The International Prostate Symptom score in both sexes: a urodynamics-based comparison

The aim of our study was to determine the urodynamic basis for the observation that aging women report comparable benign prostatic hyperplasia (BPH) symptom scores as age-matched men. Sixty-seven women (mean age, 60.4 +/- 1.5 years; mean +/- standard error of the mean) and 70 age-matched men (mean age, 63.7 +/- 0.9 years; P > 0.05) entered this prospective study. Men were referred for the diagnostic workup of lower urinary tract symptoms (LUTS) due to BPH and women predominantly for urinary incontinence. All patients completed the International Prostate Symptom score (IPSS) with quality-of-life assessment and underwent a detailed clinical and urodynamic evaluation including a multichannel pressure-flow study. Results of the IPSS, quality-of-life assessment, and irritative and obstructive component of the IPSS were correlated with urodynamic findings and the respective data were compared in both sexes. The mean IPSS was 15.7 for men and 13.0 for women (P = 0.02), quality-of-life score was higher in women (4.2 vs. 3.4; P = 0.0008). The irritative score was significantly higher in women (8.7 vs. 6.8; P = 0.003). Incidence of detrusor instability (DI), however, was higher in men (women, 38.1%; men, 48.6%; P = 0.015) and bladder capacity was higher in women (425 vs. 333 ml; P = 0.0001). There was no correlation between incidence and degree of DI with the irritative score in both sexes. The obstructive score was significantly higher in men (8.8 vs. 4.4; P = 0.0001). Ninety-one percent (64/70) of men had urodynamically documented bladder outlet obstruction (BOO), whereas this was the case in only 9% (6/67) of women. In parallel to the irritative score, we could not identify a correlation between the degree of urodynamically proven BOO and the obstructive score in both sexes. This urodynamics-based comparison fails to give an explanation for the observation that aging women report similar BPH scores as men. These data suggest that other mechanisms, such as changes in diurnal urine production, structural alterations of the aging detrusor, endocrine disturbances affecting lower urinary tract function, and subtle urodynamic changes are responsible.