Influence of sex gap on muscle strength and functional mobility in patients with cystic fibrosis

Abstract

The objectives of this study were to determine whether there were differences in handgrip strength and functional mobility between patients with cystic fibrosis (CF) and healthy controls with regard to sex and to ascertain whether these differences were related to lung function. Thirty-eight patients with CF (21 women) and 38 healthy controls aged 18–65 years were included. Muscle weakness and functional mobility were assessed through handgrip strength; walking speed; and time, velocity, and power derived from a single sit-to-stand (STS) test. Patients with CF showed differences for STS variables and walking speed but not for handgrip strength, compared with healthy controls. Considering sex differences, female patients showed differences for all variables analyzed while males with CF only exhibited differences for STS variables, compared with healthy controls. Females with CF showed moderate relationship between muscle weakness, functional mobility, and lung function (|r| = 0.45–0.49; p ≤ 0.05) whereas no relationships were observed for males with CF. The influence of chronic infection with Pseudomonas aeruginosa and pancreatic insufficiency on muscle weakness and functional mobility was similar in both sexes. Differences in muscle strength and functional mobility were predominantly observed in females with CF. These results suggest an important effect of sex gap on muscle weakness and functional mobility in patients with CF.