Characteristic | Patients | Controls, n = 59 | ||
---|---|---|---|---|
Active, n = 30 | Inactive, n = 29 | Total, n = 59 | ||
General | ||||
Female | 21 (70) | 15 (52) | 36 (61) | 36 (61) |
Age, yrs | 24.8 (13.7) | 25.7 (11.4) | 25.2 (12.5) | 25.3 (12.5) |
Height, cm | 162 (17) | 170 (12) | 165 (15) | 168 (16) |
Weight, kg | 59.2 (22.9) | 66.1 (22.9) | 62.6 (20.1) | 64.9 (19.9) |
BMI, kg/m2 | 21.8 (5.1) | 22.7 (4.5) | 22.3 (4.8) | 22.5 (4.5) |
Daily smokers | 5/22 (23) | 6/26 (23) | 11/48 (23) | 8/48 (17) |
Exercise ≥ 2–3 h/week | 16/24 (67) | 16/27 (59) | 32/51 (63) | 38/51 (75) |
Exercise ≥ 2–3×/week | 4/24 (17) | 4/27 (15) | 8/51 (16) | 19/51 (37)* |
SF-36 PCS, 0–100↓ | 47.3 (39.1–54.7) | 56.9 (52.3–59.7)*** | 53.9 (46.4–58.2)a | 56.9 (52.8–59.7)*,a |
Disease-specific variables | ||||
Disease duration, yrs | 17.0 (10.6) | 16.7 (10.7) | 16.9 (10.6) | NA |
DAS total, 0–20↑ | 6 (5–8) | 3 (1–4.5)*** | 5 (3–6) | NA |
MyoAct, 0–70↑ | 2.6 (1.3–4.2) | 0.5 (0.0–1.2)*** | 1.2 (0.2–2.8) | NA |
MITAX, 0–63↑ | 4 (3–6) | 1 (0–3) | 3 (0–4) | NA |
MDI, 0–40↑ | 5 (3–7) | 2 (1–5) | 3 (2–6) | NA |
CHAQ/HAQ, 0–3↑ | 0.2 (0.0–0.4) | 0.0 (0.0–0.0)** | 0.00 | NA |
Calcinosis | 12 (40) | 10 (35) | 22 (37) | NA |
Muscle | ||||
MMT-8, 0–80↓ | 75 (73–77) | 79 (79–80)*** | 78 (75–80) | 80 (80–80)*** |
CMAS, 0–52↓ | 47(43–50) | 52 (50–52)*** | 50 (47–52) | 52 (51–52)*** |
MRI pathology | 15 (50) | 6/28 (21) | 21/58 (36.2) | NA |
Lung | ||||
Asthma | 2 (7) | 2 (7) | 4 (7) | 3 (5) |
FVC, % | 93.5 (11.8) | 97.7 (12.8) | 95.6 (12.4) | 102.0 (11.6)** |
TLC, % | 90.7 (9.9)e | 93.8 (11.0)b | 92.3 (10.5)f | 97.4 (11.1)*,f |
DLCOc, % | 78.1 (13.7) | 85.5 (15.0) | 81.7 (14.7) | 93.4 (16.4)*** |
HRCT pathology | 13 (44.8)g | 8 (28.6)b | 21 (36.8)d | NA |
Heart | ||||
Long axis strain, % | 16.7 (0.27) | 16.4 (0.24) | 16.6 (0.25) | 17.7 (0.20)** |
E/É | 8.63 (2.38) | 7.37 (2.00)*,b | 8.02 (2.27)c | 7.11 (1.20)**,d |
ECG pathology | 3 (10) | 7 (24) | 10 (17) | 4 (7) |
↵* p < 0.05.
↵** p < 0.01.
↵*** p < 0.001 between patient/controls and active/inactive disease.
↵a n = 51.
↵b n = 28.
↵c n = 58.
↵d n = 57.
↵e n = 27.
↵f n = 55.
↵g n = 28. BMI: body mass index; SF-36 PCS: Medical Outcomes Study Short Form-36 physical component summary; DAS: Disease Activity Score; MyoAct: Myositis Disease Activity Assessment Visual Analogue scales; MITAX: Myositis Intention to Treat Activity Index; MDI: myositis damage index; CHAQ/HAQ: child/adult Health Assessment Questionnaire; MMT-8: unilateral manual muscle test; CMAS: Childhood Myositis Assessment Score; MRI: magnetic resonance imaging; FVC: forced vital capacity; TLC: total lung capacity; DLCOc: DLCO corrected for hemoglobin; HRCT: high-resolution computed tomography; E/É: early diastolic transmitral flow/early diastolic tissue velocity; ECG: electrocardiography; active/inactive disease: defined according to the PRINTO criteria; ↓: lower score denotes more activity/impairment/disability/damage; ↑: higher score denotes more activity/impairment/disability/damage; NA: not applicable; PRINTO: Pediatric Rheumatology International Trials Organization.