Metabolism and Sleep Apnea Treatment

Aim 1 Group:

Inclusion criteria:

* Age between 18-70 years
* Ability to provide consent

Exclusion criteria

* Body Mass Index (BMI) \> 40 kg/m2
* Prevalent myocardial infarction, coronary revascularization, heart failure, and stroke
* Type 1 or Type 2 diabetes mellitus
* Current or prior use of PAP or oral appliance therapy for OSA
* Use of oral corticosteroids
* Unstable medical conditions that may preclude enrollment in the protocol such as: uncontrolled angina and/or congestive heart failure, uncontrolled blood pressure or resistant hypertension, severe chronic obstructive pulmonary disease, cancer, and active psychiatric disease (e.g., major depression)
* Other sleep disorders (e.g., circadian rhythm disorder, self-reported habitual sleep duration \< 6h)
* Use of supplemental oxygen during wakefulness or sleep
* Central sleep apnea, obesity hypoventilation syndrome or Cheyne-Stokes respiration based on the home sleep test
* Resting awake Oxygen Saturation (SpO2) \< 90%

Aim 2 Group:

Inclusion criteria:

* Age between 18-70 years
* Ability to provide consent
* Moderate-to-severe OSA (AHI ≥ 15/h);
* Demonstration of Positive Airway Pressure (PAP) use of \> 4 h/night on 70% of the nights during 1-week run-in period
* Successful completion of all of the procedures for Aim 1.

Exclusion criteria:

* BMI: ≥ 40 kg/m2
* Type 1 or Type 2 diabetes mellitus
* Current use of PAP or oral appliance therapy for OSA
* Commercial driver or report of motor vehicle accident or near-miss due to sleepiness within the 2 previous years
* Epworth sleepiness score of 18 or more
* Use of oral corticosteroids
* Participation in another clinical trial
* Unstable medical conditions that may preclude enrollment in the protocol such as: uncontrolled angina and/or congestive heart failure, uncontrolled blood pressure or resistant hypertension, severe chronic obstructive pulmonary disease, cancer, and active psychiatric disease (e.g., major depression)
* Other sleep disorders (e.g., circadian rhythm disorder, self-reported habitual sleep duration \< 6h)
* Use of supplemental oxygen during wakefulness or sleep
* Central sleep apnea, obesity hypoventilation syndrome or Cheyne-Stokes respiration based on the home sleep test
* Resting awake SpO2 \< 90%