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Etiology

Vasectomy was associated with lower mortality

ACP J Club. 1992 Sept-Oct;117:56. doi:10.7326/ACPJC-1992-117-2-056


Source Citation

Giovannucci E, Tosteson TD, Speizer FE, Vessey MP, Colditz GA. A long-term study of mortality in men who have undergone vasectomy. N Engl J Med. 1992 May 21;326:1392-8.


Abstract

Objective

To investigate the relation between vasectomy and death from cardiovascular disease, cancer, and all causes.

Design

Cohort analytic study of data obtained between 1976 and 1989.

Setting

Population study of the husbands of women in the Nurses' Health Study.

Participants

Of 121 700 married women aged 30 to 55 years in 1972, 14 607 who returned questionnaires in 1988 had reported in 1976 or 1978 that their husbands had had a vasectomy. These men were matched by the age of their spouse to a random sample of nurses' husbands for whom no vasectomy was reported by 1978. After eliminating women who were no longer married in 1976 or who did not return a 1989 questionnaire, 13 124 eligible men with vasectomies (90%) and 12 392 without (86%) were included.

Assessment of risk factors

The September 1989 questionnaire inquired about husband's age (mean, 42 y) and date of vasectomy; history of heart disease (5%) or cancer (2%); and, as of 1976, history of hypertension (16%), diabetes mellitus (3%), or raised cholesterol levels (12%), and height and weight (mean body-mass index, 26), smoking (nonsmokers, 63%), drinking habits (nondrinkers, 20%), and educational level (college educated, 54%).

Main outcome measures

All-cause, cardiovascular, and cancer mortality after 1975; fatal and nonfatal coronary heart disease. Causes of death were obtained from questionnaires and checked by death certificates. Masked medical and autopsy records were reviewed for > 50% of deaths.

Main results

487 men who had had a vasectomy and who were free of cancer in 1976 died (193 of cardiovascular disease and 173 of cancer) compared with 565 deaths (253 cardiovascular and 168 cancer) among men with no vasectomy (relative risk [RR] favoring vasectomy 0.85, 95% CI 0.76 to 0.96). Accounting for this was a reduced RR for death from cardiovascular causes for men with a vasectomy (0.76, CI 0.63 to 0.92) but not for cancer death (RR 1.01, CI 0.82 to 1.25). RRs for death were unchanged by adjustment for all risk factors. Longer duration since vasectomy did not significantly affect all-cause or cardiovascular mortality (adjusted RR for ≥ 20 y 1.11 [CI 0.92 to 1.33] and 0.85 [CI 0.63 to 1.16], respectively) but was associated with a greater risk for death from cancer (RR 1.44, CI 1.07 to 1.92). The rate of fatal and nonfatal coronary heart disease was not affected by vasectomy (RR 0.97, CI 0.87 to 1.09).

Conclusion

Vasectomy was associated with lower mortality among the husbands of American nurses.

Sources of funding: National Institutes of Health and American Cancer Society.

Address for article reprint: Dr. E. Giovannucci, Channing Laboratory, 180 Longwood Avenue, Boston, MA 02115, USA.


Commentary

Vasectomy does not increase mortality over a 20-year period. That is the main message of this superb epidemiologic study of mortality and morbidity. The attractive features of this study are the large number of participants and the long duration of follow-up that included a sizable group of men followed for > 20 years.

2 recent case-control studies had suggested an increased relative risk for prostate cancer (1, 2), although the increased risk in 1 study was only found in men with vasectomy done > 20 years earlier (2). This increased risk was not confirmed by Giovannucci and colleagues or by 2 long-term cohort studies (3, 4). The first study followed 10 600 matched pairs of men from 4 American cities for an average of 7.9 years, of which 2300 pairs were followed > 10 years. The second, from Kaiser Permanente, followed 5200 men, each matched with 3 controls for an average of 6.8 years. Neither study found any increased risk for prostate cancer after vasectomy in the short or long term.

Most human studies have shown decreased risk for coronary heart disease within the first 10 years after vasectomy, probably because healthier persons may be more likely to choose vasectomy. The power of the study by Giovannucci and colleagues is sufficient to extend the duration of no increase in risk for coronary and cardiovascular disease to > 20 years. A large proportion of American men choose to have vasectomies, as high as 25% in some groups by age 40 to 60. Except for increased orchitis or epididymitis within the first year (3), the cumulative evidence suggests that this method of avoiding unwanted pregnancies is medically harmless for up to 20 years and probably longer.

Donald Smith, MD
The Mount Sinai HospitalNew York, New York, USA

Donald Smith, MD
The Mount Sinai Hospital
New York, New York, USA


References

1. Rosenberg L, Palmer JR, Zauber AG, et al. Am J Epidemiol. 1990;132:1051-5.

2. Mettlin C, Natarajan N, Huben R. Am J Epidemiol. 1990;132:1056-61.

3. Massey FJ Jr, Bernstein GS, O'Fallon WM, et al. JAMA. 1984;252:1023-9.

4. Sidney S, Quesenberry CP Jr, Sadler MC, et al. Cancer Causes Control. 1991;2:113-6.