Sleep, breathing, arousals and oxygen saturation for one night at near sea level and three nights at high altitude
| Baseline | Altitude-1 (immediately after ascent to altitude) | Altitude-2 (1 week after ascent to altitude) | Altitude-3 (2 weeks after ascent to altitude) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Variable | Mean (SD) | Mean (SD) | Difference: effect sizewith 90% CL | Chances that value is greater/similar/lower than baseline value (%) | Mean (SD) | Difference: effect sizewith 90% CL | Chances that value is greater/similar/lower than baseline value (%) | Mean (SD) | Difference: effect sizewith 90% CL | Chances that value is greater/similar/lower than baseline value (%) |
| Time in bed (h) | 9.3 (0.9) | 9.0 (0.7) | −0.29 −0.48;−0.10 | 0/96/4 | 9.4 (1.4) | −0.02 −0.63; 0.58 | 7/84/9 | 8.7 (1.1) | −0.60 −1.11;−0.08 | 0/37/63 |
| Total sleep Time (h) | 8.0 (0.7) | 7.4 (0.8) | −0.62 −0.95;−0.30 | 0/25/74 | 8.0 (1.1) | −0.01 −0.59; 0.58 | 7/85/8 | 7.7 (0.9) | −0.31 −0.78; 0.16 | 1/75/24 |
| Sleep onset latency (min) | 18 (8) | 14 (7) | −0.22 −0.56; 0.11 | 0/92/8 | 23 (19) | 0.12 −0.39; 0.63 | 10/87/3 | 12 (8) | −0.58 −0.94;−0.22 | 0/35/65 |
| Stage N1 (min) | 26 (13) | 26 (13) | 0.12 −0.31; 0.55 | 7/92/1 | 25 (10) | −0.01 −0.61; 0.59 | 8/84/8 | 20 (7) | −0.39 −0.88; 0.10 | 0/65/35 |
| Stage N2 (min) | 216 (28) | 215 (37) | −0.04 −0.27; 0.19 | 0/100/0 | 245 (73) | 0.42 −0.29; 1.13 | 42/56/2 | 216 (41) | −0.04 −0.56; 0.47 | 4/89/7 |
| Stage N3 (min) | 130 (19) | 114 (27) | −0.63 −1.02;−0.24 | 0/28/72 | 117 (29) | −0.50 −1.00; 0.00 | 0/50/50 | 120 (24) | −0.39 −0.79;−0.01 | 0/71/29 |
| Stage R (min) | 107 (25) | 88 (19) | −0.82 −1.33;−0.32 | 0/14/86 | 93 (21) | −0.59 −1.28; 0.10 | 1/40/59 | 106 (17) | −0.01 −0.52; 0.50 | 5/89/6 |
| Wake after sleep onset (min) | 64 (39) | 81 (34) | 0.58 −0.05; 1.21 | 59/40/1 | 59 (32) | −0.04 −0.77; 0.69 | 10/76/14 | 47 (31) | −0.51 −1.17; 0.16 | 1/48/51 |
| Sleep efficiency (%) | 86 (5) | 82 (6) | −0.56 −1.21; 0.09 | 1/42/57 | 86 (5) | 0.03 −0.78; 0.83 | 15/71/13 | 89 (4) | 0.57 0.04; 1.09 | 59/41/0 |
| Respiratory disturbance Index (h−1) | 1 (1) | 30 (39) | 1.19 0.67; 1.71 | 98/2/0 | 45 (57) | 1.34 0.78; 1.90 | 100/0/0 | 34 (41) | 1.26 0.73; 1.79 | 99/1/0 |
| Central apnoeas (count) | 8 (7) | 142 (216) | 0.70 0.25; 1.16 | 78/21/0 | 285 (451) | 0.78 0.19; 1.37 | 80/20/0 | 177 (231) | 0.86 0.36; 1.34 | 89/11/0 |
| Hypopneas (count) | 2 (2) | 92 (101) | 1.81 1.26; 2.37 | 100/0/0 | 110 (114) | 1.95 1.40; 2.50 | 100/0/0 | 98 (109) | 1.92 1.45; 2.39 | 100/0/0 |
| Periodic breathing (%) | 0 (0) | 13 (18) | 0.91 0.38; 1.44 | 90/9/0 | 24 (32) | 0.99 0.33; 1.65 | 90/10/0 | 21 (28) | 0.95 0.31; 1.58 | 88/11/0 |
| Total arousals (count) | 88 (27) | 143 (68) | 0.58 0.27; 0.90 | 68/32/0 | 293 (303) | 1.07 0.27; 1.86 | 89/11/0 | 144 (92) | 0.53 0.11; 0.94 | 55/45/0 |
| Spontaneous arousals (count) | 86 (28) | 83 (44) | −0.20 −0.64; 0.24 | 1/87/12 | 75 (76) | −0.59 −1.17;−0.01 | 0/39/61 | 72 (44) | −0.47 −1.05; 0.12 | 1/53/46 |
| Respiratory arousals (count) | 2 (3) | 60 (84) | 0.89 0.47; 1.31 | 94/6/0 | 155 (290) | 0.97 0.40;1.53 | 92/8/0 | 72 (108) | 0.90 0.38; 1.42 | 90/10/0 |
| Mean SpO2 (%) | 97 (1) | 82 (3) | −5.84 −6.52;−5.16 | 0/0/100 | 86 (3) | −4.06 −4.47;−3.42 | 0/0/100 | 88 (1) | −3.41 −3.64;−3.18 | 0/0/100 |
| Minimum SpO2 (%) | 93 (2) | 74 (4) | −3.73 −4.23;−3.23 | 0/0/100 | 77 (6) | −3.13 −3.98;−2.28 | 0/0/100 | 80 (3) | −2.37 −2.71;−2.03 | 0/0/100 |
| Desaturations >3% (count) | 3 (3) | 214 (283) | 1.55 1.07; 2.03 | 100/0/0 | 329 (407) | 1.79 1.28; 2.29 | 100/0/0 | 256 (305) | 1.75 1.30; 2.20 | 100/0/0 |
Variables related to sleep, breathing, arousals and oxygen saturation for one night at near sea level (baseline) and three nights at high altitude (altitude-1, altitude-2 and altitude-3). For each night, data are presented as means (±SD). For each night at altitude, data are also presented as standardised differences from baseline (ie, effect size with 90% CL), and the chances that an observed value is greater/similar/lower than the corresponding baseline value are given. Baseline occurred 1–2 nights before ascent to high altitude, altitude-1 occurred 1–2 nights after ascent, altitude-2 occurred 6–7 nights after ascent and altitude-3 occurred 12–13 nights after ascent.