Table 2.
Comparison of baseline characteristics across different hemoglobin trajectory groups.
| Characteristics | All N = 694 | Group 1 N = 181 | Group 2 N = 157 | Group 3 N = 124 | Group 4 N = 122 | Group 5 N = 110 | P |
|---|---|---|---|---|---|---|---|
| Demographics | |||||||
| Male, n (%) | 431 (62.1%) | 89 (49.2%) | 130 (82.8%) | 87 (70.2%) | 64 (52.5%) | 61 (55.5%) | <0.001 |
| Age, years | 64.7 [55.0; 72.8] | 67.0 [57.5; 75.2] | 60.9 [50.3; 68.1] | 64.7 [54.5; 71.0] | 69.6 [58.1; 74.8] | 65.0 [58.5; 75.2] | <0.001 |
| BMI, kg/m2 | 24.0 [21.5; 26.6] | 23.3 [21.4; 25.5] | 24.8 [23.0; 27.3] | 24.7 [22.5; 26.8] | 22.8 [20.8; 26.5] | 23.3 [21.1; 26.5] | 0.001 |
| Systolic blood pressure, mmHg | 134 [123; 148] | 133 [120; 143] | 132 [122; 144] | 138 [128; 153] | 134 [125; 151] | 138 [124; 150] | 0.046 |
| Follow-up duration (days) | 2,057 [1,484; 2,627] | 2,165 [1,528; 2,648] | 2,212 [1,633; 2,660] | 2,058 [1,380; 2,607] | 1,878 [1,402; 2,427] | 1,974 [1,422; 2,587] | 0.006 |
| Comorbidities | |||||||
| Hypertension, n (%) | 605 (87.2%) | 157 (86.7%) | 132 (84.1%) | 109 (87.9%) | 108 (88.5%) | 99 (90.0%) | 0.659 |
| Diabetes, n (%) | 288 (41.5%) | 61 (33.7%) | 48 (30.6%) | 63 (50.8%) | 56 (45.9%) | 60 (54.5%) | <0.001 |
| Laboratory parameters | |||||||
| Hemoglobin, g/L | 12.8 [11.5; 14.1] | 12.2 [11.2; 12.8] | 14.6 [13.8; 15.3] | 13.7 [12.7; 14.6] | 11.2 [9.80; 12.6] | 12.4 [11.1; 13.6] | <0.001 |
| eGFR, ml/min/1.73 m2 | 42.2 [29.6; 52.3] | 38.4 [27.0; 49.8] | 50.1 [44.1; 54.3] | 40.2 [30.1; 50.6] | 35.4 [24.8; 50.3] | 37.5 [26.5; 49.5] | <0.001 |
| Albumin, g/L | 4.00 [3.70; 4.20] | 4.00 [3.80; 4.30] | 4.20 [4.00; 4.40] | 3.90 [3.70; 4.20] | 3.80 [3.40; 4.10] | 3.80 [3.30; 4.10] | <0.001 |
| Total protein, g/L | 7.00 [6.60; 7.30] | 7.00 [6.70; 7.30] | 7.10 [6.80; 7.40] | 6.95 [6.50; 7.30] | 6.80 [6.40; 7.20] | 6.80 [6.30; 7.20] | <0.001 |
| Uric acid, mg/dl | 6.40 [5.47; 7.40] | 6.30 [5.50; 7.20] | 6.50 [5.50; 7.40] | 6.40 [5.60; 7.40] | 6.20 [5.20; 7.40] | 6.60 [5.70; 7.90] | 0.128 |
| Sodium, mmol/L | 141 [139; 142] | 141 [140; 143] | 141 [140; 143] | 141 [139; 142] | 141 [139; 142] | 141 [139; 142] | 0.007 |
| Potassium, mmol/L | 4.40 [4.10; 4.80] | 4.50 [4.30; 4.8 0] | 4.30 [4.00; 4.60] | 4.50 [4.18; 4.80] | 4.50 [4.10; 4.80] | 4.50 [4.10; 4.90] | 0.009 |
| C-reactive protein, mg/L | 0.09 [0.05; 0.21] | 0.08 [0.05; 0.17] | 0.09 [0.05; 0.19] | 0.10 [0.05; 0.36] | 0.11 [0.05; 0.36] | 0.11 [0.05; 0.23] | 0.071 |
| Blood urea nitrogen, mmol/L | 20.8 [16.0; 27.9] | 21.9 [17.2; 31.0] | 17.6 [14.2; 22.1] | 21.2 [16.9; 27.5] | 22.9 [17.4; 31.3] | 22.8 [16.1; 29.3] | <0.001 |
| 24 h urine protein, mg | 695 [240; 1,568] | 488 [89.0; 1,176] | 572 [228; 1,100] | 1,235 [288; 2,183] | 972 [282; 1,822] | 1,076 [445; 2,004] | 0.093 |
| Medication use | |||||||
| ESA use, n (%) | 60 (8.65%) | 9 (4.97%) | 4 (2.55%) | 8 (6.45%) | 16 (13.1%) | 23 (20.9%) | <0.001 |
| Iron supplementation, n (%) | 37 (5.33%) | 6 (3.31%) | 1 (0.64%) | 7 (5.6%) | 10 (8.20%) | 13 (11.8%) | 0.001 |
Data are presented as median [interquartile range] for continuous variables and n (%) for categorical variables.
P-values were calculated using Kruskal–Wallis test for continuous variables and chi-square test or Fisher's exact test for categorical variables.
To convert hemoglobin from g/dl to g/L, multiply by 10. To convert BUN from mg/dl to mmol/L, multiply by 0.357.
To convert creatinine from mg/dl to μmol/L, multiply by 88.4. To convert uric acid from mg/dl to μmol/L, multiply by 59.48.
BMI, body mass index; eGFR, estimated glomerular filtration rate; ESA, erythropoiesis-stimulating agent; BUN, blood urea nitrogen.
Group definitions: Group 1 (Low-Stable): persistently low hemoglobin with minimal fluctuation; Group 2 (High-Stable): persistently high hemoglobin with minimal fluctuation; Group 3 (Rapid-Declining): moderate baseline with steepest decline; Group 4 (Lowest-Plateau): lowest baseline with early rapid rise then plateaus; Group 5 (Low-Declining): low baseline with early decline then persistently low.