Vulto A, et al. - In primary adrenal insufficiency and secondary adrenal insufficiency patients, researchers sought to compare precursors of endogenous corticosteroid production. The study sample for this ancillary analysis of two different studies consisted of 20 patients with primary adrenal insufficiency and matched controls and 19 patients with secondary adrenal insufficiency. In a substantial percentage of patients with both primary and secondary adrenal insufficiency, production of adrenal corticosteroids will probably endure during treatment. This synthesis seems to be sensitive to the dose of hydrocortisone in patients with secondary adrenal insufficiency. The residual concentrations of corticosteroids, however, were quantitatively low, so its clinical value has not been determined.