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Nathan Goodyear

Cortisol Exerts Bi-Phasic Regulation of Inflammation in Humans - 0 views

  • GCs induce increased cellular expression of receptors for several pro-inflammatory cytokines including interleukin (IL)-1 (Spriggs et al. 1990), IL-2 (Wiegers et al. 1995), IL-4 (Paterson et al. 1994), IL-6 (Snyers et al. 1990), and IFN-g (Strickland et al. 1986), as well as GM-CSF
  • GCs have also been shown to stimulate effector cell functions including phagocytosis by monocytes (van der Goes et al. 2000), effector cell proliferative responses (Spriggs et al. 1990), macrophage activation (Sorrells and Sapolsky 2010), and a delay of neutrophil apoptosis
  • a concentration- and time-dependent range of GC effects that are both pro- and anti-inflammatory
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  • basal (diurnal) concentrations of cortisol do not exert an anti-inflammatory effect on several pro-and anti-inflammatory mediators of the human immune inflammatory response
  • withdrawal of cortisol activity in vivo did not lead to increased inflammatory responsiveness of immune effector cells
  • maximal suppression of inflammation was achieved by a stress-associated, but still physiologic, cortisol concentration. There was no greater anti-inflammatory effect at higher cortisol concentrations (Yeager et al. 2005) although IL-10 concentrations continued to increase with increasing cortisol concentrations as we and others have shown
  • acutely, physiological cortisol concentrations are anti-inflammatory and, as proposed, act to limit over expression of an inflammatory response that could lead to tissue damage
  • Acutely, cortisol has anti-inflammatory effects following a systemic inflammatory stimulus (Figure 4). However, a cortisol concentration that acts acutely to suppress systemic inflammation also has a delayed effect of augmenting the inflammatory response to subsequent, delayed stimulu
  • 1) GCs can exert pro-inflammatory effects on key inflammatory processes and, 2) GC regulation of inflammation can vary from anti- to a pro-inflammatory in a time-dependent manner
  • The immediate in vivo effect of both stress-induced and pharmacological GC concentrations is to suppress concurrent inflammation and protect the organism from an excessive or prolonged inflammatory response
  • GCs alone, in the absence of an inflammatory stimulus, up-regulate monocyte mRNA and/or receptors for several molecules that participate in pro-inflammatory signaling, as noted above and in the studies presented here.
  • In humans, as shown here, if in vivo GC concentrations are elevated concurrent with an inflammatory stimulus, anti-inflammatory effects are observed
  • In sharp contrast, with a time delay of 12 or more hours between an increased GC concentration and the onset of an inflammatory stimulus, enhancing effects on inflammation are observed. These effects have been shown to persist in humans for up to 6 days
  • GC-induced enhancement of inflammatory responses is maximal at an intermediate concentration, in our studies at a concentration that approximates that observed in vivo following a major systemic inflammatory stimulus
  • In addition to enhanced responses to LPS, recently identified pro-inflammatory effects of GCs also show enhanced localization of effector cells at inflammatory sites
  • we hypothesize that pre-exposure to stress-associated cortisol concentrations “prime” effector cells of the monocyte/macrophage lineage for an augmented pro-inflammatory response by; a) inducing preparative changes in key regulators of LPS signal transduction, and b) enhancing localization of inflammatory effector cells at potential sites of injury
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    very interesting read on the effects of inflammation on cortisol and visa versa.
Nathan Goodyear

Tissue-Specific Dysregulation of Cortisol Metabolism in Human Obesity - 0 views

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    dysregulated cortisol metabolism plays a role in obesity.  This study looked at obese men.  Decreased liver 11-betaHSD1 activity was found in the liver, with decreased cortisone to cortisol conversion.  Additionally, increase cortisol metabolites were found.  However, there was found to be an increase in 11-betaHSD1 activity in the adipose tissue increasing the cortisone to cortisol conversion indicating an increase in peripheral cortisol production.
Nathan Goodyear

Simultaneous measurement of cortisol in serum and saliva after different forms of corti... - 0 views

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    salivary cortisol shown to accurately reflect the systemic cortisol burden.  This study concluded that saliva cortisol was an accurate assessment tool for the free, biological cortisol in the body.  Saliva an appropriate assessment tool, in the place of serum.
Nathan Goodyear

