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Nathan Goodyear

The Effect of High-Intensity Intermittent Exercise on Body Composition of Overweight Yo... - 0 views

www.hindawi.com/...480467

HIT high intensity intermittent training high intensity training exercise obesity weight-loss training overweight

shared by Nathan Goodyear on 13 Jul 12 - No Cached
  • Nathan Goodyear on 13 Jul 12
     
    High intensity training results in effective fat loss.  This study followed individuals over a 12 week cycle.  They performed HIT at 20 mins 3 x weekly.  Fat loss was statistically significant when compared to control group.
Nathan Goodyear

Molecules | Free Full-Text | The Chemical Composition and Biological Properties of Coco... - 0 views

www.mdpi.com/5144

coconut water

shared by Nathan Goodyear on 27 Nov 11 - No Cached
  • Nathan Goodyear on 27 Nov 11
     
    many health benefits of coconut water
Nathan Goodyear

The Effect of High-Intensity Intermittent Exercise on Body Composition of Overweight Yo... - 0 views

www.ncbi.nlm.nih.gov/...PMC3375095

high intensity interval training HIT HIIE exercise wieght-loss overweight obesity

shared by Nathan Goodyear on 27 Jul 12 - No Cached
  • Nathan Goodyear on 27 Jul 12
     
    another study that shows that High intensity interval training (HIT) results in fat loss.  IN this study, training consisted of 20 minutes 3 x weekly for 12 weeks.  Fat loss in total, abdominal, trunk, and visceral was decreased.  This study only looked at men.
Nathan Goodyear

The Relationships Between Testosterone, Body Composition, and Insulin Resistance - 0 views

care.diabetesjournals.org/...429.full

women female weight-gain obesity weight loss insulin resistance insulin resistance

shared by Nathan Goodyear on 20 Jun 12 - No Cached
  • Nathan Goodyear on 20 Jun 12
     
    case study that showed removal of testosterone secreting adrenal tumor worsened insulin function and contributed to weight gain 9 months post surgery.  This is a case study and far from conclusive.
Nathan Goodyear

Testosterone and glucose metabolism in men: current concepts and controversies - 0 views

joe.endocrinology-journals.org/...R37.full

Low T Testosterone metabolic syndrome MetS Diabetes men male glucose hormone hormones g

shared by Nathan Goodyear on 04 Feb 14 - No Cached
  • Around 50% of ageing, obese men presenting to the diabetes clinic have lowered testosterone levels relative to reference ranges based on healthy young men
  • The absence of high-level evidence in this area is illustrated by the Endocrine Society testosterone therapy in men with androgen deficiency clinical practice guidelines (Bhasin et al. 2010), which are appropriate for, but not specific to men with metabolic disorders. All 32 recommendations made in these guidelines are based on either very low or low quality evidence.
  • A key concept relates to making a distinction between replacement and pharmacological testosterone therapy
  • ...59 more annotations...
  • The presence of symptoms was more closely linked to increasing age than to testosterone levels
  • Findings similar to type 2 diabetes were reported for men with the metabolic syndrome, which were associated with reductions in total testosterone of −2.2 nmol/l (95% CI −2.41 to 1.94) and in free testosterone
  • low testosterone is more predictive of the metabolic syndrome in lean men
  • Cross-sectional studies uniformly show that 30–50% of men with type 2 diabetes have lowered circulating testosterone levels, relative to references based on healthy young men
  • In a recent cross-sectional study of 240 middle-aged men (mean age 54 years) with either type 2 diabetes, type 1 diabetes or without diabetes (Ng Tang Fui et al. 2013b), increasing BMI and age were dominant drivers of low total and free testosterone respectively.
  • both diabetes and the metabolic syndrome are associated with a modest reduction in testosterone, in magnitude comparable with the effect of 10 years of ageing
  • In a cross-sectional study of 490 men with type 2 diabetes, there was a strong independent association of low testosterone with anaemia
  • In men, low testosterone is a marker of poor health, and may improve our ability to predict risk
    • Nathan Goodyear
      Nathan Goodyear on 04 Feb 14
       
      probably the most important point made in this article
  • low testosterone identifies men with an adverse metabolic phenotype
  • Diabetic men with low testosterone are significantly more likely to be obese or insulin resistant
  • increased inflammation, evidenced by higher CRP levels
  • Bioavailable but not free testosterone was independently predictive of mortality
  • It remains possible that low testosterone is a consequence of insulin resistance, or simply a biomarker, co-existing because of in-common risk factors.
  • In prospective studies, reviewed in detail elsewhere (Grossmann et al. 2010) the inverse association of low testosterone with metabolic syndrome or diabetes is less consistent for free testosterone compared with total testosterone
  • In a study from the Framingham cohort, SHBG but not testosterone was prospectively and independently associated with incident metabolic syndrome
  • low SHBG (Ding et al. 2009) but not testosterone (Haring et al. 2013) with an increased risk of future diabetes
  • In cross-sectional studies of men with (Grossmann et al. 2008) and without (Bonnet et al. 2013) diabetes, SHBG but not testosterone was inversely associated with worse glycaemic control
  • SHBG may have biological actions beyond serving as a carrier protein for and regulator of circulating sex steroids
  • In men with diabetes, free testosterone, if measured by gold standard equilibrium dialysis (Dhindsa et al. 2004), is reduced
    • Nathan Goodyear
      Nathan Goodyear on 04 Feb 14
       
