The impact of diabetes and myocardial infarction on mortality from coronary heart disease

Type 2 diabetes is one of the fastest growing public health problems in both developed and developing countries (1).
Coronary heart disease (CHD) is the leading cause of death among patients with type 2 diabetes (2).
Epidemiological studies have indicated that patients with type 2 diabetes have a 2-4 times higher risk of CHD mortality than those without diabetes. In recent years, several studies compared the magnitude of the risk of prior history of type 2 diabetes and CHD on subsequent CHD mortality (3-8).
The analyses from a Finnish cohort study including both men and women (3) and from the Nurses’ Health Study including women only (5) found that the risk of CHD among diabetic patients without prior myocardial infarction was similar to that in non-diabetic subjects with prior myocardial infarction.
The result from the Health Professionals Follow-up Study including men only and the Atherosclerosis Risk in Communities Study including both men and women (8), reported that the magnitude for CHD or cardiovascular disease (CVD) mortality was weaker for diabetes than that associated with prior CHD (4, 8).
It is well known that women with diabetes will loose their relative protection against CVD (9). However, only two studies comprising both men and women attempted to find out whether sex differences in the risk for CHD mortality existed in patients with diabetes by comparing it with established CHD (6, 7). The analysis from the Framingham Study indicated that in men prior CHD signifies a higher risk for CHD mortality than prior diabetes (6).
However, this is reversed in women, with prior diabetes being associated with greater risk for CHD mortality (6). In the Hoorn Study, women with prior diagnosis of diabetes only had a risk of CVD events that was similar to that of non-diabetic women with prior CVD, whereas, non-diabetic men with prior CVD conferred a higher risk of CVD compared with men with prior diabetes and without prior CVD (7).
These studies found that both diabetes and myocardial infarction at baseline increased CVD mortality. Further research is needed to compare the impact of incident diabetes and myocardial infarction at baseline and during follow-up on CHD mortality among both men and women.

 The content of this article reflects the personal opinion of the author/s and is not necessarily the official position of the European Society of Cardiology.