Diabetes patients requiring glucose-lowering therapy and nondiabetics with a prior myocardial infarction carry the same cardiovascular risk: A population study of 3.3 million people

Background - Previous studies reveal major differences in the estimated cardiovascular risk in diabetes mellitus, including uncertainty about the risk in young patients. Therefore, large studies of well-defined populations are needed. Methods and Results - All residents in Denmark >= 30 years of age were followed up for 5 years ( 1997 to 2002) by individual- level linkage of nationwide registers. Diabetes patients receiving glucose- lowering medications and nondiabetics with and without a prior myocardial infarction were compared. At baseline, 71 801 ( 2.2%) had diabetes mellitus and 79 575 ( 2.4%) had a prior myocardial infarction. Regardless of age, age-adjusted Cox proportional- hazard ratios for cardiovascular death were 2.42 ( 95% confidence interval [ CI], 2.35 to 2.49) in men with diabetes mellitus without a prior myocardial infarction and 2.44 ( 95% CI, 2.39 to 2.49) in nondiabetic men with a prior myocardial infarction ( P = 0.60), with nondiabetics without a prior myocardial infarction as the reference. Results for women were 2.45 ( 95% CI, 2.38 to 2.51) and 2.62 ( 95% CI, 2.55 to 2.69) ( P = 0.001), respectively. For the composite of myocardial infarction, stroke, and cardiovascular death, the hazard ratios in men with diabetes only were 2.32 ( 95% CI, 2.27 to 2.38) and 2.48 ( 95% CI, 2.43 to 2.54) in those with a prior myocardial infarction only ( P = 0.001). Results for women were 2.48 ( 95% CI, 2.43 to 2.54) and 2.71 ( 95% CI, 2.65 to 2.78) ( P = 0.001), respectively. Risks were similar for both diabetes types. Analyses with adjustments for comorbidity, socioeconomic status, and prophylactic medical treatment showed similar results, and propensity score - based matched- pair analyses supported these findings. Conclusions - Patients requiring glucose- lowering therapy who were >= 30 years of age exhibited a cardiovascular risk comparable to nondiabetics with a prior myocardial infarction, regardless of sex and diabetes type. Therefore, requirement for glucose- lowering therapy should prompt intensive prophylactic treatment for cardiovascular diseases.