Sex-moderated association between body composition and cognition in older adults

Background: Some studies have reported an association between body composition and cognition in older adults, but underlying mechanisms and physiological factors remain poorly understood. Moreover, sex-related differences in metabolic health and age-related cognitive decline have gained major interest lately. The present study investigated the potential moderating effect of sex on the relationship between body composition and cognition in older adults. Methods: Global cognition, assessed by the Montreal Cognitive Assessment (MoCA), and body composition, measured using dual-energy x-ray absorptiometry (DXA), were analyzed in 155 women and 65 men aged 60 years old or more. Moderation analyses were computed to determine if sex moderates the effect of the different body composition parameters on the MoCA while controlling for the body mass index and the level of education of the participants. Results: Sex moderated the association between total lean mass, trunk lean mass, arms lean mass, and the MoCA score. These body composition parameters were positively associated with cognition only in men. Fat mass was not associated with cognition in any sex. Conclusion: Overall, higher lean mass and in particular trunk and arms lean mass was associated with higher cognitive abilities in older men. Longitudinal studies or intervention studies are needed to further identify physiological mechanisms that sustain the relationship between lean mass and cognition.