I had a full thyroid panel done due to my pre TRT bloodwork showing a high TSH of 3.7. Does anyone have any input on these follow up labs? rT3 is a little high and T3 is a little below mid range, I don't think this warrants medication though, or am I wrong? Luckily all the antibody tests look good I believe?
free T4 1.34 ng/dL 0.82 - 1.77
TSH 3.54 uIU/mL 0.450 - 4.5
reverse T3 18.1 ng/dL 9.2 - 24.1
Thyroglobulin antibody <1 IU/mL 0.0 - 0.9
Thyroid Peroxidase (TPO) Ab 12 IU/mL 0 - 34
Triidothyronine, free, serum 3.0 pg/mL 2.0 - 4.4
In terms of hypo symptoms, skin on my body is very dry (altho skin on my face quite oily since starting TRT), and my joints are a little sore (TRT seems to be helping here, but slowly). Energy is good and stay lean/muscular very easily. I don't really gain much fat no matter what I eat, especially since starting TRT and pigging out lately lol. I'm on about week 5 of TRT.
Okay, at first glance we see Free T4 and Free T3, and where they sit in their respective reference ranges.
FT4 is at 54.7%
FT3 is at 41.6%
If all things were semi-optimal, you would probably want to see both values in the 50% to 80% area of the reference range, and hopefully both FT4 and FT3 would be sitting relatively close to each other (e.g., FT4 at 67% and FT3 is at 64%). Being that FT3 is essentially what makes the greatest impact on energy, metabolism, ATP, etc., you will no doubt be seeing the "Hypo" type symptoms you described when it is low.
On the Reverse T3, we are usually aiming to compare it against FT3 in a ratio analysis, taking FT3/RT3. Your ratio is 16.6. Ideally, most would probably want to see this >20.
To talk about "pooling". Yes, the RT3/FT3 ratio is used as a marker for pooling of T3, meaning FT3 isn't adequately making it to the cells in the body, thus it's pooling or building up redundantly. T4 converts to T3-FT3, and./but it also converts to RT3 via 5'deiodinase. When all things are in balance, T4 will convert adequately to T3/FT3, and there will also be "x" amount of T4 converting to RT3. When things are NOT in balance (iron, ferritn, cortisol primarily), the body will shift a bit and T4 will convert more RT3. This also happens in cases where the body needs to conserve energy, i.e., illness, injury, internal stress, etc.
Iron is pertinent with transporting T3 to the cells. When iron and/or ferritin is low, FT3 isn't getting circulated, so instead of T4 continuously converting downstream to T3/FT3, it will shift gears to convert more RT3 as mentioned above. So yes, as 'meanbreen' noted, they are indeed Two (2) different things, but they are closely correlated. FT3 doesn't always need to be elevated to be in a pooling state. Lots of times we actually see it elevated and pooling because men/women are taking medications like NDT, which is combination T4 & T3 (T2, and T1 also), so this is causing a spike in FT3 serum levels.
As Vince Carter has noted, the best thing right now would be to get that iron serum and ferritin labs. This should also be supported with electrolytes and vitamin D. Cortisol is also key, but for now start with the easier labs, unless you can get a 4x cortisol saliva test? Don't settle for a 1x morning blood draw for this test.
Lastly, many times various nutrients play a role in this as well. Selenium and iodine are crucial for 5-deiodinase conversion of T4 to T3 (not confused with it's counter related enzyme, 5'deiodinase with RT3). IMO, don't rule either one of these out. I have read cases where people have vastly improved subclinical hypothyroidism with only adding selenium to the mix. Plus, it works wonders with people struggling with elevated TPO.
Hope some of this helps, and at least gives you a few angles to research and think about. I'll try to keep an eye out for any updates or additional questions /comments.
