Heart disease risk factors, diabetes, and prostatic cancer in an adult community.

The authors studied the association between heart disease and prostatic cancer in Rancho Bernardo, California, from August 1972 to June 1987. During a 14-year follow-up of 1,776 men aged 50-84 years, 100 cases of prostatic cancer were identified, of which 54 were incident. Systolic blood pressure, cigarette smoking, and plasma cholesterol levels in cases did not differ from those in noncases. After adjustment for age and on multivariate analysis, incident cases of prostatic cancer had a nonsignificantly higher frequency of reported heart disease at baseline. History of diabetes was inversely associated with total prostatic cancer (age-adjusted estimated relative risk = 0.2, 90% confidence interval: 0.0-0.8; multivariate-adjusted relative risk = 0.3, 90% confidence interval: 0.1-1.0). The association between heart disease and prostatic cancer is compatible with diagnostic detection bias. The inverse association between diabetes and prostatic cancer is compatible with a cancer-promoting role for endogenous testosterone, the level of which is lower in diabetics, or a risk-reducing effect of antidiabetic diet or drug therapy.