Table 2.
Baseline Characteristics of ATN Study Participants by Uric Acid Tertiles
| Characteristic | All Participants (n = 250) | Tertile 1 (n = 83) | Tertile 2 (n = 83) | Tertile 3 (n = 84) |
|---|---|---|---|---|
| Plasma uric acid,a mg/dL | 11.1 [8.6-14.2] (3.3-29.4) | 3.3-9.4 | 9.5-12.9 | 13.0-29.4 |
| Demographics | ||||
| Female sex | 77 (30.8%) | 31 (37.4%) | 25 (30.1%) | 21 (25.0%) |
| Age, y | 62.0 ± 14.6 | 65.5 ± 13.1 | 60.5 ± 15.7 | 59.9 ± 14.5 |
| White | 199 (79.6%) | 67 (80.7%) | 67 (80.7%) | 65 (77.4%) |
| Premorbid characteristics | ||||
| Scr, mg/dL | 1.1 [0.8-1.4] | 1.0 [0.8-1.3] | 1.1 [0.8-1.4] | 1.1 [0.9-1.4] |
| eGFR, mL/min/1.73 m2 | 69.1 ± 32.8 | 72.1 ± 32.7 | 68.5 ± 33.7 | 66.8 ± 32.3 |
| Weight, kg | 76.4 ± 15.6 | 73.1 ± 17.3 | 76.5 ± 13.4 | 79.5 ± 15.4 |
| Comorbid conditionsb | ||||
| Cardiovascular disease | 82 (32.8%) | 30 (36.1%) | 21 (25.3%) | 31 (36.9%) |
| Diabetes mellitus | 72 (28.8%) | 20 (24.1%) | 23 (27.7%) | 29 (34.5%) |
| Malignancy | 50 (20.0%) | 15 (18.1%) | 17 (20.5%) | 18 (21.4%) |
| Immunocompromised | 35 (14.0%) | 11 (13.3%) | 11 (13.3%) | 13 (15.5%) |
| Cerebrovascular disease | 29 (11.6%) | 8 (9.6%) | 9 (10.8%) | 12 (14.3%) |
| Chronic hypoxemia | 25 (10.0%) | 11 (13.3%) | 4 (4.8%) | 10 (11.9%) |
| Enrollment characteristics | ||||
| BUN before RRT, mg/dL | 69.5 ± 30.1 | 62.8 ± 31.3 | 67.1 ± 26.5 | 78.5 ± 30.3 |
| Scr before RRT, mg/dL | 4.1 [3.0-5.6] | 3.6 [2.7-4.7] | 4.2 [3.1-5.4] | 4.7 [3.7-6.3] |
| MAP, mm Hg | 76.0 ± 15.4 | 74.8 ± 15.3 | 77.7 ± 15.4 | 75.6 ± 15.5 |
| Urine volume, mL/24 h | 195 [72-545] | 155 [70-455] | 255 [107-532] | 210 [62-638] |
| Urine volume, mL/h | 10.9 [4.2-26.0] | 8.1 [4.9-19.6] | 12.2 [5.3-26.3] | 10.6 [2.8-29.2] |
| Oliguria | 189 (75.6%) | 66 (79.5%) | 63 (75.9%) | 60 (71.4%) |
| Mechanical ventilation | 189 (75.6%) | 65 (78.3%) | 62 (74.7%) | 62 (73.8%) |
| APACHE II score | 26 [21-31] | 25 [21-31] | 27 [22-32] | 26 [22-31] |
| SOFA cardiovascular score | ||||
| 0-2 | 102 (40.8%) | 30 (36.1%) | 34 (41.0%) | 38 (45.2%) |
| 3-4 | 148 (59.2%) | 53 (63.9%) | 49 (59.0%) | 46 (54.8%) |
| Treatment | ||||
| Intensive | 122 (48.8%) | 45 (54.2%) | 35 (42.2%) | 42 (50.0%) |
| Less intensive | 128 (51.2%) | 38 (45.8%) | 48 (57.8%) | 42 (50.0%) |
| ICU type | ||||
| Medical | 122 (48.8%) | 36 (43.4%) | 43 (51.8%) | 43 (51.2%) |
| Surgical | 108 (43.2%) | 38 (45.8%) | 35 (42.2%) | 35 (41.7%) |
| Other | 20 (8.0%) | 9 (10.8%) | 5 (6.0%) | 6 (7.1%) |
| Postsurgical | 126 (50.4%) | 47 (56.6%) | 43 (51.8%) | 36 (42.9%) |
| Cause of AKIc | ||||
| Ischemic | 198 (79.2%) | 66 (79.5%) | 66 (79.5%) | 66 (78.6%) |
| Nephrotoxic | 48 (19.2%) | 16 (19.2%) | 15 (18.1%) | 17 (20.2%) |
| Sepsis | 132 (52.8%) | 41 (49.4%) | 49 (59.0%) | 42 (50.0%) |
| Multifactorial | 135 (54.0%) | 39 (47.0%) | 45 (54.2%) | 51 (60.7%) |
Note: Data presented as mean ± standard deviation or median [IQR] for continuous variables and frequencies for binary or categorical variables. eGFR was determined using the Modification of Diet in Renal Disease Study equation. Conversion factors for units: Scr in mg/dL to μmol/L, ×88.4; plasma uric acid in mg/dL to μmol/L, ×59.48; BUN in mg/dL to mmol/L, ×0.357.
Abbreviations: APACHE, Acute Physiology and Chronic Health Evaluation; ATN, Acute Renal Failure Trial Network; AKI, acute kidney injury; BUN, blood urea nitrogen; eGFR, estimated glomerular filtration rate; ICU, intensive care unit; IQR, interquartile range; MAP, mean arterial pressure; RRT, renal replacement therapy; Scr, serum creatinine; SOFA, Sequential Organ Failure Assessment.
Plasma uric acid presented as median [IQR] with range for all participants and range for each tertile.
Cardiovascular disease includes participants with a history of myocardial infarction, angina, or congestive heart failure. Diabetes mellitus includes participants with a history of end-organ disease from diabetes, use of diabetic diet, or use of diabetic medications. Malignancy includes participants with a history of leukemia and tumors with or without metastasis. Immunocompromised includes participants with a history of human immunodeficiency virus infection, AIDS, or on immunosuppressive therapy. Cerebrovascular disease includes participants with a history of transient ischemic attack or stroke.
Participants could have had more than 1 reason for AKI.