What is the relation between serum potassium and aldosterone?

It is well known that serum potassium levels come down with increased aldosterone secretion. That is because aldosterone causes potassium excretion and retention of sodium and water. In a reciprocal relationship, alterations in potassium concentrations directly affect aldosterone secretion independent of renin. Increase in plasma potassium stimulates aldosterone secretion. In a way it acts as a protective mechanism against hyperkalemia. On the other hand, hypokalemia inhibits aldosterone secretion [1].

It is interesting to note that aldosterone can be synthesized in tissues other than the adrenal cortex like the heart, blood vessels, kidneys and adipocytes. Plasma aldosterone levels correlate with body mass index and there is higher prevalence of hyperaldosteronism in obesity. Weight loss is associated with reduced aldosterone levels. Adipocytes have functionally active aldosterone synthase [2]. Adipocytes also produce components of the renin-angiotensin system like angiotensin II. Abdominal obesity predisposes to potassium depletion with diuretic therapy, possibly by these interactions [3].

References

1. Fioretti F, Testani JM, Tio MC, Pitt B, Butler J. Aldosterone and Aldosterone Modulation in Cardio-Kidney Diseases. J Am Coll Cardiol. 2025 Aug 5;86(5):354-373. doi: 10.1016/j.jacc.2025.06.012. PMID: 40738563.
2. Briones AM, Nguyen Dinh Cat A, Callera GE, Yogi A, Burger D, He Y, Corrêa JW, Gagnon AM, Gomez-Sanchez CE, Gomez-Sanchez EP, Sorisky A, Ooi TC, Ruzicka M, Burns KD, Touyz RM. Adipocytes produce aldosterone through calcineurin-dependent signaling pathways: implications in diabetes mellitus-associated obesity and vascular dysfunction. Hypertension. 2012 May;59(5):1069-78. doi: 10.1161/HYPERTENSIONAHA.111.190223. Epub 2012 Apr 9. PMID: 22493070.
3. Mariosa LS, Ribeiro-Filho FF, Batista MC, Hirota AH, Borges RL, Ribeiro AB, Zanella MT. Abdominal obesity is associated with potassium depletion and changes in glucose homeostasis during diuretic therapy. J Clin Hypertens (Greenwich). 2008 Jun;10(6):443-9. doi: 10.1111/j.1751-7176.2008.07817.x. PMID: 18550934; PMCID: PMC8109993.