Skip to main content

Home/ Dr. Goodyear/ Group items tagged bioavailable Testosterone

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
Nathan Goodyear

Testosterone Levels and Sexual Function Disorders ... [J Sex Med. 2013] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...24286389

testosterone women depression antidepressants

shared by Nathan Goodyear on 02 Dec 13 - No Cached
  • Nathan Goodyear on 02 Dec 13
     
    Interesting finding in this study. They looked at Total Testosterone and bioavailable Testosterone and found that antidepressant therapy increased both values post treatment.  This is counter to what has been readably seen in men--with a decline.  The abstract here does not point disclose the actual Testosterone numbers.  I wonder if the well known disruption of the CYP enzymes by antidepressants slowed clearance and increased Testosterone levels.  This study did not look at other hormones or inflammatory cytokines.  Very tunneled vision study.  Nothing can be drawn from this study.
Nathan Goodyear

Relationship of serum sex steroid levels and bone turnover markers with bone mineral de... - 0 views

www.ncbi.nlm.nih.gov/...0009661593

total Testosterone bioavailable Testosterone hormone hormones

shared by Nathan Goodyear on 05 Apr 15 - No Cached
  • Nathan Goodyear on 05 Apr 15
     
    Total Testosterone in men decreased by 30% over the lifetime of men in this study compared to 64% decrease in bioavailable Testosterone in men.  Decreased BMD was associated with this loss.  Similar findings for Estrogen was also noted in men.
Nathan Goodyear

Serum testosterone improves the accuracy of Pro... [Clin Biochem. 2014] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...24530341

Testosterone prostate cancer

shared by Nathan Goodyear on 19 Feb 14 - No Cached
  • Nathan Goodyear on 19 Feb 14
     
    I think the authors missed the points to be taken from their research:prostate cancer patients had "lower concentrations of total Testosterone, free Testosterone, and bioavailable Testosterone" versus controls that were prostate cancer free.  This provides additional support that prostate cancer is not a androgen driven disease.
Nathan Goodyear

In Older Men an Optimal Plasma Testosterone Is Associated With Reduced All-Cause Mortal... - 0 views

jcem.endojournals.org/...jc.2013-3272.abstract

testosterone heart disease heart mortality DHT dihydrotestosterone estradiol male men hormone hormones

shared by Nathan Goodyear on 01 Dec 13 - No Cached
  • Nathan Goodyear on 01 Dec 13
     
    Older men, 70-89, Testosterone in the middle range of normal and higher DHT was associated with the lowest death rates.  Estradiol was not found to be associated.  This study only looked at Total levels, free bioavailable levels were not assessed.  This study also highlights the basic thought, that more is not always better as it pertains to Testosterone.  It also highlights the importance of DHT.  Testosterone is a pro hormone.
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

Transport of Steroid Hormones: Binding of 21 Endogenous Steroids to Both Testosterone-B... - 0 views

jcem.endojournals.org/...58.abstract

bioavailable free Testosterone hormones hormone transport

shared by Nathan Goodyear on 21 Nov 13 - No Cached
  • Nathan Goodyear on 21 Nov 13
     
    bioavailable Testosterone found to be approximately 30% of the total circulating Testosterone.  Only 1-3% of that percentage is unbound.  The other is bound to albumin.
Nathan Goodyear

Hypogonadal Symptoms Are Associated With Different S... [Urology. 2014] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...25288577

Testosterone total testosterone low T low T low Testosterone hypogonadism men male hormone hormones

shared by Nathan Goodyear on 08 Oct 14 - No Cached
  • Nathan Goodyear on 08 Oct 14
     
    This study looked at Total Testosterone and prevalence of low T symptoms.  As the authors stated, increased prevalence was found between 320 and 375 ng/dl.  Whereas, < 300 ng/dl was consistent with predictable low T symptoms.  It would have be more thorough if they had looked at salivary Testosterone levels and bioavailable as well.
Nathan Goodyear

Inverse relationship between serum levels of interleukin-1beta and testosterone in men ... - 0 views

www.researchgate.net/...stable_coronary_artery_disease

low T low T low Testosterone Testosterone inflammation men male hormone hormones IL-1beta IL-10 cytokines

shared by Nathan Goodyear on 13 Aug 14 - No Cached
  • Nathan Goodyear on 13 Aug 14
     
    low Total Testosterone and bioavailable Testosterone is associated with increased IL-1beta and IL-10.  This points to low T having a more direct link to increased systemic inflammation in men.
Nathan Goodyear

