Life-threatening hypokalaemia on a low-carbohydrate diet associated with previously undiagnosed primary hyperaldosteronism [corrected]

Diabet Med. 2005 Nov;22(11):1605-7. doi: 10.1111/j.1464-5491.2005.01714.x.


Background: Low-carbohydrate diets are popular and fashionable for weight loss despite lack of evidence about long-term effects. Many individuals attempting to lose weight have hypertension, especially those with diabetes, and the prevalence of hyperaldosteronism among hypertensive patients is higher than previously recognized. We present a patient with Type 2 diabetes and previously undiagnosed hyperaldosteronism who developed life-threatening hypokalaemia while following a low-carbohydrate diet.

Case report: A 60-year-old man with diet-treated Type 2 diabetes and hypertension presented with generalized muscle weakness and serum potassium of 1.9 mmol/l. He had succeeded in losing three and a half stones during the previous 4 months by adhering strictly to a low-carbohydrate diet. HbA(1c) was 4.8% and plasma aldosterone:renin ratios were elevated suggestive of increased aldosterone secretion. On a low-calorie mixed diet serum potassium levels were maintained in the low-normal range over the following 165 days. The adrenals were normal on CT scanning and blood pressure responded dramatically to the addition of spironolactone on day 212 (125/83 mmHg).

Conclusions: The prevalence of primary hyperaldosteronism in the hypertensive population, based on elevation of plasma renin:aldosterone ratio, is approximately 6%. The majority of these people are normokalaemic and remain undiagnosed. However, when carbohydrate intake is restricted such individuals are at increased risk of potentially life-threatening metabolic derangements.

Publication types

  • Case Reports

MeSH terms

  • Aldosterone / blood*
  • Diabetes Mellitus, Type 2 / complications*
  • Diet, Reducing / adverse effects*
  • Dietary Carbohydrates / adverse effects*
  • Humans
  • Hypoaldosteronism / blood
  • Hypoaldosteronism / drug therapy
  • Hypoaldosteronism / etiology*
  • Hypokalemia / drug therapy
  • Hypokalemia / etiology*
  • Male
  • Middle Aged
  • Mineralocorticoid Receptor Antagonists / therapeutic use
  • Renin / blood
  • Spironolactone / therapeutic use
  • Treatment Outcome


  • Dietary Carbohydrates
  • Mineralocorticoid Receptor Antagonists
  • Spironolactone
  • Aldosterone
  • Renin