Newly diagnosed and young adults with diabetes at greater risk for stroke

Risk of stroke higher in blacks before age 45 among patients with diabetes.

Diabetes is a leading risk factor for stroke, especially among newly diagnosed adults with type 2 diabetes and adults with diabetes aged 55 or younger, according to two studies presented at the American Stroke Association’s International Stroke Conference 2006, Kissimmee, Fla.

One study, conducted by Canadian researchers, found that patients newly diagnosed with type 2 diabetes have double the rate of stroke of the general population.

“One would think that the consequences of diabetes would occur over a long period, but we found that new-onset diabetics have double the rate of stroke in the first five years after diagnosis as the general population,” said Thomas Jeerakathil, MD, an investigator on the study and assistant professor of medicine and neurology at the University of Alberta in Edmonton, Canada.

“The finding suggests some of the cardiovascular effects of diabetes are already established at the time of diagnosis and aggressive prevention is justified in this patient group,” he said in a press release.

Studies have shown that having type 2 diabetes is associated with a higher risk for stroke and CVD, but most studies have focused on people who have had diabetes for years. Researchers have also known that while patients with diabetes tend to focus on blood glucose control, they don’t tend to have optimum control of blood pressure.

To examine the short-term risk for stroke in patients with newly diagnosed diabetes, Jeerakathil and colleagues analyzed a database of people in the provinces of Saskatchewan, Canada. They identified 12,272 people (average age 64) who had new prescriptions for diabetes medications between 1991 and 1996, and followed them for about five years.

More than 9% were admitted to the hospital for stroke; about one-fifth died. Researchers compared stroke rates to a similar-aged group in the general population.

“Our findings suggest that, particularly if people have a new diagnosis of diabetes, they should have all their cardiovascular risk factors managed optimally,” Jeerakathil said.

Age as a risk factor

In a separate study, American researchers reported that diabetes increased stroke risk most before age 55 and in blacks.

“If you look across the age spectrum, diabetes increases the risk for stroke by about threefold,” said investigator Brett Kissela, MD, associate professor in the department of neurology at the University of Cincinnati in Ohio.

“But our study suggests that a lot of that risk is front-loaded. It’s a bigger risk for younger than older people, and probably higher for blacks than for whites,” Kissela said in a press release.

Kissela and colleagues analyzed an existing database of people living in five counties in the Greater Cincinnati area. They compared the incidence rate of stroke in those patients with type 2 diabetes to those without.

They found that 2,432 strokes occurred in the Cincinnati metropolitan region in 1999, and 33% of patients were diagnosed with diabetes before their stroke occurred. The average age for stroke was 70 years for the patients with diabetes vs. 73 years for those without diabetes.

The researchers also reported that 25% of the patients with diabetes who had a stroke were black vs. 15% of the patients without diabetes who had stroke.

The greatest risk for stroke was in patients younger than 55 in both races; however, blacks had a seven- to ninefold increased risk for stroke before age 45 among those who have diabetes vs. those who do not. Among whites, their increased risk ranged between six- and 17-fold for those under age 55.

For more information:

• Jeerakathil T, Johnson J, Simpson S, et al. Stroke risk in newly diagnosed diabetics. #115. Presented at the American Stroke Association’s International Stroke Conference 2006. Feb. 16-18, 2006. Kissimmee, Fla.
• Kissela B, Alwell K, Hornung R, et al. Effect of diabetes on the incidence of ischemic stroke. #356. Presented at the American Stroke Association’s International Stroke Conference 2006. Feb. 16-18, 2006. Kissimmee, Fla.