Table 1.
Baseline demographic and clinical characteristics of the study population by the presence of preceding AKIOPT.
| Variables | No AKIOPT | AKIOPT | AKIOPT status | p-value | ||
|---|---|---|---|---|---|---|
| Stable AKIOPT | Deteriorating AKIOPT | No AKIOPT VS AKIOPT | No AKIOPT VS AKIOPT status | |||
| Participant, n | 4141 | 1905 | 1537 | 368 | ─ | ─ |
| Proportion of the study population (%) | 68.5 | 31.5 | 25.4 | 6.1 | ─ | ─ |
| Proportion of patients with AKIOPT (%) | ─ | ─ | 80.7 | 19.3 | ─ | ─ |
| Age at entry (year) | 66.7 (56.4, 76.0) | 68.9 (58.7, 77.3) | 69.6 (59.2, 78.1) | 65.5 (56.3, 74.8) | <0.001 | <0.001 |
| Body mass index | 24.4 (22.1, 27.2) | 23.8 (21.3, 26.8) | 23.9 (21.3, 26.8) | 23.4 (21.1, 27.0) | <0.001 | <0.001 |
| Time from the lowest eGFR to pre-ESRD enrollment (month) | 0.10 (0.00, 1.74) | 0.43 (0.00, 1.67) | 0.52 (0.00, 1.84) | 0.00 (0.00, 0.62) | <0.001 | <0.001 |
| Serum creatinine variability (mg/dL) – 180 days prior to pre-ESRD enrollment | ||||||
| Minimum | 1.76 (1.27, 3.10) | 1.80 (1.21, 3.04) | 1.69 (1.18, 2.66) | 2.87 (1.64, 4.60) | 0.241 | <0.001 |
| Maximum | 2.08 (1.49, 3.70) | 3.64 (2.40, 6.30) | 3.41 (2.30, 5.47) | 5.89 (3.18, 8.85) | <0.001 | <0.001 |
| Difference1 | 0.30 (0.16, 0.60) | 1.63 (0.98, 3.00) | 1.51 (0.93, 2.66) | 2.57 (1.31, 4.20) | <0.001 | <0.001 |
| Percent change (%)2 | 17.2 (9.8, 27.0) | 77.1 (54.9, 122.0) | 77.8 (55.2, 121.8) | 76.3 (53.7, 122.0) | <0.001 | <0.001 |
| eGFR variability (ml/min/1.73m2) – 180 days prior to pre-ESRD enrollment | ||||||
| Minimum | 29.1 (14.2, 45.0) | 13.7 (7.6, 23.8) | 15.1 (8.7, 25.1) | 8.1 (5.2, 16.4) | <0.001 | <0.001 |
| Maximum | 35.7 (17.6, 54.4) | 32.5 (18.0, 54.1) | 35.6 (21.0, 56.8) | 19.3 (11.0, 37.9) | 0.685 | <0.001 |
| Difference3 | 5.0 (2.4, 9.2) | 16.1 (8.6, 28.4) | 18.2 (10.2, 30.1) | 10.1 (5.4, 21.0) | <0.001 | <0.001 |
| Percent change (%)4 | 17.0 (10.0, 24.8) | 49.6 (40.9, 61.5) | 49.6 (40.9, 61.5) | 49.6 (40.4, 61.6) | <0.001 | <0.001 |
| Woman, n (%) | 1710 (41.29) | 887 (46.56) | 714 (46.45) | 173 (47.01) | <0.001 | 0.001 |
| Smoking, n (%) | 0.046 | 0.024 | ||||
| Never | 3435 (82.95) | 1610 (84.51) | 1300 (84.58) | 310 (84.24) | ||
| Former | 303 (7.32) | 147 (7.72) | 126 (8.20) | 21 (5.71) | ||
| Current | 403 (9.73) | 148 (7.77) | 111 (7.22) | 37 (10.05) | ||
| Alcohol consumption, n (%) | 0.008 | 0.008 | ||||
| Never | 3787 (91.45) | 1747 (91.71) | 1403 (91.28) | 344 (93.48) | ||
| Former | 214 (5.17) | 118 (6.19) | 103 (6.70) | 15 (4.08) | ||
| Current | 140 (3.38) | 40 (2.10) | 31 (2.02) | 9 (2.45) | ||
| Education, n (%) | <0.001 | <0.001 | ||||
| <9 yrs | 1066 (25.74) | 615 (32.28) | 499 (32.47) | 116 (31.52) | ||
