Yi-Xin Wang, research fellow in the Department of Nutrition at Harvard T.H. Chan School of Public Health, was first author of the study, which was published in JAMA Network Open on October 25. “Our results suggest that menstrual cycle dysfunction may be a useful marker for identifying women who are more likely to develop CVD events later in life,” wrote Wang and colleagues in the study.
The researchers analyzed the reported menstrual cycle characteristics of more than 80,000 women who took part in the Nurses’ Health Study II between 1993 and 2017. They found that women with irregular cycles or no periods had between 15% and 40% higher incidence of CVD—including coronary heart disease, myocardial infarction, coronary revascularization, and stroke—depending on age.
In addition, women who reported a menstrual cycle length of more than 40 days, or a cycle too irregular to estimate, had between 30% and 44% higher incidence of CVD. The increased risk was far beyond that explained by other factors such as high blood pressure or diabetes.
The study authors noted that the most common cause for irregular menstrual cycles is polycystic ovary syndrome (PCOS), a hormonal disorder that can affect women during reproductive years. PCOS, which affects approximately 90% of women with irregular menstrual cycles, has also been associated in studies with increased risk of CVD. Therefore, the researchers wrote, the increased risk is likely attributable to underlying PCOS.
Other authors of the study included Harvard Chan School’s Jennifer Stuart, Janet Rich-Edwards, Stacey Missmer, and Jorge Chavarro, as well as researchers from Brigham and Women’s Hospital, Harvard Medical School, and other institutions.
Read a Healio article: Irregular, long menstrual cycles may be indicative of future CVD