Physical fitness, body composition and cognition profiles in older adults: A sex-specific perspective

Introduction: Numerous clinical studies demonstrate that higher physical fitness correlates with healthier body composition and better cognitive functions in older adults. Yet, it remains unclear whether these links are domain-specific and how they vary between sexes. This cross-sectional study investigated the interrelations between physical fitness, body composition, and distinct cognitive domains in community-dwelling older adults. Methods: The population consisted of 157 older adults (39 men/118 women, mean age 68 ± 6 years). Physical fitness was evaluated via maximal and preferred walking speed tests (WSmax, WSpref), functional lower-limb strength by 5-time Sit-to-Stand, 5STS, and upper-limb strength by hand grip dynamometry. Body composition (lean body mass, fat mass, visceral adiposity/VAT) was measured (bioelectrical impedance, OMRON BF511). Cognitive status was assessed using standardized tests (ACE-R, AVLT, TMT-A/B, DSST). Cognitive flexibility (TMT B-A), psychomotor speed (TMT B/A), and executive composite score (ECS) derived from standardized z-scores of TMT-B and DSST (Zscore=((-1)*ZTMTB time+Z DSST_score)/(2)) were calculated. Results: 5STS performance demonstrated the most robust association with global cognition (ACE-R, R=0.41, p<0.01). Sex-specific analyses revealed distinct patterns: in women, ECS correlated positively with hand grip strength (r=0.54, p=0.0004) and negatively with visceral adiposity (r=-0.23, p=0.033). In men, ECS was linked to visceral adiposity (r=-0.55, p=0.01) and lean body mass (r=0.56, p=0.01). Additionally, higher visceral adiposity in men correlated with reduced psychomotor speed (TMT B/A; r=-0.46, p=0.05) and higher TMT B-A difference scores (TMT B-A; r=0.49, p=0.03), indicating decreased cognitive flexibility. Slower WSmax was strongly associated with reduced psychomotor speed (r=0.60, p=0.006). Furthermore, k-means cluster analysis incorporating global cognition (ACE-R), a metabolic risk marker (visceral adiposity), and functional performance (5STS and WSpref) stratified our cohort into three distinct clusters, all variables differed significantly among clusters (p<0.01). Cluster 1: Individuals (M4/F31, age 66.2 ± 5.09 years) exhibiting the lowest VAT (7.40 ± 2.33), high cognitive (ACE-R 93.45 ± 4.42), and physical performance across all motor tasks. Cluster 2: Individuals (M20/F28; age 65.85 ± 5.85 years) with high VAT (12.79 ± 3.97) and high cognitive function (ACE-R 92.67 ± 2.96) and high functional performance. Cluster 3: Individuals (M9/F47; age 65.85 ± 6.65 years) with VAT (9.93 ± 2.47), lower cognitive performance (ACE-R 85.50 ± 6.60) and diminished functional capacity, highlighting a parallel decline in cognitive and motor domains. Conclusions: Our observations indicate that while better functional lower-limb performance is linked to a higher cognitive capacity, the modulating influence of body composition and physical capacity is sex-dependent. Results of clustering analysis suggest that higher functional capacity could exert a protective effect against negative impacts of elevated metabolic risk. Acknowledgements: Supported by: ADDIT-CE HorizonEurope-WIDERA101087124; TEIDe ERA4Health NUTRIBRAIN-014; FWF Austria science fund KLI–1122; POO 09I01-03-V04-00077.