Análise da força muscular periférica por dinamometria isocinética em pacientes em tratamento para fibrose cística

Abstract

Introduction: Cystic fibrosis (CF) is an autosomal recessive genetic disease characterized by chronic and recurrent respiratory infections, pancreatic insufficiency, and increased sweat chloride concentration. Respiratory complications are the main contributors to increased morbidity and mortality in CF. Furthermore, disease progression is associated with changes in respiratory mechanics, metabolic disorders, malnutrition, and musculoskeletal complications. Objective: To analyze the association between peripheral muscle strength and pulmonary function and functional performance in adolescents and adults with CF. Methodology: Cross- sectional study, conducted between December 2024 and April 2025, with 22 clinically stable CF patients, aged ≥14 years. Participants underwent clinical evaluation, body composition by bioimpedance, spirometry, handgrip strength, 6-minute step test, and isokinetic dynamometry of the lower limbs. Individuals were stratified into two groups according to the FEV₁ Z-score: G1 (no lung alteration) and G2 (with lung alteration). Statistical analysis was performed with a significance level of p<0.05. Results: The sample consisted mostly of men (63.6%), with a mean age of 24.9 years. Of the 22 patients evaluated, 10 presented some degree of alteration in pulmonary function. The only variable that presented a statistically significant difference between the groups was the power of the flexor muscles at 60°/s, which was significantly lower in the group with altered pulmonary function (p = 0.03). There was no significant difference in performance on the 6-minute step test between the groups. Discussion: The results demonstrate that pulmonary dysfunction is associated with reduced strength and, mainly, peripheral muscle power, even in clinically stable patients. Muscle power was shown to be sensitive to identify early functional alterations, especially in the lower limbs. Regular physical activity and multidisciplinary monitoring can contribute to preserving functionality in these patients. Conclusion: The mean muscle power of the flexor muscles was significantly lower in patients with altered pulmonary function, indicating that this parameter may be an early marker of functional impairment in individuals with cystic fibrosis.