Association between cardiometabolic risk factors and sleep disturbance score*
| Variable | N | All groups | Mean ± SD or no (%) | p value | ||
|---|---|---|---|---|---|---|
| Tertile 1 (sleep disturbance score 0–3) | Tertile 2 (sleep disturbance score 4–8) | Tertile 3 (sleep disturbance score ≤ 9) | ||||
| No. (%) of participants | 1171 (34.7) | 1176 (34.9) | 1025 (30.4) | |||
| Age at assessment, yr | 3372 | 14.6 ± 0.5 | 14.6 ± 0.5 | 14.6 ± 0.5 | 14.6 ± 0.5 | 0.2 |
| Male | 3372 | 1650 (48.9) | 694 (59.3) | 586 (49.8) | 370 (36.1) | < 0.001 |
| Hours of sleep | ||||||
| Weeknights | 3235 | 7.9 ± 1.1 | 8.2 ± 1.0 | 8.0 ± 1.1 | 7.6 ± 1.3 | < 0.001 |
| Weekend nights | 3176 | 9.4 ± 1.6 | 9.5 ± 1.6 | 9.4 ± 1.6 | 9.2 ± 1.8 | < 0.001 |
| Average | 3372 | 8.4 ± 1.0 | 8.6 ± 0.9 | 8.4 ± 1.0 | 8.0 ± 1.1 | < 0.001 |
| Quartile 1: ≤ 7.75 h | 966 (28.7) | 231 (19.7) | 324 (27.6) | 411 (40.1) | < 0.001 | |
| Quartile 2: > 7.75 to ≤ 8.40 h | 784 (23.3) | 275 (23.5) | 268 (22.8) | 241 (23.5) | ||
| Quartile 3: > 8.40 to ≤ 9.00 h | 897 (26.6) | 361 (30.8) | 320 (27.2) | 216 (21.1) | ||
| Quartile 4: > 9.00 h | 725 (21.5) | 304 (26.0) | 264 (22.5) | 157 (15.3) | ||
| History of premature cardiovascular disease in first-degree relative† | 3227 | 1057 (32.8) | 324 (28.7) | 367 (32.4) | 366 (37.8) | < 0.001 |
| Lipid profile | ||||||
| Total cholesterol, mmol/L | 2955 | 3.85 ± 0.74 | 3.81 ± 0.72 | 3.83 ± 0.73 | 3.92 ± 0.78 | 0.003 |
| > 5.2 mmol/L (high) | 137 (4.6) | 43 (4.2) | 45 (4.3) | 49 (5.6) | 0.03 | |
| > 4.4–5.2 mmol/L (borderline) | 494 (16.7) | 157 (15.3) | 164 (15.6) | 173 (19.6) | ||
| HDL cholesterol | 2953 | 1.23 ± 0.33 | 1.21 ± 0.33 | 1.23 ± 0.33 | 1.23 ± 0.34 | 0.3 |
| Non-HDL cholesterol | 2955 | 2.63 ± 0.72 | 2.60 ± 0.70 | 2.60 ± 0.72 | 2.70 ± 0.75 | 0.003 |
| > 3.75 mmol/L (high) | 215 (7.3) | 66 (6.4) | 74 (7.1) | 75 (8.5) | 0.003 | |
| > 3.10 to 3.75 mmol/L (borderline) | 446 (15.1) | 147 (14.3) | 137 (13.1) | 162 (18.4) | ||
| Adiposity | ||||||
| BMI z score‡ (5th, 95th percentile) | 3277 | 0.5 (−0.2, 1.4) | 0.4 (−0.3, 1.3) | 0.5 (−0.3, 1.3) | 0.7 (−0.1, 1.5) | < 0.001 |
| Overweight (> 85–95%) | 480 (14.7) | 150 (13.2) | 172 (15.0) | 158 (15.9) | 0.005 | |
| Obese (> 95%) | 612 (18.7) | 206 (18.1) | 189 (16.5) | 217 (21.8) | ||
| Waist circumference percentile | 3270 | 0.02 | ||||
| < 10th | 307 (9.4) | 119 (10.5) | 103 (9.0) | 85 (8.6) | ||
| 10th–24th | 399 (12.2) | 145 (12.8) | 147 (12.9) | 107 (10.8) | ||
| 25th–49th | 814 (24.9) | 285 (25.1) | 299 (26.1) | 230 (23.2) | ||
| 50th–74th | 900 (27.5) | 311 (27.4) | 315 (27.5) | 274 (30.5) | ||
| 75th–90th | 548 (16.7) | 176 (15.5) | 196 (17.1) | 176 (17.8) | ||
| > 90th | 302 (9.2) | 99 (8.7) | 84 (7.3) | 119 (12.0) | ||
| Blood pressure | ||||||
| Systolic blood pressure z score‡ (5th, 95th percentile) | 3255 | −0.6 (−1.3, 0.1) | −0.6 (−1.3, 0.0) | −0.7 (−1.3, 0.0) | −0.6 (−1.2, 0.1) | 0.007 |
| Diastolic blood pressure z score‡ (5th, 95th percentile) | 3252 | 0.1 (−0.4, 0.6) | 0.1 (−0.4, 0.6) | 0.0 (−0.5, 0.5) | 0.1 (−0.4, 0.6) | 0.09 |
| Pre-hypertension (90th–95th) | 3252 | 163 (5.0) | 47 (4.2) | 48 (4.2) | 68 (6.9) | 0.05 |
| Stage 1 or 2 (> 95th) | 114 (3.5) | 37 (3.3) | 40 (3.5) | 37 (3.7) | ||
| Cardiovascular risk¶ | 2919 | 1231 (42.2) | 398 (39.3) | 415 (40.0) | 418 (48.1) | < 0.001 |
Note: BMI = body mass index, HDL = high-density lipoprotein, SD = standard deviation.
↵* Sleep disturbance scores ranged from 0 to 45, with higher scores indicating greater sleep disturbance.
↵† Defined as angina, heart attack, heart or bypass surgery, or stroke before age 65 in women or before age 55 in men.
↵‡ The z score represents how many standard deviations a measurement is above or below the mean value for that measurement in a normal age- and gender-matched population.
↵¶ Defined as non-HDL cholesterol > 3.10mmol/L, BMI > 85th percentile or blood pressure > 90th percentile.