Smoking, diabetes and cardiovascular diseases in men in the Asia Pacific region.

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. 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. 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. 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.