Kobayashi H, et al. - Given that primary aldosteronism induces renal structural damage following glomerular hyperfiltration, and an acute decline in estimated glomerular filtration rate (eGFR) results from primary aldosteronism-specific treatment, researchers examined a retrospective cohort from the multicenter Japan Primary Aldosteronism Study in order to find out if this change influenced the long-term eGFR slope. Based on treatment history, patients with primary aldosteronism were assigned to the adrenalectomy (n = 202) and mineralocorticoid receptor (MR) antagonist (n = 303) groups. A large initial eGFR fall in both groups was independently predicted by increased age, low serum potassium levels, high eGFR, and high plasma aldosterone levels. Findings revealed that the smaller the acute decline in eGFR by the start of MR antagonists, the greater the rate of long-term eGFR decline. Although this treatment-induced acute fall in eGFR is sometimes a clinical concern, the favorable implications of the acute fall concerning long-term renal outcomes were highlighted.