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Nathan Goodyear

Lowered testosterone in male obesity: Mechanisms, morbidity and management Tang Fui MN,... - 0 views

www.ajandrology.com/article.asp

Testosterone male obesity overweight men hormone hormones low T Low T

shared by Nathan Goodyear on 15 Jan 14 - No Cached
  • The number of overweight people is expected to increase from 937 million in 2005 to 1.35 billion in 2030
  • Similarly the number of obese people is projected to increase from 396 million in 2005 to 573 million in 2030
  • By 2030, China alone is predicted to have more overweight men and women than the traditional market economies combined
  • ...37 more annotations...
  • diacylglycerol O-acyltransferase 2 (DGAT2), mechanistically implicated in this differential storage, [10] is regulated by dihydrotestosterone, [11] suggesting a potential role for androgens to influence the genetic predisposition to either the MHO or MONW phenotype.
  • bariatric surgery achieves 10%-30% long-term weight loss in controlled studies
  • The fact that obese men have lower testosterone compared to lean men has been recognized for more than 30 years
  • Reductions in testosterone levels correlate with the severity of obesity and men
  • epidemiological data suggest that the single most powerful predictor of low testosterone is obesity, and that obesity is a major contributor of the age-associated decline in testosterone levels.
  • healthy ageing by itself is uncommonly associated with marked reductions in testosterone levels
  • obesity blunts this LH rise, obesity leads to hypothalamic-pituitary suppression irrespective of age which cannot be compensated for by physiological mechanisms
  • Reductions in total testosterone levels are largely a consequence of reductions in sex hormone binding globulin (SHBG) due to obesity-associated hyperinsulinemia
  • although controversial, measurement of free testosterone levels may provide a more accurate assessment of androgen status than the (usually preferred) measurement of total testosterone in situations where SHBG levels are outside the reference range
  • SHBG increases with age
  • marked obesity however is associated with an unequivocal reduction of free testosterone levels, where LH and follicle stimulating hormone (FSH) levels are usually low or inappropriately normal, suggesting that the dominant suppression occurs at the hypothalamic-pituitary level
  • adipose tissue, especially when in the inflamed, insulin-resistant state, expresses aromatase which converts testosterone to estradiol (E 2 ). Adipose E 2 in turn may feedback negatively to decrease pituitary gonadotropin secretion
  • diabetic obesity is associated with decreases in circulatory E 2
  • In addition to E 2 , increased visceral fat also releases increased amounts of pro-inflammatory cytokines, insulin and leptin; all of which may inhibit the activity of the HPT axis at multiple levels
  • In the prospective Massachusetts Male Aging Study (MMAS), moving from a non-obese to an obese state resulted in a decline of testosterone levels
  • weight loss, whether by diet or surgery, increases testosterone levels proportional to the amount of weight lost
  • fat is androgen-responsive
  • low testosterone may augment the effects of a hypercaloric diet
  • In human male ex vivo adipose tissue, testosterone decreased adipocyte differentiation by 50%.
  • Testosterone enhances catecholamine-induced lipolysis in vitro and reduces lipoprotein lipase activity and triglyceride uptake in human abdominal adipose tissue in vivo
  • in men with prostate cancer receiving 12 months of androgen deprivation therapy, fat mass increased by 3.4 kg and abdominal VAT by 22%, with the majority of these changes established within 6 months
  • severe sex steroid deficiency can increase fat mass rapidly
  • bidirectional relationship between testosterone and obesity
  • increasing body fat suppresses the HPT axis by multiple mechanisms [30] via increased secretion of pro-inflammatory cytokines, insulin resistance and diabetes; [19],[44] while on the other hand low testosterone promotes further accumulation of total and visceral fat mass, thereby exacerbating the gonadotropin inhibition
  • androgens may play a more significant role in VAT than SAT
  • men undergoing androgen depletion for prostate cancer show more marked increases in visceral compared to subcutaneous fat following treatment
    • Nathan Goodyear
      Nathan Goodyear on 16 Jan 14
       
