Kannel and Levy,1 commenting on the Framingham findings, which showed that natural menopause, surgical menopause with simple hysterectomy, or surgical menopause with hysterectomy and oophorectomy were associated with similar increases in coronary heart disease (CHD), suggested that an intact uterus might have a role in the protection of premenopausal women. A plausible explanation of these findings might be related to the beneficial effect of iron depletion in menstruating women (ie, the iron hypothesis suggested by Sullivan2 in 1981).
Mascitelli L, Pezzetta F. Cardiovascular Protection in Premenopausal Women. Arch Intern Med. 2005;165(1):120. doi:10.1001/archinte.165.1.120-a