Sleep duration independently influences metabolic body size phenotype in children and adolescents: a population-based study.

BACKGROUND

Epidemiologic studies have found an association between sleep duration and obesity. However, the relationship between sleep duration and metabolic body size phenotype in children and adolescents remains unknown.

METHODS

In this cross-sectional study, 3650 participants (1946 boys and 1704 girls) from the Korean National Health and Nutrition Examination Survey 2007-2012 were classified into four phenotypes according to body mass index and metabolic heath status based on the definition of metabolic syndrome by NCEP-ATP III or the International Diabetes Federation. The four phenotypes were: metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW), metabolically healthy overweight (MHO), and metabolically unhealthy overweight (MUO). The associations between the four metabolic body size phenotypes and sleep duration, categorized as very short (≤5 h), short (6-7 h), normal (8-10 h), or long (≥11 h), were evaluated.

RESULTS

Sleep duration was shorter in the MUO group (7.0 ± 1.5 h) than in the MHNW (7.3 ± 1.4 h) or MUNW (7.8 ± 1.6 h) groups. After adjusting for age, sex, household income, and physical activity, compared with a normal sleep duration, very short sleep duration (≤5 h) was associated with a higher prevalence of being overweight/obese (26.4% vs 17.4%, p = 0.001), lower risk of being MHNW (0.711 (0.538-0.940), p = 0.017) or MUNW (0.478 (0.237-0.962), p = 0.039), and higher risk of being MHO (1.702 (1.193-2.428), p = 0.003). By contrast, long sleep duration (≥11 h) was associated with a higher risk of being MUNW (2.581 (1.124-5.928), p = 0.025).

CONCLUSIONS

Sleep duration may be independently associated with metabolic body size phenotype in children and adolescents.