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Mixed Results from Major 5-Year US Diabetes Study

  • Art Chimes

A five-year study aimed at finding ways to reduce some complications of diabetes tried several approaches but failed to reduce the risk of heart attack and stroke. But the study did identify some effective ways to reduce common vision, kidney, and nerve-related problems.

The government-funded study is called ACCORD, which stands for Action to Control Cardiovascular Risk in Diabetes. The study included high-risk diabetes patients – typically older and obese, with a history of complications.

Mixed Results from Major 5-Year US Diabetes Study
Mixed Results from Major 5-Year US Diabetes Study

Some patients got medicine to aggressively reduce cholesterol or blood pressure or their blood sugar levels. They were compared with patients in a control group who got standard treatments.

None of the aggressive treatments significantly reduced the risk of heart attacks, strokes, or other cardiovascular complications.

In the blood pressure group, for example, ACCORD researcher William Cushman said the aggressively-treated group did lower their blood pressure.

"Despite that, our composite cardiovascular outcome of dying from cardiovascular events or having a non-fatal heart attack or a non-fatal stroke, that combined outcome was not significantly reduced."

One positive outcome from the ACCORD study was evidence supporting ways to improve what doctors call diabetes patients' microvascular conditions. The disease affects small blood vessels in a way that can damage nerves, kidneys and the eyes. So, Emily Chew of the National Eye Institute noted that aggressive lowering of blood sugar or cholesterol levels helped control the progression of eye disease.

"This is a very important outcome," Chew told reporters. "[Diabetes] is the leading cause of blindness in Americans, especially in the young, productive, working-age men and women. We have very effective treatments for it, but yet if we can prevent it, it's so much better than having laser [treatment] or vitrectomy."

Vitrectomy is a kind of eye surgery.

In another part of the ACCORD study, patients got intensive therapy to lower their blood sugar. After three-and-a-half years, the group getting intensive therapy was switched into the control group, to standard therapy, because they were dying at a higher rate.

Dr. Sue Kirkman of the American Diabetes Association says the study results leave open the possibility that aggressively lowering blood sugar can help younger patients who have suffered relatively few effects from the disease.

"On the other hand, if people have more advanced disease, known cardiovascular disease or suspected cardiovascular disease, known kidney disease, probably a shorter life expectancy, it's probably not beneficial to that patient and may be harmful to really push intensive glycemic [blood sugar] controls," said Kirkman

Results of the ACCORD study were announced at a news conference at the American Diabetes Association's annual science meeting in Orlando, Florida, and were published in The Lancet and The New England Journal of Medicine.