Prevalência da sarcopenia e fatores associados: um estudo com idosos longevos do contexto amazônico

Abstract

Aging is a physiological, progressive process that occurs in all human beings and involves biological, cultural, and social changes. It can be understood both subjectively, at the individual level of how each person experiences this process, and objectively, through biopsychosocial alterations. This natural phenomenon progresses throughout the life course, affecting multiple systems and leading to modifications in the organism, including a reduction in muscle mass and muscle strength. Sarcopenia, characterized primarily by decreased muscle strength, is frequently observed in the older population. However, there is a lack of scientific evidence addressing this biological alteration in specific populations, particularly among the oldest old living in riverine and rural areas of Manaus, Amazonas State, Brazil. Thus, the aim of this study was to investigate the prevalence of sarcopenia and associated factors in the oldest old in the Amazonian context. A population-based, cross-sectional epidemiological study was conducted with 111 oldest old individuals (≥80 years) residing in rural and riverine communities of Manaus (AM). All data collection was carried out in the participants’ homes, with support from the Primary Health Care Network (DISA Rural), Community Health Agents, and local Primary Health Units, and followed a Multidimensional Assessment Protocol that examined sociodemographic characteristics, cognitive status using the Mini-Mental State Examination, health conditions/lifestyle habits, and functional capacity. Sarcopenia was defined according to EWGSOP2 criteria, using handgrip dynamometry (muscle strength), electrical bioimpedance (muscle mass), and usual gait-speed test (physical performance). The overall prevalence of sarcopenia was 64.5% in the sample of 111 oldest old, with higher frequencies in women (68.1%) compared with men (51.0%). Basic Activities of Daily Living (BADL), assessed by the Katz Index, did not differentiate the groups, whereas Instrumental Activities of Daily Living (IADL), measured by the Lawton Scale, were worse among sarcopenic individuals. In the model, each one-point increase in the Lawton score was associated with a 36% reduction in the odds of sarcopenia (OR=0.64; 95%CI 0.53–0.78). There was also an association between cognitive impairment and sarcopenia (OR=2.23; 95%CI 1.00–4.98). Conversely, some morbidities such as diabetes, arthritis/rheumatism, and osteoarthritis were not associated with the outcome. In conclusion, this study showed a high prevalence of sarcopenia, with a greater impact among women. Furthermore, IADL-related functionality and cognition emerge as central axes for screening and prioritizing care in the oldest old in the Amazon, guiding operational strategies in rural and riverine territories.