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OSA-Related Hypertension — RACP Adult Medicine MCQ

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ModerateRespiratoryOSA-Related HypertensionRACP Adult Medicine

A 50-year-old obese man with BMI 40 and resistant hypertension (on 4 agents) has excessive daytime somnolence, loud snoring with witnessed apnoeas, and morning headaches. His Epworth Sleepiness Scale is 18. His office BP is 155/95 mmHg. Ambulatory BP shows non-dipping pattern (nocturnal BP does not fall >10%). What is the most likely cause of resistant hypertension?

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Correct answer: D — Obstructive sleep apnoea

Obstructive sleep apnoea is the most common identifiable cause of resistant hypertension (present in 60-70% of resistant hypertension patients). The non-dipping pattern on ABPM (nocturnal BP does not fall >10%) is characteristic of OSA-related hypertension. Treatment of OSA with CPAP modestly reduces BP (~2-3 mmHg). OSA should be screened for in all patients with resistant hypertension, particularly if obese.

Reference: Australasian Sleep Association – 2024; NHFA 2016 Hypertension