• General quality of life: SF-36 [ Time Frame: 12 and 24 weeks ]
  Mean difference in the seven other following SF-36 subscales between groups:

  • Vitality (VT)
  • physical functioning (PF)
  • bodily pain (BP)
  • Role-physical (RP)
  • Role-emotionale (RE)
  • Social functioning (SF)
  • Mental health (MH)

  Each subscale ranges from 0 to 100. The higher the score, the better quality of life.
• Specific quality of life: Calgary Sleep Apnea Quality of Life Index (SAQLI) [ Time Frame: 12 and 24 weeks ]
  Mean difference in the SAQLI global score and score in the domain A, B, C and D between groups. The SAQLI is a 35-items instrument that captures the adverse impact of sleep apnea on 4 domains:

  • Daily functioning (A)
  • Social interactions (B)
  • Emotional functioning (C)
  • Symptoms (D)

  When the SAQLI is administered after a therapeutic intervention, a fifth domain (E) is completed (Treatment-related symptoms). Items are scored on a 7-point scale with "all of the time" and "not at all" being the most extreme responses. Item and domain scores are averaged to yield a composite total score between 1 and 7. Higher scores represent better quality of life. To obtain the global SAQLI score the sum of the mean domain scores A, B, C, and D is divided by 4. If Domain E has been used after a therapeutic intervention, the SAQLI score is obtained by summing the mean domain scores A, B, C, and D, subtracting the mean Domain E score and dividing by 4.
• Daytime excessive sleepiness [ Time Frame: 12 and 24 weeks ]
  Mean difference in the Epworth Sleepiness Scale (ESS) score between groups. The ESS is a 8-item questionnaire. ESS score can range from 0 to 24. The higher the ESS score, the higher daytime sleepiness.
• Subjective sleep quality [ Time Frame: 12 and 24 weeks ]
  Mean difference in the Pittsburgh Sleep Quality Index (PSQI) score between groups. The PSQI is a 19-item questionnaire which measures several different aspects of sleep, offering seven component scores and one composite score. The component scores consist of subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Each item is weighted on a 0-3 interval scale. The global PSQI score is then calculated by summing the seven component scores, providing an overall score ranging from 0 to 21, where lower scores denote a healthier sleep quality.
• Mood [ Time Frame: 12 and 24 weeks ]
  Mean difference in the Hospital Anxiety Depression Scale (HADS) score between groups. The HADS is a 14-item questionnaire. Seven of the items relate to anxiety and seven relate to depression. Each item on the questionnaire is scored from 0-3. Scores range from 0 to 21 for either anxiety or depression. The higher the scores, the more anxiety and depression symptoms are important.
• Depression [ Time Frame: 12 and 24 weeks ]
  Mean difference in the Beck depression inventory (BDI) score between groups. The BDI is a 21-item questionnaire which assess the severity of depression. Score range from 0 to 63. Higher values represent a worse outcome.
• Fatigue [ Time Frame: 12 and 24 weeks ]
  Mean difference in the Pichot scale score between groups. The Pichot Scale is a 8-item questionnaire to assess fatigue. The score ranges from 0 to 32. Higher score indicates greater fatigue.
• Blood pressure [ Time Frame: 12 and 24 weeks ]
  Mean difference in systolic and diastolic blood pressure measured at office as well as via a 24-h ambulatory blood pressure monitoring
• Weight [ Time Frame: 12 and 24 weeks ]
  Mean difference in weight (kg) between groups
• Height [ Time Frame: 12 and 24 weeks ]
  Mean difference in height (m) between groups
• Body-mass index (BMI) [ Time Frame: 12 and 24 weeks ]
  Mean difference in BMI (kg.m^2) between groups. Weight will be divided by the square of the height to report BMI in kg/m^2.
• Waist circumference [ Time Frame: 12 and 24 weeks ]
  Mean difference in waist size (cm) between groups
• Hip circumference [ Time Frame: 12 and 24 weeks ]
  Mean difference in hip size (cm) between groups
• Waist-hip ratio [ Time Frame: 12 and 24 weeks ]
  Mean difference in waist/hip ratio between groups
• Neck size [ Time Frame: 12 and 24 weeks ]
  Mean difference in neck circumference (cm) between groups
• Fat distribution [ Time Frame: 12 and 24 weeks ]
  Mean difference in fat-free mass and fat mass measured via bioimpedance analysis between groups
• Resting metabolism [ Time Frame: 12 and 24 weeks ]
  Mean difference in basal metabolic rate (BMR) between groups using indirect calorimetry
• Concentration of fasting glucose [ Time Frame: 12 and 24 weeks ]
  Mean difference in fasting glucose (mg/dL) between groups
• Rate of glycosylated haemoglobin [ Time Frame: 12 and 24 weeks ]
  Mean difference in glycosylated haemoglobin [HbA1c] (%) between groups
• Concentration of insulin [ Time Frame: 12 and 24 weeks ]
  Mean difference in insulin (mlU/L) between groups
• Concentration of total cholesterol [ Time Frame: 12 and 24 weeks ]
  Mean difference in total cholesterol (g/L) between groups
• Concentration of HDL cholesterol [ Time Frame: 12 and 24 weeks ]
  Mean difference in HDL cholesterol (g/L) between groups
• Concentration of LDL cholesterol [ Time Frame: 12 and 24 weeks ]
  Mean difference in LDL cholesterol (g/L) between groups
• Concentration of triglycerides [ Time Frame: 12 and 24 weeks ]
  Mean difference in triglycerides (g/L) between groups
• Concentration of ultrasensible CRP [ Time Frame: 12 and 24 weeks ]
  Mean difference in CRP-US (mg/L) between groups
• Respiratory events [ Time Frame: 12 and 24 weeks ]
  Mean difference in apnea-hypopnea index (AHI) during sleep between groups measured via ambulatory polygraphy
• Desaturation events [ Time Frame: 12 and 24 weeks ]
  Mean difference in oxygen desaturation index (ODI) during sleep between groups measured via ambulatory polygraphy
• T90% [ Time Frame: 12 and 24 weeks ]
  Mean difference in percentage time spent with an oxygen saturation (SpO2) < 90% (T90%) during sleep between groups using an oximeter.
• Nocturnal hypoxic load [ Time Frame: 12 and 24 weeks ]
  Mean difference in hypoxic load related to apnea-hypopnea events and to sleep stages between groups using an ambulatory polygraphy. The area under the desaturation curve (SpO2) associated with respiratory-events will be used to quantify the 'hypoxic load'.
• Autonomic Arousal Index (Aai) [ Time Frame: 12 and 24 weeks ]
  Mean difference in pulse wave amplitude (PWA) drop during sleep between groups using an ambulatory polygraphy
• Autonomic Arousal Area under the curve [ Time Frame: 12 and 24 weeks ]
  Mean difference in the sum of the autonomic arousal area under the curve (AUC) between groups using an ambulatory polygraphy
• Autonomic Arousal duration [ Time Frame: 12 and 24 weeks ]
  Mean difference in the sum of the duration of the PWA drops between groups using an ambulatory polygraphy
• CPAP withdrawal [ Time Frame: 12 and 24 weeks ]
  Proportion of CPAP withdrawal in each arms
• CPAP adherence [ Time Frame: 12 and 24 weeks ]
  Mean duration of CPAP use per night in each arms
• CPAP compliance [ Time Frame: 12 and 24 weeks ]
  Proportion of compliant patients (mean CPAP use > 4h per night) in each arm
• Medical visit [ Time Frame: 12 and 24 weeks ]
  Mean number of medical visits between groups
• Sedentary behaviour [ Time Frame: 12 and 24 weeks ]
  Mean difference in sedentary time (min per day) between groups using accelerometer
• Light physical activity (LPA) behaviour [ Time Frame: 12 and 24 weeks ]
  Mean difference in LPA time (min per day) between groups using accelerometer
• Moderate to vigorous physical activity [ Time Frame: 12 and 24 weeks ]
  Mean difference in MVPA (METs-min per week) between groups using accelerometer
• Exercise capacity [ Time Frame: 12 and 24 weeks ]
  Mean difference in the distance (m) on the incremental shuttle walking test (ISWT) between groups
• Postural stability [ Time Frame: 12 and 24 weeks ]
  Mean difference in balance stability (total displacement of the centre of pressure) between groups using a posturographic platform

