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CompletedNCT00851942Updated Aug 12, 2020

Determination of Method-specific Normal Cortisol and Adrenal Hormone Responses to the Short Synacthen Test

A Phase 4 interventional study of Synacthen (Tetracosactrin) in Healthy, Adrenal Insufficiency and Hypopituitarism, sponsored by Cardiff University. Completed at 1 site in United Kingdom. Open to participants aged 18 Years to 80 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2020-08-12.

Sponsored by Cardiff University · Phase 4, Interventional, and Diagnostic

Phase
Phase 4
Study type
Interventional
Enrollment
165
Allocation
Not applicable
Ages
18 Years to 80 Years
Sex
All
01

Study summary

Objectives:

To establish valid serum total cortisol and salivary cut-offs for use with the short Synacthen test in patients with normal CBG concentrations.

To investigate, using current assays, the effect of assay differences on the serum total cortisol cut-off.

To explore the performance of these cut-offs in groups of patients with suspected adrenal insufficiency and high and low serum CBG concentration.

Methodology: An ACTH test (250 micrograms iv ACTH1-24) will be undertaken in healthy volunteers, women taking an oestrogen-containing oral contraceptive pill (OCP), patients with adrenal insufficiency and patients with low serum albumin. Serum cortisol in the samples collected from healthy volunteers will be measured using GC-MS, Advia Centaur (Siemens), Architect (Abbott), Modular Analytics E170 (Roche), Immulite 2000 (Siemens) and Access (Beckman) automated immunoassays. The estimated lower reference limit for the 30 min cortisol response to ACTH, defined as the 2.5th percentile of log-transformed concentrations, will be determined in this healthy population and used as a cut-off in the patient groups studied.

Read the detailed description

Synacthen® is a synthetic analogue of ACTH which has been used since the 1960s to assess adrenal sufficiency. It is now well established as a first line test to investigate diseases of the hypothalamo-pituitary-adrenal axis and to assess adrenal function in patients on long-term corticosteroid therapy. Briefly, cortisol is measured before and after injection of 250 micrograms of Synacthen®. In a normal individual serum cortisol will rise to concentrations greater than an arbitrary value (typically 550 nmol/l) 30 minutes after administration of Synacthen®.

In 2004 the All Wales Clinical Biochemistry Audit group surveyed protocols for performing and interpreting short Synacthen® tests. This identified wide differences in practice within Wales. As a result standards were drawn up for performance of the test. It was noted that there was considerable variability or bias between cortisol immunoassays and that the cortisol cut-off chosen for interpretation of the short Synacthen® test should be method dependent.

Clark et al., in 1998 reported cortisol cut-offs following Synacthen® using 4 well established commercially available cortisol immunoassays. This study demonstrated considerable differences between the cortisol immunoassays used in clinical laboratories at the time. It was also apparent that there were differences in gender-related responses to Synacthen® although there was no dependence on age. In the 8 years since publication of this study there have been advances in formulation of cortisol immunoassays as well as the instrumentation used to perform analyses. At the University Hospital of Wales cortisol is currently assayed using the Bayer Centaur automated immunoassay analyser. This assay was not available at the time of the study by Clark et al.,. The investigators' current short Synacthen® test cut-offs therefore rely on historical reference ranges which have become outdated. A re-evaluation of the cortisol cut-off is required to ensure that patients are not incorrectly classified.

It has been long been recognised that oestrogens (including ethinyloestradiol prescribed in combined oral contraceptive pills) increase total (but not free) serum cortisol levels. The degree of increase is related to the dose used and is thought to be due to an elevation in cortisol binding globulin (CBG). However, no comparisons of total serum cortisol in response to Synacthen® have been performed between women taking oestrogens and those who are not. Knowledge of the salivary cortisol response may also be useful in patients with decreased serum CBG concentrations e.g. severe nephrotic syndrome in whom the serum cortisol response may be misleading. The investigators therefore plan to measure salivary cortisol as part of the investigators' study protocol to assess the response of free cortisol.

