Afternoon serum cortisol level of 7 µg/dL or higher may serve as a diagnostic cutoff point to rule out hypocortisolemia

Abstract

Inadequate production of cortisol, known as hypocortisolemia, has been a challenging condition to diagnose, especially when it comes to adrenal insufficiency. Most practitioners utilize the morning serum cortisol levels when conducting screening processes. We investigate the clinical utility of using a cutoff point of 7 µg/dLon afternoon serum cortisol level for ruling out hypocortisolemia. Based on available patient records, those above this threshold may eliminate the concern of adrenal insufficiency due to the high sensitivity and specificity. Furthermore, this method is convenient compared to conventional stimulation tests for afternoon cortisol assessment. This is a new approach for initial screening that is non-invasive. Materials and methods:

The study included 60 patients exhibiting hypotension and fatigue. All participants underwent afternoon basal serum cortisol measurements, followed by an ACTH-stimulated cortisol test one hour post-injection.

Results: The results shows that basal afternoon cortisol of 7µg/dL or more can exclude hypercortisolemia and afternoon basal cortisol 7 µg/dL correspond to acth stimulated cortisol 18 mcg/dl as a cutoff value excluding hyporcortisolemia.

Conclusion: The data indicates that serum cortisol concentration exceeding 7 µg/dL in the afternoon can be used as reliable exclusion criteria in specimens collected from low risk individuals thereby eliminating the need for additional confirmatory tests. More in depth studies need to be done to refine diagnostic thresholds and make crucial clinical decisions better.