Associations Between Fat and Lean Mass Indexes and Physical Performance in Prefrail and Frail Older Women.

Age-related changes in body composition have been associated with reduced physical performance. However, the relationship of fat and lean mass indexes with physical performance in the setting of frailty is yet to be clearly established. We investigated the association between fat and lean mass indexes and physical performance in prefrail and frail older women. Fifty-one community-dwelling women 65 years and older (mean age 76 years) were classified as prefrail or frail according to a modified frailty phenotype. Body composition was estimated by dual-energy X-ray absorptiometry, while physical performance was assessed via the following tests: Berg balance scale, timed-stands, timed up-and-go test, 6-minute walk test, and the short performance physical battery. Correlation coefficients were determined to assess the association between body composition and physical performance parameters. Associations between continuous variables with a p-value <0.05 were included in a linear regression analysis. All fat mass indexes predicted a reduced performance in at least one functional test. Among the lean mass indexes, only leg lean mass adjusted by body fat mass was directly associated with better physical performance. Our findings indicate that fat mass indexes may have a greater impact on physical performance than lean mass in frail and prefrail older women.

Number of high-protein containing meals correlates with muscle mass in pre-frail and frail elderly.

BACKGROUND: Aging is accompanied by the inability to optimally respond to anabolic stimulus of nutrition, with consequent loss of muscle mass and functionality. It has been speculated that not only total protein intake, but also the per meal protein dose may have important implications to protein balance and, hence, muscle mass in middle-aged and older adults, but evidence is lacking in a more vulnerable population such as the frail elderly. The aim was to investigate possible associations between total protein intake and its per meal dose with multiple measures of muscle mass, strength, and functionality in a cohort of pre-frail and frail elderly individuals. METHODS: One-hundred-and-fifty-seven pre-frail and frail elderly individuals were assessed for total and per meal protein intake (food diaries), total and appendicular lean mass (DXA), vastus lateralis cross-sectional area [(CSA) B-mode ultrasound], and muscle function [leg-press and bench press 1-RM, timed-stands test, timed-up-and-go test, handgrip, and risk of falls (Biodex Balance System®)]. RESULTS: Protein intake and number of meals with either ≥20 g or ≥30 g of protein were significantly associated (after controlling for confounding factors) with greater total and appendicular lean mass and vastus lateralis CSA. CONCLUSIONS: We found that not only total protein intake but also the number of high-protein containing meals are associated with muscle mass in frail and pre-frail elderly.

Different protein and derivatives supplementation strategies combined with resistance training in pre-frail and frail elderly: Rationale and protocol for the "Pro-Elderly" Study.

BACKGROUND: Frailty is a multifactorial geriatric syndrome characterized by progressive decline in health and associated with decreased muscle mass, strength, and functional capacity. Resistance training (RT) combined with protein or amino acids supplementation has been shown to be promising for mitigating age-related impairments. AIM: To investigate the chronic effects of different strategies of protein and derivatives supplementation in association with RT on selected health-related parameters in pre-frail and frail elderly. METHODS: This is a series of double-blind, randomized, placebo-controlled, parallel-group clinical trials. Volunteers will be divided into nine groups, comprising four different sub-studies evaluating the effects of: isolated leucine supplementation (study 1); protein source (whey vs. soy - study 2); combination of whey protein and creatine (study 3); and sexual dimorphism on the response to protein intake and RT (males vs. females - study 4). Muscle cross-sectional area, fiber cross-sectional area, body composition, lower-limb maximal dynamic and isometric strength, functionality, lipid profile, biochemical parameters, renal function, quality of life, and nutritional status will be assessed before and after a 16-week intervention period. Data will be tested for normality and a mixed-model for repeated measures will be conducted to assess within- and between-group effects of the intervention on the dependent variables. Confidence intervals (95%), effect sizes, and relative changes will also be determined, with significance set at p < 0.05.