Wildly Different E2 Numbers - LabCorp vs. Quest

[jkozlow3]

I won't bore everybody with details and fluff - the numbers speak for themselves. Bottom line, Quest and LabCorp E2 numbers are nowhere near each other based on recent lab work I had done (Quest numbers were 2x LabCorp numbers). Be careful if you are managing E2 with only a single lab!

Pre-TRT

Quest:
Total T: 254
E2 (non-sensitive / immunoassay): 26 (range: <= 39)


A couple of months into TRT (tested at trough on E3.5D schedule)

Quest:
Total T: 719
E2 (non-sensitive / immunoassay): 39 (range: <= 39)
E2 (ultrasensitive / LC-MS/MS): 54 (range: < 29) - note: this was HIGHER than the non-sensitive value which is the opposite of what most people report!


At this point, I decided to micro-dose Arimidex by dissolving in vodka. I slowly tweaked my dose and tested every couple of weeks (didn't want to crash my E2) until my Quest E2 was in the mid-20s. This was accomplished with a VERY low dose of Arimidex of ~0.25 mg/week based on my calculation.

I realize that the need for Arimidex is controversial and many would say that I didn't need it, but that's not what this thread is about.

Last week, I tested E2 at BOTH LabCorp and Quest while on a micro-dose of Arimidex. I order my own lab work via UltaWellness (Quest) and DiscountedLabs (LabCorp). The blood was drawn 15 minutes apart.


October 2018 Results (drawn 15 minutes apart)

Quest:
E2 (non-sensitive / immunoassay): 24 (range: <= 39)

LabCorp:
E2 (non-sensitive / immunoassay): 12.3 (range: 7.6 - 42.6)
E2 (sensitive / LC-MS/MS): 13.7 (range: 8-35)


If the LabCorp results are to be believed, I definitely did not need the Arimidex.

I'm guessing the Quest results are off, but I have no way of confirming that. If the Quest results are 2x the LabCorp results, then my starting E2 (LabCorp) likely would have been ~13 before TRT. This makes sense since my pre-TRT T level was ~250. T converts to E2, so it makes sense that my E2 level would have been low before starting TRT (since I had no T) vs. the 26 that Quest claimed pre-TRT.

Be careful when using labs from one provider to manage E2! It seems like we're in a really sad state when it comes to E2 testing for men and getting reliable, consistent results. Not just based on my experience, but from the experience some of the other members of this board have posted over the years as well.

 

[Nashtide]

Labs obviously vary from each other. I've used Quest for over three years and my results are consistent and expected. IOW, when I've increased T dose all numbers went up. When I changed AI dose the test either rose or fell accordingly. How does testing in both labs help? How do you choose which results are correct? We already over complicate this process, I'm not going to start worrying about this topic.

 

[jkozlow3]

How does testing in both labs help?

Because one of them is clearly wrong. If 20-something is the sweet spot for E2, then it definitely matters. According to one lab, I likely would have been in this sweet spot without an AI. According to the other lab, I was well over this sweet spot. This is a big problem. I am simply trying to alert people to this issue.

Again, I realize that opinions on E2 differ and not everyone agrees with shooting for an E2 in the 20-something range. That's not the point of this thread. But if you are shooting for a specific number/range and one lab gives results that are 2x the value of the other lab, that's a PROBLEM. Do what you want with this info - I'm simply raising awareness.

 

[Nashtide]

Because one of them is clearly wrong. If 20-something is the sweet spot for E2, then it definitely matters. According to one lab, I likely would have been in this sweet spot without an AI. According to the other lab, I was well over this sweet spot. This is a big problem. I am simply trying to alert people to this issue.

Again, I realize that opinions on E2 differ and not everyone agrees with shooting for an E2 in the 20-something range. That's not the point of this thread. But if you are shooting for a specific number/range and one lab gives results that are 2x the value of the other lab, that's a PROBLEM. Do what you want with this info - I'm simply raising awareness.

Okay, but how do you decide which lab is correct? Are you choosing the one that has results that fit what you want to see? Both labs are highly regarded. If you had 3 labs and one was an outlier then I'd understand. In this case, I don't see how this helps since you can't offer a scientific reason for deciding which lab is correct.

