Jan. 29, 2003 - The most serious complications of type 2 diabetes -- heart disease, kidney failure, nerve damage, and blindness -- may be slashed by as much as half by combining often-recommended lifestyle habits with a specific drug regimen when compared with usual care, suggests a new study.
This combination program, developed at the University of Copenhagen and tested for eight years in 160 diabetics facing the highest risk of heart disease and other diabetes-related complications, is unveiled in today's issue of TheNew England Journal of Medicine. It incorporates a "heart-smart" diet, moderate exercise, and the daily intake of several vitamins, aspirin, and pharmaceuticals currently used by millions to lower blood pressure and cholesterol -- all strategies that have long been advocated for reducing risks of heart disease.
"While these approaches are widely recommended, we think it's the additive effects of combining all these methods that produced such dramatic results," says study author Oluf Pedersen, MD, DMSCi, of the university's Steno Diabetes Center. "A 50% relative reduction in cardiovascular disease disorders has never been shown before in type 2 diabetics -- let alone those at the highest risk of these problems."
His study involved diabetics who already had early signs of kidney damage -- a condition called microalbuminuria characterized by the presence of tiny amounts of protein in the urine. Diabetics with microalbuminuria are at a very high risk for heart disease. "Eventually, this condition affects one in three type 2 diabetics, placing them at even greater risk of cardiovascular disease and other diabetes-related complications," Pedersen tells WebMD.
Even without this complication, type 2 diabetics die from heart disease three times more frequently in the U.S. than do non-diabetics and have a life expectancy five to 10 years less than the typical American -- largely because of their increased risk of heart disease and stroke.
"In many ways, it's even more important for those with diabetes to deal with the cardiovascular risks that result from diabetes than to focus on glucose control itself," says Douglas Morris, MD, professor of medicine and director of the Heart Center at Emory University School of Medicine. "Whether it's high cholesterol, hypertension, smoking ... the bad effects of every risk factor is accentuated in people with diabetes. And like other people, many diabetics have multiple cardiovascular risk factors."
Half the study participants followed Pedersen's combination program for eight years, which tackles several risk factors -- including overweight, high cholesterol, high blood pressure, and smoking -- and includes:
- A diet that includes at least six servings of vegetables and one serving of omega-3 rich fish such as herring, salmon, or mackerel each day. No more than 30% of total calories can come from fat, with no more than 10% from saturated fats, which can increase "bad" LDL cholesterol. With the exception of daily fish consumption, this is similar to the standard low-fat "heart-healthy" diet recommended by doctors.
- At least 30 minutes of light to moderate exercise, three to five times a week, which is actually less than the recommendations of some experts who advocate an hour of exercise each day.
- Quitting smoking if they used tobacco
- Consuming the equivalent of a half-aspirin, along with supplements of 250 mg of vitamin C, 100 mg of vitamin E, 400 micrograms of folic acid, and 100 micrograms of chromium picolate daily. "However, I don't much emphasis on any vitamin except folic acid," says Pedersen. "Since we started our trial, there is new evidence that C and E have no impact on reducing risks." Chromium was thought to help stabilize blood sugar levels, but studies have produced mixed results.
- Taking 50 mg of eitherCapoten or Cozaar to lower blood pressure; some patients also received Lipitor, which lowers the "bad" LDL cholesterol and can also lower triglycerides, and may increase "good" HDL cholesterol.
The other participants followed the conventional recommendations by the Danish Medical Association (which have since been revised) which included the same exercise and not smoking regimen, along with a diet getting up to 35% of all calories from fat, three daily servings of vegetables, and fish once a week. They did not receive the drugs.
In addition to nearly half the rate of death from cardiovascular disease, kidney failure, and blindness resulting from diabetes-induced blood vessel problems, 70% of combination therapy participants achieved "low-risk" cholesterol levels, 60% reached ideal triglycerides levels, and more than half achieved good control of their blood pressure.. By comparison, fewer than half of those using the conventional approach met these goals.
"I'm not surprised by this finding; I'm elated by it," American Diabetes Association president Francine Kaufman, MD, tells WebMD. "This is validation to the position we had held -- treat a multiplicity of risks factors associated with diabetes as intensively as possible. It's not enough to just know your blood glucose, cholesterol, and blood pressure levels. You need to take action and do something about those risk factors."