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Doping with performance-enhancing drugs in both amateur and professional sports has become an increasingly growing problem. As the technology to detect drugs and illegal substances has improved, an increased number of athletes are being caught out as the limits of detection are more significant. Each sport has its own rules and regulations as to which substances are banned, but with the enhancement in drug detection, it has become harder for sportsmen and women to misuse drugs in athletics.
Techniques look at not only banned substances but metabolites that would show up after the main compounds have broken down. Samples that can be tested include blood, saliva and urine, with a wide range of techniques being used depending on the biological sample being analyzed.
Definition of Doping
It is not just the use of prohibited substances that is considered doping. The World Anti Doping Agency (WADA) has a strict code that defines the categories considered doping. The types of doping violation defined by WADA include:
- The presence of a prohibited substance or its metabolites in a sample
- Evading or refusing to give a sample
- Missing tests and failing to provide information on missed tests
- Tampering with samples or any part of the doping process
- Possession of a prohibited substance or method
- Trafficking of a banned substance or method
- Administering or attempting to deliver prohibited substances or methods
- Assisting and covering up any intentional complicity
Over the years, there have been many well-publicized cases of doping in sport. Due to the nature of the sport, drug doping in athletics is quite common, but a lot of other sports also suffer at the hands of drugs cheats. Sports such as cycling, swimming, gymnastics, baseball weight-lifting and martial arts all have famous examples.
One of the biggest doping scandals to date is Russian doping scandal, which saw some athletes banned from the 2016 summer Olympics and only a select few being allowed to compete under a neutral flag at the 2018 winter Olympics.
To this date, there have been 47 medals stripped from Russian athletes that have competed at the Olympic level alone, as well as more than 200 athletes being caught out for doping, which is the highest of any country.
Outside of the Russian team, there have been many famous track and field athletes banned for doping. Olympic sprinting has a lot of cases of athletes testing positive for banned anabolic steroids. Cycling is another major sport that has seen instances of doping.
Doping in martial arts and boxing includes not only the steroids and growth hormones banned in other sports, but also recreational drug use is common due to the numbing effects of the drugs. Mixed martial arts are fraught with doping scandals, with many fighters having titles stripped and being given suspensions that prevent them from fighting.
Common Drugs Abused
The types of drugs and substances that are abused include prescribed medications, recreational drugs, stimulants, steroids and hormones. Examples of the banned substances include:
- Prescribed medication: This is an area that is commonly abused due to how easy it is to get false prescriptions.
- Recreational drugs such as alcohol, narcotics, marijuana and all cannabinoid derivatives
- Stimulants such as amphetamines and cocaine
- Testosterone: Although testosterone is an endogenous steroid, athletes are tested to make sure they do not have excess exogenous levels of testosterone in their bodies.
- Anabolic Steroids: One of the main groups of banned substances are anabolic steroids. They are synthetically manufactured drugs that mimic testosterone.
- Human Growth Hormone (hGH): hGH is a peptide hormone commonly used as it is hard to detect due to having such a short half-life. It is not a steroid but has an anabolic effect similar to steroids.
Gas Chromatography and Gas Chromatography-Mass Spectrometry
Gas chromatography was one of the first analytical techniques used to test doping back in the 1970s. It is a technique that separates thermally stable volatile compounds within a mixture. Compounds are separated using differential migration of the sample through a column containing a solid or a liquid stationary phase by a gaseous mobile phase.
Gas chromatography-mass spectrometry (GCMS) combines gas chromatography and mass spectrometry for qualitative and quantitative results. The use of mass spectrometry allows for a spectral profile of drugs.
By the time the Olympic Games in 1988 came about, a GCMS method to detect stimulants, narcotics and beta-blockers had been developed. The technique is now commonly used to identify steroids and volatile drugs such as amphetamines in the samples submitted by athletes.
