Results of the three major clinical trials presented here in recent days have confirmed that in treating diabetes, one size doesn’t fit all.
A panel of diabetes experts Tuesday discussed the studies’ findings and what they mean for doctors and their patients. They agreed that while the studies found no benefit on heart disease risk from drastic efforts to lower blood glucose levels in patients with advanced type 2 diabetes, keeping blood glucose levels at or near the currently recommended ADA target has other benefits, particularly on reducing damage to the small vessels that causes kidney disease and eye damage.
The studies, ADVANCE, ACCORD and the VA Diabetes Trial, were reported during the ADA’s Scientific Sessions, which ended today.
“One of our messages needs to be that treating diabetes is a comprehensive treatment strategy that involves blood pressure and lipid control and aspirin therapy,’’ said Dr. M. Sue Kirkman, ADA’s vice president for clinical affairs. The ABCs of diabetes care – management of A1C, blood pressure and cholesterol – still apply, she said. “We have always talked about the individuality of glucose goals. Some may be candidates for lower goals, and some are candidates for higher.’’
As written now, ADA guidelines recommends lowering A1C to about 7%, a target which “has been shown to reduce microvascular and neuropathic (nerve) complications of diabetes and, possibly, macrovascular disease.’’
But now, the guidance “should be changed to say there is no evidence that reducing glycemic control benefits cardiovascular disease, because that is, in fact, what these data tell us,’’ a revision may be needed, said Dr. Robert Rizza of the Mayo Clinic, a former ADA president.
Panel members cautioned that the studies may not apply to people who don’t fit the profile of those involved in the clinical trials: mainly middle-aged or older people who have had type 2 diabetes for several years, are obese and, in many cases, have a history of heart disease.
“My feeling would be that in patients with advanced disease and age, we should accept somewhat higher (A1C) values,’’ as long as other factors, such as the risk of kidney disease, are taken into account, said Dr. Robert Sherwin of Yale University School of Medicine, also a former ADA president.
Dr. Rury Holman of Oxford University noted that these and other studies suggest that treating diabetes early is more effective and safer than starting treatment after the disease has progressed. “The message the community needs to receive is that the guideline goals are still the same,’’ he said, “but might be flexible in people with advanced disease.’’
Among considerations flagged in the new studies are the danger of hypoglycemia and the effect of weight gain associated with intensive glucose control, said Dr. Eberhard Standl, chair of the International Diabetes Federation. Another factor to consider is the speed at which study participants reduced their glucose levels, he said. “Those with the highest A1C at baseline had higher mortality,’’ so possibly a rapid drop or fluctuations in glucose levels take a toll.
He said long-term studies should be done to find answer to these and other questions. But at present, he sees no need to change the current A1C target for most patients. His advice, “take your time, but reach the (A1C) target and stay on it.’’
The panel, moderated by Dr. Harold Lebovitz, chair of the Scientific Sessions planning committee, agreed that diabetes treatment usually begins later than it should.
“The best way to deal with cardiovascular disease and diabetes is to prevent it,’’ said Dr. Sherwin, because damage begins before glucose levels rise to a point where diabetes is diagnosed. “We’re probably late intervening in the process and we probably need to treat people sooner.’’
One positive note, he said, is that in all three studies, the rate of heart attack, stroke and other cardiovascular problems was about a third less than researchers had predicted. Thanks in part to better control of high glucose levels, “there has been a major fall-off in complications of people with diabetes in the last decade.’’