SAT-247 Impact of Age, Sex and Race on Primary Aldosteronism Test Interpretation: Implications for Broad Screening

Abstract Disclosure: A.J. Newman: None. L.C. Tsai: None. E.E. Abel: None. A. Ferrebus: None. J. Chan: None. S. Mahrokhian: None. I. Hanna: None. K. Foote: None. C. Tsai: None. S. Parisien-La Salle: None. J.M. Brown: None. A. Vaidya: None. Background: Increasing recognition of the prevalence of primary aldosteronism (PA) over the last decade has motivated recommendations for broad screening for PA in all hypertensive patients. However, successful interpretation of screening results requires a thorough understanding of how biochemical tests for PA are affected by demographic characteristics such as age, sex and race. Methods: 857 hypertensive adults from across the US who met at least one guideline criterion for testing for PA underwent local phlebotomy for aldosterone and renin at a national reference laboratory without adjustment of background medications. All results were analyzed via LC-MS/MS and interpreted using a standardized algorithm, including classification as positive or negative PA screen based on pre-determined renin, aldosterone and aldosterone-to-renin ratio (ARR) criteria. Estimated marginal means were used to adjust renin, aldosterone and ARR values for participant demographics, renal function, history of coronary artery disease, and medications known to alter these tests. Logistic regression was used to identify predictors of positive test results. Results: Participant diversity was reflected by a mean age 62 ± 11 y, 55% women, 14% Black and 23% Hispanic. Older participants had lower adjusted mean aldosterone and renin: those 70 years and older had 24% lower aldosterone (P < 0.05) and 48% lower renin activity (P < 0.001) when compared to those under 50 years. However, the decline in renin outpaced that of aldosterone, resulting in a trend toward a higher ARR with older age (52% higher, P = 0.14). On average, aldosterone concentrations were 11% higher in women than men, and this disparity persisted across the lifespan, even as aldosterone declined with age in both sexes. Compared with white participants, Black participants had an 81% higher ARR than white participants (P < 0.001), primarily driven by significantly lower renin (P < 0.005), and these differences persisted across age groups. Of clinical relevance, participants ≥ 70 years old had a 19% higher odds of a positive PA screen than those < 50 y (P = 0.002), whereas Black participants had a 22% higher odds of a positive PA screen than white participants (P < 0.001). Sex did not significantly modify the odds of positive screen accounting for other variables, including medications. Conclusions: In this large, diverse, nationwide sample, women had higher aldosterone levels than men across the lifespan, older participants had lower aldosterone and renin, but higher ARR, and Black participants had lower renin and significantly higher odds of testing positive for PA. These findings highlight the critical influence of demographic factors on interpreting PA testing results and informing guideline recommendations. Presentation: Saturday, July 12, 2025