Clinical biochemistry
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Clinical biochemistry · Jan 2009
Validation of a simple method of estimating plasma free cortisol: role of cortisol binding to albumin.
To develop, optimize, and validate a generalized mass action, equilibrium solution that incorporates measured concentrations of albumin as well as cortisol binding globulin (CBG) to estimate free cortisol. ⋯ Mass action solutions that incorporate the measured concentration of albumin as well as CBG provide a reasonably accurate estimate of free cortisol that generalizes to conditions of health as well as a setting of hypercortisolism and low CBG and albumin concentrations associated with septic shock. Modeling studies emphasize the significant contribution of albumin deficiency and albumin-bound cortisol under conditions of CBG-deficiency, and identify a synergistic effect by which combined CBG and albumin deficiency contribute to elevation of free cortisol in septic shock.