Sex-related differences in cognitive trajectories in older individuals with type 2 diabetes and overweight or obesity

Abstract

Introduction: It is unknown whether rates of cognitive decline differ between older women and men with type 2 diabetes (T2D) and overweight or obesity. Methods: Two to four cognitive assessments were obtained across up to 10 years from 2799 adults (mean age 68 years; 62% women) with T2D who had been enrolled in a clinical trial of weight loss intervention. Sex-related differences in means and rates of decline of cognitive scores were assessed. Results: Women outperformed men in verbal learning and processing speed (P < 0.001), but not executive function (P = 0.22). The rates of decline over time for women and men were similar (P ≥ 0.10); however women, but not men, with apolipoprotein E (APOE) ε4 alleles had steeper declines in verbal learning (P = 0.02) and processing speed (P = 0.007) than those without these alleles. Discussion: Cognitive advantages for women with T2D and overweight/obesity over men are preserved as they age; however, these are eroded by the APOE ε4 genotype.