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

Area of Science:

• Neuroscience
• Gerontology
• Nutritional Science

Background:

• Cognitive decline is a growing concern in aging populations.
• The role of body composition, specifically muscle mass, in cognitive health requires further investigation.
• Apolipoprotein E ε4 allele (APOE4) status is a known risk factor for cognitive impairment.

Purpose of the Study:

• To investigate the relationship between mid-arm circumference (MAC) and calf circumference (CC) with cognitive performance.
• To examine the moderating effect of apolipoprotein E ε4 allele (APOE4) status on these associations.
• To explore the distinct roles of upper- and lower-limb muscle measurements in cognitive function.

Main Methods:

• Analysis of data from 196 older adults (65-90 years) in the General Lifestyle and AD (GLAD) study.
• Cognitive performance assessed using the CERAD neuropsychological battery, with episodic memory score (EMS) and non-memory score (NMS) as outcomes.
• Multiple linear regression analyses were performed, including interaction effects with APOE4 status.

Main Results:

• Higher MAC correlated with better episodic memory (EMS), while higher CC correlated with better non-memory cognition (NMS) (P_B < 0.0125).
• These associations were significant in APOE4-negative individuals but not in APOE4-positive individuals.
• Waist circumference (WC) showed no association with cognitive measures.

Conclusions:

• Upper- and lower-limb muscle mass may differentially influence cognitive domains, with MAC linked to episodic memory and CC to non-memory cognition.
• Muscle health maintenance could be a strategy for preserving cognitive function, particularly in APOE4-negative older adults.
• These findings contribute to understanding the interplay between physical health and cognitive aging.