Objective: To study the effect of orexin deficiency on metabolic and pubertal characteristics in narcoleptic children, we compared the metabolic and pubertal alterations between 15 children with narcolepsy with cataplexy (NC) and 15 control children matched for age, body mass index (BMI) z score.
Method: Narcoleptic data were collected from the Reference Center for Narcolepsy and control common obese data from the department of pediatric endocrinology in Mother-Childrens Hospital in Lyon, France. Narcoleptic patients underwent clinical interview, polysomnographic recordings, and human leukocyte antigen typing. Height, weight, BMI, waist circumference, arterial blood pressure and Tanner pubertal stage were evaluated in both children groups. Plasma lipid and glucose profiles were analyzed. When an altered pubertal development was clinically suspected, plasma concentrations of hypothalamic-pituitary-gonadal axis hormones were determined.
Results: In this study, all the narcoleptic children had cataplexy, HLA DQB10602 and were obese. Both narcoleptic and obese control children were 12.5 years (517), 50% male, had a median BMI 27.6 kg/m2 (2141) and BMI z score 3.6 SD (2.55). 73% of narcoleptic children had metabolic syndrome compared to 11% in control obese (P=0.004). Seven narcoleptic children had insulin resistance with an increased HOMA-IR index and 8 showed hepatitis steatosis. None of the common obese children had elevated HOMA-IR (P=0.04) and only one boy showed hepatitis steatosis (P=0.008). In the narcoleptic group: two girls and one boy had advanced puberty and three girls and two boys had precocious puberty. In the common obese children group: only one girl and one boy had advanced puberty (NS), none had precocious puberty (P=0.02).
Conclusion: BMI-independent metabolic and pubertal alterations in NC children suggest that orexin-A influences the etiology of this phenotype. A careful pubertal and metabolic follow-up of these patients is mandatory as well as tailored therapeutic management.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology