Midlife surgical menopause not associated with increased cardiovascular risk when compared to natural menopause

Hysterectomy with or without oophorectomy in midlife was not associated with increased risk for cardiovascular disease (CVD) in a new study.

Researchers used data from the Study of Women's Health across the Nation (SWAN), a multisite, community-based prospective study, to compare changes in CVD risk factors up to and after natural menopause and up to and after hysterectomy with and without oophorectomy. At baseline, women included in the study had an intact uterus and at least one ovary, were 42 to 52 years of age, were not pregnant, were not using reproductive hormones, and had had at least one menstrual cycle in the preceding three months. Data for the current analysis were collected between 1996 and 2008.

At annual follow-up visits for 11 years, researchers measured sociodemographic characteristics, menopausal status, surgeries, BMI, medication use, lifestyle factors, lipid levels, blood pressure, insulin resistance, and hemostatic and inflammatory variables. Annual changes in CVD risk factors before and after the final menstrual period or surgery were compared. The study results were published online May 15 by the Journal of the American College of Cardiology.

A total of 3,302 premenopausal women were included in SWAN. By 2008, 1,769 had reached natural menopause, 77 had had a hysterectomy with ovarian conservation, and 106 had had a hysterectomy with bilateral oophorectomy. Multivariable analysis found that changes in cholesterol, apolipoprotein B, insulin resistance (as estimated by the Homeostasis Model of Assessment–Insulin Resistance), systolic blood pressure, plasminogen activatory inhibitor-1, and factor VIIc were similar for women with natural and surgical menopause over time.

Changes in other cardiovascular risk factors, including triglycerides, tissue plasminogen activator and apolipoprotein A, did differ with hysterectomy plus ovarian conservation compared with natural menopause. These risk factor changes conferred a protective cardiovascular effect for women post hysterectomy with ovarian conservation. Women who underwent hysterectomy with bilateral oophorectomy had larger increases in C-reactive protein beforehand compared with women before natural menopause, but this difference resolved after surgical and natural menopause occurred.

The authors noted that they could not evaluate the effect of age at surgery or the effect of surgery on clinical events and that the study sample was not representative of the general population, among other limitations. However, they concluded that based on their results, women in their 40s and 50s who had surgical menopause were not at greater cardiovascular risk than women who had natural menopause. “These results should provide reassurance to women and their clinicians that hysterectomy with or without ovarian conservation in mid-life is not likely to substantially accelerate women's CVD risk,” they wrote.