Article Figures & Data
Figures
- Figure 1.
Distribution of the GFR. GFR is expressed in ml/min/1.73 m2 as calculated with the MDRD equation. The red lines separated the different categories of eGFR: 15 ml/min/1.73 m2, 30 ml/min/1.73 m2, 60 ml/min/1.73 m2, and 90 ml/min/1.73 m2. GFR: glomerular filtration rate; eGFR: estimated GFR; MDRD: Modification of Diet in Renal Disease.
- Figure 2.
Forest plot of the variables associated with renal impairment (eGFR < 60 ml/min/m2). Black squares correspond to the OR while the horizontal bars represent the 95% CI. eGFR: estimated glomerular filtration rate; CRP: C-reactive protein; BASDAI: Bath Ankylosing Spondylitis Activity Index; NSAID: nonsteroidal antiinflammatory drug.
Tables
- Table 1.
Comparative analysis of demographic, SpA-related characteristics, CV risk factors, and disease activity variables according to eGFR in patients with SpA. Values are n (%) unless otherwise specified.
Characteristics Total, n = 2098 eGFR ≥ 60 ml/min/1.73 m2, n = 1945 eGFR < 60 ml/min/1.73 m2, n = 153 p Demographic and SpA-related characteristics Age, yrs 45.3 (13.7) 44.6 (13.3) 53.6 (14.6) < 0.001* Age < 45 yrs 1083 (51.6) 1039 (53.4) 44 (28.8) < 0.001* Age 45–59 yrs 697 (33.2) 646 (33.2) 51 (33.3) Age ≥ 60 yrs 318 (15.2) 206 (13.4) 58 (37.9) Male 1332 (63.5) 1244 (64) 88 (57.2) 0.11 SpA duration, yrs, mean (SD) 8.6 (9) 8.6 (8.9) 9.8 (10) 0.70 HLA-B27 positivity 1126 (73.1) 1073 (74) 53 (59.6) 0.003* Axial involvement 1805 (86.1) 1677 (86.3) 267 (13.7) 0.37 Peripheral involvement 1283 (61.2) 1174 (60.4) 109 (71.2) 0.008* Sacroiliitis on radiograph 1315 (62.8) 1220 (62.8) 95 (62.5) 0.23 Sacroiliitis on MRI 558 (26.6) 520 (26.8) 38 (25) 0.75 Extraarticular manifestations 488 (23.3) 454 (23.3) 34 (22.2) 0.75 CV characteristics Hypertension 753 (35.9) 676 (34.8) 77 (50.3) < 0.001* Systolic blood pressure, mmHg, mean (SD) 124.2 (15.7) 123.9 (15.5) 127.6 (16.8) 0.009* Diastolic blood pressure, mmHg, mean (SD) 77.2 (10.2) 77.1 (10.2) 78.4 (10) 0.15 Diabetes 238 (11.3) 210 (10.8) 28 (18.3) 0.005* Current smoker 526 (25.1) 498 (25.6) 28 (18.3) 0.06 Previous smoker 524 (25) 476 (22.7) 48 (31.3) Never smoker 1046 (49.9) 969 (49.9) 77 (50.3) LDL cholesterol, g/l, mean (SD) 1.30 (1) 1.30 (1) 1.2 (0.7) 0.73 HDL cholesterol, g/l, mean (SD) 0.7 (0.9) 0.7 (0.9) 0.7 (0.7) 0.67 BMI, mean (SD) 26.7 (6.0) 26.8 (6.0) 26.6 (5.6) 0.76 Framingham risk score, mean (SD) 8.3 (8.2) 7.9 (7.9) 12.8 (10.2) < 0.001* SpA activity scores BASDAI, mean (SD) 3.6 (2.4) 3.5 (2.4) 4.1 (2.4) 0.001* BASDAI < 4/10 1230 (58.8) 1154 (59.5) 763(49.7) 0.02 BASDAI ≥ 4/10 862 (41.2) 785 (40.5) 77 (50.3) ASDAS-ESR, mean (SD) 