      expensive, laborious process filled with variables
  • Low free testosterone remains inversely associated with insulin resistance, independent of SHBG (Grossmann et al. 2008). This suggests that the low testosterone–dysglycaemia association is not solely a consequence of low SHBG.
  • Experimental evidence reviewed below suggests that visceral adipose tissue is an important intermediate (rather than a confounder) in the inverse association of testosterone with insulin resistance and metabolic disorders.
  • testosterone promotes the commitment of pluripotent stem cells into the myogenic lineage and inhibits their differentiation into adipocytes
  • testosterone regulates the metabolic functions of mature adipocytes (Xu et al. 1991, Marin et al. 1995) and myocytes (Pitteloud et al. 2005) in ways that reduce insulin resistance.
  • Pre-clinical evidence (reviewed in Rao et al. (2013)) suggests that at the cellular level, testosterone may improve glucose metabolism by modulating the expression of the glucose-transported Glut4 and the insulin receptor, as well as by regulating key enzymes involved in glycolysis.
  • More recently testosterone has been shown to protect murine pancreatic β cells against glucotoxicity-induced apoptosis
  • Interestingly, a reciprocal feedback also appears to exist, given that not only chronic (Cameron et al. 1990, Allan 2013) but also, as shown more recently (Iranmanesh et al. 2012, Caronia et al. 2013), acute hyperglycaemia can lower testosterone levels.
  • There is also evidence that testosterone regulates insulin sensitivity directly and acutely
  • In men with prostate cancer commencing androgen deprivation therapy, both total as well as, although not in all studies (Smith 2004), visceral fat mass increases (Hamilton et al. 2011) within 3 months
  • More prolonged (>12 months) androgen deprivation therapy has been associated with increased risk of diabetes in several large observational registry studies
  • Testosterone has also been shown to reduce the concentration of pro-inflammatory cytokines in some, but not all studies, reviewed recently in Kelly & Jones (2013). It is not know whether this effect is independent of testosterone-induced changes in body composition.
  • the observations discussed in this section suggest that it is the decrease in testosterone that causes insulin resistance and diabetes. One important caveat remains: the strongest evidence that low testosterone is the cause rather than consequence of insulin resistance comes from men with prostate cancer (Grossmann & Zajac 2011a) or biochemical castration, and from mice lacking the androgen receptor.
  • Several large prospective studies have shown that weight gain or development of type 2 diabetes is major drivers of the age-related decline in testosterone levels
  • there is increasing evidence that healthy ageing by itself is generally not associated with marked reductions in testosterone
  • Circulating testosterone, on an average 30%, is lower in obese compared with lean men
  • increased visceral fat is an important component in the association of low testosterone and insulin resistance
  • The vast majority of men with metabolic disorders have functional gonadal axis suppression with modest reductions in testosterone levels
  • obesity is a dominant risk factor
  • men with Klinefelter syndrome have an increased risk of metabolic disorders. Interestingly, greater body fat mass is already present before puberty
  • Only 5% of men with type 2 diabetes have elevated LH levels
  • inhibition of the gonadal axis predominantly takes place in the hypothalamus, especially with more severe obesity
  • Metabolic factors, such as leptin, insulin (via deficiency or resistance) and ghrelin are believed to act at the ventromedial and arcuate nuclei of the hypothalamus to inhibit gonadotropin-releasing hormone (GNRH) secretion from GNRH neurons situated in the preoptic area
  • kisspeptin has emerged as one of the most potent secretagogues of GNRH release
  • hypothesis that obesity-mediated inhibition of kisspeptin signalling contributes to the suppression of the HPT axis, infusion of a bioactive kisspeptin fragment has been recently shown to robustly increase LH pulsatility, LH levels and circulating testosterone in hypotestosteronaemic men with type 2 diabetes
  • A smaller study with a similar experimental design found that acute testosterone withdrawal reduced insulin sensitivity independent of body weight, whereas oestradiol withdrawal had no effects
  • suppression of the diabesity-associated HPT axis is functional, and may hence be reversible
  • Obesity and dysglycaemia and associated comorbidities such as obstructive sleep apnoea (Hoyos et al. 2012b) are important contributors to the suppression of the HPT axis
  • weight gain and development of diabetes accelerate the age-related decline in testosterone
  • Modifiable risk factors such as obesity and co-morbidities are more strongly associated with a decline in circulating testosterone levels than age alone
  • 55% of symptomatic androgen deficiency reverted to a normal testosterone or an asymptomatic state after 8-year follow-up, suggesting that androgen deficiency is not a stable state
  • Weight loss can reactivate the hypothalamic–pituitary–testicular axis
  • Leptin treatment resolves hypogonadism in leptin-deficient men
  • The hypothalamic–pituitary–testicular axis remains responsive to treatment with aromatase inhibitors or selective oestrogen receptor modulators in obese men
  • Kisspeptin treatment increases LH secretion, pulse frequency and circulating testosterone levels in hypotestosteronaemic men with type 2 diabetes
  • change in BMI was associated with the change in testosterone (Corona et al. 2013a,b).
  • weight loss can lead to genuine reactivation of the gonadal axis by reversal of obesity-associated hypothalamic suppression
  • There is pre-clinical and observational evidence that chronic hyperglycaemia can inhibit the HPT axis
  • in men who improved their glycaemic control over time, testosterone levels increased. By contrast, in those men in whom glycaemic control worsened, testosterone decreased
  • testosterone levels should be measured after successful weight loss to identify men with an insufficient rise in their testosterone levels. Such men may have HPT axis pathology unrelated to their obesity, which will require appropriate evaluation and management.
  • Nathan Goodyear on 04 Feb 14
     
    Article discusses the expanding evidence of low T and Metabolic syndrome.
Nathan Goodyear

Testosterone and glucose metabolism in men: current concepts and controversies - 0 views

joe.endocrinology-journals.org/...R37.full

shared by Nathan Goodyear on 04 Feb 14 - No Cached
    • Nathan Goodyear
      Nathan Goodyear on 04 Feb 14
       
