Blockers of renin angiotensin aldosterone system (RAAS) are considered the standard of care in treatment of diabetic nephropathy. Their effects are thought to be through multiple mechanisms, including reducing intraglomerular pressure. However, due to the lack of a sensitive, practical and noninvasive method of monitoring renal hemodynamics, the magnitude of hemodynamic effects of these agents and its contribution to proteinuria reduction has not been studied in humans. At the same time, it is not clear if treatment with blockers of the RAAS have similar renal hemodynamic effects in individuals with and without diabetes and kidney disease.