1012 Urologic Features Related to the First Uninterrupted Sleep Period (FUSP) in Nocturia

Abstract

Abstract Introduction In nocturia, longer FUSP (time to first void) correlates with better quality sleep (Bliwise et al, JCSM 2015;11:53-5) and, with treatment, longer FUSP is associated with decreased nightly voids (Epstein et al, Neurourol Urodyn 2018;37:186-91). We examined urologic correlates of FUSP in an outpatient nocturia population without comorbidities (CHF, OSA, ESRD, diuretics). Methods Participants (n=119; men) kept a home flow/volume diary, tracking clock time and quantity of each urination across a 24-hr period. FUSP was defined as time between going to bed and time of first void. We analyzed the urine volume at first nocturnal void (FNVV) (i.e., at end of FUSP). We also analyzed all nighttime volumes and divided by reported hours of sleep to impute nocturnal urine production (NUP) (in ml/hr, classified as high [>90 ml/hr] [n=49] vs low [<90 ml/hr] [n=60])—a measure correlated with number of nocturia episodes (van Doorn et al, J Urol 2014;191:1034-9). Nocturnal maximal voided volume (NMVV) at any single nocturnal void defined maximal functional nocturnal bladder capacity. Data were analyzed non-parametrically. Results For 53 of 119 patients, FNVV was identical to NMVV. This was more likely in patients with NUP >90 ml/hr vs <90 ml/hr (59% vs 40%, p=.046). High (vs low) NUP rates were also associated with higher FNVV (300 [225-420] vs 135 [100-200] ml, p<.001), as well as higher number of voids (3 vs. 2, p=.03). Conclusion For nearly half of these nocturia patients, the volume at first void occurred at their maximal nocturnal volume. In nocturia, higher FNVV also reflects greater overall nocturnal volume of urine produced, and excess urine volume (as opposed to insufficient bladder capacity) likely plays a central role in the pathogenesis of nocturia in these patients. The extent to which these higher initial volumes represent free-water vs solute-driven clearance is currently under investigation. Support N/A