Correlation between the total volume, transitional zone volume of the prostate, transitional prostate zone index and lower urinary tract symptoms (LUTS)
OBJECTIVE To describe lower urinary tract symptoms, prostate volume and peak urinary flow rate, and investigate the relationships among urological variables in a community sample of Norwegian men. MATERIALS AND METHODS A cross-sectional study of 611 men, aged 55-70 years, who underwent a clinical urological examination including uroflowmetry, residual urine measurement, and transrectal ultrasonography of the prostate. All the men completed a questionnaire which included the International Prostate Symptom Score (IPSS). RESULTS Severe symptoms were reported by 5%, while 23.6% reported moderate symptoms, and the overall median IPSS was 4 (q1 = 25th percentile, 1; q3 = 75th percentile, 9). The median peak flow rate was 15 ml/s (q1 = 11; q2 = 22) while median prostate volume was 30 cm(3) (q1 = 23; q3 = 38), with little variation evident across the narrow age range of 55-70 years. A positive modest correlation (r = 0.176) was found between IPSS and prostate volume, and a negative correlation between IPSS and peak flow rate (r = -0.278). There was a modest correlation between body mass index (BMI) and prostate size, but no significant correlation between BMI and IPSS. CONCLUSION In this population-based study, moderate lower urinary tract symptoms were reported by 24% and severe symptoms by 5% of community men. The distribution of lower urinary tract symptoms, prostate volume and peak urinary flow rate in Norwegian men is comparable to that described in similar studies conducted in Spain, Holland and USA.