      Interesting: low T increases VAT, yet T therapy does not reduce VAT, yet T therapy reduces SAT.
  • irisin, derived from muscle, induces brown fat-like properties in rodent white fat
  • androgens can act via the PPARg-pathway [37] which is implicated in the differentiation of precursor fat cells to the energy-consuming phenotype
  • low testosterone may compound the effect of increasing fat mass by making it more difficult for obese men to lose weight via exercise
  • pro-inflammatory cytokines released by adipose tissue may contribute to loss of muscle mass and function, leading to inactivity and further weight gain in a vicious cycle
  • Sarcopenic obesity, a phenotype recapitulated in men receiving ADT for prostate cancer, [55] may not only be associated with functional limitations, but also aggravate the metabolic risks of obesity;
  • observational evidence associating higher endogenous testosterone with reduced loss of muscle mass and crude measures of muscle function in men losing weight
  • genuine reactivation of the HPT axis in obese men requires more substantial weight-loss
  • A number of intervention studies have confirmed that both diet- and surgically-induced weight losses are associated with increased testosterone, with the rise in testosterone generally proportional to the amount of weight lost
  • men, regardless of obesity level, can benefit from the effect of weight loss.
  • inconsistent effect of testosterone on VAT
  • Nathan Goodyear on 15 Jan 14
     
    to be read
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

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

Sex steroids and cardiovascular disease Yeap BB - Asian J Androl - 0 views

www.ajandrology.com/article.asp

cardiovascular disease CVD sex estradiol carotid intima-media thickness hormones hormone men Testosterone estrogen

shared by Nathan Goodyear on 15 Jan 14 - No Cached
  • Levels of SHBG are higher in older men, therefore levels of free T decline more steeply than total T as men's age increases.
  • calculations based on mass action equations may not reflect precisely free T measured using a reference method
  • free T declines more steeply with age than total T in both cross-sectional [35] and longitudinal studies, [36] as does free E2 in comparison to total E2
  • ...22 more annotations...
  • T may slow development of or progression of atherosclerosis by modulating effects on insulin resistance, inflammation, endothelial function, preclinical atherosclerosis or the vasculature.
  • these cross-sectional and longitudinal studies support a relationship between low circulating T with CIMT and higher E2 with its progression
  • lower levels of T are biomarkers for aortic vascular disease
  • circulating free T was negatively associated with the presence of AAA
  • luteinizing hormone (LH) was positively associated.
  • low levels of total or bioavailable T were associated with aortic atherosclerosis manifested as calcified deposits detected by radiography
  • Men with total or free T in the lowest quartile had increased adjusted ORs for PAD defined as ABI <0.90, as did men with free E2 in the highest quartile of values
  • The apparent association of SHBG with intermittent claudication reflects the correlation of total T with SHBG, while the contribution of E2 to risk of PAD remains unclear
  • men with total T in the lowest quartile of values (<11.7 nmol l−1 ) experienced an increased incidence of stroke or transient ischemic attack
  • lower total T with increased incidence of CVD events
  • cohort studies in mostly older men have supported the association of lower androgen levels with higher mortality
  • lower total or free T levels were associated with mortality in older men, but with discordant results for cause-specific mortality and for associations of E2
  • several large studies identifying lower endogenous levels of total or free T as independent predictors of all-cause or CVD-related deaths in middle-aged and older men
  • T exhibits anti-inflammatory effects, enhances flow-mediated brachial artery reactivity, and reduces arterial stiffness
  • Short-term T therapy had a beneficial effect on exercise-induced myocardial ischemia in middle-aged men with coronary artery disease or chronic stable angina, [95],[96],[97] and reduced angina frequency in older men with diabetes and coronary artery disease
  • T therapy resulted in an increase in treadmill test duration and time to ST segment depression
  • there are interventional studies supporting a protective effect of exogenous T against myocardial ischemia in men with coronary artery disease
  • employ conservative doses
    • Nathan Goodyear
      Nathan Goodyear on 16 Jan 14
       
      This dosing is 100 fold higher then peak production of a  young man at 20-22.
  • Observational studies indicate that lower levels of endogenous T in older men are associated with the presence of carotid atherosclerosis, aortic and peripheral vascular disease, and incidence of CVD events and mortality
  • Interventional studies have shown beneficial effects of exogenous T on vascular function and on exercise-induced myocardial ischemia in men with coronary artery disease
    • Nathan Goodyear
      Nathan Goodyear on 16 Jan 14
       
      the therapies employed in these studies were massively overdosed.
  • Nathan Goodyear on 15 Jan 14
     
