Table 1.
Characteristics of study patients in total and by incident major adverse cardiovascular events (MACEs) (n=1860)
| Variables | Total (n=1860) |
Incident case (n=278) |
Event free (n=1582) |
P for difference |
| Demographics | ||||
| Male, n (%) | 1236 (66.5%) | 200 (71.9%) | 1036 (65.5%) | 0.042 |
| Age, year | 52.4 (12.2) | 59.0 (12.2) | 51.2 (11.9) | <0.001 |
| Symptom and measures | ||||
| BMI, kg/m2 | 27.7 (5.3) | 28.0 (5.0) | 27.7 (5.4) | 0.367 |
| Neck circumference, cm | 38.4 (4.0) | 39.3 (4.7) | 38.3 (3.9) | 0.001 |
| Waist circumference, cm | 93.1 (12.4) | 95.2 (11.2) | 92.7 (12.6) | <0.001 |
| Hip circumference, cm | 99.3 (9.8) | 98.5 (9.1) | 99.4 (9.9) | 0.130 |
| Epworth Sleepiness Scale | 8.7 (5.4) | 8.4 (5.5) | 8.7 (5.3) | 0.307 |
| Polysomnogram | ||||
| TST, min | 422.0 (371.5–458.5) | 407.5 (356.0–455.0) | 423.0 (373.6–459.0) | 0.039 |
| AHI, /hour | 21.7 (8.0–46.9) | 28.3 (10.3–52.9) | 20.5 (7.5–45.8) | 0.003 |
| REM-AHI, /hour | 30.9 (11.2–54.3) | 36.9 (15.0–57.2) | 30.0 (10.8–54.0) | 0.052 |
| 3% ODI, /hour | 16.4 (4.8–41.0) | 22.9 (8.5–49.3) | 15.6 (4.4–39.0) | <0.001 |
| Mean SpO2, % | 95.0 (93.7–96.0) | 94.7 (93.1–96.0) | 95.0 (93.8–96.1) | <0.001 |
| Min SpO2, % | 81.0 (71.0–87.0) | 79.0 (68.0–86.0) | 81.0 (72.0–87.0) | 0.005 |
| TST90, min | 6.8 (0.7–36.4) | 17.1 (1.9–56.9) | 5.8 (0.6–30.7) | <0.001 |
| Arousal Index, /hour | 19.0 (11.8–31.0) | 21.8 (14.0–36.2) | 18.4 (11.3–30.2) | <0.001 |
| Mean AHD, s | 22.5 (18.9–26.8) | 22.2 (18.8–26.4) | 22.5 (18.9–26.8) | 0.553 |
| Nocturnal MHR, /min | 63.8 (58.5–70.1) | 65.7 (58.3–71.9) | 63.8 (58.5–69.8) | 0.048 |
| Wake MHR, /min | 69.2 (63.0–75.7) | 71.0 (62.9–79.1) | 68.9 (63.0–75.3) | 0.016 |
| History | ||||
| Prior hypertension, n (%) | 1187 (63.8%) | 229 (63.8%) | 958 (60.6%) | <0.001 |
| Prior diabetes, n (%) | 586 (31.5%) | 138 (31.5%) | 447 (28.3%) | <0.001 |
| Fasting glucose, mmol/L | 5.4 (4.9–6.5) | 5.9 (5.0–7.7) | 5.4 (4.9–6.4) | <0.001 |
| Prior hyperlipidaemia, n (%) | 614 (33.0%) | 116 (33.0%) | 498 (31.5%) | 0.001 |
| Total cholesterol, mmol/L | 4.9 (4.2–5.6) | 4.8 (4.1–5.5) | 4.9 (4.3–5.6) | 0.262 |
| Triglycerides, mmol/L | 1.6 (1.1–2.2) | 1.6 (1.2–2.3) | 1.6 (1.1–2.2) | 0.110 |
| Prior CVDs, n (%) | 232 (12.5%) | 77 (27.7%) | 155 (9.8%) | <0.001 |
| Statin use, n (%) | 442 (23.8%) | 92 (33.1%) | 350 (22.1%) | <0.001 |
| Beta blocker use, n (%) | 442 (23.8%) | 118 (42.4%) | 324 (20.5%) | <0.001 |
| Family history of CVD, n (%) | 466 (25.1%) | 75 (25.1%) | 391 (24.7%) | 0.467 |
| Cigarette smoking, n (%) | <0.001 | |||
| No | 1262 (67.8%) | 161 (57.9%) | 1101 (69.6%) | |
| Former | 263 (14.1%) | 47 (16.9%) | 216 (13.7%) | |
| Current | 332 (17.8%) | 69 (24.8%) | 263 (16.6%) | |
| Alcohol use, n (%) | 0.014 | |||
| No | 1411 (75.8%) | 198 (71.2%) | 1213 (76.7%) | |
| Former | 314 (16.9%) | 49 (17.6%) | 265 (16.8%) | |
| Current | 127 (6.8%) | 30 (10.8%) | 97 (6.1%) | |
| Physical activity, n (%) | 0.028 | |||
| Low | 1199 (64.5%) | 198 (71.2%) | 1001 (63.3%) | |
| Medium | 542 (29.1%) | 63 (22.7%) | 479 (30.3%) | |
| High | 101 (5.4%) | 14 (5.0%) | 87 (5.5%) | |
| Education level, n (%) | <0.001 | |||
| Primary or below | 501 (26.9%) | 109 (39.2 %) | 392 (24.8%) | |
| Secondary | 827 (44.5%) | 111 (39.9%) | 716 (45.3%) | |
| Tertiary | 529 (28.4%) | 57 (20.5%) | 472 (29.8%) | |
| Body weight change*, kg | 1.4 (6.4) | 0.8 (6.2) | 1.5 (6.5) | 0.127 |
| Regular CPAP use, n (%) | 293 (15.8%) | 42 (15.1%) | 251 (15.9%) | 0.818 |
| Follow-up time, months | 99.5 (70.6–122.9) | 53.9 (26.0–75.7) | 104.2 (80.3–125.6) | <0.001 |
Data are given as mean (SD), median (IQR) or n (%).
Numbers may not add to total because of missing values.
*Body weight change was defined as body weight at endpoint or censoring minus baseline body weight.
AHD, apnoea–hypopnoea duration; AHI, apnoea–hypopnoea index; BMI, body mass index; CVDs, cardiovascular diseases; MACEs, major adverse cardiovascular events; MHR, mean heart rate; ODI, oxygen desaturation index; OSA, obstructive sleep apnoea; REM-AHI, apnoea–hypopnoea index during rapid eye movement sleep; SpO2, peripheral capillary oxygen saturation; TST90, sleep time with oxygen saturation below 90; TST, total sleep time.