Table 1. The demographic and clinical characteristics of subjects.
| Variables | Initial mono-therapy group (N=32,682) | Initial combination group (N=4,926) | Statistics | P |
|---|---|---|---|---|
| Age (years) | 59.17±11.69 | 58.45±11.33 | t=4.05 | <0.0001 |
| Gender | ||||
| Men | 16,759 (51.28) | 2,775 (56.33) | χ2=43.86 | <0.0001 |
| Women | 15,923 (48.72) | 2,151 (43.67) | ||
| BMI | 24.44±3.22 | 24.88±3.64 | t=8.78 | <0.0001 |
| Baseline blood pressure | ||||
| SBP | 146.12±12.67 | 148.08±14.08 | t=9.97 | <0.0001 |
| DBP | 89.49±8.57 | 90.17±9.58 | t=5.11 | <0.0001 |
| History of illness | ||||
| Myocardial infarction | 145 (0.44) | 29 (0.59) | χ2=1.96 | 0.1620 |
| Angina | 567 (1.73) | 118 (2.40) | χ2=10.45 | 0.0012 |
| Congestive heart failure | 102 (0.31) | 21 (0.43) | χ2=1.71 | 0.1906 |
| Kidney disease | 255 (0.78) | 47 (0.95) | χ2=1.63 | 0.2024 |
| Risk factor | ||||
| Smoking | 5,993 (18.34) | 1,068 (21.78) | χ2=31.38 | <0.0001 |
| Total cholesterol >5.72 mmol/L | 1,147 (4.02) | 212 (4.79) | χ2=7.75 | 0.005 |
| Family history of early onset cardiovascular disease | 1,857 (6.51) | 286 (6.45) | χ2=0.12 | 0.8812 |
| Diabetes | 3,732 (12.96) | 582 (13.06) | χ2=0.66 | 0.417 |
| Target organ damage | ||||
| Left ventricular hypertrophy | 418 (1.28) | 80 (1.63) | χ2=3.90 | 0.0486 |
| Proteinuria or mildly increased plasma creatinine | 383 (1.18) | 83 (1.69) | χ2=9.21 | 0.0024 |
| Carotid ultrasound or X-ray-confirmed atherosclerotic plaque | 1,967 (6.06) | 308 (6.30) | χ2=0.41 | 0.5081 |
| Retinal artery stenosis | 643 (2.08) | 93 (2.00) | χ2=0.14 | 0.7189 |
SBP, systolic blood pressure; DBP, diastolic blood pressure.