Thyroid hormones 24 hour urine test

[Jane123]

Can you tell me please why the thyroid hormone 24 hr urine test is not recognised or used by the NHS in many areas. Surely the results given are more accurate when a patient is on many other medications which can affect tsh results. One example is statin medication which I have read can give a lower than reality tsh blood result.

My urine results showed I was very hypothyroid whereas my blood showed subclinical hypothyroid. My 'trial' of levothyroxine has been purely based on blood tsh results. My urine results, done privately, have been totally ignored.

Also, why are checks for vitamins not routinely carried out when tsh is raised. Having the correct levels can make such a difference to how levothyroxine is used in the body.

Regards

Jane

[Dr Petros Perros]

I would suggest that you try and find out from the lab that tested your urine thyroid hormones, what is their reference range based on, what validation tests have they conducted, what are the performance characteristics of the assays they use and what quality controls (internal and external) do they use? Where is the evidence that urine thyroid hormones are a more valid test of the function of the thyroid than serum levels of thyroid hormones measured by a reliable assay?

I have no idea what the above are, I tried once to find out and got no answers. In contrast NHS laboratories are externally accredited, have strict quality assurance and comply with all the rules to ensure that the performance is up to scratch.