Diabetes is a well-established CHD risk factor known to double a person's chance of dying from heart disease. There has been much debate, but no large studies of whether diabetes carries different heart risks for women than for men, said Mark Woodward, Ph.D., professor of biostatistics at The George Institute for International Health at the University of Sydney, Australia.
Using data on more than 450,000 people, which included participants in the Asia Pacific Cohort Studies Collaboration, researchers found that men with diabetes had about 90 percent higher risk of dying from CHD as men without diabetes. Women with diabetes had more than two and a half times the risk of women without diabetes. That translates to a greater than 50 percent excess relative risk for women than for men, he said.
The data came from two previous meta-analyses of 16 studies and a collaborative overview of 44 studies in nine countries in the Asia-Pacific Region (China, Japan, South Korea, Taiwan, Hong Kong, Singapore, Thailand, New Zealand and Australia).
About 5 percent of all the participants had diabetes. Diabetes was defined according to self-reported history with or without fasting glucose evidence as an alternative. The researchers were able to adjust for age, systolic blood pressure, total cholesterol and cigarette smoking in most of the data sets, he said.
Perhaps better monitoring and control of blood glucose levels in women with diabetes would reduce their CHD risk compared with men with diabetes, Woodward said.
"There is some evidence to suggest that people with diabetes benefit from treatment with aspirin, cholesterol-lowering drugs and blood pressure-lowering agents," he said.
This meta-analysis has similar drawbacks to most overviews including the possibility of publication bias (in this case the exclusion of studies that did not report sex-specific results), misdiagnosis of diabetes, lack of information on an individuals' medical treatment, no information on menopause status or on whether subjects had Type 1 diabetes, due to the body's inability to produce insulin, or Type 2 diabetes, initially caused by the inability to use the insulin produced. Data from randomized trials of individuals with diabetes would clarify these issues.
Besides continuing to seek data on the sex-specific relative risk for CHD related to diabetes, researchers at the George Institute are leading a large scale randomized trial Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE) on 11,140 people. They are trying to ascertain whether more intensive glucose control combined with blood pressure lowering reduces cardiovascular mortality in people with Type 2 diabetes. The trial, which will follow participants for 4 ½ years on average, will end in 2006.
The conference is jointly sponsored by the American Heart Association, the Centers for Disease Control and Prevention, the American College of Cardiology Foundation, the World Heart Federation, the National Heart, Lung, and Blood Institute, and the Heart and Stroke Foundation of Canada.
This abstract was published in the February 2005 issue of Circulation: Journal of the American Heart Association.
Co-authors are: Federica Barzi and Rachel Huxley.
Statements and conclusions of study authors that are published in the American Heart Association scientific journals are solely those of the study authors and do not necessarily reflect association policy or position. The American Heart Association makes no representation or warranty as to their accuracy or reliability.
Abstract P155
NR05-1020 (IWC05/Woodward)
Presentation time is Friday, Feb. 18, 5:30 p.m. CST