Evidence map›Paper›PMID 39279345›Full record

ArticleDrug testing and analysis2025

Improving the Determination of Carbon Isotope Ratios of Endogenous Steroids Found in Human Serum.

Thomas Piper, Mario Thevis

Abstract readValidation Study
In one paragraph

Article in Drug testing and analysis, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed.

  1. Interpol review of forensic drug chemistry, 2022-2025.Forensic science international. Synergy · 2026
    Review
  2. Review
  3. Review
  4. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors.

Thomas PiperCenter for Preventive Doping Research-Institute of Biochemistry, German Sport University Cologne, Köln, Germany.ORCID https://orcid.org/0000-0002-7462-6693
Mario ThevisCenter for Preventive Doping Research-Institute of Biochemistry, German Sport University Cologne, Köln, Germany.ORCID https://orcid.org/0000-0002-1535-6451

Funding

Bundesministerium des Innern, für Bau und HeimatManfred-Donike Institute for Doping Analysis
6 · The paper itself

Abstract

The determination of serum concentrations of testosterone (T) and 4-androstenedione (A4) was implemented into the steroidal module of the Athlete Biological Passport in 2023. Monitoring T, A4, and the ratio of T/A4 in a longitudinal manner enables the detection of the misuse of low-dose T administrations especially in female athletes, whereas urinary markers of the steroid profile may not be influenced significantly. In contrast to the urinary steroid profile, knowledge on confounding factors regarding serum concentrations of T and A4 is yet comparably scarce, and corroborating exogenous sources of the target analytes by isotope ratio mass spectrometry (IRMS) is desirable. In a recent study, it was demonstrated that carbon isotope ratios (CIRs) of serum steroids can be determined if analyte concentrations permit. The therein-employed method utilized 2D-GC/IRMS, and only a limited number of potential endogenous reference compounds were available. The here-presented approach uses complementary analyte purification strategies, addressing previous limitations. A high-performance liquid chromatography cleanup was developed and fully validated for serum steroids in order to enable all doping control laboratories to potentially implement this method alongside existing protocols for urinary steroids. Besides the already-investigated endogenous steroids cholesterol, dehydroepiandrosterone sulfate, androsterone sulfate, and epiandrosterone sulfate, two additional steroids were included in the test menu, namely, pregnenolone sulfate and 5-androstene-3β,17β-diol sulfate. Serum steroid concentrations down to 25 ng/mL were found to allow robust CIR determinations, and a reference population encompassing 124 male and female athlete samples was investigated to enable the calculation of population-based thresholds for all relevant steroid combinations.

Indexed as

AndrostenedioneCarbon IsotopesSteroidsSubstance Abuse DetectionTestosteroneChromatography, High Pressure LiquidDoping in SportsFemaleGas Chromatography-Mass SpectrometryHumansLimit of DetectionMaleAndrostenedioneCarbon IsotopesSteroidsTestosteronecarbon isotope ratiosdoping controlsendogenous steroidshuman serumisotope ratio mass spectrometry

Identifiers

PMID39279345
PMCPMC12209692

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.