[The value of renin determination in the diagnosis of hypertension]

Primary aldosteronism and renovascular hypertension are two different diseases in which renin determinations are necessary for establishment of diagnosis or therapeutic procedure. Low renin values which are not stimulated by acute stimuli combined with elevated plasma aldosterone concentrations confirm the diagnosis of primary aldosteronism. When in a patient with proven renal artery stenosis a significant difference in renal venous renin activity is observed between the two kidneys, a connection between hypertension and renal artery stenosis is likely when in addition the renin secretion of the unaffected kidney is suppressed. A favourable outcome for surgery can be predicted when the individual clinical picture in such a case is also considered. A similar view also holds for the connection between hypertension and unilateral small kidney not due to renal artery stenosis. In essential hypertension the plasma renin level makes it possible to a certain extent to predict whether a patient will benefit from diuretics or from beta-blocking agents. Despite this experience, however, renin determinations are not indicated in every case of essential hypertension. It has not been proven that the prognosis of this disease is improved by renin oriented monotherapy rather than by effective treatment with other antihypertensive agents.