We read with great interest the article entitled "Desmopressin response in nocturnal enuresis showing concentrated urine" by Akagawa et al.1 . In this retrospective study that included 41 children with monosymptomatic nocturnal enuresis (MNE) who had received 1-desamino-8-D-arginine vasopressin (DDAVP) as their first-line treatment, the response ratio to DDAVP was not significantly different between the Low-Osm and High-Osm groups (64.3% vs. 59.2%). The authors concluded that DDAVP may be a feasible option for treating cases of MNE with concentrated first morning urine. Although we agree with the authors, the optimal urine specific gravity (USG), which is a simpler test for NE, remains unclear.