Sex differences in cerebrovascular pathologies on FLAIR in cognitively unimpaired elderly
To examine sex differences in cerebrovascular pathologies (CVPs) as seen on fluid-attenuated inversion recovery (FLAIR) MRI and in cardiovascular and metabolic risk factors in a population-based cognitively unimpaired cohort and to examine whether sex is independently associated with FLAIR findings after accounting for differences in important midlife risk factors.Methods
We identified 1,301 cognitively normal participants (663 men and 638 women) enrolled in the Mayo Clinic Study of Aging (age ≥70 years) who had FLAIR MRI and ascertained total burden of white matter (WM) hyperintensities (WMH), subcortical infarctions, and cortical infarctions. We compared CVPs and midlife and late-life vascular risk factors between men and women. We fit regression models with each CVP as an outcome, treating age, sex, and midlife risk factors as predictors.Results
Women had significantly greater WMH volume relative to their WM volume compared to men (2.8% vs 2.4% of WM, p < 0.001), while men had a greater frequency of cortical infarctions compared to women (9% vs 4%, p < 0.001). Subcortical infarctions were equally common in men and women (20%). In regression modeling after adjustment for WM volume, the mean WMH volume difference between men and women was of the same magnitude as a 7-year difference in age. In contrast, men had 2.2-greater relative odds of having a cortical infarction compared to women. These sex differences persisted even after adjustment for midlife vascular risk factors.Conclusions
There were important sex differences in CVP findings on FLAIR in cognitively unimpaired elderly. Understanding these sex differences could aid in the development of sex-specific preventive strategies.