Table 1.
Baseline characteristics according to different levels of serum calcium among patients with coronary heart disease
| Characteristics | Serum calcium (mmol/L) | P value | |||
|---|---|---|---|---|---|
| <2.18 | 2.18–2.27 | 2.28–2.36 | ≥2.37 | ||
| Male (%) | 70.3 | 63.4 | 62.6 | 55.4 | <0.001 |
| Age (years) | 65.8 (0.39) | 64.7 (0.38) | 63.2 (0.40) | 62.9 (0.39) | <0.001 |
| Serum phosphorus (mmol/L) | 1.13 (0.01) | 1.14 (0.01) | 1.17 (0.01) | 1.21 (0.01) | <0.001 |
| Body mass index (kg/m2) | 23.6 (0.12) | 23.8 (0.12) | 24.1 (0.12) | 24.5 (0.12) | <0.001 |
| Systolic blood pressure (mmHg) | 131 (0.77) | 134 (0.76) | 138 (0.79) | 139 (0.77) | <0.001 |
| Diastolic blood pressure (mmHg) | 75.3 (0.45) | 77.8 (0.44) | 79.0 (0.45) | 80.4 (0.44) | <0.001 |
| Low-density lipoprotein cholesterol (mmol/L) | 2.88 (0.04) | 3.00 (0.03) | 3.04 (0.04) | 3.04 (0.03) | 0.002 |
| High-density lipoprotein cholesterol (mmol/L) | 1.06 (0.01) | 1.13 (0.01) | 1.17 (0.01) | 1.21 (0.01) | <0.001 |
| Triglycerides (mmol/L) | 1.64 (0.05) | 1.85 (0.05) | 1.92 (0.05) | 1.98 (0.05) | <0.001 |
| Total cholesterol (mmol/L) | 4.54 (0.04) | 4.78 (0.04) | 4.89 (0.04) | 4.97 (0.04) | <0.001 |
| Fasting glucose (mmol/L) | 6.71 (0.10) | 6.41 (0.10) | 6.60 (0.10) | 6.71 (0.10) | 0.12 |
| Estimated glomerular filtration rate (mL/min per 1.73 m2, %) | <0.001 | ||||
| ≥90 | 17.8 | 22.9 | 23.7 | 20.3 | |
| 60–89 | 48.9 | 46.2 | 52.2 | 53.8 | |
| 30–59 | 28.6 | 29.3 | 23.1 | 24.6 | |
| <30 | 4.8 | 1.6 | 1.1 | 1.2 | |
| Types of coronary heart disease (%) | <0.001 | ||||
| Acute coronary syndrome | 65.9 | 57.7 | 51.5 | 51.7 | |
| Stable coronary heart disease | 34.1 | 42.3 | 48.5 | 48.3 | |
| Married (%) | 70.7 | 75.8 | 79.4 | 85.8 | <0.001 |
| Years of education (%) | 0.61 | ||||
| ≤9 | 68.3 | 67.1 | 66.3 | 67.6 | |
| 10–12 | 17.5 | 15.0 | 15.5 | 15.7 | |
| ≥13 | 14.3 | 17.9 | 18.2 | 16.7 | |
| Smoking (%) | 0.006 | ||||
| Never | 58.4 | 60.3 | 61.6 | 66.1 | |
| Past | 8.7 | 9.8 | 11.0 | 10.0 | |
| Current | 32.8 | 29.9 | 27.4 | 23.9 | |
| Alcohol drinking (%) | 0.001 | ||||
| Never | 80.3 | 82.7 | 84.7 | 88.1 | |
| Past | 5.1 | 5.8 | 4.1 | 2.6 | |
| Current | 14.6 | 11.5 | 11.2 | 9.3 | |
| Leisure-time physical activity (%) | <0.001 | ||||
| None | 22.8 | 18.3 | 13.4 | 10.1 | |
| <30 min/day | 11.6 | 11.7 | 11.1 | 7.6 | |
| ≥30 min/day | 29.0 | 24.5 | 21.1 | 14.7 | |
| No data | 36.5 | 45.5 | 54.3 | 67.6 | |
| History of diseases (%) | |||||
| Hypertension | 81.0 | 76.5 | 75.9 | 72.9 | 0.002 |
| Diabetes | 23.8 | 22.4 | 21.7 | 25.4 | 0.33 |
| Uses of medications before admission (%) | |||||
| Antihypertensive medication | 45.3 | 49.3 | 54.0 | 54.1 | 0.001 |
| Glucose-lowering medication | 14.9 | 16.3 | 16.5 | 19.7 | 0.07 |
| Lipid-lowering medication | 7.3 | 11.3 | 13.0 | 12.0 | 0.003 |
| Antiplatelet medication | 13.6 | 17.7 | 16.2 | 15.1 | 0.17 |
The values are mean (SE) or percentage. Continuous variables are adjusted for age, except for age