Horm Metab Res 2014; 46(06): 427-432
DOI: 10.1055/s-0034-1367033
Endocrine Care
© Georg Thieme Verlag KG Stuttgart · New York

Aldosterone to Active Renin Ratio as Screening Test for Primary Aldosteronism: Reproducibility and Influence of Orthostasis and Salt Loading

S. Pilz*#
1   Department of Internal Medicine, Division of Endocrinology and ­Metabolism, Medical University of Graz, Graz, Austria
2   Department of Epidemiology and Biostatistics, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The ­Netherlands
,
K. Kienreich#
1   Department of Internal Medicine, Division of Endocrinology and ­Metabolism, Medical University of Graz, Graz, Austria
,
M. Gaksch
1   Department of Internal Medicine, Division of Endocrinology and ­Metabolism, Medical University of Graz, Graz, Austria
,
M. Grübler
1   Department of Internal Medicine, Division of Endocrinology and ­Metabolism, Medical University of Graz, Graz, Austria
3   Department of Cardiology, Medical University of Graz, Graz, Austria
,
N. Verheyen
3   Department of Cardiology, Medical University of Graz, Graz, Austria
,
L. A. Bersuch
1   Department of Internal Medicine, Division of Endocrinology and ­Metabolism, Medical University of Graz, Graz, Austria
,
J. Schmid
3   Department of Cardiology, Medical University of Graz, Graz, Austria
,
C. Drechsler
4   Department of Medicine, Division of Nephrology, University of Würzburg, Würzburg, Germany
,
E. Ritz
5   Department of Medicine, Division of Nephrology, University Hospital ­Heidelberg, Heidelberg, Germany
,
A. Moosbrugger
1   Department of Internal Medicine, Division of Endocrinology and ­Metabolism, Medical University of Graz, Graz, Austria
,
V. Stepan
1   Department of Internal Medicine, Division of Endocrinology and ­Metabolism, Medical University of Graz, Graz, Austria
,
T. R. Pieber
1   Department of Internal Medicine, Division of Endocrinology and ­Metabolism, Medical University of Graz, Graz, Austria
,
A. Meinitzer
6   Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
,
W. März
6   Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
,
A. Tomaschitz*
3   Department of Cardiology, Medical University of Graz, Graz, Austria
› Author Affiliations
Further Information

Publication History

received 11 October 2013

accepted 06 January 2014

Publication Date:
13 February 2014 (online)

Abstract

Measurement of the aldosterone to active renin ratio (AARR) is the recommended screening test for primary aldosteronism (PA), but several sampling conditions impact on the AARR. We aimed to evaluate the reproducibility and the influence of orthostasis and salt loading on the AARR. The Graz Endocrine Causes of Hypertension (GECOH) study is a diagnostic accuracy study among hypertensive patients at a tertiary care centre in Graz, Austria. With a median interval of 4 weeks we determined the AARR under standardized sampling conditions twice in the sitting position, after 1h in the supine position, and after a salt infusion test (SIT). We identified 9 patients with PA and 151 patients with essential hypertension (EH). The Pearson correlation coefficient between both AARR measurements in the sitting position was 0.79 (p<0.001). In EH, recumbency was associated with a significant decrease of aldosterone and, to a lesser extent, of renin, thus lowering the AARR as compared to the sitting position (p<0.001 for all). In PA, recumbency had only minor effects, but it increased the rate of false negative AARR. SIT suppressed the AARR and its components in EH, whereas in PA only renin was slightly decreased. AARR has a good intra-individual reproducibility and decreases during recumbency. These results suggest that a single AARR determination in the sitting position is a reliable screening tool for PA.

* These authors contributed equally to the manuscript.


# These authors contributed equally as first authors to the manuscript.