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A study into the use of an at-home test which uses saliva rather than blood to diagnose adrenal insufficiency, which has been developed by scientists at the University of ��«Ӱҵ with funding from the National Institute for Health and Care Research (NIHR), could reduce the number of hospital tests currently required by up to 70 per cent. 

Adrenal insufficiency is a common disorder of the adrenal glands, and occurs when the body is no longer able to make cortisol, a major hormone that helps the body overcome stress, infections and regulates body sugars, proteins and fats. This is particularly common in those who take oral steroids for other medical conditions as the body’s natural cortisol-making response shuts down while this function is temporarily taken over by the synthetic steroid. 

During the study over 200 patients attending ��«Ӱҵ Teaching Hospitals NHS Foundation Trust’s Endocrine Unit identified as being at risk of adrenal insufficiency due to long-term steroid use to treat other conditions were given swabs and a video showing them how to produce a saliva sample. The samples were taken in the morning at home, and the majority of patients reported they preferred this method to having to go to the hospital for a Short Synacthen Test (SST).  

The SST is an invasive screening procedure which requires patients to attend a one-hour appointment and have their bloods taken and measured once and then 30 minutes later following an injection of tetracosactrin, a diagnostic agent. The findings of the £205,000 National Institute for Health and Care Research study, published in NEJM Evidence, show that when this new method of screening was implemented 70 per cent of patient visits for diagnostic tests were prevented.  

The researchers estimate that this could reduce the number of SSTs undertaken for adrenal insufficiency diagnostic investigations across the whole of England from 92,000 visits per year to just 23,000. The saliva test method offers a range of benefits and is now being considered for roll out across the NHS and worldwide. Ultimately, the test is cheaper and should mean that diagnosis is more efficient.  

Professor Richard Ross, Professor of Endocrinology at the University of ��«Ӱҵ’s Department of Oncology and Metabolism, explains: “Cortisol is a vital stress hormone from the adrenal gland and cortisol deficiency, adrenal insufficiency, also called Addison’s Disease, can result in an adrenal crisis which if untreated can be life-threatening. A common cause is anti-inflammatory steroid treatment which is widely prescribed for conditions such as asthma, arthritis and inflammatory bowel disease. These people are at risk of adrenal insufficiency. The diagnosis is often made late as currently patients have to go to hospital for blood tests. 

“The new test checks for deficiency when people wake in the morning when there is a cortisol peak. Rather than tests that involve blood samples and an injection, the saliva test is proven to be as good as a blood test, and is more efficient.” 

Dr Miguel Debono, Consultant Endocrinologist at ��«Ӱҵ Teaching Hospitals NHS Foundation Trust and Honorary Senior Lecturer at the University of ��«Ӱҵ’s Department of Oncology and Metabolism, said: “Up to three per cent of the population take oral steroids to help with a broad range of inflammatory conditions, with around 50 per cent of these suffering with adrenal insufficiency.   

“Presently the tests used to make this diagnosis are complex and necessitate visits to hospital with long waiting times and testing is expensive. Roll out of waking salivary cortisone to clinical care will allow a more rapid diagnosis of adrenal insufficiency by a convenient, simple test which has been shown to be accurate and cheaper and can be carried out at home. This is highly advantageous to both patients and health care systems, so we are delighted to have worked in partnership with the University of ��«Ӱҵ on this important research.” 

Professor Marian Knight, Programme Director for NIHR's Research for Patient Benefit Programme, said, “This is a great example of NIHR-funded research that will bring immediate benefits to patients - giving them the option to do a simple saliva test at home instead of going to hospital for a blood test, to help spot people at risk of adrenal insufficiency.  

Karen Sherlock, 69, who lives in Matlock, and suffers with steroid treatment-induced adrenal insufficiency, believes that the new at-home saliva test could make a big difference to patients like her. 

“I developed adrenal insufficiency due to the steroids I was taking for a serious immune condition. I’ve had lots of support from the endocrine unit over the years, but my body may never produce enough of its own naturally occurring cortisol. If this saliva test had been available to me while I was having investigations, it would have meant I’d have avoided a 40-mile round trip to ��«Ӱҵ’s endocrine unit – a journey which I had to undertake every six months. It’s very simple to do, and it also avoids the need for an outpatient trip, saving staff and patient time.” 

Louise Smart, age 59, who lives in the Derbyshire Dales, agrees: 

“I was diagnosed with secondary adrenal insufficiency six years ago. At the start I was having to go to my GP or hospital for regular cortisol screening tests every six weeks, and this meant taking time out to travel to and from the hospital, and then spending at least half an hour at the appointment. Plus there’s the time spent waiting for the appointment to be booked too. The at-home saliva test was so much easier to do and saved time, a trip to the GP and endocrine appointment, so it’s been a win-win for me.”