Irregular periods linked to increased risk of death before the age of 70, says BMJ
Women’s periods could act as a barometer for their general health, with irregular periods and long menstrual cycles associated with greater risk of dying before the age of 70, a study in the British Medical Journal suggests.
The menstrual cycle is the normal monthly hormonal cycle a woman’s body goes through during her reproductive years, counted from the first day of her period until the day before her next. On average, this lasts 28 days, but there is considerable variation between women, with 24 to 35 day cycles also considered normal.
Irregular cycles and ones longer than 40 days are also common and – although most women experience some disruption from time to time – longer-term they have been associated with a higher risk of diseases including ovarian cancer, heart disease, type 2 diabetes, and mental health problems. However, whether this translated into an increased risk of early death was unclear.
To investigate, Prof Jorge E Chavarro at Harvard TH Chan School of Public Health in Boston and colleagues used data from 79,505 healthy pre-menopausal women, collected as part of the “Nurses’ Health Study II”, which has been tracking the health of 116,429 female nurses in the United States since 1989.
After accounting for factors such as age, weight, lifestyle and family medical history, the team found that women who reported always having irregular menstrual cycles or cycles usually lasting longer than 40 days were at greater risk of premature death than women with very regular cycles, or ones that usually lasted 26 to 31 days. For women aged 29-46, those with irregular periods were 39% more likely to die prematurely than women reporting very regular cycles.
These associations were stronger for deaths related to cardiovascular disease and when long and irregular cycles were consistently present. They were also slightly stronger among women who smoked.
“This study is a real step forward in closing the data gap that exists in women’s health,” said Dr Jacqueline Maybin, a senior research fellow and consultant gynaecologist at the MRC Centre for Reproductive Health in Edinburgh. Even so, she stressed that irregular menstruation was a symptom and not a diagnosis.
It is possible that whatever is causing women to have long or irregular menstrual cycles is also responsible for their heightened risk of premature death. For instance, polycystic ovary syndrome (PCOS) is a common cause of irregular periods, and women with the condition are known to have an increased risk of diabetes, high blood pressure and cancer of the womb.
However, Chavarro suggested this was not the whole story: “I would say that while PCOS is part of why we are seeing this relation, it is only the extreme of a continuum of how the production of ovarian hormones is controlled.” He stressed that women should speak to their doctor if they have any concerns about their menstrual cycles.
“The important point illustrated by this study is that menstrual regularity and reproductive health provides a window into overall long term health, and measures to improve the health and wellbeing of young women with an irregular menstrual cycle may also enhance lifelong health,” adds Prof Adam Balen, Royal College of Obstetricians and Gynaecologists spokesperson on reproductive medicine.
“Therefore young women with irregular periods need a thorough assessment not only of their hormones and metabolism but also of their lifestyle so that they can be advised about steps that they can take which might enhance their overall health.”