 

[jkozlow3]

Okay, but how do you decide which lab is correct? Are you choosing the one that has results that fit what you want to see? Both labs are highly regarded. If you had 3 labs and one was an outlier then I'd understand. In this case, I don't see how this helps since you can't offer a scientific reason for deciding which lab is correct.

I have no idea. That's the frustration. One lab is clearly wrong and has no business testing E2 in men.

 

[fifty]

Lab work is like sports technology. Just because it prints out a number people think it’s right. I trust this stuff about as far as i can throw it. #theranos #wizardOfOz

 

[Vince Carter]

Well you're not even using the correct tests more than half the time so there's that. And, you're time and effort would be much better spent using one lab and getting the correct tests but great first post on your part, really well done attempt to sound smart. <sarcasm>

 

[jkozlow3]

Well you're not even using the correct tests more than half the time so there's that. And, you're time and effort would be much better spent using one lab and getting the correct tests but great first post on your part, really well done attempt to sound smart. <sarcasm>

Really?? Way to put me down for trying to alert members that LabCorp and Quest numbers are significantly different.

Some of those labs WERE the sensitive/ultra. And those aren’t exactly foolproof either from what some members have posted. Several people have said they got bizarre results with the sensitive E2 test over the years. I’ve been reading posts about TRT for months.

You said I’d be better off using one lab. Well, that’s exactly what I did for 6 months of TRT. Turns out that lab (Quest) reports E2 numbers that are significantly higher than LabCorp. So one lab led me to believe I should experiment with an AI where as according to the other lab I likely wouldn’t have had an E2 problem at all. So I guess I’m just trying to “sound smart” in your words by warning members of this discrepancy? Thanks Vince.

 

[Nashtide]

Really?? Way to put me down for trying to alert members that LabCorp and Quest numbers are significantly different.

Some of those labs WERE the sensitive/ultra. And those aren’t exactly foolproof either from what some members have posted. Several people have said they got bizarre results with the sensitive E2 test over the years. I’ve been reading posts about TRT for months.

You said I’d be better off using one lab. We’ll, that’s exactly what I did for 6 months of TRT. Turns out that lab (Quest) reports E2 numbers that are significantly higher than LabCorp. So one lab led me to believe I should experiment with an AI where as according to the other lab I likely wouldn’t have had an E2 problem at all. So I guess I’m just trying to “sound smart” by warning members of this discrepancy. Thanks Vince.

I guess what I'm still trying to understand about this situation is WHICH lab do you believe? You still haven't answered this question. My guess is 99% of folks are going to choose to believe the results that fit their belief system. IOW, if you are against the use of an AI you will automatically assume the lab that reported the lower E2 is the correct result and vice versa. As I stated before, unless you simultaneously test 3 reputable labs, you CANNOT know which results are valid. Therefore this doesn't really help the matter. Please help me understand.

 

[jkozlow3]

I guess what I'm still trying to understand about this situation is WHICH lab do you believe? You still haven't answered this question. My guess is 99% of folks are going to choose to believe the results that fit their belief system. IOW, if you are against the use of an AI you will automatically assume the lab that reported the lower E2 is the correct result and vice versa. As I stated before, unless you simultaneously test 3 reputable labs, you CANNOT know which results are valid. Therefore this doesn't really help the matter. Please help me understand.

Nashtide,

I am not sure I’m qualified to make a decision as to which lab is correct and which one is wrong. I was hoping that perhaps this thread would generate some discussion where others shared their experiences.

Mainly, I was trying to raise awareness of the Quest vs. LabCorp discrepancy. I have no idea which lab is correct but one of those labs has no business testing E2 in males and is providing incorrect results. If the numbers were within 20-25% of each other, fine. But 100% variance?? That’s unacceptable.

 

[Nashtide]

Nashtide,

I am not sure I’m qualified to make a decision as to which lab is correct and which one is wrong. I was hoping that perhaps this thread would generate some discussion where others shared their experiences.

