Physical activity, protein consumption, and loss of muscle mass in older adult participants of the ELSA-Brazil study

Abstract

Objective: The objective was to evaluate the relationship between protein consumption, physical activity, and muscle mass in individuals aged ≥ 60 years. Methods: This prospective study was based on the baseline and second wave of the ELSA-Brazil study. Protein consumption was assessed using a semiquantitative food frequency questionnaire. Physical activity was measured using the International Physical Activity Questionnaire. Muscle mass was estimated using a prediction equation, and the difference in MM between the first and second waves was calculated. Bivariate analyses were performed, with p < 0.05 considered significant. Multivariate analysis consisted of 4 Poisson regression models including covariates with p < 0.20. The statistical analysis was performed in IBM SPSS Statistics 21. Results: The sample included 2216 older adults, 55.10% of whom were women, with a mean age of 65.20 (SD, 4.15). Participants whose muscle mass decreased between the waves were in the first quartile of protein consumption. Mean physical activity significantly differed between the groups, while leisure-time physical activity differed only for women (p < 0.05). After adjusting for sociodemographic, health, and lifestyle variables, participants with lower protein intake had a 1.45 (1.29–1.63) relative risk of muscle mass loss. Conclusions: Lower protein consumption and higher physical activity were associated with decreased muscle mass, and those with protein consumption in the first and second quartiles are at higher risk of muscle mass loss.