Type 2 diabetes is not a CHD risk equivalent
MedWire News: Type 2 diabetes is not a coronary heart disease (CHD) equivalent, suggest findings from an Austrian study presented at the European Association for the Study of Diabetes 46th annual meeting in Stockholm, Sweden.
Guidelines currently suggest that diabetes is a CHD risk equivalent, but there is little evidence to confirm this. Information on baseline CAD status among diabetics is missing from many studies, despite the fact that it is likely to have a significant influence on the degree of cardiovascular (CV) risk experienced, said Heinz Drexel (Vorarlberg Institute for Vascular Investigation and Treatment, Feldkirch, Austria), who presented the data.
To address this and clarify CHD risk in Type 2 diabetics, Drexel and team carried out a study in 750 Austrian individuals, aged 63 years on average, who consecutively underwent angiography for suspected coronary artery disease (CAD). Of these, 164 (21.9%) had Type 2 diabetes. The patients were followed up for 8 years for incident CV events - CV death, nonfatal stroke or myocardial infarction, or revascularization.
The group had a high level of CV risk factors, including hypertension (52%), smoking (58%), and high total cholesterol (mean, 218.0 mg/dl or 5.6 mmol/l).
Testing revealed that 244 patients did not have significant CAD (coronary stenoses of 50% or more) or Type 2 diabetes, 50 had diabetes but no CAD, 342 had significant CAD but no diabetes, and 114 had both CAD and diabetes.
Drexel and team found that the CV event rates for patients with no CAD or diabetes and those with diabetes but no CAD were 20.5% and 22.0%, respectively, representing a non-significant difference between these groups.
Patients with diabetes and CAD, however, did have a substantially higher CV event rate than those with CAD but no diabetes, at 53.5% versus 39.5%. This translated into a significant difference in CV event rate between diabetic patients with and without CAD.
Drexel suggested that the reason why patients with diabetes are thought to have similar CV risk to CAD patients could be that, "if you take a mean of the risk experienced by diabetic patients with CAD and those without, they appear to have a similar risk to those with CAD alone."
Drexel said: "As long as the development of significant CAD can be prevented, Type 2 diabetes mellitus carried a much better prognosis than previously estimated"
He concluded: "Apart from its clinical and economical consequences, this is good news with important psychological implications for a considerable proportion of diabetic patients."
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By Helen Albert