ACCORD and A1C   (February 7, 2008)

The NIH recently announced that it has been decided to stop one part of a major North American clinical trial of diabetes and cardiovascular disease called ACCORD (an acronym for "Action to Control Cardiovascular Risk in Diabetes"). The announcement is available on-line [reproduced at For Safety, NHLBI Changes Intensive Blood Sugar Treatment Strategy in Clinical Trial of Diabetes and Cardiovascular Disease].

In the ACCORD study, adults who had type 2 diabetes and who were considered to be at high risk for heart attack or stroke were studied. The study looked at patients had two or more risk factors for heart disease in addition to diabetes, or who had been diagnosed with heart disease previously. The study was designed to look at blood glucose control, blood pressure control, and lipid levels.

The patients were randomized to receive either "intensive" lowering of blood glucose levels -- to below current recommendations (to an A1C of less than 6), or a less-intensive "standard" treatment strategy (aiming for an A1C of 7.0-7.9). An independent advisory group of experts had been set up to routinely review data from the trial, and they recommended stopping one treatment arm 18 months early due to safety concerns after review of available data, although the study itself will continue. The treatment that was stopped was the intensive glucose treatment group.

The study had enrolled 10,251 participants between the ages of 40 and 82. Of these, 257 in the intensive treatment group have died, compared with 203 within the standard treatment group. This is a difference of 54 deaths, or 3 per 1,000 participants each year, over an average of almost four years of treatment. Extensive analyses by ACCORD researchers have not determined a specific cause for the increased deaths among the intensive treatment group. Based on analyses conducted to date, it was reported that there is no evidence that any medication or combination of medications was responsible (that is, it wasn't rosiglitazone - the press release specifically mentions that this was closely looked at!).

"A thorough review of the data shows that the medical treatment strategy of intensively reducing blood sugar below current clinical guidelines causes harm in these especially high-risk patients with type 2 diabetes," said Elizabeth G. Nabel, M.D., director of the NHLBI. "Though we have stopped this part of the trial, we will continue to care for these participants, who now will receive the less-intensive standard treatment. In addition, we will continue to monitor the health of all participants, seek the underlying causes for this finding, and carry on with other important research within ACCORD."

This surprising finding has generated an extremely lively discussion amongst endocrinologists: were the problems in the intensive group actually due to hypoglycemia, and if not, to what? And what should we endocrinologists recommend to our patients? It is also unclear whether the results from ACCORD apply to patients who have been recently diagnosed with type 2 diabetes, or those whose cardiovascular risk is lower than the participants in this study. And it may not apply at all to people with type 1 diabetes, who were not studied in ACCORD.

My advice, based on what I've seen to date:

1) All patients on super-tight-control diabetes programs (especially type 2 patients) where A1C is being forced below 6.0 should be reassessed for cardiovascular disease by their physicians. And if there's evidence of heart or blood vessel disease, and/or hypertension and/or hyperlipidemia, the level of control might be loosened to allow the A1C to float up to 7.0 or perhaps slightly higher. And if not already on aspirin and other preventative tools for cardiovascular disease (such as smoking cessation), such tools should probably be started.

2) All patients with type 2 diabetes and A1C below 6.0 and known heart or other cardiovascular disease should have their diabetes program rechecked -- and if they are prone to hypoglycemia, the level of control should probably be loosened to allow the A1C to float up to 7.0 or higher. And maybe even if not prone to hypoglycemia, the control should be loosened.

3) And anyone with diabetes whose A1C is still 8.0 or above should continue to work to lower the A1C to the range of 7.0-7.9, and perhaps lower, and should be under the care and close supervision of a highly-skilled diabetes team. After all, it's very clear that blood sugar control reduces complications resulting from diabetes including eye, kidney, and nervous system diseases in people with both type 1 and type 2 diabetes.