Objective: The aim of the present study was to evaluate the influence of sleep duration on cardiovascular risk factors in obese children.
Methods: Cross-sectional analysis of 90 obese children ages 7 to 16 years. Anthropometric and clinical evaluation with specification of dietary and lifestyle habits was carried out during an office visit. Sleep duration was evaluated by the BEARS (B = bedtime issues, E = excessive daytime sleepiness, A = night awakening, R = regularity and duration of sleep, S = snoring) questionnaire on children's sleep characteristics. Sleep time adequacy by age was assessed according to the criteria of the National Sleep Foundation. Biochemical blood variables indicative of metabolic risk (glucose, lipid profile, and insulin) were obtained. Emergent new factors of metabolic risk, including high-sensitive C-reactive protein, γ-glutamyltranspeptidase, homocysteine, retinol-binding protein 4 (RBP4), thyroid-stimulating hormone (TSH), inflammatory markers, and the adipokines leptin, adiponectin, and ghrelin were also evaluated. The relations between the duration of sleep and these variables were analyzed by general lineal model analysis. Significant variables were introduced in logistic regression analysis to determine the odds ratio (OR) and 95% confidence interval (CI) of cardiometabolic factors with respect to sleep.
Results: Children who slept for short duration were significantly more at risk of severe central obesity. In the regression model, the mean arterial pressure (odds ratio [OR] 1.10, 95% confidence interval [CI] 1.02-1.17, P = 0.008), homocysteine (OR 1.41, 95% CI 1.08-1.84, P = 0.013), RBP4 (OR 1.78, 95% CI 1.15-2.78, P = 0.010), and TSH (OR 2.01, 95% CI 1.21-3.34, P = 0.007) remain as significant independent predictors related to short sleep duration. We did not find any association between sleep duration and inflammatory markers or adipokines.
Conclusions: Short sleep duration increases the severity of obesity and is related to cardiovascular risk factors in children.