Primary aldosteronism among newly diagnosed and untreated hypertensive patients in a Swedish primary care area

Abstract

Objective. To evaluate the prevalence of primary aldosteronism (PA) in newly diagnosed and untreated hypertensive patients in primary care using the aldosterone/renin ratio (ARR), and to assess clinical and biochemical characteristics in patients with high and normal ARR. Design. Patient survey study. Setting and subjects. A total of 200 consecutive patients with newly diagnosed and untreated hypertension from six primary health care centres in Sweden were included. Main outcome measures. ARR was calculated from serum aldosterone and plasma renin concentrations. The cut-off level for ARR was 65. Patients with an increased ARR were considered for confirmatory testing with the fludrocortisone suppression test (FST), followed by adrenal computed tomographic radiology (CT) and adrenal venous sampling (AVS). Results. Of 200 patients, 36 patients had an ARR > 65. Of these 36 patients, 11 patients had an incomplete aldosterone inhibition during FST. Three patients were diagnosed with an aldosterone producing adenoma (APA) and eight with bilateral adrenal hyperplasia (BHA). Except for moderately lower level of P-K in patients with an ARR > 65 and in patients with PA, there were no biochemical or clinical differences found among hypertensive patients with PA compared with patients without PA. Conclusion. Eleven of 200 evaluated patients (5.5%) were considered to have PA. The diagnosis of PA should therefore be considered in newly diagnosed hypertensive subjects and screening for the diagnosis is warranted.

Key Words::

• Aldosterone
• aldosterone to renin ratio
• family practice
• hypertension
• primary aldosteronism
• renin

Acknowledgements

The authors express their gratitude to the GPs, the participating patients and the staff at the Primary Health Care Centres, Dalby, Linero, Löddeköpinge, Måsen, Nöbbelöv, and Norra Fäladen for their invaluable contribution to the data collection. They would also like to thank Mona Landin-Olsson and Per Katzman, Department of Endocrinology, Skåne University Hospital for helpful collaboration during the final evaluation of the patients with PA.

Funding

The FoUU Foundation, Region Skåne, supported the study financially.

Conflicts of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.