As a Cardiac Risk Factor, Is Diabetes Always a Coronary Equivalent?

Having diabetes appears to be roughly equivalent to aging 15 years.

In identifying patients for whom therapy to lower risk for cardiovascular disease is appropriate, diabetes often is regarded as a cardiovascular risk factor equivalent to previous myocardial infarction. Most evidence supporting this equivalence, however, comes from studies of middle-aged or older people.

Investigators identified more than 379,000 adults (age, >20) from Ontario who had diabetes in 1994 and more than 9 million adults who did not have diabetes. Data were extracted on acute MIs and deaths in this cohort from 1994 through 2000 (as well as data on "previous" MIs that had occurred from 1991 to 1994).

In both the diabetic and the nondiabetic groups, risk for MI increased with age. Compared with nondiabetics, diabetics were about 15 years younger when they crossed transition points from low risk (<10 MIs or deaths per 1000 person-years) to moderate risk (10–19 events) and from moderate risk to high risk ( ≥20 events). Among older men (age range, 50–65), risk for MI was similar for those with diabetes but no previous MIs and for those with previous MIs but no diabetes. However, in younger men and in women of all ages, diabetics without previous MIs had lower risks than nondiabetics with previous MIs.

Comment: As a cardiac risk factor, diabetes appears to be roughly equivalent to aging 15 years, but it does not appear to be a coronary equivalent in all groups (especially younger men and women [age, <40]). Achieving very low targets for blood pressure and lipids — which often require use of multiple drugs — might be less urgent for these patients, but longer follow-up is necessary to resolve that question.

— Bruce Soloway, MD

Citation(s):

Booth GL et al. Relation between age and cardiovascular disease in men and women with diabetes compared with non-diabetic people: A population-based retrospective cohort study. Lancet 2006 Jul 1; 368:29-36.