Researchers Melissa Wellons, MD, MHS; Dhananjay Vaidya, PhD, MPH; Pamela J. Schreiner, PhD; David M. Herrington, MD, MHS; Pamela Ouyang, MBBS analyzed a population-based cohort of 3,601 women as part of the Multi-ethnic Study of Atherosclerosis, excluding women who reported a pre-menopausal hysterectomy without a bilateral oophorectomy (because researchers were unable to determine age-at-menopause.
The final sample size was 2,509 women, all of whom were between the ages of 45 and 84, and were free of cardiovascular disease at a baseline exam between July 2000 and 2002.
The primary outcome measures were cardiovascular events including myocardial infarction, resuscitated cardiac arrest, definite angina, probable angina (if followed by revascularization), stroke, coronary heart disease death, stroke death, and any other atherosclerotic CVD death.
The researchers identified race/ethnicity, smoking, hypertension, diabetes, total cholesterol, HDL-C, and menopause as covariates, and used T-tests, chi-square tests, the Kaplan-Meier estimator, and the Cox proportional hazards model to analyze their data.
1) There was a two-fold increased risk of future CVD in multi-ethnic US post-menopausal women .
2) Early menopause is a potential marker of increased risk of future CVD events (5.9% of women with early menopause had heart events, compared to 2.6% without).
3) Clinicians should obtain age-at-menopause for use as part of a patient’s clinical profile.
4) Though the test of interaction did not reach statistical significance, bilateral oopherectomy conferred an increased risk of cardiovascular event.
Strengths and limitations
Researchers identified the large multi-ethnic population (987 White, 331 Chinese, 641 Black, 550 Hispanic); the seven years of follow up, and well-adjudicated CVD events as the study’s strengths. Its limitations, they said, stemmed form the fact that subjects self-reported their age-at-menopause that most women were more than 10 years from menopause at the time of study.
One audience member wanted to know more about the effects of oophorectomy on CVD risk. The authors had not examined that, however, they thought it an excellent question, and seemed to be interested in taking up the point for future consideration.
So if anyone is interested in investigating the effects of bi- and unilateral oophorectomy on CVD risk compared to no surgery, get in touch with them; it could be a great partnership.