Invited Commentary: Sex and Race Differences in Diabetes and Cardiovascular Disease-Achieving the Promise of Sex and Race Subgroup Analyses in Epidemiologic Research.

Diabetes confers a higher risk of cardiovascular disease on women than on men. The reasons for these sex differences, such as poorer cardiovascular risk factor profiles, have received considerable attention. However, a recent report on sex × diabetes interactions on cardiovascular disease identified that few if any prior studies have confirmed these sex differences in black individuals, despite known diabetes-related disparities. In this issue of the Journal, George et al. (Am J Epidemiol. 2018;187(3):403-410.) found marginally significant multiplicative sex × diabetes interactions in black but not white study participants after adjustments for traditional and behavioral risk factors, competing risk, and change in diabetes status over time. This study is notable for its attempt to fill an important literature gap, and it elegantly addressed multiple statistical considerations in assessing sex × diabetes interactions according to race strata. The findings also highlighted several important considerations for conducting race and sex subgroup analyses.