title: Effects of Short-Term Acclimatization at the Summit of Mt. Fuji (3776 m) on Sleep Efficacy, Cardiovascular Responses, and Ventilatory Responses.
abstract: Horiuchi, Masahiro, Shiro Oda, Tadashi Uno, Junko Endo, Yoko Handa, and Yoshiyuki Fukuoka. Effects of short-term acclimatization at the summit of Mt. Fuji (3776 m) on sleep efficacy, cardiovascular responses, and ventilatory responses. High Alt Med Biol. 18:171-178, 2017.-We investigated the effects of a short period of acclimatization, at 3776 m on Mt. Fuji, on sleep parameters and related physiological responses. Physiological responses were assessed in seven healthy lowlander men during both daytime and sleep while at sea level (SL), as well as for three consecutive nights at high altitude (HA; 3776 m, day 1 [D1], D2, D3, and morning only of D4). Blood pressure variables, heart rate (HR), pulmonary ventilation (VE), and breathing frequency (Bf) progressively increased each day, with significant differences between SL and HA (p < 0.05, respectively). In contrast, end-tidal PCO2(PETCO2) progressively decreased each day with statistical differences between SL and D3 at HA (p < 0.05). During sleep at HA, mean arterial pressure (MAP) was stable, whereas it decreased during sleep at SL. Sleep efficacy, which was assessed by actigraphy, was linearly impaired with statistical differences between SL and D3 (p < 0.05). These impairments in sleep efficacy at HA were associated with higher MAP and HR, as well as lower Bf and PETCO2during the daytime (pooled data, p < 0.05, respectively). These results suggest that hypoxia-induced cardiovascular and ventilatory responses may be crucial contributors to changes in sleep efficacy at HA.
authors.affiliation: 1 Division of Human Environmental Science, Mt. Fuji Research Institute , Yamanashi, Japan .
authors.forename: Masahiro
authors.initials: M
authors.lastname: Horiuchi
authors.affiliation: 2 Department of Health and Welfare, School of Life Long Sport, Hokusho University , Hokkaido, Japan .
authors.forename: Shiro
authors.initials: S
authors.lastname: Oda
authors.affiliation: 1 Division of Human Environmental Science, Mt. Fuji Research Institute , Yamanashi, Japan .
authors.forename: Tadashi
authors.initials: T
authors.lastname: Uno
authors.affiliation: 1 Division of Human Environmental Science, Mt. Fuji Research Institute , Yamanashi, Japan .
authors.forename: Junko
authors.initials: J
authors.lastname: Endo
authors.affiliation: 1 Division of Human Environmental Science, Mt. Fuji Research Institute , Yamanashi, Japan .
authors.forename: Yoko
authors.initials: Y
authors.lastname: Handa
authors.affiliation: 3 Faculty of Health and Sports Science, Doshisha University , Kyoto, Japan .
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Fukuoka
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000328:Adult; D000531:Altitude; D000532:Altitude Sickness / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology; D002320:Cardiovascular Physiological Phenomena; D064368:Healthy Volunteers; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009051:Mountaineering / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000502:physiology; D012119:Respiration; D012890:Sleep / Q000502:physiology*; D013997:Time Factors
keywords: acute mountain sickness; hypertension; hyperventilation; sleep disturbance