TUESDAY, Oct. 11, 2005 (HealthDay News) -- A new study offers good news for people with type 1 diabetes: Their incidence of serious kidney disease is much lower than was previously believed.
And the risk of dying from type 1 disease during the first 20 to 30 years after diagnosis has decreased by half, Finnish researchers report.
Past estimates predicted that one in five people with type 1 diabetes would develop end-stage renal disease (ESRD) at some point during the 20 years following diagnosis. The new study found that number is actually closer to one in 50 after 20 years and about one in 12 after 30 years of living with the disease.
"The risk of developing ESRD has dropped by more than half since 1965 to 1969," said study author Dr. Patrik Finne, administrative director of the Finnish Registry for Kidney Diseases, and a senior researcher at the University of Helsinki.
"The study also showed that type 1 diabetic patients' risk of dying during the first 20 to 30 years after diagnosis of diabetes has dropped by more than 50 percent since 1965 to 1969," said Finne.
Results of the study appear in the Oct. 12 issue of the Journal of the American Medical Association.
Diabetic nephropathy -- kidney damage caused by diabetes -- is a common complication of the disease, according to the National Library of Medicine. It usually occurs when blood sugar levels are poorly controlled. Diabetic nephropathy can progress to end-stage renal disease, which is treated with either kidney dialysis or a transplant.
According to Finne and his colleagues, no large population-based studies had been done to truly assess the incidence of ESRD in people with diabetes, which is why they reviewed the records of more than 20,000 Finns diagnosed with type 1 diabetes between 1965 and 1969.
All were under 30 at the time of their diagnosis, and part of the Finnish Diabetes Register. This register contains information on nearly 100 percent of people with diabetes in Finland.
Insulin treatment is provided free of charge to diabetics in Finland, according to the study.
The researchers followed everyone in the group until they developed ESRD, died, or until the end of the study period -- Dec. 31, 2001.
While previous estimates placed the risk of ESRD at 20 percent after 20 years of diabetes, this study found the rate was only 2.2 percent after 20 years. After 30 years, the study found the rate of ESRD was 7.8 percent.
And the risk of death dropped by 59 percent from the start of the study, between 1965 to 1969, to near the end, 1980 to 1999. Overall, 6.8 percent of the people died during the first 20 years, and 15 percent died sometime during the 30 years following their diagnosis. Most of the deaths occurred in people who had not developed ESRD, according to the study.
Finne said this study didn't look at the reasons for the reduction in deaths and kidney disease, but said that "the treatment of type 1 diabetes has developed considerably since 1965. For example, for more than 20 years, patients have been able to measure blood glucose at home and adjust the insulin dose according to these measurements."
He added that newer insulins have been developed, as have better medications for treating high blood pressure, a risk factor for kidney damage.
In type 1 diabetes, the body does not produce the hormone insulin, which is needed to convert sugar in the blood into energy for cells. So people with the disease must typically give themselves injections of insulin.
Dr. Stuart Weiss, an endocrinologist at New York University Medical Center, said, "This study's results are in keeping with my suspicion that type 1 diabetes is becoming less of a horrible disease for those who do the right thing."
But, Weiss added, while the study's results are promising and appear to reflect what he sees in his own practice, they should be interpreted with caution in the United States.
"It's hard to extrapolate this data for a U.S. population because the population is fairly uniform in Finland, and everyone is covered by the government, so it doesn't cost as much for patients to maintain good control as it does for people without insurance in this country," said Weiss.
Both Weiss and Finne said that people with diabetes need to know that keeping blood-sugar levels under control reduces the risk of complications, such as ESRD.
"Maintaining good control of glucose and hypertension [high blood pressure] limits morbidity and mortality," said Weiss.
More information
To learn more about controlling your blood sugar levels, read this article from the American Diabetes Association.
