Atherosclerosis, Cholesterol, and Diabetes
Atherosclerosis, Cholesterol, and Diabetes
American Diabetes Association
Drexel H, Aczel S, Marte T, et al.: Is atherosclerosis in diabetes and impaired fasting glucose driven by elevated LDL cholesterol or by decreased HDL cholesterol? Diabetes Care 28:101-114, 2005.
What is the problem and what is known about it so far?
People with diabetes are more likely to have -- and die from -- cardiovascular problems (like a heart attack or stroke) than those without diabetes. Some studies show that high LDL (ÏbadÓ) cholesterol and low HDL (ÏgoodÓ) cholesterol in people with diabetes is a strong sign they'll have a future heart attack. This is true even after patients improved their blood glucose and blood pressure levels. However, it is still not clear which problem -- high LDL or low HDL -- is worse.
Why did the researchers do this particular study?
The researchers wanted to find out which problem, a high LDL level or a low HDL level, is more common in people with diabetes. They compared people with diabetes to people without diabetes but with higher-than-normal blood glucose levels (impaired fasting glucose, a sign of future diabetes) and to people with normal glucose levels. They wanted to find out whether high LDL or low HDL was more closely tied to atherosclerosis (a hardening of the arteries) and which one was a stronger sign of a future heart attack or stroke.
Who was studied?
The researchers studied 750 patients. Some had heart disease, and the others were thought to have heart disease.
How was the study done?
The patients were put into three different groups: those with normal fasting glucose levels, those with elevated fasting glucose levels, and those with type 2 diabetes. After 2 years, the patients had follow-up exams. Researchers noted if people had strokes or heart attacks and measured their cholesterol, glucose, and insulin levels.
What did the researchers find?
People who had high blood glucose levels were more likely to have low HDL cholesterol and high triglycerides. For patients with heart problems and type 2 diabetes, low HDL cholesterol and high triglycerides were linked with coronary artery disease (disease of the heart's blood vessels) and were a strong sign of future heart attacks or strokes.
What were the limitations of the study?
Many of the patients were on medicine to lower their LDL cholesterol. If they hadn't been on this medicine, there might have been a bigger link between LDL cholesterol and heart disease. Also, a study with more patients for a longer period of time might show a bigger link between LDL cholesterol and heart attacks and strokes. This study examined patients that were already at high risk for coronary artery disease, so the results aren't necessarily true for low-risk patients.
What are the implications of the study?
Many of the patients in this study were taking medicine to lower LDL cholesterol and to reduce the risk of future heart problems. Medicine and treatment that both raise HDL cholesterol and lower LDL cholesterol can help prevent heart attacks and strokes in patients with diabetes. We need more studies to look at HDL-raising and LDL-lowering medicines that can be taken safely at the same time.
American Diabetes Association
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