While the specific impact of obstructive sleep apnea (OSA) on quality of life is well established, the impact of CPAP therapy on quality of life remains unclear. Yet, improving the quality of life of OSA patient is one of the main targets of treatment.

Both exercise and healthy diet are recommended in the management of overweight and obesity. This should improve quality of life as well as comorbidities associated with sleep apnea.

• Sleep Apnea
• Overweight and Obesity

• Other: Tailored intervention
  • The exercise program consists of 2 x 1.5-hour supervised nordic walking sessions weekly during 12 weeks and 1-hour unsupervised moderate physical activity per week from week 4.
  • The diet intervention includes one face-to-face consultation with a dietician and one telephone-based contact monthly, i.e. 6 diet interventions for 12 weeks.
  • Behavioural changes techniques will be included in diet and exercise interventions.
  Other Name: TINE
• Other: Control
  This intervention will include tailored instruction on CPAP use and standard advices on physical activity and nutrition at CPAP initiation.
  Other Name: CPAP

• Experimental: Tailored intervention

  In this group, participants will receive a comprehensive lifestyle program in addition to CPAP therapy which will include a supervised exercise program, diet interventions and behavioural counselling during 12 weeks.

  Then, participants will follow a real-world maintenance program from weeks 12 to 24. It will include one telephone-based contact per month with the study coordinator. Participants will be encouraged to maintain their lifestyle modification during this phase.

  Intervention: Other: Tailored intervention
• Active Comparator: Control
  Participant in this group will benefit from routine CPAP therapy management from week 0 to 24.
  Intervention: Other: Control

Inclusion Criteria:

• Patients newly diagnosed for obstructive sleep apnea and requiring CPAP therapy
• BMI>25and≤40kg/m2
• Low physical activity (< 150 min of MVPA per week)
• IAH≥15
• Able to give informed consent as documented by signature

Exclusion Criteria:

• Patients already treated for OSA or another sleep disorder
• Required use of supplemental oxygen
• Active infection, malignancy or chronic inflammatory disorders
• More than moderate alcohol use of > 14 drinks per week
• Severe depression defined by a BDI > 30
• Surgery within the previous 3 months
• Known cardiac or pulmonary disease contraindicating exercise training
• Patient with a bariatric surgery project or already operated
• Pregnant or lactating women
• Onset of a severe cardiac disease contraindicating exercise training
• Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, peripheral functional limitation.

• Swiss Lung Association
• Ligue Pulmonaire Vaudoise