Relationship Between Obstructive Sleep Apnea and Increased Thoracic Periaortic Adipose Tissue

Objective: Aim of this study is to demonstrate the increased thoracic periaortic adipose tissue volume which is related to increased cardiovascular risk in subjects with obstructive sleep apnea (OSA) compared to control group. Material and Methods: The study population consisted of 25 newly diagnosed OSA patients (mean (SD) age: 55.0 (±12.1) years, 64% were males) and 34 healthy volunteers (mean (SD) age: 53.2 (±11.8) years, 61.8% were males). Standard overnight polysomnography system had applied to all of the participant and apnea–hypopnea index (AHI) was calculated. In addition, all of the participants underwent thoracic radiographic assessment in the supine position, using an 8-slice multidetector computed tomography scanner and thoracic periaortic adipose tissue volume was measured. Control group and OSA group were compared according to demographic characteristics, anthropometrics measurements and laboratory findings. Results: In subjects with OSA, thoracic periaortic adipose tissue volume [50.3 (±14.9) cm3 vs. 19.6 (±8.4) cm3, p<0.001], apnea-hypopnea index (AHI) [19.9 (±9.5) vs. 2.7 (±1.1) p<0.001)], triglyceride [204.7 (±87.1) mg/dL vs. 145.1 (±40.2) mg/dL (p= 0.003)] and total cholesterol [204.7 (±39.6) mg/dL vs. 183.5 (±36.1) (p=0.041)] levels were significantly higher compared to the control group. While there was a positive correlation between thoracic periaortic adipose tissue and AHI, no correlation was found with the other parameters. In stepwise regression analysis, AHI emerged as a significant predictor of thoracic periaortic adipose tissue (r= 0.41, p= 0.038), contributing to 13.7% of its variability. In OSA subjects, no significant difference was noted in thoracic periaortic adipose tissue levels with respect to gender (p=0.72), total cholesterol (p= 0.53), triglyceride (p= 0.34), or smoking status (p=0, 32). Conclusion: Our findings indicate significantly higher values for thoracic periaortic adipose tissue in OSA than controls, being associated positively with dyslipidemia and strongly predicted by AHI levels in OSA subjects, while not differing with respect to gender, and smoking status.