- Re: Lab results What are the norms?

[Guest guest]

dalkharusy wrote:

> In January, 2003 I received a clean slate after my scan. I have had

> two radiation treatments in the last 1 1/2 years. My lab report on

> my levels are TSH 0.05; T4 15.8; Tg less than 0.9

> I am taking 0.150 levoxyl. My oncologist wants to decrease my dose

> to 0.125. What are the normal levels for the TSH and T4 as well as

> the Tg? Can you direct me to some documentation on this?

General protocol calls for a TSH of less than .10, but there's some flexibility

depending on risk factors and other health issues. T4 levels are expected to

in the high end of normal, or sometimes a little

higher; you'd have to check you lab's values to see what their normal range is,

but I'm guessing it's lower than 15.8.

There's not a lot a whole lot on T3 and T4 levels, mostly because TSH is the

level we focus on most. Generally, we aim to get our TSH suppressed (<.10 in

most cases), and then look at the other numbers,

knowing that they'll most likely be in the higher range of normal, or possibly

even higher.

Once our TSH has stabilized where we want it to be, we look at the other

numbers. The biggest concern about an elevated T4 is that long term T4

elevation can lead to (or speed up) bone loss. So we play

this little game of numbers, trying to balance the need for TSH suppression

against the need to have our T3/T4 numbers as close to normal as possible.

.... from Synthroid prescribing information (page 4):

" Effects on bone mineral density - In women, long-term levothyroxine sodium

therapy has been associated with increased bone resorption, thereby decreasing

bone mineral density, especially in post-menopausal

women on greater than replacement doses with increased serum levels and urinary

excretion of calcium and phosphorous, elevations in bone alkaline phosphatase

and suppressed serum parathyroid hormone levels.

Therefore, it is recommended that patients receiving levothyroxine sodium be

given

the minimum dose necessary to achieve the desired clinical and biochemical

response. " http://synthroid.com

Dr. Ain has written:

" It seems prudent to consider this level of thyroid

hormone therapy to enhance osteoporosis risk factors if sufficient

other such factors exist (i.e. post-menopausal female without

estrogens, very thin, Caucasian, lack of weight-bearing exercise,

poor calcium intake, low levels of vitamin D, etc.). The

hypothesized mechanism of this effect is related to altering the cell

cycles of the bone cells which make bone (osteoblasts) and consume

bone (osteoclasts). For those members well-grounded in Cell Biology,

a large amount of published research can be read in your nearest

medical library. The decision to use slightly higher levels of

thyroid hormone to suppress TSH is based on a careful consideration

of its known benefit in suppressing thyroid cancer and preventing

recurrences or tumor progression, compared to a variety of minor

risks which can be minimized with careful attention to minimizing

risks and optimizing health. "

-- see entire letter at http://groups.yahoo.com/group/Thyca/message/24955

> As a note of caution...when I was off my meds before the scan my

> cholesterol and Trigl etc. were so high I was a prime candidate for a

> heart attack. They rechecked after a month back on my meds. My

> levels dropped to acceptable limits. They weren't sure of the

> connection being hypo but I feel any one who is going off their

> medicine before radiation and scans should be very cautious. Don't

> exert yourself!

I'm surprised that your doctors " weren't sure of the connection " between

cholesterol and triglyceride levels and elevated TSH; it's pretty standard

information, and it shouldn't have been a surprise that

those levels were elevated while you were hypo. My endo doesn't even bother

checking my cholesterol while I'm off meds, because it's a temporary and

therefore basically meaningless number.

-

NYC