Chapter 26: Disorders of Blood Flow and Blood Pressure Regulation

The chapter establishes critical connections between obstructive sleep apnea and hypertension development, explaining how recurrent airway collapse during sleep triggers sympathetic nervous system activation and disrupts the normal physiological phenomenon of nocturnal blood pressure dipping, a protective mechanism in which blood pressure naturally decreases during sleep hours. Sleep deprivation and sleep-disordered breathing impair endothelial function and increase vasoconstriction, leading to sustained elevation of systemic blood pressure and increased cardiovascular risk. The chapter also addresses lipoprotein abnormalities as independent contributors to vascular disease, specifically highlighting lipoprotein(a) as an atherogenic particle that combines low-density lipoprotein-like properties with plasminogen-like structure, creating a uniquely proatherosclerotic and prothrombotic phenotype. The discussion integrates how metabolic dysfunction, inflammatory responses activated by repetitive hypoxemia and sleep fragmentation, and abnormal lipid profiles converge to promote atherosclerotic plaque formation and vascular remodeling. The chapter emphasizes that understanding these interconnected mechanisms is essential for identifying high-risk patients and implementing preventive strategies targeting multiple pathways simultaneously. Recognition of sleep-related breathing disorders and lipid abnormalities as modifiable cardiovascular risk factors underscores the importance of comprehensive evaluation and treatment in reducing morbidity and mortality from hypertension and related vascular complications.