Tight not always right for controlling diabetes
■ Studies suggest that the strategy of more blood glucose control could harm patients and that greater attention is needed on overall health.
By Victoria Stagg Elliott — Posted May 4, 2009
Tight control of blood glucose levels, the bedrock of diabetes care for some time, may not be the best option for all patients with the type 2 form of the disease. The burden of complex treatment regimens, risk of low blood glucose, possible weight gain and expense of reaching these goals may not always be worth it. In addition, hemoglobin A1c targets should be individualized, according to a review of recent studies in the June 2 Annals of Internal Medicine.
"It's time to look at the patient with diabetes as an individual who has more issues than just blood sugar," said Victor Montori, MD, lead author and professor of medicine at the Mayo Clinic in Rochester, Minn. "It's key that we change the emphasis from blood sugar to well-being, adequate preventive care and adequate cardiovascular risk reduction."
Researchers pooled several large randomized trials comparing effects of working toward various glycemic targets. Tight control made no impact on all-cause mortality, cardiovascular death, stroke, amputations or microvascular complications. This diabetes care strategy also increased the risk of hypoglycemia and weight gain.
Aiming for ever-lower blood glucose levels has been the emphasis of diabetes care from several organizations because of evidence indicating the approach reduces the risk of long-term complications. Most urge that the majority of patients achieve hemoglobin A1c numbers around 7% or lower.
This paper is the latest to suggest this strategy may not always be proper. Results of projects released in the past year, such as the Action to Control Cardiovascular Risk in Diabetes, the Veterans Affairs Diabetes Trial, and Action in Diabetes and Vascular Disease -- Preterax and Diamicron Modified Release Controlled Evaluation, noted that efforts to tightly control blood glucose levels may not mean lower risk of cardiovascular disease. They may even increase the risk of death for some.
"Hypoglycemia can be very dangerous in the older population, particularly for older patients who have co-existing illness and are on numerous medications," said William Duckworth, MD, director of diabetes research at the Phoenix Veterans Affairs Health Care Center and VADT's principal investigator.
In response, the American College of Cardiology, the American Diabetes Assn. and the American Heart Assn. published a statement in their respective journals last year saying most patients should still aim for an A1c of 7%. Those with a history of severe hypoglycemia, short life expectancy and advanced complications may not need such intense glycemic control. A commentary in the April 15 Journal of the American Medical Association also suggested that younger patients who have not had the disease long and do not have many cardiovascular risk factors are most likely to benefit from tight control. "The goal for the majority of people is a hemoglobin A1c as close to normal as possible," said Bruce Bode, MD, a spokesman for the Endocrine Society and associate professor at Emory University School of Medicine in Atlanta.
Response to this more recent paper varied. Some praised it for bringing attention to the fact that tight control may not be best for everyone.
"We are treating people, not numbers," said Rodney Hayward, MD, co-director of the VA Health Services Research and Development Center of Excellence in Ann Arbor, Mich. "People have different goals in their life. For them to check their blood sugar multiple times a day may come at a huge cost and may not really be valuable. It may even be dangerous."
But the findings also drew criticism. Some experts questioned the conclusions because researchers lumped together several trials focusing on very different populations. Many also expressed concern that worries about the patient burden of getting to low numbers may have been overblown.
"I agree that glucose targets need to be individualized. I don't necessarily think it's appropriate to combine all of these studies together," said Irl B. Hirsch, MD, professor of metabolism, endocrinology and nutrition at the University of Washington School of Medicine in Seattle. "I disagree with some of the conclusions about the burden of care on the patient."
The authors say tight blood glucose control is a good option for some patients but, because it is not for all, advocate that A1c numbers not be used for pay-for-performance and other quality measures.