Oxidative Stress and Inflammation in Hypoxemic Respiratory Diseases and Their Comorbidities: Molecular Insights and Diagnostic Advances in Chronic Obstructive Pulmonary Disease and Sleep Apnea.

In chronic respiratory diseases (CRDs), oxidative stress and inflammation are closely linked, driving disease onset, progression, and comorbidities. Oxidative stress activates inflammatory pathways, while chronic inflammation promotes further reactive oxygen species (ROS) production, creating a vicious cycle leading to airway remodeling, reduced lung function, and exacerbations. This review highlights the central roles of inflammation and oxidative stress in chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA). In COPD, chronic hypoxemia associates with emphysema, appearing with disease progression. In OSA, beyond systemic consequences, pulmonary inflammation and oxidative stress contribute to lung injury as well. Although COPD and OSA are distinct conditions, some patients present with "overlap syndrome", a term used in this review to describe the coexistence of both. This combination poses unique diagnostic and therapeutic challenges. We also examine the role of hypoxia and its transcriptional effects via hypoxia-inducible factors (HIFs) in promoting oxidative stress and inflammation. Finally, we explore how artificial intelligence (AI) offers promising tools to improve diagnosis, monitoring, and management of CRDs and may help elucidate mechanistic links between hypoxia, inflammation, and oxidative stress, contributing to more personalized therapeutic strategies.