Table 4.
Comparisons of disease characteristics among rheumatoid arthritis patients in body composition subgroups
| Characteristics | Normal fat and non‐myopenia (n = 167) | Overfat but non‐myopenia (n = 84) | Normal fat but myopenia (n = 142) | Overfat and myopenia (n = 64) | P a |
|---|---|---|---|---|---|
| Female, n (%) | 136 (81.4) | 70 (83.3) | 117 (82.4) | 55 (85.9) | 0.876 |
| Age, years, median (IQR) | 48 (40–56) | 53 (46–61) b | 50 (35–61) | 55 (49–62) b | <0.001 |
| Disease duration, month, median (IQR) | 40 (18–84) | 60 (29–120) | 60 (24–108) | 96 (24–153) b | 0.002 |
| BMI, kg/m2, mean ± SD | 21.7 ± 2.1 | 26.6 ± 2.2 b | 18.7 ± 1.7 b , c | 22.4 ± 2.4 c , d | <0.001 |
| Smoking habits | 0.588 | ||||
| Active smoking, n (%) | 25 (15.0) | 13 (15.5) | 21 (14.8) | 9 (14.1) | |
| Exposure to second hand smoke, n (%) | 56 (33.5) | 30 (35.7) | 36 (25.4) | 17 (26.6) | |
| Without exposure to smoke, n (%) | 86 (51.5) | 41 (48.8) | 85 (59.9) | 38 (59.4) | |
| Positive RF, n (%) | 108 (64.7) | 50 (59.5) | 95 (66.9) | 47 (73.4) | 0.349 |
| Positive ACPA, n (%) | 121 (72.5) | 58 (69.0) | 91 (64.1) | 47 (73.4) | 0.374 |
| Core disease activity indicators | |||||
| Morning stiffness, min, median (IQR) | 0 (0–10) | 0 (0–10) | 0 (0–10) | 0 (0–30) | 0.626 |
| 28TJC, median (IQR) | 1 (0–4) | 2 (0–5) | 2 (0–7) | 4 (1–10) b | 0.012 |
| 28SJC, median (IQR) | 1 (0–4) | 1 (0–3) | 1 (0–4) | 2 (0–8) b | 0.024 |
| PtGA, median (IQR) | 2 (0–5) | 3 (1–5) | 3 (1–6) | 5 (2–7) b , c | 0.001 |
| PrGA, median (IQR) | 2 (0–4) | 2 (1–5) | 3 (1–5) | 5 (2–7) b , c | <0.001 |
| Pain VAS, median (IQR) | 2 (1–4) | 2 (1–4) | 2 (2–4) | 4 (2–6) b , c | 0.001 |
| ESR, (mm/h), median (IQR) | 25 (15–38) | 24 (12–40) | 28 (14–52) | 45 (24–75) b , c , d | <0.001 |
| CRP, (mg/L), median (IQR) | 3.3 (3.3–10.8) | 4.0 (3.3–7.3) | 4.8 (3.3–19.1) | 13.1 (3.4–42.4) b , c , d | <0.001 |
| DAS28‐CRP, median (IQR) | 2.9 (1.9–3.9) | 3.1 (2.0–4.2) | 3.3 (2.1–4.3) | 3.9 (2.7–5.5) b , c | <0.001 |
| DAS28‐CRP ≥ 2.6, n (%) | 99 (59.3) | 50 (59.5) | 94 (66.2) | 52 (81.2) b , c | 0.012 |
| SDAI, median (IQR) | 8.3 (3.3–16.7) | 10.5 (4.3–20.7) | 11.3 (4.3–20.6) | 18.7 (6.1–33.9) b , c | <0.001 |
| CDAI, median (IQR) | 8.0 (2.0–16.0) | 9.5 (2.5–19.8) | 10 (4–20) | 16 (4–33) b , c | 0.001 |
| Functional indicators | |||||
| HAQ‐DI, median (IQR) | 0 (0–0.38) | 0.19 (0–0.72) | 0.25 (0–0.88) b | 0.75 (0.12–1.47) b , c , d | <0.001 |
| Functional limitation, n (%) | 12 (7.2) | 7 (8.3) | 26 (18.3) b | 25 (39.1) b , c , d | <0.001 |
| Radiographic assessment | |||||
| mTSS, median (IQR) | 7.5 (2.5–25.0) | 10.3 (4.6–26.8) | 20.3 (7.4–51.0) b | 26.5 (11.9–114.9) b , c , d | <0.001 |
| JSN subscore, median (IQR) | 1.0 (0–7.5) | 1.5 (0–6.5) | 6.0 (0.5–22.0) b , c | 12.8 (1.6–46.4) b , c | <0.001 |
| JE subscore, median (IQR) | 5.5 (2.0–15.5) | 7.5 (4.1–18.0) | 13.0 (4.0–27.3) b | 19.8 (10.0–65.3) b , c , d | <0.001 |
| Bony erosion, n (%) | 152 (91.0) | 81 (96.4) | 130 (91.5) | 63 (98.4) | 0.110 |
| RJD, n (%) | 73 (43.7) | 42 (50.0) | 95 (66.9) b | 53 (82.8) b , c | <0.001 |
Overfat, BF% ≥ 25% for men and ≥ 35% for women; Myopenia, ASMI≤7.0 kg/m2 in men and ≤ 5.7 kg/m2 in women; Functional limitation, HAQ‐DI > 1; Bony erosion, JE subscore>0; RJD, radiographic joint damage (mTSS>10); IQR, interquartile range.
a
Comparison in four groups by Kruskal–Wallis test.
b
Compared with Normal fat + Non‐myopenia patients in Bonferroni correction, P < 0.0083.
c
Compared with Overfat + Non‐myopenia patients in Bonferroni correction, P < 0.0083.
d
Compared with Normal fat + Myopenia patients in Bonferroni correction, P < 0.0083.