Paciente de mi consulta con TSH inhibida por un hipotiroidismo secundario tras intervención de adenoma de hipófisis, le reduje las hormonas tiroideas un mes por error, el motivo fue seguir rutina habitual en la monitorización de hipotiroidismos primarios el 99% en atención primaria y no pensar la causa.
Cuidado en la rutina del la monitorización de TSH para cambios de tratamiento en los hipotiroidismos, no es lo mismo el seguimiento de un hipotiroidismo primario, el 95 % de nuestra clínica que el de los hipotiroidismo secundarios y terciarios. No usar la TSH en secundarios y terciarios recordemos la fisiopatología.
En el hipotiroidismo primario, al suprimirse el mecanismo de retroalimentación negativa de la hipófisis, asciende las cifras de TSH superiores a las normales y regularmente por encima de a las 10 microunidades. En los hipotiroidismos secundario y terciario baja a menos de 0,20 o no se la detecta en la sangre. La prueba de la TRH-TSH nos sirven en diagnostico diferencial, en el hipotiropidismo terciario existe lesiones hipotalámicas que anulan la secreción de hormona liberadora de tirotrofina razón por la cual la adenohipófisis deja de producir tirotrofina, pero como solo está hipotrófica y aun es capaz de responder al estímulo trófico, al inyectarse la TRH por vía intravenosa, los niveles basales que estaban en cero o menores que 0,20 microunidades, se elevan a más del 100%. En el hipotiroidismo secundario existe lesiones hipofisarias que anulan las células secretoras de TSH, el hipotálamo es normal y funcionante pero no hay respuesta de TSH por falta de células efectoras de modo que si se inyecta la TRH no se producirá modificación de los valores bajos o nulos de la tirotrofina. Debemos recordar que en el hipotiroidismo primario, la hipófisis se encuentra liberada del freno tiroideo de modo que su estimulación con TRH producirá un aumento aun mayor de los valores de TSH basales, es decir que habrá una hiperrespuesta, superior a la que se verifica en la variedad hipotalámica.
Si tenemos en cuenta que desconocemos los límites de normalidad premórbida de cada paciente, es importante valorar el parámetro analítico junto con la sintomatología clínica e intentar conseguir una concentración de TSH normal. Hay que tener en cuenta también, que las determinaciones analíticas tienen su falibilidad y que una TSH en los límites normales en un paciente que se encuentra bien, esté en el límite bajo o alto de la normalidad, no nos tiene por qué obligar a modificar las dosis que el paciente esté recibiendo. Del mismo modo, si el paciente presenta sintomatología atribuible a hipotiroidismo, la dosis de LT4 puede incrementarse hasta conseguir una concentración de TSH en el límite bajo del margen poblacional normal o incluso por debajo de éste, según algunos autores.
Un caso especial es la paciente en edad gestacional, en la que la T4 libre del primer trimestre es esencial para el desarrollo neurológico del embrión. En la paciente con deseo gestacional y tratamiento con LT4 por hipotiroidismo primario, es importante monitorizar la TSH preconcepción y mantenerla inferior a 2 mUI/l, así como recomendar un aumento de dosis de LT4 en cuanto se conozca el estado de gestación.
¿Cómo monitorizamos el hipotiroidismo secundario donde la concentración de TSH no tiene ningún valor?
En el hipotiroidismo central, la T4 libre disminuye por una alteración hipotálamo-pituitaria en la síntesis de TSH. A diferencia del hipotiroidismo primario, la T4 libre baja pero la TSH se mantiene normal, incluso a veces ligeramente elevada debido a la presencia de formas biológicamente inactivas de TSH. Al iniciar el tratamiento con LT4, la TSH se suprime rápidamente y deja de tener valor en la monitorización del tratamiento. Por tanto, en la práctica clínica nos basamos fundamentalmente en las concentraciones de T4 libre para evaluar la idoneidad del tratamiento.
