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Nathan Goodyear

Testosterone and metabolic syndrome Cunningham GR - Asian J Androl - 0 views

www.ajandrology.com/article.asp

Testosterone metabolic syndrome MetS TT total Testosterone SHBG men male hormone hormones Estradiol insulin resistance

shared by Nathan Goodyear on 02 Mar 15 - No Cached
  • The relationship of low testosterone to MetS often is considered to be bidirectional; however, the relationships probably are not direct
  • Many of the components of the MetS are recognized risk factors for the development of cardiovascular disease (CVD)
  • Multiple cross-sectional studies have found low TT and low sex hormone binding globulin (SHBG) levels in Caucasian and African-American men with the MetS, irrespective of age
  • ...20 more annotations...
  • Low TT and SHBG levels also are prevalent in Chinese [7],[8] and Korean [9] men with the MetS
  • Normally 40%-50% of TT is bound to SHBG, so reducing SHBG levels will decrease TT.
  • Hyperinsulinism suppresses SHBG synthesis and secretion by the liver
  • significant increase in SHBG levels occurred after acutely lowering insulin levels in obese men
  • Estradiol levels are increased in men with the MetS, and they are positively correlated with the number of abnormal components of the MetS.
  • Although it is known that estrogen will increase SHBG levels, apparently the hyperinsulinism associated with obesity has a greater effect on SHBG levels
  • Estradiol also can inhibit luteinizing hormone (LH) secretion
  • Inflammatory cytokines are thought to have a direct effect on the pituitary to reduce LH secretion [15] and also a direct effect on Leydig cell secretion of testosterone
  • Low TT Levels have been shown to predict development of the MetS in men with normal BMI
  • Men in the lowest quartiles of serum TT, calculated free testosterone (cFT) and SHBG at baseline had the highest odds ratios for developing the MetS or DM during the 11 years follow-up
  • More recently, investigators conducting population-based studies have reported that only SHBG is associated with future development of the MetS
  • Additional evidence that low TT increases the risk of MetS comes from androgen deprivation treatment of prostate cancer
  • Low TT and low bioavailable testosterone (bT) were each significantly associated with elevated 20 years risk of CVD mortality in an older population in which cause-specific mortality was age, adiposity, and lifestyle-adjusted.
  • combination of low bT and ATP III-defined MetS is associated with increased cardiovascular mortality in men aged 40 years and above
  • in elderly men, testosterone may weakly protect against CVD. Alternatively, low TT may indicate poor general health
  • Muraleedharan and Jones [27] concluded that there is convincing evidence that low T is a biomarker for disease severity and mortality.
  • The evidence that TRT improves insulin sensitivity and glucose control is conflicted
  • It is widely recognized that testosterone treatment can reduce fat mass and increase lean body mass; however, until recently most reports have not been associated with much weight loss
  • Changes in body composition and weight loss are considered potential mechanisms by which testosterone treatment improves insulin sensitivity and glucose control in patients with diabetes. Effects on inflammatory cytokines [38] and changes in oxidative metabolism [39] also have been reported to improve glucose metabolism.
  • Testosterone replacement therapy has been reported to improve some or all of the components of the MetS.
  • Nathan Goodyear on 02 Mar 15
     
    To be read article on Testosterone and Metabolic Syndrome.
Nathan Goodyear

PLOS ONE: Increased Risk of Non-Fatal Myocardial Infarction Following Testosterone Ther... - 0 views

