Prevalence of Primary Aldosteronism in Newly Diagnosed Hypertensive Patients in Primary Care.

Context: Primary aldosteronism (PA) represents the most frequent cause of endocrine arterial hypertension. PA is also common in patients with mild forms of hypertension and normokalemia.

Objective: To identify the prevalence of PA in newly diagnosed hypertensive patients in primary care in Southern Germany.

Patients and methods: Newly diagnosed hypertensive patients in 27 primary care centers in Munich agreed to participate in the study. Patients were screened for PA using the aldosterone-to-renin ratio (ARR). In case of elevated ARR, confirmation testing was performed. After the diagnosis of PA, subtype differentiation and subsequent therapy of PA were initiated.

Results: A total of 235 patients with newly discovered arterial hypertension were initially screened for PA. Among these, 35 were excluded because the medication indicated pre-existing treated arterial hypertension or they were on interfering antihypertensive medication. At the first screening, 2.0% of the patients had hypokalemia. Of the 200 patients with newly discovered arterial hypertension, 42 had an elevated ARR. The incidence of the presence of hypokalemia did not differ according to normal or pathological ARR. Nine patients (21%) did not show up for further testing and were lost to follow-up, and 33 patients underwent a saline infusion test. Of these, 11 patients were diagnosed with PA, leading to at least 5.5% prevalence of PA in the collective. None of the diagnosed PA patients was hypokalemic at screening.

Conclusion: A 5.5% prevalence of PA was observed in our data of untreated newly diagnosed patients with hypertension.