Primary aldosteronism in South Asia: insights from a tertiary outpatient cohort in Bangladesh.

Context: Primary aldosteronism (PA), the most common and potentially curable cause of secondary hypertension, remains under-investigated in the low- and middle-income countries (LMIC) of South Asia. Given the high population density in South Asia, including Bangladesh, the burden of PA is likely substantial. However, data on its prevalence are scarce. Objective: To determine the prevalence of PA among hypertensive patients attending an endocrine hypertension clinic at a tertiary hospital in Bangladesh. Methods: In this cross-sectional observational study, consecutive hypertensive patients with a plasma aldosterone-to-renin ratio (ARR) > 50 pmol/mIU underwent a seated saline suppression test (SST). PA was defined as a 4 h post-saline plasma aldosterone concentration (PAC) > 170 pmol/L. Participants with post-saline PAC ≤ 170 pmol/L were classified as non-PA. In the absence of adrenal vein sampling, subtyping was based on adrenal CT. Results: Of 365 screened patients (mean age 41.6 ± 12.8 years; 70.7% female), 218 (59.7%) had an ARR > 50 pmol/mIU. Of these, 207 completed the SST, with 114 (31.2% overall) meeting biochemical criteria for PA. Most participants with PA and non-PA were normokalemic, although hypokalemia was significantly more frequent in those with PA (27.7 vs 9.5%; P < 0.001). The majority of patients with PA had controlled office blood pressure on standard antihypertensive medications or stage 1 hypertension; 5.3% had resistant hypertension. Conclusion: PA appears highly prevalent among hypertensive patients in Bangladesh and often presents without classic features such as hypokalemia or resistant hypertension. These findings support recent guideline recommendations for broader PA screening in all individuals with hypertension to improve detection and cardiovascular outcomes.