DPA/AA ratio as a potential biomarker of primary aldosteronism in young and middle-aged adults

Background: Primary aldosteronism (PA) is a common cause of secondary hypertension, yet its diagnosis in young and middle-aged adults remains challenging due to low screening rates and complex testing procedures. Objective: This study aimed to investigate serum polyunsaturated fatty acid (PUFA) profiles, particularly the docosapentaenoic acid/arachidonic acid (DPA/AA) ratio, as novel biomarkers of PA in young adults. Methods: This 1:1 matched case-control study was performed on 138 young and middle-aged patients with PA and 138 essential hypertension (EH) controls. Serum PUFA levels were measured, and their associations with PA were analyzed using univariate and multivariate logistic regression analyses. Using bootstrap to conduct internal validation. The receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were employed to evaluate both the predictive performance and clinical practicability of the model. Results: Young and middle-aged patients with PA exhibited a distinct phenotype, including more severe hypertension, higher fasting blood glucose level, elevated low-density lipoprotein-cholesterol level, lower platelet count, and greater burden of left ventricular hypertrophy and albuminuria. A significantly reduced DPA/AA ratio was the most notable finding in the PA group. The multivariate analysis revealed DPA/AA as a strong independent inverse predictor of PA. Adding DPA/AA to a baseline model of traditional clinical and biochemical variables increased the area under the curve (AUC) from 0.849 to 0.866. The integration into a more comprehensive model also improved the AUC from 0.872 to 0.887. Conclusions: The DPA/AA ratio is a robust, independent biomarker of PA in young and middle-aged adults. Its incorporation into diagnostic models significantly enhances predictive accuracy, thus offering a promising noninvasive approach to improve early detection in this high-risk population.