The relationship between pulmonary and swallowing functions in patients with neuromuscular diseases followed up by a tertiary referral center: a cross-sectional study

Introduction Respiratory muscle weakness is common in patients with neuromuscular diseases (NMD). This puts them at risk for dysphagia and other pulmonary complications. Objectives To investigate the relationship between pulmonary function and swallowing in NMD. Materials and methods In this cross-sectional study, medical records of patients undergoing treatment at the Tertiary Referral Center for Neuromuscular Diseases of Hospital de Apoio de Brasilia, Brazil, were reviewed. Respiratory function was assessed through spirometry (FVC and FEV1 measured) and swallowing assessed by the Dysphagia Risk Evaluation Protocol and the Functional Oral Intake Scale. Results Two hundred and twenty-two patients were included. Dysphagia was present in 46.8% of patients and impairment of pulmonary function in 64.0%. The mean FVC observed was 66.9% and FEV1 was 66.0%, indicating restrictive lung disease. A correlation between the decline of pulmonary and swallowing functions was observed in patients with NMDs (FVC vs. DREP, R = 0.46; FVC vs. FOIS, R = 0.42; FEV1 vs. DREP, R = 0.42; FEV1 vs. FOIS, R = 0.40, p<.01). FVC and FEV1 values tend to be lower in patients with dysphagia in the context of NMD. Conclusions A positive correlation between pulmonary function and swallowing outcomes was observed in patients with NMD. Despite respiratory and swallowing impairment being widely present in the population with NMD, they require different treatments according to the disease's pathophysiology. Future studies should be conducted to explore the disease-specific relationship between pulmonary function and swallowing in patients with NMD.