Although diabetes mellitus is an established risk factor for coronary heart disease (CHD) and stroke, a number of questions remain. For example, to what extent is diabetes associated with fatal vs non-fatal myocardial infarction? How much of the effect of diabetes on vascular risk is due to the effect of diabetes on lipids and blood pressure? How much does the effect of diabetes vary according to age and sex?
This study was a meta-analysis of the individual records of diabetes, fasting blood glucose concentration, and other risk factors in people without vascular disease in the Emerging Risk Factor Collaboration. Hazard ratios (HRs) for vascular disease were calculated using within-study regressions that were adjusted for age, sex, smoking, systolic blood pressure, and body-mass index.
The analyses included data from 698782 people. Adjusted HRs with diabetes are shown in figure 1, and did not change appreciably after further adjustment for lipid, inflammatory, or renal markers. Hazard ratios were for coronary heart disease were noted to be higher in younger patients than older patients, in women than men, and in fatal than non-fatal disease. However, in people without diabetes, information about fasting blood glucose concentration or impaired fasting glucose status did not significantly improve metrics of vascular disease prediction when added to information about several conventional risk factors.

Conclusion:

In this large meta-analysis, diabetes was found to confer about a two-fold excess risk for a wide range of vascular diseases, independently from other risk factors.

• Emerging Risk Factors Collaboration. Diabetes mellitus, fasting blood glucose concentration, and risk of vascular disease: a collaborative meta-analysis of 102 prospective studies. Lancet 2010; 375: 2215-22

Figure 1: Hazard Ratios (HRs) for specific vascular outcomes in patients with versus those without diabetes at baseline