Bidirectional relationship between cognitive function, muscle mass, and physical activity level in older adults in rural Ecuador

Population aging in rural settings increases the risk of functional dependence and cognitive impairment, making it necessary to identify early modifiable markers in community clinical practice. The objective of this study was to determine the bidirectional relationship between cognitive function, skeletal muscle mass indices, and physical exercise level in older adults residing in rural communities in Ecuador. A cross-sectional study was conducted with 316 participants (99 men and 217 women) over 65 years of age, assessing body composition using electrical bioimpedance, cognitive function with the Mini-Mental State Examination (MMSE) in Spanish, and physical activity level through the exercise subscale of the PEPS-I instrument. Data were analyzed using Spearman correlation and binary logistic regression models adjusted for sociodemographic and baseline health factors. A significant correlation was found between exercise and MMSE (r?=?0.225; p?<?.001). A low exercise level predicted a higher risk of cognitive impairment (OR?=?2.41; 95% CI: 1.56-3.83), while cognitive impairment predicted a low physical activity level (OR?=?2.40; 95% CI: 1.57-3.94). No significant associations were found between muscle mass indices and cognitive function. It is concluded that there is a clear bidirectional relationship between cognitive decline and low physical activity in rural older adults, highlighting the need for comprehensive clinical interventions that simultaneously address both domains to preserve functional autonomy in this vulnerable population.