THURSDAY, Feb. 16, 2006 (HealthDay News) -- The increasing incidence of type 2 diabetes could bring a rise in death and disability caused by stroke, new research warns.
Stroke risk in people newly diagnosed with type 2 diabetes is double that of the general population, and those under age 55 are at greatest risk, according to two studies to be presented Thursday at the American Stroke Association's annual stroke conference, in Kissimmee, Fla.
One Canadian study of more than 12,000 newly diagnosed type 2 diabetics found that, "in the first five years, more than 9 percent were admitted to the hospital for stroke," according to lead researcher Dr. Thomas Jeerakathil, an assistant professor of neurology and medicine at the University of Alberta in Edmonton, Alberta.
What's not known, because it was beyond the scope of this study, is whether those who experienced stroke were even less likely to keep risk factors such as diabetes or blood pressure under control.
The new findings add much to what experts knew -- or didn't know -- about diabetes and its relation to stroke, Jeerakathil said.
"The usual thought is that complications don't develop for several years," he said. "We were interested in looking at the risk soon after diagnosis. Most of the studies that have looked at this in the past have looked at risk of stroke after five, 10 or more years."
His team used health records from the Canadian province of Saskatchewan to track the stroke incidence of more than 12,000 people with newly diagnosed type 2 diabetes.
The researchers found that the risk of stroke over a follow-up of about five years was double for the new diabetics vs. that of the general population.
The finding "argues for very aggressive cardiovascular risk factor control," Jeerakathil said. He advises diabetics to "pay attention to cholesterol and blood pressure, stop smoking, lead an active lifestyle and eat a diet high in whole grains and vegetables."
Right after a type 2 diabetes diagnosis, "I think people tend to think they can relax, that complications are far in the future," Jeerakathil said. "In fact, there is a real risk even in the first few years after being diagnosed of having a stroke."
The study did have its limitations, Jeerakathil noted. "We had to define 'new-onset' [diabetes] as those who got a new prescription for diabetes medication. The five years [follow-up] started when they got their first prescription, and the limitation is that some may have been diet-controlled [at first], and may have had the diagnosis longer than five years. But most people are started on medication soon after diagnosis," he said, so the limitation may not be significant.
In the second study, Dr. Brett Kissela, an associate professor of neurology at the University of Cincinnati, found that diabetes is one of the most important risk factors for stroke, and that the risk is greatest in patients under age 55.
"What we found is that risk is not uniform across all the different age groups," he said. "In fact, people who get diabetes at a younger age have a substantially increased risk of stroke."
His team evaluated more than 2,400 cases of strokes occurring in 1999 in the Cincinnati area, comparing the incidence of stroke in those with type 2 diabetes to those without. According to the researchers, 33 percent of the patients were diagnosed with diabetes before the stroke occurred.
Kissela's team broke down the cases by age and race.
They found that people under age 55 with type 2 diabetes had a risk of stroke that was five to nine times higher than that of similarly aged nondiabetics. And before age 45, black Americans with diabetes had a seven to nine times greater risk of stroke than those without diabetes of the same ages and race.
"Diabetes is an important risk factor for stroke across the life span, but it's very high for those who have been diagnosed at a young age," Kissela concluded.
Dr. John Buse, vice president of the American Diabetes Association, welcomed both studies. He pointed out that there's been a paucity of research focused on diabetes and stroke risk alone, rather than all types of cardiovascular disease.
The findings should help get the message out that those with diabetes need to pay close attention to cardiovascular risk factors, he added.
"The American Diabetes Association did a survey a few years ago of people with diabetes," Buse said. "Even though 80 percent of people with diabetes eventually die of heart disease or stroke, most patients with diabetes, about 70 percent, said they did not feel at risk of heart disease or stroke."
Learn more about preventing type 2 diabetes at the American Diabetes Association.