Table 1.
Characteristics of the study population (n=94)a
| General characteristics | |
|---|---|
| Gender (males) |
48 (51%) |
| Age at first study visit (years) |
51.1 (38.3-60.6) |
| Age at onset of symptoms (years) |
32.0 (25.5-40.0) |
| • < 18 years |
10 (11%) |
| • ≥ 18 years |
84 (89%) |
| Age at diagnosis (years) |
40.2 (32.7-50.2) |
| Disease duration since onset of first symptoms at first study visit (years) |
15.3 (7.7-24.7) |
| Time since diagnosis at first study visit (years) |
9.2 (0.6-16.0) |
| • 0 to 5 years |
41 (44%) |
| • 5 to 10 years |
15 (16%) |
| • 10 to 15 years |
10 (11%) |
| • > 15 years |
28 (30%) |
| Use of walking aids |
14 (15%) |
| Wheelchair use |
30 (32%) |
| Age at start of wheelchair use (years) |
49.0 (43–56) |
| Use of mechanical ventilation b |
27 (29%) |
| Age at start of mechanical ventilation (years) |
48 (38.5-57.5) |
|
First symptoms notedc | |
| Skeletal muscle weakness |
93 (99%) |
| • Difficulty running |
30 (32%) |
| • Difficulty performing sports |
22 (23%) |
| • Difficulty climbing stairs |
24 (26%) |
| • Difficulty walking |
15 (16%) |
| • Difficulty rising from an armchair |
11 (12%) |
| • Difficulty rising from a lying position |
9 (10%) |
| Fatigue |
17 (18%) |
| Muscle soreness / cramps |
16 (17%) |
| Respiratory failure |
1 (1%) |
|
Clinical features | |
| Ptosis |
22 (23%) |
| Bulbar muscle weakness d |
26 (28%) |
| Scapular winging d |
31 (33%) |
| Scoliosis |
22 (23%) |
| Increased lumbar lordosis |
62 (66%) |
| Prominent muscle atrophy |
53 (56%) |
| • Shoulder girdle / upper arms |
25 (27%) |
| • Trunk muscles |
27 (29%) |
| • Pelvic girdle / Upper leg (Figure
1a) |
40 (43%) |
|
Laboratory parameters | |
| CK (U/l) |
|
| • Males |
449 (279–1040) |
| • Females |
493 (237–715) |
| α-glucosidase activity in leukocytes (nmol glucose/h/mg protein) e |
1.2 (0.4-2.2) |
| α-glucosidase activity in fibroblasts (nmol 4-MU/h/mg protein) f |
13.0 (11.0-15.0) |
| Genotype |
|
| • c.-32-13T>G / very severe or potentially less severe pathogenic mutation |
92 (98%) |
| • c.671G>A / c.525del |
1 (1%) |
| • unknown | 1(1%) |
4-MU: 4-methylumbelliferyl-α-D-glucopyranoside.
a Data are number (%) or median (IQR). b More men then women used mechanical ventilation (p=0.009). c Two or more complaints were counted if these occurred within the same year. d More men than women had scapular winging and bulbar muscle weakness (p=0.001 and p=0.05). e control range 48 to 215 nmol glucose/h/mg protein. f control range 45 to 180 nmol 4-MU/h/mg protein.