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Nathan Goodyear

Circulating 2-hydroxy and 16-α hydroxy estrone levels and risk of breast canc... - 1 views

www.ncbi.nlm.nih.gov/...PMC2562592

estrogen metabolism menopause post-menopause post menopause estrogen metabolite 2-OH-estrone 16-alpha-OH-estrone 2:16alpha-OH estrone breast cancer risk hormone hormones

shared by Nathan Goodyear on 21 Aug 14 - No Cached
  • 2-OH estrogens bind to the estrogen receptor (ER) with affinity equivalent to or greater than estradiol
  • previous prospective studies have not observed any significant associations with either 2-OH or 16α-OH estrone or the ratio of the two metabolites and breast cancer risk overall.
    • Nathan Goodyear
      Nathan Goodyear on 08 Oct 15
       
      whether that risk is increased or decreased
  • it has been hypothesized that metabolism favoring the 2-OH over the 16α-OH pathway may be inversely associated with breast cancer risk (28).
  • ...24 more annotations...
  • they may act as only weak mitogens (14, 15), or as inhibitors of proliferation
  • No significant associations have been observed between 2-OH estrone and breast cancer risk
  • While 16α-OH estrone binds to the ER with lower affinity than estradiol, it binds covalently (18-20) and once bound, fails to down-regulate the receptor (21). Thus, 16α-OH estrone stimulates cell proliferation in a manner comparable to estradiol in ER+ breast cancer cell lines
  • In this large prospective study of 2-OH and 16α-OH estrone metabolites and breast cancer risk, we did not observe any significant associations overall with either individual metabolite or with the ratio of the two metabolites
  • we observed positive associations with 2-OH estrone and the 2:16α-OH estrone ratio among women with lower BMI and women with ER-/PR-tumors,
  • To date, several epidemiologic studies have examined the association between the 2-OH and 16α-OH estrogen metabolites and breast cancer risk with inconclusive results.
  • circulating estrogen levels have been associated more strongly with ER+/PR+ tumors than with ER-/PR- tumors
  • our results do not support the hypothesis that metabolism favoring the 2-OH estrone pathway is more beneficial to breast cancer risk than that favoring the 16α-OH estrone pathway
  • we observed significant positive associations of both 2-OH estrone and the 2:16α-OH estrone ratio with ER-/PR-tumors
  • Three (30, 32, 33) of four (30-33) studies observed RRs above 1 for the association between 16α-OH estrone and breast cancer risk (range of RRs=1.23-2.47); none of the point estimates was statistically significant though one trend was suggestive
  • based on animal studies, 2-OH estrone and the 2:16α-OH estrone ratio have been hypothesized to be inversely associated with breast cancer risk
  • No significant associations have been observed between 2-OH estrone, 16α-OH estrone, or the 2:16α-OH estrone ratio and breast cancer risk and the direction of the estimates is not consistent across studies.
    • Nathan Goodyear
      Nathan Goodyear on 08 Oct 15
       
      better worded is no consistent, significant associations.   There are some studies that point to the 16 catecholestrogen and increased cancer risk; limited studies show negative effects of 2 catecholestrogens on cancer risk and prospective studies available pretty much dispel the idea that the 2:16 ratio has an risk predictability.
  • we observed a suggestive inverse association with 16α-OH estrone and a significant positive association with the 2:16α-OH estrone ratio among lean women, suggesting possible associations in a low estrogen environment.
  • 16α-OH estrone increases unscheduled DNA synthesis in mouse mammary cells (27) and hence also may be genotoxic
  • Although 2-OH estrogens are capable of redox cycling, the semiquinones and quinones (i.e., the oxidized forms) form stable DNA adducts that are reversible without DNA destruction
  • In our population of PMH nonusers, we observed no associations with ER+/PR+ tumors, but significant positive associations with 2-OH estrone and the 2:16α-OH estrone ratio among women with ER-/PR- tumors
    • Nathan Goodyear
      Nathan Goodyear on 08 Oct 15
       
      one of the few studies to find this association between 2 catecholestrogens and the 2:16 ratio and ER-/PR-tumors
  • Animal and in vitro studies have shown that hydroxy estrogens can induce DNA damage either directly, through the formation of quinones and DNA adducts, or indirectly, through redox cycling and the generation of reactive oxygen species
    • Nathan Goodyear
      Nathan Goodyear on 08 Oct 15
       
