Impact of Age, Sex, and Race on Primary Aldosteronism Test Interpretations

BACKGROUND: New guidelines recommend testing for primary aldosteronism (PA) in all people with hypertension. Interpreting population-based results for PA will require understanding the influence of demographic characteristics. METHODS: 858 adults from across the US meeting traditional guideline criteria for PA testing underwent testing. The influence of demographic factors on test result interpretations was assessed after multivariable adjustment. RESULTS: Mean age was 62±11 years, with 54.6% women, 14% Black, and 22.9% Hispanic. Independent of antihypertensive medications and clinical comorbidities, participants aged ≥70 years had 24% lower aldosterone (P<0.05), 48% lower renin activity (P<0.001), and trended toward higher aldosterone-to-renin ratio (52% higher; P=0.14), compared with those <50 years. Aldosterone levels were higher in women compared with men across the lifespan. Black participants had 81% higher aldosterone-to-renin ratio than White participants (P<0.001), primarily due to lower renin (P<0.005). These demographic factors influenced the ultimate PA testing interpretation: participants ≥70 years old had 19% higher odds of a positive test than those <50 years old (P=0.002), and Black participants had 22% higher odds of a positive test than White participants (P<0.001). CONCLUSIONS: In this large, diverse, nationwide sample, older and Black participants had higher aldosterone-to-renin ratio and higher odds of testing positive for PA, and women had higher aldosterone levels than men across the lifespan. With newly expanded indications for PA testing, a greater appreciation of the influence of demographic characteristics on PA test results will be required.