      80% of E2 production in men, that will cause low T in men, comes from SQ adiposity.  This leads to increase in visceral adiposity.
  • Only 5% of men with type 2 diabetes have elevated LH levels (Dhindsa et al. 2004, 2011). This is consistent with recent findings that the inhibition of the gonadal axis predominantly takes place in the hypothalamus, especially with more severe obesity
  • Metabolic factors, such as leptin, insulin (via deficiency or resistance) and ghrelin are believed to act at the ventromedial and arcuate nuclei of the hypothalamus to inhibit gonadotropin-releasing hormone (GNRH) secretion
  • ...32 more annotations...
  • kisspeptin has emerged as one of the most potent secretagogues of GNRH release
  • Consistent with the hypothesis that obesity-mediated inhibition of kisspeptin signalling contributes to the suppression of the HPT axis, infusion of a bioactive kisspeptin fragment has been recently shown to robustly increase LH pulsatility, LH levels and circulating testosterone in hypotestosteronaemic men with type 2 diabetes
  • Figure 4
  • Interestingly, a recent 16-week study of experimentally induced hypogonadism in healthy men with graded testosterone add-back either with or without concomitant aromatase inhibitor treatment has in fact suggested that low oestradiol (but not low testosterone) may be responsible for the hypogonadism-associated increase in total body and intra-abdominal fat mass
    • Nathan Goodyear
      Nathan Goodyear on 04 Feb 14
       
      This does not fit with the research on receptors, specifically estrogen receptors.  These studies that the authors are referencing are looking at "circulating" levels, not tissue levels.
  • A smaller study with a similar experimental design found that acute testosterone withdrawal reduced insulin sensitivity independent of body weight, whereas oestradiol withdrawal had no effects
  • Obesity and dysglycaemia and associated comorbidities such as obstructive sleep apnoea (Hoyos et al. 2012b) are important contributors to the suppression of the HPT axis
  • This is supported by observational studies showing that weight gain and development of diabetes accelerate the age-related decline in testosterone
  • Weight loss can reactivate the hypothalamic–pituitary–testicular axis
  • The hypothalamic–pituitary–testicular axis remains responsive to treatment with aromatase inhibitors or selective oestrogen receptor modulators in obese men
  • Kisspeptin treatment increases LH secretion, pulse frequency and circulating testosterone levels in hypotestosteronaemic men with type 2 diabetes
  • Several observational and randomised studies reviewed in Grossmann (2011) have shown that weight loss, whether by diet or surgery, leads to substantial increases in testosterone, especially in morbidly obese men
  • This suggests that weight loss can lead to genuine reactivation of the gonadal axis by reversal of obesity-associated hypothalamic suppression
  • There is pre-clinical and observational evidence that chronic hyperglycaemia can inhibit the HPT axis
  • in those men in whom glycaemic control worsened, testosterone decreased
  • successful weight loss combined with optimisation of glycaemic control may be sufficient to normalise circulating testosterone levels in the majority of such men
  • weight loss, optimisation of diabetic control and assiduous care of comorbidities should remain the first-line approach.
    • Nathan Goodyear
      Nathan Goodyear on 04 Feb 14
       
      This obviously goes against marketing-based medicine
  • In part, the discrepant results may be due to the fact men in the Vigen cohort (Vigen et al. 2013) had a higher burden of comorbidities. Given that one (Basaria et al. 2010), but not all (Srinivas-Shankar et al. 2010), RCTs in men with a similarly high burden of comorbidities reported an increase in cardiovascular events in men randomised to testosterone treatment (see section on Testosterone therapy: potential risks below) (Basaria et al. 2010), testosterone should be used with caution in frail men with multiple comorbidities
  • The retrospective, non-randomised and non-blinded design of these studies (Shores et al. 2012, Muraleedharan et al. 2013, Vigen et al. 2013) leaves open the possibility for residual confounding and multiple other sources of bias. These have been elegantly summarised by Wu (2012).
  • Effects of testosterone therapy on body composition were metabolically favourable with modest decreases in fat mass and increases in lean body mass
  • This suggests that testosterone has limited effects on glucose metabolism in relatively healthy men with only mildly reduced testosterone.
  • it is conceivable that testosterone treatment may have more significant effects on glucose metabolism in uncontrolled diabetes, akin to what has generally been shown for conventional anti-diabetic medications.
  • the evidence from controlled studies show that testosterone therapy consistently reduces fat mass and increases lean body mass, but inconsistently decreases insulin resistance.
  • Interestingly, testosterone therapy does not consistently improve glucose metabolism despite a reduction in fat mass and an increase in lean mass
  • the majority of RCTs (recently reviewed in Ng Tang Fui et al. (2013a)) showed that testosterone therapy does not reduce visceral fat
    • Nathan Goodyear
      Nathan Goodyear on 04 Feb 14
       
      visceral and abdominal adiposity are biologically different and thus the risks associated with the two are different.
    • Nathan Goodyear
      Nathan Goodyear on 04 Feb 14
       
      yet low T is associated with an increase in visceral adiposity--confusing!
  • testosterone therapy decreases SHBG
  • testosterone is inversely associated with total cholesterol, LDL cholesterol and triglyceride (Tg) levels, but positively associated with HDL cholesterol levels, even if adjusted for confounders
  • Although observational studies show a consistent association of low testosterone with adverse lipid profiles, whether testosterone therapy exerts beneficial effects on lipid profiles is less clear
  • Whereas testosterone-induced decreases in total cholesterol, LDL cholesterol and Lpa are expected to reduce cardiovascular risk, testosterone also decreases the levels of the cardio-protective HDL cholesterol. Therefore, the net effect of testosterone therapy on cardiovascular risk remains uncertain.
  • data have not shown evidence that testosterone causes prostate cancer, or that it makes subclinical prostate cancer grow
  • compared with otherwise healthy young men with organic androgen deficiency, there may be increased risks in older, obese men because of comorbidities and of decreased testosterone clearance
  • recent evidence that fat accumulation may be oestradiol-, rather than testosterone-dependent
Nathan Goodyear

