Table 1.
Demographic and sleep characteristics across OSA severity categories
| Characteristics | Total OSA (n = 4507) |
Mild OSA (n = 878) |
Moderate OSA (n = 891) |
Severe OSA (n = 2738) |
P |
|---|---|---|---|---|---|
| Demographic and clinical characteristics | |||||
| Men, n (%) | 3819 (84.73) | 663 (75.51) | 715 (80.25) | 2441 (89.15) | <.0001* |
| Age (years) | 43.52 ± 11.67 | 42.19 ± 12.14 | 44.71 ± 12.41 | 43.56 ± 11.22 | <.0001* |
| Neck circumference (cm) | 39.91 ± 3.48 | 38.19 ± 3.28 | 39.02 ± 3.28 | 40.74 ± 3.34 | <.0001* |
| Waist circumference (cm) | 97.29 ± 10.40 | 92.10 ± 10.25 | 94.72 ± 9.48 | 99.81 ± 9.88 | <.0001* |
| Hip circumference (cm) | 102.10 ± 7.81 | 99.44 ± 7.52 | 100.65 ± 7.51 | 103.50 ± 7.69 | <.0001* |
| Waist hip ratio | 0.95 ± 0.18 | 0.92 ± 0.07 | 0.95 ± 0.31 | 0.97 ± 0.18 | <.0001* |
| BMI (kg/m2) | 27.25 ± 3.85 | 25.53 ± 3.35 | 26.37 ± 3.60 | 28.08 ± 3.84 | <.0001* |
| Hypertension, n (%) | 1676 (37.19) | 212 (24.15) | 310 (34.79) | 1154 (42.15) | <.0001* |
| SBP (mmHg) | 127.7 ± 15.64 | 124.53 ± 14.85 | 126.03 ± 16.31 | 129.28 ± 15.46 | <.0001* |
| DBP (mmHg) | 82.18 ± 11.73 | 79.19 ± 11.23 | 80.21 ± 11.39 | 83.76 ± 11.72 | <.0001* |
| Diabetes mellitus, n (%) | 409 (9.07) | 54 (6.15) | 68 (7.63) | 287 (10.48) | 0.0001* |
| Hyperlipidemia, n (%) | 1396 (25.63) | 165 (18.79) | 228 (25.59) | 885 (32.32) | <.0001* |
| Smoking, n (%) | 1956 (43.40) | 291 (33.14) | 344 (38.61) | 1321 (48.25) | <.0001* |
| Alcohol consumption, n (%) | 533 (11.83) | 61 (6.95) | 78 (8.75) | 394 (14.39) | <.0001* |
| Fasting glucose (mmol/l) | 5.60 ± 1.29 | 5.38 ± 1.28 | 5.50 ± 1.25 | 5.70 ± 1.30 | <.0001* |
| Fasting insulin (μU/ml) | 11.70 (7.86,17.23) | 9.38 (6.29,14.21) | 10.48 (7.28,15.26) | 12.91 (8.88,18.83) | <.0001* |
| HOMA-IR | 2.81 (1.81,4.36) | 2.12 (1.41,3.41) | 2.46 (1.66,3.72) | 3.14 (2.08,4.84) | <.0001* |
| Cholesterol (mmol/l) | 4.87 ± 1.00 | 4.74 ± 0.99 | 4.78 ± 0.89 | 4.93 ± 1.03 | <.0001* |
| Triglyceride (mmol/l) | 2.16 ± 1.88 | 1.80 ± 1.63 | 1.97 ± 1.43 | 2.34 ± 2.05 | <.0001* |
| High density lipoprotein (mmol/l) | 1.05 ± 0.25 | 1.10 ± 0.27 | 1.07 ± 0.25 | 1.03 ± 0.24 | <.0001* |
| Low density lipoprotein (mmol/l) | 3.05 ± 0.83 | 2.99 ± 0.84 | 3.01 ± 0.80 | 3.09 ± 0.83 | 0.0018* |
| ApolipoproteinA-1(g/l) | 1.07 ± 0.19 | 1.08 ± 0.20 | 1.08 ± 0.21 | 1.06 ± 0.18 | 0.0254* |
