Table 2.
Baseline demographic and clinical characteristics stratified by quartiles of urine albumin-to-protein ratio (uAPR).
| Variable | Total (n = 2904) | uAPR ≦ 10.8 (n = 723) | 10.8 < uAPR ≦ 30.0 (n = 737) | 30.0 < uAPR ≦ 57.5 (n = 720) | uAPR > 57.5 (n = 724) | P-value† | P for trend‡ |
|---|---|---|---|---|---|---|---|
| Age (year), median (IQR) | 58.6 (45.4, 70.8) | 53.7 (40.2, 66.3) | 59.8 (46.8, 72.5) | 61.9 (49.7, 73.8) | 58.1 (45.5, 69.7) | < 0.001 | < 0.001 |
| Female, n (%) | 1207 (41.6) | 275 (38.0) | 318 (43.2) | 302 (41.9) | 312 (43.1) | 0.2 | 0.09 |
| Body mass index (kg/m2), median (IQR) | 24.1 (21.8, 27.3) | 23.5 (21.3, 25.8) | 23.9 (21.3, 26.7) | 24.0 (21.8, 27.4) | 24.8 (22.5, 28.3) | < 0.001 | < 0.001 |
| Follow-up duration (year), median (IQR) | 3.32 (1.41, 6.28) | 3.33 (1.44, 5.73) | 3.47 (1.45, 6.65) | 3.17 (1.27, 6.46) | 3.25 (1.54, 6.01) | 0.6 | 0.9 |
| Baseline comorbidities, n (%) | |||||||
| CKD stage 1–2 | 1343 (47.3) | 485 (69.8) | 367 (51.4) | 256 (36.0) | 235 (32.7) | < 0.001 | < 0.001 |
| CKD stage 3–5 | 1495 (52.7) | 210 (30.2) | 347 (48.6) | 455 (64.0) | 483 (67.3) | ||
| Diabetes | 928 (32.1) | 144 (19.9) | 226 (30.9) | 269 (37.4) | 289 (40.1) | < 0.001 | < 0.001 |
| Hypertension | 1245 (43.0) | 167 (23.1) | 306 (41.9) | 373 (51.8) | 399 (55.3) | < 0.001 | < 0.001 |
| Cardiovascular disease | 766 (26.5) | 132 (18.3) | 198 (27.1) | 221 (30.8) | 215 (29.8) | < 0.001 | < 0.001 |
| Cancer before enrollment | 265 (9.1) | 61 (8.4) | 80 (10.9) | 64 (8.9) | 60 (8.3) | 0.3 | 0.6 |
| Cancer after enrollment | 166 (5.7) | 39 (5.4) | 48 (6.5) | 50 (6.9) | 29 (4.0) | 0.07 | 0.3 |
| Cancer (before or after enrollment) | 431 (14.8) | 100 (13.8) | 128 (17.4) | 114 (15.8) | 89 (12.3) | 0.04 | 0.3 |
| Baseline medication profiles, n (%) | |||||||
| Pentoxifylline | 389 (14.8) | 40 (6.6) | 72 (10.7) | 120 (17.9) | 157 (23.3) | < 0.001 | < 0.001 |
| Dipyridamole | 91 (3.5) | 13 (2.1) | 21 (3.1) | 28 (4.2) | 29 (4.3) | 0.1 | 0.02 |
| Anti-platelet agents | 683 (26.0) | 129 (21.2) | 171 (25.3) | 196 (29.3) | 187 (27.8) | 0.006 | 0.003 |
| NSAIDs | 721 (27.5) | 190 (31.2) | 212 (31.4) | 176 (26.3) | 143 (21.3) | < 0.001 | < 0.001 |
| Contrast | 479 (18.2) | 142 (23.3) | 146 (21.6) | 108 (16.1) | 83 (12.3) | < 0.001 | < 0.001 |
| Antihypertension agents | |||||||
| ACEI | 465 (17.7) | 50 (8.2) | 107 (15.9) | 160 (23.9) | 148 (22.0) | < 0.001 | < 0.001 |
| ARBs | 919 (35.0) | 108 (17.7) | 217 (32.2) | 267 (39.9) | 327 (48.6) | < 0.001 | < 0.001 |
| Diuretics | 1192 (45.4) | 217 (35.6) | 289 (42.8) | 326 (48.7) | 360 (53.5) | < 0.001 | < 0.001 |
| Antidiabetic agents | |||||||
| OAD | 724 (27.6) | 116 (19.1) | 174 (25.8) | 204 (30.5) | 230 (34.2) | < 0.001 | < 0.001 |
| Insulin | 539 (20.5) | 81 (13.3) | 131 (19.4) | 169 (25.3) | 158 (23.5) | < 0.001 | < 0.001 |
| Baseline biochemical profiles, median (IQR) | |||||||
| eGFR (mL/min/1.73m2) | 56.8 (27.8, 91.8) | 84.0 (53.0, 104.6) | 62.0 (31.9, 94.0) | 46.4 (19.7, 76.3) | 40.9 (19.5, 71.7) | < 0.001 | < 0.001 |
