The levels of LH in the ibuprofen group had increased by 23% after 14 d of administration
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Ibuprofen alters human testicular physiology to produce a state of compensated hypogona... - 0 views
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We found an 18% decrease (P = 0.056) in the ibuprofen group compared with the placebo group after 14 d (Fig. 1A) and a 23% decrease (P = 0.02) after 44 d (Fig. 1C). Taken together, these in vivo data suggest that ibuprofen induced a state of compensated hypogonadism during the trial, which occurred as early as 14 d and was maintained until the end of the trial at 44 d
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We first investigated testosterone production after 24 and 48 h of ibuprofen exposure to assess its effects on Leydig cell steroidogenesis. Inhibition of testosterone levels was significant and dose-dependent (β = −0.405, P = 0.01 at 24 h and β = −0.664, P < 0.0001 at 48 h) (Fig. 2A) and was augmented over time
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The AMH data show that the hypogonadism affected not only Leydig cells but also Sertoli cells and also occurred as early as 14 d of administration
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Sertoli cell activity showed that AMH levels decreased significantly with ibuprofen administration, by 9% (P = 0.02) after 14 d (Fig. 1B) and by 7% (P = 0.05) after 44 d compared with the placebo group
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Examination of the effect of ibuprofen exposure on both the ∆4 and ∆5 steroid pathways (Fig. 2B) showed that it generally inhibited all steroids from pregnenolone down to testosterone and 17β-estradiol; the production of each steroid measured decreased at doses of 10−5–10−4 M. Under control conditions, production of androstenediol and dehydroepiandrosterone (DHEA) was below the limit of detection except in one experiment with DHEA
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Measuring the mRNA expression of genes involved in steroidogenesis in vitro showed that ibuprofen had a profound inhibitory effect on the expression of these genes (Fig. 3 B–D), consistent with that seen above in our ex vivo organ model. Taken together, these data examining effects on the endocrine cells confirm that ibuprofen-induced changes in the transcriptional machinery were the likely reason for the inhibition of steroidogenesis.
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Suppression of gene expression concerned the initial conversion of cholesterol to the final testosterone synthesis. Hence, expression of genes involved in cholesterol transport to the Leydig cell mitochondria was impaired
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A previous study reported androsterone levels decreased by 63% among men receiving 400 mg of ibuprofen every 6 h for 4 wk
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We next examined the gene expression involved in testicular steroidogenesis ex vivo and found that levels of expression of every gene that we studied except CYP19A1 decreased after exposure for 48 h compared with controls
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the changes in gene expression indicate that the transcriptional machinery behind the endocrine action of Leydig cells was most likely impaired by ibuprofen exposure.
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Together, these data show that ibuprofen also directly impairs Sertoli cell function ex vivo by inhibiting transcription
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ibuprofen use in men led to (i) elevation of LH; (ii) a decreased testosterone/LH ratio and, to a lesser degree, a decreased inhibin B/FSH ratio; and (iii) a reduction in the levels of the Sertoli cell hormone AMH
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The decrease in the free testosterone/LH ratio resulted primarily from the increased LH levels, revealing that testicular responsiveness to gonadotropins likely declined during the ibuprofen exposure. Our data from the ex vivo experiments support this notion, indicating that the observed elevation in LH resulted from ibuprofen’s direct antiandrogenic action
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AMH levels were consistently suppressed by ibuprofen both in vivo and ex vivo, indicating that this hormone is uncoupled from gonadotropins in adult men. The ibuprofen suppression of AMH further demonstrated that the analgesic targeted not only the Leydig cells but also the Sertoli cells, a feature encountered not only in the human adult testis but also in the fetal testis
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ibuprofen displayed broad transcription-repression abilities involving steroidogenesis, peptide hormones, and prostaglandin synthesis
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a chemical compound, through its effects on the signaling compounds, can result in changes in the testis at gene level, resulting in perturbations at higher physiological levels in the adult human
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The analgesics acetaminophen/paracetamol and ibuprofen have previously been shown to inhibit the postexercise response in muscles by repressing transcription
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Previous ex vivo studies on adult testis have indeed pointed to an antiandrogenicity, only on Leydig cells, of phthalates (41), aspirin, indomethacin (42), and bisphenol A (BPA) and its analogs
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ibuprofen’s effects were not restricted to Leydig and Sertoli cells, as data showed that the expression of genes in peritubular cells was also affected
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In the clinical setting, compromised Leydig cell function resulting in increased insensitivity to LH is defined as compensated hypogonadism (4), an entity associated with all-cause mortality
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compensated hypogonadic men present with an increased likelihood of reproductive, cognitive, and physical symptoms
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an inverse relationship was recently reported between endurance exercise training and male sexual libido
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AMH concentrations are lower in seminal plasma from patients with azoospermia than from men with normal sperm levels
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inhibin B is a key clinical marker of reproductive health (32). The function of AMH, also secreted by Sertoli cells, and its regulation through FSH remain unclear in men
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the striking dual effect of ibuprofen observed here on both Leydig and Sertoli cells makes this NSAID the chemical compound, of all the chemical classes considered, with the broadest endocrine-disturbing properties identified so far in men.
