Preventing Type 2 Diabetes
Can drugs prevent the onset of type 2 diabetes? One class of drugs shows promise, but it has its drawbacks.
Unrelated to its effects on beta cells, TZDs may lower the cardiovascular risks of diabetes. Given that heart problems and strokes are among the most deadly complications of diabetes, this may prove an important effect of the drugs.
While TZDs also have the ability to lower glucose, their abilities to do so are modest compared with other medications.
"TZDs are not very potent when used as monotherapy," says David Nathan, director of the diabetes center at Massachusetts General Hospital and a professor of medicine at Harvard Medical School. "In fact, they are considerably less potent than the sulfonylureas or metformin [standard diabetes drugs]." Nathan tells WebMD the greatest benefit may come by combining TZDs with other drugs, although he cautions that the results of doing so are not yet fully understood.
Another potentially significant benefit of TZDs is that they appear to lower the levels of free fatty acids in the bloodstream, a new focus of attention for diabetes experts because of their connection to diabetic complications. "I think that's an important aspect of TZDs," says Paul Jellinger, MD, past president of the American Association of Clinical Endocrinologists. "It's one of the apparent benefits of TZDs that hasn't been widely appreciated yet."
A New Direction?
Based in part on the results of the TRIPOD study, Buchanan believes the emphasis of diabetes treatment needs to be shifted.
"Basically, right now, we treat people whose glucose levels are already high enough to cause long-term complications and we try to get their levels lowered," he says. "But by the time someone has gotten to the point of diabetes, they've probably lost about 80% of their beta-cell function. Someone with just Impaired glucose tolerance [an aspect of pre-diabetes] has already lost about 50% of their beta-cell function."
Buchanan wants diabetics and doctors to understand better the difference between the manifestations of disease -- heightened glucose levels -- and the loss of beta-cell function that may be causing them.
"The current paradigm of diabetes treatment is focused on the sprint -- what your glucose levels are -- instead of the marathon, which is how the disease is progressing," he says.