The Etiology and Classification of Nocturia in Adults

Kim, Eun Tak; Lee, Sang Ik; Lee, Kyu Sung

Abstract

PURPOSE: Nocturia, from which the patients feel the most discomfort, is one of the frequently complained urologic symptoms combined with insomnia. Studying the etiology and classification of nocturia is not enough. In this study, we analyzed the voiding diary and urodynamic study to investigate the etiology of nocturia. We classified the type of nocturia based on the etiology.
MATERIALS AND METHODS
We reviewed the urodynamic study (UDS) as well as the three days voiding diary of 152 patients with nocturia. We classified nocturia into three groups based on the voiding diaries and the results of UDS: Pure nocturnal polyuria in which the voided urine volume during the hours of sleep is more than 35% of the 24-hours urine volume, detrusor overactivity defined as existing uninhibited contraction on filling cystometrogram, and mixed (nocturnal polyuria with detrusor overactivity). Polyuria (24-hours urine output >2,500cc) was classified separately.
RESULTS
The mean number of nocturia was 3.3 (3.1 for men, 3.4 for women). octurnal polyuria, detrusor overactivity and mixed were 50.0%, 7.9% and 17.1% respectively. Nocturnal polyuria was not related with detrusor overactivity, bladder outlet obstruction and impaired detrusor contractility, but significantly increased with age (p<0.01) and in men (p<0.05). Detrusor overactivity was not related to impaired detrusor contractility, but was significantly related to the bladder outlet obstruction (p<0.05) and increased with age (p<0.01) and in men (p<0.01). Seventeen (11.2%) had polyuria.
CONCLUSIONS
In 75% of nocturia patients, there were nocturnal polyuria, detrusor overactivity or mixed type and 11.2% of them had polyuria. Therefore we conclude that these three causes were the main etiology of nocturia, and nocturia could be classified and treated based on these results.