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Nathan Goodyear

Interaction of gonadal status with syste... [Support Care Cancer. 2011] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...20221887

hormone hormones pancreatic cancer pancreas

shared by Nathan Goodyear on 17 Sep 13 - No Cached
  • Nathan Goodyear on 17 Sep 13
     
    pancreatic cancer survival risk is shorted by 2.43 with elevated estradiol in women.  This risk is linked to an increase in TNF alpha.  In contrast, men survival risk was worse by 1.96 odds ratio with low Testosterone.  Again, inflammation was the culprit.
Nathan Goodyear

Gonadal Steroids and Body Composition, Strength, and Sexual Function in Men - NEJM - 0 views

www.nejm.org/...NEJMoa1206168

Testosterone Estradiol goserelin men male hormone hormones

shared by Nathan Goodyear on 27 Sep 13 - No Cached
  • Nathan Goodyear on 27 Sep 13
     
    This study confirms what we know about Testosterone, but this study finds that Estradiol aids libido and fat loss.  The conclusion on Estradiol I believe to be extremely premature.  First, it flies in the face of all the accumulative data on estradiol, second, what normal physiology is being replicated with goserelin???  Goserelin has been shown to decrease Prolactin which can effect libido also.  What about the potential there?  The men included in the study were described as "healthy".  So, you are taking "healthy" normal funcitoning men, throwing in a monkey wrench and looking at the effects of your monkey wrench.  Sorry, not physiologic.  In all my practice, I have seen one man with low Estradiol levels.  There is no reference to the hormone levels in the men preceding the suppression with goserelin.  This is a study that lacks application.
Nathan Goodyear

Evaluation of the hypothalamic-pituitary-gonadal a... [Andrology. 2013] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...24282162

low T Testosterone diabetes LH men male hormone hormones glucose

shared by Nathan Goodyear on 02 Dec 13 - No Cached
  • Nathan Goodyear on 02 Dec 13
     
    Increasing glucose levels associated with declining LH pulses in men with type II diabetes.  This is one proposed mechanism for low T in men.  There has been great debate about if Low T was in part the cause of Diabetes or an effect of diabetes.  This proposes that low T is due to a decreased LH pulse as a result of rising glucose.
Nathan Goodyear

Gonadal Steroids and Immunity - 0 views

edrv.endojournals.org/...369.abstract

Testosterone healing surgery

shared by Nathan Goodyear on 10 Dec 13 - No Cached
  • Nathan Goodyear on 10 Dec 13
     
    Just the abstract is available, but this article reported that older men with higher Testosterone healed slower post surgery.
Nathan Goodyear

PLOS ONE: Probiotic Microbes Sustain Youthful Serum Testosterone Levels and Testicular ... - 0 views

journals.plos.org/...article

hormone hormones low T low Testosterone hypogonadism Testosterone probiotic L reuters probiotics Lactobacillus lactobacillus reuteri male aging

