Low renin hypertension

Abstract

Low or hyporesponsive plasma renin activity (PRA) has been found in approximately one quarter of all patients with essential hypertension and with increased prevalence in blacks, women and older patients. The stability and reproducibility of the low PRA profile over a period of mth to yr remains undocumented. If low PRA is a marker for undiscovered primary causes of hypertension, then this low PRA profile should be stable. The etiology of low PRA hypertension remains unknown but many have invoked unidentified mineralocorticoids and unexplained volume expansion. There is no persuasive evidence that either hypothesis is correct. The possibility must be examined that low PRA may represent a stage of, or response to, essential hypertension rather than a distinct disease entity. Some authors have concluded that patients with low PRA hypertension suffer fewer cerebrovascular and cardiovascular accidents than normal or high PRA patients. There is substantial evidence contradicting this viewpoint, but a definitive resolution will require a prospective, carefully controlled study where the effects of blood pressure can be separated from the adverse effects of renin, i.e., angiotensin II. It appears that diuretic therapy may be more useful in low renin hypertension, but considering the authors' current knowledge, the major therapeutic guideline should be effective blood pressure control.