First uninterrupted sleep period in children and adolescents with nocturnal enuresis: Added value in diagnosis and follow-up during therapy

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 -naive 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.