      genotoxic via directe DNA adducts and indirectly via ROS; this is in addition to the proliferative effect
  • we observed a significant positive association between the 2:16α-OH estrone ratio and breast cancer risk among lean women
  • No significant associations have been observed with the 2:16α-OH estrone ratio
  • In the Danish study, no associations were observed with either ER+ or ER- tumors among PMH nonusers
  • significant positive associations with 2-OH estrone and the 2:16α-OH estrone ratio were observed among PMH users with ER+, but not ER-, tumors
  • it is possible that the genotoxicity of 2-OH estrone plays a role in hormone receptor negative tumors
  • 4-OH estrogens have a greater estrogenic potential than 2-OH estrogens, given the lower dissociation rate from estrogen receptors compared with estradiol (61), and are potentially more genotoxic since the quinones form unstable adducts, leading to depurination and mutation in vitro and in vivo
  • the balance between the catechol (i.e., 2-OH and 4-OH) and methoxy (i.e., 2-Me and 4-Me) estrogens may impact risk
  • Nathan Goodyear on 21 Aug 14
     
    The risks of estrogen metabolism are not clear cut.  Likely never will be due to the complexity of individual metabolism.  This study found no correlation between 2OH-Estrone and 2OH:16alpha-Estrone and breast cancer risk in ER+/PR+ breast cancer.  Translated: no benefit in breast cancer risk in 2OH-Estrone metabolism or increased 2OH:16alpha estrone metabolism.  There was a positive association between 2OH-Estrone and 2:16alpha-Estrone in women with ER-/PR- tumors and low BMI.
  • anonymous on 28 Oct 15
     
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Nathan Goodyear

Hormone Therapy, Estrogen Metabolism, and Risk of Breast Cancer in the Women's Health I... - 0 views

www.ncbi.nlm.nih.gov/...PMC3493689

breast cancer estrogen metabolites 2-OH-estrone 2:16 cancer hormones estrogen

shared by Nathan Goodyear on 11 Sep 15 - No Cached
  • These results demonstrate that although 16α-OHE1 was increased more by E+P than by E-alone, the increase in the 2:16 ratio was similar for both HT regimens, due to ~4-fold greater increase in 2OHE-1 than 16α-OHE1 for both HT regimens
  • baseline and 1 year change in 16α-OHE1 showed little relationship to incident breast cancer
  • higher baseline 2-OHE1 and the 2:16 ratio were modestly associated with higher odds of incident breast cancer, but larger 1 year increase in 2-OHE-1 and the 2:16 ratio were also weakly associated with lower odds of breast cancer
  • Nathan Goodyear on 11 Sep 15
     
    Good review of the data from the WHI-HT on estrogen metabolites and breast cancer risk.  Increased 2-OHestrone and 2:16 ratio without statistical significance reached.
Nathan Goodyear

Urinary estrogen metabolites in women at high risk for breast cancer - 0 views

carcin.oxfordjournals.org/...1532.full

breast cancer CA estrogen metabolism 2:16 OHE 2-OH-estrone 16-alpha-OH-estrone

shared by Nathan Goodyear on 10 May 12 - No Cached
  • obesity has also been linked to preferential estrogen metabolism via the 16-alpha-hydroxylation pathway; thus, a prediction of the mechanism by which obesity could increase breast cancer risk would be through a lowering of the 2:16 ratio in favor of the 16 pathway
  • increased BMI was associated with a lower 2:16 OHE ratio
  • Our data show a significant association between alcohol use, defined as at least one drink per day or an average of seven per week, and 2:16 OHE ratio
  • ...10 more annotations...
  • An alcohol-induced rise in estrogens as a consequence of alcohol catabolism in the liver has been reported
  • The only study that looked at the association between alcohol and wine consumption in healthy women did not report a clear association
  • smoking has been reported to increase induction of the 2-hydroxylation metabolic pathway (24). However, the few epidemiological studies conducted on healthy women showed no difference in estrogen metabolites with smoking status (22) or smoking dose (20), in line with our findings.
  • Family history of a first-degree family member with breast cancer confers a 2- to 4-fold risk of developing breast cancer
  • 16% of breast cancers are due to unidentified hereditary factors
  • Estrogen metabolism occurs through enzymes whose activity is determined by the presence of specific genetic polymorphisms, thus can be defined as unique to each individual.
  • the metabolism is also influenced by a number of environmental factors, which change over a lifetime
  • significantly lower 2:16 OHE ratio in women who have known breast cancer risk factors compared with healthy women
  • There was an additional significant association specifically with BMI and alcohol use, which also supports the evidence that these factors affect estrogen metabolism
  • Profiling estrogen metabolites may identify women who are more likely to develop breast cancer within a population of women with known risk factors
  • Nathan Goodyear on 10 May 12
     
    urinary estrogen metabolites shown to provide insight into breast cancer risk.  This study suggested that a low 2:16 OHE ratio increase breast cancer risk.
Nathan Goodyear