Testosterone deficiency syndrome and cardiovascular health: An assessment of beliefs, k... - 0 views

www.ncbi.nlm.nih.gov/...PMC3929476

low T Testosterone cardiovascular disease physicians men male hormone hormones

shared by Nathan Goodyear on 03 Mar 14 - No Cached
  • The vast majority (88%) did not screen cardiac patients for TDS.
  • Testosterone deficiency has a prevalence of 7% in the general population, rising to 20% in elderly males
  • Males with CAD have lower testosterone levels than those with normal coronary angiograms of the same age,5 suggesting that the prevalence of testosterone deficiency is much higher in the CAD population
  • ...14 more annotations...
  • Men with hypertension, another established risk factor for CAD, have lower testosterone compared to normotensive men
  • Recent meta-analyses showed that testosterone levels are generally lower among patients with metabolic syndrome, regardless of the various definitions of metabolic syndrome that are used
  • Testosterone (total and bioavailable) and sex-hormone binding globulin (SHBG) are inversely associated with the prevalence of metabolic syndrome in men between the ages of 40 and 80, and this association persists across racial and ethnic backgrounds
  • ower levels of testosterone and SHBG predict a higher incidence of metabolic syndrome.
  • Low testosterone levels have been related to increased insulin resistance and cardiovascular mortality,12 even in the absence of overt type 2 diabetes mellitus.
  • testosterone levels (total and bioavailable) in middle-aged men are inversely correlated with insulin resistance
  • The Massachusetts Male Aging Study (MMAS) demonstrated that low levels of testosterone and SHBG are independent risk factors for the development of type 2 diabetes,
  • Andropausal men (age 58 ± 7 years) have a higher maximal carotid artery intima-media thickness
  • There is an inverse linear correlation between body mass index (BMI) and wait-to-hip ratio with testosterone and insulin-like growth factor-1 levels.
  • Testosterone supplementation for 1 year in hypogonadal men has been shown to cause a significant improvement in body weight, BMI, waist size, lipid profile, and C-reactive protein levels
  • TRT for 3 months in hypogonadal men with type 2 diabetes significantly improved fasting insulin sensitivity, fasting blood glucose and glycated hemoglobin.
  • Testosterone replacement can improve angina symptoms and delay the onset of cardiac ischemia, likely through a coronary vasodilator mechanism
  • ADT is associated with an increased risk of cardiovascular events, including myocardial infarction and cardiovascular mortality.
  • ADT significantly increases fat mass, decreases lean body mass,29,30 increases fasting plasma insulin and decreases insulin sensitivity31 and increases serum cholesterol and triglyceride levels
  • Nathan Goodyear on 03 Mar 14
     
    Startling study on the knowledge of Testosterone and cardiovascular disease in general practitioners and cardiologists in Canada.  Eight-eight percent did not screen patients with cardiovascular disease for low Testosterone.  A whopping 67% of physicians did not know that low T was a risk factor for cardiovascular disease, yet 62% believed Testosterone would increase exercise tolerance. The lack of knowledge displayed by physicians today is staggering and is an indictment of the governing bodies.  This was a survey conducted in Canada so there are obvious limitations to the strength/conclusion of this study.
Nathan Goodyear

Changes in fat and lean body mass during androgen-de... [Urology. 2004] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...15072892

androgen deprivation therapy men male body composition hormone hormones Testosterone low T fat mass lean muscle prostate cancer

shared by Nathan Goodyear on 03 Mar 14 - No Cached
  • Nathan Goodyear on 03 Mar 14
     
    Androgen deprivation therapy resulted in an 11% increase in fat mass and just under 4% decrease in lean muscle mass in men.  
Nathan Goodyear

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

www.nejm.org/...NEJMoa1206168

Testosterone Estradiol goserelin men male hormone hormones

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

Testosterone and the Cardiovascular System: A Comprehensive Review of the Clinical Lite... - 0 views

