In an obese patient with daytime fatigue and loud snoring, what diagnostic test confirms suspected obstructive sleep apnea?

In an obese patient with daytime fatigue and loud snoring, what diagnostic test confirms suspected obstructive sleep apnea?

• A. Sleep study (polysomnography)
• B. Chest X-ray
• C. ECG
• D. Fasting glucose test

Answer: (A)

Diagnosing obstructive sleep apnea relies on objective data collected during sleep, and the best way to obtain that is with a sleep study. Polysomnography records brain activity, eye movements, muscle tone, heart rate, breathing effort, airflow, oxygen saturation, and often CO2. This allows calculation of the apnea-hypopnea index and shows how often breathing stops or decreases during sleep, how long desaturations last, and how sleep is fragmented. In someone who is obese with daytime fatigue and loud snoring, this study provides direct evidence of repeated airway collapse during sleep, confirming the diagnosis and defining severity. Other tests don’t assess nocturnal airway collapse. Chest X-ray evaluates structure of the chest and lungs but not sleep-disordered breathing. ECG looks at heart rhythm, not sleep-related breathing events. Fasting glucose screens metabolic risk but does not diagnose sleep apnea. In selected patients, a home sleep apnea test can be used, but in-lab polysomnography remains the standard for confirming obstructive sleep apnea.

Diagnosing obstructive sleep apnea relies on objective data collected during sleep, and the best way to obtain that is with a sleep study. Polysomnography records brain activity, eye movements, muscle tone, heart rate, breathing effort, airflow, oxygen saturation, and often CO2. This allows calculation of the apnea-hypopnea index and shows how often breathing stops or decreases during sleep, how long desaturations last, and how sleep is fragmented. In someone who is obese with daytime fatigue and loud snoring, this study provides direct evidence of repeated airway collapse during sleep, confirming the diagnosis and defining severity.

Other tests don’t assess nocturnal airway collapse. Chest X-ray evaluates structure of the chest and lungs but not sleep-disordered breathing. ECG looks at heart rhythm, not sleep-related breathing events. Fasting glucose screens metabolic risk but does not diagnose sleep apnea. In selected patients, a home sleep apnea test can be used, but in-lab polysomnography remains the standard for confirming obstructive sleep apnea.