Why Men need to request the sensitive, LC/MS assay for serum E2 measurement

Why Men need to request the sensitive, LC/MS assay for serum E2 measurement

A real World Example of why Men on TRT or using AAS might need to request the sensitive, LC/MS assay for serum E2 measurement

LC/MS assay offer greater sensitivity and lesser interference by other steroids.

The commonly used estradiol test may overestimate estradiol.

That test uses immunoassay technology that might be cross reactive to other compounds and cannot differentiate C-Reactive Protein (involved in inflammation) from estradiol, so it reads the combination of the two as estradiol.

This sensitive estradiol test is based on liquid chromatography/mass spectrometry (LC/MS), an assay technology that does not have that limitation.

Look at the difference here on this client from the same Blood Draw, the Lab he used did not do LC/MS assay in-house and so hence different Labs here.. but same client, same single blood draw, same day

AAS use at the time of this Blood Draw

500mg Test Enthate Week
500mg Nandrolone Week
12.5mg Aromasin EOD

Victor Black
#over50bodybuilding

J Clin Endocrinol Metab (2013) 98 (6): E1097-E1102.

Immunoassay-based techniques, routinely used to measure serum estradiol (E2), are known to have reduced specificity, especially at lower concentrations, when compared with the gold standard technique of mass spectrometry (MS). Different measurement techniques may be responsible for the conflicting results of associations between serum E2 and clinical phenotypes in men.

Objective:

Our objective was to compare immunoassay and MS measurements of E2 levels in men and evaluate associations with clinical phenotypes.

Design and Setting:

Middle-aged and older male subjects participating in the population-based Osteoporotic Fractures in Men (MrOS) Sweden study (n = 2599), MrOS US (n = 688), and the European Male Aging Study (n = 2908) were included.

Main Outcome Measures:

Immunoassay and MS measurements of serum E2 were compared and related to bone mineral density (BMD; measured by dual energy x-ray absorptiometry) and ankle-brachial index.

Results:

Within each cohort, serum E2 levels obtained by immunoassay and MS correlated moderately (Spearman rank correlation coefficient rS 0.53–0.76). Serum C-reactive protein (CRP) levels associated significantly (albeit to a low extent, rS = 0.29) with immunoassay E2 but not with MS E2 levels. Similar associations of immunoassay E2 and MS E2 were seen with lumbar spine and total hip BMD, independent of serum CRP. However, immunoassay E2, but not MS E2, associated inversely with ankle-brachial index, and this correlation was lost after adjustment for CRP.

Conclusions:

Our findings suggest interference in the immunoassay E2 analyses, possibly by CRP or a CRP-associated factor. Although associations with BMD remain unaffected, this might imply for a reevaluation of previous association studies between immunoassay E2 levels and inflammation-related outcomes.

from J Clin Endocrinol Metab (2013) 98 (6): E1097-E1102.