Table 1.
Demographics and clinical characteristics by quartiles of klotho
| Variable | Full Cohort | Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 |
| Range (pg/ml) | <478 | 478–630 | 631–816 | >816 | |
| N | 2774 | 694 | 693 | 694 | 693 |
| Age (yrs) | 75±3 | 75±3 | 75±3 | 75±3 | 75±3 |
| Female, n (%) | 1417 (51) | 360 (52) | 326 (47) | 347 (50) | 384 (55) |
| Black race, n (%) | 1103 (40) | 258 (37) | 229 (33) | 268 (39) | 348 (50) |
| Diabetes, n (%) | 1019 (37) | 233 (34) | 269 (39) | 249 (36) | 268 (39) |
| Hypertension, n (%) | 2093 (76) | 516 (74) | 532 (77) | 516 (74) | 529 (76) |
| Smoking, n (%) | |||||
| Former | 1277 (46) | 352 (51) | 328 (47) | 320 (46) | 277 (40) |
| Current | 268 (10) | 67 (10) | 74 (11) | 64 (9) | 63 (9) |
| Antihypertensive medications, n (%) | |||||
| ACE-I | 471 (17) | 128 (19) | 118 (17) | 110 (16) | 115 (17) |
| ARBs | 96 (4) | 26 (4) | 19 (3) | 26 (4) | 25 (4) |
| Beta blockers | 416 (15) | 124 (18) | 115 (17) | 99 (14) | 78 (11) |
| Calcium channel blockers | 658 (24) | 180 (26) | 144 (21) | 154 (22) | 180 (26) |
| Diuretics | 792 (29) | 213 (31) | 194 (28) | 183 (26) | 202 (29) |
| Any HTN medication | 1584 (57) | 411 (59) | 394 (57) | 382 (55) | 397 (57) |
| Coronary artery disease, n (%) | 494 (18) | 122 (18) | 117 (17) | 123 (18) | 132 (20) |
| Heart failure, n (%) | 33 (1) | 6 (1) | 7 (1) | 12 (2) | 8 (1) |
| Cerebrovascular disease, n (%) | 192 (7) | 55 (8) | 42 (6) | 42 (6) | 53 (8) |
| Systolic BP (mmHg) | 134±21 | 132±21 | 134±21 | 134±21 | 135±21 |
| Diastolic BP (mmHg) | 70±12 | 69±12 | 71±12 | 71±12 | 71±12 |
| Body mass index (kg/m2) | 27.2±4.8 | 27.3±4.8 | 27.3±4.4 | 27.1±4.8 | 27.1±5.1 |
| Total cholesterol (mg/dl) | 206±39 | 207±40 | 205±39 | 204±38 | 207±38 |
| C-reactive protein (mg/L) | 2.97 (1.25, 6.44) | 4.04 (1.65, 8.24) | 2.88 (1.31, 6.02) | 2.65 (1.14, 6.13) | 2.38 (1.15, 5.49) |
| eGFR_cysC (ml/min per 1.73 m2) | 72±18 | 70±20 | 71±18 | 73±18 | 76±18 |
| eGFR_cysC <60, n (%) | 677 (25) | 205 (30) | 180 (26) | 167 (24) | 125 (18) |
| Urine albumin-creatinine ratio (mg/g) | 8 (4, 19) | 7 (4, 16) | 7 (4, 20) | 8 (4, 19) | 8 (4, 20) |
| UACR ≥30 mg/g, n (%) | 480 (18) | 107 (16) | 119 (17) | 124 (18) | 130 (19) |
| Vitamin D 25(OH)2 (ng/ml) | 26±11 | 26±12 | 26±11 | 26±11 | 25±12 |
| Calcium (mg/dl) | 8.9±0.4 | 8.9±0.4 | 8.8±0.4 | 8.9±0.4 | 8.9±0.5 |
| Phosphate (mg/dl) | 3.6±0.5 | 3.6±0.5 | 3.5±0.5 | 3.5±0.5 | 3.6±0.5 |
| Parathyroid hormone (pg/ml) | 34 (25, 46) | 34 (25, 47) | 34 (25, 46) | 34 (26, 45) | 32 (25, 46) |
| FGF-23 (pg/ml) | 47 (37, 60) | 49 (38, 64) | 48 (37, 60) | 46 (36, 59) | 45 (36, 58) |
ACE-I, angiotensin-converting enzyme inhibitors; ARB, angiotensin II receptor blocker; HTN, hypertension; UACR, urine albumin-creatinine ratio; FGF-23, fibroblast growth factor 23.