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.

A Year of Saliva in Research

Posted by Dr. Alison McAllister on Friday, 23 December

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It’s always good to know that the work that ZRT has been doing for over 15 years in the field of salivary testing is still cutting edge and useful.  Today I just wanted to share a few of the studies using salivary estradiol that are being published in the literature. Just a hint, if you want to search for articles on salivary testing use pubmed.gov and search saliva estradiol (or progesterone, testosterone etc.). Be aware that salivary 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.

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Clearing up the Confusion about Reverse T3: Part 2. The Role of Reverse T3 in Thyroid Assessment

Posted by Margaret Groves on Friday, 08 May

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As more health care practitioners have understood the need to assess thyroid function based on what is going on at the cellular level, there has been an increasing demand for testing of reverse T3 (rT3), a hormone sometimes referred to as the “hibernation hormone.” However, there is also much confusion about how it fits into the picture of thyroid function, and controversy regarding whether or not there is a clinical utility for this test in patients suffering from thyroid imbalance symptoms.

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Clearing up Confusion about Reverse T3: Part 1. The Deiodinases and Thyroid Hormone Bioavailability

Posted by Margaret Groves on Monday, 04 May

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Thyroid hormones are essential for the normal metabolic functioning of all tissues in the body, and a wide array of symptoms are therefore associated with abnormalities in thyroid hormone production and activation. Even when apparently adequate amounts of thyroxine are produced by the thyroid gland, thyroid function is profoundly affected by anything that disrupts conversion of thyroxine (T4) to the active thyroid hormone, triiodothyronine (T3). This conversion takes place primarily at the cellular level within tissues; only 20% of circulating T3 is generated by conversion of T4 within the thyroid gland itself.

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New Research on Vitamin D Using Dried Blood Spot Testing

Posted by Margaret Groves on Thursday, 23 April

Vitamin DTwo vitamin D studies were published recently, both utilizing ZRT's testing in dried blood spot.

Dried blood spot samples are well suited for research applications because they are equivalent to serum but have the advantage of ease of sample collection, shipping, and storage, which doesn’t require any refrigeration or biohazard labeling.  Also, samples are easily identified by details that can simply be written on the outside flap of the collection cards, which require minimal freezer space for long-term storage of samples.

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