Clinical implications for biochemical diagnostic thresholds of adrenal sufficiency using a highly specific cortisol immunoassay

Transition to a more specific cortisol assay requires revision of diagnostic thresholds for dynamic tests of adrenal insufficiency. With the Roche Cortisol II assay, a cut-off of 350 nmol/L should replace the traditional 500 nmol/L although some healthy subjects may be very close to this level.