Potentially high prevalence of primary aldosteronism in a primary-care population

Abstract

Primary aldosteronism as a cause of secondary hypertension is suggested to have a prevalence of 15%. 1 Gordon RD Stowasser M Tunny TJ Klemm SA Rutherford JC High incidence of primary aldosteronism in 199 patients referred with hypertension. Clin Exp Pharmacol Physiol. 1994; 21: 315-318 Crossref PubMed Scopus (440) Google Scholar , 2 Anis Anwar Y White WB Mansoor GA Tendler BE Hyperaldosteronism is a common cause of secondary hypertension missed by primary care physicians and associated with normokalaemia. Am J Hypertens. 1998; 11: 199A Crossref Google Scholar , 3 Lim PO Brennan G Shiels P et al. Unexpectedly high prevalence of primary aldosteronism in a hypertensive population in Dundee. British Endocrine Society, Edinburgh1998 Google Scholar These studies have, however, been done in specialist or regional hypertension units that see more patients with resistant hypertension than in primary-care centres. Our centre reported that 16·6% (77 of 495) of patients referred to our hypertension clinic between May, 1995, and January, 1997, had raised ambulant ratio of aldosterone (pmol/L) to renin (ng mL−1 hr−1) of 750 or more. 3 Lim PO Brennan G Shiels P et al. Unexpectedly high prevalence of primary aldosteronism in a hypertensive population in Dundee. British Endocrine Society, Edinburgh1998 Google Scholar Salt loading and fludrocortisone suppression tests confirmed primary aldosteronism in 40 (93%) of 43 patients who were investigated further. A raised aldosterone/renin ratio was, therefore, predictive of primary aldosteronism. We investigated whether the high prevalence of primary aldosteronism was also true in primary-care populations. We screened hypertensive patients in one primary-care population. We obtained approval for the study of the Tayside committee on research medical ethics.