Response to desmopressin as a function of urine osmolality in the treatment of monosymptomatic nocturnal enuresis: a double-blind prospective study

Pretreatment morning urine osmolality and oral desmopressin lyophilisate treatment outcome in patients with primary monosymptomatic enuresis

PURPOSE

To determine the association between urine osmolality (Uosm) in patients with primary monosymptomatic enuresis (PMNE) and response to desmopressin (dDAVP) lyophilisate.

METHODS

This was a prospective cohort study that included 419 children with enuresis seen in outpatient clinic between October 2017 and October 2019. Patient workup included symptom checklist, 48 h frequency/volume chart, kidney and bladder ultrasound, uroflow, urinalysis and culture, spot urine Ca/creatinine, and first-morning Uosm. Patients < 5 years, with secondary enuresis, or loss of follow-up were excluded. Oral dDAVP lyophilisate was recommended to all with PMNE and normal bladder capacity. After 1 month of therapy, initial success was assessed according to ICCS. Significant predictor variables for complete response were identified and analyzed using correlation coefficients and binary logistic regression.

RESULTS

There were 48 patients with PMNE who received dDAVP and were followed for treatment success. Partial and complete responses were achieved for 14 (29.2%) and 20 cases (41.7%), respectively. Older age and lower Uosm were found to be significantly in favor of complete response to dDAVP lyophilisate, P = 0.007 and 0.033, respectively. ROC analysis determined the Uosm of ≤ 814 mOsm/kg as a cut-off value for complete success (sensitivity 65% and specificity 75%, AUC = 68.2%). The odds ratio for complete success for selected cut-off value was 5.57 (95% CI 1.588-19.551, P = 0.007).

CONCLUSION

High pretreatment morning Uosm (> 814 mOsm/kg) might be suggestive of an alternative treatment to dDAVP lyophilisate in PMNE because of the higher risk of treatment failure.

The role of urine osmolality and ions in the pathogenesis of primary enuresis nocturna and in the prediction of responses to desmopressin and conditioning therapies

Aim of the study was to determine the role of nocturnal and daytime urine volume, osmolality and ion excretions in the pathogenesis of primary monosymptomatic enuresis nocturna (PMEN) and in the prediction of response to desmopressin and conditioning therapies. Fifty-five children with PMEN between the ages 5 and 15 years were included to the study. The patients were randomly divided into three groups Group 1: Twenty enuretics having intranasal desmopressin 1x 20 microg treatment for 2 months Group 2: Twenty enuretics having conditioning therapy for 2 months. Group 3: Fifteen enuretics having intranasal izotonic solutions as placebo. The control group consisted of 15 healthy children. Urine osmolality, sodium, potassium, chloride, magnesium and creatinine levels were investigated in both daytime and nighttime urines. Fractional sodium, potassium, magnesium, chloride excretions were calculated. Wilcoxon, Mann-Whitney U, Kruskal-Wallis, Chi-square, Student's t and Pearson correlation tests were performed. The ratio of night/daytime urine osmolality was significantly decreased in enuretic children. In addition, the ratio of night/daytime urine Cl and K excretions were also significantly decreased in enuretics. Response rate to desmopressin and conditioning treatments were statistically higher than placebo control. The difference between response rates of desmopressin and conditioning therapies was not found statistically significant. Pretreatment values of urine volume osmolality and ions were not observed as predictive factors in response to desmopressin or conditioning therapy. In conclusion, nightly decreased potassium and chloride excretions were found to have a role in the pathogenesis of primary enuresis nocturna. Urine volume, osmolality and ion excretions are not suggested to be used in the prediction of response to desmopressin and conditioning therapies.