Major Long-Term Benefits of Intensive Therapy for Type 1 Diabetes: Study Reports Near-Normal Glucose Levels Lead to Large Reductions in Kidney, Heart, Severe Eye Diseases and Stroke
June 22, 2013
Long-term, intensive therapy for people with type 1 diabetes helps them achieve near-normal glucose levels and substantially reduces the risk of developing severe eye disease, impaired kidney function, heart disease and stroke. These findings are the latest results from a landmark government-sponsored study, reported at a special symposium held at the American Diabetes Association’s 73rd Scientific Sessions® today.
Investigators from the National Institutes of Health-funded Diabetes Control and Complications Trial (DCCT), and its long-term follow-up study, the Epidemiology of Diabetes Interventions and Complications (EDIC), presented an overview and new results of this landmark study at the special symposium, 30 years after its initial launch.
The DCCT, which began in 1983, demonstrated a consistent beneficial effect of intensive therapy aimed at achieving near-normal glucose levels on reducing complications, compared with conventional therapy. Improved glucose control was achieved with frequent insulin injections or insulin pump therapy guided by frequent self-monitoring of blood glucose with fingerstick testing.
As first reported in 1993, intensive therapy reduced the early stages of eye, kidney and nerve complications by as much as 76 percent compared with the conventional therapy.
"On the basis of these results, DCCT intensive therapy has been adopted worldwide as the standard of therapy for type 1 diabetes," said David M. Nathan, MD, director of the Massachusetts General Hospital Diabetes Center in Boston. Dr. Nathan co-chairs the study. While the initial DCCT results were dramatic, the effect of intensive therapy in reducing the longer-term consequences of these complications, including kidney failure, loss of vision, amputations and heart disease, were unknown. Long-term follow-up of the DCCT has been conducted over the past 20 years to answer these questions and the new data continue to show positive results. More than 95 percent of the surviving members of the original 1,441 DCCT research participants continue to be followed.
At the symposium, the DCCT/EDIC investigators reported the results of the long-term follow-up of the study population:
The long-term consequences of intensive therapy have shown a 50 percent reduction in risk for developing impaired kidney function, reported Ian deBoer, MD, a DCCT/EDIC investigator from the University of Washington in Seattle. "The reduction in impaired kidney function represents a major finding since kidney failure increases the risk of subsequent heart disease and death more than any other complications."
Heart Disease and Stroke
Cardiovascular disease, including heart disease and stroke, is the major cause of early death in diabetes. John Lachin, MD, the principal investigator of the DCCT/EDIC Coordinating Center at The George Washington University, in Washington, D.C., reported that intensive therapy reduced heart disease and stroke by almost 60 percent.
"The reductions in heart attacks and strokes should translate over time into reduced early death," he said.
Lloyd Aiello, MD, a DCCT/EDIC investigator at the Joslin Diabetes Center in Lanham, Md., reported that intensive therapy reduced the severe, vision-threatening stages of diabetic eye disease and the need for ocular surgery and procedures by 50 percent in the original intensive therapy group. "Although we have means of treating severe eye disease to prevent vision loss, it is always better to reduce its development in the first place in order to avoid the need for expensive and only partly effective late-stage therapies. Intensive diabetes therapy effectively accomplishes this goal," said Dr. Aiello.
Limited Hand and Shoulder Flexibility
Complications of diabetes cause more cases of blindness, kidney failure and amputations than any other disease in the nation. In addition to studying these common complications, the DCCT/EDIC investigators reported on progressive stiffening around the hands and shoulders that affected two-thirds of DCCT participants after 30 years of diabetes. Although this complication is common and may adversely affect the ability to carry out daily activities, it is under-appreciated compared to the other complications.
"Lower glucose level was associated with reduced risk of these complications as it is for the other better recognized complications," said Mary Larkin, RN, a DCCT/EDIC investigator at Massachusetts General Hospital in Boston.
The DCCT/EDIC investigators emphasized that the overall study results indicate the importance of implementing intensive therapy as early as possible in the course of type 1 diabetes. The effort, expense and increased risk for hypoglycemia that accompany intensive therapy pay off in the long run with a substantially reduced risk of developing serious eye and kidney disease, heart disease and stroke. "The DCCT/EDIC has given new hope to people with type 1 diabetes," said Dr. Nathan.
Judith Fradkin, MD, director of the Division of Diabetes, Endocrinology and Metabolic Diseases of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), agreed. "The long-term results of the DCCT/EDIC further reinforce the importance of early intensive therapy over the lifetime of people with type 1 diabetes," Dr. Fradkin said. "Our challenge now is to ensure that all patients with type 1 diabetes are able to take advantage of these remarkable findings and to make intensive therapy as convenient and safe as possible."
The NIH has supported the DCCT/EDIC over the past 30 years under grants U01DK094176 and U01DK094157. The DCCT is registered as NCT00360815and EDIC is registered as NCT00360893 in clinicaltrials.gov.
About the American Diabetes Association
Nearly half of American adults have diabetes or prediabetes; more than 30 million adults and children have diabetes; and every 21 seconds, another individual is diagnosed with diabetes in the U.S. Founded in 1940, the American Diabetes Association (ADA) is the nation’s leading voluntary health organization whose mission is to prevent and cure diabetes, and to improve the lives of all people affected by diabetes. The ADA drives discovery by funding research to treat, manage and prevent all types of diabetes, as well as to search for cures; raises voice to the urgency of the diabetes epidemic; and works to safeguard policies and programs that protect people with diabetes. In addition, the ADA supports people living with diabetes, those at risk of developing diabetes, and the health care professionals who serve them through information and programs that can improve health outcomes and quality of life. For more information, please call the ADA at 1-800-DIABETES (1-800-342-2383) or visit diabetes.org. Information from both of these sources is available in English and Spanish. Find us on Facebook (American Diabetes Association), Twitter (@AmDiabetesAssn) and Instagram (@AmDiabetesAssn)