Association between estimated total skeletal muscle mass and cognitive function in older adults

The study aimed to evaluate the association between estimated total skeletal muscle mass (eTSMM) and cognitive function in adults aged ≥60 years. A total of 1336 participants from the National Health and Nutrition Examinations Survey (2011-2014) were categorized into low, middle, and high eTSMM groups based on Lee's equation. Cognitive performance was evaluated using the Consortium to Establish a Registry for Alzheimer's Disease-Word Learning (CERAD-WL) and -Delayed Recall (CERAD-DR), Animal Fluency (AF) test, and Digit Symbol Substitution Test (DSST). Compared with low and middle eTSMM groups, the high eTSMM group exhibited superior CERAD-WL, CERAD-DR, AF, and DSST test performance. Multivariable linear regression analysis revealed eTSMM was significantly associated with the DSST score (with the low eTSMM group as the reference, the beta coefficient [95 % confidence interval] in the high eTSMM group was 3.95 [1.18, 6.73], P = 0.005). The following stratified analysis demonstrated a persisted association in individuals aged 60-75 years, men, with a lower body mass index (<25 kg/m²), and hypertension, indicating monitoring eTSMM may help identify cognitive impairment in those populations.