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; SpO2 = 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.