T4 libre, T3 libre o ambas, y qué concentraciones debemos perseguir
La T4 libre es el parámetro individual más valioso en la monitorización del hipotiroidismo central. Ferreti et al estudiaron 37 pacientes con hipotiroidismo central (3 diagnosticados de novo y 34 a los que suspendieron el tratamiento con LT4); la T4 libre fue baja en todos ellos, pero la T3 libre fue normal en un 27% a los 60 días de haber suspendido el tratamiento con LT4, lo que indica que la concentración de T4 libre es más sensible que la T3 libre en la detección de la infradosificación44. No obstante, la determinación de ambas fue superior que la de T4 libre sola en la detección de casos de tratamiento inadecuado. Por tanto, siempre y cuando sea preciso el ensayo para la determinación de T3, la determinación de T3 libre puede añadir información a la de T4 libre en la monitorización del hipotiroidismo central.. El hipotiroidismo central casi nunca se presenta como entidad aislada, sino en el contexto de hipopituitarismo, con otras alteraciones hormonales asociadas. Hay otras hormonas, como los glucocorticoides y la hormona del crecimiento (GH) que afectan la conversión de T4 a T3. La GH, por ejemplo, estimula la conversión de T4 a T3, por lo que teóricamente en la deficiencia de GH no tratada, la concentración teórica de T4 libre para una misma T3 sería mayor que en sujetos control. En pacientes con hipotiroidismo central nosotros hallamos una relación T3/T4 inferior a la de controles, pero no fue distinta a la de sujetos con hipotiroidismo primario estable tratado .
No olvidemos nunca centrarnos en el paciente que tenemos delante y la fisiopatología de la enfermedad , tanto en el diagnostico como en el seguimiento.
You ought to be a part of a contest for one of the most useful websites on the net.
I will highly recommend this web site!
What i do not understood is in truth how you are not actually much more smartly-liked than you may be right now.
You’re very intelligent. You know thus considerably when it comes to this subject, produced me personally believe it from numerous varied angles.
Its like men and women don’t seem to be fascinated except it’s one thing to do with Girl gaga!
Your personal stuffs excellent. At all times maintain it up!
Every weekend i used to pay a quick visit this site, as i
wish for enjoyment, for the reason that this this web page conations genuinely fastidious funny
material too.
It’s going to be finish of mine day, except before finish I am
reading this impressive article to increase
my experience.
I do not even know how I ended up here, but I thought this post
was good. I don’t know who you are but certainly you’re going to a famous blogger if you aren’t
already 😉 Cheers!
I constantly spent my half an hour to read this blog’s
articles or reviews daily along with a mug of coffee.
Hey there! Would you mind if I share your blog with my facebook group?
There’s a lot of people that I think would really appreciate your content.
Please let me know. Many thanks
Thanks for your marvelous posting! I really enjoyed reading it,
you happen to be a great author. I will ensure that I bookmark your blog and
will come back in the future. I want to encourage you
continue your great posts, have a nice day!
Howdy! This post could not be written any better! Reading this post reminds me of my good old room mate!
He always kept talking about this. I will forward this page to him.
Fairly certain he will have a good read. Thanks for
sharing!
Thanks for any other magnificent article. The place else may just anybody get that
kind of information in such a perfect approach of writing?
I have a presentation next week, and I’m on the search for such info.
May I simply say what a relief to uncover a person that actually
understands what they are discussing online.
You actually understand how to bring an issue to light
and make it important. More people should look at this and understand this side
of your story. It’s surprising you aren’t more popular given that you definitely
possess the gift.
This article offers clear idea in favor of the new users of blogging, that truly how to do blogging.
Hi there, You have done a great job. I will definitely digg it and personally suggest to my
friends. I’m confident they will be benefited from this site.
I got this web site from my buddy who shared with me concerning this web page and at the moment
this time I am browsing this web site and reading very informative content at
this time.
My family members all the time say that I am killing my time here at web,
however I know I am getting familiarity all the time by reading such
nice articles or reviews.
I simply couldn’t go away your site prior to suggesting that I
actually loved the standard info a person provide to your guests?
Is going to be back often in order to inspect new posts
Wow, this paragraph is good, my sister is analyzing such things, thus
I am going to convey her.
I don’t even know how I ended up here, but I thought this post was great.
I don’t know who you are but definitely you’re going to a
famous blogger if you are not already 😉 Cheers!
As the admin of this web site is working, no hesitation very soon it will be renowned, due to its feature contents.
Pretty great post. I just stumbled upon your weblog and wished to mention that I have truly enjoyed surfing around your weblog posts.
After all I’ll be subscribing on your rss feed and I am hoping
you write once more very soon!
I’m not that much of a online reader to be honest but your blogs really nice, keep it up!
I’ll go ahead and bookmark your site to come back later on. Cheers
Just wish to say your article is as surprising.
The clarity in your post is just great and i could assume
you’re an expert on this subject. Well with your permission let me to grab
your feed to keep updated with forthcoming post.
Thanks a million and please continue the gratifying work.
I simply couldn’t leave your website before suggesting that I really loved
the usual information a person provide for your guests?
