Due to previous animal research suggesting accelerated atherosclerosis following vasectomy, we examined whether vasectomy increases the risk of subsequent cardiovascular disease (CVD), including myocardial infarction (MI), angina pectoris, coronary revascularization, and stroke, in the US Physicians' Health Study. Of 22,071 US male physicians participating in the study, aged 40 to 84 years at entry and free from cardiovascular disease and cancer, 21,028 reported on the 60-month questionnaire whether they had undergone vasectomy prior to randomization. Of the 4546 physicians with vasectomy, 1159 had undergone the procedure at least 15 years before entry. During 258,892 person-years of follow-up, we documented 773 cases of MI (719 nonfatal and 54 fatal), 1907 cases of angina pectoris or coronary revascularization, and 604 confirmed cases of ischemic or hemorrhagic stroke (566 nonfatal and 38 fatal). When compared to men without prior vasectomy, the multivariate relative risk (RR) of total MI adjusted for age and other coronary risk factors was 0.94 (95% confidence interval [CI], 0.77-1.14) among men with vasectomy. Risk estimates for fatal and nonfatal events did not appreciably differ from each other. For angina or coronary revascularization or both, the multivariate relative risk was 0.99 (0.88-1.12) and for total stroke the RR was 0.95 (0.75-1.21). For men who had undergone vasectomy 15 or more years previously, the multivariate relative risks were 0.98 (0.73-1.32) for total MI, 1.17 (0.87-1.57) for total stroke, and 1.12 (0.94-1.35) for angina/revascularization. These results provide reassuring evidence that vasectomy does not materially increase the risk of subsequent cardiovascular disease, even 15 or more years following the procedure.
PIP: This paper examines the effects of vasectomy on cardiovascular health of 22,071 US male physicians, aged 40-84 years, free from cardiovascular disease (CVD) and cancer at entry to the US Physicians' Health Study. A total of 1159 out of 44,545 physicians had their vasectomy at least 15 years before entry. Results showed that during 258,892 person-years of follow-up, there were 773 cases of myocardial infarction (MI), 719 nonfatal and 54 fatal; 1907 cases of angina pectoris or coronary revascularization; and 604 cases of ischemic or hemorrhagic stroke, 566 nonfatal and 38 fatal. The multivariate relative risk (RR) of MI cases adjusted for age and other coronary risk factors was 0.94 among men with vasectomy as compared to those without prior vasectomy. For both angina and coronary revascularization, the multivariate RR was 0.99; for stroke, the RR was 0.95. The multivariate RR for men who had undergone the procedure 15 or more years previously was 0.98 (0.73-1.32) for total MI, 1.17 (0.87-1.57) for total stroke, and 1.12 (0.94-1.35) for angina pectoris/revascularization. With these results, it was evident that vasectomy does not increase the risk of subsequent CVD, even 15 or more years after the procedure.