| Serum creatinine (mg/dL) | 1.23 (0.86, 2.16) | 0.96 (0.77, 1.33) | 1.16 (0.81, 1.88) | 1.45 (1.00, 2.87) | 1.59 (1.03, 2.91) | < 0.001 | < 0.001 |
| Blood urea nitrogen (mg/dL) | 20.0 (13.0, 36.0) | 15.0 (11.0, 21.0) | 18.0 (12.0, 31.5) | 24.0 (15.0, 44.0) | 26.0 (16.0, 45.0) | < 0.001 | < 0.001 |
| Serum uric acid (mg/dL) | 6.50 (5.20, 8.00) | 5.80 (4.80, 7.10) | 6.25 (4.90, 7.80) | 6.60 (5.50, 8.00) | 7.20 (6.00, 8.60) | < 0.001 | < 0.001 |
| Sodium (mmol/L) | 138 (136, 140) | 138 (135, 140) | 138 (136, 140) | 138 (135, 140) | 138 (136, 139) | 0.7 | 0.3 |
| Potassium (mmol/L) | 4.10 (3.70, 4.50) | 4.00 (3.70, 4.30) | 4.00 (3.70, 4.40) | 4.10 (3.70, 4.50) | 4.30 (3.80, 4.60) | < 0.001 | < 0.001 |
| Calcium (mg/dL) | 8.70 (8.20, 9.20) | 8.90 (8.30, 9.30) | 8.80 (8.23, 9.20) | 8.70 (8.20, 9.20) | 8.70 (8.10, 9.10) | 0.007 | 0.001 |
| Phosphate (mg/dL) | 4.00 (3.40, 4.80) | 3.70 (3.05, 4.50) | 3.70 (3.20, 4.50) | 4.10 (3.60, 4.90) | 4.30 (3.70, 5.10) | < 0.001 | < 0.001 |
| Serum albumin (g/dL) | 4.00 (3.30, 4.40) | 4.10 (3.50, 4.50) | 4.10 (3.60, 4.40) | 3.90 (3.20, 4.30) | 3.70 (3.10, 4.10) | < 0.001 | < 0.001 |
| Hemoglobin (g/dL) | 11.9 (9.8, 13.8) | 12.5 (10.6, 14.1) | 12.0 (10.1, 13.8) | 10.9 (9.3, 13.3) | 11.9 (9.8, 13.9) | < 0.001 | < 0.001 |
| Total cholesterol (mg/dL) | 181 (152, 214) | 176 (146, 210) | 170 (144, 201) | 179 (153, 207) | 197 (165, 238) | < 0.001 | < 0.001 |
| Triglyceride (mg/dL) | 129 (85, 195) | 113 (74, 173) | 124 (82, 178) | 127 (85, 184) | 152 (103, 231) | < 0.001 | < 0.001 |
| Glucose (mg/dL) | 116 (99, 159) | 112 (97, 154) | 116 (99, 157) | 119 (100, 168) | 119 (98, 160) | 0.05 | 0.05 |
| Urine creatinine (mg/dL) | 92.3 (59.4, 144.0) | 121.3 (74.3, 169.8) | 98.2 (63.3, 151.4) | 83.8 (54.4, 127.6) | 78.0 (53.0, 115.9) | < 0.001 | < 0.001 |
| uPCR (mg/g) | 310 (101, 1,608) | 89 (62, 162) | 138 (87, 380) | 458 (185, 1,733) | 2416 (1,008, 5072) | < 0.001 | < 0.001 |
| uACR (mg/g) | 86 (13, 757) | 5 (3, 10) | 28 (15, 76) | 203 (83, 832) | 1682 (697, 3474) | < 0.001 | < 0.001 |
| uAPR (%) | 30.0 (10.8, 57.5) | 6.0 (4.0, 8.2) | 18.3 (14.4, 23.8) | 45.7 (37.7, 52.6) | 67.8 (62.9, 74.7) | < 0.001 | < 0.001 |
| uNAP (mg/g) | 186 (80, 683) | 83 (58, 156) | 112 (69, 304) | 249 (105, 931) | 674 (280, 1556) | < 0.001 | < 0.001 |
ACEI angiotensin-converting-enzyme inhibitors, ARBs angiotensin receptor blockers, CKD chronic kidney disease, eGFR estimated glomerular filtration rate, NSAIDs nonsteroidal anti-inflammatory drugs, OAD oral antidiabetic agents, uPCR urine protein-to-creatinine ratio, uACR urine albumin-to-creatinine ratio, uAPR urine albumin-to-protein ratio, uNAP urine non-albumin proteinuria.
†P-values are calculated by Kruskal–Wallis test for continuous variables and Chi-square test for categorical variables.
‡P-values for trend are calculated by Spearman's correlation for continuous variables and by Cochran-Armitage trend test for binary variables.