Growth Hormone and Insulin-Like Growth Factor-1

Abstract

Human growth hormone (GH) was first isolated from the human pituitary gland in 1945 and found to promote the growth of children with hypopituitarism. Since the formation of the World Anti-Doping Association, human GH has appeared on the list of forbidden substances. There is a significant amount of anecdotal evidence that human GH is misused by athletes to enhance performance, and there have been a number of high-profile cases of GH use in professional sport. GH secretagogues (GH-Ss), which increase GH secretion, and insulin-like growth factor (IGF-1), which mediates many of the effects of GH, are also misused, although there is less evidence for this. The effectiveness of GH, IGF-1, and GH-Ss as performance-enhancing drugs remains unclear. Evidence from studies of GH use in people with hypopituitarism show several desirable outcomes, including increased lean body mass, increased strength, and increased exercise capacity. These anabolic and metabolic properties, coupled with the difficulty in detecting them, make them attractive as agents of misuse. Studies in healthy young adults have also demonstrated a performance benefit with GH and IGF-1.

Links Between Testosterone, Oestrogen, and the Growth Hormone/Insulin-Like Growth Factor Axis and Resistance Exercise Muscle Adaptations

“…Following GH release, which induces the hepatic generation of IGF-1, circulating levels of IGF-1 and GH, feedback to the hypothalamus to inhibit further GH secretion (Daughaday, 2000 ). RE is the most potent physiological stimulus for GH release in both men (Nicholls and Holt, 2016 ; Fink et al, 2017 ) and women (Hymer et al, 2001 ), but little is known about how RE alters somatotroph content and function. GH begins to rise 10–20 min after commencing RE and peaks at the end of the RE (Gibney et al, 2007 ; Fink et al, 2018a ), returning to baseline values around 60 min post RE (Häkkinen and Pakarinen, 1995 ; Fink et al, 2018a ).…”

The Application of Nanosensors in Illicit Drugs Determination: A Review

“…Inhibiting the release of neurotransmitters, opioids such as codeine, tramadol, etc influence the actions of μ-and κopioid receptors to reduce pain [65]. Peptide hormones such as human growth hormone (GH), erythropoietin (EPO), insulin-like growth factors (IGF-1, etc) serve as anabolic substances that boost efficiency [66,67]. Such illicit drugs pose major global health problems, such as harm to athletes' health, and ethical problems, such as undermining the spirit of fair play at the bottom of athletic competition [57,68].…”

Annual banned‐substance review: analytical approaches in human sports drug testing

“…The physiological effects of growth hormone (GH), its mediator insulin-like growth factor-I (IGF-I), and GH releasing factors (including GH secretagogues (GHS) and GH releasing peptides (GHRPs)) and their role in the context of anti-doping efforts have been comprehensively reviewed by Nicholls and Holt, where myths and facts of GH are excellently contextualized. [103] In addition, aspects of analytical approaches including the so-called isoform and biomarker tests were discussed and the potential contribution of longitudinal monitoring of selected biomarkers as part of the ABP were argued. [35] Complementary to established test methods, the utility of combining biomarkers from transcriptional and (post)translational level, namely fibronectin 1 (FN1), RAB31, P-III-NP, and IGF-I was assessed.…”