Further to CVD in diabetes

Issue: BCMJ, Vol. 48, No. 5, June 2006, page(s) 209-210 Letters
Andrew Farquhar, MD, Jiri Frohlich, MD, FRCPC, Andrew Ignaszewski, MD, FRCPC, David Wood MD, FRCPC

I would like to make a few points in relation to Drs Frohlich and Ignaszewski’s response to my letter on CVD in diabetes (BCMJ 2006;48[1]:10-12).

I suggested that the “vast majority of” (not “all”) diabetics would benefit from an earlier and more aggressive pharmacological intervention. They emphasize the metabolic syndrome. In fact, up to 90% of type 2 diabetics have the metabolic syndrome and few would deny the benefit to these individuals of metformin, aspirin, and ACE inhibitor, and a statin.

Regardless of whether diabetes truly is a coronary risk equivalent, the evidence for it is good enough for not only the Canadian Diabetes Association, but also US, European, and UK guidelines to all recommend that people with type 2 diabetes be treated as if they already have vascular disease. The Canadian Dyslipidemia Guidelines, of which Dr Frohlich is a prominent author, also suggest that diabetes be treated as a coronary risk equivalent.

It is hardly surprising that such a gap exists between guideline recommendations and frontline practice when we continue to get mixed messages from the experts.

Finally, the authors raise the issue of cost-benefit from the use of these drugs yet suggest that all type 2 diabetics be screened with an ECG. Where is the evidence for the cost-benefit of that procedure?

—Andrew Farquhar, MB


The authors respond

Dr Farquhar makes a number of good points. We certainly agree that patients with diabetes who also have the risk factors of the metabolic syndrome (great majority of DM patients) should be treated to the high-risk targets.

In regard to the Canadian Diabetes Association guidelines for lipids,[1] there are currently two targets: LDL-C <2.5 mmol/L and TC/HDL-C ratio <4.0 for “most patients with diabetes” and LDL-C <3.5 mmol/L and TC/HDL-C ratio <5.0 for “younger patients with shorter duration of diabetes and no other complication of diabetes and no other risk factors for vascular disease.”

Dr Farquhar is right that the 2003 lipid recommendations[2] do not make the above distinction. However, in the draft of the 2006 guidelines the recommendations for the high-risk LDL-C and ratio targets will be for “most patients with DM” together with the suggestion to use apo B (<0.85 g/L) as an alternative treatment target (also mentioned in the CDA guidelines).

As discussed in our original article, the American College of Cardiology and the American Diabetes Association have developed guidelines for screening DM2 patients with ECGs.[3] We agree that there is not strong cost-benefit evidence for this procedure.

—Jiri Frohlich, MD, FRCPC
—Andrew Ignaszewski, MD, FRCPC
—David Wood MD, FRCPC



References Top

1. CDA 2003 clinical practice guidelines for the prevention and management of diabetes in Canada. Can J Diabetes 2003;27(suppl2):S1-S152. http://www.diabetes.ca/cpg2003/default.aspx 
2. Genest J, Frohlich J, Fodor G, McPherson R. Recommendations for the management of dyslipidemia and the prevention of cardiovascular disease: summary of the 2003 update. CMAJ 2003;169:921-924. PubMed Citation Full Text 
3. Consensus development conference on the diagnosis of coronary heart disease in people with diabetes. Diabetes Care 1998;21:1551-1569. PubMed Citation Full Text 


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