Association between arterial stiffness, disease severity, and exercise muscle oxygenation in young adults with cystic fibrosis

<bold>Background:</bold> Arterial stiffness (AS) predicts cardiovascular disease in chronic pulmonary disease. <bold>Objective:</bold> To investigate the association between AS and lung function, disease severity, exercise capacity, and muscle oxygenation (SMO₂) in adults with cystic fibrosis (CF). <bold>Methods:</bold> Nineteen CF patients (age=20.6±3.1 years, 6M, 13F, FEV₁=76.5±22.0%) were included. Lung function was measured using spirometer. Disease severity was determined using the FACED score (FEV₁% predicted, age, chronic colonization by Pseudomonas aeruginosa, radiological extent of the disease, and dyspnea [Medical Research Council Dyspnea Scale]). Exercise capacity was assessed using a six-minute walk test (6MWT). The SMO₂ was evaluated during 6MWT. AS was measured via the brachial index (augmentation index normalized to 75 bpm heart rate, AIx@75), and total vascular resistance, TVR). <bold>Results:</bold> Alx@75 was 28.0±11.9%, and TVR was 1571.4±203.1 dyn s/cm⁵. The FACED score was 1.3±1.1, and the 6MWT distance was 602.0±69.5 m. Alx@75 was related to FACED score (r=0.462), minimum SMO₂ (r=-0.542), and recovery SMO₂ (r=-0.527, p&lt;0.05). TVR was correlated with FACED score (r=0.599), FEV₁ (r=-0.476), FVC (r=-0.483), FEF_25-75% (r=-0.473), and minimum (r=-0.647), maximum (r=-0.683), and recovery SMO₂ (r=-0.613, p&lt;0.05). <bold>Conclusions:</bold> AS is associated with higher disease severity, impaired SMO₂, and lung function in young adults with CF. Higher AS, disease severity, and impaired lung function may be associated with poorer intra-muscular oxygenation in young adults with CF. Supported by Hacettepe University Scientific Research Project Coordination Unit.