Diabetes Confers Earlier Heart Risk

June 29, 2006 -- Diabetes is a big risk factor for heart disease and stroke, and now new research helps quantify that risk.

A Canadian study found that, in general, people with diabetes have a risk for heart disease (such as heart attack), stroke, and death from any cause similar to someone more than a decade older but without the disease.

Those with diabetes tended to be 15 years younger than people without diabetes when they developed risk factors putting them at high risk for heart attacks and strokes.

For men with diabetes, the average age for the transition from moderate to high risk was 48. For women it was 54.

These findings are reported in the July 1 issue of the journal The Lancet.

As with people without diabetes, age was still a very important predictor of cardiovascular risk for those with diabetes. Those 40 and older tended to have a much greater risk than younger people with the disease.

"A 70-year-old with diabetes is generally going to have a higher risk than someone who is 40. And under age 40, on average, people were not at high risk," says Gillian L. Booth, MD, one of the researchers involved in the study.

Heart Attack, Stroke Risk High

Diabetes patients may also have additional risk factors for heart disease and stroke, such as obesity, high blood pressure, or abnormal cholesterol levels. As a result, more than 65% of people with diabetes end up dying from heart disease and strokes, according to the American Diabetes Association.

Because this risk is so great, aggressive treatment to lower the risk has become a mainstay of diabetes therapy in recent years.

In an effort to better understand the importance of age in heart and stroke risk among people with diabetes, Booth and colleagues from Toronto's Institute for Clinical Evaluative Sciences (ICES) conducted a population-based study looking at 379,000 people with diabetes and 9 million people without the disease. All were living in Ontario, Canada.

They used the Ontario Diabetes Database to determine whether or not someone had diabetes, but the researchers were unable to distinguish between type 1 and type 2 diabetes.

Aggressive Treatment Needed?

Type 1 diabetes is much less common, occurring in only 5% to 10% of diabetes cases in the U.S. It often first develops in children and young adults. But the majority of cases are from type 2 diabetes, which is associated with age and being overweight or obese.

The Canadian researchers found that middle-aged and older people with diabetes tended to have a high risk for heart attacks and strokes, while the risk for people under age 40 was less well defined.

Booth says the findings make it clear that most diabetes patients 40 and older would benefit from aggressive treatment to lower blood pressure and normalize blood sugar and cholesterol levels.

"At least in the short term, many people with diabetes who are younger than 40 seem to have a low to moderate absolute risk of cardiovascular disease," she says.