Hypoxemia During Sleep and the Progression of Coronary Artery Calcium

The aim of this study was to evaluate the associations between objective sleep parameters of obstructive sleep apnea (OSA) and progression of subclinical cardiovascular disease as measured by the coronary artery calcium (CAC) score. We reviewed the medical records of 196 patients who underwent both polysomnography (PSG) and repeated coronary artery computed tomography (CT) for screening purposes. For each participant, the first coronary CT scan was conducted within 12 months of PSG. Follow-up CT was performed voluntarily. The CAC score was log-transformed to obtain normally distributed data. We evaluated potential associations between various sleep parameters by analyzing overnight-attended PSG and CAC score progression over time. ST90 (total sleep time of SaO₂ < 90%), CT90 (percentage of time of SaO₂ < 90%), and degree of mean oxygen desaturation were significantly correlated with CAC score progression even after adjustment for confounders (age, sex, DM, HTN, hypercholesterolemia, BMI, and smoking status) (estimate = 0.004, p = .010; estimate = 0.009, p < .001; estimate = 0.027, p = .001; respectively). We also performed subgroup analysis and found that the progression of CAC score over time showed higher tendency when CT90 value was 2.73 or more (CT90 ≥ 2.73 group; estimate = 0.336, CT90 < 2.73 group; estimate = 0.194, p < .001 each). ST90, CT90 and mean oxygen desaturation are significant predictors of cardiovascular disease progression. Coronary artery status should be monitored repetitively in patients with hypoxemia during sleep.

Keywords: Coronary artery calcium; Hypoxemia during sleep; Obstructive sleep apnea; Subclinical cardiovascular disease.