Habitual Sleep Duration and Risk of Childhood Obesity: Systematic Review and Dose-response Meta-analysis of Prospective Cohort Studies

Abstract

A meta-analysis of cross-sectional studies found that shorter-time sleep was correlated with increased risk of obesity in children. However, findings from prospective cohort studies were inconsistent. PubMed and other data resources were searched through May 2015. Twenty-five eligible studies were identified including 56,584 children and adolescents with an average 3.4-year follow-up. Compared with children having the longest sleep duration (~12.2 hours), kids with the shortest sleep duration (~10.0 hours) were 76% more likely to be overweight/obese (pooled odds ratio [OR]: 1.76; 95% confidence interval [CI]: 1.39, 2.23); and had relatively larger annual BMI gain (pooled β coefficient: 0.13; 95% CI: 0.01, 0.25 kg/m(2)). With every 1 hour/day increment in sleep duration, the risk of overweight/obesity was reduced by 21% (OR: 0.79; 95% CI: 0.70, 0.89); and the annual BMI gain declined by 0.05 kg/m(2) (β = -0.05; 95% CI: -0.09, -0.01). The observed associations were not appreciably modified by region, baseline age or the length of follow-up. Accumulated literature indicates a modest inverse association between sleep duration and the risk of childhood overweight/obesity. Further research is needed to determine the age and gender specified optimal hours of sleep and ideal sleep pattern with respect to obesity prevention in children.

Figure 1. Flowchart of study screening and selection.

Figure 2. Multivariable-adjusted OR and 95% CI of overweight/obesity in relation to sleep duration.

The overall estimates are obtained by using a random-effects model. The dots indicate the adjusted ORs comparing the lowest to the highest levels of sleep duration or every 1 hour/day increment in sleep duration. The size of the shaded square is proportional to the weight of each study. The horizontal lines represent 95% CIs. The diamond indicates the pooled OR. CI: confidence interval; OB: obesity; OR: odds ratio; OW: overweight.

Figure 3. Multivariable-adjusted β coefficient and 95% CI of annual BMI gain in relation to sleep duration.

The overall estimates are obtained by using a random-effects model. The dots indicate the adjusted β coefficients comparing the lowest to the highest levels of sleep duration or every 1 hour/day increment in sleep duration. The size of the shaded square is proportional to the weight of each study. The horizontal lines represent 95% CIs. The diamond indicates the pooled β coefficient. BMI: body mass index; CI: confidence interval.