Where I do absolutely agree is that just because somebody is within the reference range, doesnt mean that his symptoms are
- all in the persons head
- or definitly not coming from the ‘normal’ T.
I do absolutely agree that a borderline low free T in combination with symptoms or androgen deficiency can and should be experimentally treated by TRT.
The reference values are after all just statistics and its impossible to accurately separate T deficient from non-deficient men. Its a guiding principle, not a black or white decision.
Many men below 300 are absolutely fine and have no symptoms at all, whereas some men with 450 might already experience symptoms. One study showed that about 50% of men with a free T of 5ng/dl (which is really low) are free of any symptoms. One just has to accept that men coming to this forum and seeking for help are rather the outliers than the majority.
Where i do strongly disagree - and this is my main point that I want to make - is, that somebody (whoever this might be) is intentionally lowering the lower reference level just to deny access to TRT or to ‘fake’ the health or sickness of todays men.
Regarding the reference range used by Quest:
The ref range is based on the Massachusatts Male Ageing study (Mohr et al., 2005).
They used an immuno assay type of assay which resulted in a reference range of 250 to 913 ng/dl. Why Quest uses an upper limit 1100 ng/dl I dont know.
The new reference range by Travison used exactly the same population (among others) and basically arrived at the same ref range.
http://www.imperialendo.co.uk/mohr.pdf
The upper range isnt that important as there are no negative health consequences to be expected between 900 and 1500 ng/dl.
From the quest homepage regarding the lower limit:
Question 8. What is the lower limit of the total testosterone adult male reference range?
There is no universally accepted lower limit. Studies have used different methods, different populations, different times of the day for specimen collection, and different statistical methods. The Quest Diagnostics assays have a reportable lower limit of 250 ng/dL which is consistent with that reported by other laboratories. This is based on the 2.5th percentile of a distribution of results, the approach used to define most reference ranges. In a study by Mohr et al. (2005), the 2.5th percentile for men in their 40s was 251 ng/dL virtually identical to what is commonly reported by laboratories.
Thats also the difference between the Quest and the LabCorp ref range. LabCorp used the ref range based on Bhasin with a lower limit of around 350. This value was artificially ‘high’ because Bhasin used a LC-MS method with a different calibrant that now the CDC recommends.
Quest uses and has always used the ref range based on Mohr which is more in agreement with the LC-MS results of Travison, altough they used different methods. But that the reason LabCorp changed their (lower) ref range and Quest did not.