Intensive Control of Type 1 Diabetes Reduces Risk of GFR by 50%

According to a recent study, type 1 diabetes sufferers who receive early and intensive diabetes management may be able to cut their risk of impaired glomerular filtration rate (GFR), a kidney complication common to diabetics, by 50%.

"Our study shows that impaired GFR can be prevented in type 1 diabetes,” reported the study's lead author, Dr. Ian de Boer, an assistant professor of medicine at the University of Washington in Seattle. “This kidney complication that leads to end-stage renal disease doesn't have to happen." End-stage renal disease is the most severe kidney complication linked to diabetes.

As it can be very difficult for diabetics to manually regulate the perfect amount of insulin necessary for their bodies, many diabetics often develop complications and problems as a result of the autoimmune disease. For both type 1 and 2 diabetics, kidney disease is a very possible long-term complication, as de Boer explained that high blood sugar levels cause "cell level toxicity and death that results in the loss of the filtering units in the kidney that are replaced with scar tissue.”

De Boer and his colleagues reviewed and assessed data from two studies: the Diabetes Control and Complications Trial (DCCT) as well as the Epidemiology of Diabetes Interventions and Complications (EDIC) study.

The DCCT took place during the 1980s over the course of 6.5 years. When the study began, the average time since diagnosis of diabetes was roughly six years. The EDIC trial is an ongoing observational study that has followed 1,375 participants since the DCCT ended. This continuing study presently claims 16 years of follow-up data.

The DCCT researchers followed over 1,400 type 1 diabetics who were randomly given either intensive diabetes management or conventional diabetes therapy used in that decade. The individuals who received intensive diabetes management had the goal of lowering their A1C levels (HbA1C) to less than 6.05%.

HbA1C is a measurement of blood sugar levels that takes place over two to three months; levels below 6.05% are very close to levels of non-diabetic individuals. As such, decreased numbers of HbA1C usually equal decreased risk of severe complications.

According to de Boer, the patients involved in the DCCT who were in the intensive management group averaged an HbA1C of 7.3%, while the conventional group had an HbA1C average of 9.1%. Both groups in the EDIC reported HbA1Cs around 8%. Overall, the researchers discovered that only 24 people in the intensive therapy group developed an impaired GFR, in comparison to the 46 people receiving the conventional therapy. "That's a risk reduction of 50%," reported de Boer.

They also found that the risk of end-stage renal disease in the intensive therapy group was also reduced by 50%, as only eight diabetics in the intensive therapy group were at risk from it in comparison to the 16 people in the conventional therapy group. "Getting good glucose control up front in the disease course provides benefits immediately and in preventing complications for years to come," de Boer said. "The longer you're able to maintain good glucose control, the more benefit you're likely to derive."

"The good news is that even in the control group, the incidence of renal failure is much lower than we used to see, and there's a further 50 percent reduction in the intensive group," said Dr. Joel Zonszein, director of the Clinical Diabetes Center at the Montefiore Medical Center in New York City. "Very aggressive treatment early on can make a very big difference in renal function 20 years later," he continued.

The study findings are scheduled to be presented Saturday at the American Society of Nephrology's annual meeting in Philadelphia and published online simultaneously in the New England Journal of Medicine.