Clinical Diabetes Technology Meeting 2005
The first annual Clinical Diabetes Technology Meeting was held in San Francisco from April 15-16, 2005. In attendance were over 400 scientists, engineers, and doctors from government, industry, academia, and clinical practice. During the two days of sessions, speakers shared information on a variety of topics, including continuous glucose monitoring, methods of assessing accuracy of continuous sensors, the danger of glycemic variability, new drug therapies, inhaled insulin, and pump therapy, just to name a few. Here is a summary of some of the sessions:
- David Klonoff, MD, the meeting organizer, opened the sessions with a presentation entitled Continuous Glucose Monitoring Technology. He used the analogy of a camera compared to a security camera to examine the difference between today's blood glucose meters and continuous sensors. While meters, like cameras, produce highly accurate snapshots, they provide no information about motion. Today's continuous sensors, like security cameras, are not as accurate as cameras but provide information about motion that is much more useful. Dr. Klonoff then summarized the various technologies and products that are under development.
- William Clarke, MD, spoke about A New Look at Error Grid and Continuous Glucose Error Grid Analysis. Dr. Clarke, whose name is associated with the Clarke Error Grid used to measure accuracy in blood glucose monitors, spoke about the misuse of that technique when applied to continuous sensors because the error grid analysis was not designed to present data in which one point was related to the previous point. Dr. Clarke noted that with trend data from continuous sensors, the absolute point accuracy may not need to be as good as what is available in current home glucose monitors if the rate of change information from the continuous sensor is good. With this in mind, Dr. Clarke presented a new way to look at accuracy in continuous sensors, called the Rate Error Grid, which is comprised of several different charts that include rate-of-change data in addition to the reported glucose reading.
- Irl Hirsch, MD, presented Glycemic Variability - It's Not Just About the A1c Any More, one of the most interesting presentations of the two-day conference. To summarize his presentation, Dr. Hirsch presented interesting data that indicates that glycemic variability -- that is, the excursions from low to high and back again -- needs to be minimized to reduce the risk for developing complications. Dr. Hirsch cited several studies that used umbilical cord cells and showed that wide fluctuations in glucose were more damaging that both normal and high glucose levels. These studies suggest that glucose fluctuations may be involved in the development of vascular damage. Dr. Hirsch suggested that people with diabetes aim to have a standard deviation in their blood sugars of one-third of their mean blood sugar. Thus if your mean blood sugar were 120 mg/dl, you would want your standard deviation to be no more than 40 mg/dl, or one-third of the mean.
- Darrell Wilson, MD, presented a talk entitled Real-Time Continuous Glucose Monitor Use and Patient Selection in Your Practice: What Have We Learned and Where Are We Going? Dr. Wilson, and others in the audience, expressed concern that the large amount of data provided by continuous sensors might overwhelm patients and parents of young kids with type 1 diabetes. He suggested that it may be simpler from a clinical perspective to encourage development of a closed-loop sensor and pump immediately rather than offering continuous sensors and trying to train patients to interpret the data and make decisions. Dr. Wilson also noted that if such a system were built and were capable of keeping blood sugars out of the very low range, the current sensors, which have reduced accuracy in the low range, would be sufficient.
- Bruce Buckingham, MD, spoke about Hypoglycemia Detection, and Better Yet, Prevention, in Pediatric Patients, covering his work as a DirecNet study center. One interesting point was that on sedentary days, 28% of kids in trials experienced lows at night, while on active days, 52% of kids in trials experienced a low at night. That's a lot of nighttime hypoglycemia and much of it would not have been detected without the use of the continuous sensors under study by DirecNet.
- Bruce Bode, MD, and Jen Block, RN, CDE, offered Demonstrations and Discussions of Continuous Glucose Monitors as the final sessions on Friday. Jen Block presented videos showing the use of the Medtronic MiniMed CGMS Gold and Abbott Diabetes Care FreeStyle Navigator systems, stressing how easy these were to use. Dr. Bode showed CGMS tracings of a woman who experienced a large rise in blood sugar due only to black coffee, something that patients have noted for some time. (He recommended bolusing to cover the black coffee and that was effective.) Some of Dr. Bode's presentations are online at his web site. During the question and answer session, a veterinarian in the audience commented about using super glue to hold down sensors on large farm animals, noting that if you were careful, only a small amount of fur came off when removing the probes.
