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Nathan Goodyear

The effect of common genetic variati... [J Clin Endocrinol Metab. 2012] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...22112815

saliva salivary hormone hormones depression 11-betaHSD1 HPA SNPs

shared by Nathan Goodyear on 10 Oct 12 - No Cached
  • Nathan Goodyear on 10 Oct 12
     
    hyperactive HPA axis associated with depression. This is becoming evident in the literature.  This study looked at SNPS in the etiology of elevated cortisol and/or androstenedione.  They followed the results with saliva and found that 3 SNPS were associated with increased 11Beta-HSD1 activity and associated increased depression.
Nathan Goodyear

Decreased cortisol awakening respon... [Psychoneuroendocrinology. 2005] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...15808926

stress ELE early life stressor cortisol saliva salivary hormones hormone HPA

shared by Nathan Goodyear on 30 Apr 12 - No Cached
  • Nathan Goodyear on 30 Apr 12
     
    early life stressors shown to reduce morning cortisol on salivary testing.  This indicates an altered HPA axis.
Nathan Goodyear

Decreased androgen levels and obesity in men. [Ann Med. 1996] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...8932500

obesity low T testosterone hypogonadotrophic hypogonadism estrogen aromatase LH

shared by Nathan Goodyear on 11 Feb 12 - No Cached
  • Nathan Goodyear on 11 Feb 12
     
    As obesity increases, so Testosterone decreases.  Hypogondatrophic hypogonadism is associated is found in obesity.  This is no surprise, as aromatase activity is increased in fat resulting in elevated Estrogen, which provides negative feedback to the hypothalamic-pituitary axis.  This results in decrease LH and thus Testosterone production.
Nathan Goodyear

Altered Cortisol Metabolism in Polycystic Ovary Syndrome: Insulin Enhances 5α... - 0 views

jcem.endojournals.org/...5907.long

PCOS PCO polycystic ovaries insulin IR resistance steroid 5-alpha reductase androgens

shared by Nathan Goodyear on 13 Mar 12 - No Cached
  • Nathan Goodyear on 13 Mar 12
     
    insulin, in women with PCOS, promotes increased 5-alpha reductase activity.  This results in a dysregulated HPA axis, promoting increased cortisol and androgen levels.
Nathan Goodyear

Diagnosis of secondary adrenal insufficiency in patients with hypothalamic-pituitary di... - 0 views

www.eje-online.org/...9.full

saliva salivary cortisol hormone hormones HPA

shared by Nathan Goodyear on 22 Aug 12 - No Cached
  • Nathan Goodyear on 22 Aug 12
     
    European journal of endocrinology article compared serum to salivary cortisol and found them to be equal, but due to ease of collection, salivary cortisol to be preferable.  This article was using cortisol to assess HPA axis dysfunction.
Nathan Goodyear

Circadian disruption in cancer: a neuroend... [Brain Behav Immun. 2003] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...12946654

Cortisol saliva salivary hormone hormones test testing HPA cancer stress

shared by Nathan Goodyear on 28 Nov 11 - No Cached
  • Nathan Goodyear on 28 Nov 11
     
    disrupted cortisol rhythm or pattern due to stress is a pathway to disease.  A disrupted HPA axis is a disrupted immune system.
Nathan Goodyear

Anxiety disorders and salivary cort... [Psychoneuroendocrinology. 2012] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...22776419

hormone hormones saliva salivary cortisol HPA anxiety

shared by Nathan Goodyear on 30 Jul 12 - No Cached
  • Nathan Goodyear on 30 Jul 12
     
    low am cortisol, found in adults with "long-lasting" anxiety.  The proposed reason is a physiologic down regulation of the HPA axis.
Nathan Goodyear

The role of gut microbiota in the gut-brain axis: current challenges and perspectives. ... - 0 views

www.researchgate.net/...nt_challenges_and_perspectives

gut brain microbiota dysbiosis gut-brain axis

shared by Nathan Goodyear on 17 Feb 14 - No Cached
  • Nathan Goodyear on 17 Feb 14
     
