Diaphragmatic Dysfunction and Systemic Leukotrienes: Exploring the Connection in Chronic Obstructive Pulmonary Disease.

Abstract

<bold>Introduction:</bold> Chronic obstructive pulmonary disease (COPD) arises from persistent inflammation, yet the role of leukotrienes in its pathogenesis remains unclear. This study aimed to assess systemic leukotriene levels in COPD patients compared to controls and correlate these with disease severity and clinical parameters. <bold>Methods:</bold> A case-control study was conducted at La Rabta Hospital between September and December 2023, including 40 male patients with stable COPD and matched controls. Exclusion criteria were other respiratory diseases or immunosuppressive treatments. Disease severity was classified using the 2022 GOLD ABCD system. Blood samples measured leukotrienes (LT) B4, D4, E4, F4, and C-reactive protein. Spirometry and diaphragmatic ultrasound assessed thickening (DT), thickening fraction (TF), and maximal diaphragmatic excursion (DEmax). <bold>Results:</bold> Participants had a mean age of 63.78 ± 7 years. COPD was categorized as Group B and Group E in 40% of cases each. Median TF was 22.8 mm (IQR: 22.58-24.29 mm). Canonical correlation linked leukotriene levels with ultrasound parameters. LTE4 negatively correlated with DT in Group E (r = -0.377; P <0.001). DEmax was lower in patients with anorexia, severe bronchial obstruction, and CAT scores > 20 (P = 0.015). LTD4 negatively correlated with TF in chronic respiratory failure (r = -0.347; P < 0.001). TF predicted severe exacerbations with 90% sensitivity and 92% specificity. <bold>Conclusion:</bold> Combining diaphragmatic ultrasound and leukotriene profiling may offer a personalized approach to COPD management.