Do the reduction of forced vital capacity (FVC), of forced expiratory volume in the first second (FEV1) and the ratio FEV1/FVC reduce muscle strength in the elderly?

Abstract

Aging is accompanied by changes in lung function, including the progressive decrease in forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) due to factors such as loss of lung elasticity, weakening of the breathing muscles, and reduction in the area of surface for alveolar gas exchange. Airflow limitation is one of the main causes of morbidity, functional limitations and mortality in adults aged 50 years and over and can potentially influence the process of neuromuscular strength loss with aging known as dynapenia, since the reduced oxygen supply for the whole body it affects cerebral oxygenation, motor unit recruitment and causes hypoxia, oxidative damage and compromised nutrient delivery to aging muscles. However, studies on the association between lung function and neuromuscular strength in the elderly are scarce.The present study aims to verify whether forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and the relationship between FEV1/FVC are associated with decreased neuromuscular strength in people over 50 years of age in 8 years of follow-up. This is a longitudinal study with 8,781 participants of the English Longitudinal Study of Ageing - ELSA in 8 years of follow-up. The study outcome will be lung function defined by FEV1 and FVC. Participants will be classified into two groups as low vs. FEV1. High FEV1 or Low FVC vs. High FVC, based on height adjustment and sex- and age-specific median (10 years). The exposure of interest will be the neuromuscular strength (in kg) obtained by the handgrip strength by dynamometry, considered as a continuous variable.Generalized linear mixed models controlled by socioeconomic factors, lifestyle, health conditions, neuropsychiatric factors, serum markers and functionality will be used. It is expected that the results of the present study show that, with aging, measurements of FEV1, FVC and the FEV1/FVC ratio are associated with a decrease in neuromuscular strength (dynapenia) and, as such, pulmonary function can be used as a possible indicator of the presence of dynapenia in the elderly.Descriptors: FEV1, FVC, Neuromuscular Strength, Aging, ELSA Study. (AU)