Hi! I’m new here. I have been struggling with my endo for a diagnosis. About a year ago I had many blood draws where my TSH was very low, my T4 was low and my T3 was normal. I was not medicated. My doctor did not know how to treat me, but I was very hypo symptomatic. After some time my TSH regulated but he would not test my T3/T4. He referred me to an endo and I received my results today.
TSH .99 (.35-5.0)
T3 Free 3.9 (2.6-5.7)
T4 Free 9.2 (9.0-19.0)
I’m including my insulin and c-peptide results I’m not sure they are relevant.
C-peptide 249.0pmol (298-1324)
Insulin 33.8pmol (43-194)
Thank you for the information.
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Bubbledup
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I would expect a much higher TSH with your low fT4, in this case you would then be diagnosed as hypothyroid.
Strict dieting can reduce TSH and thyroid hormone levels. I know nothing about insulin but is it possible your low insulin levels are causing malnutrition? If this is the case and it could be corrected your TSH might pick up and stimulate your thyroid to produce more hormone.
It looks like your TSH is too low rather than any problem with your thyroid.
Thank you for the information. I am not currently dieting, I would say currently my diet is not as clean and strict as it typically is. I will clean up my nutrition again, I won’t diet strictly and I will see if there are any improvements to my symptoms.
Just to clarify I wondered if the low insulin was having the same effect as being on a diet - reducing your available calories. I have to little knowledge of insulin so just raising the possibility.
Ahh yes! That is a good question. I will dig deeper. It’s a good hypothesis. I don’t know much about insulin either. I had been trying to research about thyroid issues, and the insulin results popped up in one of my blood draws. My endo requested it. She’s very hard to get any diagnosis from, or any information either.
For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested. Also EXTREMELY important to test vitamin D, folate, ferritin and B12
Low vitamin levels are extremely common, especially if you have autoimmune thyroid disease (Hashimoto's) diagnosed by raised Thyroid antibodies
Ask GP to test vitamin levels and thyroid antibodies
Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .
This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)
Is this how you do your tests?
If in the uk
Private tests are available as NHS currently rarely tests Ft3 or thyroid antibodies or all relevant vitamins
“According to the current TSH reference interval, hypothyroidism was not diagnosed in about 50% of the cases in the afternoon.”
“Further analysis demonstrated inadequate compensation of hypothyroidism, which was defined in 45.5% of the morning samples and in 9% of the afternoon samples”
TSH levels showed a statistically significant decline postprandially in comparison to fasting values. This may have clinical implications in the diagnosis and management of hypothyroidism, especially SCH.
With low c peptide and insulin you seriously need to also check your blood sugar levels. These could indicate type1 diabetes which is auto immune so you also need antibodies tested. With a low TSH in these circumstances you also need your cortisol checking by saliva testing. If you have any auto immune issue this could show low cortisol or even leaning to Addison's as all these are connected. Your thyroid is possibly fine. It's just reacting to what else is going on in your body. The thyroid could be being slowed down by the adrenals because ultimately it's cortisol that balances the release of glucose. The body will do what it can to maintain balance.
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