Technology Conference Highlights the Future of Diabetes Care

Potential changes help patients and doctors alike

By Daniel Trecroci

On October 25-27, 2007, the brightest minds in diabetes technology descended upon the Bay Area for a three-day conference.

Here are some of the highlights:

Measuring Glucose with Infrared Technology

At an October 25th workshop, Orna Amir, Ph.D. of OrSense Ltd. did a presentation on "Noninvasive Continuous Glucose Monitoring Based on Occlusion Spectroscopy." OrSense's device uses transmission-based, red-near infrared light to continuously monitor blood glucose. Data were presented supporting the potential use of OrSense's device as a noninvasive sensor for continuous blood glucose monitoring. In addition to showing acceptable accuracy, the device was safe, painless, and well tolerated.

Measuring Glucose in the Eye

On the same day, Brent Cameron, Ph.D. from the Department of Bioengineering at the University of Toledo in Toledo, Ohio, presented "Advances in Optical Polarimetry for Noninvasive Glucose Sensing." Cameron discussed possibilities for the eventual development of a non-invasive testing device that measures glucose by shining a light in the eye. Cameron's theory is that the glucose can be measured in the liquid aqueous humor portion of the eye.

Working Toward an Artificial Pancreas

On October 26th, Robert Mah, Ph.D. of NASA Ames Research Center in Mountain View, California, presented "Closed Loop Control: Is It Rocket Science?" According to Amy Tenderich, a closed-loop device (or "artificial pancreas) is one that combines continuous blood-glucose sensing and insulin delivery. Mimicking the function of the human pancreas, a "closed-loop" system monitors glucose levels and, in response, delivers an appropriate amount of insulin. In his presentation, Mah specified that closed-loop control for insulin delivery can be quite sophisticated to improve performance. In any case, he states, good sensors are the key to its effectiveness.

Computerized Safety for ICU Patients

The same day, Geoffrey Chase, Ph.D. of the University of Canterbury in Christchurch, New Zealand, discussed "Intensive Insulin Therapy and the Artificial Pancreas in Critical Care: Pitfalls, Practicalities and Performance." Chase presented the results of his team's SPRINT Glycemic Control protocol, which uses a simple algorithm based on more complex, computerized methods to balance insulin and nutritional inputs to ICU patients on a one to two-hour basis. The goal is to ensure tight control to within a 72-110 mg/dL (4-6.1 mmol/L) range for the patient's entire stay, which is typically 100+ hours.

"Overall, mortality was reduced 20 to 35 percent for patients in ICU for longer than three to five days—over 50 percent in our cohort—in a 1.5-year trial compared to retrospective patients," says Chase.

System Keeps Diabetes Professionals on Task

On October 27th, COL Robert Vigersky, M.D. U.S. Army, Walter Reed Army Medical Center talked about "Computer Assisted Decision Support (CADS) for Primary Care of Diabetes." Vigerksy says that the explosive growth in the number of diabetes therapies makes it extremely difficult for diabetes professionals to maintain familiarity with available options and algorithms. Vigersky says that a CADS system using data from memory meters, current medications and clinical practice guidelines would be expected to improve quality of care. Vigersky's team has developed a CADS system prototype, which automatically interprets glucose profiles, prioritizes problem areas, and recommends changes in existing treatments. The CADS system receives input from:

• An on-line patient module in which glucose data are uploaded, and medication history, schedule for glucose monitoring, and meal times are verified.

• A customizable administrator module, which includes formulary information, a set of regimens, and rules for warnings.

• A customizable provider module, which sets treatment goals, target glucose ranges and glucose-monitoring schedules. This module displays the data analysis and recommended changes in treatment.

Rapid-Acting Insulin Mimics Insulin Production of Nondiabetics

Also on the 27th, Andreas Pftzner, M.D., Ph.D. from the Institute of Clinical Research and Development in Mainz, Germany, presented data from "Mealtime Glycemic Control Comparing VIAject™ to Lispro." VIAject™ is a very rapid-acting form of injectable human insulin for meal-time use by patients with type 1 or type 2 diabetes. VIAject™ is made up of regular human insulin and a formulation of other ingredients that are "generally regarded as safe" by the Food and Drug Administration. The insulin is more rapidly absorbed to mimic the effects of naturally produced insulin in people without diabetes. Viaject™ is presently in Phase II clinical studies.