17 Hydroxyprogesterone (17OHP) is an intermediate in the biosynthesis of cortisol. Deficiency of 21-hydroxylase enzyme activity leads to an increased concentration of 17OHP in the peripheral circulation. The short Synacthen® test can be used to assist in diagnosis of mild cases of congenital adrenal hyperplasia. Current reference ranges are taken from the literature.

02

Conditions studied

  • Healthy
  • Adrenal Insufficiency
  • Hypopituitarism

Keywords

  • Volunteer
  • Hypoadrenalism
  • Hypopituitarism
  • Healthy volunteers
03

In context

Adrenal Insufficiency

136 studies on the registry are indexed under Adrenal Insufficiency; 27 are open to participants now.

This study's enrollment of 165 is above the median of 44 across 71 interventional studies indexed under Adrenal Insufficiency.

Browse Adrenal Insufficiency studies →

Lead sponsor

Cardiff University is the lead sponsor of 44 studies on the registry; 2 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 80 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Volunteers will be in self-proclaimed good health
  • Volunteers will be free of illness on the day of testing
  • Volunteers will not be taking drug therapy.
  • Patients will be free of intercurrent illness on the day of testing
  • Patients will have a confirmed diagnosis of hypoadrenalism or hypopituitarism

Exclusion criteria

Exclusion Criteria:

  • Is pregnant or lactating. Females of must have a negative pregnancy test before enrollment onto the study. Non-child bearing potential is defined as for at least 1 year, surgical sterilisation or hysterectomy at least three months before the start of the study,
  • Is using ,
  • has any significant intercurrent disease,
  • has a history of thyroid or other disease,
  • has a previous history of to Synacthen®,
  • has a previous history of asthma
  • has a history of allergic disorder
  • has any mental condition rendering the patient unable to understand the nature or possible consequences of the study, and/or evidence of an uncooperative attitude.
Terms in these criteria, in plain language(5)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Postmenopausal

Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

05

Study design

Phase
Phase 4
Primary purpose
Diagnostic
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
165 participants (actual)

Study arms

  • Experimental
    Synacthen 250 micrograms

    IV injection of 250 micrograms of Synacthen in 1m

    Drug: Synacthen (Tetracosactrin)

Interventions

06

What researchers measure

Primary outcomes

  1. The primary end-point of the study will be to establish method dependent cortisol cut offs for the normal response to Synacthen® using the 5th percentile.

    Time frame: Cortisol response at 30 minutes

Secondary outcomes

  1. Cortisol measurements by immunoassay will be compared with the GC-MS gold standard method for normal volunteers and patients with hypopituitarism and hypoadrenalism.

    Time frame: Cortisol response at 30 minutes

  2. Synacthen® responses in women taking ethinyloestradiol-containing contraceptive pills will be compared with those who are not.

    Time frame: Cortisol response at 30 minutes

  3. We will establish cut offs for the salivary cortisol response to Synacthen® in normal volunteers using the 5th percentile.

    Time frame: Cortisol response at 30 minutes

  4. We will establish a 17OHP cut off in response to Synacthen® in normal female volunteers using the 5th percentile.

    Time frame: 17OHP response at 60 minutes

07

Study locations

1 site
  • Clinical Research Facility, University Hospital of Wales
    Cardiff, South Glamorgan CF14 4XW, United Kingdom
08

References and documents

Publications

  • Owen LJ, Adaway JE, Davies S, Neale S, El-Farhan N, Ducroq D, Evans C, Rees DA, MacKenzie F, Keevil BG. Development of a rapid assay for the analysis of serum cortisol and its implementation into a routine service laboratory. Ann Clin Biochem. 2013 Jul;50(Pt 4):345-52. doi: 10.1177/0004563212473448. Epub 2013 Jun 12. PubMed 23761380 ↗
09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 12, 2020, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT00851942
Lead sponsor
Cardiff University
Responsible party
Sponsor
First posted
Feb 26, 2009
Start date
Sep 2008
Primary completion
Jul 28, 2012
Completion
Jan 31, 2013
Last update
Aug 12, 2020

Study contacts

Aled Rees, MB BCh, PhD
principal investigator · Cardiff University

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

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