Diagnosis and treatment of hyperthyroidism webinar

Understanding treatment options that may be suitable for them is something patients with hyperthyroidism often ask us about. So it was extremely useful to listen to our expert speakers, Dr Earn Gan, consultant endocrinologist, Newcastle and Miss Sheila Fraser, consultant endocrine surgeon, Leeds discuss this at our March 2022 webinar.

This is a transcript of the patient questions answered live by our experts.
Key: Dr Earn Gan – (EG), Miss Sheila Fraser – (SF)

What is the link between thyroid blood tests and symptoms? For example, do higher thyroid antibodies levels determine how symptomatic patients are?

Not always. Higher free thyroid hormones indicate more severe disease but do not always correlate with the severity of symptoms. For example, you can have young people with mild disease who are very symptomatic but older patients who have minimal symptoms despite being much more thyrotoxic*, in  terms of their blood results. So, the level of thyroid hormones is not always in keeping with the severity of the symptoms.

Apart from age, there could be a difference in symptoms between men and women. For example, we see men present with less severe symptoms than women in some cases.

The TSH Receptor Antibody (TRAb) doesn’t directly determine the severity of symptoms. A high TRAb is diagnostic for Graves’ disease and the higher the TRAb level, the greater the immune attack going on in the thyroid.

So it is more likely you would have more severe thyrotoxicosis. It may also mean you are more likely to take longer to respond to anti-thyroid medication or require a much higher dose of anti-thyroid medication to achieve remission. Also, the higher the TRAb level, the greater the likelihood of developing Thyroid Eye Disease (TED). So, it’s fair to say that the TRAb level can indicate whether you are more likely to develop TED but it does not determine the severity of thyrotoxic symptoms. (EG)

How can scans be used to distinguish between Graves’ disease and postpartum thyroiditis?**

We don’t commonly use thyroid ultrasound to determine the cause of hyperthyroidism nowadays. This is because, first of all, an ultrasound scan is not very sensitive in diagnosing these conditions. Secondly, blood thyroid autoantibodies and thyroid uptake scans are more sensitive and specific diagnostic tests.

We only do ultrasound scans, for example, if a patient with hyperthyroidism is found to have a thyroid nodule. Even then we would defer the ultrasound until after the thyrotoxicosis is treated. This is because if you have an overactive thyroid gland, there is a high chance that an ultrasound scan will show some  indeterminate features.

This could lead to unnecessary investigations, such as a biopsy. So, we tend to wait until thyroid function is normal and then we do the scan, unless the thyroid nodule has increased in size or the patient has  obstructive symptoms from a large nodule.

The best test to distinguish between Graves’ disease and postpartum thyroiditis is a blood test. If you have very high TRAb levels then this is Graves’ disease and not postpartum thyroiditis. If the TRAb level is negative, then we would do a thyroid uptake scan.

The other thing I did not talk about earlier in the webinar is that we can predict the likelihood of Graves’ disease or thyroiditis by judging the thyroid hormone levels. We know that thyroid follicles produce/store more T4, so when we look at the ratio between T4 and T3 we will have an idea of whether it is more likely to be Graves’ disease as opposed to thyroiditis. (EG)

I have a TSH of 0.81 and I would like to stay on a low dose (5mg) of carbimazole to avoid becoming hyperthyroid again. Is it a good or bad thing to stay on carbimazole long-term?

It depends on the diagnosis. If this is Graves’ disease, there is essentially a 50% chance of remission and you may not need to stay on tablets for life. If your Graves’ disease relapses and you are now choosing to be on long-term carbimazole, the most important question is whether the thyrotoxicosis is being controlled on carbimazole. If the thyrotoxicosis is not well controlled on carbimazole, then choosing long-term carbimazole is not good for you.

If thyrotoxicosis is controlled and you want to take carbimazole for life, then you need to bear in mind the potential side effects of carbimazole, in particular agranulocytosis.*** We do have some patients who, due to age or comorbidity,**** could not have thyroid surgery and were not keen to have radioiodine therapy, so they chose to have long-term low-dose carbimazole and are absolutely fine. They just have to  bear in mind the potential side effects of being on carbimazole for life. (EG)

How can patients find out how much experience surgeons have of performing thyroid operations so they can be reassured they are in the hands of an experienced surgeon?

I think there is no harm asking your surgeon and we have had quite a lot of people in our unit ask us how many thyroid surgeries we perform; what our complication rate is etc. I think everybody has the right to ask for that. It is very important if you are having any operation that it is the right decision for you and you need to make sure you are going into it aware of risk and complications because you cannot take any operation lightly. And I do not take any Graves’ surgery lightly because it can be more challenging. So when I see a patient, I also want to make sure they have had a full discussion about other types of treatment because sometimes when people hear the term ‘radioactive iodine’ they get put off by this.

