WEDNESDAY, 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.

More information

The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about diabetes-related nerve damage.

MONDAY, April 20 (HealthDay News) -- Fructose-sweetened soft drinks and other beverages can have a negative effect on the body's sensitivity to insulin and its ability to handle fats, increasing the risk of heart attack and stroke, a new study suggests.

But glucose-sweetened beverages don't have that kind of impact, the study found.

The research included overweight and obese volunteers who for 10 weeks drank either fructose- or glucose-sweetened beverages that supplied 25 percent of their energy needs. During the study period, participants in both groups gained about the same amount of weight, but those who drank fructose-sweetened beverages showed an increase in intra-abdominal fat.

The researchers, from University of California, Davis, also found that those in the fructose group became less sensitive to insulin, which controls glucose levels in the body, and showed signs of dyslipidemia -- elevated blood levels of fat-soluble molecules called lipids.

The study was published in the Journal of Clinical Investigation.

Decreased sensitivity to insulin and dyslipidemia are signs of metabolic syndrome, which increases the risk of heart attack. But whether consuming large amounts of fructose increases heart attack risk over the long-term isn't known, according to the authors of an accompanying commentary.

More information

The American Academy of Family Physicians has more about metabolic syndrome  .

TUESDAY, April 14 (HealthDay News) -- Routine screening for coronary artery disease is of no value for adults with diabetes who have no symptoms of heart problems, a new study finds.

Screening is expensive, at $1,000 per test. But the study of 1,123 people with type 2 diabetes who had no symptoms of heart disease did not identify those at high risk of developing cardiac problems.

The findings were published in the April 15 issue of the Journal of the American Medical Association -- an issue devoted to diabetes.

"It was a surprise," Dr. Lawrence H. Young, professor of medicine at Yale University and a leader of the study, said of the results. "There is no question that coronary artery disease is still a major concern in patients with type 2 diabetes."

While the study did identify a small group of people at increased risk of coronary artery disease, "in the overall population, patients who were screened did not have a better outcome specifically in terms of heart attacks and cardiac death," Young said.

For doctors managing people with type 2 diabetes, "the implication is that a routine patient who is doing well, on state-of-the-art medication such as cholesterol-lowering drugs, aspirin and diabetes therapy, need not be subjected to specialized stress testing," he said. "But patients who have any symptoms of heart disease need to be screened."

The people in the study were randomly assigned to have either a sophisticated screening test -- adenosine-stress radionuclide myocardial perfusion imaging -- or no test. In a follow-up period averaging 4.8 years, 2.7 percent of the people in the screened group had heart attacks or died of cardiac disease, compared to 3.0 percent of those who were not screened.

Many of the people in the study had well-known risk factors for heart disease, Young noted. "In our study, most patients were overweight, and many had other risk factors such as hypertension [high blood pressure] and high cholesterol," he said. "But those were treated well by the primary-care physicians."

Diabetics who should be screened are those with a family history of heart disease or have symptoms of cardiac problems, such as the chest pain called angina, feeling of tightness and heaviness in the chest, and unexplained shortness of breath on exertion, Young said.

One possible reason for the negative finding in the study is that plans for the trial were made eight or nine years ago, and preventive measures have improved since then, said Dr. Steven D. Wittlin, professor of medicine at the University of Rochester in New York, and a member of the study group. The incidence of heart problems found in the study was lower than had been expected, he said.

"During that time, a lot more people have gone on aspirin and ACE inhibitors and other drugs, and that may account for the low rate," Wittlin said.

There are two major findings in the study, he said. "On the one hand, it verifies that people with type 2 diabetes who are middle-aged and have a positive stress test have an increased risk of a cardiac event," Wittlin said. "But the event rate was low enough so that it does not appear to be cost-effective to routinely screen patients with a nuclear stress test."

More information

The American Heart Association   describes the role of diabetes in heart disease.