Skip to main content

Home/ Dr. Goodyear/ Group items matching "Fat" in title, tags, annotations or url

Group items matching
in title, tags, annotations or url

Sort By: Relevance | Date Filter: All | Bookmarks | Topics Simple Middle
Nathan Goodyear

LeptiPro - Intelligent Weight Control - 0 views

www.leptinresearch.org

Leptin resistance obese overweight weight loss

shared by Nathan Goodyear on 08 Mar 11 - No Cached
  • "leptin resistance."
  • In order for leptin to control body weight and metabolism, it must do so from the hypothalamic centers in the brain,
  • When brain levels of leptin are low due to "leptin resistance" - even if there are high circulating blood levels of leptin - food cravings and weight gain occur because the body believes that it is hungry and goes into a state of continued fat storage.
  • ...2 more annotations...
  • By reversing "leptin resistance," through the blocking of PTP1 B, the function of the protein hormone leptin is restored so that the hypothalamic center can normally and effectively modulate body weight and metabolism.
  • Published studies demonstrate that the botanically derived phytochemical, isolated and purified single-peak Isoquinoline Alkaloid Berberine Hel, specifically and potently inhibits human Protein Tyrosine Phosphates 1B (PTP1 B).
  • Nathan Goodyear on 08 Mar 11
     
    Obese or struggling with weight?  look to Leptin
Nathan Goodyear

The major green tea polyphenol, (-)-epigallocatech... [J Nutr. 2008] - PubMed result - 0 views

www.ncbi.nlm.nih.gov/...18716169

green tea extract weight loss

shared by Nathan Goodyear on 05 May 11 - No Cached
  • Our results indicate that long-term EGCG treatment attenuated the development of obesity, symptoms associated with the metabolic syndrome, and fatty liver. Short-term EGCG treatment appeared to reverse preexisting high-fat-induced metabolic pathologies in obese mice. These effects may be mediated by decreased lipid absorption, decreased inflammation, and other mechanisms.
  • Nathan Goodyear on 05 May 11
     
    Green tea extract results in weight loss, both short-term and long-term
Nathan Goodyear

Green tea (-)-epigallocatechin-3-gallate reduces b... [Ann Nutr Metab. 2009] - PubMed result - 0 views

www.ncbi.nlm.nih.gov/...19390166

green tea extract obesity weight loss

shared by Nathan Goodyear on 05 May 11 - No Cached
  • green tea EGCG effectively reduces adipose tissue mass and ameliorates plasma lipid profiles in high-fat diet-induced obese mice.
  • Nathan Goodyear on 05 May 11
     
    Green tea extract and weight loss in obesity
Nathan Goodyear

The implication of obesity and central fat on markers of chronic inflammation: The ATTICA study - 0 views

www.atherosclerosis-journal.com/...abstract

obesity inflammation CRP fibrinogen IL-6

shared by Nathan Goodyear on 14 Aug 11 - No Cached
  • Nathan Goodyear on 14 Aug 11
     
    obesity increases inflammation
Nathan Goodyear

International Journal of Obesity - Antiobesity action of peripheral exenatide (exendin-4) in rodents: effects on food intake, body weight, metabolic status and side-effect measures - 0 views

www.nature.com/...0803284a.html

exanatide Byetta obesity fatty liver weight loss

shared by Nathan Goodyear on 06 Apr 11 - No Cached
  • Systemic exenatide reduces body weight gain in normal, high-fat-fed rodents
  • role in metabolic pathways mediating food intake.
  • the first of which to be identified was an enhancement of glucose-dependent insulin secretion
  • ...5 more annotations...
  • limits glucose appearance via glucose-dependent slowing of gastric emptying
  • suppression of inappropriately elevated postprandial glucagon secretion
  • promote pancreatic -cell proliferation and islet cell neogenesis in both animal and in vitro studies
  • short-term regulator of food intake
  • eceptor agonism in satiety
  • Nathan Goodyear on 06 Apr 11
     
    exanatide helps in obesity and fatty liver treatment
Nathan Goodyear

Curcumin Inhibits Adipogenesis in 3T3-L1 Adipocytes and Angiogenesis and Obesity in C57/BL Mice - 0 views

jn.nutrition.org/...919.abstract

curcumin adipogenesis obesity weight loss

shared by Nathan Goodyear on 28 Apr 11 - No Cached
  • Dietary polyphenols may suppress growth of adipose tissue through their antiangiogenic activity and by modulating adipocyte metabolism
  • curcumin, the major polyphenol in turmeric spice
  • curcumin suppression of angiogenesis in adipose tissue together with its effect on lipid metabolism in adipocytes may contribute to lower body fat and body weight gain
  • ...1 more annotation...
  • Our findings suggest that dietary curcumin may have a potential benefit in preventing obesity
  • Nathan Goodyear on 28 Apr 11
     
