Apnea-Hypopnea Index (AHI)

•Observational— Strong observational link to CV events; CPAP-outcomes trials mixed

Why screen aggressively

OSA is one of the most under-diagnosed conditions in adult medicine — estimates suggest 80%+ of moderate-severe cases remain undiagnosed. Untreated OSA is associated with:

• 2–3× increased stroke and fatal cardiovascular event risk.
• Resistant hypertension.
• Atrial fibrillation.
• Type-2 diabetes.
• Cognitive decline / dementia incidence.
• Daytime sleepiness, motor-vehicle crashes.
• Worse quality of life and mood.

Who to test

• Habitual snorers, especially if witnessed apneas.
• Excessive daytime sleepiness.
• Resistant hypertension.
• Atrial fibrillation recurrence after ablation.
• Treatment-resistant heart failure.
• Stroke recovery.
• BMI >30 with any of the above.

Tests

• Polysomnography (in-lab): gold standard; measures AHI, oxygen desaturation, sleep architecture, limb movements.
• Home Sleep Apnea Test (HSAT): less expensive; reasonable for uncomplicated suspected OSA. Misses central apnoeas.

Treatment

• CPAP: gold standard for moderate-severe OSA.
• Mandibular advancement device (MAD): oral appliance for mild- moderate, or CPAP-intolerant.
• Positional therapy.
• Weight loss (10% weight loss often halves AHI).
• GLP-1 agonists — SURMOUNT-OSA showed tirzepatide reduces AHI significantly in obese OSA.
• Hypoglossal nerve stimulation (Inspire) for selected patients.

Related entries

Atrial fibrillation, Cardiovascular disease, Cognitive decline, Sleep optimization.