Podcast - NICE Thyroid Disease Part 1: TFTs and Hypothyroidism

The video version of this podcast can be found here:

·       https://youtu.be/kmIhZKT8SA8

This episode makes reference to guidelines produced by the "National Institute for Health and Care Excellence" in the UK, also referred to as "NICE". The content on this channel reflects my professional interpretation/summary of the guidance and I am in no way affiliated with, employed by or funded/sponsored by NICE.

NICE stands for "National Institute for Health and Care Excellence" and is an independent organization within the UK healthcare system that produces evidence-based guidelines and recommendations to help healthcare professionals deliver the best possible care to patients, particularly within the NHS (National Health Service) by assessing new health technologies and treatments and determining their cost-effectiveness; essentially guiding best practices for patient care across the country.

My name is Fernando Florido and I am a General Practitioner in the United Kingdom. In this episode, I go through a section of the NICE guideline on Thyroid disease: assessment and management [NG145], particularly the section on hypothyroidism, always focusing on what is relevant in Primary Care only.

I am not giving medical advice; this episode is intended for health care professionals; it is only my summary and my interpretation of the guidelines and you must use your clinical judgement.  

Disclaimer:

The Video Content on this channel is for educational purposes and not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen on this YouTube channel. The statements made throughout this video are not to be used or relied on to diagnose, treat, cure or prevent health conditions.

In addition, transmission of this Content is not intended to create, and receipt by you does not constitute, a physician-patient relationship with Dr Fernando Florido, his employees, agents, independent contractors, or anyone acting on behalf of Dr Fernando Florido.

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There is a podcast version of this and other videos that you can access here:

Primary Care guidelines podcast:

·       Redcircle: https://redcircle.com/shows/primary-care-guidelines

·       Spotify: https://open.spotify.com/show/5BmqS0Ol16oQ7Kr1WYzupK

·       Apple podcasts: https://podcasts.apple.com/gb/podcast/primary-care-guidelines/id1608821148

There is a YouTube version of this and other videos that you can access here: 

• The Practical GP YouTube Channel: 

https://youtube.com/@practicalgp?si=ecJGF5QCuMLQ6hrk

The NICE clinical guideline on Menopause: identification and management

[NG23] can be found here:

·       https://www.nice.org.uk/guidance/NG23

The resources consulted can be found here:

Thyroid disease: assessment and management -NICE guideline [NG145] can be found here:

·       https://www.nice.org.uk/guidance/NG145

Transcript

If you are listening to this podcast on YouTube, for a better experience, switch to the video version. The link is in the episode description.

Hello and welcome, I’m Fernando, a GP in the UK. Today we are going to go through the NICE guideline on Thyroid disease, always focusing on what is relevant in Primary Care only.

So let’s jump into it.

We will check TFTs if there is:

●    a clinical suspicion of thyroid disease, bearing in mind that 1 symptom alone may not be indicative of thyroid disease

●    type 1 diabetes or other autoimmune diseases, (but we will not offer testing only because of type 2 diabetes).

●    new-onset AF

●    depression or unexplained anxiety

●    abnormal growth in children and young people, or with an unexplained change in behaviour or school performance.

●    And we will be aware that in menopausal women symptoms of thyroid dysfunction may be mistaken for menopause

We will not test for TFTs during an acute illness unless we suspect the acute illness is due to thyroid dysfunction, because it may affect the test results.

So, what tests do we do as initial screening when thyroid dysfunction is suspected?

This will depend on whether we suspect a primary cause, that is, a cause arising from the thyroid gland, or a secondary cause, that is, a cause arising from the pituitary gland.

So, we will always measure TSH. Then, if a primary cause is suspected in an adult:

●    if the TSH is high, that is, suggestive of hypothyroidism, we will need the free thyroxine (FT4) level

●    if the TSH is low, that is, suggestive of hyperthyroidism, we will need FT4 and free tri-iodothyronine (FT3)

However, if we suspect a secondary cause, that is, pituitary disease, or if we are testing a child or young person, we will need results for both TSH and FT4 and:

●    If the TSH is low, that is, suggestive of hyperthyroidism, we will need FT3

So, in summary, we test TSH and T4 in hypothyroidism but in hyperthyroidism we need to add FT3 too.

