Stanislovas S. Jankauskas, Marco B. Morelli and Jessica Gambardella contributed equally to this study.
Physiologically, thyroid hormones are able to affect the fundamental determinants of blood pressure (BP): cardiac output, peripheral vascular resistance, and kidney function (Figure 1). The thyroid-mediated fine orchestration of cardiac contractility, vascular tone, and renal homeostasis confers to the thyroid gland a key role in the pathophysiology of hypertension. Indeed, BP is altered across the entire spectrum of thyroid diseases.1However, the effects of thyroid disorders on BP are very intricate, mirroring the multifactorial and disparate actions of thyroid hormones on cardiovascular system and metabolism. In fact, if on one hand thyroid hormones increase contractility, tachycardia, and basal metabolic rate, which are positive regulators of BP, on the other hand they are able to decrease systemic vascular resistance, thereby lowering BP. Ergo, the balance between these opposite actions is eventually able to achieve an optimal regulation of BP, and modifications in thyroid hormones availability, both hypo- and hyperthyroidism, can alter this fine equilibrium. A wide and consistent literature is available on the association between thyroid disorders and hypertension.2However, only few studies have explored the relationship between BP and thyroid hormones in healthy subjects, in order to understand whether different levels of thyroid hormones, within a physiological range, can reflect changes in BP. In this context, in the current issue of the Journal, Jamal and colleagues offer their elegant investigation conducted on 691 healthy subjects.3The authors elegantly show that in a physiological context, augmented serum levels of triiodothyronine (T3) and thyroxine (T4) are associated with an increase of both peripheral and central BP. A strength of the study is denoted by the choice to measure central BP, which is suggested to be a more reliable prognostic marker in cardiovascular disorder compared to conventional brachial cuff BP.4The authors open the scenario for a potential role of serum level of thyroid hormones as predictor of central BP, and therefore a powerful prognostic factor of hypertension and cardiovascular complications. Of course, further studies are needed to verify and better understand the proposed relationship, even to enlarge the sample population. Moreover, in future studies it could be interesting to perform a time-course assessment of thyroid hormones levels (which usually oscillate in the same subject) evaluating their effects on BP variation. Indeed, a circadian rhythm has been demonstrated for triiodothyronine (T3), with a periodicity that lags behind thyroid-stimulating hormone (TSH).5, 6Another aspect that needs to be further examined is the potential role of the effects of T3 and T4 on the intricate interaction between cardiovascular and renal systems.7-9To better characterize the complex context in which the study performed by Jamal and colleagues3fits, here we propose a summary of the central mechanisms by which thyroid hormones can affect cardiac output, vascular resistances, and kidney function. We also summarize the results of the most recent clinical studies focused on the relationship between thyroid hormones and hypertension.
My ongoing rant is, why are medics so reluctant to carry out thyroid tests in order to eliminate (or establish) the possibility that the thyroid gland, a major organ in the body, might just hold the clue to a patient's ill health?
My BP dropped when I became adequately medicated with T3-only!
I agree, but I feel that somewhere out there an enlightened medic/ scientist must, after over a hundred years and more of thyroid treatment have the nous to join up the dots and realise the impact that the thyroid gland has on general health....and act on that.They seem to have closed their minds and eyes.
To take an example, had scientists not engaged in blue sky thinking which they translated into practical change we would not now have Covid booster vaccinations or malaria vaccinations.
It's easy to say, so-and- so won't work, the success comes from trying harder!
TSH alone clearly won't help...but add in FT4 and FT3 and a picture emerges.
I guess countless people are suffering quietly behind closed doors because they are suffering from wrongly diagnosed or undermedicated thyroid disease, and the many illnesses that this can cause.
It took me over 50 years to get to the bottom of a life time of different " ailments" that despite scopes, scans, medications, physical theraphy ( both NHS and private) medics could neither adequately explain nor effectively treat....syndromes ME,CFS, IBS, bladder problems and the like were diagnosed but they are not diseases only a collection of symptoms.
I was one of these patients suffering behind "closed doors" and my life was in danger!
I reached the point where I struggled to function. Some of these symptoms could be eased with various treatments but nothing came close to treating the root problem...
until I arrived here! Thank you TUK!
I eventually discovered that I need a supraphysiological dose T3 to overcome a type of thyroid hormone resistance that caused low cellular T3....or cellular/tissue hypothyroidism rather than glandular hypothyroidism.
The passing decades, it seems, have caused some lasting damage but so much has improved now. I self medicate. The only endo I saw was adamant that I did not need T3 and would have had me continue taking levothyroxine which I was not tolerating!
Anyway, apologies helvella, I'm ranting again but nothing will convince me that until the wider significance of the thyroid gland's functions is understood and accepted that anything will change.
Maybe, just maybe, this paper throws a chink of light into a very dark space.....and hopefully medics will listen to the scientists
So many papers which discuss thyroid hormone usage, other than obvious hypothyroidism, come from areas like cardiac, or kidney, or whatever. And not from the endocrinologists we might have expected.
Thanks for posting helvella. At last some sensible research on the topic. Personally , I know from my patient record that since taking T3 my kidney function has greatly improved and my heat rate increased from average 58 beats to 63. I suffer from white coat syndrome with regards to my BP so I must monitor at home, haven't done for a while but would be good to see how things are!I wonder when the medics will properly understand that good thyroid hormone levels are important to optimal functioning of all the systems in our bodies?
Helvella Thank You for this Great Post. Many of us that are already benefiting from thyroid meds are very aware how life saving thyroid meds are. For those that have not been properly diagnosed or missed diagnosed are being put on different meds . Blood pressure pills , sleeping pills , cholesterol pills, upper/downers and everything else instead of trying some thyroid dose. Personally I feel that anyone over the age of 60-ish should be on some low dose thyroid meds.Thank you for bringing a great important/valuable topic to the forum.
Thank you for your post, this sounds like me. I have high thyroglobulin antibodies, hypertension low vitamin D and a thyroid nodule.The doctor says watch and wait, and all the time my blood pressure is going through the roof .
Dx amlodipine and ramipril but no thyroid medication.
Strength and Sympathy. If you feel that you have exhausted all your avenues. I say go for it. There is no point to get sick over Dr's negligence. You know what you feel and how you feel and what it's doing to you. You might not much of a choice . I hope you find a Dr that listens to you thinks out of a "Box" and does not go by lab numbers sole.
I hope you find "Optimal" very soon. You Deserve It.
It's so very interesting what your saying humanbean. I found very similar experiences. On higher T4 I was having palpitations anxiety, fatigue, high BP.Only when I lowered my T4 dose with a small dose of T3 my symptoms improved. Especially the palpitations BP was lowered etc.
On NDT I did not feel as well. It's possible that my body recognized it as thyroid and it was attacking it. I have Hashimito. Lucky me. T3 works well only if I have high enough T4 for it. Interesting but true. With lower T4 and additional T3 I experience muscle/joint pain ,lethargy , I feel T3 run out and get surges. I can not sleep and experience brain foggyness.
Listen to your body it communicates so well. It won't let you down.
Nutrients are so very important too. It helps our thyroid meds work better for us.
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