For a complete listing of all of the topics from the Diabetes Technology Meeting, log on to http://www.diabetestechnology.org.

Read Daniel Trecroci's bio.

Read more of Daniel Trecroci's columns.

NOTE: The information is not intended to be a replacement or substitute for consultation with a qualified medical professional or for professional medical advice related to diabetes or another medical condition. Please contact your physician or medical professional with any questions and concerns about your medical condition.

http://www.nsbri.org/newsflash/indivArticle.asp?id=454&articleID=90

520-Day Mars Mission Simulation: U.S. study looks at impact of stress and fatigue on performance

6/3/2010

Ever wondered what it would be like to go on a mission to Mars?

On June 3, a six-man international crew entered an isolation chamber in Moscow for a simulated 520-day Mars mission conducted by the State Scientific Center of the Russian Federation -- Institute for Biomedical Problems (IBMP) of the Russian Academy of Sciences. The crew has a mission schedule full of more than 90 experiments and realistic scenarios, including emergency situations, 20-minute communications delays and a trip to the martian surface.

The specialized IBMP facility consists of interconnected modules serving as the mock interplanetary spaceship, including medical and scientific research areas, living quarters, a kitchen, greenhouse and exercise area. The chamber also contains a Mars landing vehicle module and a martian landscape module for simulated extravehicular activities.

Supported by National Space Biomedical Research Institute (NSBRI), the U.S. scientific team participating in the study is monitoring the six crew members' rest-activity cycles, performance and psychological responses to determine the extent to which sleep loss, fatigue, stress, mood changes and conflicts occur during the mission.

"Extensive data from the Russian Mir Space Station, International Space Station and Apollo missions suggest that psychological and behavioral issues will be perhaps the greatest challenge humans will face when they embark on years-long missions to Mars and other locations," said David F. Dinges, Ph.D., leader of the NSBRI-funded group and a professor of psychology in psychiatry at the University of Pennsylvania School of Medicine.

The 520-day Mars Mission, conducted by IMBP under the auspices of the Russian Space Agency (Roscosmos), the Russian Academy of Sciences, and in cooperation with the European Space Agency, is the final phase of the Russian Mars 500 program. Previous phases included a 14-day test of the facility and a 105-day isolation study involving a six-man international crew in 2009. The 520-day mission is broken into 250 days for the trip to Mars, 30 days on the surface, and 240 days for the return to Earth.

During the simulation, Dinges and his colleagues are using miniaturized wristwatch-like devices to measure crew members' sleep-wake patterns and specially programmed computers with brief assessment tests to gather information throughout the mission on crew members' performance and emotions. Dinges is working in collaboration with Matthias Basner, M.D., from Penn, Dimitris Metaxas, Ph.D., of Rutgers University, and Daniel Mollicone, Ph.D., of Pulsar Informatics, Inc. Igor Savelev, Ph.D., NSBRI's International Liaison, oversees the onsite implementation of the study and works in coordination with the Dinges team.

A key component of the computer-based assessment is the Psychomotor Vigilance Task (PVT) Self Test. This three-minute test measures the stability of sustained attention, psychomotor speed and impulsivity. PVT Self Test is also undergoing evaluation on the space station, where it is known as the Reaction Self Test.

"We've learned from laboratory experiments, other mission analogs and the Russian's 105-day isolation study that the PVT is sensitive to fatigue and other factors that degrade the ability to pay attention and respond quickly," said Dinges, who leads NSBRI's Neurobehavioral and Psychosocial Factors Team.

PVT Self Test was developed through Dinges' work with NSBRI, NASA, the Department of Defense and the National Institutes of Health. The user watches for a signal and responds when it appears, allowing the measurement of reaction times at a high degree of precision. Dinges also implemented PVT in studies involving astronauts in other space analog environments, such as on the ocean floor in NASA's Extreme Environment Mission Operations (NEEMO) program.

"As soon as he completes the PVT Self Test, the crew member receives an assessment of how well the task was performed relative to someone who is fully alert and capable. The report also indicates how many times responses were too slow and how many times responses occurred before the signal came on," Dinges said. "So, there is a measure of impulsivity as well as fatigue."

Crew members do the assessment tests on their own specialized laptops programmed by Pulsar Informatics with built-in cameras to record facial expressions during testing. Facial video data will be evaluated off-line by computer algorithms developed in the Metaxas laboratory, where an optical computer recognition system is being created and validated in collaboration with Dinges for use in space to unobtrusively detect signs of sleepiness, negative moods and stress.

