Primary aldosteronism – prevalence and prognosis in primary care

Context: Several studies have reported primary aldosteronism (PA) as the most frequent cause of a curable secondary arterial hypertension. The excessive aldosterone production caused by mostly unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia is a risk factor for cardiovascular events, metabolic disorders and psychopathological morbidity. This requires an early detection of PA. Yet, the current data about the prevalence is still controversially and based on study populations with prolonged hypertension, already referred to specialized centers.

Objective: Our aim was to analyze the prevalence of PA in primary care among newly diagnosed hypertensive patients.

Design: The study started in November 2012 and was designed as a prospective, multi-centric study in 17 primary care centers in Munich. Blood pressure was measured in all patients willing to participate to the study. When the blood pressure was elevated, screening for PA was performed. Patients with pathological aldosterone-renin-ratio (ARR) underwent further follow-up.

Results: Until November 2013, 66 patients (35 males and 31 females) with hypertension diagnosed within the last year were included. Mean blood pressure was 145 ± 14/92 ± 10 mmHg with no patient taking antihypertensive medication. 3 patients were spontaneously hypokalemic. 20 patients had an elevated ARR. 8 of these 20 patients underwent further confirmatory testing using the saline infusion test which was abnormal in 2 supporting the diagnosis of PA.

Conclusion: Our data demonstrate that at least 3% of patients with newly diagnosed hypertension in primary care are suffering from PA. These findings, if confirmed in a larger study, suggest that screening for PA in patients with low stages of hypertension may be reasonable.