Table 1.
Characteristics of the study population by quartiles of plasma fibroblast growth factor 23
| Fibroblast Growth Factor 23 (RU/ml) | |||||
|---|---|---|---|---|---|
| Characteristic mean ± SD or n (%) |
Quartile 1 1.8–93.8 N=376 |
Quartile 2 93.9–134.4 N=376 |
Quartile 3 134.5–209.6 N=374 |
Quartile 4 209.7–5354.8 N=375 |
p* |
| Demographics | |||||
| Age (years) | 54 ± 12 | 57 ± 12 | 59 ± 11 | 57 ± 11 | <0.01 |
| Female sex | 145 (38.6) | 167 (44.4) | 169 (45.2) | 208 (55.5) | <0.01 |
| Race | 0.01 | ||||
| White | 192 (51.0) | 176 (46.8) | 180 (48.1) | 155 (41.3) | |
| Black | 119 (31.7) | 123 (32.7) | 99 (26.5) | 136 (36.3) | |
| Other | 65 (17.3) | 77 (20.5) | 95 (25.4) | 84 (22.4) | |
| Hispanic ethnicity | 55 (14.6) | 67 (17.8) | 96 (25.7) | 105 (28.0) | <0.01 |
| Traditional CV Risk Factors | |||||
| Prior CVD | 50 (13.3) | 75 (20.0) | 90 (24.1) | 133 (35.5) | <0.01 |
| Diabetes | 112 (29.8) | 157 (41.8) | 208 (55.6) | 230 (61.3) | <0.01 |
| Former/current smoker | 170 (45.2) | 188 (50.0) | 180 (48.1) | 202 (53.9) | 0.12 |
| Body mass index (kg/m2) | <0.01 | ||||
| <25 | 81 (21.6) | 77 (20.5) | 53 (14.2) | 49 (13.1) | |
| 25–29.9 | 122 (32.5) | 125 (33.2) | 128 (34.2) | 83 (22.1) | |
| 30–39.9 | 151 (40.3) | 145 (38.6) | 154 (41.2) | 180 (48.0) | |
| ≥40 | 21 (5.6) | 29 (7.7) | 39 (10.4) | 63 (16.8) | |
| Hypertension | 270 (71.8) | 313 (83.2) | 337 (90.1) | 349 (93.1) | <0.01 |
| Hypercholesterolemia | 248 (66.0) | 275 (73.1) | 311 (83.4) | 307 (81.9) | <0.01 |
| Kidney Function | |||||
| Estimated GFR (ml/min/1.73m2) | 60.3 ± 17.1 | 50.8 ± 15.6 | 41.6 ± 11.7 | 34.8 ± 13.0 | <0.01 |
| CKD stage | <0.01 | ||||
| 2 (eGFR ≥ 60 ml/min/1.73m2) | 181 (48.1) | 95 (25.3) | 20 (5.4) | 9 (2.4) | |
| 3a (eGFR 45–59 ml/min/1.73m2) | 124 (33.0) | 136 (36.3) | 121 (32.4) | 64 (17.1) | |
| 3b (eGFR 30–44 ml/min/1.73m2) | 65 (17.3) | 114 (30.4) | 170 (45.5) | 153 (40.8) | |
| 4/5 (eGFR <30 ml/min/1.73m2) | 6 (1.6) | 30 (8.0) | 63 (16.8) | 149 (39.7) | |
| Urinary ACR (mg/g)† | 15 (5, 140) | 31 (6, 341) | 101 (11, 782) | 224 (29, 1632) | <0.01 |
| <30 | 215 (59.4) | 173 (48.7) | 145 (40.2) | 89 (25.0) | <0.01 |
| 30–299 | 78 (21.6) | 88 (24.8) | 77 (21.3) | 100 (28.1) | |
| 300–999 | 45 (12.4) | 47 (13.2) | 65 (18.0) | 49 (13.8) | |
| ≥1000 | 24 (6.6) | 47 (13.2) | 74 (20.5) | 118 (33.2) | |
| Mineral Metabolism Parameters | |||||
| Corrected serum calcium (mg/dl) | 9.18 ± 0.40 | 9.18 ± 0.44 | 9.27 ± 0.48 | 9.32 ± 0.48 | <0.01 |
| Serum phosphate (mg/dl) | 3.39 ± 0.53 | 3.63 ± 0.56 | 3.81 ± 0.62 | 4.08 ± 0.81 | <0.01 |
| Parathyroid hormone (pg/ml)† | 41 (29, 61) | 49 (32, 74) | 54 (38, 87) | 77 (45, 135) | <0.01 |
| Parathyroid hormone >65 pg/ml | 78 (21.1) | 116 (31.4) | 147 (39.7) | 219 (59.2) | <0.01 |
| Use of active vitamin D | 5 (1.3) | 4 (1.1) | 13 (3.5) | 15 (4.0) | 0.02 |
| Use of phosphate binders | 5 (1.3) | 7 (1.9) | 14 (3.8) | 19 (5.1) | <0.01 |
*
p-value by anova or kruskal-wallis test (continuous variables) and Chi-squared (categorical variables)
†
presented as median (IQR)
CVD, cardiovascular disease; GFR, glomerular filtration rate; CKD, chronic kidney disease; ACR, albumin to creatinine ratio