Peter J. Dyck, M.D., is director of the Peripheral Neuropathy Research Laboratory at the Mayo Clinic and professor of neuroscience at the Mayo Clinic College of Medicine.
Q What are the newest treatments for diabetic neuropathy?
DR. PETER J. DYCK ADVISES:
A Diabetic neuropathy is a type of nerve damage that occurs in people with diabetes which may cause a loss of sensation, numbness or pain, especially in the feet. The best way to prevent or improve diabetic neuropathy is to control the blood sugar level, and your doctor can help you develop a plan to do that.
In some cases, it's enough just to lose weight, increase the amount of exercise and improve diet. In others, an oral medication might be needed. Still others may need intensive insulin therapy.
Experts don't completely understand the mechanics of how high blood sugar leads to nerve damage. Sugar is itself not thought to be toxic. Instead, scientists think that damage to blood vessels and nerve fibers is caused by substances formed when sugar is metabolized.
While the fasting plasma glucose (FPG) test is important for diagnosing diabetes, the best test for monitoring your blood sugar on a continual basis is Hemoglobin A1c, which measures the amount of sugar bound to hemoglobin (the protein in red blood cells that carries oxygen from the lungs to the rest of the body). The Hemoglobin A1c gives your doctor an idea of what your blood sugar has been doing for the past six to eight weeks, rather than the snapshot in time that the FPG test gives us. For some diabetic patients, the Hemoglobin A1c will need to be taken every six to 12 weeks to keep blood sugar under control.
Several drugs are approved to treat the pain that comes with diabetic neuropathy. The major ones are gabapentin (Neurontin) and duloxetine (Cymbalta). Over-the-counter drugs such as aspirin and ibuprofen can also help.
So far, there aren't any new drugs approved to treat the neuropathy itself.
Alpha lipoic acid, an antioxidant, has been used with some success in Germany. There, doctors give it intravenously. The drug is not approved in the United States, but is available in an oral form as a dietary supplement. Studies in Europe have shown that it not only is effective in treating pain but also appears to improve muscle strength.