Table 1. Baseline characteristics of coronary heart disease cases and matched controls in the Reykjavik Study, and correlations with t-PA antigen, D-dimer and VWF.
| Variable | Summary of baseline values | Cross-sectional correlation with hemostatic markers | ||||||
| Cases | Controls | P value | Adjusted percentage difference (95% CI)† | |||||
| n | Mean (SD), median (IQR),or n (%) | n | Mean (SD), median (IQR),or n (%) | t-PA antigen | D-dimer | VWF | ||
| Questionnaire-based | ||||||||
| Age, years | 1925 | 54.2 (8.7) | 3616 | 55.2 (9.0) | Matched | 8% (6 to 11) | 24% (19 to 29) | 9% (7 to 11) |
| Male sex | 1925 | 1347 (70%) | 3616 | 2441 (68%) | Matched | 23% (19 to 27) | −28% (−33 to −23) | 3% (1 to 6) |
| Current smoker | 1925 | 1153 (60%) | 3616 | 1751 (48%) | <0.0001 | 4% (1 to 7) | 7% (0 to 14) | 5% (3 to 8) |
| History of diabetes | 1925 | 51 (3%) | 3616 | 58 (2%) | 0.011 | −3% (−15 to 10) | −10% (−30 to 15) | 6% (−5 to 17) |
| Physical measurements | ||||||||
| Body mass index, kg/m2 | 1925 | 26.0 (3.9) | 3616 | 25.4 (3.7) | <0.0001 | 20% (18 to 21) | −16% (−18 to −13) | 1% (0 to 2) |
| Systolic blood pressure, mmHg | 1925 | 146.7 (21.7) | 3616 | 141.9 (20.1) | <0.0001 | 11% (9 to 13) | −6% (−9 to −3) | 1% (0 to 3) |
| Diastolic blood pressure, mmHg | 1924 | 90.2 (11.0) | 3615 | 87.5 (10.8) | <0.0001 | 13% (12 to 15) | −8% (−11 to −5) | 1% (−1 to 2) |
| Lipid markers | ||||||||
| Total cholesterol, mmol/L | 1925 | 6.9 (1.2) | 3616 | 6.4 (1.1) | <0.0001 | 7% (5 to 9) | −5% (−8 to −2) | 0% (−1 to 1) |
| Triglycerides, mmol/L* | 1925 | 1.1 (0.9−1.5) | 3616 | 1.0 (0.8−1.4) | <0.0001 | 21% (19 to 23) | −14% (−17 to −11) | 2% (0 to 3) |
| Lipoprotein(a), mg/L* | 1917 | 115 (39−283) | 3612 | 82 (25−199) | <0.0001 | −3% (−5 to −2) | 1% (−2 to 4) | 0% (−1 to 1) |
| Inflammatory markers | ||||||||
| Interleukin 6, ng/L* | 1658 | 2.1 (1.4–3.4) | 3060 | 1.9 (1.2–2.9) | <0.0001 | 5% (4 to 7) | 13% (9 to 17) | 5% (4 to 6) |
| C-reactive protein, mg/L* | 1906 | 1.7 (0.8–3.5) | 3573 | 1.2 (0.6–2.7) | <0.0001 | 13% (11 to 14) | 6% (3 to 9) | 8% (7 to 9) |
| Rheological markers | ||||||||
| Hematocrit, % | 1925 | 44.7 (4.7) | 3616 | 44.1 (4.5) | <0.0001 | 10% (9 to 12) | −8% (−12 to −5) | 0% (−2 to 1) |
| Hemoglobin, g/L | 1917 | 148.3 (13.1) | 3599 | 145.9 (13.1) | <0.0001 | 16% (14 to 18) | −14% (−17 to −11) | 1% (−1 to 2) |
| ESR, mm/hr* | 1838 | 8.0 (4.0–15.0) | 3427 | 7.0 (3.0–13.0.) | <0.0001 | 3% (1 to 5) | 16% (12 to 20) | 9% (7 to 10) |
| Hemostatic markers | ||||||||
| t-PA antigen, ng/mL* | 1925 | 13.9 (9.9–18.8) | 3616 | 12.6 (8.8–17.2) | <0.0001 | – | −15% (−18 to −12) | 6% (5 to 8) |
| D-dimer, ng/mL* | 1925 | 115 (60–246) | 3616 | 121 (64–241) | 0.280 | −8% (−10 to −7) | – | 7% (6 to 8) |
| VWF, IU/dL* | 1925 | 107 (81–141) | 3616 | 106 (78–136) | 0.008 | 7% (6 to 9) | 17% (14 to 21) | – |
| Others | ||||||||
| Serum creatinine (µmol/L) | 1907 | 77 (20) | 3587 | 75 (13) | <0.001 | 7% (5 to 9) | 0% (−4 to 3) | 3% (1 to 5) |
Abbreviations: ESR, erythrocyte sedimentation rate; IQR, inter-quartile range.
*
Means (SDs) of loge transformed values in cases and controls were 0.2 (0.5) and 0.0 (0.4) for triglycerides; 4.4 (1.6) and 4.0 (1.7) for lipoprotein (a); 0.8 (0.8) and 0.7 (0.8) for interleukin 6; 0.5 (1.1) and 0.2 (1.1) for C-reactive protein; 2.0 (1.0) and 1.9 (1.0) for erythrocyte sedimentation rate; 2.6 (0.5) and 2.5 (0.5) for t-PA antigen; 4.8 (1.0) and 4.8 (1.0) for D-dimer; and 4.7 (0.4) and 4.6 (0.4) for VWF.
†
Percentage differences and 95% CIs were calculated per 1 SD higher level or compared to the reference category of variables shown in the left column (adjusted for age, sex and period of recruitment).