Table 2. Baseline variables by quartile of baseline cystatin C.
| Variable | All participants (n = 1,732) | Participants by cystatin C quartile | P value for trend | |||
|---|---|---|---|---|---|---|
| Quartile 1 (n = 444) | Quartile 2 (n = 432) | Quartile 3 (n = 431) | Quartile 4 (n = 425) | |||
| eGFRcreat (ml/min/1.73 m2) | 53.6 ± 11.8 | 63.6 ± 9.7 | 57.4 ± 7.4 | 51.1 ± 8.1 | 41.7 ± 8.9 | <0.001 |
| eGFRcys (ml/min/1.73 m2) | 45.1 ± 16.0 | 65.5 ± 14.4 | 47.7 ± 3.8 | 38.6 ± 3.0 | 27.9 ± 4.9 | <0.001 |
| eGFRcreat-cys (ml/min/1.73 m2) | 48.3 ± 12.9 | 64.0 ± 9.2 | 51.7 ± 4.3 | 43.7 ± 4.3 | 33.2 ± 5.7 | <0.001 |
| Age (years) | 72.9 + 9.0 | 68.6 ± 9.0 | 72.2 ± 8.3 | 74.4 ± 8.1 | 76.4 ± 8.8 | 0.19 |
| Female sex | 1,047 (60.4%) | 350 (78.8%) | 270 (62.5%) | 230 (53.4%) | 197 (46.4%) | <0.001 |
| Diabetes | 292 (16.9%) | 43 (9.7%) | 60 (13.9%) | 92 (21.3%) | 97 (22.8%) | <0.001 |
| Current smoker | 81 (4.7%) | 17 (3.8%) | 18 (4.2%) | 18 (4.2%) | 28 (6.6%) | 0.20 |
| Previous CVD | 385 (22.2%) | 67 (15.1%) | 84 (19.4%) | 111 (25.8%) | 123 (28.9%) | <0.001 |
| Thyroid disorder | 217 (12.5%) | 61 (13.7%) | 58 (13.4%) | 44 (10.2%) | 54 (12.7%) | 0.39 |
| Haemoglobin (g/l) | 132 ± 14 | 135 ± 13 | 134 ± 13 | 133 ± 14 | 128 ± 16 | <0.001 |
| Corrected calcium (mmol/l) | 2.38 ± 0.10 | 2.38 ± 0.10 | 2.38 ± 0.09 | 2.38 ± 0.10 | 2.37 ± 0.10 | 0.37 |
| Phosphate (mmol/l) | 1.11 ± 0.18 | 1.11 ± 0.18 | 1.10 ± 0.19 | 1.09 ± 0.16 | 1.12 ± 0.18 | 0.07 |
| Albumin (g/l) | 40.7 ± 3.2 | 41.3 ± 3.0 | 41.0 ± 3.0 | 40.4 ± 3.1 | 40.0 ± 3.5 | 0.28 |
| Bicarbonate (mmol/l) | 25.5 ± 2.7 | 26.1 ± 2.4 | 25.7 ± 2.5 | 25.4 ± 2.7 | 24.9 ± 3.0 | <0.001 |
| Total cholesterol (mmol/l) | 4.8 ± 1.2 | 5.1 ± 1.1 | 4.8 ± 1.1 | 4.7 ± 1.2 | 4.5 ± 1.2 | 0.04 |
| Uric acid (μmol/l) | 384 ± 91 | 334 ± 75 | 364 ± 76 | 398 ± 78 | 443 ± 96 | <0.001 |
| BMI (kg/m2) | 29.0 ± 5.1 | 28.4 ± 4.9 | 28.7 ± 4.7 | 29.3 ± 4.8 | 29.7 ± 5.9 | 0.003 |
| Waist-to-hip ratio | 0.91 ± 0.09 | 0.87 ± 0.08 | 0.90 ± 0.09 | 0.92 ± 0.08 | 0.94 ± 0.09 | 0.001 |
| SBP (mm Hg) | 134 ± 18 | 133 ± 18 | 134 ± 17 | 135 ± 18 | 134 ± 21 | 0.001 |
| DBP (mm Hg) | 73 ± 11 | 76 ± 11 | 73 ± 10 | 73 ± 11 | 70 ± 11 | 0.008 |
| uACR (mg/mmol) | 0.33 (0.00–1.50) | 0.13 (0.00–0.58) | 0.16 (0.00–0.97) | 0.50 (0.00–2.07) | 1.17 (0.15–4.20) | <0.001 |
| hsCRP (mg/l) | 2.2 (1.1–4.6) | 1.7 (0.8–3.4) | 2.0 (1.1–3.6) | 2.5 (1.3–5.5) | 3.3 (1.7–6.2) | <0.001 |
Data shown are mean ± standard deviation, number (percent), or median (lower quartile–upper quartile).
BMI, body mass index; creat, creatinine; cys, cystatin C; creat-cys, creatinine and cystatin C; CVD, cardiovascular disease; DBP, diastolic blood pressure; eGFR, estimated glomerular filtration rate; hsCRP, high-sensitivity C-reactive protein; SBP, systolic blood pressure; uACR, urine albumin-to-creatinine ratio.