Every seventh day of the Mars 520-day mission simulation, the assessment tests are completed in the morning and before sleep. The tests take 10 minutes, requiring only 20 minutes of the crew member's time on testing day, and include PVT Self Test and other measures of sleep quality/quantity, fatigue, stress, moods, conflict and depression.

"The crew is on a six-day work week. Because they take the test every seven days, we will get data from every day of their work cycle 14 times throughout the mission," Dinges said.

For Dinges, the need to obtain data in this type of environment is essential.

"This simulated Mars mission is by far the longest-duration study of crew confinement under operating conditions attempted to date. It will have an impact on planning for exploration missions," Dinges said. "It provides something we can't learn from much shorter-duration simulations or from the 180-day stays on the space station: namely, what is the effect on crews of living and working for 520 days in continuous confinement?"

Mars 500 will allow Dinges and others to find out whether the ability to sleep well, attend to tasks, react quickly, maintain positive moods, and feel alert is sustainable across such a long mission, and whether there is evidence of negative moods, depression and an increase in conflicts.

The lessons learned extend to life on Earth. "These tests and interventions have an impact beyond the space program," said Dinges, a 2007 recipient of the NASA Distinguished Public Service Medal. "Many people, including those in military operations and many first responders, work night shifts and in high-stress, often confined environments that require alertness. The things we are learning about how to objectively and unobtrusively measure changes in performance and psychological status will be useful in many environments, such as power plant control rooms, railroad systems, emergency operations, hospitals, and police, fire and rescue situations."

Detailed summary of the Dinges/NSBRI project

 http://www.brighamandwomens.org/about_bwh/publicaffairs/news/pressreleases/PressRelease.aspx?sub=0&PageID=1117

Less Sleep, Disrupted Internal 24-hour Clock Means Higher Risk of Diabetes and Obesity

A study by researchers at Brigham and Women's Hospital (BWH) reinforces the finding that too little sleep or sleep patterns that are inconsistent with our body's "internal biological clock" may lead to increased risk of diabetes and obesity. This finding has been seen in short-term lab studies and when observing human subjects via epidemiological studies. However, unlike epidemiological studies, this new study provides support by examining humans in a controlled lab environment over a prolonged period, and altering the timing of sleep, mimicking shift work or recurrent jet lag.

The study will be electronically published on April 11, 2012 in Science Translational Medicine.

Researchers hosted 21 healthy participants in a completely controlled environment for nearly six weeks. The researchers controlled how many hours of sleep participants got, as well as when they slept, and other factors such as activities and diet. Participants started with getting optimal sleep (approximately 10 hours per night). This was followed by three weeks of 5.6 hours of sleep per 24-hour period and with sleep occurring at all times of day and night, thereby simulating the schedule of rotating shift workers. Thus, during this period, there were many days when participants were trying to sleep at unusual times within their internal circadian cycle-the body's "internal biological clock" that regulates sleep-wake and many other processes within our bodies. The study closed with the participants having nine nights of recovery sleep at the usual time.

The researchers saw that prolonged sleep restriction with simultaneous circadian disruption decreased the participants' resting metabolic rate. Moreover, during this period, glucose concentrations in the blood increased after meals, because of poor insulin secretion by the pancreas.

According to the researchers, a decreased resting metabolic rate could translate into a yearly weight gain of over 10 pounds if diet and activity are unchanged. Increased glucose concentration and poor insulin secretion could lead to an increased risk for diabetes.

"We think these results support the findings from studies showing that, in people with a pre-diabetic condition, shift workers who stay awake at night are much more likely to progress to full-on diabetes than day workers," said Orfeu M. Buxton, PhD, BWH neuroscientist and lead study author. "Since night workers often have a hard time sleeping during the day, they can face both circadian disruption working at night and insufficient sleep during the day. The evidence is clear that getting enough sleep is important for health, and that sleep should be at night for best effect."

This research was supported by the National Institute on Aging;  National Heart, Lung and Blood Institute; National Center for Research Resources; Center for Clinical Investigation of the Harvard Clinical and Translational Science Center; Joslin Diabetes and Endocrinology Research Center Service Specialized Assay Core; the National Space Biomedical Research Institute; and Natural Sciences and Engineering Research Council of Canada.

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