(01-02-2014, 03:33 PM)ClaraKay Wrote: If the loss of testosterone was made up by an equal amount of estradiol, no bone loss should occur. Therefore, bone loss occurs when the amount of sex hormone, in general, declines in later years.
What's right or wrong in my reasoning?
Total testosterone simply is all testosterone bound and unbound to serum proteins. The serum proteins mainly responsible for transport are SHBG and albumin. So do you mean Total Testosterone TT or Bound Testosterone BT or Free Testosterone FT?
I'll take it as you meant Total, essentially it's like comparing apples to oranges,
This implies that as long as we are seeing an increase in estradiol accompanied by an equal or larger increase in testosterone, we are reaping positive effects, on both fat loss and muscle retention since testerone increases IGF-1, while estradiol prolongs the half-life and effect of the hormone by increasing IGFBP-3 and IGF1-receptor density (20). Without the testosterone increase, it may however increase muscle loss (and potentially increase fat loss further by enhancing apoptosis of fat cells ?).
http://www.bodybuilding.com/fun/losefatnow4.htm
I know, but it correlates!......it's like putting the cart before the horse!
Check out this calculator for FT and BT. You will need TT, SHBG, and Albumin
http://www.issam.ch/freetesto.htm
These calculated parameters more accurately reflect the level of bioactive testosterone than does the sole measurement of total serum testosterone. Testosterone and dihydrotestosterone (DHT) circulate in plasma unbound (free approximately 2 - 3%) ,bound to specific plasma proteins (sex hormone-binding globulin SHBG) and weakly bound to nonspecific proteins such as albumin. The SHBG-bound fraction is biologically inactive because of the high binding affinity of SHBG for testosterone. Free testosterone measures the free fraction, bioavailable testosterone includes free plus weakly bound to albumin.
Does this help?