There is a well-documented relationship between short sleep duration and high body mass index (BMI). The mechanism linking short sleep duration and weight gain is unknown. Current studies in healthy young volunteers have shown that experimental sleep restriction is associated with dysregulation of the neuroendocrine control of appetite and with alterations in glucose metabolism. The goal of our study is to determine the metabolic and hormonal modifications induced by chronic sleep curtailment in obese adolescents and young adults and to observe if short sleep is a negative prognostic factor in their weight evolution.

The main purpose of the study is investigate whether the concentrations of 2 hormones that regulate appetite (leptin, ghrelin), cytokines (TNF-a, IL-6) and CRP are modified in obese adolescents and young adults who had sleep disorders in comparison to obese adolescents and young adults who sleep longer.

Inclusion Criteria:

• 13-25 years old
• BMI > 30 kg/m2 (If adolescents aged under 18 years: BMI equivalent to a BMI for age and sex to a BMI of 30, according to the Cole et al. obesity criteria).

Exclusion Criteria:

• Infection
• Liver disease
• Chronic inflammatory disease
• Endocrine disease
• Use of drugs that alter the sensitivity of insulin

Patients of the output clinics in the endocrinology and pediatric endocrinology departments at the university hospital.