Objective: To examine the dose-response relationship of smoking status with carotid atherosclerosis in 959 relatively healthy Chinese men.
Methods: 959 older Chinese men were selected from Guangzhou Biobank Cohort Study (GBCS) on cardiovascular disease. Personal histories were collected and fasting plasma glucose and lipids, blood pressure, and common carotid artery intima-median thickness (CCA-IMT) were measured.
Results: (1) Composition of the cases: 39.1% were non-smokers, 25.7% were former smokers and 35.2% were current smokers. The mean (95% confidence interval) carotid IMT was 0.78 (0.77 - 0.79) mm. 18.4% of the subjects had carotid IMT equal to or thicker than 1.0 mm while 34.1% had carotid plaque. (2) After adjusting for age, sex, physical activity, body mass index, fasting glucose, triglyceride, high-density lipoprotein cholesterol, systolic and diastolic blood pressure, compared to never smokers, current smokers had significantly increased risk for thicker IMT and carotid plaque [odds ratio (OR) = 1.82, 95%CI: 1.30 - 2.55 and OR = 1.95, 95%CI: 1.38 - 2.75, respectively, all P < 0.001]. The risk for thicker IMT and carotid plaque increased with the increasing amount (cigarettes/day) and duration of smoking (years) as well with cigarette pack-years (P for trend all ≤ 0.01).
Conclusion: An elevated risk with a clear dose-response relationship was found between cigarette smoking and carotid atherosclerosis. Quitting smoking or reducing the amount of smoking may lower the risk of atherosclerosis, preventing and controlling the occurrence of cardiovascular diseases, and reducing the related cardiovascular mortalities.