PREDICTORS OF DECREASED SKELETAL MUSCLE MASS IN COMMUNITY-DWELLING OLDER ADULTS

Objective: To date, the actual prevalence of Skeletal muscle mass (SMM) loss by rigorous definition and its related factors have not been sufficiently surveyed in the community. We therefore examined the factors related to the reductions of skeletal muscle mass (SMM) in older adults. Design: Case-control study. Subjects: One hundred twenty four community-dwelling older adults aged ≥65 years participated. Measurements: Reductions of SMM were assessed by measuring difference between SMM at baseline and SMM 1 year later, by which participants were divided into three groups. Variables of the first tertile group, who had the greatest decrease in SMM, were compared with those of the second/third tertile groups. Variables included hight, weight, body mass index (BMI), maximal knee extension strength, grip strength, lower and upper muscle quality (UMQ), 5-m walking time (WT), timed up and go (TUG), food frequency questionnaire, mini nutritional assessment short form (MNA-SF), basic health checklist. A logistic regression analysis and classification and regression trees (CART) were used for multivariate analysis in order to extract variables that predicted reductions of SMM. Results: Significant differences were observed for age, SMM, UMQ, TUG, and WT between the first tertile and the second/third tertile groups, The CART analysis indicated that vitamin D intake UMQ and 5-m WT predicted significant decrease in SMM. Conclusion: The present study suggested a possibility that future reductions of SMM could be predicted by simple indices that may contribute to early detection of individuals at risk of developing sarcopenia in old age.