www.plosone.org/...10.1371%2Fjournal.pone.0085805

Testosterone therapy cardiovascular disease men male hormones

shared by Nathan Goodyear on 30 Jan 14 - No Cached
  • For all TT prescription subjects combined, the post/pre prescription rate ratio for MI (RR)was 1.36
  • In men aged 65 years and older the RR was 2.19 (1.27, 3.77), while in men under age 65 years the RR was 1.17
  • increasing RR with increasing age.
  • ...20 more annotations...
  • The RRs were 0.95 (0.54, 1.67) under 55 years
  • 1.35 (0.77, 2.38) at 55–59
  • 1.29 (0.71, 2.35) at 60–64,
  • 1.35 (0.44, 4.18) at 65–69, 1.62
  • 3.43 (1.54, 7.66) at 75 years and older
  • The adjusted post/pre RR for PDE5I across all ages was 1.08
  • For TT prescription, in men under age 65 years, the RR was 2.90 (1.49, 5.62) for those with a history of heart disease and 0.90 (0.61, 1.34) for those without
  • In men aged 65 year and older, the RR was 2.16 (0.92, 5.10) for those with a history of heart disease and 2.21 (1.09, 4.45) for those without.
  • Among men aged 65 years and older, we observed a two-fold increase in the risk of MI in the 90 days after filling an initial TT prescription
  • Among younger men with a history of heart disease, we observed a two to three-fold increased risk of MI in the 90 days following an initial TT prescription and no excess risk in younger men without such a history
  • Among older men, the two-fold increased risk was associated with TT prescription regardless of cardiovascular disease history
  • our own findings appear consistent with a higher frequency of thrombotic events following TT prescription among men with more extensive coronary vascular disease.
  • Our findings are consistent with a recent meta-analysis of placebo-controlled randomized trials of testosterone therapy lasting 12 or more weeks among mainly older men, which reported that testosterone therapy increased the risk of adverse cardiovascular-related events (OR = 1.54, 95%CI:1.09, 2.18), as well as serious adverse cardiovascular-related events (OR = 1.61, 95%CI:1.01, 2.56) which included myocardial infarction along with other conditions
  • This association appeared unrelated to average baseline testosterone level (p = 0.70) but varied by source of funding (p = 0.03), with a stronger summary effect in a meta-analysis of studies not funded by the pharmaceutical industry (OR = 2.06, 95%CI:1.34, 3.17) compared with studies funded by the pharmaceutical industry
    • Nathan Goodyear
      Nathan Goodyear on 30 Jan 14
       
      This supports prior analysis that studies done by pharmaceutical corps will be more favorable to their product(s) than those independently funded.  This is called bias.
  • the evidence supports an association between testosterone therapy and risk of serious, adverse cardiovascular-related events–including non-fatal myocardial infarction–in men
  • there is some evidence that low endogenous testosterone levels may also be positively associated with cardiovascular events
  • effects of endogenous and exogenous testosterone may differ. Exogenous testosterone (TT) is associated with physiologic changes that predispose to clotting and thrombotic disorders including increased blood pressure [18], polycythemia [19], reductions in HDL cholesterol [18], [20], and hyperviscosity of the blood and platelet aggregation. [20]–[23]; TT also increases circulating estrogens [24], [25] which may play a role in the observed excess of adverse cardiovascular-related events, given that estrogen therapy has been associated with this excess in both men and women
  • did not include information on the serologic or diagnostic indications for treatment.
  • no association between PDE5I prescriptions and the risk of MI
  • Recently TT has been increasing extraordinarily rapidly, including among younger men and among those without hormone measurement
  • Nathan Goodyear on 30 Jan 14
     
    New cohort study finds increased risk of Testosterone in men > 65 and those : these are based in marketing-based medicine not evidence based medicine.
Nathan Goodyear

Waist-to-height ratio as a predictor of serum testosterone in ageing men with symptoms ... - 0 views

www.ncbi.nlm.nih.gov/...PMC3739344

waist to height ratio low T low testosterone aging Testosterone male hormones hormones men

shared by Nathan Goodyear on 19 Sep 16 - No Cached
  • WHt ratio was calculated by dividing waist (cm) by height (cm)
  • nverse relationships of BMI and WC with TT and cFT have been previously documented in unselected cohorts of adult men
  • over the age of 54 years
  • ...5 more annotations...
  • adjusting WC for height (WHt ratio) improves the prediction of TT and cFT compared with either BMI or WC alone
  • there were inverse correlations between cFT, TT and either BMI or WC
  • for each unit increase in BMI, there was a 2% fall in TT and cFT
  • for each 10 cm increment in WC, TT and cFT levels declined by 7%.
  • The magnitude of this relationship between increasing BMI and decreasing TT is similar to that described in the Massachusetts Male Ageing Study
  • Nathan Goodyear on 19 Sep 16
     
    waist to height ratio reliable predictor of low T in men.
Nathan Goodyear

Normalization of testosterone level is associated with reduced incidence of myocardial ... - 0 views

