Nocturnal polyuria in women with overactive bladder symptoms and nocturia

This study was undertaken to determine the prevalence of nocturnal polyuria in women complaining of nocturia and overactive bladder (OAB) symptoms and to identify clinical and health characteristics associated with nocturnal polyuria.

Women presenting to a urogynecology clinic with complaints of nocturia and OAB symptoms were asked to participate. They completed a health characteristic summary, 3-day voiding diary, Nordic sleep questionnaire, urinary distress inventory (UDI), and a nocturia distress visual log (NDVL). The 24-hour urine production, nighttime urine volume, and maximum bladder capacity were calculated from the bladder diary. Nocturnal polyuria was defined as production of greater than 33% of the 24-hour urine volume during an 8-hour sleep period. A histogram was performed to analyze at what age the prevalence of nocturnal polyuria increased. Women were then divided by presence or absence of nocturnal polyuria and compared by the health and clinical characteristics.

Fifty-five women met the qualifications and participated in the study. Average age of the cohort was 65.8 +/- 13.5 years. The risk of nocturnal polyuria increased with age 65 years or older (prevalence for age 65-74 = 0.86 [0.62-1.00]) and with white race. On the basis of the mean population values for UDI, NDVL, sleepiness scores, and insomnia scores, all women were bothered by their nocturia. Median number of nighttime voids, 24-hour urine production, maximum bladder capacity, nocturnal index, UDI, NDVL, sleepiness scores, and insomnia scores did not differ, based on presence or absence of nocturnal polyuria.

Among women complaining of nocturia and overactive bladder symptoms, age 65 years or older and white race appear to be risk factors for nocturnal polyuria.