Table 4 Objective sleep measurements TST: total sleep time; WASO: wake after sleep onset; REM: Rapid eye movement; PLM: periodic leg movements; ODI: Oxygen desaturation index; AHI: apnea-hypopnea index.

Total sleep period (min)

421 [377; 461]

429 [371; 466]

408 [380; 458]

0.58

TST (min)

319 [264; 378]

325 [273; 398]

311 [244; 349]

0.12

WASO (%TST)

26.6 [15.6; 44.4]

24.5 [16; 40.4]

33 [14.8; 44.5]

0.56

Stage 1 (%TST)

14 [7.8; 24.7]

12.7 [7.9; 24.3]

14.3 [6.5; 25.9]

0.94

Stage 2 (%TST)

51.5 [42.2; 61.3]

51.1 [42.3; 59.5]

57.2 [42; 63.5]

0.49

Slow-wave sleep (%TST)

7.9 [0.3; 14.2]

9 [0.4; 13.8]

7.4 [0.3; 17]

0.89

REM Sleep (%TST)

20.6 [14.5; 26.2]

22.5 [14.7; 26.9]

19.2 [13.9; 21.9]

0.15

Microarousal index

25.8 [14.9; 38.5]

26 [14.8; 37.4]

25.8 [15.5; 39.7]

0.91

PLM during TST

0 [0; 34]

0 [0; 32.5]

7 [0; 35]

2 (2)

0.27

Central apnea index (/h TST)

0.5 [0; 1.6]

0.5 [0.1; 2.8]

0.5 [0; 1.2]

0.26

Central hypopnea index (/h TST)

2.1 [0.8; 4.9]

2.7 [0.9; 5.5]

1.6 [0.4; 3.2]

0.10

Obstructive apnea index (/h TST)

0.9 [0; 3.6]

0.6 [0; 3.1]

2 [0.2; 8.6]

0.04

Mixed apnea index (/h TST)

0 [0; 0.1]

0 [0; 0]

0 [0; 0.2]

0.25

Obstructive hypopnea index

(/h TST)

14.6 [6.4; 25.5]

13.6 [6.4; 24.7]

17.8 [8; 26.8]

0.48

Flow limitations index (/h TST)

2.2 [0.6; 5.2]

1.9 [0.2; 4.4]

2.5 [0.6; 6]

0.41

ODI (/h)

23.4 [8.7; 39]

23.7 [8.8; 39]

23.4 [8.7; 35]

0.72

Cumulative time spent below

90% of SaO₂ (min)

0 [0; 16]

0 [0; 10]

0 [0; 22]

0.93

AHI

Less than 5: No SAS

10 (10.1)

6 (9.1)

4 (12.1)

0 (0)

0.75

]5,15]: Mild SAS

15 (15.2)

9 (13.6)

6 (18.2)

]15,30]: Moderate SAS

37 (37.4)

27 (40.9)

10 (30.3)

More than 30: Severe SAS

37 (37.4)

24 (36.4)

1. (39.4)