Table 1.
Characteristics of study subjects.
| n | OSA |
Control |
p value |
|---|---|---|---|
| 60 | 15 | ||
| Age, yr | 47 (39.3–56.8) | 44 (35.0–49.0) | 0.228 |
| Male, % | 88.3 | 80.0 | 0.408† |
| BMI, kg/m2 | 28.0 (25.5–31.1) | 24.5 (22.77–25.83) | <0.001 |
| ESS score | 8 (5–12) | 6 (4–8) | 0.052 |
| Dry mouth, % | 38.3% | 13.3% | 0.066‡ |
| Polysomnography | |||
| Time in bed (min) | 363 (362–367) | 362 (359–364) | 0.065 |
| Total sleep time (min) | 321.8 (305–338.3) | 312 (271–338) | 0.223 |
| Sleep efficiency (%) | 89.2 (83.7–92.7) | 85.9 (75.8–92.9) | 0.305 |
| AHI (/hr) | 41.7 (18.0–65.1) | 1.8 (1.4–3.4) | – |
| SpO2, nadir (%) | 76.5 (69–81.8) | 90 (88–94) | <0.001 |
| ODI (/hr) | 40.2 (15.1–57.0) | 1.4 (0.5–2.7) | <0.001 |
| Time spent for | |||
| SpO2<95% (min) | 138.3 (90.1–226.2) | 4.5 (0.3–61.9) | <0.001 |
| SpO2<90% (min) | 24 (4.9–66.3) | 0 (0–0.2) | <0.001 |
| SpO2<85% (min) | 4.4 (0.5–16.6) | 0 (0–0) | <0.001 |
| Blood tests | |||
| White blood cell (103/μL) | |||
| Night | 7.70 (6.40–9.53) | 5.70 (5.40–8.70) | 0.033 |
| Morning | 6.95 (5.80–9.25) | 5.40 (4.70–6.80) | 0.014 |
| Difference | −0.5 (−1.08–−0.1) | −0.7 (−1.3–−0.3) | 0.292 |
| Hemoglobin (g/dL) | |||
| Night | 14.7 (13.70–15.28) | 14.5 (13.40–15.40) | 0.827 |
| Morning | 15.0 (14.10–15.88) | 14.8 (13.70–15.40) | 0.260 |
| Difference | 0.50 (0.20–0.78) | 0.30 (−0.20–0.40) | 0.002 |
| Hematocrit (%) | |||
| Night | 43.05 (40.75–45.23) | 43.20 (39.20–45.80) | 0.889 |
| Morning | 44.55 (42.15–47.03) | 44.20 (39.9–45.50) | 0.286 |
| Difference | 1.35 (0.50–2.30) | 1.0 (−0.2–1.20) | 0.013 |
| Platelet (103/μL) | |||
| Night | 235 (191.3–276.5) | 245 (212–305) | 0.525 |
| Morning | 235.5 (193.5–271.0) | 225 (197–262) | 0.848 |
| Difference | −4.5 (−14.0–1.75) | −14 (−25–−9) | 0.002 |
| Estimated change in plasma volume (%) | −5.5 (−2.3∼ −8.7) | −3.7 (−4.7–1.7) | <0.005 |
Data are given as median (interquartile range). p values for comparisons between two groups are determined by Mann–Whitney U test unless noted otherwise. †Fisher's exact test. ‡Pearson's χ2 test. Abbreviations: OSA: obstructive sleep apnea; AHI: apnea-hypopnea index; BMI: body mass index; ESS: Epworth Sleepiness Scale; SpO2: arterial oxyhemoglobin saturation by pulse oximetry; ODI: oxygen desaturation index.