Table 3.
Baseline laboratory investigations
| Laboratory parameter | NDD-CKD (n = 470,807) |
DD-CKDa (n = 21,334) |
DD-CKDb (n = 21,334) |
Incident dialysis (n = 6,214) |
||||
|---|---|---|---|---|---|---|---|---|
| n (%) | median (IQR) | n (%) | median (IQR) | n (%) | median (IQR) | n (%) | median (IQR) | |
| Serum creatinine, mg/dL | 470,803 (100.0) | 1.3 (1.1–1.6) | 21,193 (99.3) | 5.3 (3.4–7.8) | 21,334 (100.0) | 4.4 (2.2–7.2) | 6,073 (97.7) | 5.0 (3.5–7.2) |
| Hemoglobin, g/dL | 406,165 (86.3) | 12.5 (11.0–13.9) | 20,918 (98.1) | 9.6 (8.4–11.0) | 20,438 (95.8) | 10.5 (9.2–11.8) | 6,045 (97.3) | 9.1 (8.2–10.4) |
| Serum bicarbonate, mmol/L | 380,807 (80.9) | 26.0 (23.0–28.0) | 19,688 (92.3) | 25.0 (22.0–27.2) | 19,589 (91.8) | 25.0 (22.0–27.5) | 5,658 (91.1) | 24.0 (21.9–27.0) |
| Serum potassium, mmol/L | 386,302 (82.1) | 4.2 (3.9–4.6) | 19,724 (92.5) | 4.3 (3.9–4.7) | 19,634 (92.0) | 4.3 (3.9–4.8) | 5,680 (91.4) | 4.2 (3.8–4.6) |
| Serum albumin, g/dL | 290,393 (61.7) | 3.8 (3.4–4.1) | 17,012 (79.7) | 3.2 (2.6–3.7) | 16,096 (75.5) | 3.4 (2.9–3.8) | 5,020 (80.8) | 3.1 (2.6–3.5) |
| LDL-C, mg/dL | 207,664 (44.1) | 91.0 (70.0–118.0) | 6,967 (32.7) | 78.0 (57.0–107.0) | 6,604 (31.0) | 85.0 (62.0–114.0) | 2,436 (39.2) | 79.7 (57.0–107.2) |
| Cholesterol, mg/dL | 192,705 (40.9) | 168.0 (140.0–199.0) | 8,655 (40.6) | 149.0 (119.0–185.0) | 8,252 (38.7) | 157.0 (126.0–195.0) | 2,794 (45.0) | 151.0 (120.0–187.0) |
| Serum triglyceride, mg/dL | 182,312 (38.7) | 129.0 (93.0–184.0) | 8,074 (37.9) | 124.0 (88.0–183.0) | 7,645 (35.8) | 129.0 (91.0–192.0) | 2,658 (42.8) | 128.0 (89.0–185.0) |
| HDL-C, mg/dL | 174,228 (37.0) | 45.0 (36.5–56.0) | 7,866 (36.9) | 39.0 (30.0–49.0) | 7,402 (34.7) | 39.0 (31.0–50.0) | 2,601 (41.9) | 40.0 (32.0–50.0) |
| HbAlc, % | 169,474 (36.0) | 6.4 (5.8–7.5) | 11,261 (52.8) | 6.2 (5.4–7.4) | 10,114 (47.4) | 6.4 (5.5–7.8) | 3,682 (59.3) | 6.3 (5.5–7.5) |
| Serum phosphate, mg/dL | 109,968 (23.4) | 3.4 (2.9–4.0) | 16,815 (78.8) | 4.4 (3.4–5.6) | 13,760 (64.5) | 4.2 (3.4–5.3) | 5,149 (82.9) | 4.4 (3.4–5.5) |
| Serum ferritin, ng/dL | 46,407 (9.9) | 126.0 (50.0–307.8) | 8,722 (40.9) | 337.0 (148.0–706.0) | 6,328 (29.7) | 310.0 (126.0–682.9) | 3,116 (50.1) | 270.5 (123.0–557.2) |
| Serum iron, μg/dL | 45,212 (9.6) | 55.0 (34.0–80.0) | 9,606 (45.0) | 47.0 (31.0–70.0) | 7,011 (32.9) | 49.0 (32.0–72.0) | 3,360 (54.1) | 48.0 (31.0–70.0) |
| Serum iron binding, μg/dL | 41,606 (8.8) | 295.0 (233.0–361.0) | 7,668 (35.9) | 220.0 (176.0–269.0) | 5,635 (26.4) | 226.0 (180.0–279.0) | 2,648 (42.6) | 232.0 (188.0–281.0) |
| Serum urate, mg/dL | 27,794 (5.9) | 6.7 (5.4–8.2) | 3,260 (15.3) | 6.9 (5.2–8.8) | 2,464 (11.6) | 6.8 (5.1–8.7) | 1,176 (18.9) | 7.5 (5.8–9.0) |
| Serum transferrin, mg/dL | 20,152 (4.3) | 220.0 (174.0–265.0) | 5,592 (26.2) | 165.0 (132.0–200.0) | 3,683 (17.3) | 168.0 (133.0–206.0) | 2,027 (32.6) | 172.0 (141.0–208.0) |
| Serum C-reactive protein, mg/dL | 22,073 (4.7) | 2.0 (0.7–5.2) | 1,748 (8.2) | 2.7 (1.0–5.7) | 1,430 (6.7) | 2.5 (1.0–5.6) | 596 (9.6) | 2.5 (0.8–5.2) |
Baseline investigations within 1 year before the index date. Values recorded within 7 days after the index date are also included. Parathyroid hormones and urine albumin-to-creatinine ratio were not recorded. Among the 492,141 patients in the study cohort, the proportions of missing data for individual parameters were serum creatinine, 0%; hemoglobin, 13.3%; serum bicarbonate, 18.6%; serum potassium, 17.5%; serum albumin, 37.7%; LDL-C, 56.5%; cholesterol, 59.2%; serum triglyceride, 61.4%; HDL-C, 63.1%; HbAlc, 63.5%; serum phosphate, 74.9%; serum ferritin, 89.3%; serum iron, 89.4%; serum iron binding, 90.4%; serum urate, 93.9%; serum transferrin, 95.2%; and serum C-reactive protein, 95.2%. CKD, chronic kidney disease; DD, dialysis-dependent; HbAlc, hemoglobin Alc; HDL-C, high-density lipoprotein cholesterol; IQR, interquartile range; LDL-C, low-density lipoprotein cholesterol; NDD, nondialysis-dependent.
Dialysis date as index date.
CKD diagnosis as index date.