    Nice review of all the sex hormones and their relationship to CVD in men.  
Nathan Goodyear

Testosterone deficiency and cardiovascular mortality Morgentaler A, - Asian J Androl - 0 views

www.ajandrology.com/preprintarticle.asp

testosterone low t low Testosterone CVD cardiovascular mortality therapy

shared by Nathan Goodyear on 01 Dec 14 - No Cached
  • overall mortality and CV mortality were inversely associated with serum T concentrations.
  • men with low serum T, defined as < 8.7 nmol l−1 (250 ng dl−1 ), demonstrated significantly greater all-cause mortality than men with higher serum T (hazard ratio [HR]: 2.24; 95% CI: 1.41-3.57), as well as greater CV mortality
  • lower T levels were significantly associated with the presence of any CV disease
  • ...19 more annotations...
  • more than 30 years of studies suggesting that low levels of T represent an increased risk for CV and overall mortality,
  • lower serum T concentrations also are associated with CV disease, including incident coronary artery disease [17],[18],[19] and atherosclerosis,
  • the actual rate of adverse events was only half as great in the T group (123 events in 1223 men at risk = 10.1%) as in the untreated group (1587 events in 7486 men = 21.2%)
  • The study by Vigen et al. [7] has already undergone two published corrections,
  • 29 medical societies have called for retraction of the article, asserting "gross data mismanagement and contamination," that rendered the study "no longer credible
  • Mortality in T-treated men was reduced by approximately half in treated men compared with untreated men, at 10.3% versus 20.7%, respectively
  • The mortality rate for men who received TTh was 3.4 deaths per 100 person-years, and 5.7 deaths per 100 person-years in untreated men
  • HR of 0.61 (95%CI: 0.42-0.88; P = 0.008), indicating a significant reduction in mortality with TTh
  • men in the highest prognostic MI risk quartile, treatment with TTh was associated with reduced risk
  • tripling in T prescriptions in the US over the last decade
  • a majority of observational studies have found that low endogenous serum T levels are associated with increased mortality.
  • Men who received TTh were able to exercise significantly longer without ischemia compared with men who received placebo
  • In men with congestive heart failure, those who received T demonstrated greater walking distance and other functional endpoints compared with those who received placebo
  • TTh has been shown uniformly and repeatedly to improve several known CV risk factors, including reduced fat mass, body fat percent, and waist circumference, and increased lean mass
  • improved glycemic control
  • reductions in insulin resistance.
  • the evidence strongly points to improved CV status with normal serum T or treatment with TTh in men with TD
  • analysis of health insurance claims data that reported a 36% increased rate of nonfatal MI in the 90d following receipt of a T prescription compared with the 12 prior months.
  • Comparison with men who received a prescription for a phosphodiesterase type 5 inhibitor (PDE5i) revealed no increased rate of MI following the prescription
  • Nathan Goodyear on 01 Dec 14
     
    Great review by Morgentaler of Testosterone and CVD.  He highlights the significant flaws in the JAMA and the NEJM articles of Testosterone therapy risks.  Morgentaler highlights the significant evidence that points to low T and increased risk of CVD. On contention I have, is Morgantaler seems to flip aside the massive uptick of Testosterone use in the US as compared to other countries.  The evidence definitely points to Testosterone therapy as being safe in those with low T, but there is definitely a problem of significant Testosterone doping that is taking place as well.
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

Recovery after heavy resistance exercise... [J Strength Cond Res. 2011] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...21311349

recovery resistance exercise training resistance training Testosterone Total free men male hormone hormones

shared by Nathan Goodyear on 03 Sep 14 - No Cached
  • Nathan Goodyear on 03 Sep 14
     
    "Heavy resistance exercise" associated with acute increase in TT and fT in men.  No changes were see in basal T and fT in recovery or AR.  The recovery phase was estimated to take 6 days.
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

