[Hyporeninemic hypoaldosteronism. Case report and attempt at pathophysiological classification (author's transl)]

Area of Science:

• Endocrinology
• Nephrology

Background:

• Hypoaldosteronism, an isolated aldosterone deficiency, is a rare endocrine disorder.
• It is distinct from combined deficiencies of cortisol and aldosterone or enzyme deficits affecting both mineralocorticoid and glucocorticoid synthesis.

Observation:

• A 75-year-old male presented with hyperkalemia, moderate renal insufficiency, low basal aldosterone and renin levels, and normal glucocorticoid function.
• Hormonal evaluation revealed a subnormal response to stimuli like walking and saline depletion.

Findings:

• Hyperkalemia was effectively managed with fluorocortisone administration.
• The case illustrates isolated hypoaldosteronism, classified by renin levels (low, normal, or high).

Implications:

• A high index of suspicion is crucial for diagnosing unexplained hyperkalemia.
• Prompt diagnostic testing can confirm or exclude hypoaldosteronism, enabling appropriate treatment.