Table 1.
Population characteristics at the midlife baseline (visit 1, n=14,462)
| Overall | Quintile 1 | Quintile 2 | Quintile 3 | Quintile 4 | Quintile 5 | P-value | |
|---|---|---|---|---|---|---|---|
| Range of circulating protein C levels, ug/mL | 0.7, 9.6 | 0.7, 2.6 | 2.7, 2.9 | 3.0, 3.2 | 3.3, 3.6 | 3.7, 9.6 | |
| Variable | |||||||
| N | 14,462 | 2809 | 2738 | 3011 | 2963 | 2941 | |
| Age, year, mean (SD) | 54.2 (5.8) | 53.8 (5.9) | 53.9 (5.9) | 54.1 (5.8) | 54.5 (5.7) | 54.6 (5.5) | <0.001 |
| Male, n (%) | 6486 (44.9) | 1594 (56.7) | 1397 (51) | 1368 (45.4) | 1208 (40.8) | 919 (31.2) | <0.001 |
| Self-reported black, n (%) | 3784 (26.2) | 846 (30.1) | 680 (24.8) | 757 (25.1) | 731 (24.7) | 770 (26.2) | <0.001 |
| APOE ε4 1 or 2 copies, n (%) | 4452 (30.8) | 913 (32.5) | 836 (30.5) | 885 (29.4) | 911 (30.7) | 907 (30.8) | 0.15 |
| Education, year, n (%) | <0.001 | ||||||
| < High school | 3399 (23.5) | 684 (24.4) | 629 (23) | 698 (23.2) | 658 (22.2) | 730 (24.8) | |
| High school graduate or vocational school | 5921 (40.9) | 1092 (38.9) | 1069 (39) | 1218 (40.5) | 1278 (43.1) | 1264 (43) | |
| College, graduate or professional school | 5142 (35.6) | 1033 (36.8) | 1040 (38) | 1095 (36.4) | 1027 (34.7) | 947 (32.2) | |
| BMI, kg/m2, mean (SD) | 27.7 (5.3) | 26.9 (5.2) | 27.6 (5.3) | 27.7 (5.3) | 27.9 (5.5) | 28.3 (5.3) | <0.001 |
| Current smoker, n (%) | 3775 (26.1) | 918 (32.7) | 745 (27.2) | 802 (26.6) | 687 (23.2) | 623 (21.2) | <0.001 |
| Prevalent diabetes, n (%) | 1701 (11.8) | 277 (9.9) | 288 (10.5) | 287 (9.5) | 344 (11.6) | 505 (17.2) | <0.001 |
| Prevalent hypertension, n (%) | 4995 (34.5) | 844 (30) | 877 (32) | 1003 (33.3) | 1042 (35.2) | 1229 (41.8) | <0.001 |
| Prevalent stroke, n (%) | 236 (1.6) | 51 (1.8) | 34 (1.2) | 45 (1.5) | 42 (1.4) | 64 (2.2) | 0.04 |
| Prevalent atrial fibrillation, n (%) | 25 (0.18) | 9 (0.3) | 4 (0.1) | 5 (0.2) | 5 (0.2) | 2 (0.1) | 0.27 |
| eGFR, mL/min/1.73m2, mean (SD) | 102.4 (15.8) | 103.8 (15.8) | 101.9 (15.3) | 102 (15.9) | 102.1 (15.1) | 102.4 (16.5) | <0.001 |
| Platelet count, K/uL, median (25th, 75th percentile) | 251 (214, 295) | 238 (200, 281) | 243 (208.25, 285) | 252 (216, 293) | 256 (219, 300) | 267 (228, 309) | <0.001 |
| Factor VIIIc, % | 126 (105, 151) | 122 (101, 147) | 123 (104, 148) | 126 (105, 150) | 128 (107, 151) | 132 (109, 158) | <0.001 |
| Fibrinogen, mg/dL | 295 (260, 337) | 290 (254, 331) | 290 (256, 332) | 295 (260.5, 337) | 297 (262, 341) | 302 (267, 345) | <0.001 |
| von Willebrand factor, % | 110 (84, 142) | 106 (80, 138) | 107 (82, 138) | 109 (83, 140) | 111 (86, 145) | 115 (89, 151) | <0.001 |
Abbreviation. BMI, body mass index; eGFR, estimated glomerular filtration rate; factor VIIIc, factor VIII activity P-values were obtained by comparing the values among the quintiles of protein C: Chi-squared test was used for categorical variables with at least 5 observations in all cells, otherwise Fisher-exact test was used; one-way ANOVA was used for non-skewed variables and Kruskal-Wallis test was used for skewed variables