shared by Nathan Goodyear on 29 Apr 15 - No Cached
  • Studies in both humans and rodents, however, suggest that low testosterone is due to age-related lesions in testes rather than irregular luteinizing hormone metabolism
  • Various dietary factors and diet-induced obesity have been shown to increase the risk for late onset male hypogonadism and low testosterone production in both humans and mice
  • Testosterone deficiency and metabolic diseases such as obesity appear to inter-digitate in complex cause-and-effect relationships
  • ...28 more annotations...
  • dietary supplementation of aged mice with the probiotic bacterium Lactobacillus reuteri makes them appear to be younger than their matched untreated sibling mice
  • These results indicate that gut microbiota induce modulation of local gastrointestinal immunity resulting in systemic effects on the immune system which activate metabolic pathways that restore tissue homeostasis and overall health
  • all these studies we consistently observed that young and aged mice consuming purified L. reuteri organisms had particularly large testes and a dominant male behavior.
  • The testes of probiotic-fed aged mice were rescued from both seminiferous tubule atrophy and interstitial Leydig cell area reduction typical of the normal aging process. Preservation of testicular architecture despite advanced age or high-fat diet coincided with remarkably high levels of circulating testosterone. The beneficial effects of probiotic consumption were recapitulated by the depletion of the pro-inflammatory cytokine Il-17.
  • feeding of L. reuteri consistently increased the gonadal weights, consumption of a non-pathogenic strain of Escherichia coli (E. coli) K12 organisms did not affect testicular weight
  • mice with dietary L. reuteri supplements were rescued from diet-induced obesity and had normal body weight and lean physique
  • Despite the comparable numbers of ST profiles, we determined that testes from L. reuteri-treated mice had increased ST cross-sectioned profiles
  • the probiotic organism induced prominent Leydig cell accumulations in the interstitial tissue between the ST's
  • The probiotic-associated increase of interstitial Leydig cell areas was sustained with advancing age at 7 (CD vs CD+LR, P = 0.0025; CD+E.coli vs CD+LR, P = 0.0251) and 12 months
  • mice eating L. reuteri had profoundly increased levels of circulating testosterone regardless of the type of diet they consumed
  • blocking pro-inflammatory Il-17 signaling entirely recapitulates the beneficial effects of probiotics
  • previous studies we found that dietary probiotics counteract obesity [19] and age-related integumentary pathology [18] at least in part by down-regulating systemic pro-inflammatory IL-17A-dependent signaling
  • Testes histomorphometry and serum androgen concentration data were both suggestive of a probiotic-associated up-regulation of spermatogenesis in mice
  • Lactobacillus reuteri we discovered that aging male animals had larger testes compared to their age-matched controls
  • xamined testes of probiotic microbe-fed mice and found that they had less testicular atrophy coinciding with higher levels of circulating testosterone compared to their age-matched controls
  • Similar testicular health benefits were produced using systemic depletion of the pro-inflammatory cytokine Il-17 alone, implicating a chronic inflammatory pathway in hypogonadism
  • One specific aspect of this paradigm is reciprocal activities of pro-inflammatory Th-17 and anti-inflammatory Treg cells
  • Feeding of L. reuteri organisms was previously shown to up-regulate IL-10 levels and reduce levels of IL-17 [19] serving to lower systemic inflammation
  • insufficient levels of IL-10 may increase the risk for autoimmunity, obesity, and other inflammatory disease syndromes
  • Westernized diets are also low in vitamin D, a nutrient that when present normally works together with IL-10 to protect against inflammatory disorders
  • Physiological feedback loops apparently exist between microbes, host hormones, and immunity
  • The hormone testosterone has been shown to act directly through androgen receptors on CD4+ cells to increase IL-10 expression
  • studies in both humans and rodents suggest that hypogonadism is due to age-related lesions in testes rather than irregular LH metabolism
  • We postulate that probiotic gut microbes function symbiotically with their mammalian hosts to impart immune homeostasis to maintain systemic and testicular health [34]–[35] despite suboptimal dietary conditions.
  • Dietary factors and diet-induced obesity were previously shown to increase risk for age-associated male hypogonadism, reduced spermatogenesis, and low testosterone production in both humans and mice [2]–[4], [8]–[11], [14]–[17], phenotypic features that in this study were inhibited by oral probiotic therapy absent milk sugars, extra protein, or vitamin D supplied in yogurt.
  • Similar beneficial effects of probiotic microbes on testosterone levels and sperm indices were reported in male mice that had been simultaneously supplemented with selenium
  • L. reuteri-associated prevention of age- and diet-related testicular atrophy correlates with increased numbers and size of Leydig cells
  • the initial changes of testicular atrophy begin to occur in mice from the age of 6 moths onwards [7] and indicates that the trophic effect of L. reuteri on Leydig cells is a key event which precedes and prevents age-related changes in the testes of mice. This effect is reminiscent of earlier studies describing Leydig cell hyperplasia and/or hypertrophy in the mouse and the rat testis that were achievable by the administration of gonadotropins, including human chorionic gonadotropin, FSH and LH
  • Nathan Goodyear on 29 Apr 15
     
    Fascinating study on how the addition of Lactobacillus reuteri increased Testicular size, prevented testicular atrophy, increased serum Testosterone production and protected against diet-induced/obesity-induced hypogonadism.  This was a mouse model
Nathan Goodyear

Salivary Testosterone and a Trinucleotide (CAG) Length Polymorphism in the Androgen Rec... - 0 views

www.ncbi.nlm.nih.gov/...PMC2825741

CAG androgen receptors AR androgen receptor Testosterone hormone hormones male men

