This paper forms part of the evidence base for the current NHS thyroid treatment guidelines , it was referenced as evidence to back up their concerns about "low TSH /overtreatment with levo/ risk to bones and heart"
( so they cannot say it is 'not good enough evidence' when you put it under their nose).
However when read carefully ,it actually says that 'low but not supressed' TSH 0.04 - 0.4 on levo had no greater risks than TSH 'in range' does . The risks did increase sharply when TSH was below 0.04 ...
SO .....you can use this paper as a very strong argument that TSH 'itself' is not a increased risk for Fractures / Dysrhythmias (Atrial Fibrilation) / Cardiovascular Disease .... AS LONG AS YOUR TSH is 0.04 or ABOVE .
It was a large, long term study of 17,000 real patients on levo in Scotland.
academic.oup.com/jcem/artic... Serum Thyroid-Stimulating Hormone Concentration and Morbidity from Cardiovascular Disease and Fractures in Patients on Long-Term Thyroxine Therapy
Robert W. Flynn, Sandra R. Bonellie, Roland T. Jung, Thomas M. MacDonald, Andrew D. Morris, Graham P. Leese
The Journal of Clinical Endocrinology & Metabolism, Volume 95, Issue 1, 1 January 2010,
"Abstract
Context: For patients on T4 replacement, the dose is guided by serum TSH concentrations, but some patients request higher doses due to adverse symptoms.
Objective: The aim of the study was to determine the safety of patients having a low but not suppressed serum TSH when receiving long-term T4 replacement.
Design: We conducted an observational cohort study, using data linkage from regional datasets between 1993 and 2001.
Setting: A population-based study of all patients in Tayside, Scotland, was performed.
Patients: All patients taking T4 replacement therapy (n = 17,684) were included.
Main Outcome Measures: Fatal and nonfatal endpoints were considered for cardiovascular disease, dysrhythmias, and fractures. Patients were categorized as having a suppressed TSH (≤0.03 mU/liter), low TSH (0.04–0.4 mU/liter), normal TSH (0.4–4.0 mU/liter), or raised TSH (>4.0 mU/liter).
Results: Cardiovascular disease, dysrhythmias, and fractures were increased in patients with a high TSH: adjusted hazards ratio, 1.95 (1.73–2.21), 1.80 (1.33–2.44), and 1.83 (1.41–2.37), respectively; and patients with a suppressed TSH: 1.37 (1.17–1.60), 1.6 (1.10–2.33), and 2.02 (1.55–2.62), respectively, when compared to patients with a TSH in the laboratory reference range. Patients with a low TSH did not have an increased risk of any of these outcomes [hazards ratio: 1.1 (0.99–1.123), 1.13 (0.88–1.47), and 1.13 (0.92–1.39), respectively].
Conclusions: Patients with a high or suppressed TSH had an increased risk of cardiovascular disease, dysrhythmias, and fractures, but patients with a low but unsuppressed TSH did not. It may be safe for patients treated with T4 to have a low but not suppressed serum TSH concentration.
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This post deals specifically with the alleged risk to bones.. it links to a recent long term study of patients whose TSH was kept deliberately supressed with levo, long term ( to prevent recurrence of thyroid cancer) ..... it found no significant increase in bone loss with a long term supressed TSH as long as T4 was kept in range.
healthunlocked.com/thyroidu... longterm-subclinical-hyperthyroidism-does-not-affect-bone-density-in-patients-having-had-thyroid-ablation-for-cancer
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This very recent study (Feb 2023) shows that in euthyroid people over 50yrs old , a higher ratio of T3 to T4 is associated with a reduced osteoporosis / fracture risk. And that higher T4 levels are associated with increased risk ... which if you assume the same applies to those taking thyroid hormone, backs up the idea of giving a bit less Levo and adding a bit of T3 will REDUCE their risk of osteoporosis / fracture. ( i think ?.... it's a bit complicated to understand the results , but diogenes has clarified the findings in a reply to the post )
post discussing: healthunlocked.com/thyroidu...
direct link to paper: pubmed.ncbi.nlm.nih.gov/367...
thankyou Mollyfan for finding it .
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For a list of links to other useful discussions on the subject of low TSH/ Risk vs Quality of life ,, please see my reply to this post ( 3rd reply down)
healthunlocked.com/thyroidu... feeling-fine-but-tsh-is-low
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it's possible there are some concerns that having high /over rage fT4 promotes cancer cell proliferation but it's not at all clear yet , it's very recent research...
healthunlocked.com/thyroidu... levothyroxine-monotherapy-and-cancer
some replies in this post discuss the issue & provide links :
healthunlocked.com/thyroidu... /over-range-t4?
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If your GP says , "i have to reduce your dose , because i have to follow the NHS guidelines", then remind them of this bit , it's the first thing said to GP's ,on the first page of the latest NHS (N.I.C.E) guidelines for thyroid disease and management. nice.org.uk/guidance/ng145
" Guideline development process
How we develop NICE guidelines
Your responsibility
The recommendations in this guideline represent the view of NICE, arrived at after careful consideration of the evidence available. When exercising their judgement, professionals and practitioners are expected to take this guideline fully into account, alongside the individual needs, preferences and values of their patients or the people using their service. It is not mandatory to apply the recommendations, and the guideline does not override the responsibility to make decisions appropriate to the circumstances of the individual, in consultation with them and their families and carers or guardian. "
Mainly sticking this here for my own reference to save me writing it out each time i need it.
As always, statistics shows the likelihood but not the individual certainty. Even accepting the findings, they should not hamper the individual patient in making their own decisions in their own circumstances. I would have no quarrel with this, if the findings were placed honestly and not luridly to the patient on presentation. Based on these findings, it should NOT be the case that one is told "your TSH is too low therefore you're going to have heart and bone problems". The likelihood is the expression to convey to a patient. This gives the patient a choice: reduced QoL over life or slightly less lifetime. In addition , " by how much does this add to likelihoods of the same diseases from all causes?" It's a case of potential dictation to patients as to how their lives are to go henceforward.
Thankyou Diogenes.
Couple years ago I actually felt pretty rubbish with suppressed TSH even when my T4 and T3 were in range. Lowered slightly. T4 and T3 didn’t shift much but TSH no longer suppressed and felt much better 🤷🏻♀️
me too josephineinamachine
i did OK with TSH 0.05 ish for many years , with T4 ranging between 60% and 130% (on Levo )
I later became overmedicated on the same dose, ( following menopause) with symptoms of overmedication which were not entirely classic but made me feel absolutely bloody awful .
My TSH at that time had fallen slightly to 0.018... my fT4 at the time was about 120%,, but it had been at that level before without any unpleasant symptoms , sadly no info on fT3 so not very enlightening .
a dose reduction resolved the symptoms i was having .ad TSH went back to it's usual 0.05ish
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~ NOTE FOR EVERYONE ~
This post is NOT a recommendation to HAVE these levels of TSH on Levo ... it will be to low for some people , and some people will experience symptoms of overmedication at these levels of TSH even if their T4 /T3 are still in range.
~ "closer to 1 " is a much better place to 'aim' for initially.
This post is A TOOL for the use of people who feel properly well with TSH at these low levels and have tried a lower dose (properly, for AT LEAST 2 months) ,and found it reduced their quality of life to an unacceptable level .... but their GP is insisting on the the "low TSH risk means i HAVE TO reduce your dose anyway " line .