Força de Preensão Manual em idosos comunitários: prevalência, proposição de equação preditiva e associação com ângulo de fase

Abstract

The aging process is associated with a decrease in functional capacity, which manifests heterogeneously among the elderly, with implications for health. Among the changes observed over time, the reduction in skeletal muscle contributes to a decrease in muscle strength, and the handgrip strength (HGS) measurement is useful in predicting overall muscle strength and functionality. Thus, this thesis aimed to study HGS in community-dwelling older adults. The methodological considerations are divided into two parts: a systematic review, which followed the recommendation of the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA), and whose search was performed in four databases (PubMed, SciELO, LILACS and Embase), with a meta-analysis and subgroup analysis; and the second part of the methodological aspects, involving a cross-sectional study, with a representative sample, carried out with older adults from the Primary Health Care (PHC) of a municipality in the northeast of Brazil. The results of the thesis are presented in the form of three scientific articles. The first aimed to estimate the frequency of a low HGS among community-dwelling older adults in Latin America (LA) through a systematic review and meta-analysis and identified 53 eligible studies. The summary measure of the prevalence of a low HGS among the older adults in LA was 33.0% (95% CI 29.0-36.0%), with Cuba showing the highest estimated prevalence and Colombia the lowest. The prevalence was higher among women than men and in the analysis according to sample size and risk of bias score, the prevalence obtained did not seem to be influenced by less robust studies. The second article aimed to elaborate prediction equations for HGS in older adults in PHC (n=316). The results showed that the variables sex, age and knee height together explained more than 50% of the variation in HGS (p < 0.001), composing the equation for both the right and left hand. There was agreement between the measured and estimated HGS, evaluated by the Bland-Altman diagram. Finally, the third article investigated the association between HGS and the standardized phase angle (SPA) in older adults from PHC. Of the 296 individuals evaluated, 28.0% showed a low HGS and 15.9% had a SPA < -1.65°. The analysis showed that a SPA < -1.65° increases the chance of the older adults having a low HGS, both unadjusted (OR = 2.71; 95% CI 1.43-5.15) and in the final model (OR = 2.35; 95% CI 1.14- 4.87). The results of this thesis contribute to widening the debate on HGS, identifying a significant prevalence of a low HGS in LA, and they point to the possibility of using simple parameters frequently used in the assessment of older adults to explain variability in HGS. Thus, the importance of this parameter is reinforced as an indicator of functionality in gerontology, especially in the context of PHC.