Excellent article showing minimal cardiac effec... - Thyroid UK

Thyroid UK
108,974 members126,562 posts

Excellent article showing minimal cardiac effects in patients receiving suppressive doses of L-thyroxine


Dear All,

I have been reading up on the effect of suppressing TSH and the risk of cardiac events (as I received this statement from GP and endocrinologist based on my values!).

There is an excellent article by Shapiro et al, showing that patients who are asymptomatic, suppressing TSH below 0.01mcU/ml does not lead to increased cardiac symptoms (mean follow up of these patients 9.2 years!). There was an increased Left Ventricular Mass Index seen in these patients, however this was found to be of no clinical or prognostic importance.

The full article can be found here:


I hope you will find this useful.

I will continue my search and share further evidence.

All the best & thanks :-)

6 Replies

.... and over 20 years ago ! It has been said it takes an average of 14 years for research to reach mainstream practice - so guess they missed this one !

Thank you for posting !

Thanks for posting. I was threatened with heart problems and osteoporosis if I didn't reduce my levo dose because my TSH was below 1 (0.03!) Fortunately, thanks to the good advice from people on this site, I was able to ignore the doc. (T4 and T3 were both low in range) I have had fewer palpitations (in fact none this year) since ploughing my own furrow!

in reply to crimple

And most of my documentation I need to win my battles I have gotten from this site.


Very useful. Tina_Maria. Thanks for posting. I have a pacemaker so TSH can be 0 and not affect me. My Electrophysiologist agrees with this new thinking even for people who don't have pacemakers. This 'myth' about suppressing TSH causeing severe cardiac side effects is greatly exaggerated in my opinion and experience. Unfortunately many doctors and Endos hang onto this belief like it is the 11th Commandment.

in reply to Hidden

Thanks Irina, very interesting to know. There is also the fact that patients who had thyroid cancer deliberately have their TSH suppressed to avoid any further growth and to my knowledge there is no increased risk of cardiac events in this population either. Like many other people here I am so glad that I found this resource and the great advice of many who have been in similar situations. And I will not be bullied again in reducing my dose based on the TSH suppression (when both T4 and T3 were in the normal range!) and spending 6 months feeling absolutely awful. I am in my 5th week now of taking my full dose again and the difference it has made to my wellbeing is remarkable!

in reply to Tina_Maria

Very happy you're doing well. And remember doctors work for US! No bullying allowed. Take care. irina

You may also like...