| 9 ≤ ~<12 yrs | 1595 (38.52) | 758 (39.79) | 608 (39.56) | 150 (40.76) | ||
| 12 ≤ ~<16 yrs | 968 (23.38) | 394 (20.68) | 315 (20.49) | 79 (21.47) | ||
| 16 + yrs | 512 (12.36) | 138 (7.24) | 115 (7.48) | 23 (6.25) | ||
| Primary etiologies of CKD, n (%) | <0.001 | <0.001 | ||||
| CGN | 1557 (37.70) | 584 (30.69) | 479 (31.18) | 105 (28.61) | ||
| Systemic disease | 2278 (55.16) | 1176 (61.80) | 943 (61.39) | 233 (63.49) | ||
| Obstructive nephropathy | 95 (2.30) | 77 (4.05) | 64 (4.17) | 13 (3.54) | ||
| Other nephropathy | 200 (4.84) | 66 (3.47) | 50 (3.26) | 16 (4.36) | ||
| CKD stage at enrollment, n (%) | <0.001 | <0.001 | ||||
| 1 | 173 (4.18) | 18 (0.94) | 18 (1.17) | 0 (0.00) | ||
| 2 | 315 (7.61) | 55 (2.89) | 53 (3.45) | 2 (0.54) | ||
| 3 | 1779 (42.96) | 572 (30.03) | 521 (33.90) | 51 (13.86) | ||
| 4 | 949 (22.92) | 625 (32.81) | 545 (35.46) | 80 (21.74) | ||
| 5 | 925 (22.34) | 635 (33.33) | 400 (26.02) | 235 (63.86) | ||
| Diabetes, n (%) | 1608 (38.84) | 1019 (53.52) | 833 (54.23) | 186 (50.54) | <0.001 | <0.001 |
| Hypertension, n (%) | 2482 (59.95) | 1294 (67.96) | 1043 (67.90) | 251 (68.21) | <0.001 | <0.001 |
| Cardiovascular disease, n (%) | 1595 (38.53) | 922 (48.48) | 771 (50.26) | 151 (41.03) | <0.001 | <0.001 |
| Medication utilization 90 days prior to AKIOPT, n (%) | ||||||
| NSAIDs | 476 (11.51) | 392 (20.60) | 342 (22.28) | 50 (13.59) | <0.001 | <0.001 |
| Contrast | 217 (5.25) | 309 (16.24) | 263 (17.13) | 46 (12.50) | <0.001 | <0.001 |
| ACEI | 623 (15.06) | 329 (17.29) | 269 (17.52) | 60 (16.30) | 0.028 | 0.075 |
| ARBs | 1538 (37.19) | 676 (35.52) | 543 (35.37) | 133 (36.14) | 0.213 | 0.443 |
| Diuretics | 1415 (34.21) | 1062 (55.81) | 830 (54.07) | 232 (63.04) | <0.001 | <0.001 |
| Medication utilization one year prior to pre-ESRD enrollment, n (%) | ||||||
| Pentoxifylline | 990 (23.94) | 434 (22.81) | 357 (23.26) | 77 (20.92) | 0.337 | 0.402 |
| NSAIDs | 1053 (25.46) | 728 (38.26) | 620 (40.39) | 108 (29.35) | <0.001 | <0.001 |
| Contrast | 588 (14.22) | 618 (32.48) | 518 (33.75) | 100 (27.17) | <0.001 | <0.001 |
| Anti-platelet | ||||||
| Aspirin | 1193 (28.84) | 684 (35.94) | 570 (37.13) | 114 (30.98) | <0.001 | <0.001 |
| Dipyridamole | 304 (7.35) | 132 (6.94) | 106 (6.91) | 26 (7.07) | 0.564 | 0.842 |
| other Anti-platelet agents | 392 (9.48) | 333 (17.50) | 280 (18.24) | 53 (14.40) | <0.001 | <0.001 |
| Urate-lowering/gout related medications | ||||||
| Allopurinol | 516 (12.48) | 241 (12.66) | 189 (12.31) | 52 (14.13) | 0.837 | 0.626 |
| Febuxostat | 68 (1.64) | 74 (3.89) | 56 (3.65) | 18 (4.89) | <0.001 | <0.001 |