So, again, it is making sure they have had that informed discussion about what it actually is and that surgery is right for them. 

I do not think any surgeon would be offended if people say to them: I am worried. It is a big operation to go through. Can I just check how many surgeries you do in this unit, how many surgeons there are and what is your complication rate? are very fair questions. If I were on the opposite side, I would want to know those answers. (SF)

Is there a relationship between either having had Covid or the vaccine and Graves’ disease being triggered or returning?

Yes, the studies are not published yet so it is more about a general feel. Certainly, in 2021, we did see an increase in Graves’ disease but it is hard to tell whether this was due to Covid-19, stress-related, or just pure coincidence. For example, we sometimes see that Graves’ disease is preceded by a shock event, such as bereavement in some patients. Autoimmune disease is a complex interplay between the environment, genetic and individual susceptibility. It remains unclear whether it was the psychological stress from the pandemic, or the Covid-19 virus itself, that has led to more cases of autoimmune thyroid disease.

Essentially, in Graves’ disease, the immune system gets confused and attacks the thyroid gland and Covid-19 may have triggered a similar reaction in the immune response. Hopefully, we will find out the answer in the future. (EG)

What are the risks of a patient having to wait until they see their endocrinologist before being treated?

We see a spectrum of severity and clinical symptoms with hyperthyroidism. The patient could have a lot of symptoms and feel awful when their blood thyroid hormone levels were just slightly high. In these patients, the impact on the heart is significantly less. For those who have very severe thyrotoxicosis i.e. free T4 level of more than 100, their heart would be under strain with risk of heart failure if the disease is not treated early.

Thyroid storm is not a common presentation of hyperthyroidism but the higher the thyroid hormone level,
the more likely this can happen. So, the key thing is to get hyperthyroidism treated as soon as possible. GPs can start beta blockers if the blood results showed hyperthyroidism and this will reduce the strain on the heart and heart rate.

In terms of starting antithyroid drug (e.g carbimazole) in primary care, I personally would say if Graves’ disease is confirmed by the GP (e.g high TRAb level), then anti-thyroid medication can, and should, be  started in primary care.

However, we need to bear in mind that thyroiditis is one of the causes of hyperthyroidism and commonly happens after pregnancy or Covid infection and is usually a self-limiting disease. If you start carbimazole or other antithyroid drugs with this diagnosis, this can prolong the time for full recovery. Hence, I would  not recommend starting carbimazole in every patient with hyperthyroidism when the diagnosis is not yet clear.

It would be very helpful if GPs can have access to TRAb testing. Where I am based in Newcastle, we ask  GPs to start carbimazole straight away if the blood test done at the GP practice shows elevated TRAb with high free thyroid hormones. Waiting times for new patients with hyperthyroidism in our Trust are between 2 to 4 weeks from referral. If patients cannot access endocrinologists as quickly in their area, the GP could discuss the case with local endocrinologists to decide if carbimazole should be started. 

In severe hyperthyroidism, carbimazole should probably be commenced by GPs (even without the TRAb  result) if the biochemical results suggests Graves’ disease (EG) 

Footnotes

*Thyrotoxicosis – too much thyroid hormone in the body. Thyrotoxic = relating to the condition thyrotoxicosis

**Postpartum thyroiditis – this is a form of thyroiditis that occurs after pregnancy especially in women with thyroid autoantibodies. It usually shows up in the first six months after giving birth. As with sub-acute thyroiditis it usually starts with symptoms of an overactive thyroid (hyperthyroidism) that may resolve by itself, or progress to symptoms of an underactive thyroid (hypothyroidism).

The underactive phase may present as postnatal depression. Women usually recover completely in two to five months although in about five per cent of cases there may be permanent underactivity.
Should this happen you will be prescribed levothyroxine (synthetic thyroxine) tablets to replace the missing thyroid hormone.

***Agranulocytosis – the most serious potential side effect of antithyroid drugs is bone marrow  depression causing a lowering of the white blood cells that normally fight infection, a potentially life-threatening condition called agranulocytosis. This is extremely rare and affects a small number of people
usually during the first three months of treatment. The incidence is certainly less than one in 500 and is  possibly as low as one in 3,000.

If you develop a sore throat, mouth ulcers or unexplained fever stop taking the tablets immediately and go to your GP or nearest Accident and Emergency department in order that a full blood count can be carried out.

**** Comorbidity – the simultaneous presence of two or more medical conditions in a patient.

See our hyperthyroidism resources

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