Health Research (thyroid hormone focus)

Taking part of one's thryoid meds at night is something many have been doing. (with docs OK)

As well many folks experiences of improved wellbeing, and for some, just plain convenience of not having to worry about what they eat in the morning or rushing to work etc., here's why from this post

There is a diurnal cycle of TSH secretion from the anterior pituitary. In humans, peak TSH concentration occurs in the night and the nadir in the late afternoon (Fisher, 1996). Diurnal cycles have been reported for thyroid hormone levels in rats Cokelaere et al., 1996 ), amphibians (Gancedo et al., 1997) ...

It is normal to have some thyroid hormone released at night, so taking some at night makes sense.(apologies to comparing humans to rats and amphibians but common things do seem to occur amongst animals especially between rats and humans which are surprisingly fairly close mammals as far as the way our bodies work!)
Cokelaere-Influence of feeding pattern on thyroid hormones in long-term food-restricted rats
http://www.thieme-connect.de/ejournals/abstract/hmr/doi/10.1055/s-2007-979802  at Uni of Syd Medical library 574.192705 2

Here's some of the old posts from 2003-2005 on taking at least part of thryoid meds at night, some took Armour (THYROID + T4+t3), some took just T4, some took a combo.
Shows that thyroid med consumers have found the benefit of at least some thyroid hormones at night time for a long time, presumably way before this:-)

http://forums.about.com/n/pfx/forum.aspx?tsn=1&nav=messages&webtag=ab-thyroid&tid=46477
I have found that taking Cytomel at night helped me get restful good sleep. My daughter takes Armour at night also and it helps her sleep better.
What is your story?!!! CoachLinda

http://forums.about.com/n/pfx/forum.aspx?tsn=2&nav=messages&webtag=ab-thyroid&tid=46477
Hi, Linda!
Taking my third dose of Armour in the evening between 7 and 10pm helps me sleep better because it appears to prevent the breathing problems that I had previously.
endophobia!

http://forums.about.com/n/pfx/forum.aspx?webtag=ab-thyroid&nav=messages&msg=46477.6
me too endo. I need 15mg Armour equivalent (1/4 g)at night...slow released. Definitely aids sleep, and keeps me a tad warmer during the night. Also I don't feel quite so dead in the morning, so it is easier to get up.
Jan
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http://forums.about.com/n/pfx/forum.aspx?tsn=36&nav=messages&webtag=ab-thyroid&tid=67042  Choccy with thryoid meds at night for better absorption, or at least it sure sounds like a great excuse with some originality!

Ok, I gotcha per taking T4 at nite with chocolate. (Dumb me for not figuring out what you were saying). For the 1st time in my life, I'm not constantly cold. Aren't cold legs, feet & hands the pits? Once my T3 got out of the gutter, warmth followed. Now, I get hot & still am unable to sweat. Maybe adding tyrosine helped, since I began taking it about the same time that T3 inched up. Believe me, I'm not complaining about being warm. It's wonderful to not search out clothing with long sleeves.

Accepted on March 17, 2008 FREE FULL PDF
Free triiodothyronine has a distinct circadian rhythm that is delayed but parallels thyrotropin levels
W. Russell, R. F. Harrison, N. Smith, K. Darzy, S. Shalet, A. P. Weetman, and R. J. Ross*
Academic Unit of Diabetes, Endocrinology & Metabolism, and Department of Automatic Control & Systems Engineering, The University of Sheffield, Sheffield S1 3JD, UK; Chemical Pathology, Royal Hallamshire Hospital, Sheffield S10 2JF, UK; Department of Endocrinology, Christie Hospital, Manchester M20 4BX, United Kingdom

* To whom correspondence should be addressed. E-mail: r.j.ross@sheffield.ac.uk.
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Context: TSH is known to have a circadian rhythm but the relationship between this and any rhythm in T4 and T3 has not been clearly demonstrated.

Objective: With a view to optimising thyroid hormone replacement therapy we have used modern assays for FT4 and FT3 to investigate circadian rhythmicity.

Setting: University Hospital.

Design and subjects: Cross sectional study in 33 healthy individuals with 24 hour blood sampling (TSH in 33 and FT4 and FT3 in 29 individuals) and cosinor analysis.

Results: 100% of individuals showed a sinusoidal signal in TSH, for FT4 76% and for FT3 86% (p<0.05). For FT4 and FT3 the amplitude was low. For TSH the acrophase occurred at a clock time of 0240 h and for FT3 approximately 90 minutes later at 0404h. The group cosinor model predicts that TSH hormone levels remain above the mesor between 2020 h and 0820 h and for FT3 from 2200 h to 1000 h. Cross correlation of FT3 with TSH showed that the peak correlation occurred with a delay of 0.5–2.5 hours. When time adjusted profiles of TSH and FT3 were compared there was a strong correlation between FT3 and TSH levels (=0.80, p<0.0001). In contrast, cross correlation revealed no temporal relationship between FT4 and TSH.

Conclusion: FT3 shows a circadian rhythm with a periodicity that lags behind TSH suggesting the periodic rhythm of FT3 is due to the proportion of T3 derived from the thyroid. Optimising thyroid hormone replacement may need to take these rhythms into account.
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I have been taking a part of my thyroid meds at night since 2002, and try to include some T3 with the T4 taken at night(about a human ratio of T4:T3 but that is very approximate!)
A few of us on a thryoid forum started before 2003- here's some of the old posts
My thoughts and practise are in this post from Apr 07 & this post below
AS I also take estradiol this post is on the benefits of at taking part of one's meds to approximate any natural circadian rhythm that occurs , with both thyroid meds and oestradiol :-)
In practise since 2002, I have always taken somewhere between 1/4 Grain THYROID(Armour equiv) and one half of my thyroid meds at night, but others have taken them all at night. I feel I need to spread mine to last better(some also before large meals for digestion and before a lot of exercise), but maybe one day I also will be able to take them all at night!