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Table 2 Study design

From: The physiological effects of hypobaric hypoxia versus normobaric hypoxia: a systematic review of crossover trials

Author and year Type of outcome variable Population PiO 2 of exposure (calculated by PiO 2 = (Pb-47) × FiO 2 [4]) (mmHg) Duration of exposure (h:min) Randomised (Y, N) Washout period between trials (days:h)
NH HH
Basualto-Alarcon 2012 Ventilatory and cardiovascular + exercise 7 men 3,000 mc 3,000 mc 00:15 builda, 00:10 N 7
Degache 2012 Postural stability 12 men 118 and 102 121 and 103 00:20–25 builda, 00:30b Nil stated <00:24
Hemmingsson 2009 Exhaled NO 6 men, 2 women 103 and 81 99 and 75 00:10 at each altitude Y <00:12
Loeppky 2005 Fluid balance 9 men 81 80 00:05 builda 10:00 Y 7
Loeppky 1997* Ventilatory and cardiovascular 9 men 81 80 00:05 builda 10:00 Y 7
Miyagawa 2010 Ventilatory, cardiovascular and sweat + exercise 7 men 93 97 00:30 builda only for HH 01:40 Y >6
Naughton 1995 Haematological + exercise 9 subjects with chronic airflow limitation (CAL) with 6 controls 1,829 and 2,438 mc 117 and 108 00:12 builda included 00:52:00 Y 00:02
Roach 1996 AMS and cardiovascular 9 men 4,564 mc 80 09:00 Y 7
Savourey 2003 Ventilatory and cardiovascular 18 men 4,500 mc 4,500 mc 00:10 builda, 00:30 Y 7
Savourey 2007 Ventilatory and cardiovascular 17 men, 1 woman 4,500 mc 4,500 mc 00:10 builda, 00:30 Y 14
Self 2011 AMS and cardiovascular 17 men and 3 women 7,620 mc 7,620 mc 00:05 N <00:24
Tucker 1983 Mixed 11 men 82 80 00:15 builda included 02:20 N Several weeks
Faiss 2013 Exhaled NO, ventilatory and cardiovascular + exercise 10 men 99 101 24:00:00 Y 23
  1. This table describes all the features of the accepted studies.
  2. aWhen the subjects entered the chamber, the environmental conditions were that of normal sea level but then were gradually made more hypoxic over the specified amount of time until the target hypoxic dose was reached.
  3. bThe different altitudes were tested consecutively. So sometimes the exposure was 1 h at 3,000 or 1,700 m.
  4. cWhen PiO2 could not be calculated due to lack of information, the equivalent attitude estimated by the authors was given.
  5. *P values were for three conditions; in recovery no P values unless stated in the discussion.