The primary object of the study is to estimate the effect of addition of low dose spironolactone to antihypertensive treatment with at least three antihypertensive drugs in patients with type-2 diabetes and blood pressure over 130/80 mmHg.~Secondary aims are to estimate how many of these patients have their blood pressure controlled by the addition of spironolactone, to investigate whether the addition of spironolactone affects insulin sensitivity and urinary protein secretion and to estimate the incidence of adverse effects of the aldosterone antagonist.
The purpose of this study is to estimate the effect of spironolactone on blood pressure resistant to therapy in type-2 diabetics.