Skip to main content

Home/ Dr. Goodyear/ Group items tagged bone mineral density

Rss Feed Group items tagged

Nathan Goodyear

High aromatase activity in hypogonadal men is associated with higher spine bone mineral... - 0 views

  •  
    Only abstract available here--high Estradiol:Testosterone, thus high aromatase activity, increased abdominal fat and reduced lean muscle mass.  The authors also reported an higher bone mineral density, but that pales in the comparison of the metabolic dysfunction of high fat and low muscle mass causes.
Nathan Goodyear

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

  • 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
       
      FAI: 100 x total Testosterone nmol/L/SHBG nmol/L
    • Nathan Goodyear
       
      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
       
      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
  •  
    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

Comparison of Sex Steroid Measurements in Men by Immunoassay versus Mass Spectroscopy a... - 0 views

  •  
    Mass Spectroscopy proves to be better test, specifically specificity, in men due to low Estradiol levels.  This study compared MS to Immunoassay.
Nathan Goodyear

Effects of dietary calcium compared with calcium supplements on estrogen metabolism and... - 0 views

  •  
    dietary calcium proves to be better source than Calcium supplement
Nathan Goodyear

The association between serum dehydroepiandrosterone sulfate (DHEA-... - PubMed - NCBI - 0 views

  •  
    Only abstract available here, but lower DHEA-S (still in reference normal range) associated with lower bone mineral density and increased osteoporosis risk.
Nathan Goodyear

JAMA Network | Archives of Internal Medicine | Plasma Total Homocysteine Level and Bone... - 0 views

  •  
    elevated homocysteine and low folic acid levels associated with decreasing BMD in women.
Nathan Goodyear

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

  • 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 < 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 < 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 < 300 ng/dL; or, free serum T < 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 < 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 (> 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 > 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
       
      this would only apply if E1 and/or E2 levels were elevated, which the authors make no mention of.
  •  
    to be read
Nathan Goodyear

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

  •  
    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

Testosterone for the aging male; current evidence and recommended practice - 0 views

  • Total serum testosterone consists of free testosterone (2%–3%), testosterone bound to sex hormone binding globulin (SHBG) (45%) and testosterone bound to other proteins (mainly albumin −50%)
  • Testosterone binds only loosely to albumin and so this testosterone as well as free testosterone is available to tissues and is termed bioavailable testosterone
  • Testosterone bound to SHBG is tightly bound and is biologically inactive
  • ...13 more annotations...
  • Bioavailable and free testosterone are known to correlate better than total testosterone with clinical sequelae of androgenization such as bone mineral density and muscle strength
  • peak levels seen in the morning following sleep, which can be maintained into the seventh decade
  • Samples should always be taken in the morning before 11 am
  • The reliable measurement of serum free testosterone requires equilibrium dialysis. This is not appropriate for clinical use as it is very time consuming and therefore expensive.
  • With increasing age, a greater number of men have total testosterone levels just below the normal range or in the low-normal range. In these patients total testosterone can be an unreliable indicator of hypogonadal status.
  • It is advised that at least two serum testosterone measurements, taken before 11 am on different mornings, are necessary to confirm the diagnosis.
  • Patients with serum total testosterone consistently below 8 nmol/l invariably demonstrate the clinical syndrome of hypogonadism and are likely to benefit from treatment. Patients with serum total testosterone in the range 8–12 nmol/l often have symptoms attributable to hypogonadism and it may be decided to offer either a clinical trial of testosterone treatment or to make further efforts to define serum bioavailable or free testosterone and then reconsider treatment. Patients with serum total testosterone persistently above 12 nmol/l do not have hypogonadism and symptoms are likely to be due to other disease states or ageing per se so testosterone treatment is not indicated.
  • Total testosterone levels fall at an average of 1.6% per year whilst free and bioavailable levels fall by 2%–3% per year.
  • With advancing age there is also a reduction in androgen receptor concentration in some target tissues and this may contribute to the clinical syndrome of LOH
  • Metabolic clearance declines with age
  • Gonadotrophin levels rise during aging (Feldman et al 2002) and testicular secretory responses to recombinant human chorionic gonadotrophin (hCG) are reduced
  • There are changes in the lutenising hormone (LH) production which consist of decreased LH pulse frequency and amplitude, (Veldhuis et al 1992; Pincus et al 1997) although pituitary production of LH in response to pharmacological stimulation with exogenous GnRH analogues is preserved
  • the decreases in testosterone levels with aging seem to reflect changes at all levels of the hypothalamic-pituitary-testicular axis
  •  
    Leptin inhibits male Testosterone production at the level of the hypothalamus and at the testicle level.
Nathan Goodyear

Effects of aromatase inhibition vs. testosterone in older men with low testosterone: ra... - 0 views

  •  
    No surprise that Testosterone therapy improves Testosterone levels in men with low T, but aromatase inhibition (AI) did as well.  In this study, only lean mass increased compared to Testosterone therapy and placebo.  Strength increased in both Testosterone and AI.
1 - 10 of 10
Showing 20 items per page