Table 1.
Baseline characteristics by quartile of directly measured small dense LDL cholesterol
| Total | sd-LDL-C 1st quartile | sd-LDL-C 2nd quartile | sd-LDL-C 3rd quartile | sd-LDL-C 4th quartile | P-value | |
|---|---|---|---|---|---|---|
| n = 4672 | n = 1168 | n = 1168 | n = 1168 | n = 1168 | ||
| Range, mg/dL | 0.1, 26.2 | 26.2, 35.6 | 35.6, 48.9 | 49.0, 214.8 | — | |
| Age, years | 61.9 (10.4) | 62.2 (10.9) | 62.2 (10.4) | 62.5 (10.3) | 60.8 (9.8) | <0.001 |
| Women, n (%) | 2453 (52.5) | 648 (55.5) | 680 (58.2) | 570 (48.8) | 555 (47.5) | <0.001 |
| Race/ethnicity, n (%) | <0.001 | |||||
| White | 1707 (36.5) | 413 (35.4) | 444 (38.0) | 420 (36.0) | 430 (36.8) | |
| Chinese-American | 559 (12.0) | 117 (10.0) | 125 (10.7) | 142 (12.2) | 175 (15.0) | |
| Black | 1343 (28.7) | 457 (39.1) | 375 (32.1) | 313 (26.8) | 198 (17.0) | |
| Hispanic | 1063 (22.8) | 181 (15.5) | 224 (19.2) | 293 (25.1) | 365 (31.3) | |
| Educational attainment, ≥high school, n (%) | 3787 (81.3) | 999 (86.2) | 964 (82.8) | 937 (80.4) | 887 (76.2) | <0.001 |
| Hypertension, n (%) | 1950 (41.7) | 455 (39.0) | 477 (40.8) | 528 (45.2) | 490 (42.0) | 0.019 |
| Diabetes, n (%) | 1185 (25.4) | 211 (18.1) | 261 (22.3) | 335 (28.7) | 378 (32.4) | <0.001 |
| Current cigarette use, n (%) | 607 (13.0) | 167 (14.3) | 133 (11.4) | 158 (13.5) | 149 (12.8) | 0.189 |
| Body mass index, kg/m2 | 28.3 (5.5) | 27.5 (5.9) | 28.0 (5.6) | 28.5 (5.3) | 28.8 (5.1) | <0.001 |
| HDL-C, mg/dL | 51.1 (15.1) | 56.6 (15.9) | 53.8 (15.2) | 49.1 (14.6) | 45.1 (11.5) | <0.001 |
| Triglycerides, log(U) | 4.7 (0.5) | 4.3 (0.4) | 4.5 (0.4) | 4.8 (0.4) | 5.2 (0.4) | <0.001 |
| Estimated total LDL-C, mg/dL | ||||||
| Friedewald equation | 119.7 (31.4) | 94.4 (22.8) | 116.0 (21.5) | 126.4 (26.5) | 142.6 (32.5) | <0.001 |
| Martin–Hopkins equation | 121.4 (31.1) | 93.6 (22.2) | 116.2 (19.6) | 128.5 (24.3) | 147.3 (29.8) | <0.001 |
| Sampson–NIH equation | 122.1 (31.7) | 95.4 (23.2) | 118.1 (21.0) | 129.4 (26.2) | 145.3 (32.0) | <0.001 |
| Prevalent CAC, n (%) | 2212 (47.3) | 467 (40.0) | 524 (44.9) | 616 (52.7) | 605 (51.8) | <0.001 |
Values displayed are mean (standard deviation) for normally distributed continuous variables or total number (%) for categorical variables.
CAC, coronary artery calcification; HDL-C, HDL cholesterol; NIH, National Institutes of Health; sd-LDL-C, small dense LDL cholesterol; LDL-C, LDL cholesterol.