ANN ARBOR--- People who develop type 2 diabetes at an early age can substantially reduce their rates of blindness and kidney failure in later life by tightly controlling their blood-sugar level, according to researchers at the University of Michigan Medical Center and the Veterans Administration Medical Center in Ann Arbor.
Those who get diabetes later in life, however, may gain only small benefits from tight control and may well choose not to undergo the difficult treatment regimens needed to achieve it.
The research findings will be published in the Nov. 1 issue of the Annals of Internal Medicine.
Approximately nine out of 10 diabetics have type 2 diabetes, which means their pancreases produce some insulin, but not enough to meet their needs.
Previous research demonstrated that intensive medical treatment has substantial benefits for people with type 1 diabetes---so called "juvenile-onset" diabetes---but the value of tight control of blood-sugar in type 2 diabetics has been more controversial.
In the United States, about 8 million people are diagnosed with diabetes, which is the No. 1 cause of blindness, renal failure and amputation in industrialized nations.
The research suggests how those devastating complications might be reduced.
People who develop type 2 diabetes at a relatively early age---before age 50 to 55, for example---are at far greater risk of ultimately losing their vision and kidney function than those whom the disease strikes later. If people with early onset of type 2 diabetes can maintain a near-normal blood-sugar level, however, their lifetime risk of diabetes-related blindness will be significantly decreased, the researchers found.
"We need to devote more attention to this high-risk group," said Rodney Hayward, M.D., associate professor of medicine and public health at the U-M Medical Center and director of the Center for Practice Management & Outcomes Research at the VA Medical Center in Ann Arbor. "Much of the high cost of diabetes---in both human suffering and dollars and cents---is due to complications which could have been prevented early on."
For patients in one health maintenance organization the researchers studied, in fact, intensified medical care for less than 20 percent of all diabetics---those at the highest risk---could eliminate more than 80 percent of the preventable blindness.
"It is important to note, however, that about half of diabetics get diabetes after age 60, and they are generally at low risk of complications if they maintain moderate blood sugar control," said Sandeep Vijan, M.D., the lead investigator on the project and an Agency for Health Care Policy & Research fellow at the time the research was conducted. Although strict blood sugar control would further reduce risk for those with late-onset diabetes, the benefits would be small---generally decreasing the risk of complications by less than one in 100.
In addition, Vijan said, it often is difficult to achieve strict blood sugar control. "Several new medications can help most type 2 diabetics maintain moderate control of their blood-sugar level without the use of insulin," he said. "However, high-risk patients, those who require tight blood sugar control to reduce future health complications, often will need insulin therapy and closer monitoring and more medical attention than most diabetics typically receive today."
That, the researchers point out, creates a policy issue for the government and insurance companies.
The research was supported by the Department of Veterans Affairs and the Agency for Health Care Policy & Research. Vijan and Hayward conducted the research with Timothy Hofer, M.D.