jaha.ahajournals.org/...e000272.full

Testosterone men male cardiovascular disease low T

shared by Nathan Goodyear on 20 Nov 13 - No Cached
  • Low endogenous bioavailable testosterone levels have been shown to be associated with higher rates of all‐cause and cardiovascular‐related mortality.39,41,46–47 Patients suffering from CAD,13–18 CHF,137 T2DM,25–26 and obesity27–28
  • have all been shown to have lower levels of endogenous testosterone compared with those in healthy controls. In addition, the severity of CAD15,17,29–30 and CHF137 correlates with the degree of testosterone deficiency
  • In patients with CHF, testosterone replacement therapy has been shown to significantly improve exercise tolerance while having no effect on LVEF
  • ...66 more annotations...
  • testosterone therapy causes a shift in the skeletal muscle of CHF patients toward a higher concentration of type I muscle fibers
  • Testosterone replacement therapy has also been shown to improve the homeostatic model of insulin resistance and hemoglobin A1c in diabetics26,68–69 and to lower the BMI in obese patients.
  • Lower levels of endogenous testosterone have been associated with longer duration of the QTc interval
  • testosterone replacement has been shown to shorten the QTc interval
  • negative correlation has been demonstrated between endogenous testosterone levels and IMT of the carotid arteries, abdominal aorta, and thoracic aorta
  • These findings suggest that men with lower levels of endogenous testosterone may be at a higher risk of developing atherosclerosis.
  • Current guidelines from the Endocrine Society make no recommendations on whether patients with heart disease should be screened for hypogonadism and do not recommend supplementing patients with heart disease to improve survival.
  • The Massachusetts Male Aging Study also projects ≈481 000 new cases of hypogonadism annually in US men within the same age group
  • since 1993 prescriptions for testosterone, regardless of the formulation, have increased nearly 500%
  • Testosterone levels are lower in patients with chronic illnesses such as end‐stage renal disease, human immunodeficiency virus, chronic obstructive pulmonary disease, type 2 diabetes mellitus (T2DM), obesity, and several genetic conditions such as Klinefelter syndrome
  • A growing body of evidence suggests that men with lower levels of endogenous testosterone are more prone to develop CAD during their lifetimes
  • There are 2 major potential confounding factors that the older studies generally failed to account for. These factors are the subfraction of testosterone used to perform the analysis and the method used to account for subclinical CAD.
  • The biologically inactive form of testosterone is tightly bound to SHBG and is therefore unable to bind to androgen receptors
  • The biologically inactive fraction of testosterone comprises nearly 68% of the total testosterone in human serum
  • The biologically active subfraction of testosterone, also referred to as bioavailable testosterone, is either loosely bound to albumin or circulates freely in the blood, the latter referred to as free testosterone
  • It is estimated that ≈30% of total serum testosterone is bound to albumin, whereas the remaining 1% to 3% circulates as free testosterone
  • it can be argued that using the biologically active form of testosterone to evaluate the association with CAD will produce the most reliable results
  • English et al14 found statistically significant lower levels of bioavailable testosterone, free testosterone, and free androgen index in patients with catheterization‐proven CAD compared with controls with normal coronary arteries
  • patients with catheterization‐proven CAD had statistically significant lower levels of bioavailable testosterone
  • In conclusion, existing evidence suggests that men with CAD have lower levels of endogenous testosterone,13–18 and more specifically lower levels of bioavailable testosterone
  • low testosterone levels are associated with risk factors for CAD such as T2DM25–26 and obesity
  • In a meta‐analysis of these 7 population‐based studies, Araujo et al41 showed a trend toward increased cardiovascular mortality associated with lower levels of total testosterone, but statistical significance was not achieved (RR, 1.25
  • the authors showed that a decrease of 2.1 standard deviations in levels of total testosterone was associated with a 25% increase in the risk of cardiovascular mortality
  • the relative risk of all‐cause mortality in men with lower levels of total testosterone was calculated to be 1.35
  • higher risk of cardiovascular mortality is associated with lower levels of bioavailable testosterone
  • Existing evidence seems to suggest that lower levels of endogenous testosterone are associated with higher rates of all‐cause mortality and cardiovascular mortality
  • studies have shown that lower levels of endogenous bioavailable testosterone are associated with higher rates of all‐cause and cardiovascular mortality
  • It may be possible that using bioavailable testosterone to perform mortality analysis will yield more accurate results because it prevents the biologically inactive subfraction of testosterone from playing a potential confounding role in the analysis
  • The earliest published material on this matter dates to the late 1930s
  • the concept that testosterone replacement therapy improves angina has yet to be proven wrong
  • In more recent studies, 3 randomized, placebo‐controlled trials demonstrated that administration of testosterone improves myocardial ischemia in men with CAD
  • The improvement in myocardial ischemia was shown to occur in response to both acute and chronic testosterone therapy and seemed to be independent of whether an intravenous or transdermal formulation of testosterone was used.
  • testosterone had no effect on endothelial nitric oxide activity
  • There is growing evidence from in vivo animal models and in vitro models that testosterone induces coronary vasodilation by modulating the activity of ion channels, such as potassium and calcium channels, on the surface of vascular smooth muscle cells
  • Experimental studies suggest that the most likely mechanism of action for testosterone on vascular smooth muscle cells is via modulation of action of non‐ATP‐sensitive potassium ion channels, calcium‐activated potassium ion channels, voltage‐sensitive potassium ion channels, and finally L‐type calcium ion channels
  • Corona et al confirmed those results by demonstrating that not only total testosterone levels are lower among diabetics, but also the levels of free testosterone and SHBG are lower in diabetic patients
  • Laaksonen et al65 followed 702 Finnish men for 11 years and demonstrated that men in the lowest quartile of total testosterone, free testosterone, and SHBG were more likely to develop T2DM and metabolic syndrome.
  • Vikan et al followed 1454 Swedish men for 11 years and discovered that men in the highest quartile of total testosterone were significantly less likely to develop T2DM
  • authors demonstrated a statistically significant increase in the incidence of T2DM in subjects receiving gonadotropin‐releasing hormone antagonist therapy. In addition, a significant increase in the rate of myocardial infarction, stroke, sudden cardiac death, and development of cardiovascular disease was noted in patients receiving antiandrogen therapy.67
  • Several authors have demonstrated that the administration of testosterone in diabetic men improves the homeostatic model of insulin resistance, hemoglobin A1c, and fasting plasma glucose
  • Existing evidence strongly suggests that the levels of total and free testosterone are lower among diabetic patients compared with those in nondiabetics
  • insulin seems to be acting as a stimulant for the hypothalamus to secret gonadotropin‐releasing hormone, which consequently results in increased testosterone production. It can be argued that decreased stimulation of the hypothalamus in diabetics secondary to insulin deficiency could result in hypogonadotropic hypogonadism
  • BMI has been shown to be inversely associated with testosterone levels
  • This interaction may be a result of the promotion of lipolysis in abdominal adipose tissue by testosterone, which may in turn cause reduced abdominal adiposity. On the other hand, given that adipose tissue has a higher concentration of the enzyme aromatase, it could be that increased adipose tissue results in more testosterone being converted to estrogen, thereby causing hypogonadism. Third, increased abdominal obesity may cause reduced testosterone secretion by negatively affecting the hypothalamus‐pituitary‐testicular axis. Finally, testosterone may be the key factor in activating the enzyme 11‐hydroxysteroid dehydrogenase in adipose tissue, which transforms glucocorticoids into their inactive form.
  • increasing age may alter the association between testosterone and CRP. Another possible explanation for the association between testosterone level and CRP is central obesity and waist circumference
  • Bai et al have provided convincing evidence that testosterone might be able to shorten the QTc interval by augmenting the activity of slowly activating delayed rectifier potassium channels while simultaneously slowing the activity of L‐type calcium channels
  • consistent evidence that supplemental testosterone shortens the QTc interval.
  • Intima‐media thickness (IMT) of the carotid artery is considered a marker for preclinical atherosclerosis
  • Studies have shown that levels of endogenous testosterone are inversely associated with IMT of the carotid artery,126–128,32,129–130 as well as both the thoracic134 and the abdominal aorta
  • 1 study has demonstrated that lower levels of free testosterone are associated with accelerated progression of carotid artery IMT
  • another study has reported that decreased levels of total and bioavailable testosterone are associated with progression of atherosclerosis in the abdominal aorta
  • These findings suggest that normal physiologic testosterone levels may help to protect men from the development of atherosclerosis
  • Czesla et al successfully demonstrated that the muscle specimens that were exposed to metenolone had a significant shift in their composition toward type I muscle fibers
  • Type I muscle fibers, also known as slow‐twitch or oxidative fibers, are associated with enhanced strength and physical capability
  • It has been shown that those with advanced CHF have a higher percentage of type II muscle fibers, based on muscle biopsy
  • Studies have shown that men with CHF suffer from reduced levels of total and free testosterone.137 It has also been shown that reduced testosterone levels in men with CHF portends a poor prognosis and is associated with increased CHF mortality.138 Reduced testosterone has also been shown to correlate negatively with exercise capacity in CHF patients.
  • Testosterone replacement therapy has been shown to significantly improve exercise capacity, without affecting LVEF
  • the results of the 3 meta‐analyses seem to indicate that testosterone replacement therapy does not cause an increase in the rate of adverse cardiovascular events
  • Data from 3 meta‐analyses seem to contradict the commonly held belief that testosterone administration may increase the risk of developing prostate cancer
  • One meta‐analysis reported an increase in all prostate‐related adverse events with testosterone administration.146 However, when each prostate‐related event, including prostate cancer and a rise in PSA, was analyzed separately, no differences were observed between the testosterone group and the placebo group
  • the existing data from the 3 meta‐analyses seem to indicate that testosterone replacement therapy does not increase the risk of adverse cardiovascular events
  • the authors correctly point out the weaknesses of their study which include retrospective study design and lack of randomization, small sample size at extremes of follow‐up, lack of outcome validation by chart review and poor generalizability of the results given that only male veterans with CAD were included in this study
    • Nathan Goodyear
      Nathan Goodyear on 04 Dec 13
       
