It's still extremely important for people in the earlier stages of diabetes to do as much as they can to keep their blood sugar as close as possible to normal levels. There's little doubt that this cuts the risk of the microvascular (kidney, eye, and nerve) and macrovascular (heart attack and stroke) complications that plague people with diabetes.
But three recent studies -- including one by William Duckworth, MD, and colleagues in the current issue of the New England Journal of Medicine -- suggest that people with advanced diabetes have more important things to worry about than making heroic efforts to get their blood sugar down to near-normal levels.
"Blood pressure and blood lipid control are more important than very intensive glucose control," Duckworth, director of diabetes research for Phoenix Veterans Affairs, tells WebMD. "That is not to say glucose control is not important: I said very intensive glucose control."
Not long ago, nobody would have agreed. Tight glucose control -- the tighter the better -- was the mantra for all diabetes patients. In fact, it took some time (and the invention of new blood sugar-lowering drugs) for researchers to put this mantra to the test.
Now, Duckworth's study is the third major study to find that although patients with advanced diabetes must keep their blood sugar from going wild, intensive blood sugar control offers little extra benefit.
How Low Should Blood Sugar Go?
What does intensive blood sugar control mean? Diabetes doctors and patients usually focus on A1c (glycated hemoglobin level or HbA1c), a measure of blood sugar control over time. The ADA says people with diabetes should try to get their A1c levels below 7%. Those who can't do this with one oral diabetes medication should make more "intensive" efforts by using multiple medications and/or insulin.
There are risks. More drugs mean more side effects -- and with some diabetes drugs, a very unwanted side effect is weight gain. Much more important is the risk of a sudden crash in blood sugar: hypoglycemia. A severe hypoglycemic event means an altered mental state, unconsciousness, or even death. And there's evidence that a severe hypoglycemic event increases a person's risk of heart attack or stroke.
In a new guideline issued this month, The American Diabetes Association, the American College of Cardiology, and the American Heart Association still recommend intensive glucose control for most adults with diabetes.
But the guideline also notes that in advanced diabetes, where heart disease may already be well developed, blood sugar control has "minimal or no role." Jay S. Skyler, MD, associate director for academic programs at the University of Miami's Diabetes Research Institute, is lead author of the guideline.
"We are going to leave the A1c target at 7% for these people. But we give their doctors the opportunity to make adjustments either up or down depending on the circumstances," Skyler tells WebMD. "We want better glucose control in those younger patients with earlier diabetes ... and we relax the standard if the risk of hypoglycemia becomes such that to reach 7% you have to do it with some struggle."
Skyler says that most diabetes experts can get most patients -- even those with longstanding diabetes -- pretty close to an A1c of 7%.
"If they are under 9% but not close to 8%, I would like them to work harder," he says. "You can get people under 8% without working too hard."
Duckworth, who has treated diabetes patients for 40 years, says that's an unrealistic goal for many patients.
"To my older patients with longstanding diabetes, I say, "We will get your glucose down to reasonable levels, to an A1c of 9%, and try to get it lower if we can do it without risking severe hypoglycemia, and without decreasing your quality of life, and without causing financial or other burdens," Duckworth says. "We simply don't have evidence that a lower A1c is worth it for these people with advanced diabetes who are in their 60s and older."
Skyler says much of the problem with glucose control is the reluctance of patients -- and doctors -- to take or to offer insulin. And this reluctance, he's found, is largely based on two misconceptions about insulin.
The first misconception is that it's painful to take insulin injections. Diabetes patients must frequently test their blood sugar, and that means pricking their finger to get a drop of blood. Many patients (and, Skyler says, many doctors) think that an insulin injection will be even more painful -- but it's actually far less of a bother.
And because many patients put off taking insulin until late in the disease, people have come to associate insulin with the bad outcomes seen in very advanced diabetes. Taken earlier in the course of disease, insulin actually prevents these bad outcomes.
The Duckworth study appears in the Jan. 8 issue of the New England Journal of Medicine. The Skyler article appears in the January issue of Diabetes Care.
Duckworth reports receiving consulting fees from Novo Nordisk, GlaxoSmithKline, and Caremark and lecture fees from Sanofi-Aventis. Skyler receives support from, holds stock in, and serves as a board member and/or advisor to a number of pharmaceutical and medical device companies.