Issue 179 Item 7 Extended Delay in Progression of Diabetic Nephropathy Seen in P

Intensive diabetes treatment to sustain near-normal glycemia has an extended benefit of delaying the progression of diabetic nephropathy. That, according to the most recent findings of the Epidemiology of Diabetes Interventions and Complications (EDIC) study.

The EDIC trial, which originated in 1993 after the closeout of the Diabetes Control and Complications Trial (DCCT), followed 1349 participants of DCCT for the development of microalbuminuria, clinical-grade albuminuria, hypertension, or an increase in their serum creatinine level. "Follow-up of the DCCT cohort for 8 additional years in the EDIC study has shown persistent differences in nephropathic outcomes between the former intensive-treatment and conventional-treatment groups," writes David M. Nathan, MD, Massachusetts General Hospital, Boston, United States, and members of the combined DCCT/EDIC Research Group. They report results by intention-to-treat analyses of 676 patients in the original DCCT intensive treatment group and 673 patients in the original DCCT conventional treatment group.

During the EDIC study, new cases of microalbuminuria occurred in 6.8% of the DCCT intensive group compared with 15.8% of the DCCT conventional treatment group. New cases of clinical albuminuria occurred in 1.4% of the DCCT intensive group compared with 9.4% of the conventional DCCT group.

The investigators note there was no difference in the prevalence of hypertension between groups at the end of the DCCT (11% for both) but by year 8 of the EDIC follow up they report the prevalence of hypertension was 29.9% in the intensive group but was 40.3% in the conventional group.

The DCCT/EDIC Research Group found that, since the DCCT baseline through year 8 of the EDIC trial, a doubling of serum creatinine level occurred in 10 of the intensive treatment group and in 17 of the conventional treatment group. At EDIC year 8, only 5 patients in the intensive versus 19 in the conventional group reached serum creatinine levels of 2 mg/dL or greater and 4 of the patients in the intensive group compared with 7 in the conventional group required dialysis and/or kidney transplantation.

"The current results reaffirm that intensive treatment of type 1 diabetes should be initiated as early as is safely possible in order to provide strong and durable protection from the development and progression of diabetic microvascular disease," the authors conclude adding, "the protection initiated by intensive treatment appears to outlast the intensive treatment itself, although the duration of the effect remains to be determined." JAMA 2003;290:2159-2167

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