How long should trans females be made to reduce their levels of circulating testosterone should prior to competing in the women competition?

Gooren found that during the first 12 months muscle mass (area) was decreased by 9.4% & hemoglobin levels by 14% in 20 transwomen (M2F trans) treated with an estrogen-based regimen that reduced circulating T concentrations from the male range to the female range.
Conversely, in 17 transmen (F2M transgender) treated for the first time with testosterone for 12 months (which increased circulating testosterone levels to a mean of 31 nmol/L), muscle mass increased by 19.2% and hemoglobin by 15%.
https://t.co/MOZtfh5Raf
The muscle mass findings remained stable between 1 and 3 years after initiation of treatment, although fat mass continued to change between 1 & 3 years of T treatment. although with disproportionately greater effect on muscle strength than on muscle mass.
https://t.co/8rMfUi4brV
This study did not report muscle strength, but other studies of T dose-response relationships for muscle mass and strength show consistently positively correlation,

https://t.co/0SqyneBjPZ…

https://t.co/pgyggiNG2u

https://t.co/0SqyneBjPZ…

https://t.co/A5AVkkShDj
Hence, the muscle mass estimates in these prospective treatment initiation studies in trans individuals likely underestimate the muscle strength gains from...
Elevated T levels where the circulating T markedly exceeds female range to be within the male range as occurs in severe hyperandrogenism of DSD females, poorly controlled transwomen (M2F transgender),..
or transmen (F2M transgender). These effects are also the biological basis of the ergogenic efficacy of androgen doping in women.
In both intersex/DSD and trans individuals, the developmental effects of adult male circulating T concentrations will have established the sex difference in muscle, hemoglobin, & bone, some of which is fixed & irreversible (bone size)....
.& some of which is maintained by the male circulating testosterone concentrations (muscle, hemoglobin).
The limited available prospective evidence from initiation of trans cross-sex hormone treatment suggests that the advantageous increases in muscle & hemoglobin due to male circulating T concentrations....
...are induced or reversed during the first 12mths & the androgenic effects may plateau after time.
This time course is much faster than the somatic effects of male puberty, which evolve over years and for some variables (e.g., peak bone mass) are not complete for up to a decade after the start of puberty.
However, the abrupt hormonal changes induced by medical treatment in intersex/DSD or transgender individuals may be telescoped compared with male puberty where circulating testosterone concentrations increase irregularly and incompletely for some years.
Additional data are available from the unique investigative model of men undergoing castration for prostate cancer. Just as androgen sensitivity to testosterone may differ between tissues...
https://t.co/S2yyg9Xq8j
The time course of offset of androgen effects following withdrawal of male testosterone concentrations may also differ between the major androgen-responsive tissues.
For example, circulating hemoglobin shows a progressive fall for 6 months reaching a nadir and plateau at 12 to 16 months in six studies involving 534 men undergoing medical castration for prostate cancer.
https://t.co/Bcg0PuNNu3
Although these studies of older men with prostate cancer must be extrapolated with caution, age, stage of disease, race, & baseline circulating T concentration did not affect the rate or extent of decline in hemoglobin.
https://t.co/Bcg0PuNNu3

https://t.co/2bii5lMZYy
Comparable longitudinal studies of muscle loss, strength, and performance following castration for prostate cancer are well summarized,
https://t.co/olda0NryXA
Showing progressive loss for 24 months (see Fig. 4).
Further clinical studies to define the time course of changes, mainly offset, in testosterone-dependent effects, notably on muscle and hemoglobin, are badly needed to determine the optimal duration for cross-sex hormone effects in sports.

End
@threadreaderapp please unroll

More from Kirsti Miller

There is little understanding within Australian society of the requirement to and legitimacy of adopting special measures.


Government policy does not acknowledge the applicability to Indigenous people of the right to self-determination. In 1997 the cruel Howard government actively rejected self- determination as the basis of Indigenous policy.

Key reports which make recommendations for redressing Indigenous disadvantage, including the Royal Commission into Aboriginal Deaths in Custody, and Bringing them home, .....

the National Inquiry into the Separation of Aboriginal and Torres Strait Islander Children from Their Families, have ’NOT’  been fully implemented.

Many recommendations, particularly those concerning the application of the principle of self-determination, have been actively rejected.
”No child should ever be forced to live a life that is not theirs, I did and it nearly killed me many times.”


It appears that every time an under-age Transgender person attempts to access medical care to make their lives better conservative people try to say they’re not ready for it.


As an older transgender woman who waited until I my mid 30’s due to those same prevailing attitudes, I feel it’s sad right-wing people are still trotting out those same tired old lines.

According to them, we’re too young to know our gender pre-pubescent and when we start undergoing a puberty which doesn’t align with our gender identity apparently we’re still far too young to access puberty blockers to make the masculinisation process go away.

These people only want us to access medical care after the age of 18 and that’s when it’s far too late for many Trans women, as the whole masculinisation process [which we didn’t want in the first place] has already happened.

More from Society

global health policy in 2020 has centered around NPI's (non-pharmaceutical interventions) like distancing, masks, school closures

these have been sold as a way to stop infection as though this were science.

this was never true and that fact was known and knowable.

let's look.


above is the plot of social restriction and NPI vs total death per million. there is 0 R2. this means that the variables play no role in explaining one another.

we can see this same relationship between NPI and all cause deaths.

this is devastating to the case for NPI.


clearly, correlation is not proof of causality, but a total lack of correlation IS proof that there was no material causality.

barring massive and implausible coincidence, it's essentially impossible to cause something and not correlate to it, especially 51 times.

this would seem to pose some very serious questions for those claiming that lockdowns work, those basing policy upon them, and those claiming this is the side of science.

there is no science here nor any data. this is the febrile imaginings of discredited modelers.

this has been clear and obvious from all over the world since the beginning and had been proven so clearly by may that it's hard to imagine anyone who is actually conversant with the data still believing in these responses.

everyone got the same R
It is simply not correct to point fingers at wind & solar energy as we try to understand the situation in TX. The system (almost) had a plan for weather (almost) like this. 1/x


It relied on very little wind energy - that was the plan. It relied on a lot of natural gas - that was the plan. It relied on all of its nuclear energy - that was the plan. 2/x

There was enough natural gas, coal and nuclear capacity installed to survive this event - it was NOT "forced out" by the wind energy expansion. It was there. 3/x

Wind, natural gas, coal and nuclear plants all failed to deliver on their expectations for long periods of time. The biggest gap was in natural gas! The generators were there, but they were not able to deliver. 4/x

It may be fair to ask why there is so much wind energy in ERCOT if we do NOT expect it to deliver during weather events like this, but that is an entirely different question - and one with a lot of great answers!! 5/x

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