Background
Methods
Study population
Data collection and measurements
Definitions
Statistical analysis
Results
Baseline characteristics of study population
Variables | QTc ≤ 440 ms (n = 7666) | QTc > 440 ms (n = 3543) | P-value |
---|---|---|---|
Age (year) | 53 ± 10 | 56 ± 11 | < 0.001* |
Male gender | 4063 (53.0) | 1043 (29.4) | < 0.001* |
Race of Han | 7250 (94.6) | 3380 (95.4) | 0.066 |
Current smoking status | 2915 (38.0) | 1028 (29.0) | < 0.001* |
Current drinking status | 1981 (25.8) | 520 (14.7) | < 0.001* |
Education | < 0.001* | ||
Primary school or below | 3603 (47.0) | 1987 (56.1) | |
Middle school | 3326 (43.4) | 1254 (35.4) | |
High school or above | 737 (9.6) | 302 (8.5) | |
Physical activity | < 0.001* | ||
Low | 2013 (26.3) | 1278 (36.1) | |
Moderate | 5210 (68.0) | 2076 (58.6) | |
High | 443 (5.8) | 189 (5.3) | |
Family income (CNY/year) | < 0.001* | ||
≤ 5000 | 876 (11.4) | 513 (14.5) | |
5000–20,000 | 4179 (54.5) | 1952 (55.1) | |
> 20,000 | 2611 (34.1) | 1078 (30.4) | |
SBP (mmHg) | 138.9 ± 22.1 | 148.0 ± 25.2 | < 0.001* |
DBP (mmHg) | 80.9 ± 11.1 | 84.4 ± 12.7 | < 0.001* |
BMI (kg/m2) | 24.6 ± 3.6 | 25.2 ± 3.8 | < 0.001* |
WC (cm) | 81.9 ± 9.7 | 83.6 ± 9.9 | < 0.001* |
TC (mmol/L) | 5.2 ± 1.1 | 5.4 ± 1.2 | < 0.001* |
TG (mmol/L) | 1.6 ± 1.4 | 1.8 ± 1.7 | < 0.001* |
LDL-C (mmol/L) | 2.9 ± 0.8 | 3.0 ± 0.9 | < 0.001* |
HDL-C (mmol/L) | 1.4 ± 0.4 | 1.4 ± 0.4 | 0.014* |
FPG (mmol/L) | 5.8 ± 1.4 | 6.2 ± 2.1 | < 0.001* |
Calcium (mmol/L) | 2.3 ± 0.1 | 2.3 ± 0.1 | < 0.001* |
Potassium (mmol/L) | 4.2 ± 0.3 | 4.1 ± 0.4 | < 0.001* |
Magnesium (mmol/L) | 0.8 ± 0.1 | 0.8 ± 0.1 | 0.119 |
History of heart diseasea | 647 (8.4) | 451 (12.7) | < 0.001* |
Medication usedb | 3806 (49.6) | 2122 (59.9) | < 0.001* |
Prevalence of prolonged QTc interval
Age (year) | Sample size | Mean QTc (ms) | Prevalence of prolonged QTc | Prevalence of prolonged QTc adjusted for sex | |||
---|---|---|---|---|---|---|---|
Male | Female | Male | Female | Male> 450 | Female> 470 | ||
35–44 | 2699 | 415.4 ± 21.7 | 431.6 ± 23.2 | 149 (12.6) | 502 (33.0) | 80 (6.8) | 62 (4.1) |
45–54 | 3481 | 419.3 ± 23.3 | 434.4 ± 22.1 | 256 (16.7) | 730 (37.5) | 140 (9.1) | 106 (5.4) |
55–64 | 3371 | 424.7 ± 24.6 | 438.6 ± 23.6 | 358 (22.9) | 829 (45.8) | 191 (12.2) | 135 (7.5) |
≥65 | 1658 | 431.8 ± 24.5 | 443.3 ± 24.5 | 280 (33.5) | 439 (53.3) | 180 (21.6) | 92 (11.2) |
Factors associated with prolonged QTc interval
Variables | ORs | 95% CIs | P-value |
---|---|---|---|
Age (per 10 year increase) | 1.228 | 1.168–1.290 | < 0.001* |
Female gender | 2.878 | 2.564–3.229 | < 0.001* |
Race of Hana | 1.196 | 0.981–1.458 | 0.076 |
Current smoking status | 1.075 | 0.970–1.191 | 0.166 |
Current drinking status | 0.938 | 0.821–1.071 | 0.344 |
Education | |||
Primary school or below | 1.000 (reference) | ||
Middle school | 1.075 | 0.974–1.186 | 0.151 |
High school or above | 1.157 | 0.986–1.357 | 0.073 |
Physical activity | |||
Low | 1.000 (reference) | ||
Moderate | 0.925 | 0.840–1.018 | 0.11 |
High | 0.832 | 0.685–1.011 | 0.064 |
Family income (CNY/year) | |||
≤ 5000 | 1.000 (reference) | ||
5000–20,000 | 0.931 | 0.815–1.064 | 0.294 |
> 20,000 | 0.926 | 0.799–1.072 | 0.302 |
General obesity | 1.043 | 0.916–1.187 | 0.528 |
Abdominal obesity | 1.156 | 1.010–1.324 | 0.035* |
