<qa>  What is the RAAS triggered early in the course of renal disease?In summary: Activation of the RAAS occurs early in the course of renal disease and both angiotensin and aldosterone are likely to be important factors in the pathogenesis of arterial stiffness, LVH and autonomic dysfunction. ACE inhibitors reduce arterial stiffness and LVH as well as the progression of renal dysfunction but levels of circulating aldosterone may remain high and the effects of aldosterone inhibition are unknown. 