2.3 (1.1) 2.3 (1.1) 2.8 (1.1) < 0.001* ASDAS-CRP, mean (SD) 1.9 (1.1) 1.9 (1.1) 2.4 (1.1) < 0.001* PGA, mean (SD) 3.1 (2) 3.1 (2) 3.7 (2.1) < 0.001* ESR, mm in 1st h, median (IQR) 12 (6–24) 12 (5–23) 22 (6–24) < 0.001* CRP, mg/dl, median (IQR) 0.1 (0.03–0.32) 0.1 (0.03–0.3) 0.2 (0.05–1.2) < 0.001* SpA severity variables BASFI, mean (SD) 3.1 (2.7) 2.9 (2.7) 4.4 (2.6) < 0.001* EQ-5D, mean (SD) 0.58 (0.3) 0.59 (0.31) 0.39 (0.31) < 0.001* Hip replacement 81 (4) 71 (3.8) 10 (6.9) 0.16 Bamboo spine 166 (8) 154 (8) 12 (7.8) 0.9 SpA treatment Current DMARD 1641 (78.2) 1523 (78.3) 118 (77.1) 0.73 Anti-TNF 1017 (48.5) 954 (49.1) 63 (41.2) 0.06 MTX 727 (34.7) 672 (34.6) 55 (36.0) 0.73 Current steroids 257 (12.3) 237 (12.2) 20 (13.1) 0.77 Cumulative steroid dose, mg, median (IQR) 2050 (600–7300) 2050 (650–7420) 2120 (365–3916) 0.33 NSAID intake, last 3 mos 1429 (68.3) 1334 (68.8) 95 (62.1) 0.09 ASAS-NSAID score, median (IQR) 12.1 (0–57) 12.6 (0–57) 7.5 (0–50) 0.18 NSAID % days of intake since onset 57.8 51 58.4 0.008* ↵* p < 0.05. SpA: spondyloarthritis; CV: cardiovascular; eGFR: glomerular filtration rate in ml/min/1.73 m2 estimated by the MDRD equation; MDRD: Modification of Diet in Renal Disease; sacroiliitis on radiograph: at least grade 2 bilateral or 3 unilateral; sacroiliitis on MRI: according to the ASAS definition; MRI: magnetic resonance imaging; ASAS: Assessment of Spondyloarthritis international Society; extraarticular manifestations: psoriasis, uveitis, or inflammatory bowel disease; LDL: low-density lipoprotein; HDL: high-density lipoprotein; BMI: body mass index; BASDAI: Bath Ankylosing Spondylitis Activity Index; ASDAS: Ankylosing Spondylitis Disease Activity Score; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; PGA: physician’s global assessment; IQR: interquartile range; BASFI: Bath Ankylosing Spondylitis Functional Index; DMARD: disease-modifying antirheumatic drug; TNF: tumor necrosis factor; MTX: methotrexate; NSAID: nonsteroidal antiinflammatory drugs.
- APPENDIX 1.
Multivariate analysis of the variables associated with renal impairment (eGFR < 60 ml/min/1.73 m2).
Variables OR 95% CI p Age, yrs ≤ 45 yrs Reference 46–59 yrs 2.1 1.1–3.9 0.017* ≥ 60 yrs 7.5 3.2–17.5 < 0.001* HLA-B27 positivity 0.58 0.3–1.1 0.08 ASDAS-CRP < 1.3 Reference 1.3–2.0 1.7 0.9–3.3 0.11 2.1–3.4 2.9 1.6–5.4 < 0.001* ≥ 3.5 4.9 2.2–10.9 < 0.001* Disease duration 0.9 0.9–1.1 0.2 Framingham risk score 1 1 0.12 % days NSAID intake 1 1 0.3 ↵* p < 0.05.
eGFR: estimated glomerular filtration rate; ASDAS: Ankylosing Spondylitis Disease Activity Score; CRP: C-reactive protein; NSAID: nonsteroidal antiinflammatory drug.
