Thyroid and Parathyroid Related Testing

 

Thyroid Related Testing:

A review of Thyroid Function Tests can be found here.

TPO, TgAb, TSI, TrAb, TBII:    These are are the anti-thyroid antibodies, as described throughout this website.   In my opinion, for “thyroid testing” purposes, these are the tests I would run first before any of the others to rule out AITD, for the reasons described here.   If anti-Na/I antibody testing ever becomes clinically available, it would be interesting to run these as well.   Be aware that in order to compare values over time, the same lab must be used for measurement of these antibodies.   Autoimmune thyroid disease is one of the most common causes of thyroid conditions in general, and thyroid disorders are being diagnosed in epidemic numbers.   So in my opinion, no thyroid testing is complete without testing for these antibodies.

TSH, fT4, fT3:   Free T4 (fT4) and Free T3 (fT3) represent the amount of “free”, unbound thyroid hormone (hormone not bound to proteins) circulating in the blood and available for use by cells.   Be aware of the things that influence these values, in particular, TSH and fT3, as described here.    If you are on T3 medication, be aware of how serum T3 and TSH values can vary depending on the timing of your last medication dose in relationship to the timing of the blood draw.

TT4, TT3,TBG:   Total T4 (T4) and Total T3 (T3) represent the hormones “bound” to proteins while circulating in the bloodstream.   Thyroid Binding Globulin (TBG) is one of these proteins.   Albumin is another of these proteins, and you will get this value on your basic Comprehensive Metabolic Panel (CMP).   These bound hormone levels provide one form of homeostasis for these hormones.   Note that serum albumin binds cations such as Ca, Mg, Zn, Cu, Na, and K, fatty acids, hormones, Vitamin D and its metabolites, bilirubin, pharmaceuticals, and more.  Testing these at the same time (ie, same draw) as the frees may (or may not) provide clues as to if the binding proteins are playing any sort of role in thyroid-related flox reactions.   In hindsight, I wish I had run these tests much more often than I did to get a feel for how these values were changing with my TSH, frees, and Ab’s.   Of course, I really wish I had run these along with all the other thyroid-related tests during the acute phase of my reaction.   If a pattern of differences occurs between the free and bound values during the acute phase, this may provide a clue as to where the FQ’s are exerting their effects.   However, I would say these tests are for the more motivated patients, and are not the ones I would prioritize unless you’re curious and interested in your own “research” and willing to spend the money.

TG and ESR:   Thyroglobulin and Erythrocyte Sedimentation Rate (ESR).   Test during the acute phase of a flox reaction or any time symptoms of Subacute Thyroiditis are suspected, as described here and here.   Be aware that TG levels can be elevated in cases of both Grave’s and Hashi’s, and are also used as a biomarker for certain kinds of thyroid cancer.   So if TG levels are high, learn all you can with your physician about how to distinguish a benign SAT or Grave’s/Hashi’s from thyroid cancer.   Thyroid cancer is usually not an emergency, and in fact is somewhat of a controversial diagnosis lately (Google “Thyroid Epidemic” to see why).   So know that you have time on your side to research, learn, monitor, and ultimately decide what to do.

Iodine, urine spot test:    This is a relatively inexpensive and simple test that can be run at home, see here.   It would be very interesting to see what’s happening with iodine during the acute phase of floxing.   Understand how diet will affect this value; add up all the potential iodine from your diet before testing.    Don’t start supplementing with iodine before testing if you’re trying to get a baseline.

Fluoride:    For those in the acute phase, this might be an interesting parameter to measure and monitor.

Other Divalent/Trivalent Cations: Ca, Mg, Fe and ferritin, Cu, Zn, Mn, Se and more:     FQ’s are known to bind divalent and trivalent cations.    A common hypothesis is that some of these might be “bound up” in our cells or blood, making them unavailable for use in enzymatic reactions, or excreted with the FQ, thereby contributing to floxing symptoms.   Hypocalcemia, especially in the face of hypomagnesemia, can lead to elevated PTH, and is associated with tendon ruptures (as evidenced by chronic renal failure patients with secondary hyperparathyroidism and tendon rupture).   Selenium is necessary for both thyroidal and extrathyroidal functions, including the deiodinases, along with a wide variety of other functions.     Low copper can contribute to a wide variety of neurological symptoms, along with low WBC’s and other hematological abnormalities.   Iron and zinc are needed for many enzymes to function normally.   Magnesium, of course, is utilized in over 300 enzymatic reactions, with the “tyrosine-magnesium” combination being an important potential target of FQ’s.   Excess or deficient levels of any of these could affect a tremendous amount of biochemical reactions in the body, resulting in a wide variety of symptoms.   It would be interesting to test and monitor these during the acute phase of floxing.   Serum concentration is not equivalent to cellular concentration, but, as with everything else, it’s the best we’ve got to go on right now.   Selenium, Zinc, Copper, Iron (and Ferritin), and Magnesium (serum/RBC) are the ones that come to mind for me.   I tested and monitored for all of these, but didn’t start until 16 months post flox because I didn’t know I could test for these on my own (although my serum Mg was normal per an ER visit during the acute phase).   Chromium, Manganese, and Molybdenum are additional trace minerals to consider; Iodine and Fluoride have already been covered.   If any of these values are low (or Flouride high) during the acute phase, it might be interesting to attempt to compare with a hair sample, which would presumably test pre-flox levels.   There appears to be controversy about how reliable hair analysis is, but it’s something to consider.

