Angiotensin Receptor Expression and Vascular Endothelial Dysfunction in Obstructive Sleep Apnea

Authors:
Open Access
Publisher website
Google Scholar
Abstract
Obstructive sleep apnea (OSA) is associated with vascular endothelial dysfunction (VED) in otherwise healthy patients. The role of renin–angiotensin system (RAS) in the OSA induced VED is not well understood. Recently diagnosed OSA patients with very low cardiovascular disease (CVD) risk (Framingham score ex-vivo effect of AT-1 receptor blockade (ARB) on endothelial superoxide production was also measured before and after CPAP treatment. In OSA patients (n = 11), microcirculatory endothelial AT1 expression decreased from 873 (200) (fluorescence units) at baseline to 393 (59) units after 12 weeks of CPAP (P = 0.02). AT2 expression did not decrease significantly in these patients (479 (75) to 329 (58) post CPAP (P = 0.08)). The ex-vivo addition of the losartan to the microcirculatory endothelium resulted in decreased superoxide expression in the vascular walls from 14.2 (2.2) units to 4.2 (0.8) P < 0.001; while it had no effect on post-CPAP patient tissue (P = 0.64). In OSA patients with no to minimal CVD risk, VED is associated with upregulation of AT-1 expression that is reversible with CPAP. Endothelial oxidative stress was reversible with ARB. RAS activation may play an important role in the development of early CVD risk in OSA patients.
Funding Information
  • National Institutes of Health (R56HL127079-01A1)
  • National Center for Research Resources (ULRR025755)

This publication has 32 references indexed in Scilit: