Parity History and Later Life Sex Hormone Levels in the Multi-Ethnic Study of Atherosclerosis (MESA)

Background: Multiparity is a risk factor for cardiovascular disease (CVD). A more androgenic sex hormone profile, with a higher testosterone (T)/estradiol (E2) ratio, is associated with worse CVD outcomes in women and might be one mechanism linking multiparity to increased CVD risk. We investigated the relationship between parity and sex hormones at mid-to-older age. Methods: We performed a cross-sectional analysis of 2979 women with data on parity and endogenous sex hormone levels from the Multi-Ethnic Study of Atherosclerosis (MESA), a community-based cohort. Parity and gravidity (our exposures) were categorized as 0 (reference), 1-2, 3-4, or ≥ 5. Our outcome measures were T, E2, sex hormone binding globulin, dehydroepiandrosterone, and T/E2 ratio. Progressively adjusted linear regression was used to evaluate the association of parity/gravidity with sex hormones. Results: In multivariable adjusted models, there were no significant associations of parity with E2, dehydroepiandrosterone, and sex hormone binding globulin. Compared with nulliparity, after adjustment for CVD risk factors, women with 1-2 and 3-4 live births had higher T, but this was not significant for grand multiparity (≥ 5 live births). However, grand multigravidity (≥ 5 pregnancies) was associated with 10% (95% confidence interval [CI], 1%-20%) higher T and 14% (95% CI, 1%-29%) higher T/E2, compared with null gravidity. Grand multiparity was associated with an 18% (95% CI, 4%-34%) higher T/E2 ratio compared with nulliparity, after adjustment for CVD risk factors. Conclusions: In this multiethnic cohort, women with grand multigravidity and grand multiparity had higher T/E2 levels, reflecting a more androgenic sex hormone profile. Longitudinal studies on sex hormones’ influence on the relationship between multiparity and CVD are warranted.