Tight Control of Hyperglycemia and Dyslipidemia May Slow Progression of Diabetic Retinopathy

Laurie Barclay, MD

July 08, 2010

July 8, 2010 — Tight glycemic control and intensive control of dyslipidemia, but not of hypertension, slowed progression of retinopathy in patients with type 2 diabetes, according to the results of the large Action to Control Cardiovascular Risk in Diabetes (ACCORD) randomized trial, published online June 29 in the New England Journal of Medicine.

"We investigated whether intensive glycemic control, combination therapy for dyslipidemia, and intensive blood pressure control would limit progression of diabetic retinopathy in patients with type 2 diabetes," write Emily Y. Chew, MD, from the National Eye Institute, National Institutes of Health, in Bethesda, Maryland, and colleagues from the ACCORD Study Group. "Previous data suggest that these systemic factors may be important in the development and progression of diabetic retinopathy."

In ACCORD, 10,251 adults with type 2 diabetes at high risk for cardiovascular disease were randomly assigned to receive intensive or standard treatment for glycemia and also for dyslipidemia or for systolic blood pressure control. Targets were glycated hemoglobin levels lower than 6.0% vs 7.0% to 7.9% and systolic blood pressure lower than 120 or lower than 140 mm Hg. For dyslipidemia, intensive treatment was 160 mg daily of fenofibrate plus simvastatin, and standard treatment was placebo plus simvastatin.

To determine progression of diabetic retinopathy, the outcomes of the interventions at 4 years were assessed in 2856 participants. Progression was defined as 3 or more steps on the Early Treatment Diabetic Retinopathy Study Severity Scale, determined from 7-field stereoscopic fundus photography, or development of diabetic retinopathy requiring laser photocoagulation or vitrectomy.

Rates of progression of diabetic retinopathy at 4 years were 7.3% with intensive glycemic control vs 10.4% with standard treatment (adjusted odds ratio [OR], 0.67; P = .003), 6.5% with fenofibrate vs 10.2% with placebo (adjusted OR, 0.60; P = .006), and 10.4% with intensive blood pressure control vs 8.8% with standard treatment (adjusted OR, 1.23; P = .29).

Limitations of this study include data collection regarding retinopathy outcomes from fundus photographs at only 2 time points and inability to assess retinopathy status in a significant proportion of patients at 4 years.

"Intensive glycemic control and intensive combination treatment of dyslipidemia, but not intensive blood-pressure control, reduced the rate of progression of diabetic retinopathy," the study authors write.

In an accompanying editorial, Barbara E.K. Klein, MD, MPH, from the University of Wisconsin in Madison, noted that a longer follow-up period might be needed to show a protective effect of blood pressure lowering.

"Overall, the ACCORD Eye trial has added substantially to our knowledge and confidence about the importance of glycemic control in the progression of diabetic retinopathy," Dr. Klein writes. "The findings also strongly suggest the need for further evaluation of the potential importance of fenofibrate in our armamentarium of treatments for this condition."

The National Institutes of Health and related organizations supported this study. Financial relationships of the study authors and editorial are reported in the article, as are pharmaceutical companies that provided medications and/or supplies.

N Engl J Med. Published online June 29, 2010.


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