Relation between upper-limb muscle strength with exercise capacity, quality of life and dyspnea in patients with severe chronic obstructive pulmonary disease.

Abstract

In chronic obstructive pulmonary disease (COPD), skeletal muscle weakness is characterized by reduced muscle strength, reduced muscle endurance and the presence of muscle fatigue especially in lower limbs. There has been little research into the upper limb skeletal muscles. In this study, we aimed to investigate the relation of upper limb muscle strength with pulmonary function, exercise capacity, quality of life (QoL) and dyspnea sensation. Eigthy-eight patients (89.8% male; age: 64.2 ± 8.7 years) with COPD (FEV1 = 34.2% ± 15.2%) were evaluated. Tests included hand grip strength and actual 1-repetition maximum (1RM) test for upper limb strength. Dyspnea sensation was assessed with medical research council (MRC) scale. St. George Respiratory Questionary (SGRQ) was used to evaluate patients health related QoL. Exercise capacity was evaluated with incremental shuttle walk test and endurance shuttle walk test. Upper limb muscle strength correlated with exercise capacity but no correlations were found with pulmonary functions.There were negative correlations with all the domains of SGRQ both actual 1RM and handgrip strength. MRC scores revealed a negative correlation with upper limb muscle strength. In our study, we showed that upper limb muscle strength correlated with exercise capacity, QoL, dyspnea sensation. Identifying patients who have greater reductions in strength will allow early interventions with a multidisciplinary manner.