Evaluation of Patients Performed with Saline Infusion Test with a Pre-Diagnosis of Primary Hyperaldosteronism

Abstract

Background Primary hyperaldosteronism (PHA) is a primarily treatable cause of arterial hypertension characterized by low plasma renin and high aldosterone levels. The prevalence of secondary hypertension as a common endocrine cause is 5-13%. The plasma aldosterone/renin ratio (ARR) is the best available method for PHA screening. One or more confirmatory tests may be required to confirm or exclude patients' diagnoses. One frequently used confirmatory test is the saline infusion test (SIT). We aimed to screen the patients who underwent SIT with the preliminary diagnosis of PHA and to compare the results of the patients diagnosed with essential hypertension (EH) and PHA. Material and Methods Seventy-seven patients with a history of drug-resistant hypertension or unexplained spontaneous or diuretic-induced hypokalemia or adrenal incidentaloma, or a family history of earlyonset hypertension or cerebrovascular accident at a young age (<40 years) and undergoing saline infusion testing were included in the study. Results Twenty-six (33.8%) of the patients were male, and 51 (66.2%) were female. The mean age of the patients was 54.5±13.7 years. EH was present in 39 (50.6%) patients, and PHA was present in 38 (49.4%) patients. Patients with PHA and EH were compared. There was no significant difference between mean systolic blood pressure, diastolic blood pressure, potassium, and aldosterone renin ratio (ARR) in the two groups (p>0.05). Basal plasma aldosterone (p<0.05), SIT 0 th , and 4 th -hour plasma aldosterone levels (p<0.01) was significantly higher in PHA than in EH. Aldosterone synthesizing adenoma (ASA) and idiopathic hyperaldosteronism (IHA) were compared. There were no significant differences between basal plasma aldosterone, SIT 0 th , and 4 th -hour plasma aldosterone levels, ARR, and potassium values (p>0.05). The mean sodium value was significantly higher than the IHA (p <0.05). Conclusions Our study determined that the saline infusion test could be used to confirm the diagnosis of primary hyperaldosteronism. Its use alone was not sufficient in the differential diagnosis of aldosteronesynthesizing adenoma and idiopathic hyperaldosteronism.