Peripheral muscle function performance and sex differences among patients with chronic obstructive pulmonary disease

<bold>Background:</bold> The in-depth assessment of peripheral muscle function may help to improve exercise training prescriptions in patients with chronic obstructive pulmonary disease (COPD). <bold>Objective:</bold> To investigate upper and lower limb muscle function, their relationship, and sex differences in patients with COPD. <bold>Methods:</bold> Baseline data of patients with COPD referred for pulmonary rehabilitation (PR) from two previous studies by our group (<ext-link>NCT04767126</ext-link> and <ext-link>NCT04785469</ext-link>) were retrospectively analyzed. Participants were assessed for their fat-free mass (FFM), upper and lower limb muscle function [i.e. muscle quality, isometric handgrip (HGS) and quadriceps (QS) strength, functional leg muscle power and rate of force development (RFD)], and functional exercise capacity [5-repetition sit-to-stand (5STS)]. <bold>Results:</bold> Forty-seven COPD patients (45% were women; age 69 ± 8 years; FEV1 48 ± 20 percentage of predicted) were included in the analysis. Sarcopenia was found in 38% of patients (♀ vs ♂=52% vs 27%), whereas 26% and 38% of patients showed reduced HGS (♀ vs ♂=24% vs 27%) and QS (♀ vs ♂=24% vs 50%), respectively. Male patients showed better leg muscle quality (p=0.036) and QS (p=0.029) than women. There were positive correlations between HGS and QS (p<0.001), RFD (p<0.001), functional leg muscle power (p<0.001) and FFM (p<0.001), as well as a negative correlation between HGS and 5STS (p=0.021). <bold>Conclusion:</bold> A relevant proportion of patients with COPD referred for PR may require specific muscle training, in particular lower limb muscles of male patients. The use of HGS as a simple measure to estimate lower limb muscle function in patients with COPD should be further investigated.