Table 5. Patient characteristics stratified by aggregation test (<70% inhibition of platelet aggregation using collagen 1 μg/ml).
| Variable | Aspirin resistant (n = 156) | Aspirin sensitive (n = 588) | P value |
|---|---|---|---|
| Age (years) | 47.9 (1.2) | 41.9 (1.4) | <0.0001 |
| Women (n, %) | 93, 59.6% | 252, 42.9% | 0.003 |
| Body mass index (kg/m2) | 26.5 (0.4) | 26.5 (0.7) | 0.06 |
| Systolic blood pressure (mmHg) | 121.8 (1.2) | 119.8 (1.6) | 0.89 |
| Diastolic blood pressure (mmHg) | 75.7 (0.7) | 76.5 (1.1) | 0.14 |
| Total cholesterol (mg/dL) | 222 (4) | 205 (8) | 0.03 |
| High density lipoprotein cholesterol (mg/dL) | 58 (1) | 56 (3) | 0.17 |
| Low density lipoprotein cholesterol (mg/dL) | 149 (8) | 137 (4) | 0.07 |
| Triglyceride (mg/dL) | 76 (4) | 66 (7) | 0.99 |
| White blood cell count (103/μL) | 5.32 (0.1) | 5.28 (0.2) | 0.84 |
| Hematocrit | 40.0 (0.2) | 41.2 (0.4) | 0.49 |
| Platelet count (103/μL) | 246.2 (4.0) | 231.3 (10.1) | 0.005 |
| Urinary thromboxane B2 (ng/mg creatinine) (after aspirin administration) | 0.33 (0.02) | 0.27 (0.04) | 0.02 |
| Hypertension medication | 0 | 0.2% | 0.40 |
| Current smoker | 7.1% | 9.9% | 0.81 |
| Menopausal status | 47.3% | 34.9% | 0.89 |
| Hormone use among postmenopausal women | 1.6% | 3.2% | 0.17 |
Mean (SE) or frequency.
Continuous variables were adjusted for age (other than age), sex and family structure; Chi-square test for categorical variables.
P values for triglycerides and thromboxane B2 were based on logarithm or inverse normal transformed values.
Current smokers include pipe, cigar, and cigarette users.