Johan Vande Walle

Background The first uninterrupted sleep period (FUSP, time up to the first episode of enuresis/nocturia after falling asleep) is a frequently investigated parameter in adults with nocturia, as it correlates with quality of life. However, it has not been included in pediatric enuresis studies. Aim Investigate FUSP, circadian renal water and sodium handling, as well as sleep quality before and after desmopressin therapy in enuresis. Materials and Methods We conducted a post hoc analysis of a prospective study in 30 treatment‐naïve children with enuresis who underwent a video‐polysomnography and a 24‐h urine concentration profile before and after 6 months of desmopressin therapy. We analyzed FUSP, periodic limb movements in sleep (PLMS), and arousal indexes and their correlations with the urinary parameters. Results Sixteen children with a mean age of 10.9 ± 3.1 years had full registrations and were included in this subanalysis. After therapy, FUSP was significantly longer ( p < 0.001), and the PLMS index was lower ( p = 0.023). Significant differences in the circadian rhythm of diuresis (night/day diuresis, p = 0.041), nocturnal urinary osmolality ( p = 0.009), and creatinine ( p = 0.001) were found, demonstrating the increase of urinary concentration overnight by desmopressin, as well as a significant antidiuretic effect (diuresis [ p = 0.013] and diuresis rate ( p = 0.008). There was no correlation between the difference of FUSP, PLMS index, and urinary parameters. Nevertheless, despite this study being underpowered, there are indications of a correlation between nocturnal diuresis and diuresis rate. Results Our results support the need for further research regarding FUSP in children with enuresis, in accordance with nocturia studies in adults, as this parameter could be valuable in the follow‐up and evaluation of therapeutic strategies for enuresis.