<P> It has been suggested that this is due to abnormalities in the secretion of secretin in the brain and that "Secretin as a neurosecretory hormone from the posterior pituitary, therefore, could be the long - sought vasopressin independent mechanism to solve the riddle that has puzzled clinicians and physiologists for decades ." There are no abnormalities in total body sodium metabolism . Hyponatremia and inappropriately concentrated urine (U> 100 mOsm / L) are seen </P> <P> Diagnosis is based on clinical and laboratory findings of low serum osmolality and low serum sodium . </P> <P> Urinalysis reveals a highly concentrated urine with a high fractional excretion of sodium (high sodium urine content compared to the serum sodium). A suspected diagnosis is based on a serum sodium under 138 . A confirmed diagnosis has seven elements: 1) a decreased effective serum osmolality - <275 mOsm / kg of water; 2) urinary sodium concentration high - over 40 mEq / L with adequate dietary salt intake; 3) no recent diuretic usage; 4) no signs of ECF volume depletion or excess; 5) no signs of decreased arterial blood volume - cirrhosis, nehprosis, or congestive heart failure; 6) normal adrenal and thyroid function; and 7) no evidence of hyperglycemia (diabetes mellitus), hypertriglyceridemia, or hyperproteinia (myeloma). </P> <P> There are nine supplemental features: 1) a low BUN; 2) a low uric acid; 3) a normal creatinine; 4) failure to correct hyponatremia with IV normal saline; 5) successful correction of hyponatremia with fluid restriction; 6) a fractional sodium excretion> 1%; 7) a fractional urea excretion> 55%; 8) an abnormal water load test; and 9) an elevated plasma AVP . </P>

Diabetes mellitus is a disease associated with the inadequate secretion or action of adh