The ZRT Laboratory Blog

The ZRT Blog is an extensive resource for patients and health care providers searching for health and hormone testing information. Here, you can read about ZRT’s cutting edge research, advances in testing, wellness advice, and health industry highlights.

Avoiding 3 Common Interpretation Pitfalls for Salivary Cortisol Tests

Posted by Dr. Allison Smith on Tuesday, 08 August

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One of ZRT's most popular tests includes diurnal assessment of a patient's salivary cortisol levels. On the surface, these tests seem easy enough to interpret, but experienced clinicians know there can sometimes be pitfalls.

Patients testing cortisol in a clinical setting may take undisclosed medications, live under stressful conditions, have inflammation, genetic variations, tumors, and diseases. Sleuthing out the cause of cortisol elevations and depressions can be a real challenge.

To avoid unnecessary work-ups, there are a few areas to consider when interpreting a salivary cortisol test – Contamination, Suppression, and Comorbidities.

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A Year of Saliva Testing in Research

Posted by Dr. Alison McAllister on Friday, 23 December

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I wanted to share a few of the studies using saliva testing that were published in the literature in 2016.

Just a hint, if you want to search for articles on saliva testing, use pubmed.gov and search saliva estradiol (or progesterone, testosterone etc.).

Be aware that saliva hormone testing is so standard in the research world that rarely is it mentioned in the titles of the papers. Over 310 studies were published in 2016 using saliva testing – 61 studies for testosterone and 189 studies on cortisol, while poor progesterone was neglected with only 14 studies this last year.

It’s always good to know that the work that ZRT has been doing for almost 20 years in the field of saliva testing is still cutting edge and useful. 

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Celebrating ZRT's Hormone Laboratory Professionals

Posted by Dr. Sherry LaBeck on Friday, 29 April

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It may come as a surprise to most people that each year, the last full week of April is dedicated to recognizing and celebrating laboratory professionals.

This year Medical Laboratory Professionals Week falls on April 24-30. Setting aside one week a year to acknowledge these experts is a perfect opportunity to increase public awareness of, and appreciation for, clinical laboratory personnel. 

Just who are these hormone laboratory professionals? They are the skilled individuals whose expertise is vital to laboratory testing. At ZRT, state-of-the-art testing equipment is the norm and each instrument has an experienced specialist or team of specialists at the controls.

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How to Use the Cortisol Awakening Response (CAR) in Addressing Adrenal Function

Posted by Dr. Allison Smith on Friday, 04 March

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Treatment Takeaway

On awakening cortisol should increase about 50% in the first 30 minutes then begin to progressively drop the remainder of the day. Three, rather than one, early morning collections are what is needed to accurately assess the CAR; one immediately on waking, one 30 minutes later, and another at 1 hour.

Diurnal Rhythm Assessment

Thirty minutes after awakening from a good night's sleep, cortisol levels are at the highest they'll be all day. Following the morning peak, cortisol levels then fall to less than half that peak level by noon. They continue to drop to very low levels at night where they stay low during the sleep hours. Some individuals have a sharp rise to reach morning levels, others a more gradual incline. Looking at cortisol levels graphed during the day, any abnormal elevation, or depression of levels, or a loss of the expected curve with its characteristic morning peak and swooping decline towards evening may suggest HPA axis dysfunction – which is what we're most interested in assessing when we're looking at a 4-point salivary cortisol test.

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