    Great discussion of the gut brain connection.
Nathan Goodyear

Acute Glucocorticoid Deficiency and Diabetes Insipidus Are Common After Acute Traumatic... - 0 views

jcem.endojournals.org/...3229.abstract

traumatic brain injury brain injury HPA cortisol

shared by Nathan Goodyear on 21 Aug 13 - No Cached
  • Nathan Goodyear on 21 Aug 13
     
    High rate (78%) of those post TBI have low cortisol levels due to damaged HPA axis.  Low cortisol levels post TBI are associated with an increase mortality rate and increased long-term HPA disruption.
Nathan Goodyear

In Men, Peripheral Estradiol Levels Directly Reflect the Action of Estrogens at the Hyp... - 0 views

jcem.endojournals.org/...3324.long

low T low Testosterone low Testosterone aromatase Estradiol

shared by Nathan Goodyear on 27 Sep 13 - No Cached
  • Nathan Goodyear on 27 Sep 13
     
    peripheral aromatase activity and Testosterone to Estradiol production have central HPA axis suppression resulting in decreased LH and FSH and low Testosterone.
Nathan Goodyear

Salivary cortisol for assessment of hypothalamic-p... [Neuroimmunomodulation. 2009] - P... - 0 views

www.ncbi.nlm.nih.gov/...19571589

saliva salivary hormone hormones testing cortisol

shared by Nathan Goodyear on 15 Nov 10 - No Cached
  • Sampling for salivary cortisol determination is a sensitive, specific and pain-free procedure and it is therefore very useful for following healthy and sick children before, during and after pharmacological interventions
  • Nathan Goodyear on 15 Nov 10
     
    Salivary cortisol for assessment of hypothalamic-pituitary-adrenal axis function.
Nathan Goodyear

Measurement and meaning of salivary cortisol: a fo... [Stress. 2008] - PubMed result - 0 views

www.ncbi.nlm.nih.gov/...17853059

saliva testing hormone salivary cortisol hormones

shared by Nathan Goodyear on 22 Nov 10 - No Cached
  • the review highlights the use of salivary cortisol measurements to provide information about HPA axis dysfunction associated with psycho- and patho-physiological conditions in children. Novel applications for salivary cortisol measurements in future research into HPA axis activity in children are also discussed.
  • Nathan Goodyear on 22 Nov 10
     
    Measurement and meaning of salivary cortisol: a focus on health and disease in children.
Nathan Goodyear

Altered cortisol response to psychologic stress in... [Psychosom Med. 2005 Mar-Apr] - P... - 0 views

www.ncbi.nlm.nih.gov/...15784794

cortisol saliva salivary testing breast cancer fatigue

shared by Nathan Goodyear on 26 Jan 11 - No Cached
  • Nathan Goodyear on 26 Jan 11
     
    salivary cortisol used to evaluate HPA axis dysfunction, to predict fatigue, in breast cancer survivors
Nathan Goodyear

Leptin and the pituitary-thyroid axis: a comparative study in lean, obese, hypothyroid ... - 0 views

onlinelibrary.wiley.com/...abstract

thyroid hypothyroid hypothyroidism leptin obesity overweight

shared by Nathan Goodyear on 08 Mar 11 - No Cached
  • The data are consistent with the hypothesis that leptin and the pituitary–thyroid axis interact in the euthyroid state, and that hypothyroidism reversibly increases leptin concentrations
  • Nathan Goodyear on 08 Mar 11
     
    thyroid and leptin interact to control weight
Nathan Goodyear

Cortisol awakening response and nighttime salivary... [Yonsei Med J. 2011] - PubMed result - 0 views

www.ncbi.nlm.nih.gov/...21488186

saliva salivary cortisol hormone testing HPA hypothalamus pituitary adrenal

shared by Nathan Goodyear on 13 Jul 11 - No Cached
  • Nathan Goodyear on 13 Jul 11
     
    salivary cortisol useful in evaluating hypothalamus-pituitary-adrenal axis system
Nathan Goodyear

The morning salivary cortisol response in burnout. [J Psychosom Res. 2005] - PubMed result - 0 views

www.ncbi.nlm.nih.gov/...16186006

cortisol saliva salivary hormone testing stress HPA

shared by Nathan Goodyear on 13 Jul 11 - No Cached
  • Nathan Goodyear on 13 Jul 11
     
    cortisol salivary testing.  elevated am cortisol reflective of HPA axis dysfunction due to stress.
Nathan Goodyear

