After occasionally hearing in different threads/forums that excess thyroid can increase estrogen I looked it up and found the following studies:
The interrelationships between thyroid dysfunction and hypogonadism in men and boys.
Meikle AW1.
Abstract
.... Thyroid hormone is known to affect sex hormone-binding hormonal globulin (SHBG) concentrations. Men with hyperthyroidism have elevated concentrations of testosterone and SHBG. Thyroid hormone therapy in normal men may also duplicate this elevation. In addition estradiol elevations are observed in men with hyperthyroidism, and gynecomastia is common in them as well. In contrast to patients with primary hypothyroidism, men with hyperthyroidism exhibit hyperresponsiveness of LH to GnRH administration and subnormal responses to hCG. Radioactive iodine therapy (RAI) of men treated for thyroid cancer produces a dose-dependent impairment of spermatogenesis and elevation of FSH up to approximately 2 years. ....
http://www.ncbi.nlm.nih.gov/pubmed/15142373
Estrogen metabolism in hyperthyroidism and in cirrhosis of the liver
Abstract
Estrogen metabolism was studied in spontaneous hyperthyroidism (Graves disease) and in alcoholic cirrhosis of the liver. The plasma concentration of estradiol-17β (PCE2) was Increased in men with hyperthyroidism. Although the metabolic clearance rate of estradiol-17β (MCRE2) was reduced, the production rate (PR) of the steroid was increased above normal. The MCRE2 was also decreased in women with hyperthyroidism but the PCE2 and PRE2 was unchanged from normal. The conversion ratio of estradiol-17β (CRE2E1) was increased in both hyperthyroid men and women. The PCE2 was significantly increased in men with cirrhosis of the liver. The MCRE2 was normal and this resulted in an increase in the PRE2 in this disorder. The CRE2E1 was significantly higher than normal. The plasma concentration of estrone (E1) was elevated in men with both disorders.
The present study documents elevated plasma levels of E1 and E2 both in hyperthyroidism and in cirrhosis of the liver and demonstrates that the increased circulating estrogen in cirrhosis is not due to a decreased removal rate of the steroid but rather results from overproduction of the estrogen. The decreased MCR in hyperthyroidism is consistent with an important role of plasma binding protein in regulating estradiol-17β metabolism in this disorder. The normal MCR in cirrhosis suggests that factors other than plasma binding may be of significance in this disease.
http://www.sciencedirect.com/science/article/pii/0039128X75900057
So if one is supplementing thyroid hormone and goes too high, do you run the risk of increasing estrogen?
This is confusing, as Peat and others describes thyroid hormone (esp. T3) as a potent anti-estrogen...
The interrelationships between thyroid dysfunction and hypogonadism in men and boys.
Meikle AW1.
Abstract
.... Thyroid hormone is known to affect sex hormone-binding hormonal globulin (SHBG) concentrations. Men with hyperthyroidism have elevated concentrations of testosterone and SHBG. Thyroid hormone therapy in normal men may also duplicate this elevation. In addition estradiol elevations are observed in men with hyperthyroidism, and gynecomastia is common in them as well. In contrast to patients with primary hypothyroidism, men with hyperthyroidism exhibit hyperresponsiveness of LH to GnRH administration and subnormal responses to hCG. Radioactive iodine therapy (RAI) of men treated for thyroid cancer produces a dose-dependent impairment of spermatogenesis and elevation of FSH up to approximately 2 years. ....
http://www.ncbi.nlm.nih.gov/pubmed/15142373
Estrogen metabolism in hyperthyroidism and in cirrhosis of the liver
Abstract
Estrogen metabolism was studied in spontaneous hyperthyroidism (Graves disease) and in alcoholic cirrhosis of the liver. The plasma concentration of estradiol-17β (PCE2) was Increased in men with hyperthyroidism. Although the metabolic clearance rate of estradiol-17β (MCRE2) was reduced, the production rate (PR) of the steroid was increased above normal. The MCRE2 was also decreased in women with hyperthyroidism but the PCE2 and PRE2 was unchanged from normal. The conversion ratio of estradiol-17β (CRE2E1) was increased in both hyperthyroid men and women. The PCE2 was significantly increased in men with cirrhosis of the liver. The MCRE2 was normal and this resulted in an increase in the PRE2 in this disorder. The CRE2E1 was significantly higher than normal. The plasma concentration of estrone (E1) was elevated in men with both disorders.
The present study documents elevated plasma levels of E1 and E2 both in hyperthyroidism and in cirrhosis of the liver and demonstrates that the increased circulating estrogen in cirrhosis is not due to a decreased removal rate of the steroid but rather results from overproduction of the estrogen. The decreased MCR in hyperthyroidism is consistent with an important role of plasma binding protein in regulating estradiol-17β metabolism in this disorder. The normal MCR in cirrhosis suggests that factors other than plasma binding may be of significance in this disease.
http://www.sciencedirect.com/science/article/pii/0039128X75900057
So if one is supplementing thyroid hormone and goes too high, do you run the risk of increasing estrogen?
This is confusing, as Peat and others describes thyroid hormone (esp. T3) as a potent anti-estrogen...