Severe Hyponatremia Caused by Hypothalamic Adrenal Insufficiency.

Abstract

A 60-year-old womanwas admitted with severe hyponatremia. Basal values of adrenocorticotropic hormone (ACTH), thyroid hormone and cortisol were normal on admission. Impairment of water diuresis was observed by water loading test. Initially, we diagnosed her condition as the syndrome of inappropriate secretion of antidiuretic hormone(SIADH). By provocation test, we finally confirmed that the hyponatremia was caused by hypothalamic adrenal insufficiency. The basal values ofACTHand cortisol might not be sufficient to exclude the possibility of adrenal insufficiency. Therefore, it is necessary to evaluate adrenal function by provocation test or to re-evaluate it after recovery from hyponatremia. (Internal Medicine 38: 426-432, 1999)

A case of primary adrenal diffuse large B cell lymphoma presenting with severe hyponatremia

“…Shibata et al [14] reported a similar case with severe hyponatremia in which the basal serum cortisol level was 12.1 lg/dL. The patient's hyponatremia fulfilled the criteria of SIADH used in Japan, but was normalized by the administration of hydrocortisone.…”

Recurrent Hyponatremia as Presenting Manifestation of Pituitary Macroadenoma

“…Cortisol being an inhibitor of ADH secretion, hence low level of cortisol leads to increased ADH secretion and resulting in decreased excretion of water by the kidney and subsequently causing hyponatremia [6]. It has also been shown that loss of suppression of the osmostat for ADH release could be the underlying mechanism for ADH hypersecretion in adrenal insuffi ciency [7]. Thus, the benefi t of corticosteroid replacement is thought to be mainly due to suppression of ADH.…”

The Role of Antidiuretic Hormone in Hyponatremia in Adrenal Insufficiency-Is the Guideline for the Diagnosis of Syndrome of Inappropriate Secretion of the Antidiuretic Hormone Appropriate?-

“…Serum arginine vasopressin (AVP) was inappropriately high in relation to low serum osmolality in these patients. Shibata et al (7) confirmed that the ADHsecretion increased inappropriately to osmolality and the osmotic threshold of ADHsecretion increased after glucocorticoid administration in their patient with adrenal insufficiency due to hypothalamic dysfunction who was initially diagnosed as SIADHin this issue of Internal Medicine.…”