Vitamin D and A:    Receptors for Vitamin D and retinoic acid, a metabolite of Vitamin A, are interrelated with thyroid and steroid hormone receptors.    Vitamin D, considered another hormone, is often low in flox victims, and Vitamin A is important for eye integrity (and many flox victims experience eye dryness, blurry vision, “disorientation”, etc).    Vitamin D is also important in parathyroid gland function and calcium/magnesium homeostasis.   As to how serum levels of Vitamin A and D play into all this, I can’t say.   But testing during the acute phase might be a good idea.

 

Parathyroid Related Testing:

The parathyroid glands have different functions entirely than the thyroid gland, with the major functions being to regulate calcium, phosphate, and magnesium homeostasis.    There are four tiny parathyroid glands located essentially on the thyroid gland (embedded somewhat in the tissue).    Presumably, if thyroid gland tissue is being destroyed by autoimmune processes, or is experiencing heavy inflammation, this could affect the parathyroid glands too.    Adenomas could contribute to increased PTH.   Spontaneous tendon rupture can occur due to increased parathyroid hormone secondary to low calcium and magnesium, or due to a PT adenoma.    I was hit hard during the acute phase with severe systemic tendon pain, and I wish I had known to run these tests then, even though my total calcium levels were normal.   I think anyone who experiences any tendon ruptures should run these tests as well.    Hyper and hypo calcemia can result in numerous neurological and CNS symptoms also.    An excellent source of information for all things parathyroid can be found at “Parathyroid.com”.

Ionized Calcium and PTH:   This tests for “free” (unbound) calcium levels and parathyroid hormone levels.

PTH Antibody:    Useful in autoimmune disorders involving parathyroid gland resulting in the production of anti-PTH and hypo-parathyroidism.

Total Calcium:    Run this at the same time as running the ioCa/PTH by running a CMP (comprehensive metabolic panel).   CMP’s are usually very inexpensive if you run them yourself (I can get one for $15.00 in my town).

Vitamin D:    As above. Vitamin D is responsible for enhancing intestinal absorption of calcium, iron, magnesium, phosphate and zinc, and plays a significant role in calcium homeostasis and metabolism via the parathyroid glands.

 

Once you’ve run the Ca/PT test and have the results, you can use this handy chart here at Parathyroid.com to help you determine if a PT adenoma is a possibility.   Scroll down to the chart under “Who has Hyperparathyroidism?” to see where you best fit.

Also at Parathyroid.com, scroll down a couple paragraphs to see on the original page (which I have copied and pasted from that page):   For Canadians and Europeans,  “Your calcium levels are reported in mmole/L, not mg/dl like the US. To convert:   calcium level in mg/dl x 0.2495 = mmol/L. To convert the other way around:   Calcium in mmole/L divided by 0.2495 = mg/dl.  Thus, a calcium level of 11.0 mg/dl = 2.75 mmole/L.”

As with thyroid values, a handy way for everyone to compare values no matter where you live, and to help you get a feel for where your results are within the normal range, is to convert your result to a percentage, as I describe here: “Comparing Your Own Lab Results Across Different Labs Or To Other Patients: Convert Your Numbers To A Percentage”.  Example:

US Values (from serum)(my last test results):

  • Calcium total = 9.7 (8.6-10.4 mg/dL) = 61%
  • Ionized Calcium = 5.3 (4.8-5.6 mg/dL) = 62.5%
  • PTH = 26 (14-64 pg/mL) = 24%

Canadian/European Values (from serum) (taken from a case report):

  • Calcium( total?) = 2.38 (2.25-2.55 mmol/L) = 43%
  • PTH = 2.9 (1.5-6.5 pmol/L) = 28%

 

Note the different units, and different “normal ranges”, depending on the country you are in and which lab ran the tests.   This is why it’s always important to note the “normal value range” whenever you post your results to someone else.   Also note that by changing your result to a percentage, it doesn’t matter what country you are in or which lab ran the tests, you can easily compare your results to others and get a feel for where you’re both at in the range.

I think the PT.com site does a pretty good job of taking a complex subject and trying to make it easier for the average person to understand.  Despite this, I realize it will be a tough go for many people.  If nothing else, know that you can 1) run the tests on your own if you’re in a US state that allows testing, and 2) you can compare your results to the PT.com chart, or convert to percentages, and get a good feel for where you’re at on the spectrum.   As always, if you have any questions about your results, consult your physician or naturopath to have your questions answered.

 

Additional reading for medical professionals or those who are interested:

Normocalcemic primary hyperparathyroidism.   (My note:  an interesting paper of recognition of perhaps a new form of hyperPT. This may be relevant for flox victims, as it is the elevated PTH (not calcium levels) that is suspected in causing tendon ruptures secondary to bone breakdown at tendon insertion sites.   I also wonder if this might be a consideration in the tooth decay and loss that some flox victims experience as well).

Primary Hyperparathyroidism

Please note that PT disorders are diverse and include primary, secondary, and tertiary hyperparathyroidism, as well as hypoparathyroidism and pseudohypoparathyroidism.  The PT.com site focuses specifically on primary hyperparathyroidism because this is a condition that has a good surgical cure success rate.

 

 

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