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.