Diagnostic Utility of Aldosterone/Direct Renin Concentration Ratio in Iraqi Patients with High Arterial Blood Pressure: A Pilot Study

Abstract

Objectives: Primary aldosteronism is a prevalent contributor to secondary hypertension, posing an elevated risk of morbidity and mortality. The initial step in diagnosing this condition involves screening individuals suspected of having it.

Methods: In our study, we enrolled 50 patients who were suspected of having hyperaldosteronism. We provided specific recommendations and instructions to these patients concerning drug therapy and implemented measures to enhance testing accuracy. The tests were conducted using the Chemiluminescence Immunoassay (CLIA) system procedure, relying on plasma direct renin concentration rather than activity. Our findings were meticulously validated, compared, and aligned with the references from ARUP laboratories.

Results: Among our participants, 4 patients (8%) were unequivocally diagnosed with primary aldosteronism based on the Aldosterone Direct Renin Concentration (ADRR) criteria. These patients exhibited the trifecta of hypokalemia, elevated aldosterone levels, and diminished renin levels, obviating the need for further confirmatory testing. Furthermore, 13 patients (26%) were deemed likely candidates for primary aldosteronism, given their plasma aldosterone levels exceeding 15 ng/dl and renin levels below 2.5 pg/ml. Additionally, 7 patients (14%) displayed strong indications of primary aldosteronism, characterized by plasma aldosterone levels surpassing 21 ng/dl and plasma renin concentrations below 2.5 pg/ml, accompanied by high ADRR values. However, both the "likely" and "strong indication" groups necessitated confirmatory testing. Notably, our results revealed no significant disparities in age, gender, personal or family history of atherosclerotic cardiovascular disease (ASCVD), or the presence of adrenal adenomas between patients diagnosed with primary aldosteronism and those in the non-aldosteronism group within the study.

Conclusion: Primary aldosteronism is a prevalent health concern, warranting the screening of highly suspicious patients. Utilizing direct renin concentration, instead of renin activity, offers a straightforward, cost-effective, rapid, and reproducible method for diagnosis.