eurheartj.oxfordjournals.org/...eurheartj.ehv346

low T low Testosterone men Testosterone mortality stroke MI CVD cardiovascular disease hormones male

shared by Nathan Goodyear on 11 Aug 15 - No Cached
  • Normalized-TRT group had significantly fewer deaths than no-TRT
  • Mortality was also significantly lower in the non-normalized-TRT group compared with those in no-TRT group
  • the normalized-TRT group was associated with significantly increased all-cause mortality-free survival (log-rank, P < 0.05) compared with the non-normalized-TRT or no-TRT groups
  • ...10 more annotations...
  • normalized-TRT group showed lower risk of MI than non-normalized-TRT (HR: 0.82, CI 0.71–0.95, P = 0.008) and no-TRT
  • normalized-TRT group had significantly lower stroke events compared with non-normalized-TRT (HR: 0.70, CI 0.51–0.96, P = 0.028) and no-TRT
  • study of men with low TT levels and without prior MI or stroke, normalization of TT levels using TRT is associated with lower all-cause mortality, fewer MIs, and ischaemic strokes
  • retrospective study
  • the first study to demonstrate that significant benefit is observed only if the dose is adequate to normalize the TT levels
  • Patients who failed to achieve the therapeutic range after TRT did not see a reduction in MI or stroke and had significantly less benefit on mortality
  • selected patients without any previous history of MI or stroke prior to initiation of TRT to reduce bias related to CV outcomes
  • currently only half of the men on TRT had been diagnosed with hypogonadism.
  • 25% of users did not have their T concentrations tested prior to initiating therapy, and 21% of those prescribed TRT did not have their levels tested at any time during treatment.
  • men without a history of previous MI or stroke who have low TT levels, TRT might be associated with decreased risks of MI, ischaemic stroke, and all-cause mortality in long-term follow-up
  • Nathan Goodyear on 11 Aug 15
     
    Testosterone therapy in men with low T found to reduce all cause mortality, stroke and MI.
Nathan Goodyear

Normalization of testosterone level is associated with reduced incidence of myocardial ... - 0 views

eurheartj.oxfordjournals.org/...2706

low T low Testosterone Testosterone Testosterone therapy mortality MI stroke heart men male hormones

shared by Nathan Goodyear on 18 Jan 16 - No Cached
  • In this study of men with low TT levels and without prior MI or stroke, normalization of TT levels using TRT is associated with lower all-cause mortality, fewer MIs, and ischaemic strokes.
  • retrospective study
  • significant benefit is observed only if the dose is adequate to normalize the TT levels
  • ...9 more annotations...
  • the mechanisms for these effects remain speculative
  • It can be postulated that the beneficial effect of normal T levels on adipose tissue, insulin sensitivity, and lipid profiles or by its anti-inflammatory and anticoagulant properties, as reported by other investigators, might have contributed to our findings
  • off-label use of TRT remains a concern
  • Recent FDA analyses suggest that currently only half of the men on TRT had been diagnosed with hypogonadism
  • 25% of users did not have their T concentrations tested prior to initiating therapy
  • 21% of those prescribed TRT did not have their levels tested at any time during treatment
  • two very recent meta-analyses suggested a lack of convincing evidence posed by TRT.
  • men without a history of previous MI or stroke who have low TT levels, TRT might be associated with decreased risks of MI, ischaemic stroke, and all-cause mortality in long-term follow-up
  • TRT should aim for doses resulting in normalization of TT level as this was shown to be associated with reduction in adverse CV events
  • Nathan Goodyear on 18 Jan 16
     
    Testosterone therapy in men with low T to restore physiologic Testosterone levels found to reduce mortality, MI, and stroke risk.
Nathan Goodyear

Association of Free Testosterone With Hypogonadal Symptoms in Men With Near-normal Tota... - 0 views

www.ncbi.nlm.nih.gov/...26199166

low T low Testosterone Testosterone free Testosterone male hormones men

shared by Nathan Goodyear on 11 Aug 15 - No Cached
  • Nathan Goodyear on 11 Aug 15
     
    only abstract available here, but the authors conclude that free Testosterone is no associated with low T symptoms with near normal serum TT.  Not so fast, the study did find that free Testosterone did prove significant in younger men and this is exactly when the TT and fT appear to have significant discrepencies.
Nathan Goodyear

