Normal voiding patterns and determinants of increased diurnal and nocturnal voiding frequency in elderly men

Purpose: We determined the normal value of diurnal and nocturnal voiding fr equency, and its determinants in a population based sample of elderly men. Materials and Methods: We collected data on 1,688 men 50 to 78 years old re cruited from the population of Krimpen, The Netherlands. Measurements consi sted of self-administered questionnaires, including the International Prost ate Symptom Score (I-PSS), a 3-day frequency-volume chart, transrectal pros tatic ultrasound, uroflowmetry and post-void residual urine volume measurem ent. Results: Diurnal voiding frequency is independent of age and more frequent in men with benign prostatic hyperplasia (BPH). Nocturia 2 or more times is present in 30% of men 50 to 54 and in 60% of those 70 to 78 years old, whi le nocturia 3 or more times is present in 4% and 20%, respectively. In addi tion, nocturia is strongly associated with BPH and nocturnal polyuria but a pparently not with cardiovascular symptoms, hypertension or diabetes mellit us. We noted poor agreement of the responses on the frequency-volume charts and the I-PSS question on nocturia. Using the I-PSS leads to a higher prev alence of nocturia. Conclusions: Diurnal frequency is independent of age (median 5 voids, inter quartile range 4 to 6) but higher in men with BPH. Nocturia increases with advancing age and is more frequent in men with nocturnal polyuria. BPH is a n independent risk factor for nocturia and increased diurnal voiding freque ncy. In those with nocturia there is a great difference in subjective sympt oms and objective data, indicating that the weight of the I-PSS question on nocturia for making treatment decisions should be reconsidered.