The presentation and diagnosis of primary and secondary cortisol deficiency

The characteristic presentations of primary and secondary hypo cortisolism have been described based on the recorded prevalence of clinical features in these conditions. They emphasize chronic orthostatic hypotension and acute, stress induced hypotensive crises. Simultaneous plasma corticotropin and cortisol levels at 8.00 a.m. are often diagnostic. The rapid corticotropin test is unreliable in partial corticotropin deficiency states. When response to corticotropin is normal but pituitary insufficiency is possible, the overnight metyrapone or insulin-tolerance test is indicated. Response to corticotropin-releasing hormone administration is less conclusive, except after pituitary surgery. Effects of interleukin-6 on corticotropin and cortisol levels appear promising as a future stress test. Corticotropin and cortisol responses to corticotropin-releasing hormone plus lysine vasopressin were negatively correlated in 10 normal subjects, apparently revealing a genuine corticotroph phenotype in each individual. Extreme difficulty in ruling out corticotropin deficiency in severely stressed hypotensive patients results from the inability to estimate appropriate cortisol responses to varying degrees of stress, and this inability sometimes necessitates initial evaluation of clinical response to steroid therapy.