Incident Impaired Cognitive Function in Sarcopenic Obesity: Data From the National Health and Aging Trends Survey

Objectives: The prevalence of obesity with sarcopenia is increasing in adults aged ≥65 years. This geriatric syndrome places individuals at risk for synergistic complications that leads to long-term functional decline. We ascertained the relationship between sarcopenic obesity and incident long-term impaired global cognitive function in a representative US population. Design: A longitudinal, secondary data set analysis using the National Health and Aging Trends Survey. Setting: Community-based older adults in the United States. Participants: Participants without baseline impaired cognitive function aged ≥65 years with grip strength and body mass index measures. Methods: Sarcopenia was defined using the Foundation for the National Institutes of Health Sarcopenia Project grip strength cut points (men <35.5 kg; women <20 kg), and obesity was defined using standard body mass index (BMI) categories. Impaired global cognition was identified as impairment in the Alzheimer's Disease-8 score or immediate/delayed recall, orientation, clock-draw test, date/person recall. Proportional hazard models ascertained the risk of impaired cognitive function over 8 years (referent = neither obesity or sarcopenia). Results: Of the 5822 participants (55.7% women), median age category was 75 to 80, and mean grip strength and BMI were 26.4 kg and 27.5 kg/m², respectively. Baseline prevalence of sarcopenic obesity was 12.9%, with an observed subset of 21.2% participants having impaired cognitive function at follow-up. Compared with those without sarcopenia or obesity, the risk of impaired cognitive function was no different in obesity alone [hazard ratio (HR) 0.98; 95% confidence interval (CI) 0.82–1.16]), but was significantly higher in sarcopenia (HR 1.60; 95% CI 1.42–1.80) and sarcopenic obesity (HR 1.20; 95% CI 1.03–1.40). There was no significant interaction term between sarcopenia and obesity. Conclusions: Both sarcopenia and sarcopenic obesity are associated with an increased long-term risk of impaired cognitive function in older adults.