Hyponatremia: a prospective analysis of its epidemiology and the pathogenetic role of vasopressin

Ann Intern Med. 1985 Feb;102(2):164-8. doi: 10.7326/0003-4819-102-2-164.


We prospectively evaluated the frequency, cause, and outcome of hyponatremia (plasma sodium concentration, less than 130 meq/L), as well as the hormonal response to this condition, in hospitalized patients. Daily incidence and prevalence of hyponatremia averaged 0.97% and 2.48%, respectively. Two thirds of all hyponatremia was hospital acquired. Normovolemic states (so-called syndrome of inappropriate secretion of antidiuretic hormone) were the most commonly seen clinical setting of hyponatremia. The fatality rate for hyponatremic patients was 60-fold that for patients without documented hyponatremia. Nonosmotic secretion of vasopressin was present in 97% of hyponatremic patients in whom it was sought. In edematous and hypovolemic patients, plasma hormonal responses (increases in plasma renin activity and aldosterone and norepinephrine levels) were compatible with baroreceptor-mediated release of vasopressin. Hyponatremia is a common hospital-acquired electrolyte disturbance that is an indicator of poor prognosis. Nonosmotic secretion of arginine vasopressin is a major pathogenetic factor in this electrolyte disturbance.

MeSH terms

  • Adolescent
  • Adult
  • Arginine Vasopressin / blood
  • Arginine Vasopressin / physiology*
  • Drinking
  • False Positive Reactions
  • Female
  • Hormones / blood
  • Humans
  • Hyperglycemia / complications
  • Hyponatremia / epidemiology*
  • Hyponatremia / etiology
  • Hyponatremia / mortality
  • Male
  • Middle Aged
  • Prospective Studies


  • Hormones
  • Arginine Vasopressin