Presentation Authors: Thomas Monaghan*, Matthew Epstein, Kyle Michelson, Nicholas Suss, Viktor Flores, Zhan Wu, Brooklyn, NY, Donald Bliwise, Atlanta, GA, François Hervé, Karel Everaert, Ghent, Belgium, Jeffrey Weiss, Brooklyn, NY
Introduction: Nocturnal Polyuria (NP) in the absence of identifiable contributory comorbidities is known as the Nocturnal Polyuria Syndrome (NPS) and is thought to be due to blunted secretion of endogenous arginine vasopressin (AVP) during the course of sleep. This study aims to determine if patients with NPS have a uniform vs. phasic nocturnal diuresis rate by comparing early (before first nocturnal void) and late (after first nocturnal void) nocturnal diuresis rates.
Methods: A frequency-volume chart (FVC) database of 773 entries from 440 men treated at a Veterans Affairs Urology clinic was analyzed. FVCs completed by patients â‰¥18 years with â‰¥2 nocturnal voids were included. Only the first FVC was used for patients with multiple diaries. Patients with alternate causes of NP (diuretic use, sleep apnea, heart failure, edema, kidney disease, and diabetes insipidus) were excluded. Patients were divided into two cohorts by NP status using two definitions for NP: nocturnal urine production (NUP) >90 mL/h and nocturnal polyuria index (NPi) >0.33._x000D_
Standard FVC parameters were used to calculate an &[Prime]early nocturnal diuresis rate&[Prime] (ENDR; first nocturnal voided volume/duration of first uninterrupted sleep period), &[Prime]late nocturnal diuresis rate&[Prime] (LNDR; remaining nocturnal urine volume/remaining hours of sleep), and &[Prime]diurnal diuresis rate&[Prime] (DDR; daytime urine volume/hours awake) (Table 1a&1b). A Wilcoxon signed-rank test was used for significance.
Results: Within the NPS cohort, significant differences between ENDR and LNDR were observed for both NUP >90 mL/h (152 vs. 120 mL/h, p=0.02) and NPi >0.33 (120 vs. 91.2 mL/h, p=0.02) (Figure 1). Within the non-NPS cohort, no significant differences were seen between ENDR and LNDR at NUP â‰¤90 or NPi â‰¤0.33.
Conclusions: In NPS patients, there exists a unique skew in nocturnal urine production such that a disproportionately large amount of the nocturnal volume is produced in the early hours of sleep. This may provide the specific substrate for short-acting AVP replacement pharmacotherapy approved for use in patients with nocturia owing to NPS.