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Antiandrogenic effects of bisphenol A and nonylp... [Toxicol Sci. 2003] - PubMed - NCBI - 0 views
www.ncbi.nlm.nih.gov/...12805653
Bisphenol-A androgen receptor antagonist androgen receptor androgen receptor hormone hormones xenoestrogens xenoestrogen
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Widely used pesticides with previous... [Environ Health Perspect. 2011] - PubMed - NCBI - 0 views
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pesticides low T Testosterone anti-androgens antiandrogens health men's
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Testosterone and the Cardiovascular System: A Comprehensive Review of the Clinical Lite... - 0 views
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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
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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
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In patients with CHF, testosterone replacement therapy has been shown to significantly improve exercise tolerance while having no effect on LVEF
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testosterone therapy causes a shift in the skeletal muscle of CHF patients toward a higher concentration of type I muscle fibers
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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.
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Lower levels of endogenous testosterone have been associated with longer duration of the QTc interval
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negative correlation has been demonstrated between endogenous testosterone levels and IMT of the carotid arteries, abdominal aorta, and thoracic aorta
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These findings suggest that men with lower levels of endogenous testosterone may be at a higher risk of developing atherosclerosis.
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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.
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The Massachusetts Male Aging Study also projects ≈481 000 new cases of hypogonadism annually in US men within the same age group
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since 1993 prescriptions for testosterone, regardless of the formulation, have increased nearly 500%
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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
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A growing body of evidence suggests that men with lower levels of endogenous testosterone are more prone to develop CAD during their lifetimes
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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.
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The biologically inactive form of testosterone is tightly bound to SHBG and is therefore unable to bind to androgen receptors
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The biologically inactive fraction of testosterone comprises nearly 68% of the total testosterone in human serum
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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
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It is estimated that ≈30% of total serum testosterone is bound to albumin, whereas the remaining 1% to 3% circulates as free testosterone
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it can be argued that using the biologically active form of testosterone to evaluate the association with CAD will produce the most reliable results
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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
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patients with catheterization‐proven CAD had statistically significant lower levels of bioavailable testosterone
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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
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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
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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
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the relative risk of all‐cause mortality in men with lower levels of total testosterone was calculated to be 1.35
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higher risk of cardiovascular mortality is associated with lower levels of bioavailable testosterone
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Existing evidence seems to suggest that lower levels of endogenous testosterone are associated with higher rates of all‐cause mortality and cardiovascular mortality
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studies have shown that lower levels of endogenous bioavailable testosterone are associated with higher rates of all‐cause and cardiovascular mortality
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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
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In more recent studies, 3 randomized, placebo‐controlled trials demonstrated that administration of testosterone improves myocardial ischemia in men with CAD
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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.
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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
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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
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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
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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.
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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
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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
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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
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Existing evidence strongly suggests that the levels of total and free testosterone are lower among diabetic patients compared with those in nondiabetics
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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
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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.
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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
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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
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Intima‐media thickness (IMT) of the carotid artery is considered a marker for preclinical atherosclerosis
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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
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1 study has demonstrated that lower levels of free testosterone are associated with accelerated progression of carotid artery IMT
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another study has reported that decreased levels of total and bioavailable testosterone are associated with progression of atherosclerosis in the abdominal aorta
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These findings suggest that normal physiologic testosterone levels may help to protect men from the development of atherosclerosis
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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
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Type I muscle fibers, also known as slow‐twitch or oxidative fibers, are associated with enhanced strength and physical capability
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It has been shown that those with advanced CHF have a higher percentage of type II muscle fibers, based on muscle biopsy
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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.
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Testosterone replacement therapy has been shown to significantly improve exercise capacity, without affecting LVEF
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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
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Data from 3 meta‐analyses seem to contradict the commonly held belief that testosterone administration may increase the risk of developing prostate cancer
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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
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the existing data from the 3 meta‐analyses seem to indicate that testosterone replacement therapy does not increase the risk of adverse cardiovascular events
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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
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the studies that failed to find an association between testosterone and CRP used an older population group
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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
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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.
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Plant-derived 3,3′-Diindolylmethane Is a Strong Androgen Antagonist in Human ... - 0 views
www.jbc.org/...21136.full
DIM I3C PSA AR androgen receptor prostate cancer men male hormone hormones androgen
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DIM has a strong affinity for both the mutant AR inLNCaP cells and for recombinant wild-type human AR
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PSA has been reported to promote the proliferation, migration, and metastasis of prostate cancer cells through several mechanisms, including cleavage of insulin-like growth factor-binding protein-3 and degradation of extracellular matrix proteins fibronectin and laminin
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down-regulation of PSA expression may be important in the antiproliferative effects of DIM in LNCaP cells