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Trial registered on ANZCTR


Registration number
ACTRN12611001067965
Ethics application status
Approved
Date submitted
11/10/2011
Date registered
13/10/2011
Date last updated
8/04/2014
Type of registration
Prospectively registered

Titles & IDs
Public title
Assessment of the effect of single dose dexamethasone on the hypothalamic-pituitary axis
Scientific title
Double-blind randomised controlled trial assessing the effects of dexamethasone on the hypothalamic-pituitary-adrenal axis in healthy volunteers
Secondary ID [1] 273201 0
Nil
Universal Trial Number (UTN)
U1111-1125-1949
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
hypothalamic-pituitary axis suppression 278956 0
postoperative nausea and vomiting 278957 0
Condition category
Condition code
Metabolic and Endocrine 279135 279135 0 0
Normal metabolism and endocrine development and function
Anaesthesiology 279136 279136 0 0
Other anaesthesiology

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Double blind randomised controlled trial assessing the effects of a single dose of 8mg dexamethasone intravenously versus saline control on hypothalamic-pituitary axis suppression in healthy volunteers.
Intervention code [1] 269534 0
Treatment: Drugs
Comparator / control treatment
Saline control.
Crossover design
Minimum four week washout period between interventions
Control group
Placebo

Outcomes
Primary outcome [1] 279782 0
Percent cortisol suppression based on 0800hr plasma cortisol measurement pre- and 23-hours post-dexamethasone. Samples for cortisol obtained by blood collection.
Timepoint [1] 279782 0
23 hours post-dexamethasone administration
Secondary outcome [1] 294418 0
Percent reduction in Synacthen-stimulated plasma cortisol levels obtained by blood collection.
Synacthen testing will be performed pre-dexamethasone and at 24 hours post-dexamethasone administration
Timepoint [1] 294418 0
24 hours post-dexamethasone administration
Secondary outcome [2] 294419 0
Percent reduction in thyroid hormone levels. Thyroid hormone levels will be measured by blood analysis.
Timepoint [2] 294419 0
24 hours post-dexamethasone administration
Secondary outcome [3] 294420 0
Percent reduction in gonadal hormones. Gonadal hormones will be measured by blood analysis.
Timepoint [3] 294420 0
24 hours post-dexamethasone administration
Secondary outcome [4] 294421 0
Duration of cortisol suppression. Plasma cortisol will be measured by blood analysis.
Timepoint [4] 294421 0
24 hours, 48 hours, 72 hours, 96 hours post dexamethasone administration

Eligibility
Key inclusion criteria
Healthy male volunteers
Minimum age
18 Years
Maximum age
40 Years
Gender
Males
Can healthy volunteers participate?
Yes
Key exclusion criteria
Glucocorticoid use within the past 6 months
Psychiatric illness
Uncontrolled hypertension
Diabetes mellitus
Shift workers
Unable to give informed consent
Medications likely to interfere with dexamethasone metabolism
Hypothalamic-pituitary target organ axis disease
Acute illness

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation concealment
Opaque envelopes
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using computerised sequence generation
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Phase 4
Type of endpoint(s)
Pharmacodynamics
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 3907 0
New Zealand
State/province [1] 3907 0
Waikato

Funding & Sponsors
Funding source category [1] 270027 0
Charities/Societies/Foundations
Name [1] 270027 0
Kudos Award. Hamilton Science Excellence Awards. Presented by Hamilton Science Awards Trust
Address [1] 270027 0
Hamilton Science Awards Trust
PO Box 9512
Waikato Mail Centre
Hamilton 3240
Waikato
Country [1] 270027 0
New Zealand
Funding source category [2] 270028 0
Hospital
Name [2] 270028 0
Department of Endocrinology
Address [2] 270028 0
Waikato Hospital
Pembroke Street
Private Bag 3200
Hamilton 3240
Waikato
Country [2] 270028 0
New Zealand
Primary sponsor type
Individual
Name
Dr Marianne Elston
Address
Department of Endocrinology
Waikato Hospital
Private Bag 3200
Hamilton 3240
Waikato
Country
New Zealand
Secondary sponsor category [1] 269002 0
Individual
Name [1] 269002 0
Mr Goswin Meyer-Rochow
Address [1] 269002 0
Department of Surgery
University of Auckland
Waikato Hospital
Private Bag 3200
Hamilton 3240
Waikato
Country [1] 269002 0
New Zealand
Other collaborator category [1] 252292 0
Individual
Name [1] 252292 0
Associate Professor John V Conaglen
Address [1] 252292 0
Department of Endocrinology
Waikato Hospital
Private Bag 3200
Hamilton 3240
Waikato
Country [1] 252292 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 271984 0
Northern Y regional ethics committee
Ethics committee address [1] 271984 0
C/- Ministry of Health
130 Grantham Street
Hamilton 3240
Ethics committee country [1] 271984 0
New Zealand
Date submitted for ethics approval [1] 271984 0
Approval date [1] 271984 0
29/08/2011
Ethics approval number [1] 271984 0
NTY/11/05/050

Summary
Brief summary
Our adrenal glands produce cortisol which is our body’s natural “stress hormone”. Cortisol production is controlled by the hypothalamus and pituitary glands in the brain (hypothalamic-pituitary adrenal axis). This involves a feedback loop to prevent over- or under-production of cortisol.
Dexamethasone (a synthetic form of cortisol) has been shown to significantly reduce postoperative nausea and vomiting. Currently most patients having a general anaesthetic receive a single 8mg dose of dexamethasone. This has been studied in relation to a number of different surgery types and in adults appears to be safe and effective.
Dexamethasone has a long duration of action, typically quoted to be 36-72hours although the plasma half-life of dexamethasone is shorter at approximately 6 hours. Dexamethasone is used by endocrinologists to assess whether there is cortisol overproduction i.e. “dexamethasone suppression test” as it doesn’t interfere with the laboratory measurement of cortisol. Similar to the overnight dexamethasone suppression test it has been shown that after a single 8mg dose cortisol suppression occurs. What isn't known is how long the cortisol suppression lasts and whether other pituitary hormone levels are also suppressed.
Trial website
Trial related presentations / publications
Elston MS, Conaglen HM, Hughes C, Tamatea JA, Meyer-Rochow GY, Conaglen JV.
Duration of cortisol suppression following a single dose of dexamethasone in healthy volunteers: a randomised double-blind placebo-controlled trial. Anaesth Intensive Care. 2013 Sep;41(5):596-601. PubMed PMID: 23977910.
Public notes

Contacts
Principal investigator
Name 33263 0
Dr Marianne Elston
Address 33263 0
Department of Endocrinology
Waikato Hospital
Private Bag 3200
Hamilton 3240
New Zealand
Country 33263 0
New Zealand
Phone 33263 0
6478398899
Fax 33263 0
Email 33263 0
Marianne.Elston@waikatodhb.health.nz
Contact person for public queries
Name 16510 0
Dr Dr Marianne Elston
Address 16510 0
Department of Endocrinology
Waikato Hospital
Private Bag 3200
Hamilton 3240
Country 16510 0
New Zealand
Phone 16510 0
+6478398914
Fax 16510 0
Email 16510 0
Marianne.Elston@waikatodhb.health.nz
Contact person for scientific queries
Name 7438 0
Dr Dr Marianne Elston
Address 7438 0
Department of Endocrinology
Waikato Hospital
Private Bag 3200
Hamilton 3240
Country 7438 0
New Zealand
Phone 7438 0
+6478398914
Fax 7438 0
Email 7438 0
Marianne.Elston@waikatodhb.health.nz

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary