Quantitative analysis of carotid arterial calcification using airway CT in obstructive sleep apnea

To evaluate the relationship between obstructive sleep apnea (OSA) severity and carotid arterial calcification by quantitative analysis using airway computed tomography (CT).

This study included a total of 180 consecutive OSA patients aged 45-80years underwent polysomnography and airway CT between March 2014 and October 2016. The subjects were divided into three groups based on the results of the respiratory disturbance index (RDI): mild (RDI 5-14, n=29), moderate (RDI 15-29, n=50), and severe (RDI≥30, n=101). The extent of carotid arterial calcification on each airway CT scan was quantified according to the modified Agatston scoring method. Differences among the three groups in clinical characteristics including age, gender, body mass index (BMI), comorbid disease, blood pressure, total cholesterol, and carotid arterial calcification score (CarACS) were analyzed.

The severe OSA group showed significantly stronger predominance for male and smoker, higher prevalence of diabetes, and larger BMI than those of mild and moderate OSA groups. The mean CarACS was significantly different among the three groups (mild RDI: 4.3±13.4, moderate RDI: 7.4±28.8, severe RDI: 48.6±121.6, P=0.011). Univariate linear regression showed that RDI, age, hypertension, male sex and diabetes significantly influenced on the CarACS. In a multivariate linear regression model, the CarACS was related to age, male sex, and diabetes.

The patients with severe OSA showed larger CarACS and a higher prevalence of atherosclerotic risk factors. The CarACS was correlated with severity of OSA, which might be more dependent on the conventional risk factors of atherosclerosis.