In a five-year study of nearly 11,000 people, those with obstructive sleep apnea had a higher risk of sudden cardiac death. At greatest risk were those aged 60 and older with moderate to severe apnea (20 episodes an hour).

When their oxygen saturation levels dipped below 78 percent — preventing air from flowing into the lungs — their risk increased by 80 percent.

Memo to Underwriters:

In case anyone asks why we are so harsh on untreated OSA quote this study.

Article link here.

Link to the study abstract here.

RESULTS:

During an average follow-up of 5.3 years, 142 patients had resuscitated or fatal SCD (annual rate 0.27%). In multivariate analysis, independent risk factors for SCD were age, hypertension, coronary artery disease, cardiomyopathy or heart failure, ventricular ectopy or nonsustained ventricular tachycardia, and lowest nocturnal O2sat (per 10% decrease, hazard ratio [HR]: 1.14; p = 0.029). SCD was best predicted by age >60 years (HR: 5.53), apnea-hypopnea index >20 (HR: 1.60), mean nocturnal O2sat <93% (HR: 2.93), and lowest nocturnal O2sat <78% (HR: 2.60; all p < 0.0001).

CONCLUSIONS:

In a population of 10,701 adults referred for polysomnography, OSA predicted incident SCD, and the magnitude of risk was predicted by multiple parameters characterizing OSA severity. Nocturnal hypoxemia, an important pathophysiological feature of OSA, strongly predicted SCD independently of well-established risk factors. These findings implicate OSA, a prevalent condition, as a novel risk factor for SCD.