Pathogenesis and therapy resistant hypertension in patients with obstructive sleep apnea. The role of aldosterone

Abstract

Resistant hypertension is defined as blood pressure remaining above goal (< 140/90 mm Hg) despite the concurrent use 3 antihypertensive agents of different classes including diuretics in optimal doses. Recent studies have shown that hypertension resistant do therapy is not a rare diseases but occurs in approximately 12–15% of all patients with hypertension. The most common because 60–80% causing resistant hypertension is obstructive sleep apnea (OSA). The pathogenesis of hypertension in patients with OSA is complicated. A very important reason is increased sympathetic activity caused by repetitive apnea. Other factors are oxidative stress and chronic inflammation that accompanies OSA. Chronic inflammation has been shown in many works can lead to the development of hypertension. In the course of OSA have shown increased activity of the renin-angiotensin-aldosterone system and endothelial dysfunction. Reduced glomerular filtration lead to progressive renal failure, which in turn causes an increase in blood pressure. Recently drew attention to the relatively high prevalence (20–30%) of elevated levels of aldosterone in blood in patients with OSA. Several authors have shown that the increase in aldosterone levels in serum correlates with the severity of OSA. Aldosterone excess in combination with high sodium diet leading to water retention, swelling of the mucous membranes of the throat and obstructive airways.

In lifestyle changes patients with hypertension and OSA should pay attention to weight reduction and dietary salt restriction. The use of CPAP mostly only slightly lowers blood pressure during day. ACE inhibitors and sartans, calcium antagonists and diuretics (thiazides, indapamide or furosemide) are used in pharmacological treatment. Some authors have successfully used beta and alpha blockers. However, the most effective is to add aldosterone blockers. These drugs reduce blood pressure more than other groups of antihypertensive agents and are also effective in lowering the blood pressure in patients with normal serum aldosterone levels. Gaddam et al. also demonstrated that spironolactone significantly reduce the severity of OSA.