Preserved function and reduced angiogenesis potential of the quadriceps in patients with mild COPD

Respiratory Research

Table 2 Quadriceps muscle characteristics

	Controls	Mild COPD	p-value
*Fiber type distribution*
Type I fibers, % total fibers	57 ± 14	55 ± 13	0.59
Type II fibers, % total fibers	43 ± 14	45 ± 13	0.59
*Fiber type area*
Type I fibers, μm²	3403 ± 2691	2486 ± 3416	0.33
Type II fibers, μm²	2635 ± 1868	1919 ± 2683	0.32
Total, μm²	6038 ± 4503	4405 ± 6079	0.32
*Muscle capillarity*
Type I fibers, capillary per fiber	3.80 ± 1.24	3.33 ± 1.04	0.15
Type II fibers, capillary per fiber	2.90 ± 1.04	2.63 ± 0.90	0.35
Total, capillary per fiber	3.38 ±1.09	2.92 ± 0.87	0.10
*Muscle capillarity to fiber area ratio*
Type I fibers, capillary per fiber μm²	1.46 ± 1.56	2.00 ± 1.16	0.16
Type II fibers, capillary per fiber μm²	1.70 ± 1.56	2.51 ± 1.51	0.08
Total, capillary per fiber μm²	1.91 ± 1.78	2.35 ± 1.24	0.30
*Muscle enzymatic activity*
Oxidative profile
HADH, μmol•min^-1•g muscle^-1	2.98 ± 2.56	3.83 ± 4.35	0.47
CS, μmol•min^-1•g muscle^-1	11.86 ± 6.10	14.49 ± 3.66*	0.04
Glycolytic profile
PFK, μmol•min^-1•g muscle^-1	34.59 ± 9.04	31.98 ± 8.32	0.29
*Muscle oxidative stress*
4-HNE, AU	0.99 ± 0.35	1.24 ± 0.67	0.14
OxyBlot®, AU	0.74 ±0.57	1.22 ± 1.46	0.19

Definitions of abbreviations: HADH hydroxyacyl-coenzyme A dehydrogenase, CS citrate synthase, PFK phosphofructokinase, 4-HNE 4-hydroxynonenal, AU arbitrary units. Values are mean ± SD. *p < 0.05 vs. healthy controls.

ISSN: 1465-993X