Objective:

Background:

Endometriosis is an inflammatory chronic gynecologic condition that affects approximately 10% of reproductive aged women. Previous research suggests that endometriosis increases stroke risk, but the role of medications known to prevent stroke in modifying this risk is uncertain.

Design/Methods:

We retrospectively analyzed data from the California Teachers Study, a large prospective cohort of female teachers followed continuously since 1995, excluding those with prior stroke or heart attack. This analyses’ exposure was self-reported history of endometriosis, and the outcome was hospitalization for any stroke (ischemic stroke, intracerebral and subarachnoid hemorrhage). Study covariates were self-reported use of aspirin and statin, race-ethnicity, hysterectomy, and vascular risk factors: hypertension, diabetes mellitus, obesity, migraine, current or prior tobacco use, malignancy, and oral contraceptive use. We used Cox proportional hazards models to calculate hazard ratios (HR) and 95% confidence intervals (CI) for stroke by age among women with and without history of endometriosis after adjustment for demographics and vascular risk factors. We examined association of aspirin and statin use with stroke among women with endometriosis.

Results:

Of 121,993 women, 13,938 (11.4%) reported a history of endometriosis. Women with endometriosis had slightly higher rates of vascular risk factors than women without endometriosis. Adjusted risk of stroke in the endometriosis group was higher than in the non-endometriosis group (HR 1.20, CI 1.09-1.28). Stroke occurred at a younger age among women with endometriosis (77.9 vs 80.2, p<0.01). Within the endometriosis group, stroke risk in users of aspirin (HR 0.80, CI 0.69-0.92) or statins (HR 0.74, CI 0.62-0.88) was lower than that of non-users.

Conclusions:

In a large cohort study, history of endometriosis was associated with increased stroke risk and, among women with endometriosis, aspirin and statin use decreased this risk.