Effects of a vitamin D and leucine-enriched whey protein nutritional supplement on measures of sarcopenia in older adults, the PROVIDE study: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Age-related losses of muscle mass, strength, and function (sarcopenia) pose significant threats to physical performance, independence, and quality of life. Nutritional supplementation could positively influence aspects of sarcopenia and thereby prevent mobility disability. OBJECTIVE: To test the hypothesis that a specific oral nutritional supplement can result in improvements in measures of sarcopenia. DESIGN: A multicenter, randomized, controlled, double-blind, 2 parallel-group trial among 380 sarcopenic primarily independent-living older adults with Short Physical Performance Battery (SPPB; 0-12) scores between 4 and 9, and a low skeletal muscle mass index. The active group (n = 184) received a vitamin D and leucine-enriched whey protein nutritional supplement to consume twice daily for 13 weeks. The control group (n = 196) received an iso-caloric control product to consume twice daily for 13 weeks. Primary outcomes of handgrip strength and SPPB score, and secondary outcomes of chair-stand test, gait speed, balance score, and appendicular muscle mass (by DXA) were measured at baseline, week 7, and week 13 of the intervention. RESULTS: Handgrip strength and SPPB improved in both groups without significant between-group differences. The active group improved more in the chair-stand test compared with the control group, between-group effect (95% confidence interval): -1.01 seconds (-1.77 to -0.19), P = .018. The active group gained more appendicular muscle mass than the control group, between-group effect: 0.17 kg (0.004-0.338), P = .045. CONCLUSIONS: This 13-week intervention of a vitamin D and leucine-enriched whey protein oral nutritional supplement resulted in improvements in muscle mass and lower-extremity function among sarcopenic older adults. This study shows proof-of-principle that specific nutritional supplementation alone might benefit geriatric patients, especially relevant for those who are unable to exercise. These results warrant further investigations into the role of a specific nutritional supplement as part of a multimodal approach to prevent adverse outcomes among older adults at risk for disability.

Effects of strength training versus power training on physical performance in prefrail community-dwelling older adults.

BACKGROUND: It has been unclear which training mode is most effective and feasible for improving physical performance in the risk group of prefrail community-dwelling older adults. OBJECTIVE: The purpose of the present study was to compare the effects of strength training (ST) versus power training (PT) on functional performance in prefrail older adults. This study was registered at clinicaltrials.gov as NCT00783159. METHODS: 69 community-dwelling older adults (>65 years) who were prefrail according to the definition of Fried were included in a 12-week exercise program. The participants were randomized into an ST group, a PT group and a control group. All participants were supplemented with vitamin D(3) orally before entering the intervention period. The primary outcome was the global score on the Short Physical Performance Battery (SPPB). Secondary outcomes were muscle power, appendicular lean mass (aLM) measured by dual energy X-ray absorptiometry and self-reported functional deficits (Short Form of the Late-Life Function and Disability Instrument, SF-LLFDI). RESULTS: Regarding changes in the SPPB score during the intervention, significant heterogeneity between the groups was observed (p = 0.023). In pair-wise comparisons, participants in both training groups significantly (PT: p = 0.012, ST: 0.009) increased their SPPB score (PT: Δ(mean) = 0.8, ST: Δ(mean) = 1.0) compared to the control group, with no statistical difference among training groups (p = 0.301). No statistical differences were found in changes in aLM (p = 0.769), muscle power (p = 0.308) and SF-LLFDI (p = 0.623) between the groups. Muscle power significantly increased (p = 0.017) under vitamin D(3) intake. CONCLUSIONS: In prefrail community-dwelling adults, PT is not superior to ST, although both training modes resulted in significant improvements in physical performance. With regard to dropout rates, ST appears to be advantageous compared to PT. The high prevalence of vitamin D(3) deficiency and the slight improvement of physical performance under vitamin D(3) supplementation among study participants underline the relevance of this approach in physical exercise interventions.