Hypertension | 1.838 | 1.675–2.016 | < 0.001* |
Diabetes | 1.593 | 1.391–1.824 | < 0.001* |
High TC | 0.977 | 0.847–1.127 | 0.747 |
High TG | 1.241 | 1.104–1.395 | 0.001* |
High LDL-C | 1.112 | 0.919–1.347 | 0.276 |
Low HDL-C | 1.119 | 0.980–1.278 | 0.096 |
Calcium (mmol/L) < 1.875 | 0.667 | 0.178–2.497 | 0.547 |
Potassium (mmol/L) < 3.5 | 2.636 | 1.806–3.846 | < 0.001* |
Magnesium (mmol/L) < 0.7 | 0.746 | 0.200–2.789 | 0.664 |
History of heart diseaseb | 1.065 | 0.927–1.223 | 0.375 |
Medication usedc | 1.131 | 1.036–1.234 | 0.006* |
Variables | ORs | 95% CIs | P-value |
---|---|---|---|
Age (per 10 year increase) | 1.216 | 1.127–1.311 | < 0.001* |
Female gender | 2.995 | 2.502–3.584 | < 0.001* |
Race of Hana | 1.260 | 0.944–1.682 | 0.117 |
Current smoking status | 0.948 | 0.808–1.112 | 0.511 |
Current drinking status | 1.020 | 0.842–1.237 | 0.836 |
Education | |||
Primary school or below | 1.000 (reference) | ||
Middle school | 1.086 | 0.936–1.261 | 0.276 |
High school or above | 1.294 | 1.029–1.626 | 0.027* |
Physical activity | |||
Low | 1.000 (reference) | ||
Moderate | 0.879 | 0.756–1.023 | 0.096 |
High | 0.702 | 0.525–0.939 | 0.017* |
Family income (CNY/year) | |||
≤ 5000 | 1.000 (reference) | ||
5000–20,000 | 1.024 | 0.824–1.273 | 0.828 |
> 20,000 | 1.105 | 0.876–1.393 | 0.401 |
General obesity | 1.089 | 0.891–1.330 | 0.407 |
Abdominal obesity | 1.264 | 1.019–1.567 | 0.033* |
Hypertension | 1.933 | 1.680–2.224 | < 0.001* |
Diabetes | 1.856 | 1.469–2.346 | < 0.001* |
High TC | 0.987 | 0.793–1.229 | 0.909 |
High TG | 1.172 | 0.973–1.413 | 0.094 |
High LDL-C | 1.142 | 0.843–1.547 | 0.391 |
Low HDL-C | 1.214 | 0.987–1.492 | 0.066 |
Calcium (mmol/L) < 1.875 | 0.603 | 0.071–5.106 | 0.642 |
Potassium (mmol/L) < 3.5 | 2.224 | 1.118–4.426 | 0.023* |
Magnesium (mmol/L) < 0.7 | 1.893 | 0.323–11.098 | 0.479 |
History of heart diseaseb | 0.916 | 0.697–1.204 | 0.529 |
Variables | ORs | 95% CIs | P-value |
---|---|---|---|
Age (per 10 year increase) | 1.257 | 1.164–1.357 | < 0.001* |
Female gender | 0.497 | 0.416–0.594 | < 0.001* |
Race of Hana | 0.827 | 0.617–1.109 | 0.205 |
Current smoking status | 1.015 | 0.870–1.184 | 0.847 |
Current drinking status | 1.085 | 0.905–1.300 | 0.379 |
Education | |||
Primary school or below | 1.000 (reference) | ||
Middle school | 1.010 | 0.862–1.184 | 0.900 |
High school or above | 1.014 | 0.784–1.312 | 0.916 |
Physical activity | |||
Low | 1.000 (reference) | ||
Moderate | 0.896 | 0.768–1.046 | 0.164 |
High | 0.652 | 0.462–0.921 | 0.015* |
Family income (CNY/year) | |||
≤ 5000 | 1.000 (reference) | ||
5000–20,000 | 0.883 | 0.728–1.073 | 0.211 |
> 20,000 | 0.848 | 0.680–1.059 | 0.146 |
General obesity | 1.097 | 0.842–1.430 | 0.493 |
Abdominal obesity | 1.191 | 0.950–1.493 | 0.130 |
Hypertension | 2.357 | 2.001–2.775 | < 0.001* |
Diabetes | 1.638 | 1.362–1.970 | < 0.001* |
High TC | 0.865 | 0.689–1.087 | 0.214 |
High TG | 1.231 | 1.033–1.467 | 0.020* |
High LDL-C | 1.111 | 0.826–1.495 | 0.486 |
Low HDL-C | 1.143 | 0.937–1.394 | 0.187 |
Calcium (mmol/L) < 1.875 | 0.830 | 0.103–6.713 | 0.861 |
Potassium (mmol/L) < 3.5 | 1.957 | 1.230–3.114 | 0.005* |
Magnesium (mmol/L) < 0.7 | 0.590 | 0.072–4.860 | 0.624 |
History of heart diseaseb | 1.375 | 1.126–1.678 | 0.002* |
Medication usedc | 1.253 | 1.085–1.448 | 0.002* |