| Benzbromarone | 508 (12.28) | 199 (10.46) | 169 (11.01) | 30 (8.15) | 0.040 | 0.038 |
| Colchicine | 504 (12.19) | 294 (15.45) | 234 (15.24) | 60 (16.30) | 0.001 | 0.002 |
| Sulfinpyrazone | 50 (1.21) | 24 (1.26) | 22 (1.43) | 2 (0.54) | 0.864 | 0.373 |
| Anti-hypertensive agents | ||||||
| ACEI | 970 (23.45) | 586 (30.79) | 482 (31.40) | 104 (28.26) | <0.001 | <0.001 |
| ARBs | 1896 (45.84) | 932 (48.98) | 756 (49.25) | 176 (47.83) | 0.023 | 0.068 |
| Diuretics | 1875 (45.33) | 1374 (72.20) | 1096 (71.40) | 278 (75.54) | <0.001 | <0.001 |
| Anti-diabetic agents | ||||||
| Oral hypoglycemic agents | 1332 (32.21) | 781 (41.04) | 640 (41.69) | 141 (38.32) | <0.001 | <0.001 |
| Insulin | 796 (19.25) | 858 (45.09) | 710 (46.25) | 148 (40.22) | <0.001 | <0.001 |
| Baseline biochemical parameters | ||||||
| eGFR (mL/min/1.73m2) | 30.8 (15.1, 47.6) | 20.1 (10.7, 33.1) | 22.9 (13.1, 36.0) | 9.5 (5.6, 18.5) | <0.001 | <0.001 |
| Serum creatinine (mg/dL) | 1.90 (1.37, 3.47) | 2.62 (1.69, 4.53) | 2.40 (1.61, 3.92) | 4.43 (2.45, 7.71) | <0.001 | <0.001 |
| Blood urea nitrogen (mg/dL) | 30.0 (19.0, 49.0) | 40.0 (25.0, 63.0) | 38.0 (24.0, 58.0) | 59.0 (35.0, 85.0) | <0.001 | <0.001 |
| Serum uric acid (mg/dL) | 7.30 (6.10, 8.60) | 7.70 (6.40, 9.30) | 7.60 (6.30, 9.30) | 7.90 (6.60, 9.30) | <0.001 | <0.001 |
| Calcium (mg/dL) | 8.90 (8.40, 9.20) | 8.70 (8.20, 9.10) | 8.70 (8.30, 9.10) | 8.65 (8.10, 9.05) | <0.001 | <0.001 |
| Phosphate (mg/dL) | 4.10 (3.60, 4.80) | 4.30 (3.60, 5.20) | 4.20 (3.60, 5.00) | 4.70 (4.00, 6.00) | <0.001 | <0.001 |
| Serum albumin (g/dL) | 3.90 (3.40, 4.20) | 3.60 (3.10, 4.00) | 3.60 (3.10, 4.00) | 3.50 (3.00, 4.00) | <0.001 | <0.001 |
| Hemoglobin (g/dL) | 11.2 (9.5, 13.1) | 10.2 (9.0, 11.8) | 10.3 (9.2, 11.9) | 9.7 (8.5, 11.0) | <0.001 | <0.001 |
| Urine PCR (mg/g) | 781 (201, 2442) | 1293 (290, 3916) | 1080 (251, 3483) | 1970 (741, 5911) | <0.001 | <0.001 |
1Difference of serum creatinine = maximum serum creatinine -minimum serum creatinine.
2Percent change of serum creatinine = (maximum serum creatinine -minimum serum creatinine)/minimum serum creatinine × 100%.
3Difference of eGFR = maximum eGFR -minimum eGFR.
4Percent change of eGFR = (maximum eGFR -minimum eGFR)/maximum eGFR × 100%.
p-values are calculated by Wilcoxon rank sum test for continuous variables and Chi-square test for categorical variables.
Abbreviations: ACEI: angiotensin-converting enzyme inhibitor, AKI: acute kidney injury, ARB: angiotensin II receptor blocker, CGN: chronic glomerulonephritis, CKD: chronic kidney disease, eGFR: estimated glomerular filtration rate, IQR: inter-quartile range, NSAID: non-steroidal anti-inflammatory drug, PCR: protein to creatinine ratio.