LOW sex hormone binding globulin (SHBG) - what does it mean?

[pwallace]

Can someone explain to me how SHBG works? And how it relates to prostate cancer? Pouring over my husband's charts & I see that Dr. Ahlering was closely monitoring this protein, but he never mentioned why - for example, sometimes the only other thing he would test in addition to testosterone was his SHBG number.

For reference, right before surgery, his SHBG was 12.

And then in December of '17 it as 11.

March of '18 it was 10.

June of '18 it was 9.

August of '18 it was 8.

Dec of '18 it was still 8.

Feb of '19 it was 7.

March of '19 it was still 7.

That was the last time we tested with Dr. Ahlering, and his current doctor hasn't tested his SHBG- I can only imagine that it has continued to go down, though (as it was on a downward spiral before)!

What does this mean (if anything)? Is his liver out of whack? this a marker for insulin resistance? or a metabolic syndrome?

Can't help but think it might be part of the puzzle.

Thanks!

ps. He's had low T (before surgery & after), but even with higher T numbers the SHBG remains low.

pps. He's not obese or overweight in any way (I know that's related to low numbers as well).

[Tall_Allen]

SHBG is a protein that "captures" excess testosterone. Only the the testosterone that is not captured, called "free testosterone," is available to activate the androgen receptor. If the "total T" is at castrate level, it has no significance.

[pwallace in reply to Tall_Allen]

but that's the weird thing, the total castrate level was never at castrate levels, it was always hovering around 140, but even when it was as high as 788 his SHBG was at an 8. i see most guys writing about ways to lower it, but no one ever writing about it being this low.

[pwallace in reply to pwallace]

sorry i meant the total testosterone level!

[Tall_Allen in reply to pwallace]

I don't understand what you are seeing as a problem. It just means his % free testosterone was higher - not very important.

[pwallace in reply to Tall_Allen]

ok good to know- it's been flagged on his paperwork for years, so i've always been curious about its role (if any)! thanks allen

[Hidden in reply to pwallace]

Keep asking Summer. I just learned this myself from T_A . There are no stupid questions because you’re working from love . Great job ! Peace to Tristen!

[Hidden]

You can get the Free and Bioavailable Testosterone counts via this online calculator: issam.ch/freetesto.htm

[pwallace in reply to Hidden]

thanks!

[LowT in reply to pwallace]

These are best measured/not calculated. In my experience the calculated is not very accurate.

[Hidden in reply to LowT]

Had one with all 3 parameters measured and it came very close.

[LowT in reply to Hidden]

Are you sure the lab report wasn’t itself a calculated value? The test order must specify measured to be sure what you are getting is measured and not calculated.

[Hidden in reply to LowT]

Yes, they usually write it in fine print and it was not 100% coincident (249 vs 261 in pmol/l for fT) unles they were using another formula.