Official guidelines

[Tanyaking]

Is there any document on any site I can print out that would be recognised by an NHS endocrinologist to suggest that the free Ts should ideally be in the upper third of there reference range?

[SeasideSusie Remembering]

Tanyaking The only one I know of is an article in Pulse Online Magazine (doctors' magazine) written by Dr Anthony Toft who is past president of the British Thyroid Association and leading endocrinologist in which he states

"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.

In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l. Most patients will feel well in that circumstance.

But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."

You can obtain a copy of the article by emailing [e-mail] print it off and highlight question 6.

However, that isn't classed as official guidelines, but Dr Toft should carry some clout.