Salivary testing.

Testosterone is produced by the testes in men, and by the ovaries in women. Similarly to other steroid hormones, it follows a diurnal rhythm1,2peaking in the morning and declining during the day. The hormone exists in the blood in several forms, including free, bound to sex hormone-binding globulin (SHBG) or bound to albumin. Free testosterone is the biologically active form – meaning it can interact with androgen receptors in various tissues throughout the body – and is responsible for the physiological functions associated with the hormone.

The level of testosterone is assessed by measuring the free fraction, and can be performed in bodily fluids such as plasma, serum and saliva. Only free testosterone can make its way from the bloodstream into saliva, making the latter a good candidate for the testing. Using saliva to measure hormones is becoming increasingly popular, as this approach is less invasive and samples can be easily collected several times a day, even by patients themselves. This is important as, due to the diurnal rhythm of testosterone, both the collection time and number of samples play a role in the evaluation of peak and baseline testosterone levels.

Reliable results

Saliva-based testing is an important tool in monitoring testosterone levels in men, but obtaining reliable diagnoses requires assays that have high sensitivity and give accurate and reproducible results. Tecan has over 20 years of experience in manufacturing immunoassays for saliva hormone testing, and is known to offer assays of exceptional quality to support the growing saliva research and diagnostics community. The company’s luminescence- and ELISA-based saliva immunoassays are used around the world, and have been proven to accurately measure cortisol and sex hormones in various peer-reviewed studies.2,3Goncharov et al. measured salivary testosterone with the Tecan Testosterone Luminescence Immunoassay.2The study showed that this assay offered accurate measurements of salivary testosterone levels for diagnosis of different forms of hypogonadism in men, as well as for the evaluation of androgen status in women. Schmidt et al. came to similar conclusions when using the Testosterone Luminescence Immunoassay in healthy individuals, stating that the assay is suitable for the quantification of the steroid hormone in human saliva.3

Stress and testosterone

Stress can have a complex impact on testosterone levels. Acute stress, such as a sudden stressful event, can actually lead to a temporary increase in testosterone levels as part of our ‘fight or flight’ response, where various hormones are released to prepare the body for immediate action. However, chronic or prolonged stress can lead to a decrease in testosterone levels over time as the stress hormone cortisol – which is released in response to stress – can interfere with the production of testosterone. High cortisol levels inhibit the production of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which are necessary for the testes to produce testosterone. Additionally, chronic stress can lead to lifestyle changes that further contribute to decreased testosterone levels, such as poor sleep, unhealthy eating habits and reduced physical activity.

Physiological and psychological applications

Military personnel are required to work in challenging multi-stressor environments, which often include a combination of physical, psychological and cognitive demands, sleep loss, and caloric restriction. Avoiding burnouts and declines in performance requires stressful periods to be balanced with sufficient recovery, and it is important to establish metrics that would allow to evaluate training loads and rest in military training and operations. Cortisol and testosterone, as well as the testosterone/cortisol ratio have been successfully used as markers of excessive training stress, physiological strain and inadequate recovery in non-military settings.4,5,6 Several studies have therefore been dedicated to investigating the variations in testosterone and cortisol levels in saliva during different military training phases, and relied on Tecan assays, including the Testosterone Luminescence Immunoassay. The findings suggest that hormonal responses could serve as markers of physiological strain during military training and could be useful indicators of soldier readiness when integrated into a larger monitoring system.7,8 The results can also be useful outside of the military, outlining how acute and physiological challenges trigger hormonal responses.

Summary

Testosterone levels have a major impact on men’s health, and it is important to have accurate and reliable methods to measure this hormone. Saliva is ideal for testosterone screening, as only the biologically active form – free testosterone – is present. Tecan can offer a wide range of assays that can measure various hormones – including cortisol and testosterone – and have been specially developed and validated for saliva. These assays have been used by both researchers and clinicians around the world, becoming increasingly popular thanks to their accuracy and reproducibility. The company has also recently launched a newly Steroid Panel LC-MS Kit enabling the measurement of up to 18 steroids in parallel in serum samples.

More information.

To find out more or to see our full portfolio please visit:

www.ibl-international.com/complementary-medicine/saliva-diagnostics
www.tecan.com/the-power-of-saliva-diagnostics

* Product availability and regulatory status may vary across regions outside the EU depending on local country-specific registration. Consult with your Tecan associate for further information.