Força muscular e sintomas depressivos entre idosos não institucionalizados do sul do Brasil: um estudo longitudinal

Abstract

The objective was to evaluate a bidirectional association between muscle strength and the presence of depressive symptoms among non-institutionalized elderly people in southern Brazil. Of the 1,451 elderly people aged 60 years and over interviewed in 2014, 537 were followed in 2019-20. In both years, those identified occurred in person, through a questionnaire on the sociodemographic situation, measurement of anthropometric measures and performance of physical tests. Muscle strength was measured at two moments using a digital manual dynamometer and the occurrence of depressive symptoms according to the Geriatric Depressive Scale (GDS-10). Elderly individuals with values below 33.8 kg for men and 18.9 kg for women were classified as having low muscle strength. Consider that depressive symptoms were present when a GDS-10 score of five or higher was reached. As covariates present in this study were included as assessed in the 2014 interview, as follows: gender, age, skin color, marital status, education, economic status, occupational status, diet quality, physical activity, smoking, muscle mass (BMI) and diagnosis of cardiovascular and cerebrovascular disease. Multivariate analyzes were used for associations between depressive symptoms and low muscle strength, and in order to investigate bidirectionality, a Cross-Lagged Panel Model (CLPM) analysis was used. It was observed that 14.1% of the elderly in 2014 had depressive symptoms, followed by 17.3% in 2019-20. Regarding low muscle strength, 25.8% were observed in 2014, and the increase increased to 37.7% in 2019-20. Statistically significant associations were observed between low muscle strength and the occurrence of depressive symptoms in both pieces of information. In 2014, the frequency of depressive symptoms in elderly people with low muscle strength was 1.5 times higher than among those with normal muscle strength [PR: 1.46 (CI95%: 1.24; 1.72); p<0.001]. Likewise, when verifying whether the probability of having low muscle strength was almost twice as high among those elderly with depressive symptoms than those classified without the condition [PR: 1.74 (CI95%: 1.34; 2.27) ; p<0.001]. There was no longitudinal association between low muscle strength and depressive symptoms. The measure of effect observed in the cross-sectional analysis with the variables collected in 2019-20 was lower than that observed in 2014. The measure of effect between the variables in the 2014 assessment was statistically diminished only among the younger elderly (<75 years) [RP = 1.68 (CI95%: 1.35; 2.08); p<0.001]. From this study, we emphasize the importance that the most opportune time is the beginning of old age to carry out actions that lead to a reduction in the loss of muscle strength inherent to age and the occurrence of depressive symptoms, acting through health promotion measures as a stimulus to healthy eating, physical activity, functional independence and social interaction. This volume is composed of the research project, followed by the fieldwork report, changes related to the research project, the original article and the publication rules of the journal The Journal of Nutrition, Health & Aging, for which the article composes this dissertation will be submitted.