Does cystic fibrosis impact skeletal muscles and diaphragm function?

Abstract

Objective: Cystic fibrosis (CF) is a chronic disease with increased malnutrition and loss of muscle strength. The objective of this study is to relate diaphragm and peripheral muscle strength with clinical and physiological functions of CF patients. Methods: 31 adult CF patients (ages:18-42) and 23 healthy subjects were enrolled. Each patient had Body Mass Index (BMI) measured and underwent electromyography (EMG). Right and left rectus femoris thicknesses, diaphragm thickening fraction (DTF) and end-inspiratory thickness of diaphragm were assessed by ultrasonography (USG). Hand dynamometer was used to measure grip strength. Results: None of the patients had neuropathy nor myopathy. Hand grip strength was lower in patients than controls (p=0.003). Patients receiving oral nutritional support had lower handgrip strength than those who were not (p=0.031). Patients had thinner rectus muscles than controls(p=0.000 for both). Patients who had pancreatic insufficiency had thinner rectus muscles than patients without (p=0.033, right and p=0.048, left). Both right and left rectus femoris muscle thicknesses were lower in patients receiving oral nutritional support than those who were not (p=0.010 and p=0.012). DTF was negatively correlated with BMI (p=0.042 and r= -0.368) and positively correlated with handgrip strength (p=0.046 and r=0.361). Conclusion: CF patients had lower muscle thicknesses and handgrip strength than controls. Patients taking oral nutritional support and those with pancreatic insufficiency, had lower rectus femoris thickness and handgrip strength. In CF patients, routine use of USG and hand dynamometer may help predict different clinical parameters.