07/01/2009 - Articles

Drug may help in diabetes complication

By: Susan Aldridge, medical journalist, PhD


Diabetic retinopathy is a significant complication of type 2 diabetes. A new clinical trial shows that the drug candesartan can slow progression of this condition and so may protect against loss of vision.


Diabetes has several complications which have a long-term impact on health. One is retinopathy, an eye condition which can impair vision. A new trial shows that the drug candesartan can help slow progression and even regress retinopathy, so that some protection of vision is conferred by treatment.


Diabetic eye disease, including retinopathy, is the leading cause of vision loss among younger people. And at diagnosis, nearly 40 percent of those with type 2 diabetes have some degree of retinopathy, and another 22 percent are likely to develop it over the next six years. We know that strict control of blood glucose significantly reduces the risk of progression of diabetic eye disease, as does control of blood pressure.

Angiotensin receptor blockers are a new group of drugs which are now recommended to reduce complications of diabetes. But it is not known if they can reduce the risk of retinopathy. Candesartan is a well-known angiotensin receptor blocker.

What was done

Researchers in Denmark and England have carried out a trial of candesartan versus placebo in a group of people with type 2 diabetes with mild to moderate retinopathy. The research covered 309 centers worldwide. The 1905 participants received either candesartan or placebo and were followed up for about four years. Retinal photographs were taken on a regular basis to assess progression, or regression, of retinopathy.

What was found

In the candesartan group, retinopathy progressed in 17 percent compared to 19 percent in the placebo group. Analysis showed that there was a non-significant reduction of 13 percent in progression on active treatment, Regression of retinopathy was increased by 34 percent in the candesartan and group. Overall, there was a shift towards less severe retinopathy at the end of the trial among those on the active treatment.

What this study means

Retinopathy is a potentially very disabling complication of type 2 diabetes. Treatment with candesartan over a four year period may help protect the eyesight of those affected because it can even make the condition regress.


  • Effect of candesartan on progression and regression of retinopathy in type 2 diabetes (DIRECT-Protect 2) : a randomised placebo-controlled trial AK. Sjolie, R. Klein,  et al., The Lancet, October 18 2008, vol. 372, pp. 1385--1391
Created on: 11/21/2008
Reviewed on: 07/01/2009

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