Which of the following laboratory studies or diagnostic procedures is most useful in identifying central diabetes insipidus (DI)?
A) Skull radiographs
B) Serum glucose level
C) Water deprivation test
D) Antidiuretic hormone (ADH) stimulation test

Question

Quizplus · Accepted Answer

Serum antidiuretic hormone ADH levels are compared with the blood and urine osmolality to differentiate syndrome of inappropriate antidiuretic hormone (SIADH)from central diabetes insipidus (DI).Increased ADH levels in the bloodstream compared with a low serum osmolality and elevated urine osmolality confirms the diagnosis of SIADH.Reduced levels of serum ADH in a patient with high serum osmolality, hypernatremia, and reduced urine concentration signal central DI.

Which of the Following Laboratory Studies or Diagnostic Procedures Is