In patients with OSA frequent episodes of hypoxemia during sleep result in the repeated activation of the sympathetic nervous system. What is more, the episodes of respiratory disorders increases in levels of aldosterone serum concentration with following sodium and water retention and elevation of blood pressure finally. An increased aldosterone level also stimulates synthesis of collagen, promotes stiffening of the arterial wall, myocardial fibrosis with heart muscle remodeling and takes part in development of left ventricular hypertrophy (LVH) - common complication of hypertensive patients with OSA. Several studies, including the Sleep Heart Health Study have confirmed that severe OSA is associated with high prevalence of concentric hypertrophy through sympathetic activation and vasoconstriction.