Prevelence of primary aldosteronism in an urban hypertensive population

Objective: To determine the prevalence of primary aldosteronism (PA) in hypertensive patients presenting to the primary care clinic at The Mount Sinai Hospital, regardless of the degree of hypertension and to identify clinical criteria that should prompt screening for PA. Methods: An aldosterone:renin ratio (ARR, cutoff ≥20, with plasma aldosterone concentration [PAC] ≥10 and suppressed renin) was used to prospectively screen 296 hypertensive patients (blood pressure [BP] ≥140/90) over the age of 18 from August 2012 through May 2013. Subjects who screened positive then underwent confirmatory oral salt load testing (OSLT). Results: Of the 296 patients, 14 screened positive for PA, an overall prevalence of 4.7%. Six of the 14 cases underwent confirmatory OSLT, upon which 2 were confirmed positive, for a prevalence of 0.7%. Overall, patients with confirmed PA were more likely to have resistant hypertension (42.9% vs. 18.1% (P =.0334)) and require more antihypertensive agents (2.8 ± 1.2 agents vs. 2.1 ± 1.1 agents, P =.0213). There was a trend toward lower potassium values in the cases. Conclusion: The prevalence of PA in our clinic is much lower than in reports from certain "at-risk" populations. PA screening is indicated in patients with resistant hypertension, regardless of serum potassium levels.