Body Circumference and Cognitive Function: Role of Apolipoprotein E ε4 in the Elderly

This study examined the relationships between mid-arm circumference (MAC) and calf circumference (CC) with cognitive performance, considering the moderating effect of apolipoprotein E ε4 allele (<i>APOE4</i>) status. Data from 196 older adults (65-90 years) in the General Lifestyle and AD (GLAD) study were analyzed. Cognitive performance was assessed using the CERAD neuropsychological battery, with episodic memory score (EMS) and non-memory score (NMS) as primary outcomes. Multiple linear regression analyses examined associations between MAC, CC, and waist circumference (WC) with cognition, adjusting for key covariates. Interaction effects with <i>APOE4</i> status were also explored. Higher MAC (or MAC/WC) significantly correlated with better EMS, while higher CC (or CC/WC) correlated with better NMS, even after Bonferroni correction (<i>P_B</i> < 0.0125). These associations were stronger in <i>APOE4</i>-negative individuals but not significant in <i>APOE4</i>-positive participants. WC was not associated with cognitive measures. The results suggest that Upper- and lower-limb musculature may play distinct roles in cognitive function, with MAC linked to episodic memory and CC to non-memory cognition, particularly in <i>APOE4</i>-negative individuals. These findings highlight the potential of muscle health maintenance as a strategy for preserving cognitive function in aging populations.