Views & Reviews From the Frontline

Bad medicine: thyroid disease

BMJ 2012; 345 doi: (Published 09 November 2012) Cite this as: BMJ 2012;345:e7596

Re: Bad medicine: thyroid disease

The breast cancer issues are very different – for a start it is a positive screening program whereas in matters thyroid it is sometimes difficult to even persuade a doctor to do a test.

Subclinical hypothyroidism by your definition is often undiagnosable. Many NHS labs will not perform any thyroid hormone tests when TSH is within reference range – at least at GP level. So you simply cannot know that the thyroid hormone levels are normal. Further, any form of T3 test is often refused by labs.

And, as with so much testing, the definition of normal for a population does not necessarily correspond with normal for an individual. And there do seem to be significant variations in thyroid levels between individuals.

For all the arguments over testing and interpretation, at least there are tests. Somehow anti-depressant prescribing seems also to be rising apace and I don’t remember anyone being given a serotonin test before fluoxetine is prescribed.

Having seen two cases very close to me, the idea of not detecting as early as possible is abhorrent. One case ended up with a massively raised TSH. She wasn’t so much subclinical as seriously myxoedematous. A case that Dr Richard Asher would have diagnosed at a glance.

What seems to be missed in thyroid diagnosis is that every single cell of the body can be affected. So the symptoms, though individually often mild and non-specific eventually become quite clear pointers. It is very often taking a collection of apparently disparate symptoms and realising that they can all be explained by hypothyroidism that supports diagnosis after a blood test. But it seems all too rare for this to be realised before a blood test and used to suggest testing.

In the second close case, my own, the list of symptoms included mild insomnia, changes to vision, plantar fasciitis, hair changes, dry skin, slight breathlessness, reduced stamina, impaired concentration and memory, feeling below par, and many others. And in hypothyroidism, damage to the body accumulates. Add another year before treating that that is another year’s worth of damage that needs to be repaired – if, indeed, that is even possible.

Neither patients nor doctors understand hypothyroidism. Visit Thyroid Manager and see how many questions are posed. It is all too frequent that “crude medical replacement” is mistaken for adequate treatment. But even that is so very often better than leaving the person to deteriorate. Isn’t that more of an argument in favour of reducing the crudity of current medical replacement by, perhaps, looking at options other than once-a-day levothyroxine?

A bit of wood strapped to a broken leg is crude. So if a decent plaster cast is not available should we not even bother with the wood?

And as for the lifelong issue, well I have read of all too many people who have stopped taking their levothyroxine – because they do not understand its importance, because they cannot remember, because they feel it is poisoning them – and it is sometimes only when they have tried to survive without that they realise their true need. But some do stop because they no longer need. If this is indeed a problem then it again suggests that more sophisticated management is needed – not that no treatment is required.

If you were to subscribe to PubMed and get links to all new thyroid-related papers you would get at least ten a day – sometimes many more. So in this flood of papers, why is the epidemiology poorly studied? It certainly is not the fault of the subclinical patients. It must be that those in whom the trust of patients is vested are failing to perform this research.

That statistics show no benefit is perhaps not surprising. The collection of statistics from real thyroid patients about what changes in their health is simply not performed. There really is no patient feedback worth the name. I absolutely claim many benefits but doubt any of them will be reflected in numbers. And my TSH had risen from 2.6. to out of local range over around two years – a nice steady rise. So it was not going to reverse within two years, was it?

I am not sure how you are interpreting the prescribing statistics – is that a doubling of the number of patients being prescribed thyroxine? When I have looked at the same sources it has been easy enough to see part of the story but seemed impossible to translate back into patient numbers. The reasons for this include the need for multiple tablets at many doses, the enforcement of 28-day prescribing, the increased recognition of the need for thyroid hormone dosages to be incremented in pregnancy, and probably several other factors.

Why cannot any real rise in patents taking thyroid hormones have occurred for positive reasons? Either increased valid identification of people who will benefit. Or an absolute increase in hypothyroidism. We have many factors which might be contributing to this: reduced selenium intake due to switching away from north American wheat, possible reduced iodine intake due, in part, to changes to teat disinfection in dairy, possible increases in endocrine disrupting compounds in our environment. To write “the only conclusion” is, I believe, a misinterpretation. There are many possibilities.

Finally, is it not peculiar in the light of your assertion re the “worst medicine” that, in thyroid treatment, we seem to have more GMC cases arising from allegations by doctors (not patients) of inappropriate treatment than mis-diagnosis?

Competing interests: No competing interests

12 November 2012
Rod Hewitt
High Wycombe HP13