      The authors here present Total Testosterone as a "confounding" value
    • Nathan Goodyear
      Nathan Goodyear on 09 Dec 13
       
      This would be HSD-II
  • the studies that failed to find an association between testosterone and CRP used an older population group
  • low testosterone may influence the severity of CAD by adversely affecting the mediators of the inflammatory response such as high‐sensitivity C‐reactive protein, interleukin‐6, and tumor necrosis factor–α
  • Nathan Goodyear on 20 Nov 13
     
    Good review of Testosterone and CHD.  Low T is associated with increased all cause mortality and cardiovascular mortality, CAD, CHF, type II diabetes, obesity, increased IMT,  increased severity of CAD and CHF.  Testosterone replacement in men with low T has been shown to improve exercise tolerance in CHF, improve insulin resistance, improve HgbA1c and lower BMI in the obese.
Nathan Goodyear

Subclinical Hypothyroidism, Weight Change, and Body Composition in the Elderly: The Car... - 0 views

press.endocrine.org/...jc.2013-3591

subclinical hypothyroidism weight elderly cardiovascular health

shared by Nathan Goodyear on 16 Apr 14 - No Cached
  • Nathan Goodyear on 16 Apr 14
     
    Study found no significant effect of subclinical hypothyroidism on weight in the elderly.  However, higher free T4 levels were associated with lower baseline weight and weight loss in women. TSH and free T3 were not. associated.
Nathan Goodyear

Circulating Levels of Inflammatory Markers and Cancer Risk in the Health Aging and Body... - 0 views

cebp.aacrjournals.org/...2413.long

inflammatory cytokines inflammation TNF-alpha CRP IL-6 cancer

shared by Nathan Goodyear on 22 Sep 14 - No Cached
  • Nathan Goodyear on 22 Sep 14
     
    Three inflammatory biomarkers, TNF-alpha, CRP and IL-6 found to be associated with cancer.
wheelchairindia9

Karma 8020 Wheelchair - 0 views

www.wheelchairindia.com/...a-8020-X-Heavy-Duty-Wheelchair

Extra Wide Heavy Duty Wheelchair reinforced cross braces Wheelchair Heavy Duty strong structure design larger turning radius Karma 8020 Wheelchair

shared by wheelchairindia9 on 18 Apr 15 - No Cached
  • wheelchairindia9 on 18 Apr 15
     
