Table 1.

Patient Characteristics, Sleep Parameters, and Functional Gain after AIH Therapy (Cohen’s d)

	No Apnea (n = 10)	Mild to Moderate Apnea (n = 10)	P Value*	Mild Apnea 5 ≤ AHI < 15 (n = 7)	Moderate Apnea 15 < AHI < 30 (n = 3)
AHI, no./h†	1.5 (0–4)	9.0 (6–29)	<0.001	6.5 (6–10)	23 (17–29)
Cohen’s d	0.2 ± 4.0	4.2 ± 3.8	0.043	2.4 ± 2.3	7.8 ± 4.6
Age, yr	46 ± 14	45 ± 8	0.90	42 ± 15	53 ± 14
Level of injury†	C5 (C2–T4)	C5 (C4–T8)	0.26	C5 (C5–T8)	C5 (C4–T3)
Time since injury, yr†	7 (3–38)	7 (3–25)	0.64	7.5 (6–18)	11 (7–24)
BMI, kg/m2†	20 (19–30)	24 (20–33)	0.23	24 (20–25)	28 (24–33)
Sleep parameters
Evaluation duration, h/night	6 ± 2	7 ± 2	0.42	6 ± 2	8 ± 1
Apnea index, no./h†	0 (0–2.5)	2.5 (0.5–27)	0.001	1.5 (0.5–4.3)	14 (0.5–27)
Hypopnea index, no./h	1.1 ± 0.9	5.6 ± 2.1	<0.001	5.1 ± 1.0	5.6 ± 3.7
Oxygen desaturation index, no./h†	1 (0–6)	10 (4–34)	<0.001	8.5 (4–13)	23 (4–34)
Average SpO2, %	93 ± 4	91 ± 4	0.048	93 ± 2	89 ± 7
Average SpO2 nadir, %	91 ± 5	84 ± 6	0.005	87 ± 2	76 ± 3
Time with SpO2 ≤ 90%, min†	2 (0–36)	67 (1–137)	0.002	48 (1–110)	85 (1–137)
Average pulse frequency, beats/min	65 ± 9	65 ± 10	0.95	65 ± 12	65 ± 6
Highest pulse frequency, beats/min	130 ± 41	114 ± 32	0.77	102 ± 29	140 ± 42
Snoring events, no./h	578 ± 673	653 ± 760	0.47	353 ± 411	1,353 ± 1,023

Definition of abbreviations: AHI = apnea–hypopnea index; AIH = acute intermittent hypoxia; BMI = body mass index; Sp_O2 = pulse oxygen saturation.

Data are mean ± SD except where otherwise noted.

^*Comparison between “no apnea” and “apnea” (mild to moderate apnea) (t test or Mann-Whitney rank test comparisons).

^†Median (range) for nonparametric variables.