Intermittent hypoxia and atherosclerosis

Abstract

Atherosclerosis is a common pathologic condition that is affecting millions of people in their large and small arteries, including the aorta, coronary, and cerebral arteries. Atherosclerotic lesions are characterized by focal thickening of the vascular tunica intima, through the accumulation of fatty deposits, platelets, and leukocytes in the endothelial cell layer, which eventually form the fatty streaks and plaques inside vascular walls. The subsequent ulceration and rupture of plaques could trigger the formation of thrombi that may partially or completely obstruct blood circulation and cause devastating consequences impairing the function and survival of vital organs. Therefore, atherosclerosis represents a distinguished basis of cardiac, cerebral, and peripheral vascular diseases. This chapter is aimed at providing a comprehensive and non-biased overview on the updated evidence of both detrimental and beneficial effects of intermittent hypoxia in the pathological process of atherosclerosis. Collectively, there is a remarkably abundant body of evidence for an atherogenic role played by chronic and severe intermittent hypoxia. On the other hand, a number of studies originated predominantly by Russian/Ukrainian scientists also demonstrated paradoxical anti-atherosclerosis prophylactic and therapeutic effects, which could be elicited by some well-controlled training/conditioning regimens with often mild or moderate levels of intermittent hypoxia. Considering these most updated evidence and divergent points of view, we have further discussed the possible molecular signaling pathways for both detrimental and protective mechanisms of IH. Nevertheless, many seemingly controversial areas require further investigations, which will undoubtedly bring new insights into the fundamental issue of prevention and treatment of atherosclerosis-associated -cardiovascular diseases.