Phenotyping Mechanistic Pathways for Adverse Health Outcomes in Sleep Apnea

Phenotyping Mechanistic Pathways for Adverse Health Outcomes in Sleep Apnea

Obstructive sleep apnea (OSA) is a highly prevalent disorder with adverse neurocognitive and cardio-metabolic outcomes. Continuous positive airway pressure (CPAP) is the gold standard therapeutic option to treat airway obstructions during sleep and thus, prevent its adverse cardiovascular and neurocognitive outcomes. Previous clinical trials, however, have largely failed to show a consistent impact of CPAP on these health outcomes.

One of the main limitations of these trials may be the inadequate characterization of OSA and its acute physiological consequences. By characterizing OSA based on the "apnea-hypopnea index (AHI)", there is a potential risk of negative results.

In this trial, the investigators intend to tackle this issue, by better characterization of OSA-related physiological consequences during sleep using physiologically driven metrics to capture the burden of OSA-related hypoxemia ("hypoxic burden"), autonomic response ("heart rate burden"), and sleep fragmentation ("arousal burden").

Inclusion criteria:

• Adults aged 21-80 years.
• Participants with a previous diagnosis of moderate to severe obstructive sleep will be eligible to enroll and attend the baseline study. Patients with a total apnea-hypopnea index greater than 15 events/hr on the baseline study will be eligible for further participation.

Exclusion criteria:

• Current treatment for obstructive sleep apnea (including CPAP, oral appliances, supplemental oxygen). Patients must be untreated prior to the baseline visit.

• Use of medications that might depress respiration (including opioids, barbiturates, benzodiazepines, and Z drugs, including zolpidem, zopiclone, eszopiclone, and zaleplon).

• Active use of non-prescription opioids (e.g., cocaine, methamphetamine)

• Uncontrolled medical problem or major organ system disease, which, in the opinion of the investigators (PI and Co-Is), would interfere with the evaluation of the subject (e.g., uncontrolled hypertension, unstable coronary heart disease, etc.).

• History of congestive heart failure, renal insufficiency, systemic neurological condition that could affect respiration.

• Sleep disordered breathing or respiratory disorders other than obstructive sleep apnea:

  • central sleep apnea (>50% of respiratory events scored as central),
  • chronic hypoventilation/hypoxemia (awake SaO2 < 92% by oximetry) due to chronic obstructive pulmonary disease or other respiratory conditions.

• Other sleep disorders: periodic limb movements (periodic limb movement arousal index > 10/hr), narcolepsy, or parasomnias.

• Patients unable or unwilling to use CPAP.

• Insomnia or insufficient sleep (self-reported inability to sleep >6 hrs night).

• Pregnancy (women)