Table 1. Baseline clinical, laboratory, and polysomnographic data of the study population.
| Characteristics | Control (n=169) | Mild OSA (n=145) | Moderate OSA (n=94) | Severe OSA (n=249) | P value |
|---|---|---|---|---|---|
| Clinical parameters | |||||
| Age (years) | 30.51±11.83 | 36.21±15.50* | 38.65±16.25* | 43.80±13.77*†§ | <0.001 |
| Male gender, n (%) | 67 (39.64) | 80 (55.17)* | 57 (60.64)* | 211 (84.74)*†§ | <0.001 |
| BMI (kg/m2) | 33.19±5.60 | 32.14±6.61 | 32.82±7.01 | 31.72±6.91* | 0.125 |
| Neck circumference (cm) | 40.16±3.17 | 40.73±3.74 | 41.17±3.90* | 42.39±4.25*† | <0.001 |
| Cigarette smoking, n (%) | 20 (11.83) | 20 (13.79) | 16 (17.02) | 61 (24.50)*† | 0.004 |
| Hypertension, n (%) | 44 (26.04) | 61 (42.07)* | 36 (38.30)* | 149 (59.84)*†§ | <0.001 |
| Diabetes mellitus, n (%) | 38 (22.49) | 32 (22.07) | 27 (28.72) | 94 (37.75)*† | 0.001 |
| Dyslipidemia, n (%) | 65 (38.46) | 72 (49.66)* | 56 (59.57)* | 166 (66.67)*† | <0.001 |
| CVD, n (%) | 11 (6.51) | 8 (5.52) | 11 (11.70) | 98 (39.36)*†§ | <0.001 |
| Laboratory parameters | |||||
| WBC count (103/μL) | 7.46±1.75 | 7.46±1.72 | 7.45±1.98 | 7.49±2.11 | 0.997 |
| Neutrophil count (103/μL) | 4.28±1.61 | 4.25±1.27 | 4.33±1.75 | 4.32±1.81 | 0.967 |
| Monocyte count (103/μL) | 0.51±0.15 | 0.52±0.17 | 0.53±0.16 | 0.53±0.18 | 0.733 |
| Triglyceride (mg/dL) | 125.81 (92.14–171.00) | 134.67 (103.22–209.10)* | 160.37 (112.08–216.63)* | 174.99 (129.36–253.17)*† | <0.001 |
| Total cholesterol (mg/dL) | 177.63±68.13 | 176.88±48.15 | 184.73±35.66 | 184.39±36.72 | 0.315 |
| HDL cholesterol (mg/dL) | 42.38±12.39 | 41.64±9.24 | 41.44±10.05 | 39.41±11.3*† | 0.038 |
| LDL cholesterol (mg/dL) | 110.81±41.56 | 113.32±68.93 | 113.91±31.85 | 114.09±31.14 | 0.897 |
| MHR | 12.86±4.74 | 13.06±5.33 | 13.59±5.86 | 14.53±6.37*† | 0.014 |
| Polysomnographic parameters | |||||
| AHI (events/h) | 1.94±1.40 | 9.46±2.84* | 22.16±4.35*† | 57.87±17.95*†§ | <0.001 |
| Mean SpO2 (%) | 96.22±1.46 | 95.56±2.14* | 94.79±2.19*† | 91.78±4.69*†§ | <0.001 |
| LSpO2 (%) | 90.0 (85.5–92.0) | 85.0 (79.0–89.0)* | 80.0 (72.0–86.0)*† | 67.0 (55.5–77.0)*†§ | <0.001 |
| TS90 (%) | 0.00 (0.00–0.20) | 0.30 (0.00–1.60)* | 1.37 (0.20–6.73)*† | 18.30 (5.80–39.39)*†§ | <0.001 |
Data are means ± standard deviation, numbers of subjects (%), or medians (range). OSA, obstructive sleep apnea; BMI, body mass index; CVD, cardiovascular disease; WBC, white blood cell; HDL, high density-lipoprotein; LDL, low density-lipoprotein; MHR, monocyte to high-density lipoprotein cholesterol ratio; AHI, apnea-hypopnea index; Mean SpO2, mean oxygen saturation; LSpO2, lowest pulse oxygen saturation; TS90, the percentage of sleep duration with SpO2 <90%. *, severe OSA vs. Control, P<0.05; †, severe OSA vs. mild OSA, P<0.05; §, severe OSA vs. moderate OSA, P<0.05.