‘Our study provides no support for the view that rapid lowering of A1C caused the excess mortality,’ said lead researcher Dr. Matthew Riddle, Professor of Medicine, Oregon Health & Science University. ‘The data are not compatible with that interpretation.’
The ACCORD glucose control clinical trial was designed to investigate whether an intensive strategy seeking A1C levels below 6 percent would reduce the risk of cardiovascular disease in people with type 2 diabetes at especially high risk of cardiovascular disease. More than 10,000 participants were randomly assigned to either the standard strategy group, which aimed to lower blood sugar levels to achieve an A1C of 7 to 7.9 percent, or the intensive strategy group, which aimed for an A1C target of less than 6 percent. On average, the intensive strategy led to A1C of 6.4%. The intensive strategy was halted early due to excess mortality. The current analysis looked specifically at whether the rapid reduction or maintenance of lower A1C levels was responsible for the excess mortality, as many hypothesized it had been.
The increased risk began emerging within 1 to 2 years after the strategy began to aggressively lower the participants’ blood glucose levels. According to the researchers, the higher than expected number of deaths occurred in study participants in the intensive arm who were not able to lower blood glucose levels to achieve an A1C less than 7 percent. Their analysis suggested that failure to reduce moderately elevated or high levels of A1C levels in people with type 2 diabetes after starting an intensive strategy may be a warning sign and could signal the need to discontinue such treatment in those patients.
The American Diabetes Association recommends that most people with type 2 diabetes set a goal of maintaining A1C levels at or below 7 percent. Previous research has firmly established the benefits of good glucose control, which has been shown to prevent or reduce many diabetes-related complications, such as impairment of vision, kidney failure, and nerve damage. However, the ADA’s guidelines recommend that people with type 2 diabetes discuss blood glucose goals with their physicians, as tight control may not be warranted in all patients.
While the most recent analysis of ACCORD data appears to answer the question of whether rapidly reducing A1C levels, or achieving low A1C levels, can be seriously harmful, it does not provide answers as to what did cause the excess mortality, Dr. Riddle said.
‘We still don’t know why more patients in the intensive group died,’ he said. ‘We wish we knew what it was about this group that caused the additional risk, but we don’t.’
Dr. Riddle said his team is continuing to investigate potential causes of that mortality, including the role of weight gain during the study.
The glycemic control trial was one of three clinical trials that comprised the ACCORD study. The ACCORD study was designed to determine if a strategy of intensive lowering of blood glucose levels, intensive lowering of blood pressure, or treatment of blood lipids with a fibrate drug plus a statin drug, can reduce the risk of major cardiovascular events – heart attack, stroke or death from cardiovascular disease – compared to standard control of glucose, lipids, and blood pressure in patients with type 2 diabetes who are at especially high risk of CVD. ACCORD is sponsored by the National Institutes of Health, primarily the National Heart, Lung, and Blood Institute, with additional funding and scientific expertise contributed by the National Institute of Diabetes and Digestive and Kidney Diseases.
To reach Dr. Matthew Riddle, phone: 503-494-8488 or email: firstname.lastname@example.org.
Diabetes Care, published by the American Diabetes Association, is the leading peer-reviewed journal of clinical research into one of the nation’s leading causes of death by disease. Diabetes also is a leading cause of heart disease and stroke, as well as the leading cause of adult blindness, kidney failure, and non-traumatic amputations.
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