Is low testosterone concentration a risk factor for ... [Urology. 2013] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...24074976

metabolic syndrome metabolic syndrome MetS Testosterone male hormone hormones

shared by Nathan Goodyear on 08 Jan 14 - No Cached
  • Nathan Goodyear on 08 Jan 14
     
    Study of Japanese men > 30 found that lower serum TT was associated with an increased OR of metabolic syndrome.  The men in this study were "healthy".  This study looked at TT as a means to help predict MetS.
Nathan Goodyear

Low Levels of Free Testosterone Correlated wi... [Horm Metab Res. 2014] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...24867133

men male hormone hormones BMD free Testosterone Total low T

shared by Nathan Goodyear on 03 Jun 14 - No Cached
  • Nathan Goodyear on 03 Jun 14
     
    Interesting study looked at Total Testosterone (TT) and free Testosterone (FT) in older men in BMD assessment.  The authors found no change in TT, but a significant decline in free Testosterone.  This fits with other research pointing to free Testosterone as a better functional assessment tool.
Nathan Goodyear

Hypothalamic-Pituitary-Testicular Axis Disruptions in Older Men Are Differentially Link... - 0 views

press.endocrine.org/...jc.2007-1972

low T low Testosterone low T Testosterone aging LH hormone hormones men male SHBG

shared by Nathan Goodyear on 03 Sep 14 - No Cached
  • 0.4–2% annual decline
  • the age trend in free T was more substantial (−1.3% per annum)
  • The core hormonal pattern with increasing age is suggestive of incipient primary testicular dysfunction with maintained total T and progressively blunted free T associated with higher LH.
  • ...16 more annotations...
  • Obesity was associated with progressively lower total and free T independent of the simultaneous decrease in SHBG.
  • our data highlight the fact that LH was unchanged or even lower in older men in the face of lower T in obesity, suggesting that there may be a failure at the hypothalamic-pituitary level.
  • a change in BMI from nonobese to obese may be equivalent to a 15 yr fall in T.
  • This pattern supports the hypothesis that different underlying mechanisms influence the functions of the HPT axis: age predominantly affects testicular function, whereas obesity impairs hypothalamic/pituitary function.
  • the effects of aging on testicular function can be moderated by increased LH compensation for many decades
  • obesity impairs hypothalamic/pituitary function independent of age, arguably an adaptive response for which there should be no compensatory mechanism.
  • the concurrent but opposite (and separate) effects of obesity and age on SHBG
  • SHBG was negatively associated with increasing strata of obesity
  • Obesity is associated with insulin resistance (28), and the increased circulating insulin inhibits hepatic SHBG synthesis
  • the SHBG increase with age may be related to relative IGF-I deficiency (27), although this has not been directly proven.
  • Obesity is associated with peripheral and central insulin resistance (30) and proinflammatory cytokine production (TNFα and IL-6) from adipocytes (31) and central nervous system endocannibinoid release (32), all of which are potential candidates for abrogating hypothalamic endocrine and downstream reproductive axis functions.
    • Nathan Goodyear
      Nathan Goodyear on 03 Sep 14
       
      The HPA axis effect may be the result of inflammation.
  • The relationship between obesity and T can be bidirectional: low T may be the cause rather than consequence of obesity
  • chronic alcohol abuse is known to suppress LH (40), our data showed no significant association among the three hormones or SHBG and alcohol intake.
  • increase in total T in smokers occurs through a primary increase in SHBG with a compensatory rise in LH
  • the effects of obesity (BMI or waist circumference) was by far the most important determinant of variance in total T, whereas age per se was important for SHBG, LH, and free T with comorbidity and smoking being comparatively minor contributors
  • It is noteworthy that these predisposing lifestyle and health factors are modifiable. This implies that the apparent age-related decline in T may constitute a barometer of health and thus be potentially preventable and/or reversible.
  • Nathan Goodyear on 03 Sep 14
     
    Age induced decline in Testosterone is more associated with a decline in leydig cell function and thus elevated LH will be associated.  In contrast, obesity is more of a HPA axis disruption and thus LH may be normal to low.  The pulse amplitude is decrease.  No change in pulse frequency is noted.   With obesity, a decline in TT and fT was independent of SHBG. Aging is associated with a greater decrease in fT versus TT.
Nathan Goodyear

