ODP366 Copeptin Improves Prediction of Treatment Response in Children With Monosymptomatic Nocturnal Enuresis

BACKGROUND: Monosymptomatic nocturnal enuresis, bedwetting of children older than 5 years, affects 10% of children, and increases psychosocial burden. Monosymptomatic nocturnal enuresiscan be treated with DDAVP, a vasopressin analogue. Not all children respond to DDAVP treatment, and no reliable treatment predictor has yet been established. We hypothesise that plasma copeptin, a surrogate marker for vasopressin, can be used to predict treatment response to DDAVP in children with monosymptomatic nocturnal enuresis. METHODS: In this prospective observational study, we included 28 children with monosymptomatic nocturnal enuresis. Number of wet nights were assessed prior to starting, 4 weeks, and 12 weeks following treatment with DDAVP. Plasma copeptin was measured in the morning and evening prior to starting DDAVP treatment and after 4 weeks of treatment. Initial daily dose wasDDAVP 120 mg and was increased to DDAVP 240 mg in children where treatment response was insufficient after 4 weeks. Treatment response was defined as >50% reduction in wet nights and divided into partial treatment response (50-99% reduction of wet nights per week) and complete treatment response (100% reduction of wet nights). The primary endpoint was prediction of treatment response following 12 weeks of treatment with DDAVP using plasma copeptin ratio (evening/morning copeptin) at baseline. RESULTS: Median [IQR] age of children with monosymptomatic nocturnal enuresis was 10 years [8. 0, 11.2], 75% were male. Median [IQR] number of wet nights at baseline was 5. 0 [2.8, 7. 0]. 18 children responded to DDAVP treatment at 12 weeks (partial treatment response 10 children, complete treatment response 8 children). To predict overall treatment response, the best copeptin ratio cut-off was 1.34 (sensitivity 55.56%, specificity 94.12%, AUC 70.6%). To predict partial treatment response, the best copeptin cut-off was 1.3 (sensitivity 55.56%, specificity 100%, AUC 73. 0%). To predict complete treatment response, the best copeptin cut-off was 1.34 (sensitivity 31.25%, specificity 90%, AUC 54.1%). In contrast, neither number of wet nights at baseline, age, BMI, or serum sodium alone or in combination with plasma copeptin improved outcome prediction. DISCUSSION: Our results indicate that plasma copeptin ratio is the best predictor for treatment response in children withmonosymptomatic nocturnal enuresis. Plasma copeptin ratio could thus be useful to identify children with the highest benefit of DDAVP treatment and improve individualized treatment of monosymptomatic nocturnal enuresis. Presentation: No date and time listed