Study objectives: To determine, in a clinical sample of obese adolescents, whether shorter sleep duration is associated with metabolic risk and obesity severity.
Design: Cross-sectional study.
Setting: Tertiary care weight-management clinic in Cincinnati, OH, USA.
Participants: 133 obese adolescents aged 10-16.9 years.
Interventions: N/A.
Measurements: Multifaceted sleep duration data were examined with fasting venipuncture and anthropometric data collected during clinical care.
Primary outcome: presence of metabolic syndrome.
Secondary outcomes: waist circumference, triglycerides, HDL-cholesterol, blood pressure, glucose, insulin resistance (HOMA-IR), and body mass index (BMI).
Predictors: Sleep duration by (1) parent-report, (2) self-report, and (3) multi-night actigraphy.
Analysis: Relationships between sleep duration and each outcome were examined via regression models, adjusted for potential confounders.
Results: Regardless of how measured, sleep duration showed no strong association with metabolic syndrome (OR 1.1 to 1.5, P = 0.2 to 0.8), BMI (β -0.03 to -0.01, P = 0.2 to 0.8), or most other outcomes. Lower triglycerides were predicted by shorter sleep duration by self-report (β 12.3, P = 0.01) and actigraphy (β 13.6, P = 0.03), and shorter parent-reported sleep duration was associated with higher HDL-cholesterol (β = -2.7, P = 0.002).
Conclusions: Contrary to expectations, sleep duration was not associated with metabolic outcomes, and showed limited associations with lipid profiles. Although inadequate sleep may affect other areas of functioning, it appears premature to expect that lengthening sleep will improve BMI or metabolic outcomes in clinical samples of obese adolescents.
Keywords: Sleep; adolescent; cross sectional studies; metabolic syndrome; obesity.