Total testosterone may not decline with ageing in Korean men aged 40 years or older. - ... - 0 views

www.ncbi.nlm.nih.gov/...22372615

total Testosterone ageing men male hormone hormones Testosterone glucose waist circumference BMI

shared by Nathan Goodyear on 01 Apr 15 - No Cached
  • Longitudinal change of TT was approximately + 0·8% per year.
  • TT was negatively correlated with body mass index (BMI), waist circumference and glucose
  • Nathan Goodyear on 01 Apr 15
     
    In study of 220 Korean mean, there was only a small decline in total Testosterone in men followed from 2002 to 2011.  The change amounted to 0.8% annually.  The level was 18.1 nmol to 17.8 nmol.  TT was inversely associated with BMI, waist and glucose.
Nathan Goodyear

Utility, Limitations, and Pitfalls in Measuring Testosterone: An Endocrine Society Posi... - 0 views

jcem.endojournals.org/...405.full

testosterone serum TT FT total free men male

shared by Nathan Goodyear on 17 Oct 12 - No Cached
  • Nathan Goodyear on 17 Oct 12
     
    This was a position statement from the Council of the Endocrine Society.  They looked at the reliability of free and total testosterone in serum and their conclusion: "...most assays for TT and FT are currently performed is decidedly unsatisfactory."  Enough said.  Interesting that they didn't look at salivary testosterone testing which has been shown to be extremely reliable and easy to perform.   I wonder how many physicians, insurance companies, state boards of medicine have read this statement?
Nathan Goodyear

Testosterone Deficiency, Cardiac Health, and Older Men - 0 views

www.hindawi.com/...143763

low T Testosterone obesity type II diabetes diabetes health wellness metabolic syndrome lipids cholesterol hypogonadism TDS testicular dysgenesis syndrome men male hormone hormones prostate cancer

shared by Nathan Goodyear on 12 May 14 - No Cached
  • Studies have shown pharmacological doses of testosterone to relax coronary arteries when injected intraluminally [39] and to produce modest but consistent improvement in exercise-induced angina and reverse associated ECG changes [40]. The mechanism of action is via blockade of calcium channels with effect of similar magnitude to nifedipine
    • Nathan Goodyear
      Nathan Goodyear on 12 May 14
       
      This directly refutes the recent studies (3) that Testosterone therapy increases cardiovascular events.
    • Nathan Goodyear
      Nathan Goodyear on 13 May 14
       
      Testosterone acts as a calcium channel blocker inducing vasodilation.
  • men with chronic stable angina pectoris, the ischaemic threshold increased after 4 weeks of TRT and a recent study demonstrates improvement continuing beyond 12 months [
  • Exercise capacity in men with chronic heart failure increased after 12 weeks
  • ...36 more annotations...
  • Studies have shown an inverse relationship between serum testosterone and fasting blood glucose and insulin levels
  • Medications such as chronic analgesics, anticonvulsants, 5ARIs, and androgen ablation therapy are associated with increased risk of testosterone deficiency and insulin resistance
  • Women with T2D or metabolic syndrome characteristically have low SHBG and high free testosterone
    • Nathan Goodyear
      Nathan Goodyear on 12 May 14
       
