Physiological Effects and Disease Manifestations of Performance-Enhancing Androgenic–Anabolic Steroids, Growth Hormone, and Insulin

Anabolic-androgenic steroids (AASs) can be used to increase muscle mass and strength in adult males. Despite successful detection and convictions by sporting anti-doping agencies, they are still being used to increase physical performance and improve appearance. The adverse side effects and potential dangers of AAS use are well documented. Recent epidemiological research has identified that the designer drugs growth hormone (GH) and insulin are also being used because of the belief that they improve sporting performance. This chapter summarizes the classification of AASs, GH, and insulin as well as their prevalence and patterns of use. The physiology of GH and its pathophysiology in the disease states of deficiency and excess and in catabolic states are discussed and a distinction is made on the different effects between therapeutic use in replacement and abuse in a sporting context. The history, physiology, and pathophysiology of insulin in therapeutic replacement and its abuse in a sporting context are also described. A suggestion is made on potential mechanisms of the effects of GH and insulin.