Body composition and 2-year cognitive change by sex among community-dwelling older adults: an exploratory analysis of the Korean Frailty and Aging Cohort Study

Ageing is accompanied by changes in both body composition and cognitive function; however, the reported associations between these changes have been inconsistent. We therefore examined whether total and regional fat mass and appendicular lean mass (ALM) were associated with 2-year changes across a range of cognitive measures, and whether these associations differed by sex among community-dwelling older adults in Korea. A total of 1,392 community-dwelling older adults (752 men and 640 women) from the Korean Frailty and Aging Cohort Study were included, using baseline data and 2-year follow-up assessments. Body composition was measured using dual-energy X-ray absorptiometry, and cognitive function was assessed using the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease Assessment Packet. Associations between baseline body composition and 2-year changes in cognitive function were examined using sex-stratified generalized linear models with a normal distribution and identity link, with adjustment for relevant covariates. Multiple comparisons were corrected using the Benjamini-Hochberg procedure. The mean age was 76.1 years in men and 74.9 years in women. Five associations reached nominal statistical significance. In women, higher total fat mass showed a nominal association with a more favorable 2-year change in TMT-A performance (B = -1.372; P = 0.018), and higher ALM showed a nominal association with a more favorable change in word-list recognition (B = 0.087; P = 0.010). In men, higher ALM showed nominal associations with more favorable changes in digit span total (B = 0.108; P = 0.027) and forward scores (B = 0.081; P = 0.025), whereas higher trunk fat mass showed a nominal association with a less favorable change in digit span total score (B = -0.092; P = 0.039). None of these associations remained statistically significant after correction for multiple comparisons. In this exploratory sex-stratified analysis, baseline body composition showed different patterns of association with 2-year cognitive change in men and women; however, no association remained statistically significant after correction for multiple comparisons. These findings should therefore be considered hypothesis-generating and require confirmation in cohorts with longer follow-up.