Table 1.
Baseline characteristics according to iron groups
| Iron replete N=1014 (27.1%) |
Iron deficiency N=414 (11.1%) |
Mixed iron deficiency N=236 (6.3%) |
Functional iron deficiency N=286 (7.6%) |
High Iron N=345 (9.2%) |
Non-Classified N=1452 (38.8%) |
|
|---|---|---|---|---|---|---|
| Age, years | 58.6 ± 10.7 | 56.3 ± 12.1 | 58.6 ± 10.2 | 58.4 ± 10.3 | 58.0 ± 10.7 | 57.1 ± 11.1 |
| Female, % | 44.8 | 66.2 | 53.4 | 45.5 | 27.8 | 42.2 |
| Black, % | 41.0 | 41.1 | 52.5 | 58.4 | 43.8 | 38.1 |
| Hispanic, % | 12.2 | 15.0 | 12.3 | 12.9 | 10.4 | 13.4 |
| Current smoking, % | 13.6 | 15.2 | 11.4 | 15.0 | 13.9 | 11.9 |
| BMI, kg/m2 | 32.3 ± 7.4 | 33.7 ± 9.5 | 33.9 ± 10.5 | 33.8 ± 8.4 | 30.5 ± 6.1 | 31.2 ± 7.0 |
| Systolic BP, mmHg | 128.6 ± 21.9 | 130.0 ± 23.5 | 133.1 ± 22.1 | 130.4 ± 22.5 | 127.1 ± 22.4 | 127.3 ± 21.8 |
| Hypertension, % | 88.7 | 87.7 | 85.6 | 90.6 | 85.8 | 83.5 |
| Diabetes, % | 50.5 | 51.9 | 54.2 | 59.4 | 42.0 | 45.1 |
| Heart failure, % | 9.4 | 11.8 | 9.8 | 10.5 | 10.1 | 8.3 |
| Stroke, % | 11.0 | 10.9 | 9.8 | 11.2 | 9.9 | 8.3 |
| CVD, % | 34.1 | 36.5 | 34.3 | 37.4 | 32.2 | 30.4 |
| Oral iron use, % | 34.8 | 40.1 | 34.3 | 31.8 | 33.6 | 38.1 |
| ESA, % | 2.9 | 3.9 | 2.1 | 6.7 | 6.1 | 3.8 |
| Hemoglobin, g/dL | 12.7 ± 1.7 | 11.7 ± 1.6 | 12.2 ± 1.8 | 11.8 ± 1.7 | 12.9 ± 1.9 | 12.9 ± 1.7 |
| Iron, ug/dL | 85.8 ± 25.6 | 53.9 ± 17.8 | 58.7 ± 17.6 | 57.4 ± 21.7 | 132.2 ± 44.2 | 104.3 ± 37.8 |
| TIBC, ug/L | 3871.9 ± 1096.1 | 4366.8 ± 1178.8 | 4101.9 ± 1024.8 | 3975.3 ± 1329.5 | 3754.6 ± 1158.3 | 3898.5 ± 1163.5 |
| TSAT, % | 22.3 ± 3.0 | 12.6 ± 3.2 | 14.3 ± 2.2 | 14.4 ± 2.5 | 35.7 ± 8.2 | 27.2 ± 7.5 |
| Ferritin, ng/mL | 159.8 (119.9, 209.3) |
42.7 (27.3, 62.3) |
116.1 (98.7, 137.2) |
248.7 (195.5, 355.0) |
449.0 (354.6, 654.7) |
158.3 (67.4, 330.5) |
| CRP, mg/L | 2.4 (1.1 – 5.6) |
3.8 (1.3 – 8.9) |
3.9 (1.6 – 8.9) |
6.8 (2.5 – 16.0) |
2.0 (0.9 – 4.3) |
2.0 (0.9 – 5.0) |
| eGFR, ml/min/1.73m2 | 43.6 ± 15.0 | 44.2 ± 15.7 | 43.4 ± 15.2 | 40.1 ± 13.3 | 43.2 ± 14.5 | 46.0 ± 14.9 |
| UACR, ug/mg | 58.3 (8.9, 445.1) |
66.8 (11.2, 441.5) |
68.3 (11.6, 454.1) |
82.3 (14.7, 568.3) |
45.6 (8.0, 610.2) |
40.0 (7.1, 442.3) |
| Serum albumin, g/dL | 4.0 ± 0.5 | 3.8 ± 0.4 | 3.9 ± 0.5 | 3.9 ± 0.5 | 4.0 ± 0.6 | 4.0 ± 0.5 |
| Phosphate, mg/dL | 3.7 ± 0.7 | 3.8 ± 0.7 | 3.8 ± 0.6 | 3.8 ± 0.6 | 3.7 ± 0.7 | 3.7 ± 0.7 |
| FGF23, RU/ml | 142.3 (98.4, 225.5) |
238.1 (149.2, 439.5) |
179.9 (110.8, 264.6) |
166.0 (108.5, 277.7) |
130.6 (87.1, 192.9) |
129.0 (87.6, 205.7) |
| PTH, pg/ml | 54.0 (35.0, 90.0) |
60.0 (35.1, 95.0) |
59.3 (36.3, 114.9) |
62.0 (41.4, 106.4) |
53.0 (35.4, 86.3) |
50.8 (33.3, 83.0) |
Results are reported as means ± standard deviations, medians with interquartile ranges or percentiles.
Abbreviations: N, number; BMI, body mass index; BP, blood pressure; CVD, cardiovascular disease; ESA, erythropoietin stimulating agents; TSAT, transferrin saturation; CRP, C-reactive protein; eGFR, estimated glomerular filtration rate; UACR, urine albumin-to-creatinine ratio; FGF23, fibroblast growth factor 23; PTH, parathyroid hormone