The Effects of Smoking and Airway Restriction on Subclinical Atherosclerosis

Mihrican Yeşildağ,1 Zeynep Keskin,2 Durdu Mehmet Yavşan,3 Taha Tahir Bekci,1 Usame Omer Osmanoglu4 1Department of Chest Diseases S.B University Konya Training and Research Hospital, Konya, Turkey; 2Department of Radiology, S.B University Konya Training and Research Hospital, Konya, Turkey; 3Department of Chest Diseases, Necmettin Erbakan University Meram Faculty of Medicine, Konya, Turkey; 4Department of Biostatistics, Karamanoğlu Mehmetbey University Faculty of Medicine, Department of Biostatistics, Karaman, TurkeyCorrespondence: Mihrican Yeşildağ, Department of Chest Diseases, S.B University Konya Training and Research Hospital, Konya, 42090, Turkey, Tel +90 5057728296, Email [email protected]: Chronic obstructive pulmonary disease (COPD) is a chronic disease associated with systemic inflammation that may accelerate the atherosclerotic process. Smoking is a common risk factor for COPD and atherosclerosis. The goal of this study was to investigate the effects of COPD and smoking on carotid intima–media thickness (CIMT), in order to emphasise their importance in terms of subclinical atherosclerosis.Materials and Methods: The study involved 208 male patients aged 45– 65 years and was designed as a prospective, observational case-control study. Patients were separated into three groups, as follows: Group 1—non-smokers without airway obstruction (control) (n= 70); Group 2—smokers without airway obstruction (n= 70); and Group 3—smokers with airway obstruction(COPD) (n= 68). They were also classified into thickened CIMT (≥ 0.8mm) and normal CIMT (< 0.8mm) groups. Pulmonary function tests (PFT), carotid Doppler ultrasound, and biochemical and haematological tests were applied to all the participants.Results: CIMT values were markedly increased in the COPD group (1.00 [0.90– 1.30] mm), compared to the smoker group without airway obstruction (0.70 [0.58– 0.90] mm) and the non-smoker control group (0.60 [0.50– 0.70] mm). The factors associated with CIMT were FEV₁/FVC ratio (Exp B 0.0952, p=0.003), age (Exp B 1.082, p< 0.001), and cigarette pack-years (Exp B 1.030, p=0.020). In feature importance analysis, the most influential factor on CIMT was the FEV₁/FVC ratio (0.54) indicating COPD, followed by age (0.33) and cigarette pack-years (0.13).Conclusion: Among the factors influencing CIMT, the impact of a decreased FEV₁/FVC ratio was found to be the highest. Therefore, screening with carotid US should be considered for the early detection of subclinical atherosclerosis in patients with COPD.Keywords: atherosclerosis, CIMT, COPD, pulmonary function, smoking