Postmenopausal circulating levels of 2- and 16α-hydroxyestrone and risk of en... - 0 views

www.ncbi.nlm.nih.gov/...PMC3241553

estrogen metabolism 2-hydroxyestrone 4-hydroxyestrone estrogen metabolites cancer uterine cancer endometrial cancer hormones 2:16alpha-OHE1 2:16

shared by Nathan Goodyear on 07 Oct 15 - No Cached
  • our results do not support the hypothesis that greater metabolism of oestrogen via the 2-OH pathway, relative to the 16α-OH pathway, protects against endometrial cancer. Indeed our results are more suggestive of an increase in risk, rather than a decrease, with higher levels of 2-OHE1
  • women with a higher 2-OHE1 : 16α-OHE1 ratio did not have a decreased risk of endometrial cancer as compared with women with a lower ratio
  • The findings from this first prospective epidemiological study of oestrogen metabolites and endometrial cancer are in line with results from prospective studies on breast cancer, another oestrogen-related cancer. None of the seven studies on breast cancer reported significant associations overall
  • ...4 more annotations...
  • On the whole, prospective epidemiological data do not support the hypothesis that the 2-hydroxyestrogen pathway is protective, and the 16α-hydroxyestrogen pathway harmful, in hormone-dependent cancers
  • Both 2- and 4-hydroxyestrogens are catecholestrogens, and it has been suggested that catecholestrogens increase risk of oestrogen-mediated cancers through direct genotoxic effects, rather than through stimulation of cell proliferation via binding to oestrogen receptors
  • the evidence is stronger for 4-hydroxyestrogens than for 2-hydroxyestrogens
  • a significant increase in risk of breast cancer with levels of 2-OHE1 has also been reported previously, although it was limited to hormone receptor-negative tumours
  • Nathan Goodyear on 07 Oct 15
     
    2:16 hydroxyestrone ratio not associated with uterine cancer risk.
Nathan Goodyear

Leptin and Androgens in Male Obesity: Evidence for Leptin Contribution to Reduced Andro... - 0 views

press.endocrine.org/...jcem.84.10.6082

obesity leptin low T low Testosterone Testosterone low T leydig cells LH leutenizing hormone men male hormones hormone

shared by Nathan Goodyear on 04 Sep 14 - No Cached
  • in male obesity basal and LH-stimulated androgen levels are reduced and inversely correlated with circulating leptin
  • functional leptin receptors are present in rodent Leydig cells
  • it is conceivable that in males high leptin concentrations may have a direct inhibitory effect(s) on Leydig cell function.
  • ...18 more annotations...
  • insulin is an important inhibitor of the synthesis of SHBG
  • no correlation between leptin and SHBG levels
  • SHBG reduction in obesity is a minor determinant of lowered androgen levels
  • SHBG can explain only up to 3% of the correlation
  • testicular T de novo production is impaired in obese men and that leptin seems to be the best hormonal predictor of this blunted response to LH stimulation
  • The low basal 17-OH-P levels found in massively obese men are consistent with a global impairment of Leydig cell steroidogenic function in this group of subjects.
  • These findings indicate that obese men have a FM-related defect in the enzymatic conversion of 17-OH-P to T, which is revealed by hCG stimulation.
  • Other studies have investigated the adrenal function in male obesity and have shown that basal cortisol and 17-OH-progesterone levels tend to decrease with the increase in the degree of obesity
  • High E2 can inhibit the expression and activity of the 17,20-lyase and may be responsible for this steroidogenic lesion
  • However, stimulated E2 levels were not higher in the obese than in controls, excluding the fact that the lower androgen response was due to an increased aromatization of T to E2 and that estrogens have a major role in the observed defect of 17,20-lyase activity in obese men.
  • the percentage increase in the 17-OH-progesterone to T molar ratio paralleled the increase in leptin levels of obese men
  • Multiple regression analysis indicated that the best hormonal predictor of the obesity-related reduction in T and FT basal levels and androgen changes after hCG stimulation was serum leptin concentration
  • insulin has no negative influences on androgen production in obese men
  • insulin is known to have stimulatory actions on T production that have been demonstrated in obese and normal weight men (57) and in Leydig cells in culture
  • the negative correlation between insulin and basal T can be partly explained by the inhibitory action of insulin on SHBG production
  • hypogonadal men have higher circulating leptin levels compared with hypogonadal patients under effective androgen substitution therapy
  • The impaired androgen response to LH stimulus was due to a defect in the enzymatic conversion of 17-OH-progesterone to T, which was disclosed by a leptin-related increase in 17-OH-progesterone to T ratio
  • Estrogens, which are inhibitory modulators of LH pulsatility and bioactivity
  • Nathan Goodyear on 04 Sep 14
     
