Longitudinal associations between body composition, sarcopenic obesity and outcomes of frailty, disability, institutionalisation and mortality in community-dwelling older men: The Concord Health and Ageing in Men Project

Background: to explore the longitudinal associations between body composition measures, sarcopenic obesity and outcomes of frailty, activities of daily living (ADL) and instrumental ADL (IADL) disability, institutionalisation and mortality. Methods: men aged ≥ 70 years (2005-07) from the Concord Health and Ageing in Men Project were assessed at baseline (n = 1,705), 2 (n = 1,366) and 5 years (n = 954). The main outcome measures were frailty (adapted Fried criteria), ADL, including personal care and mobility and IADL disability (ability to perform tasks for independent living), institutionalisation and mortality. The Foundation for the National Institutes of Health cut-points were used for low muscle mass: appendicular lean mass (ALM):Body Mass Index (BMI) ratio (ALMBMI) <0.789 and obesity was defined as >30% fat. Generalised estimating equations were used to examine the longitudinal associations between the independent variables (obesity alone, low muscle mass and sarcopenic obesity) and frailty, ADL and IADL disability. Results: in unadjusted, age adjusted and fully adjusted analysis, men with low muscle mass showed increased risk of frailty and IADL disability. In fully adjusted analysis, men with sarcopenic obesity had an increased risk of frailty (odds ratio (OR): 2.00 (95% confidence of interval (CI): 1.42, 2.82)) ADL disability (OR: 1.58 (95% CI: 1.12, 2.24)) and IADL disability (OR: 1.36 (95% CI: 1.05, 1.76)). Obesity alone was protective for institutionalisation (OR: 0.51 (95% CI: 0.31, 0.84)) but was not associated with any other outcomes. Conclusions: low muscle mass and sarcopenic obesity were associated with poor functional outcomes, independent of confounders. This would suggest that future trials on frailty and disability prevention should be designed to intervene on both muscle mass and fat mass.