Huge variance in thyroid test results in 1 year

[Cinnamon16]

Hi all,

Last year (May, to be precise), I visited an endo to get my thyroid tested, based on symptoms I’ve experienced for many, many years (severe brain fog/poor working memory, anxiety, lethargy, stomach weight I can’t lose despite eating clean/healthy and exercising frequently, etc). Worth noting: I did *not* suffer from dry skin, cold-sensitivity, or constipation. The test results came back normal.

Last month, I went back for another blood test (with a different doctor), and this time, my results were significantly different, and indicated hypothyroid. The only differences between the two tests that I can muster are
1.) I was fasting for this second one, and
2.) I had been sleeping poorly in the nights leading up to it.

Below is a link to a screenshot of the difference between the two dates. Note especially the change in TSH (1.05 vs. 4.31) and TPO Ab (0.5 vs. 9). The rest remain similar.

http://i.imgur.com/cHgVotk.png

Also worth noting: The two times prior to this my TSH was tested (March 2014 and June 2013), my TSH levels were 1.3 and 2.1, respectively.

What might be the cause of this variance? Should I begin thyroid medication, or might another variable be to blame for my high TSH/high TPO Ab?

(A recap of my symptoms: severe brain fog/poor working memory, anxiety, lethargy, stomach weight I can’t lose despite eating clean/healthy and exercising frequently

I do *not* suffer from dry skin, cold sensitivity, or constipation)

[des900]

changing dose based on tsh result alone is the big mistake what most doctors continuing to do so.

tsh is just one variable but not whole.

in my view first check free t4 then tsh. if tsh is high and free t4 is also high never raise the dose and instead lower the dose.

increase t4 dose only if free t4 is lower than optimal range. also no need to look at tsh too in such case.

[Red_Star]

The August 2012 study entitled "Clinical Significance of TSH Circadian Variability in Patients with Hypothyroidism" (Sviridonova MA, et. al) showed an average morning TSH level in the subclinically hypothyroid group was 5.83 mU/L and in the afternoon was 3.79 mU/L; 73% TSH circadian variability.  

The average morning TSH level in the hypothyroid group taking levothyroxine was 3.27 mU/L and in the afternoon was 2.18 mU/L; 64.7% TSH circadian variability.  Morning: 8 - 9 am. Afternoon: 2 - 4pm.

***

And an article that lists 15 other reasons...

About Guide - Reasons Why Your TSH May Be Fluctuating...

"Change in Dosage -- changing your thyroid medication may change your TSH.
Potency Fluctuations in your medication
Lab changes or mix-ups
The timing of when you take your pill
Starting or stopping a high-fiber diet
Starting/stopping calcium or iron supplements
Eating too many soy products
Eating too many goitrogenic foods, which include Brussels sprouts, rutabaga, turnips, kohlrabi, radishes, cauliflower, African cassava, millet, babassu (a palm-tree coconut fruit popular in Brazil and Africa) cabbage, and kale
Change of seasons -- TSH can rise in the colder months
Hormonal fluctuations
Pregnancy
Certain herbs/Supplements
Certain prescription drugs
Stress or illness
Progression of your thyroid disease."

[Cinnamon16]

Thanks for your response!

Both the Mayo Clinic and my lab say that a TPO Ab level of 9 or above is considered "high," and mine was a 9 exactly. The test was drawn in the morning, about 60-80 minutes after I woke up.

[goolarra]

Fasting is not an issue with thyroid tests.  However, time of day the blood was drawn is.  TSH can vary as much as 70% diurnally, and FT3 and FT4 have their circadian rhythms as well.

Since your antibodies are elevated (what's the reference range on your TPOab?), the variance could very well be explained by continuing loss of thyroid function.  It's not unusual to swing back and forth in the early stages of Hashi's.  

TSH, a pituitary hormone, is a very indirect measure of thyroid status.  Other variables could definitely be involved.  Antibody levels also swing wildly intra-day.  However, FT3 and FT4 are direct measures, and your FT4 has actually gone up, though it's still only 29% of range, low of the 50% guideline.  FT3 does look good.

I'd still like to know the reference range on your TPOab to see how elevated it is.  

[des900]

based on your result you can either wait or start a small levo dose of 12.5 mcg to make that free t4 bring in optimal range.

since your free t3 is in optimal range taking levo at morning before breakfast is best.

[Cinnamon16]

The lab range for FT4 was 0.9 - 1.8, with my doctor indicating that 1.3 - 1.6 was the best/optimal range. She indicated that my T4 was slightly low.



The lab range for FT3 was 2.5 - 4.4, with my doctor indicating an optimal range of 3.2 - 3.6. She said my FT3 level was "gorgeous."


Lab ranges are fairly useless, btw; they're the average of all people tested there, including the elderly, infrimed, etc. This results in the "normal" testosterone range being 300-100, and the "normal" TSH range being 0.5 - 5.0--both of which are insane! It's actually much wiser to do research, and instead go by what professionals consider to be the "optimal" for your age and health. :)

[des900]

you didn't mentioned the lab reference range especially for free t4 and free t3

tsh no need to look as it doesn't tell anything regarding how thyroid working instead look for free t4 value and free t3 values.

anyway from your result it looks like hashimoto thyroiditis in which seeing variation in tsh is quite normal.

[Cinnamon16]

I should've added: I'm a 25-year-old man.