    Leptin appears to be a good marker of low Testosterone.  This study proposes that the mechanism of action is potentially 2 fold: first, a decrease in LH release by leptin (kisspeptin?) and 2nd, a directed decrease in Testosterone production by the leydig cells in the testes.
Nathan Goodyear

Estrogen metabolite ratio: is the 2-OH estrone to 16alph-OH estrone ratio predictive of... - 0 views

www.ncbi.nlm.nih.gov/...ijwh-3-037.pdf

estrogen metabolism cancer breast prostate metabolites 2-OH estrone 16alpha-OH

shared by Nathan Goodyear on 17 Feb 12 - No Cached
  • Nathan Goodyear on 17 Feb 12
     
    This is a recent review of the literature regarding estrogen metabolism. It has been proposed that 2:16 OH estrone ratio is predictive of breast, prostate cancer. This study does not find that association
Nathan Goodyear

Estrogen metabolite ratio: Is the 2-hydroxyestrone to 16α-hydroxyestrone rati... - 0 views

www.ncbi.nlm.nih.gov/...PMC3039007

breast cancer 2-OH-estrone 2-OH 4-OH 2:16alpha-OHE1 2:16 estrogen metabolism

shared by Nathan Goodyear on 02 Jan 13 - No Cached
  • A recent study of nine patients concluded that the urinary EMR is a good approximation for breast tissue EMR
  • A single study in young women not using oral contraceptives found fair correlation coefficients between urinary and plasma EMR
  • All of nine properly designed epidemiological studies (six prospective case-control studies and three retrospective studies) failed to show a significant relationship between urinary or circulating EMR (2OHE1/16αOHE1) and breast cancer risk
  • ...2 more annotations...
  • premenopausal studies on urinary EMR have suggested a potentially weak inverse relationship, associations were not significantly different compared with postmenopausal or overall combined studies
  • at present, there is no evidence that the EMR can predict breast cancer risk
  • Nathan Goodyear on 02 Jan 13
     
    The 2:16 OH estrone pathway is shown to not be predictive biomarker for breast cancer.
Nathan Goodyear

Estrogen Metabolism and Risk of Breast Cancer in Postmenopausal Women - 0 views

jnci.oxfordjournals.org/...326.full

estrogen metabolism cancer breast cancer estrogen metabolites

shared by Nathan Goodyear on 16 Jul 15 - No Cached
  • Nathan Goodyear on 16 Jul 15
     
    Get article on estrogen metabolism/metabolites and their effects on the risk of breast cancer in post menopause women.  This article brings to light new information: 2:16alpha estrone ratio is not a great predicted of risk, 2-OH and 4-OH metabolites can form quinone intermediates...
Nathan Goodyear

http://www.researchgate.net/profile/Costanzo_Moretti/publication/12777565_Leptin_and_an... - 0 views

www.researchgate.net/...02bfe50e5334207a93000000.pdf

leptin low T low Testosterone obese men male hormone hormones obesity

shared by Nathan Goodyear on 17 Jun 15 - No Cached
  • Nathan Goodyear on 17 Jun 15
     
    Normal leptin levels are critical to puberty; but in obese men, increased leptin is associated with gonadal decrease in Testosterone.  It appears to occur through a decrease in 17-OH progesterone to Testosterone: suggesting an inhibitory activity in the conversion of 17-OH progesterone to Testosterone in obese men.
Nathan Goodyear

