Table 1. Baseline clinical characteristics of patients.
| CRP category | |||||
|---|---|---|---|---|---|
| Characteristic | Total (n = 345) | Group1a (n = 101) | Group2b (n = 100) | Group3c (n = 144) | P value |
| Age, years | 57.2 (12.8) | 53.0 (12.1) | 57.9 (13.7) | 58.9d(12.4) | 0.009 |
| Female, n (%) | 294 (85) | 90 (89) | 84 (84) | 120 (83) | 0.42 |
| Serum creatinine, mg/dL | 0.59 (0.10) | 0.61 (0.09) | 0.60 (0.11) | 0.58 (0.11) | 0.10 |
| eGFR, mL/min per 1.73m2 | 86.9 (16.8) | 84.6 (12.7) | 86.1 (18.9) | 89.2 (17.6) | 0.09 |
| Baseline CRP, mg/L | 4.7 (1.4,16.4) | 0.7 (0.4,1.6) | 3.7d (1.9,7.9) | 16.3d,e (8.0,28.7) | <0.0001 |
| 3 months CRP, mg/L | 3.8 (1.2,12.3) | 0.7 (0.4,1.3) | 3.0d (1.5,5.5) | 13.1d,e (6.8,24.2) | <0.0001 |
| 6 months CRP, mg/L | 3.5 (1.1,11.6) | 0.7 (0.4,1.3) | 2.4d (1.4,4.7) | 12.2d,e (6.5,24.9) | <0.0001 |
| Comorbid conditions | |||||
| Hypertension, n (%) | 149 (43) | 32 (32) | 37 (37) | 80 (56) d,e | 0.0003 |
| Diabetes mellitus, n (%) | 33 (10) | 6 (6) | 10 (10) | 17 (12) | 0.30 |
| Dyslipidemia, n (%) | 100 (29) | 28 (27) | 25 (25) | 47 (33) | 0.41 |
| Overweight, n (%) | 95 (28) | 22 (22) | 25 (25) | 48 (33) | 0.11 |
| Smoking, n (%) | 37 (11) | 9 (9) | 9 (9) | 19 (13) | 0.46 |
| Systolic blood pressure, mmHg | 127 (17) | 123 (17) | 127 (18) | 130 (16) d | 0.008 |
| Diastolic blood pressure, mmHg | 76 (11) | 74 (11) | 75 (11) | 78 (11) d | 0.03 |
| Fasting blood glucose, mg/dl | 94 (18) | 91 (12) | 94 (21) | 96 (19) d | 0.06 |
| Total cholesterol, mg/dL | 195 (32) | 198 (30) | 194 (34) | 195 (31) | 0.70 |
| Low-density lipoprotein cholesterol, mg/dL | 112 (28) | 112 (26) | 110 (33) | 114 (25) | 0.43 |
| High-density lipoprotein cholesterol, mg/dL | 61 (17) | 63 (14) | 61 (17) | 61 (18) | 0.59 |
| Triglyceride, mg/dL | 93 (71,123) | 93 (69,123) | 93 (72,123) | 94 (72,123) | 0.79 |
| Body mass index, kg/ m2 | 23.3 (3.7) | 22.8 (3.2) | 22.9 (3.3) | 23.9 (4.2) | 0.04 |
| Renin-angiotensin system inhibitor, n (%) | 32 (9) | 7 (7) | 5 (5) | 20 (14) d | 0.04 |
| Statin, n (%) | 26 (8) | 7 (7) | 9 (9) | 10 (7) | 0.81 |
| RA-related | |||||
| Disease duration of RA, years | 6 (3,11) | 5 (3,9) | 7 (2,11) | 6 (3,13) d | 0.09 |
| Rheumatoid factor positive, n (%) | 284 (82) | 69 (68) | 85 (85) d | 130 (90) d | <0.0001 |
| MTX, n (%) | 187 (54) | 40 (40) | 58 (58) d | 89 (62) d | 0.002 |
| Other DMARDs | 233 (68) | 60 (59) | 68 (68) | 105 (73) | 0.08 |
| Nephrotoxic DMARDs | 177 (51) | 49 (49) | 54 (54) | 74 (51) | 0.74 |
| Biological agent, n (%) | 31 (9) | 6 (6) | 8 (8) | 17 (12) | 0.26 |
| Corticosteroids, n (%) | 192 (56) | 33 (33) | 61 (61) d | 98 (68) d | <0.0001 |
| NSAIDs, n (%) | 158 (46) | 31 (31) | 50 (50) d | 77 (53) d | 0.001 |
Abbreviations: CRP, C-reactive protein; eGFR, estimated glomerular filtration rate;
RA, rheumatoid arthritis; MTX, methotrexate; DMARDs, disease modifying anti-rheumatic drugs; NSAIDs, nonsteroidal anti-inflammatory drugs.
Data are expressed as mean ±standard deviation, medians (25th, 75th), or number (%).
Group 1 a was defined as all three CRP values were ≤3.0 mg/L.
Group 2 b was defined as one or two CRP values were >3.0 mg/L.
Group 3 c was defined as all three CRP values were >3.0 mg/L.
d p < 0.05 vs group1.
e p < 0.05 vs group2.