April 29 (HealthDay News) -- Gene therapy shows promise in treating diabetic polyneuropathy, a disorder that commonly affects diabetics who've had the disease for many years, a new study finds.

Researchers in Boston found that intramuscular injections of vascular endothelial growth factor (VEGF) gene may help patients with diabetic polyneuropathy. The study included 39 patients who received three sets of injections of VEGF gene in one leg and 11 patients who received a placebo.

Six months after treatment, the patients who received the VEGF gene injections showed greater improvements in sensory symptoms and pain than those who received the placebo.

Loss of sensation and pain in the legs and feet, weakness, and balance problems are among the symptoms associated with diabetic neuropathy. The loss of sensation means that ulcerations on the feet may go undetected, which can lead to amputation.

"Most patients had fairly severe neuropathy, and the expectation for improvement was therefore not high," Dr. Allan Ropper, executive vice chair of the neurology department at Brigham and Women's Hospital in Boston, said in a hospital news release.

The VEGF gene used in the study is active without packaging it in a virus, which is a major safety advantage, according to the researchers.

"The study shows that this form of gene transfer therapy can be performed relatively safely, but further investigation using a larger study group is needed before it can be introduced as a mainstream therapy," Ropper said.

The study was presented in Seattle at the annual meeting of the American Academy of Neurology.

SOURCE: Brigham and Women's Hospital, news release, April 28, 2009