Tuesday, 19 July 2016

Mid Year Research Summary, Professor Douglas Granger Founder and Chief Scientific & Strategy Advisor to Salimetrics












Link to UCI Institute for Interdisciplinary Salivary Bioscience Research


An update from our founder - Prof. Doug Granger's
publications coming soon in 2016!
 

Liu, Y., Granger, D. A., Klein, L. C., Almeida, D. M., & Zarit, S. H. (minor revisions). Diurnal salivary alpha-amylase dynamics among dementia family caregivers: daily stress and adult day services use. Health Psychology

Kornienko, O., Schaefer, D. R., & Granger, D. A. (accepted minor revisions). Social networks, stress hormones, and Adolescent Development. In Hopcroft, R. (Ed), Oxford Handbook of Evolution, Biology, and Society. Oxford University Press.

Hutchinson, C., Laporta, A. J., Moloff, A., Lea, M., Ketchum, R., Franciose, R., Alson, R., Czekajlo, M., Lavell, K., Markham, S. Field, R. D., Hoang, T. N., & Granger, D.A. (minor revisions). Salivary cortisol and alpha-amylase response to hyper-realistic emergency trauma simulation in military medical students. Journal of Surgical Education.

Buckingham-Howes, S., Mazza, D, Wang, Y., Granger, D. A., & Black, M. (in press). Prenatal drug exposure and adolescent cortisol reactivity: association with behavioral concerns. Journal of Developmental & Behavioral Pediatrics.

Exum, N. G., Pisanic, N., Granger, D. A., Schwab, K. J., Detrick, B., Kosek, M., Egorov, A. I., Griffin, S. M., & Heaney, C. D. (in press). Use and application of biomarkers to estimate waterborne infections. Current Environmental Health Reports.

Berry, D., Blair, C., Willoughby, M., Raver, C., Granger, D. A., Mills-Koonce, R., & the Family Life Project key Investigators (in press). Maternal sensitivity and adrenocortical functioning across infancy and toddlerhood: Physiological adaptation to context? Development and Psychopathology PMID 27065311

Lucas-Thompson, R., Lunkenheimer, E., & Granger, D. A. (in press). Adolescents conflict appraisals moderate the link between marital conflict and physiological stress reacitivity. Journal of Research on Adolescence.

Stroud, C. B., Chen, F. R., Doane, L. D. & Granger, D. A. (in press). Individual Differences in Early Adolescents’ Latent Trait Cortisol (LTC): Relation to early adversity. Developmental Psychobiology PMID 26990202


Finegood, E. D., Blair, C., Granger, D. A., Hibel, L. C., Mills-Koonce, R., & The Family Life Project Investigators. (in press). Psychobiological influences on maternal sensitivity in the context of adversity. Developmental Psychology


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Tuesday, 12 July 2016

Better Together - Salivary Testosterone & Cortisol


Renewed interest by the research community has focused on the salivary testosterone/cortisol (T/C) ratio and its supporting biological mechanisms. Here we explore the scientific literature and provide a summary of our findings

Research suggests that testosterone and cortisol work together as part of a biological system influencing very basic and primary reactions to threats by balancing the hypothalamus-pituitary-adrenal (HPA) axis and the hypothalamus-pituitary-gonadal (HPG) axis responses (9). In response to a stressor, the human body increases the production of cortisol and decreases production of testosterone (12). In sports and exercise studies, salivary bioscience researchers have already concluded that the balancing of the T/C ratio not only supports a healthier lifestyle, but it can also act as a hormonal biomarker that targets overtraining and susceptibility to certain diseases and disorders (5,10).

General findings in the context of exercise and sports performance show the value of the salivary T/C ratio when observing training intensity levels and for determining potential overtraining and recovery (3, 7). This is often seen when there is evidence of a low or decreased T/C ratio (i.e., cortisol rises and testosterone decreases (2). In athletes, the T/C ratio has also been associated with skeletal muscle atrophy, as it may be reflective of the anabolism/catabolism balance of skeletal muscle as well (11).

