Table 3.
Baseline demographic and clinical characteristics stratified by quartiles of urine non-albumin proteinuria (uNAP) defined by subtracting uACR from uPCR ratio.
| Variable | Total (n = 2904) | uNAP ≦ 80.3 (n = 725) | 80.3 < uNAP ≦ 186.3 (n = 727) | 186.3 < uNAP ≦ 682.9 (n = 726) | uNAP > 682.9 (n = 726) | P-value† | P for trend‡ |
|---|---|---|---|---|---|---|---|
| Age (year), median (IQR) | 58.6 (45.4, 70.8) | 49.9 (36.6, 60.8) | 59.1 (47.4, 71.9) | 62.7 (51.7, 74.3) | 62.2 (49.6, 73.8) | < 0.001 | < 0.001 |
| Female, n (%) | 1207 (41.6) | 269 (37.1) | 310 (42.6) | 288 (39.7) | 340 (46.8) | 0.001 | 0.001 |
| Body mass index (kg/m2), median (IQR) | 24.1 (21.8, 27.3) | 24.3 (21.4, 27.1) | 24.4 (22.1, 27.2) | 24.0 (21.8, 27.3) | 24.1 (21.8, 27.4) | 0.8 | 0.7 |
| Follow-up duration (year), median (IQR) | 3.32 (1.41, 6.28) | 3.39 (1.79, 6.21) | 4.19 (2.06, 7.15) | 3.30 (1.25, 6.08) | 2.45 (0.88, 5.13) | < 0.001 | < 0.001 |
| Baseline comorbidities, n (%) | |||||||
| CKD stage 1–2 | 1343 (47.3) | 539 (78.1) | 431 (60.8) | 250 (34.9) | 123 (17.0) | < 0.001 | < 0.001 |
| CKD stage 3–5 | 1495 (52.7) | 151 (21.9) | 278 (39.2) | 466 (65.1) | 600 (83.0) | ||
| Diabetes | 928 (32.1) | 120 (16.7) | 215 (29.7) | 262 (36.2) | 331 (45.6) | < 0.001 | < 0.001 |
| Hypertension | 1245 (43.0) | 181 (25.1) | 282 (38.9) | 364 (50.4) | 418 (57.6) | < 0.001 | < 0.001 |
| Cardiovascular disease | 766 (26.5) | 107 (14.9) | 173 (23.9) | 218 (30.2) | 268 (37.0) | < 0.001 | < 0.001 |
| Cancer before enrollment | 265 (9.1) | 40 (5.5) | 70 (9.6) | 87 (12.0) | 68 (9.4) | < 0.001 | 0.004 |
| Cancer after enrollment | 166 (5.7) | 21 (2.9) | 50 (6.9) | 48 (6.6) | 47 (6.5) | 0.002 | 0.007 |
| Cancer (before or after enrollment) | 431 (14.8) | 61 (8.4) | 120 (16.5) | 135 (18.6) | 115 (15.8) | < 0.001 | < 0.001 |
| Baseline medication profiles, n (%) | |||||||
| Pentoxifylline | 389 (14.8) | 41 (7.1) | 72 (11.1) | 139 (20.0) | 137 (19.5) | < 0.001 | < 0.001 |
| Dipyridamole | 91 (3.5) | 9 (1.6) | 14 (2.2) | 33 (4.8) | 35 (5.0) | 0.001 | < 0.001 |
| Anti-platelet agents | 683 (26.0) | 104 (18.0) | 160 (24.6) | 213 (30.7) | 206 (29.3) | < 0.001 | < 0.001 |
| NSAIDs | 721 (27.5) | 154 (26.7) | 176 (27.0) | 205 (29.5) | 186 (26.4) | 0.5 | 0.9 |
| Contrast | 479 (18.2) | 88 (15.3) | 107 (16.4) | 152 (21.9) | 132 (18.8) | 0.01 | 0.02 |
| Antihypertension agents | |||||||
| ACEI | 465 (17.7) | 50 (8.7) | 100 (15.4) | 123 (17.7) | 192 (27.3) | < 0.001 | < 0.001 |
| ARBs | 919 (35.0) | 146 (25.3) | 208 (32.0) | 265 (38.2) | 300 (42.6) | < 0.001 | < 0.001 |
| Diuretics | 1192 (45.4) | 141 (24.4) | 220 (33.8) | 327 (47.1) | 504 (71.6) | < 0.001 | < 0.001 |
| Antidiabetic agents | |||||||
