Diabetes alone is NOT a coronary risk equivalent to a history of myocardial infarction

Clinical Question:
Is diabetes alone a coronary heart disease risk equivalent to a history of prior myocardial infarction?

Bottom Line:
This meta-analysis found no evidence to support the contention that diabetes alone is a coronary heart disease (CHD) risk equivalent to a history of prior myocardial infarction (MI). The blanket use of aspirin and statins for patients with type 2 diabetes, regardless of their lipid levels, is not supported by the evidence. (LOE = 2a)

Reference:
Bulugahapitiya U, Siyambalapitiya S, Sithole J, Idris I. Is diabetes a coronary risk equivalent? Systematic review and meta-analysis. Diabet Med 2009;26(2):142-148.

Study Design:
Meta-analysis (other)
Funding:
Self-funded or unfunded
Setting:
Inpatient (any location) with outpatient follow-up

Synopsis:
Many clinicians believe that patients with diabetes without a history of MI have a similar risk of CHD to those without diabetes with a history of MI. As a result, aggressive treatment for prevention of CHD is often pursued in patients with type 2 diabetes, including widespread use of aspirin and statins, regardless of lipid levels. These investigators thoroughly searched multiple databases, the Cochrane Registry of Controlled Trials, and reference lists from retrieved articles for cohort or observational studies identifying total CHD events in patients with diabetes and no previous MI and those without diabetes and previous MI. Two independent reviewers performed the search and assessed individual study eligibility. Disagreements were resolved by consensus and review with a third individual. Thirteen studies including a total of 45,108 patients met inclusion criteria. Duration of follow-up ranged from 5 years to 25 years. Overall, patients with diabetes alone and no MI had a significant 43% lower risk for total CHD events compared with nondiabetic patients with prior MI. There was minimal heterogeneity in the results, with the reduced risk for total CHD events among diabetic patients with no prior MI reported as significant in 11 of the 13 individual trials.