Several reproductive factors contributed to a higher risk of cardiovascular disease among women, including early periods and early menopause, researchers found.
A history of hysterectomy was also linked with increased risk of cardiovascular disease (CVD) and coronary heart disease, reported Sanne AE Peters, PhD, and Mark Woodward, PhD, both of the University of Oxford in England.
However, history of oophorectomy, as well as age at first birth, had either no associations or only minor inverse associations with increased risk for cardiovascular disease, the authors wrote in Heart.
They pointed to “increasing evidence” that in addition to traditional risk factors such as elevated blood pressure, smoking, and obesity, certain reproductive factors may be linked with later cardiovascular disease, though the evidence is “mixed and inconsistent.”
This cross-sectional analysis of UK Biobank data comprised 267,440 women and 215,088 men ages 40 to 69 without a history of cardiovascular disease. The authors found that during 7 years of follow-up, there were 9,054 cases of cardiovascular disease, 5,782 cases of coronary heart disease, and 3,489 cases of stroke. Women comprised about a third of cardiovascular disease cases, a little under 30% of coronary heart disease cases, and about 40% of stroke cases.
Examining demographic data for women, the mean age was 56, about half were from a higher socioeconomic bracket in the U.K., and 60% said they never smoked.
Results were mixed for certain reproductive factors and increased risk for cardiovascular disease. The mean age for menarche was 13 years, and women who had their first periods prior to age 12 had a higher risk of cardiovascular disease (adjusted HR 1.10, 95% CI 1.01-1.30) than women who had menarche at a later age. Similar increased risks were seen for coronary heart disease (adjusted HR 1.05, 95% CI 0.93-1.18) and stroke (adjusted HR 1.17, 95% CI 1.03-1.32).
Sixty-one percent of women in the study were postmenopausal, with a mean age at natural menopause of 50 years. But early menopause was also linked with increased risk of cardiovascular disease (adjusted HR 1.33, 95% CI 1.19-1.49), coronary heart disease (adjusted HR 1.29, 95% CI 1.10-1.51), and stroke (adjusted HR 1.42, 95% CI 1.21-1.66).
Likewise, history of hysterectomy was linked with an increased risk of cardiovascular disease (adjusted HR 1.12, 95% CI 1.03-1.22) and coronary heart disease (adjusted HR 1.20, 95% CI 1.07-1.34).
Eighty-five percent of women had been pregnant, and 44% of women had two children, while 42% of men had fathered two children. Compared with women and men without children, there was a significantly higher risk of coronary heart disease in women (adjusted HR 1.21, 95% CI 1.05-1.40). But because these risks were similar among men (adjusted HR 1.13, 95% CI 1.04-1.23), the authors concluded that “this is unlikely to be due to a biological cause.”
The authors suggested that, “More frequent cardiovascular screening would seem to be sensible among women who are early in their reproductive cycle, or who have a history of adverse reproductive events or a hysterectomy, as this might help to delay or prevent their onset of CVD.”
Peters and Woodward disclosed support from the U.K. government.