Network modules uncover mechanisms of skeletal muscle dysfunction in COPD patients

Table 1 Characteristics of the study groups

	Healthy	COPD
Sex (M/F)	10/2	15/0
Age, years	65 ± 9	69 ± 7
FFMI, kg/m²	21 ± 2	19 ± 3
FEV₁, L (mean % pred)	3.46 ± 0.69 (107)	1.34 ± 0.37 (46)*
FEV₁/FVC	0.75 ± 0.04	0.43 ± 0.08*
VO₂ peak, L/min (mean VO₂ peak/kg)	1.70 ± 0.5 (22)	0.91 ± 0.3 (14)*
[La]a peak, mEq/L	10.60 ± 2.7	6.8 ± 2.3*
VO₂ peak training diff (post–pre), L/min	0.25 ± 0.11^†	0.14 ± 0.18^†
[La]a training diff (post–pre), mEq/L	− 4.60 ± 0.6^†	− 1.5 ± 2^†

Results are expressed as mean ± SD
In the post-training study, lactate measurements during constant-work rate exercise were done at the same workload and duration than the pre-training exercise protocol
FFMI fat free mass index, FEV₁ forced expiratory volume in the first second, FEV1/FVC FEV₁ to forced vital capacity ratio, VO₂ peak peak oxygen uptake difference post minus pre-training, [La]a arterial lactate concentration difference
Unpaired t test was used to compare controls and COPD, * P < 0.05. Paired t test was used to compare post-training and baseline time points in both healthy controls and COPD patients, ^†P < 0.05. Low FFMI was defined as < 17.05 kg/m² for men [21]. It is of note that three COPD patients were discarded from the analysis because they did not pass the Agilent analysis

ISSN: 1479-5876