better, longer lives
What's a little blood sugar problem? Diabetics can watch their diets and take insulin if they need to, right?
Sounds simple enough, but the problem is that diabetes is still the leading cause of blindness, heart disease, stroke, kidney failure, nerve damage and amputations in this country. It's also number seven among the top ten leading causes of death. The Health Science Center is helping patients and caregivers worldwide with diabetes-related problems.
For example, health care providers now can prevent the majority of leg amputations in their diabetic patients. They can also alert parents early to their child's vulnerability to diabetes and ways to help prevent its development. They can help patients avoid kidney failure and offer type II diabetic patients a more effective oral medication.
Ralph A. DeFronzo, MD, professor of medicine and chief of the division of diabetes, is helping to define why tissues of diabetic patients respond poorly to their own insulin. He is leading the search for genes that cause diabetes, focusing on the genetic basis of diabetes in Hispanics, who are three times more likely to develop the disease than Anglos. The Health Science Centerís multiyear San Antonio Heart Study led by Michael P. Stern, MD, professor of medicine and chief of clinical epidemiology, originally helped reveal the high rate of diabetes among Hispanics in Texas and Mexico. Dr. Stern also is actively pursuing the genes for diabetes.
Researchers including Stephen M. Haffner, MD, professor of medicine, are building on epidemiological findings with projects including the Diabetes Prevention Program, funded by the National Institute of Diabetes and Digestive and Kidney Diseases and designed to locate and educate individuals with impaired glucose tolerance or other signs of potential diabetes.
Dr. DeFronzo's group also has conducted clinical trials of the drug metformin for treatment of type II, or non-insulin dependent, diabetes. "Prior to metformin, only 15 to 20 percent of patients taking sulfonyureas (the only class of drugs available for the problem) had well-controlled blood sugar levels," said Dr. DeFronzo. "Now, with metformin, we anticipate that 50 to 60 percent of patients will be well controlled and many will be able to avoid insulin."
Dr. DeFronzo and George B. Kudolo, PhD, assistant professor of clinical laboratory sciences, have shed more light on why diabetics and obese people are more prone to high blood pressure than others. Published recently in the Journal of Lipid Mediators and Cell Signaling, a paper by the pair found that a certain enzyme is elevated in people with obesity and adult-onset diabetes. "This enzyme breaks down another blood-borne substance, called platelet activating factor (PAF), that we think lowers blood pressure," Dr. Kudolo said. "We learned that if PAF is destroyed too rapidly as it circulates in the bloodstream, the blood pressure is more likely to be elevated." Health Science Center faculty Donald J. Hanahan, PhD, professor emeritus of biochemistry, and R. Neal Pinckard, PhD, professor of pathology, were the first to characterize PAF in the 1970s and Ď80s.
In another Health Science Center study, podiatrist David G. Armstrong, assistant professor in the department of orthopaedics, and colleagues are testing new, low-cost evaluation methods to recognize loss of feeling in the feet of diabetic patients. Armed with this knowledge, podiatrists and others can help patients prevent foot ulcerations that often lead to infection and subsequent amputations. The low-tech tests are expected to save millions of dollars in health care costs and prevent many debilitating lower-limb amputations.
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