Table 1.
Demographics and MRI measures of the upper arm muscle and nonmuscle CSA and LV systolic function in DMD participants and the healthy volunteers
| DMD (N = 12) Median (IQR) | Healthy volunteer (N = 20) Median (IQR) | Mann–Whitney P value | |
|---|---|---|---|
| Age (years) | 8.0 (2.75) | 10.0 (2.75) | 0.06 |
| Height (cm) | 123.4 (12.6) | 145.2 (12.5) | <0.0001 |
| Weight (kg) | 30.7 (13.6) | 40.3 (13.7) | <0.05 |
| Body mass index (kg/m2) | 20.3 (6.6) | 17.3 (4.6) | 0.06 |
| Body surface area (m2) | 1.0 (0.26) | 1.3 (0.25) | <0.001 |
| Right upper arm CSA (cm2)a | 36.0 (16) | 33.0 (18) | 0.3 |
| Muscle (% of CSA)a | 43.0 (16) | 50.0 (12) | 0.1 |
| Biceps CSA (cm2)a | 4.0 (1.6) | 4.5 (1.9) | 0.2 |
| Triceps CSA (cm2)a | 10.0 (5) | 10.0 (4) | 0.3 |
| Nonmuscle soft tissue (% of CSA)a | 53.0 (17) | 45.0 (10) | <0.05 |
| Bone (% of CSA)a | 3.0 (1.6) | 6.0 (1.6) | <0.0001 |
| Heart rate (beats/min) | 97.0 (15) | 79.0 (21) | <0.001 |
| LV EF (%) | 60.0 (14.2) | 62.3 (7.2) | 0.6 |
| LV EDVi (mL/m2) | 75.4 (14.2) | 75.3 (13.6) | 0.6 |
| LV ESVi (mL/m2) | 30.3 (9.6) | 30.2 (5.8) | 0.9 |
| LV ED mass (g/m2) | 44.4 (10) | 43.8 (16.5) | 0.8 |
| SV index (mL/m2) | 44.0 (9) | 47.5 (10.2) | 0.5 |
| Cardiac index (L/min per m2) | 4.1 (1.1) | 3.8 (1.1) | <0.05 |
MRI, magnetic resonance imaging; LV, left ventricular; DMD, Duchenne muscular dystrophy; IQR, interquartile range; CSA, cross‐sectional area; EF, ejection fraction; EDVi, end‐diastolic volume index; ESVi, end‐systolic volume index; ED, end diastolic; SV, stroke volume.
a
N = 19 healthy volunteers.