Salivary Cortisol Can Replace Free Serum Cortisol Measurements in Patients With Septic ... - 0 views

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    Salivary cortisol shown to correlate, significantly, with serum free cortisol.  This can be used as an alternative means to evaluate cortisol in those with septic shock, as this study did.  "Salivary cortisol testing is noninvasive, easy to perform, and can be conducted daily".
Nathan Goodyear

Salivary cortisol determined by enzyme immunoassay is preferable to serum total cortiso... - 0 views

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    salivary testing of cortisol proven to be a better test than blood cortisol.  Published in Clinical Endocrinology, '05.  Salivary cortisol testing is best test to evaluate cortisol levels.
Nathan Goodyear

Diurnal Cortisol Rhythm as a Predictor of Breast Cancer Survival - 0 views

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    Flat and/or abnormal diurnal cortisol patterns found to be associated with earlier mortality in breast cancer.  The flatter cortisol pattern, the earlier the mortality.  Several points here: this highlights the impact of cortisol on the immune system.  Second, this reveals how much of the research has moved to saliva as the gold standard.  This study by the NCI, used salivary cortisol to evaluate the risk of breast cancer survivors.
Nathan Goodyear

Obesity and Gender influence cortisol secretion and metabolism in man - 0 views

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    This study reveals the degree of metabolism dysfunction in obesity. This study suggests that cortisol metabolism is increased in obesity, which results in increased HPA activity resulting in increased peripheral cortisol production. The question to be asked: is serum, salivary, and urinary cortisol results revealing the same function of cortisol. The answer is no.
Nathan Goodyear

Adrenocortical dysregulation as a major player in insulin resistance and onset of obesity - 0 views

  • acute GC secretion during stress mobilizes peripheral amino acids from muscle as well as fatty acids and glycerol from peripheral fat stores to provide substrates for glucose synthesis by the liver
  • chronically elevated GC levels alter body fat distribution and increase visceral adiposity as well as metabolic abnormalities in a fashion reminiscent of metabolic syndrome
  • This local production may play an important role in the onset of obesity and insulin resistance.
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  • In adipocytes, cortisol inhibits lipid mobilization in the presence of insulin, thus leading to triglyceride accumulation and retention.
  • Since the density of GC receptors is higher in intra-abdominal (visceral) fat than in other fat depots, the activity of cortisol leading to accumulation of fat is accentuated in visceral adipose tissue (24, 158), providing a mechanism by which excessive endogenous or exogenous GC lead to abdominal obesity and IR
  • obese patients generally have normal or subnormal plasma cortisol concentrations
  • This may be explained by an increased intratissular/cellular concentration of cortisol in adipose tissues
  • Intracellular GC may be produced from recycling of GC metabolites such as cortisone in adipose tissues
  • Local GC recycling metabolism is mediated by 11β-hydroxysteroid dehydrogenase enzymes (11β-HSD1 and 11β-HSD2
  • Cortisol also increases 11β-HSD1 expression in human adipocytes
  • In humans, elevated 11β-HSD1 expression in visceral adipose tissue is also associated with obesity
  • even if obese patients generally have normal or subnormal plasma cortisol concentrations (131, 158), triglyceride accumulation in visceral adipose tissue may be due, at least in part, to the local production of GC in insulin- and GC-responsive organs such as adipose tissue, liver, and skeletal muscle
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    another nice article on the dysregulation of cortisol and its role in insulin resistance, metabolic syndrome, and obesity.
Nathan Goodyear

Cortisol, serotonin and depression: all stressed out? - 0 views

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    Some with depression are found to have elevated salivary cortisol and others are not.  Likewise, some with depression have low serotonin and others do not.  The point is that the biochemistry of depression is complex and cortisol, serotonin, 5-HTP, tryptophan all may play a role in an individuals "depression".   One thing not included is the out.  How are these individuals metabolizing their cortisol?  As the author stated, some are hyper secretors of cortisol; why not hyper metabolizers?  Weibe has shown many are.
Nathan Goodyear

Usefulness of salivary cortisol in the diagnosis of hypercortisolism: comparison with s... - 0 views

