Background: To assess whether there is a statistical interaction between smoking and diabetes that is related to the risk of cardiovascular disease (CVD) in men in the Asia Pacific region.
Methods: An individual participant data meta-analysis was conducted on 34 cohort studies, involving 16 492 participants with diabetes (47.4% smokers) and 188 897 without (47.6% smokers). Hazard ratios (HR) and 95% confidence intervals (CI) were calculated for smoking (stratified by study and adjusted for age) for those with and without diabetes.
Results: In men with diabetes, the HR (95% CI) comparing current smokers with non-smokers was 1.42 (1.10-1.83) for coronary heart disease, 1.10 (0.88-1.37) for total stroke and 1.15 (0.98-1.35) for total CVD. The corresponding figures for men without diabetes were 1.47 (1.33-1.61), 1.27 (1.16-1.39) and 1.35 (1.27-1.44), respectively. There was no evidence of a statistical interaction between diabetes and current smoking, the number of cigarettes smoked per day or quitting smoking. Smoking cessation was associated with a 19% reduction in CVD risk, irrespective of diabetes status.
Conclusions: The effects of cigarette smoking and smoking cessation are broadly similar in men with and without diabetes. In Asia, where there are high rates of smoking and a rapidly increasing prevalence of diabetes, strategies that encourage smokers to quit are likely to have huge benefits in terms of reducing the burden of CVD in men with diabetes.
© 2009 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Blackwell Publishing Asia Pty Ltd.