Endothelial abnormalities found in patients with obstructive sleep apnea

Butt M. Hypertension. 2011;doi:10.1161/hypertensionaha.111.170910.

Issue: September 2011

Researchers in a recent study have observed concomitant endothelial dysfunction and impaired myocardial perfusion in otherwise normal patients with moderate-to-severe obstructive sleep apnea. However, with the use of continuous positive airway pressure therapy, they found that patients had marked improvements in these abnormalities at 6 months.

To obtain these findings, the United Kingdom-based study group used real-time quantitative myocardial contrast echocardiography to assess myocardial perfusion, while concurrently measuring macrovascular and microvascular endothelial dysfunction, in normotensive individuals (n=36) with moderate-to-severe obstructive sleep apnea. This group was matched with hypertensive controls and healthy controls (n=36 for each).

Researchers reported that compared with healthy individuals, those with obstructive sleep apnea and hypertension had abnormal myocardial perfusion, cutaneous perfusion responses and attenuated brachial artery reactivity (P<.001 for all comparisons). Treatment with continuous positive airway pressure (CPAP) therapy for 26 weeks, however, led to significant reductions for both hypertensive and sleep apnea patients in all three areas: brachial artery reactivity (P<.001), cutaneous perfusion responses (P<.001) and myocardial perfusion (P<.01).

“The findings should change how doctors treat patients with obstructive sleep apnea,” Gregory Y.H. Lip, MD, lead study author and professor of cardiovascular medicine, University of Birmingham in the United Kingdom, commented in a press release. “Even apparently healthy patients with sleep apnea show abnormalities of small and large blood vessels, as well as impaired blood supply to the heart muscle, and these can improve with CPAP therapy.”

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