Objective Markers and New Indicators in AI Disease (OMNI-AID Study)

Inclusion Criteria:

• Aged 18 - 85 years

• Male or female

• Participants who are otherwise healthy enough to participate, as determined bypre-study medical history and physical examination Patient groups only:

• Diagnosed with AI for over 6 months according to standard diagnostic criteria or witha medical condition requiring acute high dose steroid therapy for anti-inflammatorypurposes

• If diagnosed with AI, established on stable HC replacement or prednisolonereplacement, dose not altered for at least 3 months

• Established on a stable dose of Fludrocortisone, if taking, dose not altered for atleast 3 months

• Participants taking other hormone replacements (e.g. levothyroxine, testosterone orgrowth hormone in secondary adrenal insufficiency) are accepted providing that theirreplacement doses have not altered for at least 3 months

• Participants who are able and willing to give written informed consent to participatein the study.

Exclusion Criteria:

• Participants with a diagnosis of Type 1 or Type 2 diabetes mellitus.

• Unable to give informed consent.

• Excessive caffeine intake above 500 mg per day.

• Taking supplements or herbal medications that the participant is unwilling or unableto stop prior to and during the study period e.g. St John's Wort (may decreaseprednisolone levels), Cat's claw, Echinacea (immunomodulatory properties).

• Currently taking medications that alter CYP3A4 metabolism of glucocorticoids that theparticipant is unwilling or unable to stop prior to and during the study period e.g.phenytoin, phenobarbital, rifampicin, rifabutin, carbamazepine, primidone,aminogluethimide, itraconazole, ketoconazole, ciclosporin or ritonavir.

• Pregnancy, taking the oral contraceptive pill, or oral oestrogen replacement therapydue to the effects on cortisol binding globulin levels and determination ofprednisolone levels. Transdermal oestrogen replacement is permitted. Females ofchild-bearing age will be asked to provide a urine sample for a pregnancy test at eachvisit.

• Diagnosis of growth hormone deficiency, untreated

• History of any medical, psychological or other condition, or use of any medications,including over-the-counter products, which, in the opinion of the investigators, wouldeither interfere with the study.