Sex differences in the progression of cerebral microbleeds in patients with concomitant cerebral small vessel disease

Background and purpose: Sex differences in cerebral microbleeds (CMBs) are not well-known. We aimed to assess the impact of sex on the progression of CMBs. Methods: The CHALLENGE (Comparison Study of Cilostazol and Aspirin on Changes in Volume of Cerebral Small Vessel Disease White Matter Changes) database was analyzed. Out of 256 subjects, 189 participants with a follow-up brain scan were included in the analysis. The linear mixed-effect model was used to compare the 2-year changes in the number of CMBs between men and women. Results: A total of 65 men and 124 women were analyzed. There were no significant differences in the prevalence (70.8 vs. 71.8%; P = 1.000) and the median [interquartile range (IQR)] number of total CMBs [1 (0–7) vs. 2 (0–7); P = 0.810] at baseline between men and women. The median (IQR) increase over 2 years in the number of CMBs was statistically higher in women than in men [1 (0–2) vs. 0 (0–1), P = 0.026]. The multivariate linear mixed-effects model showed that women had a significantly greater increase in the number of total, deep, and lobar CMBs compared to men after adjusting for age and the baseline number of CMBs [estimated log-transformed mean of difference between women and men: 0.040 (P = 0.028) for total CMBs, 0.037 (P = 0.047) for deep CMBs, and 0.047 (P = 0.009) for lobar CMBs]. Conclusion: The progression of CMB over 2 years was significantly greater in women than in men.