Table 2.
Characteristics of subjects by baseline Cystatin C quartiles
| Characteristic | Cyst-C | Cyst-C | Cyst-C | Cyst-C | p-value* |
|---|---|---|---|---|---|
| <0.83 mg/dL | 0.83-0.94 mg/dL | 0.95-1.12 mg/dL | >1.12 mg/dL | ||
| (n=7,146) | (n=6,732) | (n=7,031) | (n=6,757) | ||
| DEMOGRAPHICS | |||||
| Age mean (SD) | 59.8 (8.0) | 63.3 (8.4) | 66.2 (8.8) | 70.3 (9.1) | <0.001 |
| Sex (%) | <0.001 | ||||
| Male | 59.1 | 45.9 | 48.8 | 46.6 | |
| Female | 41.0 | 54.1 | 51.2 | 53.4 | |
| Race (%) | <0.001 | ||||
| White | 52.9 | 60.2 | 63.5 | 61.6 | |
| Black | 47.1 | 39.8 | 36.6 | 38.5 | |
| Education (%) | |||||
| Less than high school | 8.8 | 10.2 | 12.8 | 17.4 | |
| High school graduate | 23.6 | 24.8 | 26.3 | 28.7 | |
| Some college | 26.3 | 27.0 | 27.0 | 27.0 | |
| College or higher | 41.3 | 38.0 | 33.8 | 27.0 | |
| Missing N (%) | 1 (0.0) | 6 (0.1) | 4 (0.1) | 10 (0.2) | |
| Income (%) | <0.001 | ||||
| <$20 k | 14.8 | 17.2 | 20.9 | 28.1 | |
| $20k-$34 k | 22.8 | 25.3 | 28.5 | 33.7 | |
| $35k-$74 k | 36.3 | 35.3 | 35.0 | 29.7 | |
| ≥$75 k | 26.2 | 22.2 | 15.6 | 8.5 | |
| Missing N (%) | 812 (11.4) | 795 (11.8) | 882 (12.5) | 879 (13.0) | |
| Geographic region (%) | 0.012 | ||||
| Non-belt/buckle | 44.4 | 45.3 | 43.3 | 44.3 | |
| Stroke belt | 35.4 | 33.6 | 36.1 | 34.0 | |
| Stroke buckle | 20.2 | 21.1 | 20.6 | 21.8 | |
| HEALTH BEHAVIORS | |||||
| Tobacco Use (%) | <0.001 | ||||
| Current | 12.9 | 14.5 | 15.1 | 15.4 | |
| Past | 38.4 | 39.6 | 41.6 | 42.1 | |
| Never | 48.7 | 45.9 | 43.3 | 42.5 | |
| Missing N (%) | 33 (0.5) | 24 (0.4) | 25 (0.4) | 19 (0.3) | |
| Alcohol use (%) | <0.001 | ||||
| Heavy | 5.8 | 4.6 | 3.6 | 2.2 | |
| Moderate | 40.1 | 36.3 | 32.2 | 25.4 | |
| None | 54.1 | 59.1 | 64.2 | 72.5 | |
| Missing N (%) | 134 (1.9) | 124 (1.8) | 128 (1.8) | 157 (2.3) | |
| CHRONIC MEDICAL CONDITIONS | |||||
| Cancer (%) | 6.2 | 7.4 | 9.5 | 12.1 | <0.001 |
| Chronic lung disease (%) | 7.3 | 8.4 | 9.1 | 11.8 | <0.001 |
| Coronary artery disease (%) | 10.2 | 13.3 | 18.1 | 30.2 | <0.001 |
| Diabetes (%) | 17.4 | 18.1 | 20.5 | 33.1 | <0.001 |
| Dyslipidemia (%) | 49.7 | 56.1 | 61.9 | 67.7 | <0.001 |
| Hypertension (%) | 45.8 | 52.7 | 61.5 | 76.8 | <0.001 |
| Myocardial infarction (%) | 7.6 | 9.5 | 12.7 | 21.2 | <0.001 |
| Obesity (%) | 43.7 | 50.2 | 56.1 | 62.9 | <0.001 |
| Stroke (%) | 3.4 | 4.1 | 6.0 | 11.4 | <0.001 |
| BIOMARKERS | |||||
| Serum creatinine-based estimated glomerular filtration rate (eGFR) <60 mg/min/1.73m2 (%) | 0.3 | 1.0 | 4.5 | 40.7 | <0.001 |
| Missing N (%) | 6 (0.1) | 7 (0.1) | 6 (0.1) | 11 (0.2) | |
| Urinary albumin-to-creatinine ratio (ACR) ≥30 mg/g | 9.0 | 9.4 | 12.7 | 29.7 | <0.001 |
| Missing N (%) | 193 (2.7) | 202 (3.0) | 220 (3.1) | 333 (4.9) | |
| Serum high-sensitivity C-reactive protein (hsCRP) >3.0 mg/dL | 31.9 | 36.3 | 42.9 | 51.8 | <0.001 |
| Missing N (%) | 4 (0.1) | 3 (0.4) | 6 (0.1) | 4 (0.1) |
*Based on chi-square test for categorical variables and t-test for continuous variables. Based on 29,696 participants with follow-up data available. 2,030 (6.8%) missing Cystatin C measurement.