Evaluation of blood pressure in vasectomized and nonvasectomized men

We assessed the effect of vasectomy on blood pressure by collecting cross-sectional data on the systolic and diastolic blood pressure of 946 male volunteer blood donors; of these, 30% were vasectomized. We used analysis of multiple covariance to correct both pressures for variation in age, weight, and height. Vasectomized and nonvasectomized men did not differ significantly in mean systolic or diastolic blood pressures. However, many of these men had been vasectomized for only a short period of time. We analysed the vasectomy subsample by multiple regression to determine whether blood pressures adjusted for age, body mass index, and height changed with time since vasectomy and found a slight, but non-significant, rise in the systolic pressure with square of time since vasectomy. The data are sufficiently strong to raise concern that data from a sample of men who have been vasectomized for longer periods of time would have shown a more dramatic increase.