AN INTRODUCTION TO ANABOLIC STEROIDS

Thousands of people in the UK self-medicate with high-dose steroid regimes as a core component of their sports training, with the goal of enhancing their performance or image. Most are not involved in sport per se, it’s rather their workout. Research is ongoing to advance our understanding of the structural and personal factors that drive steroid use, how these factors may interact, and how they may be amenable to change. This article introduces anabolic steroids and discusses the associated risks to health and how this harm can be reduced.

BY MICHAEL J EVANS-BROWN BSC (HONS) AND JIM MCVEIGH MSC, RGN

INTRODUCTION For many of us the word ‘doping‘ evokes images of high- profile athletes falling from grace after testing positive for performance-enhancing drugs. Indeed, few people with an interest in sport could have failed to notice the “Dear Dwain” letter that was recently published widely in the media, written by the Bay Area Laboratory Co-Operative (BALCO) founder and owner, Victor Conte. The letter outlined the cocktail of performance-enhancing drugs that were given to the sprinter Dwain Chambers. The reality, however, is that the use of these drugs – in particular, injectable anabolic steroids – has, over the past few decades, transcended the world of elite sport to become widespread within the general population. In Britain, thousands of individuals, drawing from a diverse pharmacopoeia that is predominately of dubious origin, practise self-directed high-

dose polydrug regimes as a core component of their training, with the goal of enhancing their performance or image. Apart from the provision of sterile injecting equipment, there are currently limited opportunities for health professionals to engage with this population in order to reduce the risks to health associated with steroid use. This article aims to provide an introduction to anabolic steroids and covers what they are, whether they work, who uses them and why, how many people use them, the risks to health, and how the harm associated with these drugs can be reduced.

TESTOSTERONE AND ANABOLIC STEROIDS

Testosterone is the principal androgen in males 20

(andro = man, gen = to produce) and is required for normal physiological functioning and health. Indeed, it is a reflection of the diverse role that this hormone plays in the body that hypogonadal men (who fail to produce sufficient levels of testosterone or are insensitive to its effects) suffer from a range of disorders, including decreased muscle mass and strength, decreased bone mineral density, sexual/ reproductive dysfunction and disturbances to mood. Approximately 95% of testosterone is synthesised

in the Leydig cells of the testis, with the remainder being synthesised predominately in the adrenal glands (with some peripheral synthesis). Historically the actions of testosterone have been characterised as anabolic and androgenic. Anabolic effects are those that encompass the growth (protein building) of non-reproductive tissue, whereas androgenic effects are those involved in the differentiation, growth and maintenance of the reproductive system and secondary sexual characteristics in males. Although this system of classification is useful for conceptual purposes, it is important to recognise that testosterone acts on almost every tissue in the body and, therefore, plays a key role in a diverse number of physiological processes that fall outside of these classical categories, including actions on the immune system, cardiovascular function, bone homeostasis, and behaviour. Testosterone accomplishes its diverse role by acting both directly through classic genomic signalling pathways and rapid signalling pathways, and indirectly as a pro-hormone, which requires its conversion to the

bioactive metabolites 5a-dihydrotestosterone (a more potent androgen that serves to amplify the androgenic signal

of testosterone in some tissues) and 17b-oestradiol (an oestrogen that serves to diversify the action of testosterone through the oestrogen signalling pathways) (1). Anabolic steroids are a diverse group of synthetic drugs

that mimic, to varying degrees, the actions of endogenous testosterone. (These should not be confused with the corticosteroids, which are used to treat a diverse number of allergic, inflammatory and autoimmune conditions, such as asthma, eczema and Crohn’s disease.) It was the isolation, characterisation and synthesis of testosterone in 1935 that opened a new chapter in the nascent field of endocrinology. However, it was soon discovered that, when given orally or via parenteral injection, testosterone was metabolised rapidly by the liver, resulting in a short half-life and poor bioavailability, and thus limiting both scientific study and clinical use. Two main types of derivative were soon developed that circumvented this problem (Fig. 1): the orally

active 17a-methyltestosterone (the first oral 17a-alkylated steroid) and the injectable testosterone esters (such as testosterone propionate). Shortly after their synthesis, these new derivatives found

their way into clinical medicine as replacement therapy for individuals with common forms of male hypogonadism, where they exerted effects similar to those of endogenous

sportEX medicine 2008:38(Oct):20 -26