Exploring the Impact of Chronic Intermittent Hypoxia in Obstructive Sleep Apnea on Cardiovascular Remodeling and Endothelial Dysfunction: Mechanisms and Therapeutic Targets

Dr. Aditi Mehra

Department of Cardiovascular Physiology, Malla Reddy Vishwavidyapeeth, Hyderabad

1. Abstract

Obstructive sleep apnea (OSA) is a common disorder related to sleep that involves repeated episodes of upper airway collapse during sleep, resulting in chronic intermittent hypoxia (CIH), disrupted sleep, and cycles of reoxygenation. There is growing evidence that CIH is a key pathophysiological factor connecting OSA to cardiovascular diseases (CVD) such as hypertension, atherosclerosis, coronary artery disease, heart failure, and arrhythmias. The cycles of hypoxia and reoxygenation trigger oxidative stress, systemic inflammation, autonomic imbalance, and metabolic disturbances, leading to endothelial dysfunction and structural changes in the cardiovascular system. These pathological changes appear as vascular stiffness, thickening of the intima-media, myocardial fibrosis, ventricular hypertrophy, and reduced vasodilation, which significantly increase cardiovascular morbidity and mortality in OSA patients. This comprehensive review compiles current experimental, clinical, and translational evidence to clarify the molecular, cellular, and physiological mechanisms through which CIH contributes to endothelial dysfunction and cardiovascular remodeling. Key pathways include the production of reactive oxygen species (ROS), activation of hypoxia-inducible factors (HIFs), excessive sympathetic activity, stimulation of the renin–angiotensin–aldosterone system (RAAS), release of inflammatory cytokines, mitochondrial dysfunction, and epigenetic changes including microRNAs like miR-210. We also examine the interaction between endothelial impairment and myocardial remodeling, highlighting how endothelial dysfunction serves as both an initiating and sustaining factor in structural cardiovascular changes. Finally, emerging therapeutic targets are discussed, such as continuous positive airway pressure (CPAP), pharmacological modulation of RAAS, antioxidants, anti-inflammatory agents, mineralocorticoid receptor antagonists, and new molecular therapies targeting HIF signaling and microRNA pathways. By combining mechanistic insights with therapeutic implications, this review underscores future directions for precision medicine approaches aimed at reducing cardiovascular risk in OSA patients. Understanding CIH-induced cardiovascular remodeling and endothelial dysfunction provides a crucial framework for developing targeted interventions that may significantly improve long-term cardiovascular outcomes.

  Keywords

Obstructive sleep apnea; chronic intermittent hypoxia; endothelial dysfunction; cardiovascular remodeling; inflammation; oxidative stress; sympathetic activation; hypoxia-inducible factors; RAAS; potential therapeutic targets.