    Curcumin useful in obesity
Nathan Goodyear

The effects of exercise training on fat-mass loss ... [Sports Med. 2007] - PubMed result - 0 views

www.ncbi.nlm.nih.gov/...17190534

exercise muscle mass

shared by Nathan Goodyear on 11 Jul 11 - No Cached
  • Nathan Goodyear on 11 Jul 11
     
    exercise increases muscle mass
Nathan Goodyear

Obesity - Resistance Training Conserves Fat-free Mass and Resting Energy Expenditure Following Weight Loss - 0 views

www.nature.com/...oby200838a.html

obesity resistance training weight weight loss loss

shared by Nathan Goodyear on 11 Jul 11 - No Cached
  • Nathan Goodyear on 11 Jul 11
     
    resistance focused exercise helps to reduce muscle loss in weight loss programs;  this has very important implications in ability to maintain weight loss
Nathan Goodyear

Liver X Receptors Downregulate 11β-Hydroxysteroid Dehydrogenase Type 1 Expression and Activity - 0 views

diabetes.diabetesjournals.org/...2426.long

11-betaHSD 11-betaHSD1 cortisol hormone hormones liver fat adipose tissue adipose tissue

shared by Nathan Goodyear on 05 Jun 14 - No Cached
  • Nathan Goodyear on 05 Jun 14
     
    11beta-HSD type 1 is predominantly expressed in liver and adipose tissue.
Nathan Goodyear

Immunohistochemical localization of ... [J Clin Endocrinol Metab. 1998] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...9543163

11-betaHSD 11-betaHSD1 cortisol hormone hormones ovary liver fat adipose tissue adrenal glands

shared by Nathan Goodyear on 05 Jun 14 - No Cached
  • Nathan Goodyear on 05 Jun 14
     
    11beta-HSD type I is highly expressed in liver, adrenal glands, ovaries, and adipose tissue in human immunohistochemical analysis.
Nathan Goodyear

European Journal of Clinical Nutrition - Effect of maternal n-3 long-chain polyunsaturated fatty acid supplementation during pregnancy and/or lactation on adiposity in childhood: a systematic review and meta-analysis of randomized controlled trials - 0 views

www.nature.com/...ejcn2014158a.html

nutrition n-3 omega 3 omega-3 fish oil pregnancy childhood obesity

shared by Nathan Goodyear on 22 Dec 14 - No Cached
  • It is estimated that approximately 30% of children and adolescents in the United States and about 15–30% of those in Europe can be classified as overweight or obese
  • An increasing body of evidence now suggests that the nutritional environment encountered in utero and the early postnatal life may elicit permanent alterations in adipose tissue structure or function and, thereby, programme the individual’s propensity to later obesity
  • The composition of fatty acids in the Western diets has shifted toward an increasing dominance of n-6 relative to n-3 LCPUFAs over the past decades.9,10 This shift is also reflected in the fatty acid composition of breast milk
  • ...8 more annotations...
  • Evidence from animal studies suggests that the n-6 LCPUFA arachidonic acid promotes adipose tissue deposition, whereas the n-3 LCPUFAs eicosapentaenoic acid and docosahexaenoic acid seem to exert an opposite effect
  • Overall, no effect of supplementation was found on BMI in preschool (<5 years) and school-aged (6–12 years) children
  • increased adiposity, once established in childhood, tends to track into adulthood
  • Many studies have shown that even children <2 years with a high BMI are at increased risk of developing obesity later in life
  • The acquisition of fat cells early in life appears to be an irreversible process
  • Evidence from cell culture and animal studies suggests that early exposure to n-3 LCPUFAs has the potential to limit adipose tissue deposition mainly by attenuating the production of the arachidonic acid metabolite prostacyclin, which has been shown to enhance adipogenesis
  • In conclusion, there is currently no evidence to support that maternal n-3 LCPUFA supplementation during pregnancy and/or lactation exerts a favourable programming effect on adiposity status in childhood
  • our systematic review highlights that most of the trials reviewed were prone to methodological limitations
  • Nathan Goodyear on 22 Dec 14
     
