MONDAY, Feb. 17, 2003 (HealthDayNews) -- People with diabetes often suffer circulatory problems, vision loss and heart attacks, to name just a few of the untoward effects that can come from a buildup of sugar in their tissues.
Now researchers report that a derivative of vitamin B1 halts much of that sugar buildup, which may lead to a vastly improved quality of life for many with the disease.
"It's a huge breakthrough," says Dr. Michael Brownlee, an endocrinologist at the Albert Einstein College of Medicine in New York City and one of the authors of the new report, which appears in the current issue of Nature Medicine.
Since 1968, four major pathways have been pinpointed for causing much of the damage of diabetes by helping glucose-derived compounds, known as triosephosphates, to accumulate in vascular and nerve cells, he explains.
Through his research, Brownlee realized that by activating the enzyme transketolase, triosephosphates could be turned into harmless chemicals.
Transketolase is a thiamine-dependent enzyme. "Thiamine [also known as vitamin B1] itself activates it about 20 percent," Brownlee says, but this isn't enough to stop the glucose-derived compounds from building up in healthy cells. "Serendipitously, I decided to give a lipid-soluble derivative so it would be better absorbed."
In research in the laboratory on cultured cells, the researchers found that benfotiamine increased levels of transketolase by 300 percent. "So that was kind of lucky," Brownlee notes.
Benfotiamine blocked three pathways completely. While its action has not been tested on a fourth pathway that controls nerve cells, it may work similarly there, he adds. At any rate, blocking three pathways is enough to prevent many diabetes-related complications.
When 20 rats that had suffered diabetes for nine months were given benfotiamine, diabetic retinopathy was averted, Brownlee adds. Not a single rat developed the retinopathy, which is a condition that occurs in many diabetics when high blood sugar damages the retina of the eye, leading to visual problems and often blindness.
While several pharmaceutical companies are working on releasing drugs that will halt one of the pathways, "this is one compound that prevents all three of the pathways," Brownlee says.
There is every reason to think benfotiamine will work equally well in humans, he notes, since the mechanism in humans is the same as that of rats.
Brownlee plans to study the effect of this compound in surrogate human cells.
Those with diabetes should not run out to buy thiamine-rich foods or vitamins, he stresses. "Thiamine doesn't do the same thing" as benfotiamine, and the derivative is not sold in North America, he says.
However, there is good news, Brownlee adds. A small company in Germany called WorWag Pharma has been producing and selling benfotiamine for some time, to treat various neuropathies. Therefore, the medication is already used in humans and is deemed safe, he notes.
How much benfotiamine would be the right amount to halt the harmful pathways in humans with diabetes is not known, Brownlee adds: "I know it's not harmful, but I don't know what the right dose is."
Dr. Richard Hellman, an endocrinologist at the University of Missouri-Kansas City School of Medicine says he thinks this finding is "very promising." The researchers have shown a very particular effect on an enzyme that can possibly halt complications of diabetes, he notes. "I think it's a very good study."
However, "the question, when looking at a particular agent, always is: What else does it do? We need to know what it [benfotiamine] does over time" and ascertain that it doesn't cause damage in other areas of the body, he says.
"This is an important first step," Hellman says, but "there is so much more we need to know about this substance. I would strongly recommend that people not try to procure it" before more extensive tests have been done to ensure it isn't harmful.
Brownlee agrees that double-blind, placebo-controlled trials are needed. Still, "it has the potential of being something that in quite the near future could be taken."
More information
For those interested in more about complications of diabetes, try the National Institute of Diabetes and Digestive and Kidney Diseases or the Joslin Diabetes Center.
