New treatments put diabetes patients in the driver's seat

Although achieving control of blood glucose levels is crucial for the 20.8 million Americans-7% of the population-who have diabetes, the heralding of the new drugs is a bit muted by critics who argue that the new crop is not as efficacious as the older drugs. For example, a Tufts-New England Medical Center analysis of 29 studies found that the new incretin drugs reduce average blood sugar levels (hemoglobin A_1c) by 1% or less, while older medications such as metformin reduce glucose levels by up to 2%.

Although the new incretins have been shown in animal models to produce new islets in the pancreas and to increase the capacity of the pancreas to produce insulin, there are no data at this point to support such results in human studies. "Now it could well be that as we study these drugs longer term, we will see longer term benefits," Ehlers said. He went on to explain why both old and new diabetes drugs appear to lose efficacy slowly over time, and thus need to be supplemented with additional drugs. "The underlying disease appears to progress and people generally believe that the level of insulin resistance may not change, but the ability of the pancreas, or the beta cells, to produce insulin slowly declines. And no matter what drug you start with, you can't seem to be able to slow down the decline in the beta cells. So over time patients just become less and less able to produce enough insulin to meet the demands in the face of ongoing resistance to the action of insulin."

Gaining ground