Urinary tetrahydroaldosterone and aldosterone-18-glucuronide excretion in white and black normal subjects and hypertensive patients

J Clin Endocrinol Metab. 1981 Feb;52(2):214-9. doi: 10.1210/jcem-52-2-214.


Urinary aldosterone excretion is commonly determined by assay of aldosterone liberated from the acid-labile metabolite, aldosterone-18-glucuronide (Aldo-18-G), which reflects 5-15% of aldosterone secretion. However, since 3alpha, 5beta-tetrahydroaldosterone (TH-Aldo), the major metabolite, reflects 15-40% of aldosterone excretion, determination of its excretion should usually provide a more accurate index of aldosterone secretion. We have validated a RIA for urinary TH-Aldo and compared its excretion in black and white normal subjects and patients with essential hypertension and primary aldosteronism during consumption of low, normal, and high sodium diets. Urinary TH-Aldo excretion averaged 4.5 +/- 2.0 (mean +/- SD) times that of Aldo-18-G. The ratio of excretion of the two remained relatively constant during low, normal, and high sodium diets. There was no difference in the excretion of TH-Aldo or Aldo-18-G in black vs. white normal subjects or hypertensive patients and no age-related changes in the excretion of either metabolite from 20-60 yr of age. Two of nine patients with primary aldosteronism had normal Also-18-G excretion but elevated TH-Aldo excretion. We conclude that determination of both metabolites increases the diagnostic accuracy for primary aldosteronism.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aldosterone / analogs & derivatives*
  • Aldosterone / urine
  • Black People*
  • Diet
  • Female
  • Glucuronates / urine
  • Humans
  • Hyperaldosteronism / urine*
  • Hypertension / urine*
  • Kinetics
  • Male
  • Middle Aged
  • Radioimmunoassay
  • Sodium / administration & dosage
  • White People*


  • Glucuronates
  • tetrahydroaldosterone
  • aldosterone 18-glucuronide
  • Aldosterone
  • Sodium