Pulsed glucocorticoid therapy successfully replaced physiological cortisol
CHICAGO — Through a pulsed subcutaneous regimen, physiological circadian and ultradian cortisol were successfully replaced, according to research presented at the joint meeting of the International Congress of Endocrinology and the Endocrine Society.
“We are in a position to reproduce a more physiological looking cortisol, circadian and ultradian rhythms,” Georgina M Russell, MBBC, MRCP, PhD, of the University of Bristol, United Kingdom, said during her presentation.
Russell and fellow researchers tested the novel pulsed hydrocortisone therapy, delivered via a portable infusion pump, in 22 healthy volunteers.
Participants underwent dexamethasone suppression (2 mg daily), then received hydrocortisone subcutaneously as two individual pulses of secretion; doses were high, medium or low in size.
Over the course of 7 hours, a human automated blood sampling system collected samples in intervals of 10 minutes for cortisol and 1 hour for adrenocorticotropic hormone (to confirm endogenous adrenal suppression). Size and frequency of doses were adjusted to meet physiological blood levels of cortisol.
For a further pilot study, participants received dexamethasone (4 mg daily) to inhibit endogenous hypothalamo-pituitary-adrenocortical activity, with subcutaneous hydrocortisone infused via pump in eight pulses — three high, three medium and two low. Blood samples were taken at corresponding times, but over 24 hours. This produced a circadian cortisol peak of ≥500 nmol/L with a trough of ≤100 nmol/L; a definitive “on/off” period was observed between individual pulses.
“Perhaps now we can use this tool to be able to assess what a more optimal dose would be for our patients,” Russell said, “and use it as a tool to assess cognitive, metabolic and cardiovascular and immunological importance of normal physiological patterns of cortisol in patients on steroid replacement.” — by Allegra Tiver
For More Information: Russell GM. Abstract OR48-1. Presented at: The joint meeting of the International Congress of Endocrinology and the Endocrine Society; June 21-24, 2014; Chicago.
Disclosures: Russell reports no relevant disclosures.