese (BMI: 18.7-51.0 kg/m(2)) menopausal women. Fasting plasma glucose and insulin were obtained to calculate QUICKI as an index of insulin sensitivity. Skeletal muscle mass was measured as appendicular LBM by DXA and expressed as appendicular LBM index [appendicular LBM (kg)/height (m(2))]. Cut-offs were determined using receiver operating characteristic (ROC) curve analyses. RESULTS: The best cut-off value for skeletal muscle mass index to identify menopausal women with reduced insulin sensitivity was 7.025 kg/m(2) which had a sensitivity of 69.5% and specificity of 58.2%. CONCLUSION: Our results suggest that sedentary postmenopausal women with an appendicular skeletal muscle mass index above 7.025 kg/m(2) may be at greater risk of insulin resistance. Prospective studies are needed to validate our result.

Resistance training attenuates fat mass regain after weight loss in ovariectomized rats.

OBJECTIVE: The aim of the present study was to investigate the effects of maintaining only one of the two components of a food restriction (FR)+resistance training (RT) regimen on the regain of body weight and fat mass (liver and adipocytes) in ovariectomized (Ovx) rats. METHODS: Five week Ovx rats were submitted to a weight loss program consisting of a 26% FR combined with RT (OvxFR+RT) for 8 weeks. RT consisted of climbing a 1.5m vertical grid with a load attached to the tail, 20-40 times with progressively increasing loads 4 times/week. Following this weight loss intervention, OvxFR+RT rats were sub-divided into 3 groups for an additional 5 weeks: 2 groups went back to a normal ad libitum feeding with or without RT and the other group kept only FR. RESULTS: Combined FR+RT program in Ovx rats led to lower body mass gain, liver triacylglycerol (TAG) levels, and fat mass gain compared to sedentary normally fed Ovx rats (P<0.01). Stopping both FR and RT over a 5 week period resulted in the regain of body weight, intra-abdominal fat pad weight and liver TAG (P<0.01). When only FR was maintained, the regain of body and fat pad weight as well as liver and plasma TAG concentrations was completely prevented. However, when only RT was maintained, regain in the aforementioned parameters was attenuated but not prevented (P<0.05). CONCLUSION: It is concluded that following a FR+RT weight loss program, continuation of only RT constitutes an asset to attenuate body weight and fat mass regain in Ovx rats; although the impact is less than the maintaining FR alone. These results suggest that, in post-menopausal women, RT is a positive strategy to reduce body weight and fat mass relapse.

Liver of ovariectomized rats is resistant to resorption of lipids.

Ovarian hormones have been shown to regulate liver lipid accumulation in rats. The present study was designed to evaluate liver lipid resorption in ovariectomized (Ovx) rats. Ovx and sham-operated (Sham) rats were submitted to a high-fat (HF; 43% kcal fat as energy) diet for 5 weeks and then either maintained on this diet or switched to a standard (SD; 12.5% kcal fat as energy) diet till weeks 8 and 13 (n=8 rats/group). Body weight, energy intake, liver and intra-abdominal fat accumulation and plasma metabolic profile were determined. Body weight was significantly (P<0.01) higher in Ovx than in Sham groups at all times and switching diet did not alter the body weight pattern. The weight of the intra-abdominal fat depots and plasma leptin levels, along with liver triacylglycerol (TAG) concentrations, were significantly higher (P<0.01) in Ovx than in Sham rats. Switching diet reduced intra-abdominal fat depot weight and plasma leptin in all groups. Switching diet also resulted in a decrease in liver fat accumulation in Sham rats at all times. However, 8 weeks after the diet switch (week 13) liver fat accumulation was as high in Ovx rats as those maintained on the HF diet. When liver TAG values measured at week 13 were compared to initial pre-switching values (week 5), liver TAG levels in Ovx animals were maintained at the same level independently of the diet switch, while in Sham rats switching to a SD diet reduced liver TAG accumulation (P<0.05). The same comparisons with plasma TAG levels revealed an opposite relationship. These data suggest that liver lipid resorption in Ovx animals is more related to the ovarian hormone status than to the type of ingested diet.