Prospective evaluation of a telmisartan suppression test as a diagnostic tool for primary hyperaldosteronism in cats

Abstract

AbstractBackgroundIn a previous study, telmisartan suppressed aldosterone secretion in healthy cats but not in cats with primary hyperaldosteronism (PHA).HypothesesTelmisartan suppresses aldosterone secretion in middle‐aged healthy cat and cats with diseases that may result in secondary hyperaldosteronism, but not in those with PHA.AnimalsThirty‐eight cats: 5 with PHA; 16 with chronic kidney disease (CKD), subclassified as hypertensive (CKD‐H) or non‐hypertensive (CKD‐NH); 9 with hyperthyroidism (HTH); 2 with idiopathic systemic arterial hypertension (ISH); and 6 healthy middle‐aged cats.MethodsProspective, cross‐sectional study. Serum aldosterone concentration, potassium concentration, and systolic blood pressure were measured before and 1 and 1.5 hours after PO administration of 2 mg/kg of telmisartan. The aldosterone variation rate (AVR) was calculated for each cat.ResultsNo significant difference in the minimum AVR was observed among groups (median [quartile 1 (Q1); quartile 3 (Q3)]: 25 [0; 30]; 5 [−27; −75]; 10 [−6; −95]; 53 [19; 86]; 29 [5; 78]) for PHA, CKD, HTH, ISH, and healthy cats, respectively (P = .05). Basal serum aldosterone concentration (pmol/L) was significantly higher in PHA cats (median [Q1; Q3]: 2914 [2789; 4600]) than in CKD‐H cats (median [Q1; Q3]: 239 [189; 577], corrected P value = .003) and CKD‐NH cats (median [Q1; Q3]: 353 [136; 1371], corrected P value = .004).Conclusions and Clinical ImportanceThe oral telmisartan suppression test using a single dose of 2 mg/kg telmisartan did not discriminate cats with PHA from healthy middle‐aged cats or cats with diseases that may result in secondary hyperaldosteronism.