Table 1

Characteristics of study patients in total and by incident major adverse cardiovascular events (MACEs) (n=1860)

VariablesTotal
(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, year52.4 (12.2)59.0 (12.2)51.2 (11.9)<0.001
Symptom and measures
 BMI, kg/m227.7 (5.3)28.0 (5.0)27.7 (5.4)0.367
 Neck circumference, cm38.4 (4.0)39.3 (4.7)38.3 (3.9)0.001
 Waist circumference, cm93.1 (12.4)95.2 (11.2)92.7 (12.6)<0.001
 Hip circumference, cm99.3 (9.8)98.5 (9.1)99.4 (9.9)0.130
 Epworth Sleepiness Scale8.7 (5.4)8.4 (5.5)8.7 (5.3)0.307
Polysomnogram
 TST, min422.0 (371.5–458.5)407.5 (356.0–455.0)423.0 (373.6–459.0)0.039
 AHI, /hour21.7 (8.0–46.9)28.3 (10.3–52.9)20.5 (7.5–45.8)0.003
 REM-AHI, /hour30.9 (11.2–54.3)36.9 (15.0–57.2)30.0 (10.8–54.0)0.052
 3% ODI, /hour16.4 (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, min6.8 (0.7–36.4)17.1 (1.9–56.9)5.8 (0.6–30.7)<0.001
 Arousal Index, /hour19.0 (11.8–31.0)21.8 (14.0–36.2)18.4 (11.3–30.2)<0.001
 Mean AHD, s22.5 (18.9–26.8)22.2 (18.8–26.4)22.5 (18.9–26.8)0.553
 Nocturnal MHR, /min63.8 (58.5–70.1)65.7 (58.3–71.9)63.8 (58.5–69.8)0.048
 Wake MHR, /min69.2 (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/L5.4 (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/L4.9 (4.2–5.6)4.8 (4.1–5.5)4.9 (4.3–5.6)0.262
 Triglycerides, mmol/L1.6 (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
 No1262 (67.8%)161 (57.9%)1101 (69.6%)
 Former263 (14.1%)47 (16.9%)216 (13.7%)
 Current332 (17.8%)69 (24.8%)263 (16.6%)
Alcohol use, n (%)0.014
 No1411 (75.8%)198 (71.2%)1213 (76.7%)
 Former314 (16.9%)49 (17.6%)265 (16.8%)
 Current127 (6.8%)30 (10.8%)97 (6.1%)
Physical activity, n (%)0.028
 Low1199 (64.5%)198 (71.2%)1001 (63.3%)
 Medium542 (29.1%)63 (22.7%)479 (30.3%)
 High101 (5.4%)14 (5.0%)87 (5.5%)
Education level, n (%)<0.001
 Primary or below501 (26.9%)109 (39.2 %)392 (24.8%)
 Secondary827 (44.5%)111 (39.9%)716 (45.3%)
 Tertiary529 (28.4%)57 (20.5%)472 (29.8%)
Body weight change*, kg1.4 (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, months99.5 (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.