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Liquid Chromatography-Mass Spectrometry
Liquid chromatography-mass spectrometry (LCMS) combines liquid chromatography and mass spectrometry techniques. Unlike gas chromatography, liquid chromatography separates analytes in a mixture by using a liquid mobile phase and solid column stationary phase. LCMS has allowed for the detection of previously untraceable drugs as well as fast extraction and analysis procedures.
LCMS is used in drug doping to detect drugs such as diuretics, beta-blockers, and long-acting beta-2 agonists. As well as looking at small drug molecule detection, LCMS can be used to study metabolism pathways and EPO glycosylation pathways. Peptide hormones such as cross-linked hemoglobins are also unable to be analyzed by techniques such as GCMS, so LCMS is used instead.
One of the simplest ways to detect steroids and hormones in samples is through a biomarker test. Biomarkers are measurable markers by which diseases can be identified.
The Athlete Biological Passport is a common way of continually monitoring irregularities in biomarkers. Commonly used biomarker tests for drug abuse look for hGH and erythropoietin (EPO) abnormalities.
The hGH biomarker test looks at biological markers of hGH activity, such as IGF-I and procollagen type III amino-terminal propeptide (P-III-NP). Testing for IGF-1 and P-III-NP allows for an increased detection time of seven days due to the longer serum half-lives. EPO biomarker tests look at hemoglobin, hematocrit, and reticulocyte levels.
Isoform Differential Immunoassay Tests
Isoform Differential Immunoassays, also known as Isoforms tests, were first introduced in 2004. Since total levels of hGH in circulation are naturally variable and can fluctuate easily, it is difficult to use a test that solely measures increased total hGH concentrations for doping.
A common doping method with hGH is to dose with recombinant hGH (recGH), which would show a variation in the different isoforms of hGH present in a sample. The Isoform Test allows for the detection of the changes in the proportions of the hGH isoforms after a recGH injection.
Blood transfusions are one way that athletes managed to evade positive doping tests for many years. New tests that can detect fraud at the RNA level have been developed by both Duke University and The University of Brighton.
The team at Duke University showed how micro RNA (miRNA) testing could tell apart new and old red blood cells, due to the discovery of the 18-nucleotide miR-720 showing a predictable pattern as blood aged.
The researchers at The University of Brighton are looking into the fingerprints that drugs leave behind in RNA. By analyzing the genetic markers in a sample, the banned substances can be detected weeks instead of hours or days after being taken.
References and Further Reading
Reardon, Claudia, and Shane Creado. “Drug Abuse in Athletes.” Substance Abuse and Rehabilitation, 2014, p. 95., doi:10.2147/sar.s53784.
Thevis, M., and W. Schanzer. “Examples of Doping Control Analysis by Liquid Chromatography-Tandem Mass Spectrometry: Ephedrines, Receptor Blocking Agents, Diuretics, Sympathomimetics, and Cross-Linked Hemoglobins.” Journal of Chromatographic Science, vol. 43, no. 1, 2005, pp. 22–31., doi:10.1093/chromsci/43.1.22.
Siebert, David M., and Ashwin L. Rao. “The Use and Abuse of Human Growth Hormone in Sports.” Sports Health: A Multidisciplinary Approach, vol. 10, no. 5, 2018, pp. 419–426., doi:10.1177/1941738118782688.
Stojanović, Emilija, and Dragan Radovanović. “Historical Development of Analytical Methods for Anti-Doping Control.” Physical Education and Sport Through the Centuries, vol. 4, no. 1, 2017, pp. 15–23., doi:10.1515/spes-2016-0018.
Yang, Wen‐Hsuan, et al. “Angiogenin‐Mediated TRNA Cleavage as a Novel Feature of Stored Red Blood Cells.” British Journal of Haematology, vol. 185, no. 4, 2018, pp. 760–764., doi:10.1111/bjh.15605.
University of Brighton (2019) World recognition for university research to beat the cheats. [Online] Available at: https://www.brighton.ac.uk/news/2019/world-recognition-for-university-research-to-beat-the-cheats (Accessed on 25 August 2020).
WADA. [Online] Available at: https://www.wada-ama.org/ (Accessed on 25 August 2020).