[Serum thyroid hormone levels correlate with cardi... [J Cardiol. 1993] - PubMed result - 0 views

www.ncbi.nlm.nih.gov/...8176632

hypothyroid hypothyroidism T3 T4 rT3 cardiovascular disease CHF tachycardia

shared by Nathan Goodyear on 01 Feb 11 - No Cached
  • Patients with ventricular tachycardia demonstrated significantly lower serum values of FT3 and FT3/FT4, and significantly higher values of rT3. Serum thyroid hormone levels can provide a quantitative index for evaluating the severity of chronic heart failure and predicting ventricular tachycardia.
  • Nathan Goodyear on 01 Feb 11
     
    Full thyroid evaluation, not TSH or just T4, is predictive in severity of CHF and heart tachycardia
Nathan Goodyear

Thyroid Replacement Therapy and Heart Failure - 0 views

circ.ahajournals.org/...385.full

thyroid T3 hormone hormones cardiovascular disease heart health failure CHF MI myocardial infarction heart attack heart disease

shared by Nathan Goodyear on 24 Sep 14 - No Cached
  • A good biomarker of intracardiac TH signaling would be helpful but has not been identified. In the absence of such a marker, a rational, cautious therapeutic approach might be to restore and maintain over time biochemical euthyroidism as documented by normal circulating levels of TSH, FT4, and FT3.
  • a low-T3 state resulting from altered peripheral TH metabolism secondary to caloric restriction is associated with impaired cardiac contractility
  • Low-T3 syndrome is the central finding and defines the illness in a variety of acute and chronic severe nonthyroidal illnesses with cardiac origin, including MI, HF, and surgically treated cardiac disease.1 Low circulating levels of T3 in the absence of primary thyroid hypofunction have been found in 20% to 30% of patients with dilated cardiomyopathy.
  • ...1 more annotation...
  • FT3 levels were inversely correlated to coronary artery disease
  • Nathan Goodyear on 24 Sep 14
     
    Great review of the current understanding of thyroid hormone metabolism in cardiac tissue.  Low T3 and increased rT3 (via increased D3 activity) is CLEARLY associated with poor cardiac performance and post MI and CHF is associated with poor outcomes.  T3 is critical in cardiac remodeling and recovery post MI.  T3 is actually a vasodilatory in the coronary arteries.   Why a endocrinologist would call rT3 useless only points to their ignorance of the literature.
Nathan Goodyear

Low testosterone is associated with poor health status in men with ... - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...25704864

low T Testosterone low Testosterone HIV fT3 poor health men male hormones hormone

shared by Nathan Goodyear on 02 Mar 15 - No Cached
  • Nathan Goodyear on 02 Mar 15
     
    Lower Testosterone levels are found in men with more advanced HIV.  This relationship is bidirectional.  This decreased biomarker is likely more a biomarker of poor health than one of a direct relationship.  As in the fT3 is lower in hypogonadal men versus eugonadal men.  This points to the significant problems in the way Testosterone is thought of and used in therapy for men today.  For many men, low T is the effect and not the cause.
Nathan Goodyear

Reverse T3 as a parameter of myocardial functi... [Int J Cardiol. 2010] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...19428128

thyroid hormone hormones reverse T3 fT3_rT3 rT3 heart failure CHF cardiovascular disease.

shared by Nathan Goodyear on 16 Aug 14 - No Cached
  • Nathan Goodyear on 16 Aug 14
     
    Another study regarding reverse T3 that many Endocrinologists need to read.  In this study, the authors find that significantly higher reverse T3 levels were associated with myocardial function impairment (MFI) class IV.  This MFI class IV was also found associated with a decreased fT3/rT3.
Nathan Goodyear

Testosterone and benign prostatic hyperplasia Jarvis TR, Chughtai B, Kaplan SA, - Asian... - 0 views

www.ajandrology.com/preprintarticle.asp

Testosterone BPH low T low Testosterone prostate cancer men male hormone hormones

