Association of obesity and diabetes in sex‐related differences in cognitive function: Findings from the Cocoa Supplement and Multivitamin Outcomes Study for the Mind (COSMOS‐Mind): Epidemiology / Risk and protective factors in MCI and dementia

Background: Type 2 diabetes and mid‐life obesity increase the risk for cognitive decline and cognitive impairment in men and women. Studies disagree, however, on whether the associations diabetes and obesity have with cognitive function vary by sex. Method: We analyzed data from the COSMOS clinical trial and its COSMOS‐Mind ancillary study of cocoa extract (including 600 mg/d cocoa flavanols) and a multivitamin to reduce risks for major cardiovascular events and total invasive cancer (COSMOS), and cognitive decline (COSMOS‐Mind). In COSMOS‐Mind we administered a standardized telephone‐based cognitive battery to assess episodic memory, executive function and global cognition in 2,262 adults, age>65 (mean=73) years, 58% women, 33% obese (body mass index >30 kg/m2), and 10% diabetes. Individuals with histories of myocardial infarction, stroke, or cancer (excluding non‐melanoma skin cancer) were excluded. Sex, obesity, and diabetes were based on self‐report. Multiple regression analyses were used to compare cross‐sectional associations between cognitive function and age for women and men grouped by obesity and diabetes, with adjustments for education and race/ethnicity. Result: Women averaged better scores than men for memory (mean+standard error difference=0.42+0.04 SDs), executive function (0.26+0.04 SDs), and global cognitive function (0.30+0.4 SDs), all p<0.001. These differences were evident for individuals both with and without obesity or diabetes (all two‐way interactions p>0.20). Obesity, compared with no obesity, was associated with less steep slopes with greater age among women in all domains (all p<0.04), with no differences seen in men for any domain. This held without and with adjustment for diabetes. For composite cognitive function, the slope of the association with greater age was ‐0.064+0.005 SD/year among women without obesity compared with ‐0.030+0.009 SD/year among those with obesity (p=0.001), and the differences between women and men with obesity increased with age. After adjustment for obesity, diabetes was not associated with steeper slopes with age for any domain in either sex. Conclusion: In the COSMOS‐Mind cohort of clinical trial volunteers, the difference in cognitive function between women and men with obesity increased with age. However, in these cross‐sectional analyses we cannot rule out potential biases related to self‐report or differential survival. [ABSTRACT FROM AUTHOR]