| OAD | 724 (27.6) | 105 (18.2) | 190 (29.2) | 195 (28.1) | 234 (33.2) | < 0.001 | < 0.001 |
| Insulin | 539 (20.5) | 33 (5.7) | 85 (13.1) | 178 (25.7) | 243 (34.5) | < 0.001 | < 0.001 |
| Baseline biochemical profiles, median (IQR) | |||||||
| eGFR (mL/min/1.73m2) | 56.8 (27.8, 91.8) | 89.3 (63.1, 107.0) | 70.0 (47.3, 96.7) | 44.4 (24.7, 75.6) | 19.6 (8.4, 45.6) | < 0.001 | < 0.001 |
| Serum creatinine (mg/dL) | 1.23 (0.86, 2.16) | 0.92 (0.76, 1.18) | 1.04 (0.79, 1.42) | 1.48 (1.00, 2.44) | 2.84 (1.45, 5.75) | < 0.001 | < 0.001 |
| Blood urea nitrogen (mg/dL) | 20.0 (13.0, 36.0) | 13.0 (10.0, 17.0) | 17.0 (12.0, 22.0) | 23.0 (15.0, 37.0) | 42.0 (23.0, 68.0) | < 0.001 | < 0.001 |
| Serum uric acid (mg/dL) | 6.50 (5.20, 8.00) | 5.90 (4.80, 7.10) | 6.10 (5.00, 7.40) | 7.00 (5.50, 8.50) | 7.30 (6.00, 8.90) | < 0.001 | < 0.001 |
| Sodium (mmol/L) | 138 (136, 140) | 138 (137, 140) | 138 (136, 140) | 137 (135, 139) | 137 (135, 140) | < 0.001 | < 0.001 |
| Potassium (mmol/L) | 4.10 (3.70, 4.50) | 4.00 (3.80, 4.30) | 4.00 (3.80, 4.40) | 4.10 (3.70, 4.50) | 4.20 (3.70, 4.60) | 0.02 | 0.002 |
| Calcium (mg/dL) | 8.70 (8.20, 9.20) | 9.10 (8.80, 9.40) | 9.00 (8.60, 9.30) | 8.90 (8.40, 9.20) | 8.30 (7.80, 8.80) | < 0.001 | < 0.001 |
| Phosphate (mg/dL) | 4.00 (3.40, 4.80) | 3.60 (3.20, 4.10) | 3.70 (3.10, 4.20) | 3.90 (3.30, 4.50) | 4.50 (3.70, 5.60) | < 0.001 | < 0.001 |
| Serum albumin (g/dL) | 4.00 (3.30, 4.40) | 4.40 (4.10, 4.60) | 4.20 (3.90, 4.50) | 3.90 (3.50, 4.30) | 3.20 (2.60, 3.70) | < 0.001 | < 0.001 |
| Hemoglobin (g/dL) | 11.9 (9.8, 13.8) | 13.6 (12.1, 14.8) | 13.2 (11.7, 14.5) | 11.6 (10.0, 13.2) | 9.9 (8.6, 11.7) | < 0.001 | < 0.001 |
| Total cholesterol (mg/dL) | 181 (152, 214) | 184 (159, 213) | 179 (155, 210) | 180 (149, 208) | 182 (149, 229) | 0.07 | 0.8 |
| Triglyceride (mg/dL) | 129 (85, 195) | 119 (79, 178) | 125 (82, 182) | 130 (92, 197) | 142 (93, 221) | < 0.001 | < 0.001 |
| Glucose (mg/dL) | 116 (99, 159) | 106 (96, 131) | 114 (99, 154) | 122 (100, 163) | 127 (101, 178) | < 0.001 | < 0.001 |
| Urine creatinine (mg/dL) | 92.3 (59.4, 144.0) | 142.1 (104.1, 189.4) | 98.7 (68.6, 147.7) | 80.7 (56.1, 121.3) | 62.5 (45.6, 90.3) | < 0.001 | < 0.001 |
| uPCR (mg/g) | 310 (101, 1,608) | 69 (55, 85) | 153 (118, 216) | 634 (396, 1,110) | 3828 (2231, 6827) | < 0.001 | < 0.001 |
| uACR (mg/g) | 86 (13, 757) | 7 (4, 19) | 30 (11, 89) | 254 (77, 674) | 2167 (853, 4219) | < 0.001 | < 0.001 |
| uAPR (%) | 30.0 (10.8, 57.5) | 11.4 (6.3, 25.4) | 21.3 (8.6, 42.5) | 44.4 (20.0, 64.4) | 57.3 (37.4, 66.9) | < 0.001 | < 0.001 |
| uNAP (mg/g) | 186 (80, 683) | 58 (47, 68) | 112 (94, 140) | 340 (246, 483) | 1575 (1019, 2670) | < 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.