shared by Nathan Goodyear on 22 Jun 15 - No Cached
  • Testosterone correlated inversely with participant age (r = −0.39, p = 0.012) and positively with number of CAG repeats
  • transactivation potential of the AR appears to decline in graded relation to an increasing number of CAG repeats, which are distributed over a normative range of 11–37 and, in Caucasian populations, commonly average 21–22 repeats
  • When activated by androgens, ARs translocate to the cell nucleus, where they exert transcriptional control of androgen-dependent genes by binding to androgen response elements within gene regulatory sequences
  • ...10 more annotations...
  • some evidence suggests a high number of CAG repeats may be associated with cognitive aging
  • androgens (like other steroid hormones) promote or repress the expression of genes specifying an array of cellular proteins
  • diurnal variation in testosterone levels
  • salivary testosterone correlated negatively with participant age and positively with CAG length variation in the AR gene
  • CAG repeat number varied inversely with reactivity of the ventral amygdala to facial expressions of negative affect
  • higher salivary testosterone was likewise associated with a greater number of AR CAG repeats
  • relative androgen insensitivity in ARs with a larger number of CAG repeats
  • Because circulating testosterone is regulated via negative feedback through the hypothalamic-pituitary-gonadal axis, diminished androgen sensitivity at higher CAG repeat lengths may reduce feedback suppression of luteinizing hormone (LH). LH would then be maintained at higher levels, in turn promoting higher testosterone production
  • Testosterone up-regulates AVP expression in the amygdala
  • Oxytocin exerts an inhibitory influence on AVP expression in the central amygdala, and the synthesis of oxytocin is mediated by estrogen and estrogen receptors
  • Nathan Goodyear on 22 Jun 15
     
    Study used saliva to measure Testosterone levels in men.  Testosterone levels were inversely associated with age, but positively associated with CAG repeat sequences in the AR.
Nathan Goodyear

Leptin serves body as energy signal | Harvard Gazette - 0 views

news.harvard.edu/...n-serves-body-as-energy-signal

leptin body energy hormones thyroid

shared by Nathan Goodyear on 08 Mar 11 - No Cached
  • replacing leptin to physiologically normal levels during fasting fully restored testosterone to baseline, indicating that leptin regulates the hypothalamic-pituitary- gonadal axis that controls the release of testosterone and estrogen
  • Leptin clearly has some effect on the thyroid hormone axis,
  • including thyroid-stimulating hormone and the free-circulating form of thyroid
  • Nathan Goodyear on 08 Mar 11
     
    Leptin regulates hypothalamic-pituitary axis; and don't forget thyroid too.
Nathan Goodyear

Vitamin D Is an Important Factor in Estrogen Biosynthesis of Both Female and Male Gonads - 0 views

endo.endojournals.org/...1317.full

vitamin d estrogen female infertility deficiency LH FSH

shared by Nathan Goodyear on 24 Sep 11 - No Cached
  • Nathan Goodyear on 24 Sep 11
     
    vitamin D deficiency found to play role in infertility
Nathan Goodyear

Male gonadal function in coeliac disease: 2. Sex hormones. - 0 views

www.ncbi.nlm.nih.gov/...PMC1420172

Testosterone men male hormone hormones celiac disease celiac gluten Estrogen free androgen index DHT

shared by Nathan Goodyear on 27 Jul 14 - No Cached
  • Nathan Goodyear on 27 Jul 14
     
    Interesting study of men with Celiac's disease.  Men with untreated Celiac's were found to have elevated TT and free Androgen index, but DHT was reduced with a slight increase in Estrogen.  LH was elevated.  This is consistent with inflammation increased aromatase activity.
Nathan Goodyear

Evaluation of atorvastatin efficacy and toxicity on spermatozoa, accessory glands and g... - 0 views

www.ncbi.nlm.nih.gov/...PMC4114109

statin statin therapy statins sperm men male fertility atorvastatin hormones

shared by Nathan Goodyear on 04 Sep 14 - No Cached
  • Nathan Goodyear on 04 Sep 14
     
    I really don't understand the purpose of this study.  Why give "healthy" men with normal lipids atorvastatin???  The study found a reduction in TC and LDL, but also a reduction in sperm number, decreased sperm vitality, increased sperm morphology, decreased prostatic acid pho sphatases, epididymal neutral alpha-glucosidase and L-carnitine levels resulted.  
Nathan Goodyear

Longitudinal Effects of Aging on Serum Total and Free Testosterone Levels in Healthy Me... - 0 views

press.endocrine.org/...jcem.86.2.7219

low t low Testosterone Testosterone SHBG FAI free androgen index male hormone hormones aging obesity

shared by Nathan Goodyear on 30 Mar 15 - No Cached
  • NUMEROUS CROSS-SECTIONAL INVESTIGATIONS have demonstrated lower concentrations of circulating testosterone (T) and/or free T in older men
  • Two small-scale longitudinal investigations have observed decreases, with aging, in total T
  • T levels decline at a more or less constant rate, with age, in men, with no period of accelerated decline
  • ...15 more annotations...
  • aging in men is associated with decreases in bone mineral density (BMD) (18, 19), lean body and muscle mass
  • strength (22, 23) and aerobic capacity (24), as well as with increases in total and abdominal body fat, low-density lipoprotein cholesterol, and/or low-density lipoprotein/high-density lipoprotein cholesterol ratios (25, 26, 27, 28), all of which also occur in nonelderly hypogonadal men
  • Most (1, 5, 6, 7, 8, 9), but not all (10, 11, 12), cross-sectional studies have demonstrated a decrease, with age, in total T in men
    • Nathan Goodyear
      Nathan Goodyear on 30 Mar 15
       