Sex hormone synthesis, regulation, and function | McMaster Pathophysiology Review - 0 views

www.pathophys.org/sexhormones

hormones HPA Testosterone DHEA estradiol LH FSH Progesterone androgens estrogen

shared by Nathan Goodyear on 02 Oct 17 - No Cached
  • Nathan Goodyear on 02 Oct 17
     
    Good review of the HPA-sex hormone pathways, called the Hypothalamic-Pituitary-Gondal axis, including HP feedback.  This is not a study but has nice diagrams. This is based on 14 referenced articles and 1 book chapter.
Nathan Goodyear

https://www.researchgate.net/profile/Osama_Arafat/publication/234135338_METHYLCOBALAMIN... - 0 views

www.researchgate.net/...C-HYPOPHYSEAL-ADRENAL-AXIS.pdf

methylcobalamin methyl-B12 B12 hypertension norepinephrine adrenal medulla adrenal

shared by Nathan Goodyear on 18 Dec 17 - No Cached
  • Nathan Goodyear on 18 Dec 17
     
    Animal study points to methylB12 as the cause of an increase in adrenal medulla norepinephrine production.  This has significant implications in individuals with hypertension.
Nathan Goodyear

The Growth Hormone/Insulin-Like Growth Factor-I Axis in Exercise and Sport - 0 views

edrv.endojournals.org/...603.long

growth hormone GH IGF-1 exercise health sport growth hormone

shared by Nathan Goodyear on 21 Jan 13 - No Cached
  • Nathan Goodyear on 21 Jan 13
     
    Review of the physiological roles of GH and IGF-1 during exercise.  The focus is on maximizing the normal physiologic response, not supra physiologic.
Nathan Goodyear

