pre-CR biomarkers - NEED HELP

[kinase]

Hello.

I've looked at Tests and biomarkers page and i've made my own list, but I know I'm going to forget something, it's like going to the grocery store, you always forget something.

 

What more data would have you gathered before entering CR knowing what you know today?

 

quick question:

- what is the difference between rT3 and T3? Why do we need to test rT3?

 

I'm going to get blood work done in 1 weeks or so.

[Michael R]

v

What more data would have you gathered before entering CR knowing what you know today?

I would certainly get everything on the list except DHEA(s): the result on which that was based has emerged to be a fluke.

 

I would really strongly encourage you to get IGF-1 and IGF-BP3 (and, if you can afford it and be patient, get it tested twice separated by at least a week): this is likely an extremely important CR biomarker, and baseline data is helpful to interpretation.

 

I would say the same about free and total testosterone if you're male (and here baseline data is even more important): in addition to being tied up in the CR endocrinology, you will want to know in future if a low T measurement relates to aging, pathology, or CR. (Important: you can take the standard test for your baseline test, but for all CR tests you really want testosterone by LC/MS-MS, as your T is likely too low to be reliably assayed by the usual method. Life Extension offers LabCorp's test #070038 for $48, but you can't order it online: have to call in and ask the blood lab for it).

 

Granted the ongoing controversy and confusion over CR-associated glucose intolerance, I would also strongly encourage you to get a baseline OGTT — preferably a 2-hour test with a draw/measurement at the half-hour mark. This isn't Life Extension's standard OGTT, but if you talk directly to the blood lab they can put instructions into your requisition to draw at that point instead of at the 4 hour mark as is their usual protocol.

 

On the off chance that you're a discordant responder, I would also suggest getting either apoB or an NMR LipoProfile for LDL particle number.

 

- what is the difference between rT3 and T3? Why do we need to test rT3?

 

Reverse T3 (RT3 or REVT3) is a biologically inactive form of T3. Normally, when T4 is converted to T3 in the body, a certain percentage of the T3 is in the form of RT3. When the body is under stress, such as during a serious illness [or CR -MR], thyroid hormone levels may be outside of normal ranges even though there is no thyroid disease present. RT3 may be elevated in non-thyroidal conditions, particularly the stress of illness [or CR -MR]. ... Use of the RT3 test remains controversial, and it is not widely requested.

[kinase]

Thanks a lot!