Endocrine Abstracts

The Endocrine Society Guidelines 2016 recommend the Aldosterone Renin Ratio (ARR) to screen for Primary Hyperaldosteronism (PHA), yet we perceive low rates of referral to our service for such patients. Here we report a retrospective audit of ARR measurements requested through Regional Hospital Mullingar 01/01/2023 – 31/12/2023. ARR results were obtained directly from the referral laboratory. An assay specific ARR threshold >25 (ARR+) indicates possible PHA. We reviewed patient records for all ARR+ patients. A unified Excel database, including 144 consecutive ARR measurements from 139 patients, was created and interrogated using basic functions. Mean (± standard deviation) patient age was 45.9 (±15.7) years, 67/139 (48.2%) were female. Most ARR requests originated from secondary care (110/144, 76.4%). ARR+ was observed in 34/144 (23.6%) of samples, representing 34 unique patients. The indication for testing was evident for 19/34 (55.9%) ARR+ patients; resistant hypertension (9/19, 47.36%), early onset hypertension (6/19, 31.57%), adrenal adenoma (3/19, 15.78%) and hypokalaemia (1/19, 5.26%). Simultaneous serum potassium measurement was available for only 111/144 (77.1%) ARR measurements, with concomitant hypokalaemia observed in 6/144 (4.2%) instances. Medication records were available for 18/34 ARR+ patients with concomitant interfering Anti-Hypertensive therapy noted in 11/18 (61.1%) measurements, including 5/18 (27.8%) and 1/18 (5.6%) measurements on Beta Blockers and Spironolactone respectively. Only 8/34 (23.5%) ARR+ patients had attended the Endocrinology service. In total, these data indicate low rates of referral for ARR+ patients, high rates of ARR measurement on interfering medications, and suboptimal correction of hypokalaemia prior to testing. Twenty-six ARR+ patients have been identified for early assessment in the Endocrinology Clinic. These data will be disseminated to service users in both primary and secondary care. Going forward we will circulate to memorandum to service users advising of the assay specific ARR reference range and offering guidance regarding confounding by Anti-Hypertensive Medications and Hypokalaemia.