Abstract P178: The Association Between Multiparity And Endogenous Sex Hormone Levels In The Multi-ethnic Study Of Atherosclerosis (mesa)

Abstract

Introduction: Parity is a risk factor for adverse cardiovascular events in women compared to nulliparity. A more androgenic sex hormone profile, with increased testosterone to estrogen ratio, is associated with worse cardiovascular disease (CVD) outcomes in women and may be one mechanism that links a history of multiparity with future increased CVD risk. Given this, we investigated the relationship between parity and sex hormone levels. Methods: We studied 3,003 female MESA participants (ages 45-84 years and free of CVD) with complete data on parity and endogenous sex hormone levels at the baseline visit (2000 - 2002). Parity (number of live births) was categorized as 0 (reference), 1-2, 3-4, or ≥5. Progressively adjusted linear regression models were used to evaluate the association of parity categories with log-transformed levels of testosterone (T), estradiol (E2), sex-hormone binding globulin (SHBG), dehydroepiandrosterone (DHEA), and testosterone to estradiol (T/E2) ratio. Results: Mean (SD) age at the baseline MESA visit was 65 (9) years. Median sex hormone levels by parity group are shown in the Table . There were no significant associations of parity with E2, DHEA, and SHBG levels in multivariable-adjusted models. Compared to nulliparity, women with 1-2 and 3-4 live births had higher testosterone levels even after adjustment for CVD risk factors, but this was not significant for ≥5 live births. On the other hand, grand multiparity (≥5 live births) was associated with a higher T/E2 ratio compared to nulliparity, even after full covariate adjustment including demographics, lifestyle factors, CVD risk factors and medications. Conclusions: In a multiethnic US cohort of women, a history of grand multiparity is associated with a more androgenic sex hormone profile defined by higher T/E2 ratio at middle to older ages. The clinical significance of this is uncertain. Further longitudinal studies evaluating whether sex hormones influence the relationship between multiparity and CVD are warranted.