Table 1.

Characteristics of patients with obstructive sleep apnea (OSA) and controls.

Variables	Controls	Mild	Moderate	Severe	p value	p value	p value	p value	p value	p value	p value
					Across all	Controls versus mild	Controls versus moderate	Controls versus severe	Mild versus moderate	Mild versus severe	Moderate versus severe
Age (years)	38.8 ± 14.1	40.0 ± 11.8	43.4 ± 11.5	44.2 ± 11.1	<0.001	0.77	0.001	<0.001	0.013	<0.001	0.86
Gender (males, %)	53.7	77.1	75.5	84.9	<0.001	<0.001	<0.001	<0.001	0.69	0.013	0.004
BMI (kg/m2)	26.6 (6)	29.1 (6)	30.8 (7)	34.3 (11)	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001
Normal (18.5–24.9), n (%)	33.7	10.0	6.5	2.9	<0.001	<0.001	<0.001	<0.001	0.16	<0.001	0.03
Overweight (25–29.9), n (%)	42.1	55.5	35.3	19.6	<0.001	0.05	0.16	<0.001	<0.001	<0.001	<0.001
Obese (≥30), n (%)	24.2	38.1	58.2	77.3	<0.001	0.002	<0.001	<0.001	<0.001	<0.001	<0.001
Current smokers (%)	34.2	34.5	39.5	43.3	0.074	0.95	0.27	0.036	0.26	0.028	0.35
Former smokers (%)	18.4	20.2	21.5	29.2	0.008	0.65	0.44	0.005	0.73	0.012	0.033
Never smokers (%)	47.4	45.4	39.1	27.4	<0.001	0.68	0.09	<0.001	0.17	<0.001	0.003
Pack years	10 (28)	12 (25)	14 (30)	18 (35)	<0.001	0.75	0.42	<0.001	0.51	<0.001	0.002
ESS	7 (9)	8 (8)	9 (9)	12 (9)	<0.001	0.93	0.003	<0.001	0.002	<0.001	0.002
AHI (/h)	2 (2)	10 (6)	21 (6)	57 (34)	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001
ODI (/h)	2 (2)	9 (5)	20 (8)	59 (34)	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001
AI (/h)	24 (14)	31 (14)	34 (18)	46 (25)	<0.001	<0.001	<0.001	<0.001	0.04	<0.001	<0.001
Mean SaO2	96 (2)	95 (1)	94 (2)	92 (39)	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001
Min SaO2	92 (3)	88.5 (4)	85 (5)	79 (66)	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001
TST90 (min)	0 (0)	1 (3)	9 (11)	69 (101)	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001

BMI: body mass index; ESS: Epworth sleepiness scale; AHI: apnea-hypopnea index; AI: arousal index; ODI: oxygen desaturation index; SaO₂: oxygen saturation; TST90: sleep time spent with SaO2 less than 90%.