Abstract
Reports that aging slows down in space prompted this investigation of anti-aging effects in humans by analyzing astronauts’ heart rate variability (HRV). Ambulatory 48-hour electrocardiograms from 7 astronauts (42.1 ± 6.8 years; 6 men) 20.6 ± 2.7 days (ISS01) and 138.6 ± 21.8 days (ISS02) after launch were divided into 24-hour spans of relative lower or higher magnetic disturbance, based on geomagnetic measures in Tromso, Norway. Magnetic disturbances were significantly higher on disturbed than on quiet days (ISS01: 72.01 ± 33.82 versus 33.96 ± 17.90 nT, P = 0.0307; ISS02: 71.06 ± 51.52 versus 32.53 ± 27.27 nT, P = 0.0308). SDNNIDX was increased on disturbed days (by 5.5% during ISS01, P = 0.0110), as were other HRV indices during ISS02 (SDANN, 12.5%, P = 0.0243; Triangular Index, 8.4%, P = 0.0469; and TF-component, 17.2%, P = 0.0054), suggesting the action of an anti-aging or longevity effect. The effect on TF was stronger during light (12:00–17:00) than during darkness (0:00–05:00) (P = 0.0268). The brain default mode network (DMN) was activated, gauged by increases in the LF-band (9.7%, P = 0.0730) and MF1-band (9.9%, P = 0.0281). Magnetic changes in the magnetosphere can affect and enhance HRV indices in space, involving an anti-aging or longevity effect, probably in association with the brain DMN, in a light-dependent manner and/or with help from the circadian clock.
Original language | English (US) |
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Article number | 8995 |
Journal | Scientific reports |
Volume | 9 |
Issue number | 1 |
DOIs | |
State | Published - Dec 1 2019 |
Bibliographical note
Funding Information:The authors thank Dr. I. Tayama, T. Aiba and S. Ishida from the Space Biomedical Research Group, Japan Aerospace Exploration Agency (JAXA), for cooperation in our study. The authors also acknowledge the cooperation of the astronauts, the engineers, staff and managers of JAXA and NASA. The help of Larry A. Beaty to improve the English language for greater clarity and readability is greatly appreciated. JAXA Chronobiology Project was supported by the Japan Aerospace Exploration Agency (K.M., H.O., S.F., C.M.) and Halberg Chronobiology Fund (G.C.).
Publisher Copyright:
© 2019, The Author(s).