Log in
Thyroid UK
93,474 members107,529 posts

Thyroid hormone level is associated with motor symptoms in de novo Parkinson's disease

So the obvious question, does thyroid hormone supplementation (T4, T3 or in any combination) help those with Parkinson's disease?

J Neurol. 2015 May 19. [Epub ahead of print]

Thyroid hormone level is associated with motor symptoms in de novo Parkinson's disease.

Umehara T1, Matsuno H, Toyoda C, Oka H.

Author information

1Department of Neurology, Daisan Hospital, The Jikei University School of Medicine, 4-11-1 Izumihoncho, Komae-shi, Tokyo, 201-8601, Japan


Sympathetic denervation has been observed not only in the myocardium but also in the thyroid of patients with Parkinson's disease (PD). We investigated whether sympathetic denervation as indicated by decreased cardiac 123I-meta-iodobenzylguanidine uptake is associated with the levels of thyroid hormones and whether the levels of thyroid hormones affect clinical manifestations in patients with PD. The subjects were 75 patients with de novo PD and 20 age-matched healthy controls. We examined the levels of thyroid-stimulating hormone, free triiodothyronine, and free thyroxine, and evaluated the associations of these levels with cardiac 123I-meta-iodobenzylguanidine uptake and motor symptoms. The results showed that the free triiodothyronine level was below the normal range in 29 patients (approximately 40 %) and was significantly lower in the patients with PD than in the controls. The decreased free triiodothyronine level was associated with akinetic-rigid motor subtype and washout ratio of cardiac 123I-meta-iodobenzylguanidine scintigraphy. The free triiodothyronine level negatively correlated with disease severity. Thyroid-stimulating hormone level was within normal range. However, its level was lower in patients with tremor-dominant type or mixed type than in those with akinetic-rigid type. All correlations of these variables with the levels of thyroid hormones remained statistically significant on multiple regression analysis. Our results suggest that the thyroid hormone level, especially the free triiodothyronine level, is closely related to motor symptoms in patients with de novo PD. Further studies are needed to clarify whether the decreased hormone levels have functional roles in motor and non-motor symptoms.



[PubMed - as supplied by publisher]


9 Replies

Very interesting! Is t3 involved in the production of dopamine? I seem to remember my Grandpa taking L-dopa, among other things, which did seem to help for a while.

Depressions seems to be a common symptom in Parkinson's Disease and I don't think it's necessarily due to having to deal with losing control of one's motor function either. As we know, depression is often linked to low T3 levels.

Thanks for posting. Looks like useful research not only for Parkinson's disease but for thyroid disease too.


Sadly, it seems that l-dopa often helps only for a while.

Quite a few papers refer to PD and thyroid - in various ways.

Endocrine. 2001 Aug;15(3):297-303.

Effects of thyroid hormone on the renal dopaminergic system.

Del Compare JA1, Aguirre JA, Ibarra FR, Barontini M, Armando I.

Author information


This study determined the effects of thyroid hormone on the renal dopaminergic system. Surgical thyroidectomy (Tx) and treatment with 2-thiouracil (Thio) decreased renal cortex Na+/K+ ATPase activity and urinary volume. Tx also decreased urinary Na+ and urinary L-DOPA without changing urinary excretion of Dopamine (DA). Thio treatment decreased slightly urinary L-DOPA and Na+, but increased urinary excretion of DA. In both models of thyroid hormone deficiency, the ratio urinary DA/DOPA increased. Changes after Thio treatment were reversed after one month of drug withdrawal. Treatment with T3 via osmotic minipump increased Na+/K+ ATPase activity and urinary L-DOPA, did not change urinary DA, and increased the ratio DA/DOPA. To further analyze the effects of thyroid hormone deficiency, we administered selective DA1 (SCH-23390), DA2 (Sulpiride), and a non selective (Haloperidol) DA receptor antagonists to Thio treated and control animals. The DA1 antagonist decreased diuresis, natriuresis and urinary L-DOPA in control, but had no effect in Thio treated rats. Sulpiride had no effect in either group. The combination of SCH-23390 plus Sulpiride decreased urinary L-DOPA and urinary volume only in Thio treated animals. Haloperidol decreased urinary volume in Thio treated animals, but had no effect in controls. Our findings suggest that renal DA synthesis is to some extent dependent on thyroid hormone levels, and that the response of DA receptors is altered by thyroid hormone deficiency, indicating a role of this hormone in the regulation of the renal dopaminergic system.



[PubMed - indexed for MEDLINE]



We must not forget Awakenings when thinking about l-dopa.



If i was diagnosed with parkinson`s, I wouldn`t bother taking meds because they only work for a short time & have horrible side effects. I`d want to go for deep brain stimulation. I don`t know why more doctors don`t recommend this rather than prescribing medication.


An obvious next question for me, considering that only 40% had low T3, would be : were they mis-diagnosed in the first place because their TSH was 'normal' - which would suggest secondary hypo and pituitary damage and... and... something. I Don't know. But a lot of unanswered questions.

1 like

Hi Helvella, you do put some really interesting posts on here, I try not to miss them, most are way over my head though. :)

My poor Dad, now passed, had a 'triple whammy' as the Neuro specialist coined it,

Parkinson's, Parkinsons Dementia and Supra Nuclear Palsy. I have often wondered if there was a connection and looking back I have wondered what his Thyroid bloods would have read, not forgetting his vitamin B12 and vit D bloods.

Dad became bowed legged, looking back I wish he could have had his vitamin D levels checked, I'm sure he had rickets as he never went outdoors much.

I was found to be Vit D deficient and it affected my legs similarly too, I explained to the Doctor I was walking differently and told Doctor it felt like my legs were bowing, but luckily now on a good dose of Vit D my legs have their spring back in them and are back to normal. :)

Also I have read there is a connection of low thyroid in ADHD, ASD, Asperger's and in having Baby Blues too and probably more.

I also know there is a connection with T3 helping to quieten down ticks and outbursts from sufferers of Tourettes after reading posts between Tourette suferers which I might have mentioned to you before helvella.


Interesting - My mum also had a triple whammy - Hypothyroid, Coeliac and Parkinsons. I really wish I knew what I know now about levels of TSH, vitamins and minerals. I wonder too what her blood levels were. Sadly its too late for her as she passed 5 years ago but I am determined to make sure I have a better quality of life than she had - I am at double whammy - Hypo and newly found out Coeliac

Thank goodness for this Forum and the amazing support from everyone


Sorry to hear about your Mum, judburke and now yourself too.

More medical evidence is coming to light as each year passes and with internet medical forums people are connecting and linking their medical conditions to others far quicker than they could do so before, such amazing things are coming to light.

Many illnesses have now been linked to a lack of vits and minerals or having a low immune system, (low T3)

Maybe sometime in the future Doctors will be routinely checking low thyroid, vits and minerals for many more illnesses.

At least us lucky members on here, TUK, have been quite privileged to read and learn how to keep ourselves and our families healthy. :)

1 like

Thanks Coastwalker! Lets hope all the doctors join our campaign. My doctor didn't know too much about the vit and mineral levels but he has been great at listening to me when I say "Thyroid UK says I should have........levels"

I am determined that I will stay at "Double Whammy" and that I WILL feel well. Its day 6 of my GF journey and already the brain fog is lifting and some of my motivation is returning. I hadn't realised how much of "me" had been hidden for too long.

Thyroid UK and this site and now Coeliac UK and Gluten Free Warriors are inspiring. I have 2 teenage daughters and there is no way that they will go undiagnosed :)

1 like

You may also like...