UW Researcher Shares the Latest on CGM
As a University of Washington (UW) professor, medical director of the UW Diabetes Care Center, practicing endocrinologist, and researcher, Dr. Irl Hirsch spends a great deal of time trying to improve the lives of people with diabetes, including his own. He has type 1 diabetes. His latest work involves new technology designed to give people more frequent and accurate information about their disease.
High-Tech Device Gives Details & Trends
Last year, Hirsch and his UW team wrapped up one of the JDRF-funded continuous glucose monitor (CGM) human trials, which showed that CGM systems do provide significant improvement to blood sugar control in adults. And better long-term glucose control should result in fewer complications down the road.
The CGM gives a real-time snapshot of glucose levels using a small sensor inserted under the skin that transmits the user’s information to a hand-held device. The system provides readings, stores data on the effects of food and exercise, and shows whether levels are trending up or down, and how fast. It also sounds a warning when the glucose is too high or too low.
Optimism Tempered with Reality
“This is a new tool in the toolbox, and it can make your life a little better—if you have realistic expectations” cautions Dr. Hirsch. “Everyone thinks it will be a panacea, but it’s fundamentally related to patient behavior. When you use this technology appropriately, you are actually spending more time thinking about and adjusting your diabetes, not less time.”
“You need to be willing to change your behavior. The patients that did the best in the JDRF study did what we’ve been saying for years--give your insulin about 10 or 20 minutes before you eat. They figured this out because they were watching their blood sugar the whole time.”
Is CGM Suited for Kids?
“This technology is absolutely appropriate for kids and teens,” says Hirsch. “In the study, the kids, teens, and adults who wore it six or seven days a week did very well. In the right people, it works great.” Hirsch predicts that the children—and their families—who will be most successful should be diligent about their diabetes management, interested enough in this new technology to use it well, and have the support and follow-up of a good health care team.
Hirsch says the system works well with pumps or shots, and the CGM sensor site usually stays very healthy because there’s no infusion from insulin, which is a foreign protein. Pump sites often get inflamed because of the infusion of insulin.
For him, it’s a vital new tool for diabetes management. “If I had to choose between a CGM device and a pump, the CGM is much more important technology to me. I can watch my blood sugar and see the trends. If you’re paying attention to it, you’ll never hit bottom.”
Success Affected by Frequency
Consistency with this technology is key. Results of the JDRF study suggest that patients who used the device at least six days a week had substantially lower A1c levels after six months than those who used it less than six days a week.
“One of the things we learned from the study is that there’s no real benefit if it’s not used six or seven days a week,” says Hirsch. When you wear it all the time, you do great. If you only wear it one or two weeks out of the month for affordability, you’re not going to get any benefit out of it.” Ultimately, he says it’s patient behavior—consistent and conscientious diabetes management—that determines success with CGM.
Barriers: Cost, Physician Adoption
Insurance reimbursement, along with some doctors’ resistance to invest a great deal of time and energy to work with the new CGM technology, remain hurdles to access. Without insurance, the first-year cost can be up to $4,000 ($650–1,000 to start, plus $250 per month for disposable sensors). Costs should decrease in subsequent years.
One of the goals of the JDRF study was to accelerate insurance coverage of the CGM system. More national companies have expanded coverage, especially for people 25 years or older. In our region, Regence, Premera, and Uniform Medical now have limited coverage. Hirsch thinks that insurance will increase with more CGM follow-up research studies and a strong grassroots effort among patients.
Looking Back, Looking Ahead
Hirsch notes the tools of the future will include smaller, thinner pumps, sensors, and other equipment. Faster insulin, smart insulin—injectable daily insulin that goes up as blood sugar goes up—and closed-loop systems are also promising developments on the horizon. Combined with an insulin pump, CGM is a key component of the artificial pancreas model.
He’s excited about the scientific potential to identify and treat complications earlier, new drugs for complications, and methods—possibly a vaccine—to slow or prevent the onset of type 1 diabetes, as well as predicting who may get the disease.
Although it’s difficult to wait for the new treatments and technologies if you have type 1 diabetes, Hirsch advises that perspective is key. “I think the most exciting thing that’s happened is watching where we’ve gone with the sensors in such a short period of time,” says Hirsch.
“It wasn’t that long ago that we used urine tests. We didn’t have glucose meters or A1c,” he says. “If you’re the parent of a small child, it’s hard to fathom how far we’ve come in such a short time. If we have the advances in the next 20 years that we’ve had in the last 20, it’s going to be remarkable. I can’t even predict what it will be like.”