However, the salivary T/C story doesn’t end with sports and performance. Additional research is beginning to encompass a much broader impact of the T/C ratio by expanding into the field of social biology. Findings related to social aggression and the T/C ratio have revealed a significant positive relationship between testosterone and aggression in subjects with high cortisol levels, but not in subjects with average to low cortisol levels (8). Now, research is beginning to elucidate the T/C ratio as a consistent hormonal marker for social aggression and criminal or aggressive tendencies (8,9).

While research continues to define the significant health implications of monitoring the T/C ratio by further understanding its biobehavioral influences, the team at Salimetrics stands ready to support you with convenient sample collection methods, salivary analysis and accurate results, so that you can unlock the potential of the T/C ratio in your research

References
1. Guilhem, G. et al (2015). Salivary Hormones Response to Preparation and Pre-competitive Training of World-class Level Athletes. Front Physiol, PMID, 26635619.
2. Lippi, G. et al (2016). Analytical Evaluation of Free Testosterone and Cortisol Immunoassays in Saliva as a Reliable Alternative to Serum in Sports Medicine. J Clin Lab Anal, PMID, 26990800.
3. Kreher, J.B. et al (2012). Overtraining Syndrome. Sports Health, 4(2), 128–138.
4. Hug, M. et al (2003). Training modalities: over-reaching and over-training in athletes, including a study of the role of hormones. Best Pract Res Clin Endocrinol Metab, 17(2), 191-209.
5. Filaire, E. et al (2001). Preliminary results on mood state, salivary testosterone:cortisol ratio and team performance in a professional soccer team. Eur J Appl Physiol, 86(2), 179-84.
6. Ghiciuc, C.M. et al (2015). Imbalance in the diurnal salivary testosterone/cortisol ratio in men with severe obstructive sleep apnea: an observational study. Braz J Otorhinolaryngol, S1808-8694(15), 00241-4.
7. Glenn, A.L. et al (2012). Increased testosterone to cortisol ratio in psychopathy. J Abnorm Psychol, 120(2), 389-399.
8. Denson, T.F. et al (2013). Endogenous testosterone and cortisol jointly influence reactive aggression in women. Psychoneuroendocrinology, 38(3), 416-24.
9. Terburg, D. et al (2009). The testosterone-cortisol ratio: A hormonalmarker for proneness to social aggression. Int J Law Psychiatry, 32(4), 216-23

Talk to us about our World Leading Salivary Cortisol and Salivary Testosterone Assays


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Monday, 27 June 2016

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The ONLY Saliva-Based, Scientific Newsletter: Salivary Bioscience Bulletin

Operate at the cutting edge with a free salivary bioscience industry report to benefit your research.  This report offers the latest advancements in the field of Salivary Research, updated saliva assay protocols and collection techniques; it's delivered straight to your inbox, NO more than 4 times per year!

What do I get?

  • News on current research involving salivary analytes
  • Links to selected peer-reviewed publications
  • Up-to-date information on the best saliva collection methods, collection devices, and assay techniques
  • Technical tips to improve assay performance and results
  • No more than SIX issues per year

Sunday, 26 June 2016

New Cortisol research paper from The University of Sydney: Cortisol response and psychological distress predict susceptibility to false memories for a trauma film

Cortisol and Memory Paper submitted by,  Dr Lauren Monds University of Sydney
Abstract
For eyewitness testimony to be considered reliable, it is important to ensure memory remains accurate following the event. As many testimonies involve traumatic, as opposed to neutral, events, it is important to consider the role of distress in susceptibility to false memories. The aim of this study was to investigate whether cortisol response following a stressor would be associated with susceptibility to false memories. Psychological distress responses were also investigated, specifically, dissociation, intrusions, and avoidance. Participants were allocated to one of three conditions: those who viewed a neutral film (N = 35), those who viewed a real trauma film (N = 35), and a trauma "reappraisal" group where participants were told the film was not real (N = 35). All received misinformation about the film in the form of a narrative. Participants provided saliva samples (to assess cortisol) and completed distress and memory questionnaires. Cortisol response was a significant predictor of the misinformation effect. Dissociation and avoidance were related to confabulations. In conclusion, following a stressor an individual may differ with regard to their psychological response to the event, and also whether they experience a cortisol increase. This may affect whether they are more distressed later on, and also whether they remember the event accurately

Monday, 13 June 2016

Researching Sport and Exercise Sciences, Competitive Training, Recovery, Human Physiology, Stress, Hormones?