      This stands in polar opposite of that with men.
  • Hypogonadism is a common feature of the metabolic syndrome
  • The precise interaction between insulin resistance, visceral adiposity, and hypogonadism is, as yet, unclear but the important mechanisms are through increased aromatase production, raised leptin levels, and increase in inflammatory kinins
  • levels of testosterone are reduced in proportion to degree of obesity
  • Men should be encouraged to combine aerobic exercise with strength training. As muscle increases, glucose will be burned more efficiently and insulin levels will fall. A minimum of 30 minutes exercise three times weekly should be advised
  • Testosterone increases levels of fast-twitch muscle fibres
  • By increasing testosterone, levels of type 2 fibres increase and glucose burning improves
  • Weight loss will increase levels of testosterone
  • studies now clearly show that low testosterone leads to visceral obesity and metabolic syndrome and is also a consequence of obesity
  • In the case of MMAS [43], a baseline total testosterone of less than 10.4 nmol/L was associated with a greater than 4-fold incidence of type 2 diabetes over the next 9 years
  • There is high level evidence that TRT improves insulin resistance
  • Low testosterone predicts increased mortality and testosterone therapy improves survival in 587 men with type 2 diabetes
  • A similar retrospective US study involved 1031 men with 372 on TRT. The cumulative mortality was 21% in the untreated group versus 10% ( ) in the treated group with the greatest effect in younger men and those with type 2 diabetes
  • the presence of ED has been shown to be an independent risk factor, particularly in hypogonadal men, increasing the risk of cardiac events by over 50%
  • A recent online publication on ischaemic heart disease mortality in men concluded optimal androgen levels are a biomarker for survival
  • inverse associations between low TT or FT (Table 2) and the severity of CAD
  • A recent 10 year study from Western Australia involving 3690 men followed up from 2001–2010 concluded that TT and FT levels in the normal range were associated with decreased all-cause and cardiovascular mortality, for the first time suggesting that both low and DHT are associated with all-cause mortality and higher levels of DHT reduced cardiovascular risk
  • TDS is associated with increased cardiovascular and all-cause mortality
  • The effect of treatment with TRT reduced the mortality rate of treated cohort (8.4%) to that of the eugonadal group whereas the mortality for the untreated remained high at 19.2%
  • hypogonadal men had slightly increased triglycerides and HDL
  • Men with angiographically proven CAD (coronary artery disease) have significantly lower testosterone levels [29] compared to controls ( ) and there was a significant inverse relationship between the degree of CAD and TT (total testosterone) levels
  • TRT has also been shown to reduce fibrinogen to levels similar to fibrates
  • men treated with long acting testosterone showed highly significant reductions in TC, LDL, and triglycerides with increase in HDL, associated with significant reduction in weight, BMI, and visceral fat
  • Low androgen levels are associated with an increase in inflammatory markers
  • A decline was noted in IL6 and TNF-alpha
  • In some studies, a decline in diastolic blood pressure has been observed, after 3–9 months [24, 26] and in systolic blood pressure
  • In the Moscow study, C-reactive protein was reduced by TRT at 30 weeks versus placebo
  • No studies to date show an increase in LUTS/BPH symptoms with higher serum testosterone levels
  • TRT has been shown to upregulate PDE5 [65] and enhance the effect of PDE5Is (now an accepted therapy for both ED and LUTS), it no longer seems logical to advice avoidance of TRT in men with mild to moderate BPH.
    • Nathan Goodyear
      Nathan Goodyear on 12 May 14
       
      What about just starting with normalization of Testosterone levels first.
  • Several meta-analyses have failed to show a link between TRT and development of prostate cancer [66] but some studies have shown a tendency for more aggressive prostate cancer in men with low testosterone
    • Nathan Goodyear
      Nathan Goodyear on 12 May 14
       
      And if one would have looked at their estrogen levels, I guarantee they would have been found to be elevated.
  • low bioavailable testosterone and high SHBG were associated with a 4.9- and 3.2-fold risk of positive biopsy
  • Current EAU, ISSAM, and BSSM guidance [1, 2] is that there is “no evidence TRT is associated with increased risk of prostate cancer or activation of subclinical cancer.”
  • Men with prostate cancer, treated with androgen deprivation, develop an increase of fat mass with an altered lipid profile
  • Erectile dysfunction is an established marker for future cardiovascular risk and the major presenting symptom leading to a diagnosis of low testosterone
Nathan Goodyear

Relationship between Low Free Testosterone Levels and Loss of Muscle Mass : Scientific ... - 0 views

