Table 2. Effect of altitude on the apnea hypopnea index.
| Manuscripts | Altitude MAMSL | n | AHI h −1 mean/median ± SD/IR | CAI h −1 mean/median ± SD/IR | OAI h −1 mean/median ± SD/IR | Evaluation method | |
|---|---|---|---|---|---|---|---|
| Healthy persons | |||||||
| Bloch et al., 2010 10 | 490 (basal) | 34 | 4.0 (1.2–9.7) | NR | NR | RP | |
| 4,497 | 32 | 71.9 (37.2–96.2) * | NR | NR | |||
| 5,533 | 29 | 114.1 (81.1–130.3) * | NR | NR | |||
| 6,265 | 24 | 142.6 (120.4–154.2) * | NR | NR | |||
| 6,865 | 24 | 132.3 (103.3–157.4) * | NR | NR | |||
| Latshang et al., 2013 15 | 490 (Basal) | 51 | 4.6 (2.3–7.9) | 2.0 (1.2–3.7) | 1.3 (0.3–4.6) | PSG | |
| 2,590 (1 st night) | 13.1 (6.7–32.1) * | 8.9 (5.0–25.8) * | 1.8 (0.7–3.8) | ||||
| 2,590 (2 nd night) | 8.0 (4.4–23.1) * ^ | 5.8 (2.8–13.1) * ^ | 1.6 (0.7–3.4) | ||||
| Lombardi et al., 2013 16 | M | F | |||||
| Sea level (basal) | 37 | 0.03 ± 0.11 | 0.14 ± 0.21 | NR | NR | RP | |
| 3,400 | 36 | 2.4 ± 2.8 * | 40.3 ± 33.0 * & | NR | NR | ||
| 5,400 (1 st /2 nd night) | 24 | 41.1 ± 44 * | 87.5 ± 35.7 * & | NR | NR | ||
| 5,400 (10 th night) | 28 | 84.7 ± 22.5 * | 97.0 ± 30.3 * & | NR | NR | ||
| Heinzer et al., 2016 19 # | 485 (NN, basal) | 13 | 8.2 (3.9–8.8) | NR | NR | PSG | |
| 3,450 (NH) | 11.4 (5.0–65.4) * | NR | NR | ||||
| 3,450 (HH) | 20.5 (15.8–57.4) * | NR | NR | ||||
| Pramsohler et al., 2017 21 # | 5,500 | 11 | 143.1 (24.6–168) | NR | NR | PSG | |
| Pramsohler et al., 2019 23 # | 3,500 (basal) | 11 | 37.96 | NR | NR | PSG | |
| 4,500 | 68.55 * | NR | NR | ||||
| 5,500 | 93.44 * | NR | NR | ||||
| Frost et al., 2021 25 | 340 (basal) | 15 | 4.3 (4.5) | 0.5 (0.6) | 0.5 (1.1) | RP | |
| 3,800 (1 st night) | 35.3 (28.7) * | 14.0 (17.1) | 0.3 (0.8) | ||||
| 3,800 (2 nd night) | 16.0 (21.1) | 7.6 (15.2) | 0.1 (0.2) | ||||
| 3,800 (3 rd night) | 7.3 (5.3) | 0.8 (0.8) | 0.1 (0.2) | ||||
| Ju et al., 2021 26 | 154 (basal) | 10 | 1.4 (0.8–3.0) | NR | NR | RP | |
| 2,761 | 10.3 (5.7–15.4) * | NR | NR | ||||
| Bird et al., 2021 27 | Rapid ascent | RP | |||||
| 1,130 (basal) | 21 | 3.4 ± 3.5 | NR | NR | |||
| 3,800 (2 nd night) | 20 | 12.3 ± 14.5 * | NR | NR | |||
| 3,800 (9 th night) | 20 | 24.6 ± 23.7 * | NR | NR | |||
| Incremental ascent | |||||||
| 1,130/1,400 (basal) | 21 | 3.7 ± 4.1 | NR | NR | |||
| 3440 (2 nd /3 th night) | 19 | 10.8 ± 11.8 | NR | NR | |||
| 4240 (6/7 th night) | 14 | 26.7 ± 17.8 * | NR | NR | |||
| 5160 (9/10 th night) | 15 | 39.2 ± 32.6 * | NR | NR | |||
| Patients with chronic obstructive pulmonary disease | |||||||
| Tan et al., 2020 24 | 490 (basal) | 32 | 22.0 ± 15.8 | 1.6 ± 1.9 | 20.4 ± 15.2 | PSG | |
| 2048 | 44.0 ± 35.8 * | 32.4 ± 32.3 * | 11.6 ± 13.2 * | ||||
| Patients with obstructive sleep apnea syndrome | |||||||
| Nussbaumer-Ochsner et al., 2010 11 | 490 (basal) | 40 | 51.2 (31.7–74.4) | 2.4 (0.4–8.8) | 21.0 (16.4–24.9) | PSG | |
| 2590 (1 st night) | 90.0 (64.2–103.2) * | 51.3 (32.8–75.5) * | 32.0 (3.3–54.6) | ||||
| 2,590 (2 nd night) | 88.6 (62.4–108.4) * | 49.4 (22.6–57.8) * | 25.2 (6.5–58.8) | ||||
| Pagel et al., 2011 12 | 2,165 | 142 | 46.7 ± 26.8 | 15.8 | 30.9 | PSG | |
| Nussbaumer-Ochsner et al., 2012 14 | 490 (basal) | 45 | 51.2 (42.4– 72.2) | 1.6 (0.5– 3.2) | 49.4 (41.4– 67.6) | PSG | |
| 2590 | 86.2 (67.2–103.1) * | 23.4 (14.0–44.5) * | 55.5 (34–75.0) | ||||
| Ulrich et al., 2014 17 | 490 (Basal) | 18 | 57.3 (46.5–67.3) | 0.8 (0.2–1.8) | 49.6 (42.2–62.2) | PSG | |
| 2,590 | 86.5 (70–117) | 30.7 (21.2–48.2) * | 61.3 (33.9–75.0) | ||||
Abbreviations: AHI, apnea hypopnea index, CAI, central apnea index, COPD, chronic obstructive pulmonary disease, F, female, h-1, events per hour, HH, hypobaric hypoxia, IR, interquartile range, M, male, MAMSL, meters above sea level, NH, normobaric hypoxia, NN, normobaric normoxia, NR, not reported, OAI, obstructive apnea index, PSG, polysomnography, RP, respiratory polygraphy, SD, standard deviation.
*
p < 0.05 vs. Basal.
^
p < 0.05 vs 1 st night.
&
p < 0.05 males vs females.
#
Studies conducted with simulated altitude.