Table 1. Characteristics of Study Sample by Race and Case/Control Status.
| Characteristic* | Caucasians | African Americans | ||||
|---|---|---|---|---|---|---|
| Cases (n = 227) | Controls (n = 667) | P-value | Cases (n = 174) | Controls (n = 383) | P-value | |
| Age, yr | 57.1 (8.0) | 54.5 (8.7) | 0.001 | 58.1 (8.3) | 54.8 (8.6) | 0.001 |
| Sex, % male | 51.5 | 38.4 | 0.001 | 40.2 | 24.8 | 0.001 |
| Body mass index, kg/m2 | 29.0 (6.2) | 27.7 (5.9) | 0.005 | 31.6 (7.9) | 32.1 (7.7) | 0.45 |
| Waist circumference, cm | 39.0 (6.6) | 37.1 (6.3) | 0.001 | 41.4 (7.9) | 40.8 (7.0) | 0.37 |
| Waist-to-hip ratio | 0.92 (0.09) | 0.90 (0.09) | 0.001 | 0.96 (0.09) | 0.93 (0.09) | 0.001 |
| NSAID use | 41.0 | 34.5 | 0.08 | 36.2 | 35.5 | 0.87 |
| Smoking status: | 0.37 | 0.02 | ||||
| Never | 46.3 | 51.1 | 30.5 | 38.9 | ||
| Former | 41.4 | 39.0 | 32.8 | 35.5 | ||
| Current | 12.3 | 9.9 | 36.8 | 25.6 | ||
| Pack years of smoking | 12.2 (26.2) | 14.5 (107.3) | 0.75 | 15.1 (20.6) | 9.9 (23.7) | 0.01 |
| Family history of colorectal cancer, % | 28.2 | 25.2 | 0.37 | 16.1 | 23.8 | 0.04 |
| IL-6, pg/mL | 2.5 (2.1) | 2.2 (1.8) | 0.07 | 3.7 (2.7) | 3.4 (2.3) | 0.10 |
| TNF-α, pg/mL | 5.1 (11.3) | 4.2 (2.5) | 0.23 | 4.5 (2.7) | 4.6 (6.0) | 0.78 |
| Insulin, µIU/mL | 7.5 (11.5) (n = 182) | 6.0 (7.1) (n = 556) | 0.10 | 15.3 (61.5) (n = 129) | 10.0 (14.2) (n = 261) | 0.19 |
| Fasting glucose, mg/dL | 86.3 (17.3) (n = 184) | 85.3 (24.6) (n = 569) | 0.59 | 97.9 (29.1) (n = 129) | 94.2 (37.5) (n = 262) | 0.33 |
*
Values for continuous variables are mean (SD); for categorical variables, values are for percentages. Two-sided comparisons were computed using independent samples t-tests for continuous and by χ square test for categorical variables.