Circulating Estrogen Metabolites and Risk for Breast Cancer in Premenopausal Women - 0 views

www.ncbi.nlm.nih.gov/...PMC3000741

estrogen metabolites estrogen metabolism estrogen 2-OH-estrone 16-alpha-OH-estrone cancer breast cancer women

shared by Nathan Goodyear on 18 Sep 15 - No Cached
  • Nathan Goodyear on 18 Sep 15
     
    no statistical significant association between 2OH-estrone, 16-alpha-OH-estrone, and their ratio found to be associated with increased breast cancer risk in pre menopause women.
Nathan Goodyear

Estrogen Metabolism and Risk of Breast Cancer in Postmenopausal Women - 0 views

www.ncbi.nlm.nih.gov/...PMC3283536

estrogen metabolism estrogen metabolism breast cancer breast cancer

shared by Nathan Goodyear on 14 Oct 13 - No Cached
  • The ratio of the 2-hydroxylation pathway to parent estrogens was associated with a statistically significantly decreased risk of breast cancer
  • In this study, this ratio was more strongly associated with the risk of breast cancer compared with the ratio of 2-hydroxylation pathway to 16-hydroxylation pathway or unconjugated estradiol alone
  • 2-hydroxylation pathway catechols have relatively low affinities for estrogen receptors (4) and are rapidly cleared from circulation
  • ...6 more annotations...
  • In this study, the ratio of the 2-hydroxylation pathway to the 16-hydroxylation pathway was associated with a non-statistically significantly decreased risk of breast cancer
  • In this study, the ratio of catechols to methylated catechols in the 4-hydroxylation pathway was associated with statistically significantly increased risk of breast cancer.
  • This result is consistent with the hypothesis that mutagenic quinones derived from 4-hydroxylation pathway catechols contribute to pathogenesis of postmenopausal breast cancer.
  • Catechols in both the 2- and 4-hydroxylation pathways can be oxidized to form quinones; these reactive electrophiles can then react with DNA to form a variety of adducts
  • Methylation of the catechols prevents their conversion to reactive quinones
  • the most common DNA adducts derived from 4-hydroxylation pathway catechols are depurinating and highly mutagenic (7,40), most of those derived from 2-hydroxylation pathway catechols are stable and can be repaired with little error
  • Nathan Goodyear on 14 Oct 13
     
    Lower 2-OH estrone metabolism associated with lower risk of breast cancer, but 4-OH estrone associated with increased risk of breast cancer.
Nathan Goodyear

Estrogens and Their Genotoxic Metabolites Are Increased in Obese Prepubertal Girls: The... - 0 views

press.endocrine.org/...jc.2015-1495

obesity fat Estrogen hormones hormone Estradiol 16-alpha-OH-estrone 16alpha-OH-estrone estrogen metabolites IL-6 inflammation

shared by Nathan Goodyear on 24 Jun 15 - No Cached
  • Nathan Goodyear on 24 Jun 15
     
    Obesity in young girls increases Estradiol production compared to thin young girls.  Obesity increased  the Estrogen metabolite 16lpha-OH-E1  and this positively correlated with IL-6. 
Nathan Goodyear

