High frequency of primary hyperaldosteronism among hypertensive patients from a primary care area in Sweden

Objective. To search for primary hyperaldosteronism (PHA) among previously known hypertensive patients in primary care, using the aldosterone/renin ratio (ARR), and to evaluate clinical and biochemical characteristics in patients with high or normal ratio. Design. Patient survey study. Setting and subjects. The study population was recruited by written invitation among hypertensive patients in two primary care areas in Sweden. A total of 200 patients met the criteria and were included in the study. Main outcome measures. The ARR was calculated from serum aldosterone and plasma renin concentrations. The cut-off level for ARR was set to 100, as confirmed in 28 healthy subjects. Patients with increased ARR were considered for a confirmatory test, using the fludrocortisone suppression test. Results. Of 200 patients, 50 patients had ARR >100; 26 patients were further evaluated by fludrocortisone suppression test. Seventeen of these patients had an incomplete aldosterone inhibition. Conclusion. In total 17 of 200 evaluated patients (8.5%) had an incomplete suppression with fludrocortisone. This confirms previous reports on a high frequency of PHA. No significant biochemical or clinical differences were found among hypertensive patients with PHA compared with the whole sample.