The main objective of the study is to identify the determinant of sleep characteristics of obese patients attempting a tertiary clinical center for obesity management, including bariatric surgery.

More accurately the questions addressed are:

• What are the determinants of the sleep habits (sleep duration, chronotype) and of their evolution
• What are the determinants of sleep breathing disorders (sleep apnea, obesity hypoventilation syndrome) and of their evolution

Adult obese patients, attempting a tertiary medical center for the management of their obesity, are asked to participate in a cohort study. Data issued from routine clinical practice are collected.

Medical history and actual medical condition:

• Type 2 or type 1 diabetes
• Dyslipidemia
• Hypertension
• Cardiovascular diseases
• Steatohepatitis/cirrhosis
• Gastric disorders
• Nutritional deficiency
• Obstructive sleep apnea/Obesity hypoventilation syndrome

All patients who do not have a previously known sleep apnea syndrome are evaluated by nocturnal polygraphy.

Lifestyle and sleep habits, as well as social and economic characteristics, are assessed by questionnaires.

Patients are asked to provide blood sample to constituate a serum bank and gene bank.

Patients are asked, if undergoing bariatric surgery, to provide subcutaneous and visceral fat.

When patients benefit from bariatric surgery, follow-up data are collected at 3 months, 6 months, 12 months after bariatric surgery and yearly after that for at least 5 years.

Inclusion Criteria:

• Class II or class III obesity (BMI ≥ 35 kg/m²). Only patients undergoing surgery to realize a second surgical line of management of their obesity may have a lower BMI, if the surgical recovery is motivated by a technical defect of the first assembly.

Exclusion Criteria:

• Refusal to participate.

Adult patients with class II or class III obesity (Body mass index ≥ 35kg/m²)