Intensive glucose control reduces kidney disease by half in type 1 diabetes

Intensive glucose control soon after type 1 diabetes diagnosis reduces by half the long-term risk of developing kidney disease compared to conventional therapy, according to a study published in the November 12 issue of the New England Journal of Medicine.

“Achieving near-normal glucose levels in type 1 diabetes can be challenging. But our study provides strong evidence that reinforces the benefits of reaching the goal as early as possible to slow or prevent kidney disease and other complications,” said Ian H. de Boer, MD, a kidney specialist at the University of Washington and first author of the study.

The study by the Diabetes Control and Complications Trial (DCCT) followed 1,441 people with type 1 diabetes between 1983 and 1993. All participants averaged six years from the onset of the disease and had very mild or no complications.

Half of the patients followed intensive therapy. They kept their hemoglobin A1C readings at 6 percent or less with at least three insulin injections daily or an insulin pump and exercised frequent self-monitoring of their blood glucose. The other half received conventional therapy, which at the time was one or two insulin injections daily with daily blood glucose or urine testing.

Researchers followed up with those patients after an average of 22 years. In the standard therapy group, 46 had developed kidney disease and 16 developed kidney failure. Yet only 24 in the intensive therapy group developed kidney disease, with just 8 developing kidney failure. The patients who kept they blood glucose to near-normal levels did so for an average of six and a half years.

What's more, the findings confirm that intensive therapy can reduce other complications of diabetes such as eye and nerve damage.

The findings do not prove that intensive therapy prevents loss of kidney function and reduces kidney failure, since the number of participants in the kidney failure data was not statistically significant.

Funded by the National Institutes of Health, the study continues to follow 1,375 of the original participants to examine the long-term effects of intensive glucose control.

“The full benefit of treatment may not be seen for decades, especially for complications of diabetes, such as kidney disease, which can progress slowly but have devastating consequences,” said Griffin P. Rodgers, MD, director of the NIH's National Institutes of Diabetes and Digestive and Kidney Diseases (NIDDK), which oversaw the research.

Type 1 diabetes in adults affects five to ten percent of the nearly 26 million Americans living with diabetes. In type 1 diabetes, the body's immune system destroys pancreatic beta cells that produce insulin. The disease, which was previously called juvenile-onset diabetes, usually first appears in children and young adults.

Diabetes is the leading cause of kidney failure. Chronic kidney disease occurs in 35 percent of people with diabetes over age 20.

Source: National Institutes of Health