Does smoking exposure affect response to treatment in children with primary monosymptomatic nocturnal enuresis?
BACKGROUND
There are many variables affecting the success of treatment in children with primary monosymptomatic nocturnal enuresis (PMNE). This study investigates the possible effect of cigarette smoke exposure on desmopressin treatment response in children with PMNE.


METHOD
The medical records of pediatric patients with PMNE between February 2018 and December 2018 were retrospectively reviewed. Those who had moderate (3-5 wet nights/week) and severe (>5 wet nights/week) PMNE were included in the study. All patients received 120 mcg of sublingual desmopressin. After 3 months of therapy, treatment response was classified as complete response (100% dry night), partial response (between 50% and 99%) and non-responsiveness (<49% improvement). Partial response or non-responsiveness is considered as treatment failure. The relationship between treatment response to desmopressin and exposure to cigarette smoke was evaluated. Moreover, the other risk factors for treatment failure were investigated.


RESULTS
A total of 81 children with the diagnosis of PMNE, with a mean age of 9.98 ± 2.62 years, were included in the study. The frequency of passive smoke exposure at home was 53.1%. Sixty-two patients (76.5%) had severe PMNE, and the response to desmopressin decreased with severity of symptoms. Non-responsiveness to treatment, partial response, and complete response were observed in 11 (13.6%), 23 (28.4%), and 47 (58.0%) of patients, respectively. Treatment failure (n = 34, 42%) was 55.8% in children exposed to smoke and 26.4% in those who were not (p = 0.001). Although univariate analysis revealed that the severity of symptoms and smoke exposure were associated with treatment failure, in multivariate analysis, the presence of smoke exposure was the only independent risk factor (OR = 3.214, 95% CI: 0.125-0.888; p = 0.024) (Summary Table 1).


CONCLUSION
Exposure to cigarette smoke is a changeable and important risk factor that reduces the success of desmopressin treatment in children with PMNE.