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    Sensitivity and specificity of saliva evaluation of cortisol approached 100%.   Salivary cortisol correlates extremely well serum cortisol levels.  Birth control pills did result in a decline, but still exceeded 95%.
Nathan Goodyear

Effects of Cortisol on Carbohydrate, Lipid, and Protein Metabolism: Studies of Acute Co... - 0 views

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    This study they looked at the withdrawal of cortisol on glucose homeostasis.  The point is that cortisol has profound effects on glucose homeostasis.  Elevated cortisol or exogenous intake reduces T3 and increases insulin resistance.
Nathan Goodyear

Reliability of hypothalamic-pituitary-adrena... [Eur J Epidemiol. 2011] - PubMed - NCBI - 0 views

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    Study finds salivary cortisol testing is "reliable" measure of chronic cortisol production.  This study found similarity between diurnal cortisol and dexamethasone suppressed cortisol and adrenal gland volume based on literature review.
Nathan Goodyear

Urinary Cortisol and Cortisol Metabolite Excretion in Chronic Fatigue Syndrome - 0 views

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    low cortisol is a frequent finding in chronic fatigue syndrome.  However, in the urine, the cortisol levels may be normal.  This is a reflection of increased metabolism of cortisol.  This is not a contradiction, but a metabolic effect.
Nathan Goodyear

Urinary Cortisol and Cortisol Metabolite Excretion in Chronic Fatigue Syndrome - 0 views

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    It has been suggested in the literature that low salivary cortisol is a common finding in those with chronic fatigue. This study found no difference in the cortisol metabolite excretion. This would suggest that an increase metabolization of cortisol exists in those with CFS.
Nathan Goodyear

Associations of Salivary Cortisol Levels with Metabolic Syndrome and Its Components: Th... - 0 views

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    Salivary cortisol testing used to evaluate cortisol pattern in those with metabolic syndrome.  In this study, they found no difference in cortisol pattern in people with metabolic syndrome.
Nathan Goodyear

Salivary Cortisol Can Replace Free Serum Cortisol Measurements in Patients With Septic ... - 0 views

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    salivary cortisol testing is shown to be good alternative to serum cortisol testing.  "very good correlation", "noninvasive", "easy to perform" are just some of the descriptions of salivary cortisol testing in this study
Nathan Goodyear

Salivary Cortisone Is a Potential Biomarker for Serum Free Cortisol - 0 views

  • Salivary cortisol is a useful surrogate for circulating free cortisol
  • Salivary cortisone has potential as a useful surrogate for serum free cortisol in research and clinical assessment
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    salivary cortisol  shown to be good measurement tool of free circulating cortisol. 
Nathan Goodyear

Midnight salivary cortisol for the initial diagnos... [J Clin Endocrinol Metab. 2004] -... - 0 views

  • Measuring midnight salivary cortisol is an easy and noninvasive means of diagnosing hypercortisolism. Its diagnostic accuracy is identical to, if not better than, that of previously described gold standards
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    salivary cortisol testing is "better than, that of previously described gold standards."  This makes salivary cortisol testing the gold standard for assessing cortisol levels
Nathan Goodyear

Salivary cortisol as a biomarker in stress researc... [Psychoneuroendocrinology. 2009] ... - 0 views

  • psychobiological mechanisms, which trigger the hypothalamus-pituitary-adrenal axis (HPAA) can only indirectly be assessed by salivary cortisol measures. The different instances that control HPAA reactivity (hippocampus, hypothalamus, pituitary, adrenals) and their respective modulators, receptors, or binding proteins, may all affect salivary cortisol measures.
  • linear relationship with measures of plasma ACTH and cortisol in blood or urine does not necessarily exist
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    saliva cortisol testing is a better assessment tool for HPA axis function, compared to serum cortisol
Nathan Goodyear

Behaviour of saliva cortisol [C], testost... [Eur J Appl Physiol. 2003] - PubMed - NCBI - 0 views

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    salivary hormone evaluation reveals cortisol increases during athletic  competition due primarily to a increase in salivary cortisol production.  The result is a decrease in T:C ratio during competition.  In the recovery phase, cortisol decreases to baseline, but the testosterone rises above baseline, thus increasing the T:C ratio in the recovery phase.  This lasted up to 5 days in this study.
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