Table 2.
Fibre type distribution, fibre area, fibre perimeter, CAF and CAFA for type I and type IIa fibres.
| Healthy subjects (n = 12) | Mild COPD (n = 8) |
Moderate COPD (n = 9) |
Severe COPD (n = 6) |
P-value | |
|---|---|---|---|---|---|
| Proportion type I fibres (%) | 78.3 ± 8.7 | 70.2 ± 11.4 | 74.5 ± 11.9 | 59.4 ± 9.5* | 0.009 |
| Proportion type IIa fibres (%) | 20.2 ± 8.9 | 24.6 ± 10.6 | 22.6 ± 11.4 | 40.2 ± 7.6* | 0.02 |
| Proportion type IIx fibres (%) | 0 | 1.0 ± 1.6 | 0.6 ± 1.1 | 1.2 ± 2.1 | ns |
| Proportion type IIx-a fibres (%) | 0 | 0.2 ± 0.3 | 0.3 ± 0.6 | 0.5 ± 0.7 | ns |
| Proportion type I-IIa fibres (%) | 1.5 ± 1.4 | 4.0 ± 6.4 | 2.0 ± 2.3 | 1.6 ± 1.4 | ns |
| Perimeter type I fibres | 330 ± 38 | 332 ± 60 | 295 ± 40 | 320 ± 87 | ns |
| Perimeter type IIa fibres | 380 ± 48 | 348 ± 56 | 274 ± 53* | 303 ± 81 | 0,003 |
| Area type I fibres (μm2) | 7143 ± 1508 | 7315 ± 2471 | 5736 ± 1497 | 6557 ± 2901 | ns |
| Area type IIa fibres (μm2) | 9262 ± 2215 | 7711 ± 2427 | 4880 ± 1970* | 5418 ± 2232 | 0,004 |
| CAF type I fibres (μm) | 6,8 ± 1,1 | 6,8 ± 2,6 | 5,2 ± 0,9* | 5,1 ± 1,2* | 0,006 |
| CAF type IIa fibres (μm) | 6,7 ± 1,9 | 6,3 ± 2,4 | 4,4 ± 0,8* | 4,5 ± 1,0* | 0,002 |
| CAFA type I fibres | 1,0 ± 0,1 | 1,1 ± 0,4 | 1,0 ± 0,3 | 0,9 ± 0,2 | ns |
| CAFA type IIa fibres | 0,8 ± 0,3 | 1,0 ± 0,3 | 1,1 ± 0,3 | 1,0 ± 0,3 | ns |
Data are presented as mean ± SD.
*Significant difference compared to healthy subjects.
n = number of test subjects; CAF = number of capillaries around a single fibre; CAFA = the ratio between CAF and the area of the muscle fibre; ns = not significant