Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (1017 page)

Increased In

   Inhibin A: elevated during normal pregnancy

   Preeclampsia, Down syndrome, and some cancers

   Seventy percent of patients with granulose cell tumors

   Twenty percent of patients with epithelial ovarian tumors

Decreased In

   Ovarian aging

   Limitations

   Inhibin levels fluctuate during menstrual cycle.

INSULIN

   Definition

   This peptide hormone is enzymatically processed from proinsulin in pancreatic secretory granules of beta cells. Approximately 50% is removed from the blood during initial passage through the liver. Its half-life is 4–9 minutes. Secretion is regulated primarily by blood glucose levels; therefore, it should always be measured with concomitant blood glucose. Insulin deficiency is the crucial factor in the pathogenesis of type 1 DM.

   
Normal range:
6–27 μIU/mL.

   Use

   Diagnosis of insulinoma

   Diagnosis of fasting hypoglycemia