Diabetics who used insulin aggressively to control their blood sugar for 6-1/2 years cut their risk of heart attack, stroke or bypass surgery in half compared to those who did not, according to a new study.
The finding, published in Thursday's New England Journal of Medicine, adds to the list of health problems such as eye, nerve and kidney damage that can be prevented by careful glucose control in people with Type 1 diabetes, the less common form of the disease that usually strikes in young people.
"Much to our delight, it appears that this intensive therapy introduced years and years ago seems to have this long-term benefit on heart disease and stroke," author David Nathan of Massachusetts General Hospital told Reuters.
It shows that aggressive diabetes treatment "should begin as early as possible and be maintained as long as possible," said coauthor Saul Genuth of Case Western Reserve University.
About 7 percent of the U.S. population has some form of diabetes and about 75 percent of those will die from a heart attack or stroke. The rate among nondiabetic people is less than 50 percent, Nathan said.
The new discovery is an offshoot of a study begun in 1983 involving 1,441 people age 13 to 39 with Type 1 diabetes, which was once known as juvenile diabetes.
Half were given intensive treatment using an insulin pump or at least three insulin injections a day — combined with careful monitoring — for an average of 6-1/2 years. The remainder received conventional treatment of one or two shots daily.
Aggressive treatment embraced
After the researchers discovered that the intensive treatment reduced eye, kidney and nerve disease by about 75 percent, all of the volunteers were encouraged to embrace aggressive treatment.
Two years ago, researchers reported that volunteers in the original test group were less likely to develop atherosclerosis, often referred to as hardening of the arteries.
Now it is clear that aggressive diabetes control, even over a decade, reduces other heart and circulatory problems as well.
When Nathan's team tallied up the number in each group who had a heart attack, stroke, chest pain, or other problem requiring angioplasty or bypass surgery, they counted 52 people of the 589 in the conventional treatment group and just 31 among the 593 who practiced aggressive control.
Most of the patients who got conventional treatment had more than one serious health event, so the Nathan team calculated that aggressive treatment cut the risk of heart attack, stroke or death from any cardiovascular problem by 57 percent.
Specifically, 33 in the conventional treatment group had a heart attack, compared to 14 who got more insulin shots.
"The longer we follow patients, the more we're impressed by the lasting benefits of tight control," said Nathan.
Whether the findings will apply to Type 2 diabetes, which strikes older people and is often associated with obesity, "is literally the billion dollar question because there are an estimated 1.2 million new cases of Type 2 diabetes each and every year in the U.S., and that's larger than the entire Type 1 population," Nathan said.
Two large studies are under way to try to address that question, but ultimately, "all diabetics should use intensive therapy because we know it helps prevent eye, kidney and nerve disease," he said.