High-Dose Vitamin C for Cancer Therapy - PMC - 0 views

www.ncbi.nlm.nih.gov/...PMC9231292

vitamin C cancer

shared by Nathan Goodyear on 27 Jul 22 - No Cached
  • diabetes [8], atherosclerosis [9], the common cold [10], cataracts [11], glaucoma [12], macular degeneration [13], stroke [14], heart disease [15], COVID-19 [16], and cancer.
  • 1–5% of the Vit-C inside the human cells
  • interaction between Fe(II) and H2O2 produces OH− through the Fenton reaction
  • ...35 more annotations...
  • metabolic activity, oxygen transport, and DNA synthesis
  • Iron is found in the human body in the form of haemoglobin in red blood cells and growing erythroid cells.
  • macrophages contain considerable quantities of iron
  • iron is taken up by the majority of cells in the form of a transferrin (Tf)-Fe(III) complex that binds to the cell surface receptor transferrin receptor 1 (TfR1)
  • excess iron is retained in the liver cells
  • the endosomal six transmembrane epithelial antigen of the prostate 3 (STEAP3) reduces Fe(III) (ferric ion) to Fe(II) (ferrous ion), which is subsequently transferred across the endosomal membrane by divalent metal transporter 1 (DMT1)
  • labile iron pool (LIP)
  • LIP is toxic to the cells owing to the production of massive amounts of ROS.
  • DHA is quickly converted to Vit-C within the cell, by interacting with reduced glutathione (GSH) [45,46,47]. NADPH then recycles the oxidized glutathione (glutathione disulfide (GSSG)) and converts it back into GSH
  • Fe(II) catalyzes the formation of OH• and OH− during the interaction between H2O2 and O2•− (Haber–Weiss reaction)
  • Ascorbate can efficiently reduce free iron, thus recycling the cellular Fe(II)/Fe(III) to produce more OH• from H2O2 than can be generated during the Fenton reaction, which ultimately leads to lipid, protein, and DNA oxidation
  • Vit-C-stimulated iron absorption
  • reduce cellular iron efflux
  • high-dose Vit-C may elevate cellular LIP concentrations
  • ascorbate enhanced cancer cell LIP specifically by generating H2O2
  • Vit-C produces H2O2 extracellularly, which in turn inhibits tumor cells immediately
  • tumor cells have a need for readily available Fe(II) to survive and proliferate.
  • Tf has been recognized to sequester most labile Fe(II) in vivo
  • Asc•− and H2O2 were generated in vivo upon i.v Vit-C administration of around 0.5 g/kg of body weight and that the generation was Vit-C-dose reliant
  • free irons, especially Fe(II), increase Vit-C autoxidation, leading to H2O2 production
  • iron metabolism is altered in malignancies
  • increase in the expression of various iron-intake pathways or the downregulation of iron exporter proteins and storage pathways
  • Fe(II) ion in breast cancer cells is almost double that in normal breast tissues
  • macrophages in the cancer microenvironment have been revealed to increase iron shedding
  • Advanced breast tumor patients had substantially greater Fe(II) levels in their blood than the control groups without the disease
  • increased the amount of LIP inside the cells through transferrin receptor (TfR)
  • Warburg effect, or metabolic reprogramming,
  • Warburg effect is aided by KRAS or BRAF mutations
  • Vit-C is supplied, it oxidizes to DHA, and then is readily transported by GLUT-1 in mutant cells of KRAS or BRAF competing with glucose [46]. DHA is quickly converted into ascorbate inside the cell by NADPH and GSH [46,107]. This decrease reduces the concentration of cytosolic antioxidants and raises the intracellular ROS amounts
  • increased ROS inactivates glyceraldehyde 3-phosphate dehydrogenase (GAPDH)
  • ROS activates poly (ADP-ribose) polymerase (PARP), which depletes NAD+ (a critical co-factor of GAPDH); thus, further reducing the GAPDH associated with a multifaceted metabolic rewiring
  • Hindering GAPDH can result in an “energy crisis”, due to the decrease in ATP production
  • high-dose Vit-C recruited metabolites and increased the enzymatic activity in the pentose phosphate pathway (PPP), blocked the tri-carboxylic acid (TCA) cycle, and increased oxygen uptake, disrupting the intracellular metabolic balance and resulting in irreversible cell death, due to an energy crisis
  • mega-dose Vit-C influences energy metabolism by producing tremendous amounts of H2O2
  • Due to its great volatility at neutral pH [76], bolus therapy with mega-dose DHA has only transitory effects on tumor cells, both in vitro and in vivo.
Nathan Goodyear

Vitamin D is associated with testosterone and hypogonadism in Chinese men: Results from... - 0 views

www.ncbi.nlm.nih.gov/...PMC4504177

vitamin d male hormones low T low Testosterone Testosterone

shared by Nathan Goodyear on 09 Jan 17 - No Cached
  • lower 25(OH)D level was significantly associated with lower total T, E2, SHBG, LH and FSH levels after adjusting for age, residence area, economic status and current smoker
  • association between 25(OH)D status and hypogonadism in Chinese men and confirms that this relationship is present in a large population
  • VDR knockout mutant mice showed gonadal insufficiencies
  • ...6 more annotations...
  • High LH and FSH levels in the male mice indicated hypergonadotropic hypogonadism
  • Another mouse study reported a tendency towards low testosterone/LH ratio and Leydig cell hyperplasia in VDR null mice
  • The serum testosterone levels could increase to normal values in vitamin D-deficient rats replete with vitamin D
  • VDR knockout mice had decreased sperm count, reduced sperm motility, and histological abnormality of the testis
  • vitamin D supplementation increases testosterone levels in non-diabetic subjects
  • The data from the European Male Ageing Study [9] indicated that 25(OH)D is positively associated with total T
  • Nathan Goodyear on 09 Jan 17
     
