The American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) published an updated consensus statement in the December 2008 issue of Diabetes Care concerning the management of high blood glucose in people with type 2 diabetes.
These guidelines are timely because they appear at a time when a dizzying number of therapeutic options have become available. I can only mention some of the highlights.
The ADA and EASD guidelines included several generalizations:
- Early diagnosis is important so that treatment can be started quickly.
- The target for HbA1c is less than 7 percent.
- Patients should try to reach that target with as little delay as possible.
Most often, the first step in the management of type 2 diabetes is lifestyle measures to decrease weight and increase activity. Even modest weight loss is likely to improve glucose control, but most people with type 2 diabetes will require medications within 1 year.
In my experience, patients are all too often allowed to continue too long with only lifestyle measures, even when no obvious progress is being made in weight loss or glucose control. In addition, when initial HbA1c levels are quite high, lifestyle measures alone will not lower glucose levels adequately, and so medications need to be started along with the lifestyle measures.
Metformin is recommended as the initial medication because it does not cause weight gain or hypoglycemia (low blood glucose) when taken alone, and it is relatively inexpensive. Metformin, however, can produce gastrointestinal side effects and is contraindicated in people with reduced kidney function.
When additional medications are needed, the next recommended step is to add a sulfonylurea or to start insulin therapy (i.e., injecting insulin). Both can lower blood glucose rapidly; however, insulin remains the most effective treatment for type 2 diabetes. It always works and continues to work even though the dose often has to be raised over time. Insulin also improves the lipid profile. Both insulin and sulfonylureas can be associated with weight gain and hypoglycemia.
Again, it's been my experience that doctors frequently wait too long before prescribing insulin, no doubt because of the reluctance many patients express about beginning regular injections. Once insulin therapy is started, however, most patients quickly learn to live with it.
If glucose levels are not adequately controlled with metformin and sulfonylurea and the decision is made to hold off on insulin injections and continue with oral medications, then the recommendation is to choose either a thiazolidinedione (rosiglitazone [Avandia®] or pioglitazone [Actos®]), a glucagon-like peptide 1 [GLP-1] agonist such as Byetta), or Januvia® (sitagliptin), an oral medication that blocks the breakdown of GLP-1. Actos is associated with an improved lipid profile and a probable decrease in heart attacks; some studies found that Avandia increased the likelihood of heart attacks.
Avandia and Actos are expensive and both can cause fluid retention, heart failure, weight gain, and bone fractures. Byetta produces weight loss but requires two injections daily, is expensive, and frequently causes gastrointestinal side effects. The long-term safety of Byetta and Januvia is not established.
When they discuss treatment choices with their physician, people with type 2 diabetes should be aware of these recommended priorities for treatment, as well as of the positive and negative features of each therapeutic option. It is an unfortunate fact that type 2 diabetes worsens over time, so that insulin or multiple oral medications are needed to control blood glucose well enough to diminish the chances of long-term complications.
