Growth hormones in sports refers to the use of

growth hormone Growth hormone (GH) or somatotropin, also known as human growth hormone (hGH or HGH) in its human form, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. It is thus important in ...

s (GH or HGH) for athletic enhancement, as opposed to

growth hormone treatment Growth hormone therapy refers to the use of growth hormone (GH) as a prescription medication—it is one form of hormone therapy. Growth hormone is a peptide hormone secreted by the pituitary gland that stimulates growth and cell reproduction. I ...

for medical therapy. Human Growth Hormone is a

prescription medication A prescription drug (also prescription medication or prescription medicine) is a pharmaceutical drug that legally requires a medical prescription to be dispensed. In contrast, over-the-counter drugs can be obtained without a prescription. The rea ...

in the US, meaning that its distribution and use without a prescription is illegal. There is limited evidence that GH doping improves athletic performance, although the perception that it does is common in the sporting community. Potential side effects of long term GH doping could mirror the symptoms found in sufferers of

acromegaly Acromegaly is a disorder that results from excess growth hormone (GH) after the growth plates have closed. The initial symptom is typically enlargement of the hands and feet. There may also be an enlargement of the forehead, jaw, and nose. Othe ...

, a disease in which the anterior pituitary gland produces excess growth hormone. These symptoms include swelling of the hands and feet, joint pain, fluid retention, and excessive sweating.

Overview

Human growth hormone occurs naturally in the

human body The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body. It comprises a head ...

where it functions by stimulating growth of essentially all tissues, including bone. Use of exogenous human growth hormone (HGH), via injection, was originally for medical purposes until athletes began abusing HGH with the goal of increasing their abilities. Before recombinant human growth hormone (rHGH) was developed in 1981, HGH was only available by extracting it from the pituitary glands of cadavers. The arrival of rHGH combined with other peptide hormone advancements has increased the availability of HGH on both the legitimate and black markets. The first description of the use of GM as a doping agent was Dan Duchaine's "Underground Steroid handbook" which emerged from California in 1982; it is not known where and when GM was first used this way. In 1989 the International Olympic Committee became the first to brand human growth hormone a banned substance. Although abuse of human growth hormone for athletic purposes is illegal in the U.S., over the past decade it appears that abuse of HGH is present in all levels of sport. full article available here:http://versita.metapress.com/content/b13g60325r532271/fulltext.pdf This is fueled at least in part by the fact that HGH is more difficult to detect than most other

performance-enhancing drugs Performance-enhancing substances, also known as performance-enhancing drugs (PEDs), are substances that are used to improve any form of activity performance in humans. A well-known example of cheating in sports involves doping in sport, where bann ...

, such as

anabolic steroids Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic androgens that are structurally related and have similar effects t ...

. This is because rHGH has an identical amino acid sequence to the native isoform of the hormone while GH from cadavers is indistinguishable from endogenous GH.

Athlete An athlete (also sportsman or sportswoman) is a person who competes in one or more sports that involve physical strength, speed, or endurance. Athletes may be professionals or amateurs. Most professional athletes have particularly well-develo ...

s competing in power sports, bodybuilding,

professional wrestling Professional wrestling is a form of theater that revolves around staged wrestling matches. The mock combat is performed in a ring similar to the kind used in boxing, and the dramatic aspects of pro wrestling may be performed both in the ring or ...

mixed martial arts Mixed martial arts (MMA), sometimes referred to as cage fighting, no holds barred (NHB), and ultimate fighting, and originally referred to as Vale Tudo is a full-contact combat sport based on strike (attack), striking, grappling and ground f ...

swimming Swimming is the self-propulsion of a person through water, or other liquid, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs and the body to achieve hydrodynamic thrust that r ...

, baseball, strength sports,

track and field Track and field is a sport that includes athletic contests based on running, jumping, and throwing skills. The name is derived from where the sport takes place, a running track and a grass field for the throwing and some of the jumping even ...

, cycling, soccer, weight lifting, skiing and endurance sports have been said to abuse human growth hormone, including in combination with other performance-enhancing drugs such as androgenic anabolic steroids including testosterone, certain products which claim to enhance HGH, and

erythropoietin Erythropoietin (; EPO), also known as erythropoetin, haematopoietin, or haemopoietin, is a glycoprotein cytokine secreted mainly by the kidneys in response to cellular hypoxia; it stimulates red blood cell production (erythropoiesis) in the bo ...

