The Stanford Center on Longevity views the challenge of keeping people physically active throughout their lifespans as a priority. The goal is to understand and remove key barriers to movement, be they physical conditions or diseases, psychological barriers to exercise, or environmental obstacles.

One of the SCL’s most intriguing projects involves a device that, from the outside, looks like it could have come straight from the set of a science fiction movie. Dubbed “pods” by researchers, the giant egg-shaped devices are altitude simulators in which users sit and are exposed to changing levels of atmospheric pressure.

Originally, Dr. Anne Friedlander, who heads the SCL Mobility Division, was testing whether the pods could help athletes and military personnel acclimatize faster to altitude and to perform better physically at sea level and high altitude. A Plexiglas lid lifts up and users climb inside, where they sit in a comfortable seat and can read or rest while air pressure in the pod is rapidly increased and decreased.

However, while studying the pods, Dr. Anne Friedlander became intrigued with evidence that such changes in pressure levels when combined with the intermittent hypoxia – or reduction in oxygen resulting from reduced atmospheric pressure - might be triggering other metabolic effects. For example, anecdotal evidence suggested that test subjects were experiencing less joint pain and improved overall feelings of energy and health. Blood tests suggested that the pods might be producing measurable metabolic changes in the subjects, including reduction of blood glucose levels and higher testosterone in men. The impact on blood glucose was a particularly interesting finding for Dr. Friedlander, who maintains a laboratory at the U.S. Department of Veterans Affairs Palo Alto Health Care System (VAPAHCS). Diabetes, which is characterized by insulin resistance and abnormally high blood sugar levels, is a major complication of aging and afflicts almost 200 million people around the world.

In August 2008, Dr. Friedlander reported promising results from a controlled clinical trial in which male subjects between the ages of 40-60 were exposed to what is called the “CVAC process” (Cyclic Variations in Altitude Conditioning) for 40 minutes, three times a week for 10 weeks. The subjects demonstrated a significant reduction in fasting blood glucose and a significant decrease in blood glucose during an oral glucose tolerance test (OGTT) following the 10 weeks of exposure. There was no significant change in the control group.

"CVAC could provide a unique way to lower blood glucose levels in certain individuals," says Friedlander. "Given that these positive results were achieved in middle-aged, non-diabetic volunteers, we are hopeful that CVAC will prove even more effective in diabetic subjects with higher initial fasting glucose levels.”

Diabetic patients are a segment of the population that is prone to obesity and joint problems and could greatly benefit from increased exercise. Stabilizing glucose levels is one approach to improving these patients’ overall health and mobility. However, the next phase of Friedlander’s research with CVAC will look at a related problem with an even more direct impact on individual mobility: diabetic neuropathy, or pain associated with diminished circulation that is another side effect of high blood sugar levels. "We are excited about the potential for the CVAC process to produce an improvement in both the condition and quality of life for diabetes and diabetic neuropathy patients," added Dr. Friedlander. "We are still researching the mechanism, but if use of CVAC attenuates insulin resistance, it is possible that CVAC could also be useful in treating other disorders related to insulin resistance and the aging process."

Dr. Friedlander is analyzing the data and preparing the results for publication.