    Literature review finds limited data (9 studies, only 6 RCTs) of omega-3 during pregnancy.  No data was found that supported reduced obesity in children by mothers taking n-3 during pregnancy.  No harm was found either.  Data was sparse.   Take home: not enough data, no harm to pregnancy, children, thus if indications are present for mother, then recommend n-3.  At this point not studies have pointed to reduced obesity in children.
Nathan Goodyear

Fructose consumption: potential mechanisms for its effects t... : Current Opinion in Lipidology - 0 views

journals.lww.com/...tial_mechanisms_for_its.5.aspx

fructose insulin resistance lipids triglycerides fat adipose tissue adipose

shared by Nathan Goodyear on 27 Aug 14 - No Cached
  • Nathan Goodyear on 27 Aug 14
     
    fructose leads to direct increase in lipid liver load, post prandial hypertriglyceridemia, and hepatic insulin resistance.
Nathan Goodyear

Testosterone replacement therapy improves i... [Eur J Endocrinol. 2006] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...16728551

low T low Testosterone low T men male hormone hormones Testosterone diabetes hypogonadism visceral fat cholesterol replacement therapy

shared by Nathan Goodyear on 07 Aug 14 - No Cached
  • Nathan Goodyear on 07 Aug 14
     
    In obese men with low T and type 2 diabetes, Testosterone replacement improves insulin sensitivity.  Glycated hemoglobin was also improved.  In this study group, a decrease in visceral adiposity and TC was seen.
Nathan Goodyear

Association Between Endogenous Sex Hormones and Liver Fat in a Mult... - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...25592661

Testosterone Estradiol SHBG hormone hormones men women non-alcoholic fatty liver fatty liver CVD cardiovascular disease cardiovascular disease

shared by Nathan Goodyear on 02 Feb 15 - No Cached
  • Nathan Goodyear on 02 Feb 15
     
    Time that physicians start following the science.  Study using data from the Multi-ethnic Study of Atherosclerosis was used to assess hormones and fatty liver in men and women.  Increasing bioavailable Testosterone levels in women was found to be associated with increasing fatty liver in post-menopausal women.  The opposite was found to be true in men.  Higher Estradiol levels were found to be associated with increased fatty liver in both sexes.  However, the statistical significance was higher with men.  Higher SHBG was associated with lower fatty liver incidence in men.  
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

The striking similarities in the metabolic associations of female androgen excess and male androgen deficiency - 0 views

humrep.oxfordjournals.org/...humrep.deu198.short

hormone hormones men women Testosterone androgens female male metabolism fat adipose adiposity

shared by Nathan Goodyear on 13 Aug 14 - No Cached
  • Nathan Goodyear on 13 Aug 14
     
    I love this abstract.  I am going to try and find the full print.  As it relates to metabolic dysfunction, elevated Testosterone provides a similar functional picture in women as low Testosterone does in men.
Nathan Goodyear

http://www.centromedicoathenas.com.br/Content/Uploads/Info/158.pdf - 0 views

www.centromedicoathenas.com.br/...158.pdf

Testosterone men male hormone hormones muscle fat obesity

shared by Nathan Goodyear on 19 Feb 15 - No Cached
  • Nathan Goodyear on 19 Feb 15
     
    to be read.
Nathan Goodyear

Testosterone level in men with type 2 diabetes mellitus and related metabolic effects: A review of current evidence - 0 views

www.ncbi.nlm.nih.gov/...PMC4364844

low T low Testosterone Diabetes Testosterone men male hormones metabolic syndrome

shared by Nathan Goodyear on 30 Mar 15 - No Cached
  • defined by consistent symptoms and signs of androgen deficiency, and an unequivocally low serum testosterone level
  • the threshold serum testosterone level below which adverse clinical outcomes occur in the general population is not known
  • most population-based studies use the serum testosterone level corresponding to the lower limit, quoted from 8.7 to 12.7 nmol/L, of the normal range for young Caucasian men as the threshold
    • Nathan Goodyear
      Nathan Goodyear on 31 Mar 15
       