    This wheelchair of choice for those who desire an extra wide, heavy-duty chair. Bariatric equipment is designed to be used in the care of large and heavy individuals. With childhood obesity levels also rising, the needs of heavier patients and those caring for them, have to be addressed. Wheelchairs that have been constructed for use by the heaviest individuals have built-in strengthening and bracing of the frame, to reduce the possibility of it twisting or buckling in use. The bariatric chairs are available in 20 and 22 inch widths with a red or blue frame. It comes with dual, reinforced steel cross braces for heavy duty support. The seat upholstery is reinforced for long life and comes with a back carry pouch for small items.The 12″ rear wheels are flat free, and the desk length arms are removable and reversible. Features bariatric chairs: Dual, reinforced steel cross braces. Supports individuals. Reinforced steel frame provides added support. Heavy duty, nylon reinforced upholstery with a back carry pouch. Removable, reversible desk length arms. Adjustable leg support. 12″ flat free rear wheels. Using a Karma KM-8020: wheelchairs require more strength to push by the caregiver and by the user, if the chair is self-propelled. In some cases, it may be wise for the caregiver to ask for assistance from another person in order to push the wheelchair safely. Because heavy duty wheelchairs are wider than standard wheelchairs, they require wider doorways and a larger turning radius. They are also heavier to lift into a vehicle and harder to push uphill. Features Can be used as standard self propelled wheelchair or a transport chair all in one. Quick release 24″ wheels can be removed to transition self propelled chair to a transport chair. All aluminum frame. Comes with two sets of aluminum wheel locks: one for use with wheelchair, one for use with transport chair. Fold down back with deluxe back release. Comes standard with swingaway footre
Nathan Goodyear

Testosterone: More Than Having the Guts to Win the Tour de France - 0 views

www.sciencedirect.com/...S1074761313003439

Testosterone gut flora gut microbiome gut microbiota autoimmune disease diabetes

shared by Nathan Goodyear on 30 Apr 15 - No Cached
  • female adult mice have microbiomes similar to those of prepubescent mice of both sexes;
  • the commensal microbial community in adult male mice significantly deviates from this shared initial pool.
  • the microbiome in castrated adult males clearly shifts away from that of normal adult males and is closer to the microbiome of females
  • ...10 more annotations...
  • The incidence of T1D in these mice is positively correlated with the “femaleness” of the microbiota
  • These results support the hypothesis that the host androgen level is influential in determining the composition of the microbiota, which in turn affects T1D initiation and progression
  • a high testosterone level enriches the microbiota for specific organisms such as segmented filamentous bacteria (SFB) and Escherichia coli or Shigella–like (SECS) strains.
  • A minimum level of testosterone and specific male-enriched microbes working together upregulate M2 macrophage and IFN-γ producing T cells in pancreatic lymph nodes. Microarray data show that both the IFN-γ and IL-1β pathways are also stimulated.
  • These microbes also upregulate host testosterone
  • In four independent experiments, the authors found no universal unique “male microbiome”
  • they did find that four distinct combinations of microbial groupings (with an interesting lack of overlap at the individual family level in the four experiments) were enhanced by androgen
  • one species consists of the segmented filamentous bacteria (SFB) and belongs to the Firmicutes, whereas the other is an Escherichia coli or Shigella–like (SECS) strain belonging to the Proteobacteria
  • colonization with protective microbiomes—e.g., SPF microbiota, SFB, and SECS—is positively correlated with high blood testosterone levels in male mice
  • A direct implication of this study is that probiotic administration or fecal transplantation is a theoretically possible approach to protection against T1D
  • Nathan Goodyear on 30 Apr 15
     
    nice summary of article on the relationship between Testosteorne and gut microbiome in autoimmune disease.
Nathan Goodyear

Effect of the long-term feeding of dietary lipids on the learning ability, fatty acid c... - 0 views

www.sciencedirect.com/...S0047637497001693

DHA learning fish oil n-3 omega 3 omega-3 memory

shared by Nathan Goodyear on 01 Nov 13 - No Cached
  • Nathan Goodyear on 01 Nov 13
     
    mouse study finds high DHA diet improved learning.
wheelchairindia9

Best Wheelchair For Heavy Person - 0 views

disabilityproduct.in/...HEAVY-DUTY-WHEELCHAIR

Take Safer Shower with a Shower Commode Stool or Chair safely and comfortably provide comfortable and ergonomic support convenient and secure facility easy to keep clean removable or swing away armrests

shared by wheelchairindia9 on 05 Aug 15 - No Cached
  • wheelchairindia9 on 05 Aug 15
     
    People who are very large or heavy may have difficulty using regular chairs. In some cases, they are simply too wide to comfortably fit in an average-sized chair, and in other cases their weight may damage or break the chair entirely. This is not only humiliating to the person who sits in the chair, but could result in injury if the chair collapses. To avoid such an unfortunate occurrence as well as potential litigation, it is important to purchase heavy duty chairs that can accommodate larger family members, employees, and customers. Heavy duty wheelchairs can also be made for specific purposes. An off-road wheelchair, for example, is a heavy duty wheelchair designed for individuals who intend on spending a lot of time on rugged terrain. The most common type of heavy duty wheelchair is a bariatric wheelchair, which is designed to allow larger individuals adequate mobility. For this matter, heavy duty wheelchairs typically have larger seats than conventional wheelchairs. The frames of these wheelchairs can be made from several different reinforced metals, although a titanium wheelchair is often the most popular choice. The wheels themselves are made of thicker rubber than normal, preventing any possible failure due to the greater amount of weight supported. Most makes of heavy duty wheelchairs fold like regular wheelchairs, making storage relatively easy despite the wheelchair's increased size. For the user's convenience, a heavy duty wheelchair can either be manually-operated or motorized, each with its own pros and cons. A manual Heavy Duty Wheelchair gives full control of motion to the user, but the added weight from the reinforcements makes pushing or propelling the wheelchair much harder than normal. A motorized heavy duty wheelchair offers a solution to this dilemma, but is often more expensive and harder to maintain than a manual wheelchair. Some designs offer a combination of both, with a small motor assisting those pushing the wheelchair. The proper c
Nathan Goodyear

