Heart disease is not just a "male" problem. New research finds a link between a woman's reproductive period and her risk of heart failure.
Although generally seen as a "man's condition," heart disease is the number one cause of death among women as well. The CDC estimate that in 2013, 1 in every 4 female deaths were attributed to heart disease.
Previous research has investigated the link between women's reproductive history and the risk of cardiovascular disease (CVD). Some studies have shown an association between maternal age and various forms of CVD, from arrhythmia to heart failure.
During pregnancy, a woman's sex hormones - such as progesterone, estrogens, and cortisol - rise up to 100 times their normal levels. Researchers have therefore suggested that these hormones can affect her risk of developing heart disease, either directly or indirectly, through other pregnancy-related metabolic changes.
Other studies have indicated that women who have their menopause early might also be at an increased risk of heart disease. New research - published in the Journal of the American College of Cardiology - seems to further strengthen this link, as researchers find an association between early menopause onset and the risk of heart failure.
Early menopause, short reproductive span linked to heart failure
The team looked at 28,516 postmenopausal women who did not have CVD and were enrolled in the Women's Health Initiative. Participants were clinically followed for an average period of 13.1 years, during which time 5.2 percent of the women had heart failure and were admitted to the hospital.
The researchers investigated the link between the total number of live births, the mother's age at first pregnancy, as well as the total reproductive duration - that is, the time between the onset of menstruation to the onset of menopause.
Overall, a short reproductive period correlated with a higher risk of heart failure. The risk was linked to reaching menopause at an earlier age, and the connection was stronger in women who had natural - not surgical - menopause.
Dr. Nisha I. Parikh, assistant professor at the University of California-San Francisco School of Medicine and senior author of the study, comments on the results:
"Our finding that a shorter total reproductive duration was associated with a modestly increased risk of heart failure might be due to the increased coronary heart disease risk that accompanies early menopause. These findings warrant ongoing evaluation of the potential cardioprotective mechanisms of sex hormone exposure in women."
Additionally, the study found that women who never gave birth had a higher risk of diastolic heart failure. This type of heart failure occurs when the left ventricle of the heart becomes rigid and cannot relax properly anymore, which prevents the heart from receiving the blood it needs between beats.
The correlation did not seem to have anything to do with infertility, the authors report. Furthermore, having more children did not have any bearing on the risk of heart failure.
In an editorial comment published alongside the study, Dr. Nandita S. Scott, co-director of the Corrigan Women's Heart Health Program at Massachusetts General Hospital in Boston, writes:
"There also remain many unresolved questions including the mechanisms of estrogen's cardioprotective effect, making this truly a work in progress. Altogether, these findings raise interesting questions about the cardiometabolic effects of sex hormone exposure over a woman's lifetime and continue to raise important questions for future research."