(among others). There has never been an adequately large

randomized controlled trial A randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical te ...

showing definitively that HGH provides benefits to athletes and that there are no significant

adverse drug reaction An adverse drug reaction (ADR) is a harmful, unintended result caused by taking medication. ADRs may occur following a single dose or prolonged administration of a drug or result from the combination of two or more drugs. The meaning of this term ...

s; there have been many small studies and several of these studies were recently reviewed and analyzed in a

meta-analysis A meta-analysis is a statistical analysis that combines the results of multiple scientific studies. Meta-analyses can be performed when there are multiple scientific studies addressing the same question, with each individual study reporting me ...

. While the authors indicated that the meta-analysis was limited by the fact that few of the included studies evaluated athletic performance and by the fact that dosing protocols in the studies may not reflect real-world doses and regimens, their conclusions were as follows:

"Claims that growth hormone enhances physical performance are not supported by the scientific literature. Although the limited available evidence suggests that growth hormone increases lean body mass, it may not improve strength; in addition, it may worsen exercise capacity and increase adverse events. More research is needed to conclusively determine the effects of growth hormone on athletic performance."

With regard to adverse drug reactions, there is data from animal studies that "long-term administration of human growth hormone can increase the risk of diabetes, retention of fluids, joint and muscle pain, hypertension, cardiomyopathy, osteoporosis, irregular menstruation, impotence and elevated HDL cholesterol." A report from the

United States House Committee on Oversight and Government Reform The Committee on Oversight and Reform is the main investigative committee of the United States House of Representatives. The committee's broad jurisdiction and legislative authority make it one of the most influential and powerful panels in the ...

steroid A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and ...

and growth hormone use found that the misguided use of HGH by professional athletes and entertainers was fuelling the industry peddling the drug to the general public for medically inappropriate uses.

Putative benefits

Lean body mass

Studies have found that HGH reduces body fat and increases lean body mass. However, no increase in muscle strength was observed. This may be explained by short-term fluid retention.

Muscle mass

Researchers are still debating whether the more noticeable muscles are larger in size as well. It should be clarified, though, that muscle mass is not the same as muscle strength. Some say that human growth hormone will build muscle mass through raised insulin-like growth factors levels leading to heightened

protein synthesis Protein biosynthesis (or protein synthesis) is a core biological process, occurring inside cells, balancing the loss of cellular proteins (via degradation or export) through the production of new proteins. Proteins perform a number of critical ...

without any side effects while other researchers argue that there have been no such findings on young healthy adults. The second argument is more supported by research discoveries that HGH affects muscle protein synthesis no differently than a

placebo A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like saline), sham surgery, and other procedures. In general, placebos can aff ...

does.

Injury resistance

HGH may build up connective tissue within muscles, at least in the short term. If these effects are real they "may promote resistance to injury or faster repair utwould make the muscle no more capable of force generation". With the release of the

Mitchell Report The ''Report to the Commissioner of Baseball of an Independent Investigation into the Illegal Use of Steroids and Other Performance Enhancing Substances by Players in Major League Baseball'', informally known as the Mitchell Report, is the res ...

on December 13, 2007, 86 players were revealed to have used performance-enhancing drugs while playing in the Major Leagues. The report stated: "Players who use Human Growth Hormone apparently believe that it assists their ability to recover from injuries and fatigue".

Drawbacks

Acromegaly patients, who suffer from natural growth hormone levels of up to 100 times higher than normal, have lower stamina towards physical activity than people with regular levels. When the patients are treated and their growth hormone levels decrease, their stamina improves. This knowledge is part of the evidence behind the new belief that athletes who use supplemental HGH to raise their levels far above average could actually decrease their exercise tolerance, and thus hurt their athletic performance. Further backing was provided in a study done by the Danish Institute of Sports Medicine. They found cyclists of good health and endurance "were unable to complete accustomed cycling tasks after administration of exogenous hGH" and concluded that HGH can inhibit recuperation from exercise. Participants have also been found to have lower stamina after HGH treatment along with higher rates of fatigue. Although adverse side effects can result from excessive doses, typical GH therapy has few side effects and those have likely been overstated due to the excessive amounts administered in earlier studies.

References

{{DEFAULTSORT:Hgh Treatment For Athletic Enhancement Drugs in sport Growth hormones