Changes in Weight, Body Composition, and Factors Influencing Energy Balance Among Preme... - 0 views

jco.ascopubs.org/...2381.short

chemotherapy breast cancer muscle weight gain obesity cancer

shared by Nathan Goodyear on 26 Aug 15 - No Cached
  • Nathan Goodyear on 26 Aug 15
     
    study finds weight gain in premenopausal breast cancer survivors on adjuvant chemo is due to sarcopenia.
wheelchairindia9

Recliner Wheelchair - 0 views

www.wheelchairindia.com/...RECLINING-WHEELCHAIR

Prepare Complete Flexibility With Reclining Wheelchair positioned for maximum comfort available in foldable frames reclining under desks legs and feet can also be re-positioned extended head supports and seat using high quality material

shared by wheelchairindia9 on 20 May 15 - No Cached
  • wheelchairindia9 on 20 May 15
     
    Reclining wheelchairs, since the product class is built around one key feature: the capability to adjust the backrest and/or footrest into a reclined position. This feature is especially important to users who find it difficult or impossible to sit in a fully upright position, and users who sleep in their chairs frequently. For those that are looking for a more portable chair. When compared with a similar, non-reclining chair, a reclining wheelchair tends to weigh more and - unlike other manual models - manual wheelchairs that recline typically aren't foldable. reclining wheelchair compensates mechanically for body positioning by automatically readjusting armrests and lateral supports.

    Recliner wheelchair is low profile allowing to comfortably fit under tables and desks. Enjoy numerous activities with increased comfort such as stretching, napping and watching television. The ability to recline also improves circulation and the ability for sore spots to heal.

    Karma Reclining Wheelchair KM 5000:
    The karma reclining wheelchair km-5000 Transport Wheelchair is an ultra lightweight folding aluminum reclining wheelchair. With full length padded armrests, an adjustable height head pillow, and more this wheelchair has added comfort for any user. This chair also features swing-away elevating footrests and adjustable length leg supports and footplates. With a weight of 33 Lbs this chair can be transported with ease.

    Karma Reclining Wheelchair KM 5000 Features:
    Folding 6061 T-6 Aircraft-grade aluminum frame in black
    powder coat finish
    Backrest Reclines 90°~163° and includes anti-tippers
    Full length padded detachable armrests with side panels
    Swing-away detachable elevating footrests
    Adjustable length leg supports & footplates
    Adjustable-height head pillow
    14" Mag wheels with flat free polyurethane tires
    7" x 1" Flat free front polyurethane casters
    Adjustab
wheelchairindia9

Commode Wheelchair - 0 views

disabilityproduct.in/...COMMODE-WHEELCHAIR

Bariatric Designed For Maximum Strength Extra Wide Wheelchair wheelchair bariatric Adjusting to the hemi height fold-able wheelchairs commode wheelchair

shared by wheelchairindia9 on 10 Aug 15 - No Cached
  • wheelchairindia9 on 10 Aug 15
     
    This lightweight portable shower chair commode with casters is packed with features to ensure a pleasant and comfortable bathing experience. One of the greatest benefits is the ultra comfort padded seat featuring an open front design making personal hygiene easy and convenient. When the shower chair is not in use the back and 12 qt. commode bucket can be removed without tools making cleaning and storage simple. The frame is manufactured with lightweight rust resistant anodized aluminum able to withstand a 300 lb. weight capacity. Easy to operate, shower chair. Commode comes equipped with 3" non-skid casters, making transfer to and from any bathroom safe and secure. Commode/shower chair soft seat features strong and practical armrests designed to withstand a lot of load, including the sideways forces that are exerted during sideways transfers.The armrests offer comfortable support for the forearms while sitting and they are long enough to provide sustained support when standing up and sitting down. The armrests can be folded up individually, e.g. to facilitate a sideways transfers. When folded down, the armrest rests behind the backrest thereby preventing fingers, skin or hair from getting caught. Commode Wheelchair Rainbow 6: Karma commode wheelchair rainbow 6 comes with lot of exiting features for elderly or physically challenged person who want commode in wheelchair. Karma Rainbow 6 has single seat with center cut commode having cushion cover on top and removable pan or plastic commode seat with pot. Commode Wheelchair Rainbow 6 Features: Frame Material : M.S.Chrome Plated Single Seat with center cut commode Both Option Available In Single Seat Plastic Commode Seat With Pot. Cushioned Top Cover Square Pan Commode Pan Removable Pan Commode Wheelchair Rainbow 6 Measurements: Frame Style : Foldable Open Position Wheel To Wheel Width In : 26" (Inches) Seat Width : 18" (Inches) Total Width in Closing Position : 11" (Inches) Rear Whe
Nathan Goodyear

Cambridge Journals Online - Abstract - Effects of whey protein isolate on body composit... - 0 views

journals.cambridge.org/...displayAbstract

Whey protein elevated cholesterol insulin resistance diabetes

shared by Nathan Goodyear on 20 Jan 11 - No Cached
  • The present study demonstrated that supplementation with whey proteins improves fasting lipids and insulin levels in overweight and obese individuals.
  • Nathan Goodyear on 20 Jan 11
     
    Whey protein improves fasting lipids and insulin levels
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