Surprising New Diabetes Data

(page 2 of 2)

They were wrong. The most important finding is not necessarily that more patients in the aggressive treatment group died than in the standard treatment group. The difference was relatively small. Among the 10,251 patients, 257 people given intensive treatment died over four years, compared to 203 in the control group. That's just more than one additional death per 100 people over the four-year period.

Instead, the real significance is that the expected benefits were not found. When the trial was started, researchers hypothesized that keeping one measure of blood sugar (called HbA1c) below 6 instead of the standard 7.5 would reduce heart attacks and other cardiovascular events by at least 15%. The lack of such a benefit casts serious doubt on the more intensive use of the drugs, especially because they come with a long list of side effects, such as fluid retention (which can be life-threatening) and weight gain (which makes diabetes worse).

Focus on Clinical Outcomes

And the new finding raises red flags about using surrogate markers in general—and about whether the FDA should approve drugs just because they lower blood sugar or cholesterol. "The use of surrogate end points in the drug approval process has been problematic," wrote Dr. Bruce Psaty of the University of Washington and Dr. Curt Furberg of Wake Forest University in a recent New England Journal of Medicine editorial on the subject of diabetes treatment. They and many others argue that drugs should be tested to see if the medicines actually reduce disease before they are allowed on the market, instead of being approved just because they make the numbers "better." That would increase the costs of drug development. But it would also limit the chances of people being harmed, with no hope of benefit.

Concludes Rosen: "We urgently need to change the regulatory pathway for drugs for the treatment of type 2 diabetes to make clinical outcomes, not surrogates, the primary end points."

What does all this mean for diabetes patients? They may not have to use so much medication in an effort to keep blood sugar levels down, thus reducing the side effects. But meanwhile, they should strive to reduce other risk factors for cardiovascular disease, such as by losing weight and keeping blood pressure in check.

Carey is a senior correspondent for BusinessWeek in Washington .