Glenn: So far, no ill effects from space

Senator will continue in 'guinea pig' role.

Scripps Howard News Service

WASHINGTON -- Sen. John Glenn expects to continue his role as a guinea pig for some time, but the results of his return to space at age 77 are beginning to trickle in, scientists told a conference on aging research Tuesday. Researchers still are analyzing data on Glenn's sleep patterns, muscle tone, bone strength and several other biological tests done during his 10 days aboard the space shuttle Discovery last fall. Most results won't be available until later this year, but scientists involved in the studies indicated so far nothing has been detected that they didn't expect to find in someone of advanced age. In days and weeks of the zero gravity of space, astronauts experience many of the physiologic changes that also accompany aging -- loss of muscle mass and tone, loss of bone mass, loss of balance and spatial orientation, and sleep disruption. The difference, though, is that most of the deterioration in space is reversed or at least halted when the astronauts return to Earth. "We're getting a better handle on these effects of long-term space flight and what turns them off and on," Glenn told a briefing sponsored by the American Federation of Aging Research. "Perhaps at sometime in the future we can use this knowledge to turn off many of the frailties of old age that plague us now." Glenn's hypothesis -- that a person who has already experienced some of the effects of aging should be somewhat adapted to the effects of space flight -- seems to have been borne out to some extent:- Glenn and his six fellow crew members recovered their balance and ability to walk within four days, a better than average bounce-back time. NASA scientists have noticed that space veterans tend to be able to readjust to gravity more quickly than rookies, apparently because brain receptors somehow become wired for the changes, said Dr. Owen Black, head of the Neurology Research Laboratory at the Legacy Holladay Park Medical Center in Portland, Ore., and a NASA consultant. "You might think of Glenn as a veteran, but because he was strapped in for his entire five hour flight in 1962, he really was more like a rookie when it came to being weightless. So he's a good test for whether adaptive control can take place in someone in their eighth decade," Black said. On the ground, researchers are developing equipment that helps the elderly regain their equilibrium in hopes of eliminating more than 200,000 serious falls among seniors every year. - Although the former senator and ex-Marine test pilot never gets airsick, he had feared the motion sickness that plagues about half of all astronauts in their first hours in space. He didn't get it. But after overloading fluids in preparation for a return to Earth, he wasn't so lucky back on the ground. Still, Glenn said he felt he had completely recovered his muscle tone and "felt great" after his first few days back on Earth. Dr. William Evans of the University of Arkansas for Medical Sciences and the VA Medical Center in North Little Rock said research and therapy involving muscle loss in the elderly is actually leading the way to possible steps that could keep astronauts robust on a three-year round-trip to Mars, for instance. While most seniors don't jog two miles a day like Glenn, Evans said the modest free weight lifting he also does is probably the best way to offset the decline of muscles found in more and more elderly as they age. - Also unlike most seniors, Glenn has little trouble sleeping, although he augments any sleep he loses with naps. He doesn't think he had much difficulty snoozing in space, either. "I wound up sleeping about 11/2 hours less a night than I do at home, but I have the same problem when I don't do my exercise routine. I think the reduced activity load in zero gravity just left me that much less tired." Dr. Charles Czeisler, a sleep disorder specialist at Harvard Medical School and Brigham and Women's Hospital in Boston, who set up the sleep experiments with Glenn, said the senator's strategy of napping helps him get around what researchers have found is a "narrowed window of opportunity for deep sleep" experienced by many elderly people.

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