Study of peripheral muscle strength and severity indexes in individuals with chronic obstructive pulmonary disease

Abstract

Individuals with chronic obstructive pulmonary disease (COPD) present reduced peripheral muscle strength, which leads to impaired mobility and increased mortality risk. However, it is not clear whether there is any relationship between muscle strength, muscle mass and the body mass index, airflow obstruction, dyspnea, exercise performance (BODE) index scale, which is considered to be the best predictor of survival for individuals with COPD. The BODE Index is a multidimensional system that measures body composition (B), airway obstruction (O), dyspnea perception (D) and the ability to exercise (E), and rates the severity of the major changes found in individuals with COPD. The objective of this study was to verify any relationship between the BODE Index, muscle mass and maximum muscle strengths of the upper limb (UL) and lower limb (LL) in subjects with moderate to very severe COPD. Twenty-six individuals with moderate to very severe COPD were evaluated by body composition (body mass index and muscle mass), BODE Index, handgrip strength (HS) and one repetition maximum (1RM) test of the UL and LL. There was a positive correlation (Pearson, p < 0.05) of peripheral muscle strength, evaluated by HS and 1RM (pectoral and triceps, round muscles and dorsal section, quadriceps), to muscle mass (0.74, 0.57, 0.74 and 0.62, respectively) and the distance walked in the six-minute walking test (0.52, 0.50, 0.46 and 0.58, respectively), but no correlation of muscle strength was found to forced expiratory volume in one second to dyspnea or the BODE Index. In accordance with the results of this study, peripheral muscle strength as measured by HS and 1RM is not related to the severity indexes for COPD, unlike UL and LL muscle strength. Therefore, UL and LL measurements now have an additional importance in COPD evaluation.