ICI‐RS 2019 nocturia think tank: How can experimental science guide us in understanding the pathophysiology of nocturia?

Abstract

Introduction The following is a report on the proceedings of the 2019 International Consultation on Incontinence‐Research Society nocturia think tank (NTT). Objectives The objectives of the 2019 NTT were as follows: (a) to evaluate the role of urothelium in the pathophysiology of nocturia; (b) to determine whether nocturia is a circadian disorder; (c) to discuss the role of melatonin in nocturia; (d) to consider ambulatory urodynamic monitoring in evaluating patients with nocturia; (e) to explore studies of water handling in human compartments utilizing heavy water; and (f) to explore whether basic science is the key to understanding the treatment options for diminished bladder capacity in patients with nocturia. Methods A compendium of discussions of the role of experimental science in understanding the pathophysiology of nocturia is described herein. Results and Conclusions Translational science will play an increasing role in understanding the pathophysiology of nocturia, which may result in improved treatment strategies.

Associations between nighttime and daytime maximum voided volumes: Relevance for nocturia?

“…Posture appears an unlikely explanation, as recumbent position attenuates common genitourinary abnormalities, such as detrusor overactivity and diminished leak‐point pressure in patients with stress‐related urinary incontinence 10,11 . However, new developments in understanding not only the chronobiology associated with urine production but also the impact of circadian rhythmicity on bladder function may bear greater relevance here 12 . The in vitro demonstration that an isolated bladder preparation may show circadian rhythmicity with spontaneous phasic activity likely during portions of the circadian day corresponding to the customary sleep period in humans implicates potassium‐channel, urothelial afferent stimulation as a possible contributing factor for voiding episodes during the night 13 .…”

“…Conversely, however, medications designed to treat prostatic obstruction or overactive bladder syndrome have not been found to demonstrate a clinically significant effect on voided volumes 12 . Accordingly, it is clinically important that future research be directed toward understanding causes and treatment of low nocturnal bladder capacity in patients with normal daytime capacity, which is now increasingly feasible with ambulatory urodynamic monitoring 12 …”

“…16 Conversely, however, medications designed to treat prostatic obstruction or overactive bladder syndrome have not been found to demonstrate a clinically significant effect on voided volumes. 12 Accordingly, it is clinically important that future research be directed toward understanding causes and treatment of low nocturnal bladder capacity in patients with normal daytime capacity, which is now increasingly feasible with ambulatory urodynamic monitoring. 12 The fact that the majority of nocturia patients with small FBC actually have 24-hour diminished FBC is of direct relevance to the use of nocturnal-only voiding diaries as a rational alternative for follow-up evaluation in patients with nocturia due to global small bladder capacity.…”

“…12 Accordingly, it is clinically important that future research be directed toward understanding causes and treatment of low nocturnal bladder capacity in patients with normal daytime capacity, which is now increasingly feasible with ambulatory urodynamic monitoring. 12 The fact that the majority of nocturia patients with small FBC actually have 24-hour diminished FBC is of direct relevance to the use of nocturnal-only voiding diaries as a rational alternative for follow-up evaluation in patients with nocturia due to global small bladder capacity. As the crux of a comprehensive clinical assessment, the utility of voiding diaries is recognized by current ICS consensus guidelines pertaining to the evaluation of nocturia.…”

“…Notably, antidiuretic replacement therapy, which primarily acts to reduce nocturnal urine production, has even been found effective in patients with a diminished nocturnal FBC (relative to their own 24‐hour FBC), 15 and may also help enable patients to void closer to their own 24‐hour FBC during the hours of intended sleep 16 . Conversely, however, medications designed to treat prostatic obstruction or overactive bladder syndrome have not been found to demonstrate a clinically significant effect on voided volumes 12 . Accordingly, it is clinically important that future research be directed toward understanding causes and treatment of low nocturnal bladder capacity in patients with normal daytime capacity, which is now increasingly feasible with ambulatory urodynamic monitoring 12 …”