Delayed Diagnosis, Greater Disease Burden: Primary Aldosteronism in a Brazilian Cohort

Background Primary aldosteronism (PA) is frequently underdiagnosed, resulting in prolonged exposure to aldosterone excess. In Brazilian cohorts, delayed diagnosis has been associated with high prevalence of hypokalemia, suggesting severe disease at presentation. We evaluated PA severity and its association with PA subtype using the Primary Aldosteronism Severity Classification (PASC). Methods PA patients were retrospectively evaluated over a 25-year period at a tertiary university hospital. Severity was classified using PASC, based on blood pressure, serum potassium, and plasma aldosterone. Kobayashi score was used to estimates the probability of bilateral PA. Outcomes were assessed by Primary Aldosteronism Surgical Outcome (PASO) and Primary Aldosteronism Medical Outcome (PAMO) criteria. Results Among 120 patients (56% female), 52 underwent unilateral adrenalectomy and 68 received medical therapy. Most diagnoses (84%) occurred in the past decade. Median ages were 32 years at hypertension onset and 53 years at PA diagnosis. Most patients presented hypokalemia (75%), more frequent in lateralized than bilateral PA (85% vs 66%; p = 0.03). Overall, 98% of patients had moderate or severe PASC, more common in lateralized than bilateral PA (61.5% vs 36.8%; p = 0.01). Severity correlated with aldosterone levels, hypokalemia, and antihypertensive medications (all p < 0.0001), but not with diagnostic delay. Higher Kobayashi score was associated with bilateral PA. Adrenalectomy resulted in high rates of biochemical success, while medically treated patients showed predominantly partial clinical improvement. Conclusions Brazilian patients with PA presented substantial diagnostic delay and predominantly moderate-to-severe disease. PASC and the Kobayashi score may complement subtype assessment when adrenal venous sampling is unavailable.