Mainly, I was trying to raise awareness of the Quest vs. LabCorp discrepancy. I have no idea which lab is correct but one of those labs has no business testing E2 in males and is providing incorrect results. If the numbers were within 20-25% of each other, fine. But 100% variance?? That’s unacceptable.

Okay, so I've exclusively used Quest for 3+ years with no issue. I prefer the consistency of getting my labs from the same place and testing under the same conditions. I'm very comfortable that my results have always been correct.

 

[blackebob]

Did you post this question to both Lab companies? Perhaps they would have a logical answer as to why this occurred? I would be interested in their answer. Seems to me that is the only way to find out.

 

[jkozlow3]

Did you post this question to both Lab companies? Perhaps they would have a logical answer as to why this occurred? I would be interested in their answer. Seems to me that is the only way to find out.

I have not. I will look into how I might do this.

 

[blackebob]

Quest patient advocacy line
8004207225

 

[jkozlow3]

Quest patient advocacy line
8004207225

Thanks. Ideally, I'd like to email both companies and explain the situation and my results (vs. calling and speaking to a low-level employee which will probably accomplish nothing). I can't seem to find a good email address with either company to do so however. Email addresses exist on their websites, but I don't think any of the published addresses will route my email to the right department.

 

[blackebob]

talking to someone at quest is easier said than done, and usually results in 40 mins of frustration. That number was for quick access to a live person who could give you an email. It is the only number I use now, or you could try messaging on FB.

 

[blackebob]

hy Do Results Differ From Lab To Lab?
Another question frequently asked is why hormone results from LabCorp are different than results from Quest for the same hormone test.

At Life Extension, we often encounter customers who are concerned because they received a hormone result from Quest that their doctor ordered, and it doesn’t match the result from Life Extension using LabCorp.

What most people don’t realize is that there is no standardization between commercial blood labs for hormone testing. It is a common assumption that all labs are testing hormones the exact same way and that the numbers should be the same between labs. Unfortunately, this is not the case. Because different labs use different methods, the results are not directly comparable. And since the methods, the reagents, and the equipment are all different, the number you get from one lab may not be comparable to the number from another lab—even though the name of the test is the same.

This is so frustratingly common that when I read a study on hormone testing, the first thing I do is go to the “Materials and Methods” section to see which lab did the test and what methodology was used. Only then can I put the hormone levels reported in the study into the proper perspective. This lack of standardization between labs makes it very frustrating for clinicians and researchers alike.

To make matters worse, there are also multiple ways to test the same hormone within each lab. Testosterone is the classic example. The two primary methods used to assess testosterone in the blood are an immunoassay methodology or liquid chromatography coupled with tandem mass spectrometry. This situation leads to a lot of confusion among patients and doctors alike.

The best solution is to stick with the same lab and use the same methodology each time.

Stolen from the web.

 

[jkozlow3]

Why Do Results Differ From Lab To Lab?
Another question frequently asked is why hormone results from LabCorp are different than results from Quest for the same hormone test.

Yes, BUT...

My Quest E2 was basically over the range a couple of months into TRT. Technically, my E2 was 39 on a trough day which was at the very top of the range. My ultra-sensitive result was WELL above the range. I also had another test result on a peak day (not trough day) of 46 with Quest that I didn't list in my original post. The 46 was done with immunoassay (non-sensitive) a couple of days before the 39 result. So I was getting results in the 39-46-54 range and was definitely "riding high" and above Quest's range.

At that point I started experimenting with Arimidex, shooting for the 20-30 sweet spot you read about everywhere.

Once I reached that sweet spot (24 with Quest), LabCorp had me at the very bottom of their E2 range. The LabCorp results were half the Quest values and I was at very different spots in the range.

So I brought my E2 down from 39 down to 24 with Arimidex on my Quest labs...this is roughly a 38% decrease in my E2. 39 is 62% higher than 24.

My LabCorp E2 was ~13. If we add 62% to this, my LabCorp E2 would have theoretically been ~21 without using an AI. If my labs had indicated an E2 value of 21, I would have NEVER started experimenting with an AI.

