title: Hyponatremia: a prospective analysis of its epidemiology and the pathogenetic role of vasopressin.
abstract: 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: D000293:Adolescent; D000328:Adult; D001127:Arginine Vasopressin / Q000097:blood / Q000502:physiology*; D004326:Drinking; D005189:False Positive Reactions; D005260:Female; D006728:Hormones / Q000097:blood; D006801:Humans; D006943:Hyperglycemia / Q000150:complications; D007010:Hyponatremia / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D006728:Hormones; D001127:Arginine Vasopressin