    Study of 713 Chinese men finds a correlation between low vitamin D and low total Testosterone.
Nathan Goodyear

Serum 17-hydroxyprogesterone strongly correlates with intratesticular testosterone in g... - 0 views

www.ncbi.nlm.nih.gov/...PMC2674872

17-hydroxyprogesterone 17-OH progesterone ITT intratesticular testosterone HCG

shared by Nathan Goodyear on 15 May 12 - No Cached
  • Nathan Goodyear on 15 May 12
     
    as the title states: 17-OH progesterone is an appropriate tool to follow ITT levels in those on HCG therapy.
Nathan Goodyear

Myocardial infarction is inversely associate... [Int J Epidemiol. 1990] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...2262248

CAD CVD vitamin D) 25 OH MI heart attack

shared by Nathan Goodyear on 29 Jun 12 - No Cached
  • Nathan Goodyear on 29 Jun 12
     
    Vitamin D (25 OH) below 34 ng/ml associated with double risk of MI.
Nathan Goodyear

Long-Term Bioavailability After a Single Oral or Intramuscular Administration of 600,00... - 0 views

jcem.endojournals.org/...2709.abstract

Vitamin D D3 vitamin 25-OH D

shared by Nathan Goodyear on 22 Jul 13 - No Cached
  • Nathan Goodyear on 22 Jul 13
     
    This study is misleading.  Their conclusion is that D2 and D3 are equivalent in raising 25-OH vitamin D via po form preferentially over the IM form. However, when you look at the results, the response of D3 was statistically significant over that of D2.  That is the conclusion: vitamin D3 is the optimal form of vitamin D.
Nathan Goodyear

Meta-analysis of Vitamin D Sufficiency for Improving Survival of Patients with Breast C... - 0 views

ar.iiarjournals.org/...1163.long

Vitamin D vitamin D cancer breast cancer survival inflammation

shared by Nathan Goodyear on 17 Sep 14 - No Cached
  • Higher serum 25(OH)D concentrations were associated with lower fatality rates in patients with breast cancer
  • Patients with the highest concentration of 25(OH)D had approximately half the fatality rate compared to those with the lowest concentration
  • According to this hypothesis, the growth of a tumor may be arrested at almost any point in the DINOMIT model by restoring a high serum 25(OH)D concentration in the organism, resulting in up-regulation of E-cadherin and restoration of a well-differentiated state
  • ...1 more annotation...
  • Laboratory studies have demonstrated anticancer effects of vitamin D metabolites on three critical phases in the development of breast tumors: differentiation, apoptosis, and angiogenesis
  • Nathan Goodyear on 17 Sep 14
     
    Higher vitamin D levels associated with lower death rates from breast cancer.  In fact, people with the highest levels of vitamin D had death rates cut in half.  The authors point to 3 ares that vitamin D has a positive effect against cancer: differentiation, apoptosis, and angiogenesis.
Nathan Goodyear

Estrogen metabolite ratio: Is the 2-hydroxyestrone to 16α-hydroxyestrone rati... - 0 views

www.ncbi.nlm.nih.gov/...PMC3039007

breast cancer risk 2:16alpha-OHE1 estrogen metabolism ratio

shared by Nathan Goodyear on 23 Aug 11 - No Cached
  • Nathan Goodyear on 23 Aug 11
     
    in this study, estrogen metabolite ratio of 2:16alpha-OHE1 was found to not be predictive of breast cancer risk
Nathan Goodyear

Estrogen Metabolism and Breast Cancer : Epidemiology - 0 views

journals.lww.com/...lism_and_Breast_Cancer.15.aspx

estrogen metabolism estrogen metabolism estrogen metabolite metabolite metabolites breast cancer 2-OH-estrone 16alpha-OH-estrone 2:16alpha-OHE1

shared by Nathan Goodyear on 21 Aug 14 - No Cached
  • Nathan Goodyear on 21 Aug 14
     
    Maybe the risks of estrogen metabolism is age dependent?  This Long Island Breast Cancer Study Project found that an increased 2:16alphOH-estrone ratio was associated with a reduced premenopausal, invasive breast cancer risk.  This association declined when looked at in postmenopausal women.
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