Cardiovascular Risk Assessment in a Cohort of Newly Diagnosed Patients with Obstructive Sleep Apnea Syndrome

Table 2

Comparison of sleep characteristics between controls and obstructive sleep apnea syndrome (OSAS) patients.

	Controls	Mild OSAS	Moderate OSAS	Severe OSAS	Controls versus mild OSAS	Controls versus moderate OSAS	Controls versus severe OSAS	Mild versus moderate OSAS	Mild versus severe OSAS	Moderate versus severe OSAS
TST (min)	294.7 ± 44.6	307.4 ± 43.8	302.9 ± 51.6	282.6 ± 73.6	0.224	0.505	0.097	0.699	0.009	0.047
N1 (%)	13.5 (10.8–20.6)	14.1 (7.9–25.2)	22.1 (15.2–32.2)	23.4 (13.2–40.6)	0.467	0.234	0.528	0.910	0.721	0.549
N2 (%)	55.1 ± 14.2	52.3 ± 17.5	52.1 ± 8.4	53.2 ± 12.2	0.471	0.323	0.466	0.929	0.787	0.577
N3 (%)	9.1 (2–17.1)	6.1 (0–12)	9.8 (3–16.9)	7.2 (3.2–17.8)	0.065	0.771	0.602	0.047	0.005	0.863
REM (%)	11 (7.3–17.9)	10 (6–23.5)	13 (9.3–17.2)	9.1 (4.7–14.7)	0.494	0.951	0.386	0.691	0.307	0.282
AHI (events/h)	2 (1–3.5)	10 (6–13)	21.3 (18–27)	61.4 (45–75.7)	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001
ODI (events/h)	25.3 (14–46.7)	34.8 (10.8–50.7)	23.8 (12–60.2)	34.1 (12.7–68.7)	0.399	0.323	0.546	0.813	0.451	0.508
Aver. SpO2 (%)	92 ± 3.7	91.5 ± 4.1	92.2 ± 2.9	92.3 ± 2.7	0.547	0.863	0.713	0.444	0.200	0.862
Min. SpO2 (%)	76.7 ± 11	74.2 ± 15	80 ± 11	79.9 ± 10.2	0.419	0.242	0.123	0.091	0.039	0.976
Arousal index	18.1 (13.9–22.5)	22 (11.7–32.3)	27.9 (21.2–45.2)	23.1 (11.9–30.8)	0.166	0.310	0.388	0.484	0.013	0.055
Sleep efficiency (%)	78.5 ± 10.1	80 ± 9.4	80 ± 10.9	72.8 ± 15.8	0.514	0.572	0.019	0.998	0.002	0.009
ESS score	7.7 ± 5.6	8.9 ± 4.7	8.5 ± 5.2	10.8 ± 5.3	0.218	0.490	0.001	0.757	0.018	0.034

AHI: apnea-hypopnea index; Aver. SpO₂: average oxyhaemoglobin saturation; ESS: Epworth sleepiness scale; Min. SpO₂: minimum oxyhaemoglobin saturation; N1: sleep stage 1; N2: sleep stage 2; N3: sleep stage 3; ODI: oxygen desaturation index; REM: rapid eye movement; TST: total sleep time.