Treatment of obstructive sleep apnoea leads to enhanced pulmonary vascular nitric oxide release.

Background: Obstructive sleep apnoea (OSA) is associated with pulmonary hypertension, however neither the pathogenesis of pulmonary vascular disease nor the effect of successful treatment of OSA on pulmonary vascular physiology has been characterised.

Methods: Seven subjects aged 52 (range 36-63) years with moderate to severe obstructive sleep apnoea (apnoea-hypopnoea index>15/h) had detailed pulmonary vascular reactivity studies, before and after 3 months of successful treatment with nasal continuous positive airways pressure (CPAP). On both occasions, we measured pulmonary pressure, flow velocity, flow and resistance, at baseline and in response to acetylcholine (an endothelium-dependent dilator), sodium nitroprusside (an endothelium-independent dilator), l-NMMA (an antagonist of nitric oxide synthesis) and l-Arginine (the substrate of nitric oxide).

Repetitive hypoxia increases lipid loading in human macrophages-a potentially atherogenic effect.

Obstructive sleep apnea (OSA) is characterized by repetitive episodes of hypoxia and is associated with an increase in cardiovascular disease. We, therefore, investigated the effect of repetitive hypoxia on two key early events in atherogenesis; lipid loading in foam cells and monocyte adhesion to endothelial cells. Human macrophages were loaded with acetylated low-density lipoproteins.

Obstructive sleep apnea and cardiovascular disease.

Obstructive sleep apnea (OSA) is a common disorder associated with an increased risk of cardiovascular disease and stroke. As it is strongly associated with known cardiovascular risk factors, including obesity, insulin resistance, and dyslipidemia, OSA is an independent risk factor for hypertension and has also been implicated in the pathogenesis of congestive cardiac failure, pulmonary hypertension, arrhythmias, and atherosclerosis. Obesity is strongly linked to an increased risk of OSA, and weight loss can reduce the severity of OSA.