Am I hypothyroid?

[mhhk]

Dear all, I'm 26 year old healthy male and currently not under thyroid hormone treatment. I would like to ask your opinion about my blood test results:

1st test on April 12, 2017
TSH: 0.66 uIU/mL (lab range: 0.3-5.10)
FT4: 12.9 pmol/L (lab range: 11.5-22.7)
FT3: 5.6 pmol/L (lab range: 3.5-6.5)

2nd test on July 6, 2017 (same lab as 1st test)
TSH: 0.66 uIU/mL (lab range: 0.3-5.10)
FT4: 12.5 pmol/L (lab range: 11.5-22.7)
FT3: 5.5 pmol/L (lab range: 3.5-6.5)

3rd test on July 20, 2017 (different lab, now I went to endo)
TSH: 0.66 uIU/mL (lab range: 0.35-4.55)
FT4: 11.9 pmol/L (lab range: 11.5-22.7)
FT3: 5.1 pmol/L (lab range: 3.5-6.0)

Why I have very low FT4 with normal FT3? However I notice both my FT4 and FT3 are declining but my TSH remain the same.

My other hormones, LH, FSH, HGH, cortisol, prolactin, estradiol are normal. But my total Testosterone is in the middle range and my free Testosterone almost hit the low border. Can it be due to hypothyroidsm?

I have constipation for years, started to feel very tired since last year and last week started to have sleep apnea (whenever I would fall asleep, I felt my breathing stopped). I loss weight and muscle. Feeling cold sometimes, have high cholestrol, frequent urination and blurred vision. Whenever I'm working in my office, I feel very anxious which I believe due to my low Test. Last night I took my first basal temp, it was 36.1C.

My endo said my thyroid is within the range and normal. I have another appointment with him next week and want to ask his opinion about my Testosterone level (I did the test in another lab) and would like him to test my RT3, TPO, DHEA and SHBG. Appreciate your kind opinion.Thank you.

[gimel]

To improve the chances for getting the additional tests, you should emphasize all the symptoms you have and the need to find out what all is causing them.   You might also make use of the following link.  It has a lot of useful info about symptoms being the most important indicator of thyroid status and what tests should be done.  I highly recommend that you read at least the first two pages nad more if you want to get into the discussion and scientific evidence for all that is recommended.

http://www.thyroiduk.org.uk/tuk/TUK_PDFs/diagnosis_and_treatment_of_hypothyroidism_issue_1.pdf

If the doctor resists doing the tests and won't consider a diagnosis of hypothyroidism, then give him a copy and ask him to review and re-consider.  If the doctor will read the paper he will have a hard time refuting the scientific evidence behind all the recommendations.  If he still refuses to consider clinical treatment and at least give you a therapeutic trial of thyroid med adequate to get your FT4 and FT3 to good levels, then you will need to find a good thyroid doctor that will do so.

[gimel]

In assessing a patient for the possibility of hypothyroidism, the most important consideration is symptoms, followed by the biologically active thyroid hormones, Free T4 and Free T3.  You have numerous symptoms that are frequently related to hypothyroidism.  In addition your FT4 is only at about 4% of its range, which is way too low for most people.  I say that because the ranges are far too broad due to the erroneous assumptions used in establishing them.  Your Free T3 is at about 64% of its range, so apparently your body is converting extra T4 to T3 in an effort to maintain thyroid function as best possible.  Many of us have found that FT4 needed to be at least at mid-range, and FT3 in the upper third of its range, and adjusted from there as needed to relieve hypo symptoms.  

Your TSH is relatively low for those FT4/FT3 results, which makes me suspect that it may be central hypothyroidism.  With central hypothyroidism, there is a dysfunction in the hypothalamus/pituitary system resulting in insufficient output of TSH to adequately stimulate the thyroid gland.  There is further evidence of a pituitary problem in a couple of symptoms that may be related to low cortisol.  So it would also be good to test for cortisol.  Your low testosterone may well be related to being hypothyroid.

Since hypothyroid patients are so frequently deficient in Vitamin D, B12 and ferritin, those should be tested and then supplemented as needed to optimize.  D should be at least 50 ng/mL, B12 in the upper end of its range, and ferritin should be at least 100.  If not tested for blood sugar level that would be a good idea also.  For you I am not sure you need RT3 at this time, nor is a TPO ab test indicated.  

The most important thing to keep in mind is that a good thyroid doctor will treat a hypothyroid patient clinically by testing and adjusting Free T4 and Free T3 as needed to relieve symptoms, without being influenced by resultant TSH levels.   Symptom relief should be all important, not  just test results, and especially not TSH levels when taking thyroid med.  

[mhhk]

Hi Gimel, thanks for your comment. I also suspect that there's something wrong with my pituitary because despite my FT4 and FT3 are decreasing, my TSH remain at the same level i.e. 0.66, which I thought that is the max level it can produce. My endo didn't know the results from the first and second test because I did the test from another lab. But when I put the results side by side, I just realise my TSH remain the same.

Also, when I did my third blood test with my endo, my GH is actually slightly above the level, 12.2 mIU/L (lab range <9.0). So I took another test last week to check whether I have something wrong with my pituitary (i don't remember what the name of the test is but I had to drink glucose syrup and had my blood taken every 30 minutes for 2 hours). I will have the result next week. When I checked online, 12.2 is still within the range for other labs. So, I am not sure. I will get other tests like you have suggested. Thanks.