How Diabetes Affects the Heart

ACCORD Trials Update: Studying Cardiovascular Risk in Diabetes
In the past, the federal government began 3 studies to examine the effects of lowering blood glucose levels, blood pressure, and lipid levels. These are the National Heart, Lung, and Blood Institute-funded Action to Control Cardiovascular Risk in Diabetes trials—the ACCORD trials. These trials had 10,000 type-2 diabetes participants.

One study—on lowering blood glucose levels—was stopped 2 years ago because of an increase in morbidity. The other two studies continued and were published in The New England Journal of Medicine.

It's common knowledge that having type 2 diabetes significantly raises the risk of developing cardiovascular disease. When examining the results of lowering blood pressure, the 4,733 participants at significantly high risk for cardiovascular disease were randomly assigned to one of two groups.

The intensively-treated group (with 2,362 participants) aimed at a normal level of less than 120 mm Hg systolic blood pressure. The other group (with 2,371 participants) was treated with standard therapy and had a desired goal of systolic blood pressure less than 140 mm Hg. (Currently, the target blood pressure level is 130 mm HG or lower.)

The researchers followed up in four-and-a-half years. What they found was that serious adverse events in the intensive therapy occurred in 77 of their 2,362 member group. In the standard treatment group, there were only 30 adverse events in the 2,371 members.

The researchers concluded that targeting blood pressure to 120 mm Hg rather than to 140 mm Hg did not reduce the number of fatal or non-fatal cardiovascular events. In fact, side effects of a higher incidence of elevated levels of potassium and some measures of kidney function became more impaired.

Now, just a thought from Dr. Stephen Kopecky, who is a professor of medicine at Mayo Clinic—he says that the study did not include measures relating to lifestyle and how they might have changed the results if placed in the mix.

In the second ACCORD trial, adding a triglyceride-lowering drug to a statin did not provide any extra protection from heart attack, stroke, or death from heart disease.

The study included 5,518 participants who took Zocor, which is available generically. They were divided into 2 groups, one taking only the Zocor (simvastatin) and a placebo. The other group was also given Zocor but with TriCor, an Abbott Laboratory fibrate medication which lowers triglycerides and raises HDL.

The results showed an 8% risk reduction using the combination therapy; however, this did not meet the level of significance.

Currently, there is disagreement between experts as to whether combined therapy will continue or not. The reason is that some patients did benefit from taking both medications, but many physicians think that this is just an example of the FDA approving a medication that just didn't work.

More on Cardiovascular Events for People with Diabetes
Finally, we also noted in the same March 18 New England Journal of Medicine 2 studies from the Navigator Study Group, one examining Starlix (used to control diagnosed type 2 diabetes) and its effect on cardiovascular events in diabetes. The second study was on Diovan (an antihypertensive medication) and its effect on the incidence of diabetes and cardiovascular events.

The Navigator Study Group was funded by Novartis, the manufacturer of these 2 medications, to examine these effects using Starlix and Diovan. These 2 trials examined whether these medications could do something they were not developed to do.

Over 5 years, the researchers examined Starlix in 9,306 overweight people with impaired glucose tolerance and established risk factors for cardiovascular disease. They found that it had little effect on stemming the incidence of either diabetes or cardiovascular events such as heart failure, heart attacks, or strokes.

The Diovan trials had the same number of participants and the same 5 year follow-up. What they found was that the use of Diovan did reduce the percentage of newly diagnosed diabetes by 14%, but did not stem the incidence of cardiovascular events. The 14% reduction was not thought significant enough to give the medication to a population with glucose intolerance and no diabetes as a protective medication.

Read more about the study here.

Once again, lifestyle modifications such as exercise, weight loss, and decreased stress may well be an important part of the answer. These may take time and patience but they are safe and can bring positive changes in one's health.

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