Some evidence does suggest an association between irregular menstrual cycles – particularly longer ones where periods occur 32 to 39 days or more apart – may put women at risk of earlier death. This news came from an investigation that included 93,775 women participating in the long-running Nurses’ Health Study II who were followed for 22 years by researchers from Harvard T.H. Chan School of Public Health and China’s Tongji Medical College. None of the women had a history of heart or blood vessel disease, cancer or diabetes when they joined the study. All were asked to describe the usual length and regularity of their menstrual cycles when they were between the ages of 14 to 17, 18 to 22, and 28 to 48. Over the course of the study 1,679 women died, including 828 from cancer and 166 from cardiovascular disease.
The researchers reported that women whose cycles spanned 32 to 39 days or more than 40 days were at greater risk of early death than women whose usual cycles were in the normal range of 26 to 31 days. They also found that women whose cycles were always irregular between the ages of 14 and 17 and 18 to 22 were 21 percent and 34 percent more likely to die from any cause than women of the same age whose cycles were of normal length. The same was true of women age 28 to 48 whose cycles were irregular. The investigators used statistical methods to determine links between the characteristics of the women’s menstrual cycles and deaths and accounted for such variable factors as body mass index, race and ethnicity, physical activity and other aspects of lifestyle.
Women in particular should be aware that irregular menstrual cycles may be associated with serious health problems, including uncontrolled diabetes and polycystic ovary syndrome (PCOS) as well as stress and thyroid conditions. Obesity also correlates with irregular menstrual cycles as does losing a lot of weight. If your periods are irregular, you should first determine whether or not you’re affected by any of the medical problems that could be related. And be aware that irregular periods usually aren’t cause for concern during puberty or as menopause approaches. If you’re uncertain about the regularity of your periods, you can get an app for your phone to track your monthly cycle and identify any changes that occur.
The study findings have not yet been published in a peer reviewed medical journal but were presented in October (2019) at the annual conference of the American Society for Reproductive Medicine.
Andrew Weil, M.D.
Yixin Wang et al, “Menstrual Cycle Regularity and Length and Risk of Mortality: A Prospective Cohort Study” presented October 16, 2019 at the American Society for Reproductive Medicine, Philadelphia, PA