In the July 2004 issue of Diabetes Care, Brown et al. (1) conclude by stating, “our results strongly suggest that the recommended [HbA1c] threshold for [treatment] action should be 7.0% or lower” and “an even stronger signal would be provided by a treatment threshold of 6.0%, which has proved widely achievable in the test phase of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study.”
We would like to point out that the ACCORD Vanguard (“test phase”) results have not been published or presented and are not available in the citation given. (Brown et al. referenced a URL [http://apps.nhlbi.nih.gov/clinicaltrials/background.asp] that cannot be directly reached but can be accessed via http://apps.nhlbi.nih.gov/clinicaltrials/, selecting “Diabetes Mellitus,” clicking on “submit,” clicking on the ACCORD trial, and then clicking on “background.”) More importantly, however, Brown et al. fail to acknowledge that treatment targeting HbA1c <6.0% (or, in the authors’ words, a “treatment threshold of 6.0%”) has not been proven to improve health outcomes, either microvascular or macrovascular. Not only is such a treatment strategy extremely difficult, but there are potential adverse consequences, such as hypoglycemia and drug-specific side effects. There is currently no sound basis to recommend such targets in clinical practice.
The ACCORD trial is designed to determine whether a therapeutic strategy that targets HbA1c <6.0% reduces cardiovascular disease events in type 2 diabetes. Microvascular events are a secondary outcome. Results from ACCORD and other pending studies are needed to inform clinical practice on this issue.
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H.C.G. has received a research grant from Aventis.