. 2022 Sep 16;22:349. doi: 10.1186/s12890-022-02146-0

Table 5.

Polysomnographic indices according to hyoid bone position

Variable	Longer MPH distance group (n = 67)	Shorter MPH distance group (n = 66)	p-value
Total AHI^a	33.9 (27.1)	21.8 (16.2)	0.002**
Supine AHI^a	42.3 (29.7)	28.1 (20.7)	0.002**
Non-supine AHI^a	16.4 (25.6)	6.3 (11.3)	0.004**
REM AHI^a	36.6 (25.6)	33.4 (20.8)	0.428
NREM AHI^a	33.0 (28.5)	19.4 (17.2)	0.001**
Severe OSA group^b	43.3%	27.3%	0.040*
Mean SpO₂ (%)^a	94.7 (2.1)	95.6 (1.6)	0.013*
Lowest SpO₂ (%)^a	79.1 (10.1)	82.0 (9.0)	0.084
REM SpO₂ (%)^a	94.1 (3.3)	93.9 (11.9)	0.890
NREM SpO₂ (%)^a	94.7 (2.2)	95.6 (1.6)	0.009**
Time below 90% SpO₂ (%)^a	7.4 (11.2)	2.7 (4.6)	0.003**
Total sleep time (min)^a	315.3 (66.8)	326.3 (60.9)	0.326
Sleep efficiency (%)^a	79.0 (13.0)	82.2 (10.3)	0.121
Sleep latency (min)^a	17.1 (17.8)	15.1 (15.0)	0.494
REM latency (min)^a	113.1 (54.5)	125.1 (62.7)	0.240
Sleep stage I (%)^a	31.7 (17.0)	24.4 (12.9)	0.006**
Sleep stage II (%)^a	45.4 (14.7)	50.9 (13.4)	0.026*
Sleep stage III + IV (%)^a	1.8 (3.8)	3.2 (6.5)	0.121
REM sleep (%)^a	16.9 (7.0)	16.8 (6.9)	0.931
Time of supine position (%)^a	68.7 (26.9)	76.2 (21.9)	0.078
REM arousal index^a	18.5 (15.7)	15.2 (13.1)	0.211
NREM arousal index^a	18.7 (19.0)	11.4 (13.3)	0.016*
Respiratory arousal index^a	22.6 (20.7)	12.7 (12.3)	0.001**
Total arousal index^a	34.8 (17.9)	24.8 (12.3)	0.001**

MPH distance The distance between hyoid bone and mandibular plane; AHI Apnea-hypopnea index; REM Rapid eye movement sleep; NREM Non-rapid eye movement sleep; OSA Obstructive sleep apnea; SpO₂ Oxygen saturation; TST Total sleep time

^aResults were obtained from independent t-test: mean (SD)

^bResults were obtained from chi-square test

*Significant difference: p < 0.05

**Significant difference: p < 0.01