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NASA NTRS · 20040112332

Microgravity reduces sleep-disordered breathing in humans

Elliott, A. R.·Shea, S. A.·Dijk, D. J.·Wyatt, J. K.·Riel, E.·Neri, D. F.·Czeisler, C. A.·West, J. B.·Prisk, G. K.
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Abstract

To understand the factors that alter sleep quality in space, we studied the effect of spaceflight on sleep-disordered breathing. We analyzed 77 8-h, full polysomnographic recordings (PSGs) from five healthy subjects before spaceflight, on four occasions per subject during either a 16- or 9-d space shuttle mission and shortly after return to earth. Microgravity was associated with a 55% reduction in the apnea-hypopnea index (AHI), which decreased from a preflight value of 8.3 +/- 1.6 to 3.4 +/- 0.8 events/h inflight. This reduction in AHI was accompanied by a virtual elimination of snoring, which fell from 16.5 +/- 3.0% of total sleep time preflight to 0.7 +/- 0.5% inflight. Electroencephalogram (EEG) arousals also decreased in microgravity (by 19%), and this decrease was almost entirely a consequence of the reduction in respiratory-related arousals, which fell from 5.5 +/- 1.2 arousals/h preflight to 1.8 +/- 0.6 inflight. Postflight there was a return to near or slightly above preflight levels in these variables. We conclude that sleep quality during spaceflight is not degraded by sleep-disordered breathing. This is the first direct demonstration that gravity plays a dominant role in the generation of apneas, hypopneas, and snoring in healthy subjects.

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short durationNASA Experiment Number 9301198Non-NASA CenterSTS-95 Shuttle ProjectSTS-90 Shuttle ProjectmannedNASA Discipline Regulatory PhysiologyFlight ExperimentWeightlessnessSpace FlightSleep/physiologyRespirationAdultHumanPolysomnographyMaleSupport, U.S. Gov't, P.H.SSleep Disorders/physiopathologyFemaleSleep DeprivationSupport, U.S. Gov't, Non-P.H.S

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Elliott, A. R., Shea, S. A., Dijk, D. J., Wyatt, J. K., Riel, E., Neri, D. F., Czeisler, C. A., West, J. B., Prisk, G. K.. 2001-08-01. Microgravity reduces sleep-disordered breathing in humans. https://ntrs.nasa.gov/citations/20040112332

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