Overview of Obstructive Sleep Apnea (OSA)

Overview of Obstructive Sleep Apnea (OSA)

• OSA involves complete (apnea) or partial (hypopnea) upper airway collapse during sleep, leading to decreased oxygen saturation.
• Symptoms include loud snoring, witnessed breathing interruptions, and excessive daytime sleepiness.
• OSA can negatively impact cardiovascular health, mental health, quality of life, and driving safety.

Burden of Disease

• 6.4% of Canadian adults diagnosed with OSA, but many remain unaware.
• Men are twice as likely to have OSA compared to women.
• Individuals over 60 are three times more likely to experience OSA.
• In the U.S., 25-30% of men and 9-17% of women meet OSA criteria.
• High prevalence noted in Hispanic, Black, and Asian populations.

Epidemiology

• OSA linked with chronic health issues: obesity, diabetes, metabolic syndrome, anxiety, and depression.
• Moderate to severe OSA increases cardiovascular disease risks, leading to complications like atrial fibrillation, hypertension, stroke, and heart failure.

Pathophysiology

• OSA results from upper airway obstruction due to negative pressures during inhalation.
• Progressive narrowing in the retro palatal region contributes significantly.
• Airway narrowing often correlates with body mass index, indicating a blend of anatomical and neuromuscular contributors.

Diagnosis Criteria

• Apnea or hypopnea must last at least 10 seconds to be registered as an event.
• Diagnosis criteria include:
  • Patient reports of sleepiness, nonrestorative sleep, or fatigue.
  • Observations of snoring or breathing interruptions during sleep.
  • Existing diagnoses of hypertension, mood disorders, or other related conditions.
• Polysomnography or home sleep apnea testing required:
  • AHI of five or more obstructive events per hour indicates OSA.

Severity Classification

• Apnea–hypopnea index (AHI) measures frequency of events per hour during sleep.
• Severity levels:
  • Mild OSA: AHI ≥ 5 events/hour
  • Moderate OSA: AHI ≥ 15 events/hour
  • Severe OSA: AHI ≥ 30 events/hour

Treatment Options

• Continuous Positive Airway Pressure (CPAP) therapy is the first-line choice; it maintains airway patency by applying pressure.
• Oral Appliances reposition the jaw to alleviate airway obstruction; suitable for mild to moderate cases (AHI 5-30).
• Oral appliances often have better patient compliance than CPAP but may lead to TMJ issues.

Monitoring and Management

• Regular assessment for symptom improvement is essential.
• Recommendations include weight loss strategies, sleeping on the side, avoiding alcohol and sedatives, quitting smoking, and elevating the head during sleep.
• Addressing other breathing issues, like nasal congestion, is also crucial for managing OSA.