Corticosteroid therapy may induce glucose intolerance by reducing the utilization of glucose in tissues and increasing hepatic glucose output. Diabetes mellitus requiring diet modifications and hypoglycemic agents has developed in some patients.
Adrenal suppression can persist for up to twelve months after long-term corticosteroid therapy. Giving corticosteroids once a day or once every other day may reduce adrenal suppression. After corticosteroid therapy has been tapered, supplemental corticosteroid therapy during times of physical stress may be required. [ Ref ]
Variability in cortisol assays creates an additional problem with setting criteria for a normal response to ACTH that apply to all centers. Two studies comparing cortisol results obtained with different assays showed a positive bias of radioimmunoassays and immunofluorometric enzyme assays of 10 to 50 percent compared with a reference value obtained using isotope dilution gas chromatography-mass spectrometry. As a result, in one study, depending on the combination of assay and criterion used, between 0 and 100 percent of healthy volunteers would be considered to have a normal response to ACTH. This illustrates the difficulty of interpreting cortisol responses that are close to the cutoff point. (3)