Alterations in the muscle-to-capillary interface in patients with different degrees of chronic obstructive pulmonary disease

Table 3 Muscle-capillary interface parameters 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
C:F_i type I	2.7 ± 0.5	2.7 ± 1.3	2.0 ± 0.4*	2.0 ± 0.5*	0.007
C:F_i type IIa	2.5 ± 0.5	2.5 ± 1.1	1.6 ± 0.4*	1.7 ± 0.4	0.002
CFPE type I	8.3 ± 1.1	8.1 ± 3.0	6.8 ± 0.9*	6.2 ± 0.6 *	0.002
CFPE type IIa	6.6 ± 0.9	7.3 ± 2.6	5.9 ± 0.8	5.8 ± 1.1	ns
LC type I	72.4 ± 8.4	77.0 ± 25.0	58.8 ± 14.6	67.4 ± 29.0	ns
LC type IIa	64.8 ± 19.5	64.7 ± 17.8	45.2 ± 10.6	57.4 ± 25.8*	0.03
LC/PF type I	21.8 ± 1.4	22.3 ± 5.6	20.0 ± 4.7	20.4 ±4.1	ns
LC/PF type IIa	17.5 ± 2.5	19.0 ± 4.1	16.3 ± 2.2	18.2 ± 2.5	ns

Data are presented as mean ± SD.
*Significantly lower compared to healthy subjects.
n = number of test subjects; C:F_i = the sum of the fractional contributions of all capillary contacts around the fibre, i.e. the individual capillary-to-fibre ratio; CFPE = quotient between C:F_i and the fibre perimeter; LC = length of capillaries in contact with muscle fibre; LC/PF = ratio between LC and fibre perimeter; ns = not significant.

ISSN: 1465-993X