Sleep duration and hyperglycemia among obese and nonobese children aged 3 to 6 years

Objective: To investigate the association between sleep duration and risk of hyperglycemia among preschool Chinese children. Design: A population-based cross-sectional study. Setting: Seventy-one randomly selected kindergartens in Tianjin, China. Participants: Six hundred nineteen obese (body mass index z score ≥1.65) and 617 nonobese (body mass index z score <1.65) children aged 3 to 6 years were recruited and matched by age. Main Exposure: Sleep duration. Main Outcome Measures: Hyperglycemia, defined as a fasting glucose level of 100 mg/dL or higher. Results: Obese children were more likely to have shorter sleep duration (≤8 hours) compared with their nonobese counterparts (P<.001). Compared with those who slept for 9 or 10 hours per night, those who slept for 8 hours or less had a significantly higher likelihood of having hyperglycemia, controlling for age and sex (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.12-2.45). After further adjustment for other potential confounders, the association still remained statistically significant (OR, 1.64; 95% CI, 1.09-2.46). In the stratified multivariable analyses, those who were obese and slept for 8 hours or less had an increased risk of having hyperglycemia (OR, 2.12; 95% CI, 1.06-4.21) compared with those who were nonobese and slept for 9 hours or more. Conclusions: Shorter sleep duration is associated with an increased risk of having hyperglycemia among preschool Chinese children. Whether adequate sleep may help maintain euglycemia among children, especially for those who are overweight or obese, warrants further investigation.