The role and research progress of epigenetic modifications in obstructive sleep apnoea-hypopnea syndrome and related complications.

Epigenetic modifications are heritable changes in gene expression that do not alter the DNA sequence. Histone modifications, non-coding RNA expression, and DNA methylation are examples of common epigenetic changes. Obstructive sleep apnoea-hypopnea syndrome (OSAHS) is the most common sleep-related breathing disorder, and its incidence is increasing annually, making it a hotspot of clinical research and significantly impacting health and well-being. The main cause of OSAHS is related to complications caused by repeated chronic intermittent hypoxia (CIH). Currently, polysomnography (PSG) and continuous positive airway pressure (CPAP) remain the gold standards for the diagnosis and treatment of OSAHS. However, their limitations-such as time consumption, high cost, and poor patient comfort-contribute to the paradox of high disease prevalence yet low rates of diagnosis and treatment, resulting in a substantial disease burden. In recent years, rapid advances in epigenetics have revealed that biomarkers such as microRNAs (miRNAs), circular RNAs (circRNAs), and other epigenetic modifications hold promise as non-invasive tools for the diagnosis and treatment of OSAHS and its related complications. Although numerous studies have explored epigenetic modifications in other diseases, this study focuses on how epigenetic modifications participate in the process of OSAHS and its related complications, with an aim of elucidating the pathogenesis of OSAHS from an epigenetic perspective and provide new directions for identifying molecular targets for the diagnosis and treatment of OSAHS and related complications.