Group items tagged

Prospective study finds that elevated total and free Estradiol levels in the follicular phase and elevated total and free Testosterone levels in both the follicular and luteal phase are associated with increased breast cancer in women.  The risk is for pre menopause in this study.  This and several other studies point to serious questions about the massive dosing of Testosterone via pellets, injections, and topicals for libido.  We appear to be following the same patter as seen with premarin, provera, now Testosterone in men and this may be the next ball to drop.  Is the Testosterone therapy merely producing an environment that feeds breast cancer?

Injectable testosterone shown to increase Estradiol production and negatively influence the E2:T ratio in older, obese men.  This is no surprise as age and obesity are known to increase aromatase activity.  I am really surprised that no discussion of aromatase inhibition was discussed.

lower Free Testosterone and increased Estradiol through aromatase activity is associated with increased atherosclerosis.  This was monitored with Carotid intima-media thickness.  This study found an increase associated with low free Testosterone and increased free estradiol levels independent of other CVD variables.

Low total Testosterone, low free Testosterone, and low SHBG associated with increased CRP.  Serum total estradiol and free estradiol trended to a positive association, but did not reach statistical significance.

Estradiol found to be associated with Metabolic syndrome in men. This was independent of other confounding variables.  Most men, the excess estradiol comes from increased aromatase activity on testosterone.

Diabetes associated with low serum testosterone.  This study points to a 4.7 fold decrease.  This is accompanied by a 2.9 fold increase in estradiol.  Castration worsened this imbalance by decreasing the testosterone level further.  Likely the low T and increased aromatase activity aid in the development of diabetic renal disease. Numerous studies have shown that testosterone therapy improves glucose homeostasis.

Study finds that higher BMI and insulin levels associated with decline Testosterone levels.  But, so were risperidone and olanzapine in schizophrenic patients.  The association between the medications and the BMI and insulin was less in the meds, but still present.  The risperidone had a greater association with a lower Testosterone.  Increasing estradiol levels correlated with the low Testosterone levels.

study finds high incidence of prostate cancer in those with low Testosterone at the time of biopsy for HGPIN. What is also interesting, is that the authors found a higher SHBG.  It is well known that Estradiol increases SHBG.  It is also well known that Testosterone to Estradiol in the prostate plays a role in prostate cancer.

peripheral aromatase activity and Testosterone to Estradiol production have central HPA axis suppression resulting in decreased LH and FSH and low Testosterone.

Study finds increased risk of sudden MI in men with low Testosterone and elevated Estradiol.  In converse, increased risk is associated with elevated Estradiol in women.

New study shows that obese boys/young men pre and post puberty have up to 50% lower testosterone levels than comparative normal BMI counterparts.  Also of note, estradiol levels were not associated with the low testosterone levels.

cross sectional study finds low vitamin D associated with a decrease in SHBG and an increase in free Testosterone;  a decrease in estradiol and an increase in DHEA was seen in women.  No association with total Testosterone was found.  There are studies that show a direct decrease in testicular Testosterone production in men with low vitamin D and decrease in AR function.

total and bioavailable Estradiol associated with increased hsCRP in men age 40-80.  Bioavailable is calculated with serum calculated free Testosterone and albumin bound Testosterone.

Several flaws with this study. First, the majority of testing done in the meta-analysis was serum--unreliable.  Second, this study flies in the face of many other studies that have shown elevated estrogens contribute to low testosterone in men.  Third, this flies in the face of observation.  I see over and over again, by lowering a male's estrogen level, he in turn will start producing more Testosterone.  And finally, the environmental xenoestrogens have helped to contribute to a all time low of testosterone/infertility rate in men today.

ibuprofen alters genetic expression that results in decreased Testosterone production.

post menopausal estradiol in women associated with pro-inflammatory state.  SHBG was associated with a decrease in the inflammatory cytokine biomarkers.  Postmenopausal women were found to have an increased Testosterone to estradiol ratio.

aromatase inhiibition via anastrozole decreased Estradiol and allowed for an increase in Testosterone production.  Estradiol has a negative feedback at both the hypothalamus and the pituitary.

Rat study finds balance of DHT and estradiol play important role.  The production of DHT removes Testosterone from the pool to make estradiol through aromatase activity.

Estradiol in mice predisposed to Lupus have increased inflammation and characteristics of Lupus.  In contrast, Estradiol in those without predisposition, do not.  Clearly this is an inflammatory signaling problem.  Studies have shown an Interferon gamma signaling deficit in those with Lupus.  Testosterone decreases the above inflammation signaling.

The genesis of cancer is complex.  To simply say that cancer is genetic is both niave and uninformed.  This study displays the complexity of the timing of hormones and cancer genesis.  This rat study found that Estradiol added to Testosterone increased "markedly".  Estrogen plays a role in the genesis of prostate disease.  However, this varies among individuals.  The response of prostate cancer to estradiol appears to change according to the progression of the cancer.