Prevalence of benign prostatic hyperplasia in a population-based study in Iranian men 40 years old or older.

Epidemiology of benign prostatic hyperplasia (BPH) is incompletely understood. The following study was done to estimate the prevalence of BPH according to obstructive and irritative symptoms of prostate obstruction determined by uroflowmetry and prostate size. In a cross-sectional study a total of 8,466 men aged 40 or older were interviewed by 74 general practitioners and answered the International Prostate Symptom Score (I-PSS) questionnaire. The subjects were randomly identified from 30 counties of Iran. They were invited to have a digital rectal examination (DRE), serum total prostate-specific antigen (tPSA) assay, abdominal ultrasonography to measure prostate size and measurement of maximum urinary flow rate (Qmax). Data on medical history, toxic habits, and current use of medications were obtained. Of the men interviewed, the prevalence of BPH, defined as I-PSS greater than 7, maximum flow less than 15 ml/s and prostate size greater than 30 gm, was 23.8%. The prevalence increased with age, from 1.2% in men 40-49 to 36% in those >70 years (tested for trend, P = 0.001). A positive association was found between BPH and body mass index (BMI) (P = 0.04), height (P = 0.03), diabetes mellitus (P = 0.04), increased total energy intake (P = 0.02), age-adjusted levels of total PSA (P = 0.02), heart disease (P = 0.03), and marital status (P = 0.01). The prevalence of BPH is relatively high in Iran. The provided bothersome due to BPH did not correlate to symptom severity and should be considered independently in clinical decision-making.