Metabolic syndrome, testosterone, and cardiovascular mortality in men. - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...21676188

low T low Testosterone bioavailable Testosterone cardiovascular disease metabolic syndrome mortality men male hormone hormones

shared by Nathan Goodyear on 04 Mar 15 - No Cached
  • Nathan Goodyear on 04 Mar 15
     
    study of 596 men finds that lower bioavailable Testosterone in those men with Metabolic Syndrome, have an increased cardiovascular mortality in those > 40.
Nathan Goodyear

Review of health risks of low testosterone and testosterone administration - 0 views

www.ncbi.nlm.nih.gov/...PMC4391003

low Testosterone low T Testosterone men male hormone hormones health

shared by Nathan Goodyear on 28 Apr 15 - No Cached
  • Hypogonadism may be defined either as serum concentration of T (either total T, bioavailable T or free T) or as low T plus symptoms of hypogonadism
  • The Baltimore Longitudinal Study on Aging reported the incidence of total serum T &lt; 325 ng/dL to be 20% for men in their 60s, 30% for men in their 70s and 50% for men over 80
  • The Massachusetts Aging Male Study reported that 12.3% of men aged 40 to 70 had a total serum T of &lt; 200 ng/dL with 3 or more symptoms of hypogonadism
  • ...19 more annotations...
  • The Boston Area Community Health Study reported that 5.6% of men aged 30 to 70 were hypogonadal, as defined by total serum T &lt; 300 ng/dL; or, free serum T &lt; 5 ng/dL plus 3 or more symptoms of hypogonadism
  • In a health screening project among 819 men in Taiwan, the prevalence of hypogonadism (total serum T &lt; 300 ng/dL) ranged from 16.5% for men in their 40s, 23.0% for men in their 50s, 28.9% for men in their 60s, and 37.2% for men older than 70 years of age
  • The prevalence of hypogonadism among men in Taiwan is higher than the prevalence reported in the Massachusetts Male Aging Study
  • CAG repeat sequence, within the androgen receptor (AR). Rajender et al[12] reviewed over 30 studies on the AR trinucleotide repeat and infertility
  • suggestion that CAG repeat length may determine androgen responsiveness, this issue is not clearly settled
  • reported prevalence of low T in older men range from 5.6% to 50%
  • Those in the hypogonadal group (n = 4269) had direct health care costs, that exceeded the eugonadal group (n = 4269) by an average of $7100 over the course of the observation window
  • higher economic burden and presence of co-morbidities for hypogonadism
  • minor to moderate improvements in lean mass and muscle strength
  • increased bone mineral density
  • modest enhancement in sexual function
  • reduced adiposity
  • lessening of depressive symptoms
  • Meta-analyses of clinical TRT trials as of 2010 have identified three major adverse events resulting from TRT: (1) polycythemia; (2) an increase in prostate-related events; and (3) and a slight reduction in serum high-density lipoprotein (HDL) cholesterol
  • polycythemia (&gt; 3.5-fold increase in risk
  • TRT produced a 40% prostate enlargement in older hypogonadal male Veterans over 12 mo
  • no published analysis has reported measurable increases in prostate cancer risk or Gleason score in men undergoing TRT, or in hypogonadal men with a history of prostate cancer undergoing TRT
  • the prostate which highly expresses the type II 5α-reductase enzyme. Inhibition of this enzyme via finasteride (a type II 5α-reductase inhibitor) or dutasteride (a dual type I and II 5α-reductase inhibitor) reduces circulating DHT 50%-75% and &gt; 90%, respectively[47], and reduces prostate mass[48] and prostate cancer risk
  • Normally estradiol partially regulates testosterone levels, at the hypothalamus, blunting LH and FSH release from the pituitary. As a selective estrogen receptor modulator, CC interrupts this pathway, and consequently there is a greater stimulation for the production of testosterone in Leydig cells
    • Nathan Goodyear
      Nathan Goodyear on 28 Apr 15
       
      this would only apply if E1 and/or E2 levels were elevated, which the authors make no mention of.
  • Nathan Goodyear on 28 Apr 15
     
    to be read
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 Hormones and Age: A Cross-sectional Study of Testosterone and Estradiol and Their B... - 0 views

aje.oxfordjournals.org/...750.short

hormone hormones men male Estradiol Estrogen testosterone

shared by Nathan Goodyear on 03 Feb 14 - No Cached
  • Nathan Goodyear on 03 Feb 14
     
