Neuropathy is common for people with diabetes, ranging from numbness to shooting pains as the peripheral nerves are damaged by the disease's progression.
More than half of the people with diabetes -- literally millions -- experience some form of neuropathy, which in severe cases can lead to severe infections and amputation. But there's no effective treatment.Researchers hope a clinical trial being conducted at 41 hospitals around the country will change all that. The centers, including University of Utah Hospital, are recruiting diabetic patients with moderate neuropathy for the two-year, double-blind study of a medication, Zenarestat, produced by Parke-Davis. Double-blind means neither patient nor doctor knows who is getting the study medication and who is getting the "look-alike" placebo.
What form diabetic neuropathy takes can vary widely, said Dr. Mark Bromberg, a neurologist who is the principal investigator for the study at the U. Some people complain of a shooting pain, burning pain or a bandlike constriction, usually in the foot or ankle. Others lose sensation in their feet and complain it seems like they are walking on stumps. Another manifestation, called autonomic neuropathy, affects blood pressure and blood flow. The different versions of neuropathy can also combine.
It's possible for someone to cut a foot and because wounds heal poorly, get an infection that can be life-threatening. Often people with neuropathy don't know they've hurt themselves at all.
The study is based on expanded knowledge about neuropathy, Bromberg said. For instance, while no one knows why high blood sugar causes damage to the nerves, studies have shown that people who have a pancreatic transplant and begin producing their own insulin can see a reversal of at least some of the peripheral nerve damage. And people who can get strict control of their diabetes experience some stabilizing of the neuropathy.
Researchers do not know how neuropathy works. They theorize that high glucose in the nerve cell changes to sorbitol, which ultimately leads to decreased levels of myo-inositol in the cell. The enzyme aldose reductase seems to speed up that process, much as lighter fluid will get the barbecue going faster than a match alone will, Bromberg said. The theory is that if one can block the aldose reductase enzyme, the rate of neuropathy can be slowed or reversed.
This clinical trial, which will be conducted simultaneously at 41 centers across the United States, hopes to enroll 1,130 people with "just so" diabetic neuropathy.
Bromberg calls it "just-so" neuropathy because there must be symptoms like numbness, tingling or discomfort in the feet, but it can't be too advanced.
Participants must be between the ages of 18 and 70. People who have had gout shouldn't participate. Neither should those with certain cancers, heart disease or other conditions that could preclude completing the two years of the study.
Parke-Davis will bear the cost of all study-related items, except transportation. Participants will be required to have three closely scheduled appointments each at the beginning, one-year and two-year marks to have a battery of tests, including chest X-rays, EKGs, nerve conduction studies and more. There will also be periodic checks in between. But the study is not intended to replace regular care by a family physician or specialist, Bromberg said.
Those who stay with the study for the full two years will qualify for free medication for a year when the study is completed.
To see if you qualify for the study or for more information, call Donna at 581-4944.