Current glucocorticoid replacement regimens, in adrenal insufficiency, fail to mimic the physiological cortisol secretion, thereby fostering serious side effects.
Aim: To experimentally evaluate the impact of CpG methylation within the FKBP5 gene as a possible short- and long-term marker for cortisol exposure in humans.
Materials & methods: An ACTH-stimulation test was carried out and methylation status of the FKBP5 gene in leukocytes was determined.
Results: A negative correlation between basal levels of methylation and serum cortisol was observed. Individual changes in FKBP5 methylation after 24 h correlated with cortisol responses.
Conclusion: Considering previous studies conducted with murine leucocytes, FKBP5 methylation may be suitable as a long-term biomarker, rather than acute glucocorticoid exposure, also in humans.
Keywords: ACTH stimulation test; FKBP5; demethylation; glucocorticoid exposure; hydrocortisone.