    Older men have Estradiol levels that are 3 x that of a post-menopausal women.  The bioavailable levels of Testosterone and Estradiol showed the greatest precipitous decline.
Nathan Goodyear

Low serum testosterone and increased mortality in men with coronary heart disease -- Ma... - 0 views

heart.bmj.com/...1821.full

CAD cardiovascular low T Testosterone mortality bioavailable free heart disease heart

shared by Nathan Goodyear on 21 Nov 13 - No Cached
  • Nathan Goodyear on 21 Nov 13
     
    men with low bioavailable Testosterone associated with increased mortality in men with CAD.
Nathan Goodyear

Low Serum Testosterone and Mortality in Older Men - 0 views

jcem.endojournals.org/...68.full

Total Testosterone free bioavailable mortality men hormone hormones

shared by Nathan Goodyear on 21 Nov 13 - No Cached
  • Nathan Goodyear on 21 Nov 13
     
    men with the lowest Total and free, bioavailable Testosterone levels associated with the highest mortality rates.  This test looked at serum.
Nathan Goodyear

Endogenous Testosterone and Mortality in Men: A Systematic Review and Meta-Analysis - 0 views

jcem.endojournals.org/...3007.full

cardiovascular mortality low Testosterone T free bioavailable

shared by Nathan Goodyear on 21 Nov 13 - No Cached
  • Nathan Goodyear on 21 Nov 13
     
    low bioavailable "endogenous" Testosterone associated with increased cardiovascular mortality.
Nathan Goodyear

Transport of Steroid Hormones: Binding of 21 Endogenous Steroids to Both Testosterone-B... - 0 views

jcem.endojournals.org/...58.abstract

Testosterone hormone hormones albumin SHBG free bioavailable

shared by Nathan Goodyear on 12 Dec 13 - No Cached
  • Nathan Goodyear on 12 Dec 13
     
    Just the abstract here, but article discusses the various forms of Testosterone.  There is protein bound and inactive at apps 70%.  Free or bioavailable is at 2-4% with the remaining loosely bound to albumin.
Nathan Goodyear

Covariation of change in bioavailable testosterone and adiposity in... - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...25557490

Testosterone women female hormone hormones visceral fat abdominal fat menopause

shared by Nathan Goodyear on 29 Jan 15 - No Cached
  • Nathan Goodyear on 29 Jan 15
     
    Bioavailable Testosterone is positively associated with Visceral adipose tissue and to a lesser degree subcutaneous fat in women.  
Nathan Goodyear

Transport of steroid hormones: bindi... [J Clin Endocrinol Metab. 1981] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...7195404

testosterone saliva salivary hormone hormones aromatase SHBG estrogen men male

shared by Nathan Goodyear on 28 Aug 12 - No Cached
  • Nathan Goodyear on 28 Aug 12
     
    Increased aromatase activity in men increases testosterone to estrogen production, which causes increase in SHBG and thus a reduction in the bioavailability of free testosterone.  
Nathan Goodyear

http://press.endocrine.org/doi/pdf/10.1210/jc.2014-2934 - 0 views

press.endocrine.org/...jc.2014-2934

androgens hormone hormones cardiovascular disease CVD cardiovascular disease Testosterone DHEA dehydroepiandrosterone men women adipose tissue fat mass SHBG

shared by Nathan Goodyear on 02 Feb 15 - No Cached
  • Nathan Goodyear on 02 Feb 15
     
    Again, what is the evidence on androgens in women.  The majority of data is points to negative metabolic effects.  This study looked at men and women and found inverse relationships between Testosterone and DHEA in the sexes.  In women, higher bioavailable Testosterone and DHEA was associated with visceral and subcutaneous fat in women, where as the opposite is true in men.  In both men and women, higher SHBG was associated with lower fat.
Nathan Goodyear

Testosterone and pro-inflammatory cytokines in men with chronic heart failure - 0 views

www.endocrine-abstracts.org/...ea0003p250.htm

CHF congestive heart failure men male hormone hormones low T low t low Testosterone Testosterone IL-1beta TNF-alpha inflammation heart failure cardiovascular disease

shared by Nathan Goodyear on 13 Aug 14 - No Cached
  • Nathan Goodyear on 13 Aug 14
     
    Low bioavailable Testosterone associated with increased IL-1beta and TNF-alpha in men with CHF.
‹ Previous 21 - 40 of 53 Next ›
Showing 20▼ items per page