      FAI: 100 x total Testosterone nmol/L/SHBG nmol/L
    • Nathan Goodyear
      Nathan Goodyear on 30 Mar 15
       
      These numbers do point to an increase in ng/dl decline in Total Testosterone with increasing age (decade group)
  • total T, but not free T index, tended to decrease with greater BMI is consistent with prior studies showing that obesity is associated with decreases in both SHBG and total T, with an unchanged T-to-SHBG ratio
  • The conventional definition for T levels is statistical (values more than 2 sd below the mean), rather than functional. Such a definition does not reflect clinical realities, such as the existence of characteristic individual set points for circulating hormone levels, below which one, but not another, individual may develop metabolic changes of hormone deficiency; nor does it address the concept of reserve capacity, the possibility that persons with hormone levels 2 sd below the population mean still may have adequate hormone concentrations to meet their metabolic needs.
    • Nathan Goodyear
      Nathan Goodyear on 30 Mar 15
       
      good explanation of problems with just using a number to define low T
  • both T and free T index (a calculated value related to free or bioavailable T) decreased progressively at a rate that did not vary significantly with age, from the third to the ninth decades.
  • contrasts with other studies showing diminished free, as well as total, T in with increasing total (48) or abdominal (49) obesity in men.
  • Our analysis of date-adjusted T and free T index levels, by decade, showed that relatively high numbers of older men in this generally healthy population had at least one hypogonadal value (defined as below the 2.5th percentile for young men)
  • The issue of how properly to define hypogonadism, or indeed any hormone deficiency, remains problematic
  • The decrease in free T index was somewhat steeper than that of total T, owing to a trend for an increase in SHBG with age
  • LH for gonadal function
  • It would clearly be better to define the lower limit of normal for a hormone as: the blood level at which metabolic and/or clinical sequelae of hormone deficiency begin to appear, or the level below which definite benefits can be demonstrated for hormone supplementation for a significant proportion of the population
  • an effect of aging to lower both total and bioavailable circulating T levels at a relatively constant rate, independent of obesity, illness, medications, cigarette smoking, or alcohol intake
  • Nathan Goodyear on 30 Mar 15
     
    Article highlights the problems with the definition of low T.  This article finds consistent decline in Total Testosterone and FAI with increasing age groups, with a significant portion of men > 60 meeting the required levels for "low T".  This study found a decrease in total T and FAI at a consistent rate independent of variables, such as BMI.    This study did find a decrease in SHBG and total T with obesity; in contrast to other studies.
Nathan Goodyear

Overtraining Syndrome - 0 views

www.ncbi.nlm.nih.gov/...PMC3435910

overtraining syndrome OTS exercise athletes cortisol adrenals Testosterone Testosterone:Cortisol hormones

shared by Nathan Goodyear on 29 Jan 16 - No Cached
  • Alterations in the HPA and hypothalamic-pituitary-gonadal axes with a resultant decrease in testosterone:cortisol ratios have been implicated in OTS. Proinflammatory cytokines are potent activators of the HPA system, which cause release of corticotropin-releasing hormone, adrenocorticotropic hormone, and cortisol. These cytokines suppress testosterone through central inhibition
  • Some have suggested that a decreased testosterone:cortisol ratio can be diagnostic of NFO and/or OTS. However, the ratio represents the physiologic strain of training rather than the athlete’s maladaption to that stress
  • Cortisol (catabolic and anti-inflammatory) is converted to inactive cortisone by 11β-HSD2
  • ...2 more annotations...
  • A prospective study found a clinically significant increase in overnight urinary cortisol:cortisone ratio during a high training load period in triathletes, who subsequently underperformed and reported fatigue
  • It is proposed that cytokines may inhibit 11β-HSD2 activity and result in relative increases in cortisol and, hence, catabolism
  • Nathan Goodyear on 29 Jan 16
     
    Overtraining syndrome described.
Nathan Goodyear

Gonadal hormone regulation of MAO and other enzymes in hypothalamic areas. - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...6835476

progesterone MAO serotonin dopamine norepinephrine hormones

shared by Nathan Goodyear on 12 Jul 17 - No Cached
  • Nathan Goodyear on 12 Jul 17
     
    Progesterone increased MAO in prior estrogen treatment.  Without prior treatment, Progesterone did not increase MAO and decrease the monoamine neurotransmitters norepinephrine, serotonin, and dopamine.
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