Desmopressin response in nocturnal enuresis showing concentrated urine

In Japan, the use of desmopressin (1-desamino-8-D-arginine vasopressin) is only recommended for nocturnal enuresis with unconcentrated first morning urine, which suggests a relative deficiency of antidiuretic hormone secretion during sleep. However, no such limitations have been described in a standardization document of the International Children's Continence Society. We aimed to determine whether desmopressin treatment induces any response in nocturnal enuresis with concentrated first morning urine.

Outpatients aged 6-15 years who exhibited monosymptomatic nocturnal enuresis were examined. Data were obtained from 41 treatment-naive patients (median age 9.7 years) with nocturnal enuresis, who received desmopressin as their first line of treatment. The patients were divided into two groups demonstrating unconcentrated (osmolality < 800 mOsm/L, Low-Osm group) and concentrated (osmolality ≥ 800 mOsm/L, High-Osm group) first morning urine, respectively; we compared the response to desmopressin treatment between the groups at 1 month after the administration or updosing of desmopressin; responses were defined as partial or complete according to the International Children's Continence Society standards. Mann-Whitney U-tests or Fisher's exact tests were used for analysis.

The Low-Osm (median age 9.6 years) and High-Osm groups (median age 9.7 years) had 14 and 27 patients, respectively; the response rates to desmopressin treatment were 64.3% and 59.2%, respectively, indicating no significant differences (P = 0.99).

Desmopressin treatment may be a feasible option for treating nocturnal enuresis with concentrated first morning urine.