Table 1.
The participants’ characteristics, total and by serum Cystatin C level quartile.a
| Variables | Quartile 1 ≤ 0.786 mg/dl (n = 1,214) | Quartile 2 0.786–0.903 mg/dl (n = 1,204) | Quartile 3 0.903–1.07 mg/dl (n = 1,220) | Quartile 4 > 1.07 mg/dl (n = 1,194) | Total (n = 4,832) |
|---|---|---|---|---|---|
| Age, years | 67.1 (6.1) | 69.2 (6.8) | 72.1 (7.5) | 76.3 (7.4) | 71.1 (7.8) |
| Sex, n (%) | |||||
| Male | 534 (44.0%) | 574 (47.7%) | 650 (53.3%) | 634 (53.1%) | 2,392 (49.5%) |
| Female | 680 (56.0%) | 630 (52.3%) | 570 (46.7%) | 560 (46.9%) | 2,440 (50.5%) |
| Race/ethnicity, n (%) | |||||
| Hispanics and others | 446 (36.7%) | 346 (28.7%) | 248 (20.3%) | 182 (15.2%) | 1,222 (25.3%) |
| Non-Hispanic Whites | 544 (44.8%) | 714 (59.3%) | 800 (65.6%) | 900 (75.4%) | 2,958 (61.2%) |
| Non-Hispanic Blacks | 224 (18.5%) | 144 (12.0%) | 172 (14.1%) | 112 (9.4%) | 652 (13.5%) |
| Education, n (%) | |||||
| Below high school | 490 (40.4%) | 456 (38.0%) | 470 (38.6%) | 494 (41.4%) | 1,910 (39.6%) |
| High school graduate | 270 (22.3%) | 300 (25.0%) | 296 (24.3%) | 308 (25.8%) | 1,174 (24.3%) |
| College graduate or above | 452 (37.3%) | 444 (37.0%) | 452 (37.1%) | 392 (32.8%) | 1,740 (36.1%) |
| Serum Cystatin C level, mg/dl | 0.7 (0.07) | 0.8 (0.03) | 1.0 (0.05) | 1.4 (0.70) | 1.0 (0.44) |
| Digit symbol substitution test | 44.9 (19.4) | 45.3 (18.1) | 40.9 (18.6) | 36.3 (16.7) | 41.9 (18.6) |
a
The data for continuous variables were presented as mean (standard deviation), while categorical variables were presented as n (%).