      this equals 251 to 366 in serum Total Testosterone
  • ...57 more annotations...
  • Researchers tried to examine whether serum total or free testosterone would be a better/more reliable choice when studying the effect of testosterone. The results were mixed. Some reported significant associations of both serum total and free testosterone level with clinical parameters25, whereas others reported that only serum free testosterone26 or only serum total testosterone6 showed significant associations.
  • −0.124 nmol/L/year in serum total testosterone
    • Nathan Goodyear
      Nathan Goodyear on 31 Mar 15
       
      this equates to a 4 ng/dl decline annually in total Testosterone.
  • In experimental studies, androgen receptor knockout mice developed significant insulin resistance rapidly
  • In mouse models, testosterone promoted differentiation of pluripotent stem cells to the myogenic lineage
  • testosterone decreased insulin resistance by enhancing catecholamine induced lipolysis in vitro, and reducing lipoprotein lipase activity and triglyceride uptake in human abdominal tissue in vivo
  • by promoting lipolysis and myogenesis, testosterone might lead to improved insulin resistance
  • testosterone regulated skeletal muscle genes involved in glucose metabolism that led to decreased systemic insulin resistance
  • In the liver, hepatic androgen receptor signaling inhibited development of insulin resistance in mice
  • independent and inverse association of testosterone with hepatic steatosis shown in a cross-sectional study carried out in humans
  • In short, androgen improves insulin resistance by changing body composition and reducing body fat.
  • Although a low serum testosterone level could contribute to the development of obesity and type 2 diabetes through changes in body composition, obesity might also alter the metabolism of testosterone
  • In obese men, the peripheral conversion from testosterone to estrogen could attenuate the amplitude of luteinizing hormone pulses and centrally inhibit testosterone production
  • leptin, an adipokine, has been shown to be inversely correlated with serum testosterone level in men
  • Leydig cells expressed leptin receptors and leptin has been shown to inhibit testosterone secretion, suggesting a role of obesity and leptin in the pathogenesis of low testosterone
    • Nathan Goodyear
      Nathan Goodyear on 31 Mar 15
       