www.nature.com/...srep01818.html

muscle men male hormone Testosterone free Testosterone low T low Testosterone

shared by Nathan Goodyear on 05 Mar 15 - No Cached
  • Our data confirm that a low FT level is a significant predictor of a risk for loss of appendicular muscle
  • Total lean mass is associated with bioavailable T in postmenopausal women
  • Further studies are needed to determine the role of androgens in preserving muscle mass in women
  • ...11 more annotations...
  • Approximately 1% to 2% of T in the blood exists as FT
  • appendicular muscle loss was significantly associated with low levels of FT
  • These results suggest that a threshold level of FT exists for muscle loss, rather than a dose-response relationship
  • In the previous cross-sectional and longitudinal studies of French and American men, no dose-response relationships were reported between T and muscle mass
  • A minimal serum level of FT may be needed to preserve muscle mass in men, regardless of race/ethnicity.
  • Our result is in line with previous studies that reported a relationship between low FT and low muscle mass in men
  • T stimulates protein synthesis and inhibits protein degradation in muscle cells
  • T also increases satellite cell replication and activation in older men
  • In this study, no significant association between TT levels and muscle loss were observed
  • Although a progressive decrease in TT levels with ageing is observed in middle-aged and elderly American men16, 17, the TT levels do not change during ageing in Japanese men
  • FT levels may be a good marker for the loss of muscle mas
  • Nathan Goodyear on 05 Mar 15
     
    study of Japanese men finds that low free Testosterone was a predictor of decrease in muscle mass.
Nathan Goodyear

Calculated free testosterone and radioimmunoassay free testosterone as a predictor of s... - 0 views

www.ncbi.nlm.nih.gov/...21997201

low T low Testosterone Testosterone male hormones men hormones

shared by Nathan Goodyear on 19 Sep 16 - No Cached
  • Nathan Goodyear on 19 Sep 16
     
    In this study, calculated low free Testosterone correlated better with TT than radioimmunoassay free Testosterone.
Nathan Goodyear

Young Men With Poor Cardiorespi... [Int J Sport Nutr Exerc Metab. 2013] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...24413446

oxidized LDL oxidized LDL low T Testosterone men male hormone hormones

shared by Nathan Goodyear on 17 Jan 14 - No Cached
  • Nathan Goodyear on 17 Jan 14
     
    Low physical activity and low TT in men associated with oxidized LDL.
Nathan Goodyear

Longitudinal and cross-sectional rel... [J Clin Endocrinol Metab. 2014] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...24552220

low T Testosterone elderly men E1 Estrone health male hormone hormones men's health

shared by Nathan Goodyear on 24 Feb 14 - No Cached
  • Nathan Goodyear on 24 Feb 14
     
    This study found that lower TT and E1 associated with more "poor health" as defined by questionnaire.  The conclusion might lead one to think that Estrogen therapy is need in men.  Eightly percent of estrogen production in men occurs from Testosterone.  If Testosterone declines, then estrogen production will likewise decline.  A simple fact that the authors did not comment on.  Also, E1 binds with high affinity to ER alpha, which is pro-inflammatory and pro-proliferative: neither of which is a positive health benefit.   This appears to point more to a broad HPA suppression as an association to the "poor health".
Nathan Goodyear

Plasma testosterone in the general population, cancer prognosis and cancer risk: a pros... - 0 views

annonc.oxfordjournals.org/...712.abstract

cancer total testosterone mortality hormone hormones

shared by Nathan Goodyear on 02 Mar 14 - No Cached
  • Nathan Goodyear on 02 Mar 14
     
    Interesting prospective study on Total Testosterone.  If cancer is diagnosed, mortality is higher when TT is higher.  No change on incidence of cancer.  This study looked at men and women.  
Nathan Goodyear

Testosterone Treatment and Mortality in Men with Low Testosterone Levels - 0 views

jcem.endojournals.org/...2050.long

low T Testosterone mortality men male hormone hormones

shared by Nathan Goodyear on 15 Nov 13 - No Cached
  • Nathan Goodyear on 15 Nov 13
     
    In men with low T as defined by serum TT < 250 ng/dl, Testosterone therapy was found to provide a 39% reduction in mortality.  That is profound!
Nathan Goodyear

Effect of metoclopramide--a dopaminergic blocker a... [Acta Endocrinol (Copenh). 1985] ... - 0 views

www.ncbi.nlm.nih.gov/...4002999

cortisol T4 T3 rT3

shared by Nathan Goodyear on 14 Mar 11 - No Cached
  • High levels of cortisol may be responsible for the altered TT4 peripheral metabolism to TT3 and rT3 in these patients.
  • Nathan Goodyear on 14 Mar 11
     
    elevated cortisol blocks T4 to T3 conversion and increases rT3 production
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.
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