Prostate Specific Antigen Levels: Effect of Sexual Activity

Abstract

Background: To determine whether six lifestyle factors (dietary fat, smoking, sleep, alcohol consumption, physical, and sexual activities) are associated with non-prostate cancer-related, elevated prostate specific antigen (PSA) levels. Methods: PSA levels were measured on frozen serum that was collected at baseline (time T1, 1987–1989) and at follow-up (time T2, 1995–1996) in the Massachusetts Male Aging Study, a population-based random sample survey of 1709 men aged 39–70 years old. Men with a PSA level >4.0 ng/ml at time T2 were offered a biopsy. Excluding men who had ever had a diagnosis of prostate cancer (N = 82) left 892 men with both time T1 and time T2 PSA measurements. Lifestyle factors assessed at time T1 were used for the analysis. Results: Of 866 men who had a time T1 PSA 4.0 ng/ml at time T2. In logistic regression models predicting crossing the threshold of 4.0 ng/ml, sexual activity was a significant predictor, but other lifestyle factors were not. Relative to little or no sexual activity, the age-adjusted odds ratio for sex 1–3 times/month was 4.18 (95% confidence interval (CI) = 1.4–12.3), and for sex ≥4 times/month was 2.54 (95% CI = 0.9–6.9). Conclusions: Men who were more sexually active at time T1 were at higher risk of a falsely elevated PSA level >4.0 ng/ml at time T2. Although interim knowledge about lifestyle is lacking, this finding may reflect the effect of ejaculation on serum PSA. Other lifestyle factors had no effect on time T2 PSA levels.