      So what is "unequivocal"?
  • Baltimore Longitudinal Study of Aging (BLSA) cohort made up of 3,565 middle-class, mostly Caucasian men from the USA, the incidence of low serum total testosterone increased from approximately 20% of men aged over 60 years, 30% over 70 years, to 50% over 80 years-of-age
  • 30–44% sex hormone binding globulin (SHBG)-bound testosterone and 54–68% albumin-bound testosterone
  • As the binding of testosterone to albumin is non-specific and therefore not tight, the sum of free and albumin-bound testosterone is named bioavailable testosterone, which reflects the hormone available at the cellular level
  • Serum total testosterone is composed of 0.5–3.0% of free testosterone unbound to plasma proteins
  • alterations in SHBG concentration might affect total serum testosterone level without altering free or bioavailable testosterone
  • listed in Table​T
  • A significant, independent and longitudinal effect of age on testosterone has been observed with an average change of −0.124 nmol/L/year in serum total testosterone28. The same trend has been shown in Europe and Australia
  • Asian men residing in HK and Japan, but not those living in the USA, had 20% higher serum total testosterone than in Caucasians living in the USA, as shown in a large multinational observational prospective cohort of the Osteoporotic Fractures in Men Study
  • subjects with chronic diseases consistently had a 10–15% lower level compared with age-matched healthy subjects
  • In Caucasians, the mean serum total testosterone level for men in large epidemiological studies has been reported to range from 15.1 to 16.6 nmol/L
  • Asians, higher values, ranging from 18.1 to 19.1 nmol/L, were seen in Korea and Japan
  • Chinese middle-aged men reported a similar mean serum testosterone level of 17.1 nmol/L in 179 men who had a family history of type 2 diabetes and 17.8 nmol/L in 128 men who had no family history of type 2 diabetes
  • The reduction of total testosterone was 0.4% per year in both groups
  • HK involving a cohort of 1,489 community-dwelling men with a mean age of 72 years, a mean serum total testosterone of 19.0 nmol/L was reported
  • pro-inflammatory factors, such as tumor necrosis factor-α in the testes, could locally inhibit testosterone biosynthesis in Leydig cells47, and testosterone treatment in men was shown to reduce the level of tumor necrosis factor-α
  • In Asians, a genetic deletion polymorphism of uridine diphosphate-glucuronosyltransferase UGT2B17 was associated with reduced androgen glucuronidation. This resulted in higher level of active androgen in Asians as compared to Caucasians, as Caucasians' androgen would be glucuronidated into inactive forms faster.
  • Compared with Caucasians, the frequency of this deletion polymorphism of UGT2B17 was 22-fold higher in Asian subjects
  • Other researchers have suggested that environmental, but not genetic, factors influenced serum total testosterone
  • The basal and ligand-induced activity of the AR is inversely associated with the length of the CAG repeat chain
  • In the European Male Aging Study, increased estrogen/androgen ratio in association with longer AR CAG repeat was observed
  • a smaller number of AR CAG repeat had been shown to be associated with benign prostate hypertrophy and faster prostate growth during testosterone treatment
  • In India, men with CAG ≤19 had increased risk of prostate cancer
  • the odds of having a short CAG repeat (≤17) were substantially higher in patients with lymph node-positive prostate cancer than in those with lymph node-negative disease or in the general population
  • assessing the polymorphism at the AR level could be a potential tool towards individualized assessment and treatment of hypogonadism.
  • In elderly men, there was reduced testicular response to gonadotropins with suppressed and altered pulsatility of the hypothalamic pulse generator
  • a significant, independent and longitudinal effect of age on serum total testosterone level had been observed
  • A significant graded inverse association between serum testosterone level and insulin levels independent of age has also been reported in Caucasian men
  • Low testosterone is commonly associated with a high prevalence of MES
  • most studies showed that changes in serum testosterone level led to changes in body composition, insulin resistance and the presence of MES, the reverse might also be possible
  • MES predicted a 2.6-fold increased risk of development of low serum testosterone level independent of age, smoking and other potential confounders
  • Other prospective studies have shown that development of MES accelerated the age-related decline in serum testosterone level
  • In men with type 2 diabetes, changes in serum testosterone level over time correlated inversely with changes in insulin resistance
  • weight loss by either diet control or bariatric surgery led to a substantial increase in total testosterone, especially in morbidly obese men, and the rise in serum testosterone level was proportional to the amount of weight lost
  • To date, published clinical trials are small, of short duration and often used pharmacological, not physiological, doses of testosterone
  • In the population-based Osteoporotic Fractures in Men Study cohort from Sweden, men in the highest quartile of serum testosterone level had the lowest risk of cardiovascular events compared with men in the other three quartiles (hazard ratio [HR] 0.70
  • low serum total testosterone was associated with a significant fourfold higher risk of cardiovascular events when comparing men from the lowest testosterone tertile with those in the highest tertile
  • Shores et al. were the first to report that low serum testosterone level, including both serum total and free testosterone, was associated with increased mortality
  • low serum total testosterone predicted increased risk of cardiovascular mortality with a HR of 1.38
  • low serum total testosterone increased all-cause (HR 1.35, 95% CI 1.13–1.62, P < 0.001) and cardiovascular mortality (HR 1.25
  • European Association for the Study of Diabetes 2013 suggested there was an inverse relationship between serum testosterone level and acute myocardial infarction
  • Diabetic men in the highest quartile of serum total testosterone had a significantly reduced risk of acute MI when compared with those in the lower quartiles
  • serum total testosterone level in the middle two quartiles at baseline predicted reduced incidence of death compared with having the highest and lowest levels
  • Nathan Goodyear on 30 Mar 15
     
    Nice review of Testosterone levels and some of the evidence linking Diabetes with low T.  However, the conclusion by the authors regarding what is causing the low T in men with Diabetes is baffling.  The literature does not point to one cause, it is clearly multifactorial--obesity, inflammation, high aromatase activity...I would suggest the authors continue their readings in the manner.
Nathan Goodyear

Berberine Improves Insulin Sensitivity by Inhibiting Fat Store and Adjusting Adipokines Profile in Human Preadipocytes and Metabolic Syndrome Patients - 0 views

www.hindawi.com/...363845

berberine BMI obesity metabolic syndrome leptin leptin resistance insulin resistance adiponectin natural alternative

shared by Nathan Goodyear on 25 Mar 15 - No Cached
  • Nathan Goodyear on 25 Mar 15
     
    Berberine reduced BMI, improved insulin sensitivity, improved leptin sensitivity, and improved leptin:adiponectin ratio levels in people with metabolic syndrome after 3 months.
Nathan Goodyear

Longitudinal Effects of Aging on Serum Total and Free Testosterone Levels in Healthy Men: The Journal of Clinical Endocrinology & Metabolism: Vol 86, No 2 - 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.
« First ‹ Previous 361 - 380 of 395 Next ›
Showing 20▼ items per page