Table 3.
Demographic, clinical, and laboratory characteristics of RA patients with and without renal dysfunction based on absolute eGFR values
| Total (n = 1908) | With renal dysfunctiona (n = 645) | Without renal dysfunctiona (n = 1263) | p valueb | |
|---|---|---|---|---|
| Age, years, mean (SD) | 63.3 (13.0) | 72.0 (9.6) | 58.8 (12.3) | < 0.001 |
| ≥ 65 years, patient number (%) | 946 (49.6) | 513 (79.5) | 433 (34.3) | < 0.001 |
| Male/female | 350/1558 | 74/571 | 276/987 | < 0.001 |
| RA duration, years, mean (SD) | 10.8 (9.5) | 12.0 (10.7) | 10.1 (8.8) | < 0.001 |
| ≤ 3 years, patient number (%) | 400 (21.0) | 114 (17.7) | 286 (22.6) | 0.012 |
| Anti-CCP (+), patient number (%) | 1486 (77.9) | 503 (78.0) | 983 (77.8) | 0.95 |
| Stage III/IV, patient number (%) | 911 (47.7) | 340 (52.7) | 571 (45.2) | 0.002 |
| CDAI, mean (SD) | 6.2 (6.7) | 6.3 (6.4) | 6.2 (6.8) | 0.91 |
| HAQ, mean (SD) | 0.42 (0.65) | 0.56 (0.77) | 0.35 (0.56) | < 0.001 |
| ≥ 1.0, patient number (%) | 331 (17.3) | 156 (24.2) | 175 (13.9) | < 0.001 |
| < 0.25, patient number (%) | 671 (35.2) | 278 (43.1) | 393 (31.1) | < 0.001 |
| Serum CRP, mg/dl, mean (SD) | 0.36 (0.93) | 0.42 (1.13) | 0.33 (0.80) | 0.050 |
| BMI, kg/m2, mean (SD) | 22.5 (3.7) | 22.1 (3.2) | 22.8 (3.9) | < 0.001 |
| > 25, patient number (%) | 407 (21.3) | 107 (16.6) | 300 (23.8) | < 0.001 |
| < 18.5, patient number (%) | 196 (10.3) | 70 (10.9) | 126 (10.0) | 0.58 |
| Hypertension, patient number (%) | 624 (32.7) | 316 (49.0) | 308 (24.4) | < 0.001 |
| NIDDM, patient number (%) | 194 (10.2) | 82 (12.7) | 112 (8.9) | 0.010 |
| Serum LDL-C, mg/dl, mean (SD) | 111.4 (28.8) | 110.7 (29.7) | 111.8 (28.4) | 0.45 |
| ≥ 140 mg/dl, patient number (%) | 274 (14.4) | 103 (16.0) | 171 (13.5) | 0.17 |
| Current/ex-smokers, number (%) | 402 (21.1) | 96 (14.9) | 306 (24.2) | < 0.001 |
| Use of biologics, patient number (%) | 641 (33.6) | 239 (37.1) | 402 (31.8) | 0.024 |
| MTX use, patient number (%) | 985 (51.6) | 281 (43.6) | 704 (55.7) | < 0.001 |
| Dose, mg/week, mean (SD) | 7.9 (3.5) | 6.2 (3.0) | 8.2 (3.5) | < 0.001 |
| Cumulative dose, g, median (IQR) | 2.8 (1.2–4.7) | 2.8 (1.2–4.4) | 2.7 (1.2–4.8) | 0.19 |
| NSAID use, patient number (%) | 488 (25.6) | 156 (24.2) | 332 (26.3) | 0.35 |
| ASAS-NSAID score, mean (SD) | 48.5 (21.0) | 49.4 (20.0) | 48.1 (21.5) | 0.52 |
| Concurrent steroids, number (%) | 237 (12.4) | 81 (12.6) | 156 (12.4) | 0.88 |
| Steroid use, patient number (%) | 585 (30.7) | 199 (30.9) | 386 (30.6) | 0.92 |
| Dose, mg/day, mean (SD) | 3.0 (2.1) | 2.9 (1.8) | 3.0 (2.2) | 0.49 |
| Cumulative dose, g, median (IQR) | 3.5 (0.9–10.9) | 5.0 (1.5–14.6) | 3.1 (0.7–9.3) | < 0.001 |
RA rheumatoid arthritis, eGFR estimated glomerular filtration rate, anti-CCP anti-citrullinated peptide antibodies, CDAI clinical disease activity index, HAQ health assessment questionnaire, CRP C-reactive protein, BMI body mass index, NIDDM non-insulin-dependent diabetes mellitus, LDL-C low-density lipoprotein cholesterol, MTX methotrexate, NSAIDs nonsteroidal anti-inflammatory drugs, ASAS Assessment of Spondyloarthritis International Society, SD standard deviation, IQR interquartile range
aDefined as an absolute eGFR < 60 ml/min. Average values of two measurements of eGFR taken over a 3-month interval were used
bComparison between RA patients with renal dysfunction and those without this complication