shared by Nathan Goodyear on 01 Dec 14 - No Cached
  • The prevalence of hypogonadism (often defined as serum testosterone < 300 ng dl−1 ) ranges from 6% [10] to as high as 38%
  • The process of BPH, however, continues as men age and despite the fact their serum testosterone decreases
  • Liu et al. [12] demonstrated that in a group of older males (mean age 59.8 years) that there was not a significant correlation of serum testosterone levels (total, free or bioavailable) with either prostate volume or International Prostate Symptom Score (IPSS)
  • ...11 more annotations...
  • in eugonadal men, studies have demonstrated that the prostate can increase in volume by approximately 12%
  • There seems to be little doubt that the treatment with testosterone of a young hypogonadal male leads to significant growth of the prostate
  • Behre et al. [22] demonstrated increased prostate volume and prostate-specific antigen (PSA) levels in hypogonadal men
  • Most studies, however, have shown no effect of exogenous androgens on PSA or prostate volume for older hypogonadal males
  • They argue that the prostate is relatively insensitive to changes in androgen concentration at normal levels or in mild hypogonadism because the AR is saturated by androgens and therefore maximal androgen-AR binding is achieved. Conversely, the prostate is very sensitive to changes in androgen levels when testosterone is low
  • saturation model
  • visceral obesity (one of the most significant components of metabolic syndrome) is associated with prostate volume and influences prostate growth during TRT.
  • This hypothesis of inflammation induced LUTS is also argued to be a mechanism for improvement of LUTS with PDE5I
  • The concept, therefore, that treatment with TRT of hypogonadal males with metabolic syndrome might lead to improvement/stabilization of their LUTS, appears to be confirmed in recent work by Francomano et al.
  • There was also an improvement in components of the patient's metabolic syndrome (such as BMI, waist circumference, hemoglobin A1c [HbA1c], insulin sensitivity, and lipid profile) as well as inflammatory markers and C-reactive protein.
  • They concluded that TRT was safe in this group of men, and hypothesize that TRT mitigates the pro-inflammatory factors associated with metabolic syndrome.
  • Nathan Goodyear on 01 Dec 14
     
    Authors review the literature behind Testosterone and BPH.  The authors highlight the 4 proposed theories behind BPH: Testosterone, Estrogen, inflammation, and metabolic.   The conclusion is mixed: pointing out that no high level of evidence exists on either side of the debate of Testosterone and BPH.
Nathan Goodyear

To what extent are free testosterone (FT) values reproducible between the two Washingto... - 0 views

171.67.112.51/...459.full.pdf

testosterone hormone hormones SHBG free testosterone

shared by Nathan Goodyear on 16 Nov 12 - No Cached
  • Nathan Goodyear on 16 Nov 12
     
    Not that I am a proponent of calculations and estimations. I am a proponent of actual measurement ie. saliva. But this article does lay out some good basic, historical figures about testosterone and SHBG.
Nathan Goodyear

Testosterone responses to intensive inte... [J Endocrinol Invest. 2012] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...23310924

exercise high intensity training HIT hormone hormones Testosterone free 3-alpha androstanediol

shared by Nathan Goodyear on 27 Jan 14 - No Cached
  • Nathan Goodyear on 27 Jan 14
     
    high intensity interval training versus steady state provides different results in post exercise FT.
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
  • In the Moscow study, C-reactive protein was reduced by TRT at 30 weeks versus placebo
  • In some studies, a decline in diastolic blood pressure has been observed, after 3–9 months [24, 26] and in systolic blood pressure
  • A decline was noted in IL6 and TNF-alpha
  • 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

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

Free triiodothyronine: a novel predictor of postoperative atrial fibrillation -- Cerill... - 0 views

ejcts.ctsnetjournals.org/...487

triiodothyronine free T3 atrial fibrillation CABG cardiovascular disease

shared by Nathan Goodyear on 01 Feb 11 - No Cached
  • Nathan Goodyear on 01 Feb 11
     
    Conclusions: Low basal fT3 concentration can reliably predict the occurrence of postoperative Atrial Fibrillation in Coronary-bypass patients
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.
snfilms

Tere Bin Ek Pal - 0 views

Hindi Hindi music videos #SadSong Sn films #TereBinEkPal Romanticsad Aa #ProductionHouseHooghly

shared by snfilms on 18 Jul 20 - No Cached
  • snfilms on 18 Jul 20
     
    Check out Debasmita Chattopadhyay ft. Sanjib Nath reprised version of तेरे बिन एक पल from the movie #AaAbLautChalen https://youtu.be/an_lOoXjx7o #Hindi #SadSong #TereBinEkPal #RomanticSadSong #snfilms #AaAbLautChalen #ProductionHouseHooghly #HindiMusicVideos
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