The association of thigh myosteatosis with lower cognitive function in older cancer survivors.

INTRODUCTION Cancer is associated with accelerated aging, including changes in muscle composition and cognition. However, the relationship between myosteatosis and cognitive function has not been investigated in older cancer survivors. This study evaluated the association between myosteatosis and cognitive function in this population. METHODS The sample included 75 cancer survivors (age 76-85; 65% men; 31% Black; 41% prostate cancer; 21% breast cancer) from the Health ABC study who developed cancer within the first five years, completed CT imaging at Year 6, and cognitive testing at Year 10. Thigh intermuscular fat area (myosteatosis) was measured by CT at Year 6. Cognitive function was assessed using the Digit Symbol Substitution Test (DSST) and Modified Mini-Mental Status Exam (3MS) at Years 5 and 10. Multivariable models adjusted for demographics, education, cognitive function, and thigh muscle area at Year 5. Sensitivity analyses adjusted for leg strength, race, dementia risk factors, BMI, abdominal visceral fat, and thigh subcutaneous fat. LASSO regression identified key predictors of DSST and 3MS scores. RESULTS Greater thigh myosteatosis at Year 6 was associated with lower DSST (B =  - 0.212, p < 0.05) and 3MS (B =  - 0.145, p < 0.05) scores at Year 10. Associations remained significant after adjustment for strength, dementia risk, and adiposity. LASSO identified race, education, Year 5 cognition, and myosteatosis as key predictors for DSST as well as thigh muscle area and physical activity for 3MS. DISCUSSION Thigh myosteatosis is independently associated with lower cognitive performance in older cancer survivors and may represent a rehabilitation target to improve cognitive outcomes.