Coronary artery disease or blockage of the arteries supplying the heart is the major cause of death in patients with diabetes mellitus. It can result in heart attacks, heart failure or angina. The risk of developing coronary artery disease in diabetic patients is known to be several times higher at every level of cholesterol. The multiple risk factor intervention trial (MRFIT) found that coronary artery disease risk in diabetic subjects at any given plasma cholesterol level was approximately four times greater than in non-diabetic patients. This is especially true in women who lose their "natural" protection against heart disease.

With respect to heart disease, diabetes mellitus is more than just a problem of high blood sugar. In contrast to eye and kidney disease, good blood sugar control alone is not enough to prevent the development of heart disease. Diabetes mellitus is associated with widespread abnormalities in the blood. Of particular importance to heart disease are the blood lipids, which includes cholesterol and triglyceride. High triglyceride and low HDL cholesterol (the good cholesterol) is often seen in diabetic patients. In addition, the LDL cholesterol (the bad cholesterol) in diabetics may be 10-15% higher than in non-diabetics.

In addition to the high risk of developing coronary artery disease, studies suggest that when diabetics develop blockage in the arteries supplying the heart, this is more extensive than in non-diabetic individuals. An acute myocardial infarction (heart attack) in patients with diabetes mellitus is associated with some special features. The risk of death following a heart attack is higher in diabetic individuals. The long term prognosis of survivors of heart attacks amongst diabetics is also less favourable than in non-diabetics. Further, patients with diabetes mellitus (DM) are more likely to have painless or unrecognised heart attack..

We cannot answer this question directly from the available scientific evidence at this time. There is good evidence from studies conducted in Australia and New Zealand, Norway and the United States of America, that lowering blood cholesterol levels will lower the risk of heart disease in patients with diabetes mellitus. Given the very high risk of heart disease in patients with diabetes mellitus, most doctors would agree that it is important to maintain low levels of blood cholesterol. When this cannot be achieved through changes in the diet and with exercise, it may become necessary to use drugs to lower the lipid levels. We await the results of several new studies designed specifically to answer this question in diabetics and we hope to keep you posted regarding the results. We can start to expect the results of these large studies around the year 2000.

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