Sleep duration and body mass index in children and adolescents with and without obstructive sleep apnea

The prevalence of pediatric obesity and short sleep duration has simultaneously increased in recent decades. Sleep plays a critical role in metabolic and endocrine regulation and insufficient sleep has been shown to be associated with changes in metabolism. Obesity, a major risk factor for obstructive sleep apnea (OSA), has been also associated with metabolic dysregulation. Despite this, no study investigating short sleep and obesity has addressed the potential confounder of OSA. The aim of this study was to investigate the association between short sleep duration and obesity in children with and without OSA. In this retrospective study, 306 children who underwent polysomnography between January and December 2010 were included. A diagnosis of OSA was made if the apnea/hypopnea index on polysomnography is a parts per thousand yen1. Typical sleep times were obtained by parental report. Short sleep duration was defined as a reduction of > 1 h from the minimum total sleep time (TST) recommended for age from the National Sleep Foundation (NSF). Overall, 32 % were obese, 39.5 % had short sleep duration, and 78 % had OSA. Children with OSA had a similar frequency of short sleep duration than those without (39.6 vs. 42.4 %, p = 0.950). In children with short sleep duration, the odds ratio for obesity was 2.5 (95 % CI 1.3-4.9; p = 0.009) compared to children with TST within normal limits even after accounting for the presence of OSA. A parental history of total sleep duration of only 1 h less than recommended per age by the NSF is associated with a higher risk for obesity in children independently of the presence of OSA.