The American College of Cardiology (ACC), American Diabetes Association (ADA), and American Heart Association (AHA) issued a joint statement urging clinicians not to abandon the groups’ generally recommended hemoglobin A1c (HbA1c) target of <7% for people with diabetes, despite findings from large studies that question the value of tight glycemic control (Diabetes Care. 2009;32:187-192). The statement coincided with another report that cast doubt on the effectiveness of intensive glucose control in reducing complications in people with poorly controlled type 2 diabetes (N Engl J Med. 2009;360:129-139).
The second study detailed findings by investigators involved in the Veterans Affairs Diabetes Trial (VADT). The team evaluated outcomes in 1,791 veterans (mean age, 60.4) with poorly controlled type 2 diabetes (diagnosed 11.5 years earlier on average) who had undergone either intensive or standard glucose control therapy. A median 5.6 years of follow-up uncovered no significant differences in retinopathy, major nephropathy, or neuropathy in the intensive-control group when HbA1c was driven down from 8.4% to 6.9%. Like the earlier results from the ADVANCE and ACCORD studies, this arm of the VADT showed that intensive therapy did not reduce cardiovascular events in type 2 patients.
The position statement from the ACC, ADA, and AHA provided several possible explanations for the results, and the organizations continue to champion a general HbA1c target of <7%. However, they noted that providers might suggest more individualized HbA1c targets for two particular types of patients: a goal even lower than <7% for individuals who have been recently diagnosed with diabetes, have a long life expectancy, and have no significant cardiovascular disease; and a goal less stringent than <7% for those with a history of severe hypoglycemia, limited life expectancy, advanced microvascular or macrovascular complications, extensive comorbid conditions, or long-standing diabetes they find difficult to control.
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