Is going to be again frequently to check up on new posts
I like the helpful information you supply
on your articles. I will bookmark your blog and check once more right here regularly.
I am somewhat certain I will be informed many new stuff proper here!
Best of luck for the following!
Hello, i think that i saw you visited my weblog so i came to “return the favor”.I am attempting to
find things to enhance my site!I suppose its ok to use some of your
ideas!!
Usually I do not read post on blogs, but I would like to say that this
write-up very pressured me to try and do it! Your writing taste has been amazed me.
Thanks, very nice article.
Fantastic goods from you, man. I’ve bear in mind your stuff prior to
and you are simply too magnificent. I really like what you
have obtained here, really like what you’re stating and
the way in which during which you say it. You are making it entertaining and you still care for to keep it smart.
I can’t wait to learn far more from you. That is actually a
great web site.
I have been browsing online more than 2 hours today, yet
I never found any interesting article like yours.
It is pretty worth enough for me. Personally, if all web owners and bloggers
made good content as you did, the web will be much more useful
than ever before.
What’s Going down i’m new to this, I stumbled upon this
I have discovered It absolutely useful and it has aided me
out loads. I’m hoping to contribute & assist other users like
its helped me. Good job.
Can you tell us more about this? I’d love to find out some additional information.
This is a topic that is near to my heart… Many thanks!
Exactly where are your contact details though?
I was recommended this blog by my cousin. I am not sure whether this post
is written by him as no one else know such detailed about my difficulty.
You’re incredible! Thanks!
Great info. Lucky me I recently found your site by accident (stumbleupon).
I’ve bookmarked it for later!
We are a gaggle of volunteers and opening a brand new scheme in our community.
Your web site provided us with valuable info to work on. You’ve performed a formidable task and our entire neighborhood will be grateful
to you.
whoah this blog is magnificent i really like studying your posts.
Stay up the great work! You know, a lot of
persons are looking around for this information, you could help them greatly.
Highly descriptive blog, I liked that a lot. Will there
be a part 2?
I just could not leave your web site prior to suggesting that I
actually loved the standard info a person supply in your visitors?
Is gonna be again frequently to investigate cross-check new posts
Somebody essentially lend a hand to make significantly posts
I’d state. This is the first time I frequented your web page and to this point?
I amazed with the analysis you made to create this particular
publish amazing. Fantastic activity!
Great blog you have here.. It’s difficult to find high quality writing like yours these days.
I honestly appreciate people like you! Take care!!
It’s the best time to make some plans for the future and it’s time to be happy.
I’ve read this post and if I could I wish to suggest you few interesting things or tips.
Maybe you can write next articles referring to this article.
I wish to read more things about it!
ᗪefiniteⅼу believе tҺat wҺiϲh you stateԀ.
Your favorite justіfіcation seemed to bbe օn the net the simplest thing to be
aware of. I say to yοu, I certainly get irҝed while pеople think about worries that they plainly doo not know about.
You mаnagᥱd to hit the nail upon the top and also defined out tthe wһߋle thing without having sіde effect , people could take a signal.
Will likelʏ be back to get more. Thanks
Hello my family member! I want to say that this post is amazing, nice written and come with almost all vital infos.
I would like to look more posts like this .
I pay a quick visit each day a few sites and information sites to read articles or reviews, but this
web site presents feature based articles.
Now I am going to do my breakfast, once having my breakfast coming over again to
read additional news.
This is the right blog for everyone who hopes to find out
about this topic. You realize so much its almost hard
to argue with you (not that I actually will need to…HaHa).
You certainly put a fresh spin on a topic that has been written about for many years.
Wonderful stuff, just wonderful!
Hi i am kavin, its my first time to commenting anywhere, when i read this
post i thought i could also create comment due to this sensible piece of writing.
I do not know whether it’s just me or if everybody else encountering issues with your blog.
It appears like some of the text within your posts are running off
the screen. Can somebody else please provide feedback and let me know if this is happening
to them too? This could be a problem with my web browser because I’ve had this happen before.
Thank you
Its such as you learn my thoughts! You seem to grasp so much approximately this, such as you wrote the
ebook in it or something. I feel that you can do with some percent to force the message house a bit, however other than that, this is fantastic blog.
An excellent read. I’ll definitely be back.
I believe that is among the most important information for me.
And i am happy studying your article. But want to observation on few normal things, The website taste is ideal, the articles is in reality nice :
D. Just right activity, cheers
It’s awesome to visit this web page and reading the views of all mates on the topic of this paragraph,
while I am also zealous of getting experience.