- Steve Edelman, MD, opened Saturday's sessions with a talk about Incretin Therapy: What's Coming This Year. Dr. Edelman noted that in spite of many technical advances in the past 20 years that there has been essentially no change in the number of people achieving an A1c of under 7 mg/dl, the ADA goal. His talk focused on a newly discovered class of hormones called incretins, represented by such drugs as Symlin and Exenatide. These drugs have been shown to help patients with diabetes to lower their A1c without increasing the risk of hypoglycemia, and concurrently to lose weight. There is even research to see if Exenatide can stimulate beta cell regeneration in patients with type 1 diabetes.
- Satish Garg, MD, spoke about New Insulin Analogs. Noting that both type 2 and type 1 diabetes is on the rise (in the US, type 1 diabetes is increasing at 5% per year), Dr. Garg stressed the importance of initiating insulin therapy sooner in patients with type 2 diabetes. He also stressed the benefits of insulin analogs in treating anyone with diabetes, type 1 or type 2, due to reductions in the risk of hypoglycemia. Dr. Garg shared the challenges of using NPH insulin by noting that proper use of NPH requires it to be rolled 26 times and that without proper resuspension, bioavailability of NPH can vary as much as 5 to 214% (1/20th of expected dose to over twice expected dose). Dr. Garg also noted that many studies have shown that Lantus can be injected anytime during the day with no effect on A1c. Finally, Dr. Garg noted that patients at the Barbara Davis Center have been mixing Lantus and fast-acting insulin for some time, even though this practice is off label, with no apparent effect on blood sugar control.
- Three faculty members spoke about the importance of blood sugar control in the hospital setting: Jeff Joseph, DO, Greg Beilman, MD, and Robert Vigersky, MD. All presented convincing data that showed that patients with poor blood sugar control experienced significantly worse outcomes in both surgical and medical settings in the hospital, as well as in the ICU. The clear message for anyone with diabetes who is going to the hospital is that you must maintain blood sugar levels as close to normal as possible to minimize the risk of potentially serious or even life threatening complications.
- Jay Skyler, MD, provided an Update on Inhaled Insulin. After discussing each inhaled insulin product under development or study, Dr. Skyler presented data from several studies that showed that inhaled insulin was as effective as injected fast acting insulin (NovoLog or Humalog) in lowering blood sugar, and that the inhaled insulins had essentially the same action profile as the injected insulin. Dr. Skyler also spoke about the safety data, which shows no acute effect on lung function and also no long term effect on lung function. Addressing the question of increased production of insulin autoantibodies seen in people who use inhaled insulin compared with injections, Dr. Skyler noted that the levels of these antibodies are significantly lower than the levels of antibodies seen years ago in patients who used animal sourced insulin that was not highly purified. Summarizing the safety data, Dr. Skyler stressed that while all data to date shows no problems, more long term studies are needed. Finally, Dr. Skyler noted that in a study done with children with type 1 diabetes, all the kids in the study loved inhaled insulin and all switched from injections to the insulin pump after the study concluded because none wanted to return to frequent daily injections.
- Steven Feinstein, MD, presented an amazing session on Technologies to Noninvasively Monitor Surrogate Markers of Atherosclerosis. While this might not seem to be of importance for kids with type 1 diabetes, it is. Several recent studies have shown that even young kids with type 1 diabetes can have abnormal lipid profiles, putting them at increased risk for atherosclerosis. Using a new contrast medium. Dr. Feinstein showed video presentations of ultra sounds of the carotid artery for several patients, including people with diabetes. In all cases, serious obstructions were clearly visible. Dr. Feinstein talked about his success in using statins to reduce these obstructions, and also their effectiveness in reducing the thickness of the carotid intima media, which is a marker for atherosclerosis. Finally, Dr. Feinstein stressed the importance of getting a complete fractionaed lipid profile when analyzing blood lipids.
- Howard Wolpert, MD, and Jen Block, RN, CDE, discussed today's smart pumps, which they defined as pumps that know about insulin on board, offer bolus calculation assistance, and include alarms. Dr. Wolpert noted that the most common cause of hypoglycemia in pump users is stacked boluses -- that is, taking too much insulin for a correction or bolus because of not accounting for insulin that was recently taken. Today's smart pumps can help reduce that risk by taking into considering insulin on board when recommending correction boluses.
Dr. David Klonoff (right), organizer of the meeting, discusses a presentation with Dr. Satish Garg (left)
Dr. Bruce Buckingham spoke about the use of continuous sensors to detect and prevent hypoglycemia in kids
Jen Block, RN, CDE gave several presentations, including one about smart pumps
Dr. Steve Edelman spoke about incretins, a new kind of drug therapy for managing blood sugars
Dr. Bruce Bode answered questions after his presentation about continuous sensors
Dr. Jay Skyler spoke about the current status of inhaled insulins
Dr. Vigersky, Dr. Wilson, and Jen Block demonstrate a glucose sensor