We can repeat these tests if symptoms worsen or new symptoms develop (but no sooner than 6 weeks from the most recent test).

We will also ask patients about their biotin intake because a high consumption of biotin from dietary supplements may lead to falsely high or low test results.

Looking at the management, and monitoring different rules may apply to children and young people and given that we are likely to be getting advice from the paediatricians , I will not cover them here. If a recommendation applies to children, I will mention it, but otherwise this episode will focus on adults unless otherwise specifically stated.

So, we are going to cover:

●    Primary hypothyroidism: which is caused by an insufficient hormone production by the thyroid gland. In this situation the TSH is high, and FT4 is low.

●    Subclinical Primary hypothyroidism: This can sometimes happen as a precursor of clinical hypothyroidism and it is when the TSH is high, but FT4 is normal.

So let’s start with the management of primary hypothyroidism

So, for all people with confirmed primary hypothyroidism, that is, when we encounter a high TSH and a low FT4, we will:

Check thyroid peroxidase antibodies (TPOAbs)

But in adults, we will not repeat TPOAbs testing. If the antibody test is positive, it maybe worthwhile mentioning that NICE also recommends testing for coeliac disease in people with a diagnosis of autoimmune thyroid disease.

For the actual management, for both adults and children, we will:

Offer levothyroxine as first-line treatment and we will not routinely offer liothyronine or natural thyroid extract for primary hypothyroidism, either alone or in combination with levothyroxine, because there is not enough evidence that it offers benefits over levothyroxine monotherapy, and the long-term adverse effects are uncertain.

We will start levothyroxine at a dosage of 1.6 micrograms per kilogram of body weight per day (rounded to the nearest 25 micrograms) for adults under 65 with primary hypothyroidism and no history of cardiovascular disease.

However, if they are over 65 or with a history of cardiovascular disease, we will start levothyroxine at a dosage of 25 to 50 micrograms per day with titration

How should we follow-up and monitor primary hypothyroidism?

We will aim to maintain TSH levels within the reference range when treating with levothyroxine. If symptoms persist, we will adjust the dose to achieve optimal wellbeing, but we will avoid using doses that cause TSH suppression or thyrotoxicosis.

We also need to be aware that the TSH level can take up to 6 months to return to normal for people who had a very high TSH or a prolonged period of untreated hypothyroidism.

In terms of monitoring, we will need to measure TSH every 3 months until the level has stabilised (that is, until we have had 2 similar measurements within the reference range 3 months apart), and then once a year. But we will also check FT4 as well as TSH if they continue to have symptoms on levothyroxine.

Let’s now look at subclinical hypothyroidism

Once we have confirmed subclinical hypothyroidism, with a high TSH and normal FT4, we will also check TPOAbs.

In terms of the management, we will:

take into account features that might suggest underlying thyroid disease, such as, for example, symptoms of hypothyroidism, or raised levels of thyroid autoantibodies.

Consider levothyroxine if the TSH is 10 mlU/litre or higher on 2 separate occasions 3 months apart, monitoring as per in hypothyroidism

We will also consider a 6-month trial of levothyroxine for adults under 65 with subclinical hypothyroidism who have:

●    a high TSH but lower than 10 mlU/litre on 2 separate occasions 3 months apart, and

●    symptoms of hypothyroidism.

If symptoms do not improve after starting levothyroxine, we will recheck the TSH and if the level remains raised, we will adjust the dose. If symptoms persist when TSH is within the reference range, we will stop levothyroxine and continue monitoring.

So, how do we monitor untreated subclinical hypothyroidism and after stopping treatment?

For them, we will check TSH and FT4:

●    once a year if they have features suggesting underlying thyroid disease, such as previous thyroid surgery or raised levels of thyroid autoantibodies, or

●    once every 2 to 3 years if they have no features suggesting underlying thyroid disease.

We have come to the end of this episode. Remember that this is not medical advice and it is only my summary and my interpretation of the guidelines. You must always use your clinical judgement.

Thank you for listening and goodbye.