Comportamento sedentário, atividade física, aptidão física e massa muscular em idosos residentes em Alcobaça-BA

Abstract

The present study aimed to verify the association of reduced muscle mass in the elderly with the components of physical fitness, with sedentary behavior (CS) and physical activity (PA) in a combined and independent way. Cross-sectional study that is part of the Longitudinal Health Study for the Elderly of Alcobaça-BA (ELSIA). A total sample of 466 aged ≥ 60 years participated in the research. A global questionnaire was provided in the form of an individual interview with the aim of extracting sociodemographic information, health and behavioral indicators from these elderly people. PA and CS were acquired through the International Physical Activity Questionnaire (IPAQ). The Fullerton test battery was used as an instrument to assess the physical fitness components, evaluating the muscular strength and endurance of upper limbs (UL) and lower limbs (LL), dynamic balance and agility, flexibility of upper limbs and lower limbs and the composition body mass index (BMI). Muscle mass was assessed by calf circumference, with a cut-off point of 31 centimeters. The Poisson regression method with a robust estimator was used to calculate the prevalence ratio (PR) between SC, combined and independent PA level and the components of physical fitness with the presence of reduced muscle mass in the elderly. Reduced muscle mass was present in 13.3% of the sample, being predominant in individuals aged 60 to 69 years 37.1% (p ≤ 0.001). Regarding the components of physical fitness, the elderly who presented poor or moderate performance for muscular resistance UL and LL obtained a higher percentage of presenting reduced muscle mass (51.7% and 52.5% respectively p≤0.001). The CS combined with the level of PA demonstrated a significant association; individuals who reported excessive CS (≥ P75) but were sufficiently active obtained a higher probability of having reduced muscle mass both in the crude analysis (PR = 1.124; 95% CI: 1.005-1.258) and in the adjusted analysis (PR = 1.128; 95% CI: 1.012- 1.258), the group that had the longest duration in SC (≥P75) and was insufficiently active (<150min./week) also demonstrated a higher probability of reduced muscle mass in the analysis crude (PR = 1.077; 95% CI: 1041-1,114) and adjusted (PR = 1.098; 95% CI: 1.008-1.196). In the adjusted model, only the BMI variable remained significantly associated with reduced muscle mass, with low weight (PR = 1.342; 95% CI: 1.136-1.565) with a higher probability of reduced muscle mass and excess weight (PR = 0.829 ; 95% CI: 0.781-0.880) with greater probability of not having reduced muscle mass. Elderly individuals who had a sitting time ≥540.00 min./day regardless of following the PA level guidelines are more likely to have reduced muscle mass.