Besides chemistry, psychology, and other prerequisite courses for her major, Mary Beth Goeser ('90 BSN) enrolled in a clinical study, the Diabetes Control and Complications Trial (DCCT), during her first year at The University of Iowa. Participation reassured her mother, a nurse in their western Iowa hometown of Harlan, that her daughter's diabetes would be carefully monitored.
As required by the study, which followed 1,441 people with type 1 diabetes at 29 centers in the United States and Canada, Goeser measured her blood sugar level four to six times daily and called the clinic weekly with a report. She self-injected with insulin three or four times each day. Every month she visited the UI clinic for a hemoglobin A1C test and guidance from study dieticians, physicians, and nurses.
Three years after she graduated, DCCT findings were reported and diabetes care was transformed. Results showed that intensive insulin therapy—more than two injections a day or the use of an insulin pump to deliver a continuous infusion of insulin—kept patients' blood sugar levels under good control and as close to normal as safely possible, and improved their chances of avoiding long-term complications such as eye, kidney, or nerve damage.
"Prior to the DCCT findings, it was never clear that lowering blood sugar really prevented long-term complications," said William Sivitz, MD, professor and director of endocrinology and metabolism.
"The findings stimulated worldwide efforts to develop new drugs, improved insulins, and devices that monitor blood sugar continuously."
Today Goeser travels western and southern Iowa as a diabetes clinical manager for Medtronic Diabetes. She teaches providers and patients how to use continuous glucose monitors or the
insulin pump, which is the device that supplies the insulin her own body can't produce to maintain a healthy blood sugar level. And she continues her involvement in a clinical trial, the Epidemiology of Diabetes Interventions and Complications (EDIC), a follow-up study of the DCCT patients, including 58 at the UI.
"The research staff is like family to me," Goeser said of her 23-year connection with diabetes studies at the University. "I've benefited greatly from the unparalleled diabetes care provided over the years at UI Hospitals and Clinics."
Researchers hope the EDIC study, which has funding from the National Institutes of Health (NIH) until 2016, will help determine the impact of intense glucose control on patients' cardiovascular and nervous systems, eyes, and kidneys, as well as help reveal the natural progression of diabetes, Sivitz said.
"When the DCCT ended, we didn't know the effect of intense glucose control in terms of large-vessel events—heart attacks and strokes— because the study population was relatively young.
By continuing to follow them, we found that the initial randomization to intensive therapy actually reduced the ultimate number of cardiac events by about 50 percent. It just took another 10 years to see that," Sivitz said. Those findings were published in the New
England Journal of Medicine in 2005.
"This is the most well-characterized group of people with type 1 diabetes ever studied," said Meg Bayless, RN, coordinator of the Diabetes Clinical Research Programs directed by Sivitz, the principal investigator for the UI's portion of the EDIC study.
Similar studies involving people with type 2 diabetes have reinforced the value of rigorous control of blood sugar.
A current NIH-funded trial known as the Action to Control Cardiovascular Risk in Diabetes (ACCORD) includes the UI among approximately 60 study sites testing ways to lower the risk of heart disease and stroke in adults with type 2 diabetes. Findings from the study are forthcoming.
Sivitz said the NIH and study investigators expect results of ACCORD to have major implications toward the management of type 2 diabetes.
The UI's role in these multi-center studies, as well as numerous investigator-initiated studies, has a direct impact on diabetes care.
"Research and clinical trials have taken us from the belief that it's very hard to prevent complications to the idea that we can prevent complications with control," Sivitz said. "Now we want to develop better ways to control diabetes that are easier for patients to use and less invasive."
For example, Mark Arnold, PhD, professor of chemistry in the College of Liberal Arts and Sciences and director of the UI Optical Science and Technology Center, has been working on a way to measure blood glucose that would be more convenient and less painful. Rather than the conventional method—pricking a finger to produce a drop of blood placed on a test strip that inserts into a glucose meter—Arnold's technique passes a beam of near infrared light of glucose from the information that appears in the resulting spectrum.
"To be able to measure glucose non-invasively is what some people call the Holy Grail of diabetes monitoring," said Arnold, who holds the Edwin B. Green Chair in Laser Chemistry. A noninvasive method would encourage more frequent testing and show the rate and direction of glucose change, alerting patients to potentially dangerous low blood sugar.
Because glucose is such a minor component in human tissue—compared to water, proteins, fat, and other more prominent compounds—and has spectral characteristics similar to other compounds in skin, the challenge for Arnold's team is to develop technology that can measure glucose accurately from a noninvasive measurement. His research group has successfully measured glucose non-invasively in animal models and now is assessing the feasibility in human subjects. He stressed, however, that a practical device for noninvasive glucose testing is many years away. |