This is my point, and this is the problem. I don't expect LabCorp and Quest results to match identically but one lab shouldn't be giving me a result that is DOUBLE the other lab when they are using the same units and similar ranges. My Quest results led me to believe I had a potential E2 problem where as LabCorp would have likely led me to believe I most certainly did not.

If other men are using Quest exclusively, they could mistakenly be treating a non-existent E2 issue - just like I was. Then again, LabCorp could be the lab that is in error. Low E2 symptoms and high E2 symptoms are virtually identical for many men, so it's not that easy to go by symptoms alone.

The point of my thread was to raise awareness to this issue and to the discrepancy between the 2 labs - at least in my case. Perhaps something unique in my blood could cause a larger discrepancy or a false elevation that others may not experience. I have no idea. But in my case at least, something is wrong.

Could you imagine if you went to the doctor and they looked at your glucose or A1C and were told you had diabetes based on a lab result from Quest when LabCorp (had it been tested) would have given you a result that was well within range? You would be mistakenly diagnosed as a diabetic (assuming the lower LabCorp results were the accurate ones) and could end up on diabetes treatment for life. That's exactly what has happened here in my scenario. One lab caused me to seek E2 management - possibly due to erroneous results.

Again, I have no idea which lab is reporting the correct values, but I stand by my statement that this could potentially be a large problem for men on TRT if they aren't cross-referencing labs to ensure that they even have an E2 issue in the first place (according to more than one lab) before starting an AI.

 

[Nelson Vergel]

Much of the result variation has to do with how long the specimen sits before being processed, in addition to the environment where its stored and the shipping process (ie time of year, exposure to temperatures, etc).
This variation probably applies to many biomarkers and all labs unless the specimen is processed on the spot.

 

[DragonBits]

Because one of them is clearly wrong. If 20-something is the sweet spot for E2, then it definitely matters. According to one lab, I likely would have been in this sweet spot without an AI. According to the other lab, I was well over this sweet spot. This is a big problem. I am simply trying to alert people to this issue.

Again, I realize that opinions on E2 differ and not everyone agrees with shooting for an E2 in the 20-something range. That's not the point of this thread. But if you are shooting for a specific number/range and one lab gives results that are 2x the value of the other lab, that's a PROBLEM. Do what you want with this info - I'm simply raising awareness.

technically, both labs could be wrong. One lab could be over estimating E2, one could be underestimating E2.

It would have been more clear if you had always used the LC-MS/MS method all the time with both labs.

When I read research papers on the subject I get the idea of how complicated it gets.

Here is one such paper on two major methods that are widely used to measure E2: indirect and direct immunoassays. In comparison to the gold standard of LC-MS/MS.

Comparison of Methods to Measure Low Serum Estradiol Levels in Postmenopausal Women

RESULTS: Three assays detected E2 in all samples, whereas E2 was detected in only 53% and 72% of samples by 2 other assays. All 5 assays had positive biases, ranging from 6% to 74%, throughout their ranges. CVs were lower with 4 immunoassays than with LC-MS. LC-MS, but none of the direct immunoassays, correlated with serum testosterone and sex steroid–binding globulin.

Comparison of Methods to Measure Low Serum Estradiol Levels in Postmenopausal Women | The Journal of Clinical Endocrinology & Metabolism | Oxford Academic

NOTE that there isn't really a male Vs female E2 test, the real key is expected level of E2.

Postmenopausal Women have low levels of E2 similar to men, and experience the same sort of inaccurate measurements using immunoassays.

If you goggle the subject, you see a lot of discussion about reasons why immunoassay may not be accurate, both from one time to another in the same lab and between different labs. The discussions become very technical.

I wouldn't have used an AI for Quest E2 (ultrasensitive / LC-MS/MS): 54 (range: < 29). Maybe if you had done a Labcorp LC-MS/MS at the same time, it would have shown similar results.

I would have waited a 2-4 weeks and tested again. Even if I had some mild symptoms of E2 such as water weight gain.

I have used at least 3-4 different lab companies, Labcorp, Quest, ACL and whatever the hospital used, which I don't know what that was. I wasn't my choice, sometimes it's just beyond my control.

I actually look more at trends and less at absolute numbers, though I pay attention to both.