My Dilemma

[testiculus]

Glenn Cunningham, when asked by Dr. Abraham Morgenthaler, where did you come up with 54%? His answer was we actually don't have much data to say anything but we had to pick a number and it seemed like a reasonable number.

This gets back to how much risk is too much risk. It's a judgement call. Hence, whatever number is picked, even if it's done by an "expert" is still that. It's their individual opinion of what is too much risk.

 

[Cataceous]

There are over 80 million people that live higher than 2,500 meters and they develop a secondary erythrocytosis. Men in parts of Bolivia have a normal range of HCT from 45-61%.

These men are not at an increased risk of thrombotic events nor do they have to undergo phlebotomies to manage their hematocrit.

Previously you "liked" the post with this quote:

In contrast, residing at high-altitude locations, especially above 3500 m, is associated with an apparent increased risk [of stroke, or dying from it], probably linked to the presence of polycythaemia and other factors such as increased blood viscosity, and the presence of a hypercoagulable state might increase the risk of developing stroke among those exposed to very high altitudes. It seems clear that short-term exposures to high altitudes are a risk factor for developing a stroke. The available scientific literature suggests that above 3500-4000 m, the risk of developing stroke increases, especially if the exposure is acute among non-adapted populations.​

Could initiating TRT be likened to this "acute exposure"? If so then there's a parallel with the studies finding higher risk at the start of TRT.

I guess you also forgot about the graph @testiculus was alluding to, which makes 54% look less arbitrary:

 

[FunkOdyssey]

I guess you also forgot about the graph @testiculus was alluding to, which makes 54% look less arbitrary:
View attachment 40084

Interestingly, they only have 3 data points between 39 and 54% which are virtually identical and don't fit the curve. It does look like viscosity starts rising after 54% but not before that. Viscosity is slightly lower in the range of 25-38, which would correspond to anemia or toddlers perhaps. Not relevant to healthy adults, so it's unfortunate so many of their data points fell in that abnormally low range.