Biomaterial Database

Short sleep duration in middle childhood: risk factors and consequences. 2008

Gillian M Nixon, and John M D Thompson, and Dug Yeo Han, and David M Becroft, and Phillipa M Clark, and Elizabeth Robinson, and Karen E Waldie, and Chris J Wild, and Peter N Black, and Edwin A Mitchell

Ritchie Centre obr Baby Health Research, Monash Institute of Medical Research, Monash University, Melbourne, Australia.

OBJECTIVE To measure sleep duration in 7-year-old children; identify the determinants of sleep duration; and assess the association between short sleep duration and obesity, cognitive functioning, and behaviour. METHODS Longitudinal study with disproportionate sampling of the participants. METHODS Community. METHODS 591 seven-year-old children, of whom 519 had complete sleep data. METHODS Not applicable. METHODS Sleep duration was assessed by actigraphy. Other measurements included height, weight, BMI, percentage body fat as assessed by bioimpedance assay, intelligence (WISC-III) and behaviour (Strengths & Difficulties questionnaire, parent and teachers Conners Rating Scales). RESULTS Mean time in bed according to parental report was 10.9 hours (SD 0.8). Mean sleep duration by actigraphy was 10.1 (SD 0.8) hours. In multivariable analysis, sleep duration was longer on weekdays vs. weekend nights (31.5 min, P = 0.002), in winter (40.5 min), autumn (31.1 min), and spring (14.8 min) compared with summer (P <0.0001), and in those with younger siblings (11.7 min, P = 0.03). Sleep duration was shorter when bedtime was after 21:00 (-41.1 min, P <0.0001). In multivariable analysis, sleep duration <9 hours was associated with being overweight/ obese (BMI: OR = 3.32; 95% CI = 1.40, 7.87) with an increase of 3.34% body fat (P = 0.03), and this was not explained by physical activity or television watching. Short sleep duration was also associated with higher emotional lability scores (Conners Rating Scale Parent Form; P = 0.03). IQ (WISC-III) and attention deficit / hyperactivity disorder scores (both parent and teachers Conners Rating Scales) did not differ with sleep duration. CONCLUSIONS Sleep duration in 7-year-old children varies considerably among individuals. The duration is affected by weekday, season, and having younger siblings. Importantly, short sleep duration was shown to be an independent risk factor for obesity/overweight.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009765	Obesity	A status with BODY WEIGHT that is grossly above the recommended standards, usually due to accumulation of excess FATS in the body. The standards may vary with age, sex, genetic or cultural background. In the BODY MASS INDEX, a BMI greater than 30.0 kg/m2 is considered obese, and a BMI greater than 40.0 kg/m2 is considered morbidly obese (MORBID OBESITY).
D001824	Body Constitution	The physical characteristics of the body, including the mode of performance of functions, the activity of metabolic processes, the manner and degree of reactions to stimuli, and power of resistance to the attack of pathogenic organisms.	Body Constitutions,Constitution, Body,Constitutions, Body
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D002652	Child Behavior	Any observable response or action of a child from 24 months through 12 years of age. For neonates or children younger than 24 months, INFANT BEHAVIOR is available.	Behavior, Child
D003072	Cognition Disorders	Disorders characterized by disturbances in mental processes related to learning, thinking, reasoning, and judgment.	Overinclusion,Disorder, Cognition,Disorders, Cognition
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000204	Activity Cycles	Bouts of physical irritability or movement alternating with periods of quiescence. It includes biochemical activity and hormonal activity which may be cellular. These cycles are shorter than 24 hours and include sleep-wakefulness cycles and the periodic activation of the digestive system.	Activity Cycle,Cycle, Activity,Cycles, Activity
D001315	Australia	The smallest continent and an independent country, comprising six states and two territories. Its capital is Canberra.	Canton and Enderbury Islands,Christmas Island,Christmas Island (Australia)