Abstract
BACKGROUND: The saline infusion test (SIT) to confirm primary aldosteronism requires infusing 2 L of normal saline over 240 minutes. Previous studies raised concerns regarding increased blood pressure and worsening hypokalemia during SIT. We aimed to evaluate the diagnostic applicability of a SIT that requires 1 L of saline infusion over 120 minutes. METHODS: A cross-sectional study, including all patients in a large medical center who underwent SIT from 1 January 2015 to 30 April 2023. Blood samples were drawn for baseline renin and aldosterone (t = 0) after 2 hours (t = 120 min) and after 4 hours (t = 240 min) of saline infusion. We used ROC analysis to evaluate the sensitivity and specificity of various aldosterone cut-off values at t = 120 to confirm primary aldosteronism. RESULTS: The final analysis included 62 patients. A ROC analysis yielded 97% specificity and 90% sensitivity for a plasma aldosterone concentration (PAC) of 397 pmol/L (14 ng/dL) at t = 120 to confirm primary aldosteronism, and an area under the curve of 0.97 (95% CI [0.93, 1.00], P < 0.001). Almost half (44%) of the patients did not suppress PAC below 397 pmol/L (14 ng/dL) at t = 120. Of them, only one (4%) patient suppressed PAC below 276 pmol/L (10 ng/dL) at t = 240. Mean systolic blood pressure increased from 140.1 ± 21.3 mm Hg at t = 0 to 147.6 ± 14.5 mm Hg at t = 240 (P = 0.011). CONCLUSIONS: A PAC of 397 pmol/L (14 ng/dL) at t = 120 has high sensitivity and specificity for primary aldosteronism confirmation.
Original language | English |
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Pages (from-to) | 415-420 |
Number of pages | 6 |
Journal | American Journal of Hypertension |
Volume | 37 |
Issue number | 6 |
DOIs | |
State | Published - 1 Jun 2024 |
Keywords
- blood pressure
- confirmatory test
- cut-off
- hypertension
- plasma aldosterone concentration
- primary aldosteronism
- saline infusion test
- secondary hypertension