Skip to main content

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.