The association of aerobic and muscular fitness with cognitive impairment: Findings from a nationally representative survey

Abstract

This study aimed to characterize the combined association between cardiorespiratory fitness (CRF), muscular strength, and cognitive outcomes in middle-aged and older adults from low and middle-income countries (LMICs). We analyzed cross-sectional, population-based data from adults aged 50 years or older from six LMICs. Mild cognitive impairment (MCI) was defined according to the National Institute on Aging‐Alzheimer's Association criteria. Estimated CRF (eCRF) was calculated using previously validated, sex-specific equations. Handgrip strength (HS) was used as an indicator of muscular strength. We used linear and robust Poisson regression models to examine the associations between eCRF, HS, and MCI. Data from 28,339 adults (63.1 [9.5] years) were analyzed. Participants with low eCRF (PR: 1.45; 95%CI: 1.11, 1.90) and HS (PR: 1.92; 95%CI: 1.79, 2.04) were more prone to have MCI. Participants with low HS showed higher likelihood of MCI than those with preserved HS through the CRF range; however, this difference was not seen among highly fit individuals (10 METs or higher). Each 1-MET (PR: 0.77; 95%CI: 0.67, 0.86) and 5-kgf (PR: 0.63; 95%CI: 0.48, 0.79) increase was associated with a reduction in the likelihood of MCI. eCRF and HS were strongly and independently associated with MCI in middle-aged and older adults.