Testosterone: a metabolic hormone in health and disease - 0 views

joe.endocrinology-journals.org/...R25.full

male hormone hormones testosterone hypogonadal-obesity-adipocytokine hypothesis

shared by Nathan Goodyear on 08 May 13 - No Cached
  • E2 and the inflammatory adipocytokines tumour necrosis factor α (TNFα) and interleukin 6 (IL6) inhibit hypothalamic production of GNRH and subsequent release of LH and FSH from the pituitary
  • Leptin, an adipose-derived hormone with a well-known role in regulation of body weight and food intake, also induces LH release under normal conditions via stimulation of hypothalamic GNRH neurons
  • In human obesity, whereby adipocytes are producing elevated amounts of leptin, the hypothalamic–pituitary axis becomes leptin resistant
  • ...39 more annotations...
  • there is evidence from animal studies that leptin resistance, inflammation and oestrogens inhibit neuronal release of kisspeptin
  • Beyond hypothalamic action, leptin also directly inhibits the stimulatory action of gonadotrophins on the Leydig cells of the testis to decrease testosterone production; therefore, elevated leptin levels in obesity may further diminish androgen status
  • Prostate cancer patients with pre-existing T2DM show a further deterioration of insulin resistance and worsening of diabetic control following ADT
  • ADT for the treatment of prostatic carcinoma in some large epidemiological studies has been shown to be associated with an increased risk of developing MetS and T2DM
  • Non-diabetic men undergoing androgen ablation show increased occurrence of new-onset diabetes and demonstrate elevated insulin levels and worsening glycaemic control
  • increasing insulin resistance assessed by glucose tolerence test and hypoglycemic clamp was shown to be associated with a decrease in Leydig cell testosterone secretion in men
  • The response to testosterone replacement of insulin sensitivity is in part dependent on the androgen receptor (AR)
  • Low levels of testosterone have been associated with an atherogenic lipoprotein profile, characterised by high LDL and triglyceride levels
  • a positive correlation between serum testosterone and HDL has been reported in both healthy and diabetic men
  • up to 70% of the body's insulin sensitivity is accounted for by muscle
  • Testosterone deficiency is associated with a decrease in lean body mass
  • relative muscle mass is inversely associated with insulin resistance and pre-diabetes
  • GLUT4 and IRS1 were up-regulated in cultured adipocytes and skeletal muscle cells following testosterone treatment at low dose and short-time incubations
  • local conversion of testosterone to DHT and activation of AR may be important for glucose uptake
  • inverse correlation between testosterone levels and adverse mitochondrial function
  • orchidectomy of male Wistar rats and associated testosterone deficiency induced increased absorption of glucose from the intestine
  • (Kelley & Mandarino 2000). Frederiksen et al. (2012a) recently demonstrated that testosterone may influence components of metabolic flexibility as 6 months of transdermal testosterone treatment in aging men with low–normal bioavailable testosterone levels increased lipid oxidation and decreased glucose oxidation during the fasting state.
  • Decreased lipid oxidation coupled with diet-induced chronic FA elevation is linked to increased accumulation of myocellular lipid, in particular diacylglycerol and/or ceramide in myocytes
  • In the Chang human adult liver cell line, insulin receptor mRNA expression was significantly increased following exposure to testosterone
  • Testosterone deprivation via castration of male rats led to decreased expression of Glut4 in liver tissue, as well as adipose and muscle
  • oestrogen was found to increase the expression of insulin receptors in insulin-resistant HepG2 human liver cell line
  • FFA decrease hepatic insulin binding and extraction, increase hepatic gluconeogenesis and increase hepatic insulin resistance.
  • Only one, albeit large-scale, population-based cross-sectional study reports an association between low serum testosterone concentrations and hepatic steatosis in men (Völzke et al. 2010)
  • This suggests that testosterone may confer some of its beneficial effects on hepatic lipid metabolism via conversion to E2 and subsequent activation of ERα.
  • hypogonadal men exhibiting a reduced lean body mass and an increased fat mass, abdominal or central obesity
  • visceral adipose tissue was inversely correlated with bioavailable testosterone
  • there was no change in visceral fat mass in aged men with low testosterone levels following 6 months of transdermal TRT, yet subcutaneous fat mass was significantly reduced in both the thigh and the abdominal areas when analysed by MRI (Frederiksen et al. 2012b)
  • ADT of prostate cancer patients increased both visceral and subcutaneous abdominal fat in a 12-month prospective observational study (Hamilton et al. 2011)
  • Catecholamines are the major lipolysis regulating hormones in man and regulate adipocyte lipolysis through activation of adenylate cyclase to produce cAMP
  • deficiency of androgen action decreases lipolysis and is primarily responsible for the induction of obesity (Yanase et al. 2008)
  • may be some regional differences in the action of testosterone on subcutaneous and visceral adipose function
  • proinflammatory adipocytokines IL1, IL6 and TNFα are increased in obesity with a downstream effect that stimulates liver production of CRP
  • observational evidence suggests that IL1β, IL6, TNFα and CRP are inversely associated with serum testosterone levels in patients
  • TRT has been reported to significantly reduce these proinflammatory mediators
  • This suggests a role for AR in the metabolic actions of testosterone on fat accumulation and adipose tissue inflammatory response
  • testosterone treatment may have beneficial effects on preventing the pathogenesis of obesity by inhibiting adipogenesis, decreasing triglyceride uptake and storage, increasing lipolysis, influencing lipoprotein content and function and may directly reduce fat mass and increase muscle mass
  • Early interventional studies suggest that TRT in hypogonadal men with T2DM and/or MetS has beneficial effects on lipids, adiposity and parameters of insulin sensitivity and glucose control
  • Evidence that whole-body insulin sensitivity is reduced in testosterone deficiency and increases with testosterone replacement supports a key role of this hormone in glucose and lipid metabolism
  • Impaired insulin sensitivity in these three tissues is characterised by defects in insulin-stimulated glucose transport activity, in particular into skeletal muscle, impaired insulin-mediated inhibition of hepatic glucose production and stimulation of glycogen synthesis in liver, and a reduced ability of insulin to inhibit lipolysis in adipose tissue
  • Nathan Goodyear on 08 May 13
     
    Great review of the Hypogonadal-obesity-adipocytokine hypothesis.
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