The value of saliva monitoring in sport









The easy, stress-free, non-invasive nature of saliva collection makes it one of the most accessible body fluids and it has been shown to have potential value in studying normal human physiology as well as pathology. Sport scientists have long been using salivary markers as indicators of immune system status and the stress response to exercise and training, both in the context of research studies examining the impact of acute exercise on immune-endocrine responses and in applied settings to monitor athletes, including professional footballers, over the course of a competitive season (Papacosta & Nassis 2011). 

In conjunction with the use of stress and mood state questionnaires, salivary measures can provide useful information for the sport scientist, team doctor and coach to evaluate the impact of training and competition on the athlete’s immune and endocrine systems. Such data can be used to assess how the athlete/player is coping with the demands of training, competition and other sources of life stress. The measurement of salivary secretory immunoglobulin A (SIgA), cortisol (C) and testosterone (T) have proved useful in this regard. Stressed athletes exhibit depressed levels of SIgA and an elevated cortisol/testosterone (C/T) ratio. Recently, this approach has been applied to the monitoring of elite athletes, rugby and football players over the course of the season. While the coach may not use this information to directly inform his team selection, it may prove useful to identify individuals who are not coping well with stress, allowing appropriate training, psychological, nutritional or medicinal interventions to take place to reduce the chance of burnout and illness.

The following biomarkers can be measured in saliva:
Cortisol/Testosterone Ratio

Here we highlight Salivary Testosterone as described for us by Professor Mike Gleeson, Loughborough University here in the UK:

Testosterone – Recognized as the male reproductive steroid hormone, testosterone has anabolic effects that promote muscle protein synthesis. Testosterone levels increase after intense exercise and high-response levels of testosterone after a heavy workout increase muscle repair, muscle power, recovery, and endurance. A low testosterone response can minimize performance gains, regardless of the quality or length of the workout. Circulating and salivary testosterone levels and responses to exercise tend to fall during periods of chronic stress and intensified training and so can be useful to monitor the development of overreaching during training camps (Hough et al. 2015) and recovery during tapering (Papacosta et al. 2013) ahead of competition. Testosterone levels can also influence mood and aggression. In a study on elite rugby union players, across the entire team, pregame salivary testosterone concentrations were significantly higher for winning games than losses (Gaviglio et al. 2014). Game-ranked performance score was correlated to the team's pregame salivary testosterone concentrations. Thus, monitoring game-day concentrations of salivary free testosterone may help identify competitive readiness in rugby union matches. For the backs, but not the forwards, the pregame C/T ratio was lower for winning games suggesting that monitoring weekly training loads and enhancing recovery modalities between games may also assist with favourable performance and outcome in rugby union matches.

C/T Ratio – The cortisol/testosterone ratio is commonly used as an index for overtraining and recovery. As athletes or games players become more stressed through repeated match play, training, and inadequate recovery the secretion of the adrenal glucorticoid hormone cortisol is increased while the sex steroid testosterone decreases. A published example of results from a study on England rugby union players (Gleeson et al. 2007) competing in several international matches on consecutive weeks illustrates the potential value of regular monitoring of players during critical stages of the season.

Salimetrics Testosterone Assay Kit has also been formatted to minimize cross reactivity for related steroids.Testosterone exhibits a diurnal rhythm, with highest levels in the morning and a nadir around midnight. In men, testosterone plays an important role in the development of male reproductive tissues including the testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle, bone mass, and hair growth. In blood, only 1-10% of testosterone is in its unbound or biologically active form. The remaining testosterone is bound to serum proteins whereas the majority of testosterone in saliva is not protein-bound. Salivary testosterone levels are unaffected by salivary flow rate. The serum-saliva correlation for testosterone is very high for males, but only modest for females.​
 
Target Analyte:Testosterone
Format: 96-well plate
Type: Quantitative
Method: ELISA/EIA
Calibrator range: 6.1 pg/mL - 600 pg/mL
Sensitivity: 1 pg/mL
Saliva volume/test: 25 µL
Incubation time: 1.5 hours
Tests per kit:  76 (singlet)

Correlation with serum: 0.96

Pricing UK/Europe: £209 €292.60  (76 Singlet Tests)

europe@salimetrics.com or call +44 (0) 1638 782619 

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