Etiology and Pathophysiology of Obstructive Sleep Apnea

Primary Pathophysiologic Mechanism

The American Geriatrics Society notes that obstructive sleep apnea involves obstruction of the upper airway manifested by greatly diminished or absent airflow despite continued respiratory effort 2
The European Respiratory Society indicates that the pharyngeal and/or laryngeal airway collapses during sleep due to elevated mechanical loads exceeding compensatory neuromuscular responses 3
The American Geriatrics Society reports that episodes result in hypoxemia, autonomic nervous system changes, and sleep fragmentation through recurrent arousals 2

The American Academy of Pediatrics states that craniofacial anomalies, including micrognatia and macroglosia, significantly increase the risk of obstructive sleep apnea 5
The European Respiratory Society notes that pharyngeal fat deposits from obesity decrease pharyngeal patency and increase critical closing pressure 3

The American College of Cardiology recommends that a 10% increase in body weight within 4 years produces a six-fold increase in odds ratio for developing obstructive sleep apnea 3
The European Respiratory Society indicates that weight gain has a greater influence on increasing apnea-hypopnea index (AHI) than weight loss has on decreasing it 3
The American College of Cardiology notes that obesity is the single most important modifiable risk factor, present in 60-90% of obstructive sleep apnea patients 1

The American Geriatrics Society reports that male sex confers 2-3 times higher prevalence of obstructive sleep apnea than females 1
The Journal of the American Geriatrics Society states that obstructive sleep apnea is much more common in postmenopausal than premenopausal women 2
The American Geriatrics Society notes that prevalence increases with aging in both genders 2

The American Heart Association states that heart failure, atrial fibrillation, and stroke are more common in obstructive sleep apnea patients and may worsen the condition 2
The American Geriatrics Society reports that hypothyroidism is often associated with obstructive sleep apnea, particularly in women 2
The American Diabetes Association notes that diabetes mellitus and insulin resistance show an association with obstructive sleep apnea 2

The American Geriatrics Society recommends that one should not assume elderly obstructive sleep apnea patients must be obese - older adults with obstructive sleep apnea may have normal weight 2
The American Academy of Pediatrics states that one should consider obstructive sleep apnea in males with nocturia - this symptom is commonly misattributed to prostatic hypertrophy rather than obstructive sleep apnea 2
The American Heart Association notes that one should evaluate for obstructive sleep apnea in patients with unexplained syncope, especially those with cardiovascular risk factors 4