Sunday, June 22, 2008

A new path

The thyroid is an endocrine gland located in the neck. For a gland, it’s a good size—and it ought to be! The hormones produced by the thyroid affect every cell and system in the body. If the thyroid hormones are out of whack, it can impact one’s heart rate and pulse, metabolism, energy level, temperature, experience of pain, cholesterol levels, eyesight, and even skin and hair health.

The most common test run when a thyroid problem is suspected is a blood test to determine one’s TSH (thyroid stimulating hormone) levels. TSH is released by the pituitary gland to tell the thyroid when it needs to produce more T3 and T4, the two thyroid hormones. Generally speaking, a high TSH level indicates that the usual feedback loop is not resulting in enough thyroid hormone, so the pituitary gland keeps upping production in an attempt to get the amount it wants. But if the thyroid is underperforming or failing, it simply cannot keep up. (Things can also go the other way, where the thyroid pumps out too much, regardless of what the pituitary says.)

I have a decent amount of second-hand information on thyroid problems; Trillian has a history of them and is currently on a common medication to regulate her levels. She had to fight hard to get a doctor to pay attention to her complaints, all definite symptoms of hypothyroidism, because at the time the reference range for TSH went up to 5.5 or 6. Most labs, including the one I use, have moved the high end of the range to 4.5 or so, but many people (Trillian included) feel that anything over 3.0 in a woman is suspect and that most women are probably at optimum when their TSH is at 1.5.

The TSH test I had in March came back at 2.52. Well within the reference range for my lab, so my physician included it in her observation that all of my levels were fine. She had also ordered tests to look for a number of thyroid antibodies. If those had been detected, it would have indicated an issue to pursue, regardless of my TSH level. But that was clean too.

Trillian gave me her take on those numbers, that I was close enough to 3.0 that I should keep an eye on things. She also inspired me to dig through some old medical records and see what my TSH has been in the past. I discovered an interesting pattern. The oldest level I had on record, from before I was even trying to get pregnant with Scooter, was right around 2.5. But the blood tests from during my pregnancy and soon after were more like 1.8. Interesting, something to bring up with my physician, but not necessarily a problem.

Then Cid (Clueless* Infertility Doctor) made some offhand remark at the beginning of my appointment about my TSH being “borderline.” Turns out he’s another proponent of moving the reference range down to 3.0. He didn’t dwell on it, but one of the tests he ordered for me, in addition to another TSH, was an assay of my free T4. Turns out he did something right. I would guess that he expected my T4 to come back low, which would indicate hypothyroidism.

Funny thing though. My free T4 came back high. Not super high, but outside the reference range.

I sifted through a lot of online sites and charts about thyroid test results. My particular situation—high T4, normal/high-normal TSH—just did not appear in most places I looked. But finally I came up with something that not only fit my test results, but also a whole host of other health complaints I’ve had: resistance to thyroid hormone (RTH).

In the past, I’ve often thought I might have hypothyroidism. I am overweight, and despite recently upping the frequency and intensity of my exercise, I cannot lose weight. I am always tired, my nails have always been brittle, I ache all over. Trillian would probably throw in depression and irritability. But then I don’t have some of the hallmark symptoms, things that result from metabolic changes, particularly cold intolerance. If anything, I have a tendency to overheat easily and much prefer the cold. (Though not the incessant Toronto winter.)

Turns out that people with RTH can have symptoms of both hypo- and hyperthyroidism. But the thing that just about knocked me out of my chair was when I came to a section in the Wikipedia article about RTH as a possible/likely cause of fibromyalgia. See, I was diagnosed (tentatively, reluctantly by a neurologist) with fibromyalgia a bit before Scooter’s first birthday. Because I am unwilling to take sleep aids or muscle relaxants on a regular basis, I have managed it primarily through diet and exercise. And otherwise pushed through the aches and poor sleep, as I have been since they became part of my baseline around the time puberty hit.

And then I started finding the information I had been looking for: women with untreated RTH are much more likely to suffer miscarriages. In particular, the chance of a miscarriage rises exponentially if the fetus is not also affected by RTH. I’ve also seen anecdotal suggestions that some women with RTH find their usual symptoms alleviated by pregnancy (when the fetus also has RTH).** But the good news is that there appears to be a good chance of a successful pregnancy and healthy baby when the mother is treated with T3.

So I am in the process of making appointments and getting the referrals I need to follow this particular path. It means waiting several months, but my melancholy has mostly lifted; if this is the right route, if this takes me to an answer, if it can improve my health across the board, the wait will be worth it.

*Not in terms of his knowledge of his specialty, but regarding his human interaction and estimation of my intelligence.

**Once I have a little more information on myself, if it turns out my hunch is correct, we’ll be pursuing this for Scooter too.


Mad said...

Wow. It's amazing you got to the bottom of it. I hope this ends up providing the answers and remedy you need.

When they discovered my hypothyroidism, my levels were at 8. I'm not entirely sure what they are now but I doubt they are as low as 2 let alone 1.5.

Aliki2006 said...

Good for you for pursuing this. Sometimes you just have to take matters into your own hands--too many doctors just don't want to be bothered.

kgirl said...

knowledge is power. you are one powerful woman.