Restless legs symptoms in adolescents: epidemiology, heritability, and pubertal effects.
OBJECTIVE
We aimed to determine the prevalence, pubertal effect, familial aggregation, and heritability of restless legs (RLS) symptoms in Chinese adolescents. In addition, the correlates and consequences of RLS symptoms were examined.


METHODS
This was a population-based family study that involved 1549 adolescents (probands), their parents and siblings. RLS symptoms were assessed by a single question measuring the core features of RLS. Subjects with RLS symptoms for at least once per week were considered as abnormal. Impairment of daytime functions, behavioral problems, health status, and lifestyle practice were also documented.


RESULTS
The prevalence of RLS symptoms was 2.8% in adolescents and 7.4% in their parents with female preponderance. Gender difference of RLS symptoms emerged in mid-pubertal adolescents (Tanner stage 3 or above). RLS symptoms were closely associated with various sleep problems (range of ORs=2.24 to 32.5, p<0.05), except habitual snoring. They were also independently associated with impairment of daytime functions, poor general health and frequent temper outbursts but not caffeine or alcohol intake or cigarette smoking after adjustment for age, sex, and other comorbid sleep problems. RLS symptoms presented with a modest familial aggregation and heritability (h²±SE=0.17±0.04, p<0.001).


CONCLUSIONS
RLS symptoms are common in Chinese adolescents with significant health repercussions. Puberty plays a critical role in the emergence of gender difference of RLS symptoms, which are accounted for by both genetic and environmental factors.
Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region.
Jihui
J
Zhang
Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region.
Siu Ping
SP
Lam
Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region.
Shirley Xin
SX
Li
Department of Pediatrics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region.
Albert Martin
AM
Li
Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region.
Alice Pik-Shan
AP
Kong
Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong Special Administrative Region. Electronic address: ykwing@cuhk.edu.hk.
Yun-Kwok
YK
Wing
D000293:Adolescent; D000294:Adolescent Behavior; D000428:Alcohol Drinking / Q000453:epidemiology; D002681:China / Q000208:ethnology; D015897:Comorbidity; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D010290:Parents; D015995:Prevalence; D011627:Puberty; D012148:Restless Legs Syndrome / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics*; D017678:Sex Distribution; D012737:Sex Factors; D012893:Sleep Wake Disorders / Q000453:epidemiology*; D012907:Smoking / Q000453:epidemiology
Adolescents; Heritability; Pubertal effect; RLS