Obesity and benign prostatic hyperplasia.

Abdominal obesity increases the estrogen-to-androgen ratio and may increase sympathetic nervous activity, both hypothesized to influence the development of benign prostatic hyperplasia and the severity of urinary obstructive symptoms. In 1986 and 1987, men aged 40-75 years who were participants in the Health Professionals Follow-up Study and who were without prior diagnosis of cancer or prostatectomy provided data on weight, height, and waist and hip circumferences. The men were followed for incidence of prostatectomy for benign prostatic hyperplasia up to January 1992. In addition, the frequency and severity of symptoms of urinary obstruction were assessed among respondents to a questionnaire in 1992. Among 25,892 men who provided complete information for both surgery and symptoms, 837 men had surgery for benign prostatic hyperplasia, and 2,581 of those without surgery reported frequent urinary symptoms. After adjustment for age, smoking, and body mass index, abdominal obesity was related to prostatectomy (odds ratio (OR) = 2.38, 95% confidence interval (CI) 1.42-3.99, for those with a waist circumference > or = 43 inches (109 cm) relative to those with a waist circumference < 35 inches (89 cm); p trend < 0.0001) and with frequent urinary symptoms among those without prostatectomy (OR = 2.00, 95% CI 1.47-2.72; p < 0.0001). Body mass index, hip circumference, and waist-to-hip ratio were not associated with benign prostatic hyperplasia independently of waist circumference. These results suggest that abdominal obesity in men may increase the frequency and severity of urinary obstructive symptoms and may increase the likelihood that such obese men will undergo a prostatectomy.