DALLAS, Jan. 17 – People with insulin-dependent (type-1) diabetes have an increased risk of dying from a stroke, according to first-time findings from a large, community-based study reported in today’s rapid access issue of Stroke: Journal of the American Heart Association.
Cardiovascular disease is already recognized as the main cause of long-term complications and death in patients with diabetes. The likelihood of death from cerebrovascular disease – related to the blood supply in the brain and the No. 1 cause of stroke – has not been previously reported for patients with type-1 diabetes. Previous studies have shown that cerebrovascular death rates are raised in patients with type-2 diabetes (non–insulin-dependent diabetes).
“The results from this group of patients with type-1 diabetes show that at all ages death from cerebrovascular disease is higher in the patients with diabetes than in the general population,” says lead author Susan P. Laing, Ph.D., of the Institute of Cancer Research in Surrey, United Kingdom.
Furthermore, she notes that the risk of stroke relative to the general population was the greatest for the 20–39 age groups, in part reflecting the very low death rate from cerebrovascular disease at this age. “These observations emphasize the vital need to identify and treat known cardiovascular risk factors in young people with diabetes,” she says.
The study, called the Diabetes UK Cohort, included 23,751 patients diagnosed with type-1 diabetes under age 30. It recorded cerebrovascular death rates by age and gender. Researchers followed patients for an average of 17 years. Then they compared standardized mortality ratios – a calculation of the number of observed deaths in the study group compared to the number of expected deaths from cerebrovascular disease in the general population.
There were 1,437 deaths – 80 due to cerebrovascular disease. Cerebrovascular disease constituted 4 percent of all deaths under the age of 40 and 8 percent over age 40. Overall, the rates were significantly higher compared with the general population.
In the 20–39 age group, the risk of cerebrovascular death was increased more than five-fold in men and seven-fold in women compared to the general population.
Co-authors are Anthony J. Swerdlow, D.M.; Lucy M. Carpenter, Ph.D.; Stefan D. Slater, M.D.; Andrew C. Burden, M.D.; Johannes L. Botha; Andrew D. Morris, M.D.; Norman R. Waugh; Wendy Gatling; Edwin A.M. Gale; Christopher C. Patterson, Ph.D.; Zongkai Qiao, M.Sc.; and Harry Keen, M.D.