| Apolipoprotein-B(g/l) | 0.88 ± 0.20 | 0.84 ± 0.19 | 0.86 ± 0.19 | 0.90 ± 0.21 | <.0001* |
| Apolipoprotein-E (mg/dl) | 4.81 ± 2.28 | 4.37 ± 1.64 | 4.69 ± 2.90 | 4.99 ± 2.21 | <.0001* |
| Lipoprotein-α (mg/dl) | 12.22 ± 14.22 | 13.90 ± 16.49 | 12.80 ± 14.89 | 11.50 ± 13.14 | <.0001* |
| ESS | 9.12 ± 5.87 | 7.03 ± 5.15 | 7.36 ± 5.21 | 10.36 ± 5.95 | <.0001* |
| ESS > 10, n (%) | 1773 (39.34) | 217 (24.72) | 239 (26.82) | 1317 (48.10) | <.0001* |
| Polysomnography | |||||
| Total sleep duration, min | 398.1 ± 76.20 | 385.35 ± 78.45 | 389.58 ± 77.67 | 404.96 ± 74.18 | <.0001* |
| Total time in bed, min | 491.3 ± 94.89 | 491.36 ± 91.61 | 491.62 ± 93.78 | 491.24 ± 96.31 | 0.9944 |
| Sleep efficiency (%) | 0.82 ± 0.15 | 0.79 ± 0.15 | 0.80 ± 0.16 | 0.84 ± 0.14 | <.0001* |
| S1(% TST) | 18.38 ± 14.23 | 16.74 ± 12.84 | 17.64 ± 13.61 | 19.14 ± 14.79 | <.0001* |
| S2(% TST) | 49.08 ± 19.80 | 47.66 ± 18.93 | 47.97 ± 19.58 | 49.90 ± 20.11 | 0.0024* |
| S3(% TST) | 12.81 ± 10.88 | 15.40 ± 10.93 | 14.04 ± 10.39 | 11.57 ± 10.83 | <.0001* |
| REM(% TST) | 10.43 ± 6.57 | 10.90 ± 6.89 | 10.57 ± 6.62 | 10.23 ± 6.44 | 0.0246* |
| AHI (events/h) | 41.80 ± 25.31 | 9.55 ± 2.94 | 22.03 ± 4.26 | 58.58 ± 17.41 | <.0001* |
| LSpO2,% | 74.95 ± 13.46 | 85.94 ± 9.13 | 81.36 ± 8.96 | 69.34 ± 12.72 | <.0001* |
| ODI | 42.11 ± 26.83 | 10.72 ± 9.04 | 23.12 ± 9.59 | 58.35 ± 20.77 | <.0001* |
| Mean SaO2 | 93.33 ± 3.56 | 95.67 ± 1.51 | 95.01 ± 1.68 | 92.03 ± 3.86 | <.0001* |
| MAI | 31.52 ± 22.24 | 20.47 ± 18.53 | 23.44 ± 16.68 | 37.70 ± 22.70 | <.0001* |
Acronyms: OSA Obstructive sleep apnea, BMI Body mass index, HOMA-IR Homeostasis model assessment for insulin resistance, SBP Systolic blood pressure, DBP Diastolic blood pressure, ESS Epworth Sleepiness Scale, AHI Apnea–hypopnea index, TST Total sleep time, REM Rapid eye movement, LSpO2 Lowest oxygen saturation, ODI Oxygen desaturation index, SaO2 Oxygen saturation
The data are presented as means and standard deviation (SD) and categorical data as the number (percentage)
Differences in the baseline characteristics among the four groups were examined using the polynomial linear trend test for continuous variables and the linear-by-linear association test for dichotomous variables
* p indicates a significant difference