A community-based study of insomnia in Hong Kong Chinese children: Prevalence, risk factors and familial aggregation.
OBJECTIVE
There has been limited data on familial aggregation of insomnia. We aimed to explore the prevalence, risk factors and familial aggregation of childhood insomnia with a large community-based sample.


METHODS
A community-based epidemiologic study of sleep disorders was conducted among primary school children. Those children with at least one reported biological parent were recruited. A total of 5695 children (mean age 9.2; SD 1.8), 4939 of their reported biological mothers (mean age 38.9; SD 4.6) and 4289 of their reported biological fathers (mean age 43.3; SD 5.5) were studied.


RESULTS
The rates of insomnia 3 times/week in the past 12 months were 4.0%, 12.8% and 9.7% for children, mothers and fathers, respectively. A robust familial aggregation of insomnia was found even after adjustment of the shared environmental and socio-demographic factors. There was a significant dose-response relationship among the children across their parental status from neither, fathers, mothers to both parents with insomnia [3.0%, 7.1%, 9.5% and 11.9%; with ORs (95% CIs)=2.48 (1.82-4.37) for fathers, 3.42 (2.55-4.59) for mothers and 4.42 (2.42-8.10) for both parents, respectively]. In addition, the frequency of insomniac symptoms of the parents also had a dose-response effect on the rate of insomnia of their children.


CONCLUSIONS
Insomnia is a common problem in both children and their parents. A significant familial aggregation of childhood onset insomnia was seen in this study even after adjustment of the co-risk factors. There was a dose-response effect of parental insomnia on the rate of insomnia of their children with a slight predilection of maternal influences.
Zhang
Jihui
J
Department of Psychiatry, The Chinese University of Hong Kong, Shatin, Hong Kong.
Li
A M
AM
Kong
A P S
AP
Lai
K Y C
KY
Tang
N L S
NL
Wing
Y K
YK
D000293:Adolescent; D000328:Adult; D044466:Asian People; D002648:Child; D015331:Cohort Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D006723:Hong Kong; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D007319:Sleep Initiation and Maintenance Disorders / Q000208:ethnology* / Q000235:genetics*; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires