Table 1. Baseline characteristics of the patients
| Total (n=109) | Obese (n=40) | Non-obese (n=69) | p-value |
| Age (month) | 107.9±41.6 | 119.1±47.9 | 101.3±36.2 | 0.23 |
| Gender, female | 35 (32.1) | 10 (25.0) | 25 (36.2) | 0.21 |
| BMI | 20.9±5.9 | 26.2±6.0 | 17.8±2.8 | <0.001† |
| 25(OH)D (ng/mL) | 19.5±7.1 | 17.9±6.5 | 20.4±7.3 | 0.08 |
| 25(OH)D deficiency | 65 (59.6) | 28 (70.0) | 37 (53.6) | 0.07 |
| PSG parameter |
| TST (minute) | 509.1±467.7 | 461.7±40.1 | 536.6±586.9 | 0.42 |
| AHI | 5.4±15.8 | 11.5±23.7 | 1.9±6.2 | 0.02* |
| Obstructive | 0.2±0.7 | 0.5±1.0 | 0.1±0.4 | 0.04* |
| Central | 0.2±0.2 | 0.2±0.3 | 0.2±0.2 | 0.83 |
| Mixed | 0.01±0.06 | 0.02±0.09 | 0 | 0.09 |
| Hypopnea | 4.9±14.9 | 10.7±22.4 | 1.6±5.9 | 0.02* |
| AHI_supine | 6.5±17.1 | 13.5±25.3 | 2.3±7.1 | 0.01* |
| AHI_non-supine | 3.5±12.4 | 6.7±18.7 | 1.7±5.9 | 0.11 |
| ODI | 9.1±17.2 | 17.1±24.9 | 4.3±7.0 | <0.01* |
| SpO2 mean (%) | 96.6±1.3 | 96.2±1.7 | 96.9±0.9 | 0.02* |
| SpO2 nadir (%) | 86.7±6.9 | 83.6±7.7 | 88.6±5.6 | <0.01* |
| Season |
| Summer | 28 (25.7) | 14 (35) | 14 (20.3) | 0.09 |
| Spring, fall, and winter | 81 (74.3) | 26 (65) | 55 (93.2) | |
Data are represented as the mean±standard deviation or n (%). p-values are from the Fisher’s exact test (categorical variables variables) or Mann-Whitney U test (quantitative variables).
p<0.05,
p<0.001.
BMI: body mass index, 25(OH)D: 25-hydroxyvitamin D, PSG: polysomnography, TST: total sleep time, AHI: apnea hypopnea index, ODI: oxygen desaturation index, SpO2 mean: average oxygen saturation, SpO2 nadir: minimal oxygen saturation.