Figure 3.

Novel diagnostic flowchart adrenal insufficiency. When a physician suspects AI in a given patient, an early morning plasma cortisol measurement will be performed. Concentrations above an assay-specific cut-off level (e.g. 550 nmol/L for cortisol I and 420 nmol/L for cortisol II) rule out AI. Below this cut-off level, a salivary cortisol measurement could be performed to select patients for an ACTH stimulation test. Early morning salivary cortisol concentrations >5.9 nmol/L can rule out AI. Peak plasma or salivary cortisol concentrations after stimulation make up the diagnosis.