Clinical features of obese children with narcolepsy

Abstract

Objective To analyze the clinical characteristics of narcolepsy in children with obesity, and to evaluate the impact of obesity on narcoleptic children clinically. Methods Forty cases first diagnosed as narcolepsy were recruited in the study who to see doctors at the Department of Neurology, Children's Hospital of Capital Institute of Pediatrics, from July 2012 to January 2015.According to diagnostic criteria for obesity by the body mass index(BMI)growth curve for the Chinese children and adolescents, they were divided into the obese group and the nonobese group.The general clinical data of 2 groups were analyzed, and the related metabolic indexes and the whole night polysomnography(PSG) of 2 groups were studied. Results In this group, male versus female 3:1, obesity was found in 21 cases(52.5%) and nonobesity was found in 19 cases(47.5%) from the samples.The mean BMI of all patients was(21.55±3.11) kg/m2.The average BMI of the obese group was(23.09±2.46) kg/m2, and BMI of the non-obese group was(19.85±2.89) kg/m2.Obese children were younger at the onset of disease and by the time of diagnosis age [(7.94±2.22)years old, (8.76±2.36) years old] than nonobese children[(10.75±3.10)years old, (12.51±2.88) years old]. The fasting blood glucose and blood lipid in all patients were normal, and there was no significant difference between 2 groups.The total sleep time, sleep efficiency and the ratio of rapid eye movement(REM) phase of the obese group[(397.45±53.76) min, (68.70±8.90)%, (18.37±4.39)%]were significantly lower than those of the non-obese group [(449.95±86.49) min, (76.58±13.60)%, (22.19±6.34)%]. According to the sleep structure, the percentage of stageⅠnon rapid eye movement(NREM) sleep in the obese group[(20.90±6.38)%] was more than that in non-obese group[(16.26±4.22)%]. There was no difference between the percentage of stage ⅡNREM sleep in the obese group[(42.59±5.52)%]and the non-obese group[(38.54±8.74)%]. Stage Ⅲ+ Ⅳ(slow wave sleep) NREM sleep ratio in the obese group[(18.14±6.97)%] was significantly lower than that in the non-obese group[(22.60±5.69)%]. Conclusions Obesity is one of the most common comorbids in narcolepsy, which affects more than 50% of narcoleptic children, mostly younger at disease onset.The narcolepsy children with obesity has total sleep time decreased, sleep efficiency reduced and sleep structure disorder is more obvious.To improve the realization of obesity in narcolepsy children and early treatment is the key to the success of the therapy. Key words: Narcolepsy; Obesity; Child