Written by Dan Gwartney, MD
09 April 2007
It's amazing to monitor medical conferences and publications, as literally hundreds, if not thousands, of new articles and abstracts are published monthly. By design, these articles should provide newsworthy research and reviews to expand the existing knowledge base. Researchers have been focusing on new means of combating one of America's greatest health challenges, obesity. Previously, obesity was treated using stimulants; later, appetite suppressants were developed. Both of these categories became associated with serious side effects, with the Phen-Fen crisis the most widely publicized.

Current therapies attempt to decrease calorie intake by interfering with food digestion or nutrient absorption. These methods have disadvantages as well, so the demand for further obesity research continues.

Bodybuilders Ahead of Science
Interestingly, researchers are now investigating some of the techniques that have been used by bodybuilders for decades. In addition to the obvious role of diet and exercise, some of the bodybuilders' trade secrets currently being studied or promoted include the use of resistance training to maintain muscle mass, low-carbohydrate diets, stimulant drugs and hormones. Sadly, much of this knowledge has been available for years, but because of the stigma attached to performance drug use, it has been ignored.

Medical ethics has turned away from promising research before. During the World War II, Nazi Germany had unethical scientists who performed tortuous research on prisoners; research was also conducted upon the country's own soldiers who were exposed to potentially harmful drugs. The resulting knowledge gained from this research program was never released, as the international community judged the Nazi research program to represent a war crime, rather than legitimate and ethical scientific research.1

Research such as this has occurred in other countries, including the United States (Tuskogee syphyllis), causing professional societies and governments to create ethical guidelines for acceptable scientific research.2 When information is gained in a manner that is suspect or places the subjects studied at significant risk, it's not considered acceptable for publication or distribution. The use of steroids and other drugs by athletes and bodybuilders is considered unacceptable as the unsupervised use of these drugs carries a great risk of adverse side effects.

Bodybuilders have long used growth hormone as both an anabolic aid and to promote fat loss.3-5 Initially, growth hormone was dosed at the same strength used to promote growth in children who failed to grow normally. When dosed at one IU per kilogram body weight per week, growth hormone caused a number of adverse side effects in bodybuilders, though it was remarkably effective at increasing muscle size. Bodybuilders began to experience the commonly reported side effects of organ growth, facial distortion and abnormal bony growth, edema, carpal tunnel syndrome, diabetes and a greater incidence of gynecomastia.3,6,7 In addition to the physical consequences associated with the excessive doses, the financial cost could be astronomical.5

Lower Doses Do It
Later, it was discovered that the fat reducing effects of growth hormone could be obtained using much lower doses. Clinical studies have demonstrated that a lower dose was as effective in fat loss, with less risk of side effects.8-10 Building upon this data, researchers at the St. Louis University Department of Endocrinology investigated the use of growth hormone in reducing body fat in a group of obese adults.

Presented at ENDO 2003, the annual meeting of the Endocrine Society, the study confirmed that low doses of growth hormone improve the fat loss effects of diet and exercise.11 Dr. Albert's team treated two groups in a placebo-controlled, double blind study. The subjects were obese adults who were provided with diet guidelines designed to create a 500-calorie per day deficit. An exercise program was also provided. At the conclusion of the six-month study, the group receiving daily injections of growth hormone (200 to 400 micrograms per day, approximately one IU) lost five pounds compared to the control group, whose weight remained stable. Interestingly, all the weight lost by the growth hormone-treated group was body fat, predominantly from the abdominal area.

This study, which has not yet been published, is interesting and supports the current understanding that growth hormone can reduce body fat. However, a closer examination of the details reported thus far is even more intriguing. The study was presented as an abstract, which has the disadvantage of an absence of detail. It's unclear as to whether the diet and exercise were monitored, either through direct observation or training logs and food diaries. It's difficult to believe there was an acceptable level of compliance, meaning the subjects followed the directions provided and adjusted their diets and lifestyles. Six months of a hypocaloric diet, in conjunction with exercise, should have resulted in modest fat reduction and weight loss. However, despite being instructed to follow a diet and exercise program that should have resulted in approximately one pound per week weight loss, the control group's weight and body composition remained the same.

This suggests that the subjects were not diligent in following the diet and exercise. Yet, despite the suggested sloth of the subjects, growth hormone treatment still resulted in significant fat loss. Not only did the subjects lose over five pounds of fat, there was also an increase in HDL cholesterol, known as the good cholesterol.5,11 The reported benefits of low-dose growth hormone treatment for fat reduction are a strong argument for instituting the use of growth hormone in combating obesity. However, to take the argument one step further, is it a suitable argument for the use of growth hormone cosmetically, such as reducing body fat in healthy people like bodybuilders?

    Fat for Energy vs. Storage
Albert reported that he was uncertain of the mechanism by which growth hormone reduced body fat in his treated subjects. It has been shown that growth hormone is a potent lipolytic hormone, acting directly on the fat cell.12-14 Though growth hormone is best known as an anabolic hormone, it's a strong signal when interacting with receptors on the fat cell membrane.

Under the influence of growth hormone, an enzyme (hormone sensitive lipase) is activated, releasing free fatty acids from stored triglycerides.12,14 This is an important first step in reducing body fat. Dietary fat is commonly consumed in the form of triglycerides, which is a group of three fatty acids joined to one glycerol molecule. In order to be absorbed by the body and then incorporated into fat cells for storage, it must be broken down to the individual fatty acids by digestive enzymes. These free fatty acids are then taken through the bloodstream and enter the fat cell where they are re-attached to glycerol to form a new triglyceride. As a triglyceride, the fat remains in the fat cell and cannot be used for energy.

Under the influence of certain hormones and neurotransmitters, such as growth hormone and epinephrine, enzymes in the fat cell break down triglycerides and release the stored fat as free fatty acids, which can then be used for energy.12,14 It's likely that growth hormone's greatest fat loss benefit is based on the liberation of stored fat. The use of growth hormone in low doses (one to two IU per day), can be a potent aid to promoting fat loss and improving health, particularly among the obese. Obese people are known to have lower growth hormone levels than normal weight individuals and when supplemented with growth hormone, they lose significant amounts of body fat without any reported negative side effects.8,9,12   

The question that stands unanswered: Is it right to provide treatment to a population at risk due to lifestyle (overeating, sedentary habits) to combat the condition of obesity, yet restrict healthy adults from a tool that could provide optimal health, beyond what can be obtained through a rigorous and disciplined lifestyle? That is a matter of legislation and debate. The fact that medicine and science are turning to many of the tools of bodybuilding to combat obesity, HIV-associated wasting and other conditions, makes it clear there is value in studying the techniques that have been honed over decades of practical use.

It is hazardous for bodybuilders to self-medicate and most of the adverse effects contributed to bodybuilding drug use stem from uneducated abuse, underlying psychological conditions or adulterated, counterfeit products. Further, it's clear that society can benefit from the lessons learned in the trenches by bodybuilders. Perhaps in the coming years, legislation will be enacted that will allow bodybuilders and scientists to work together to develop promising new treatments for many of the conditions facing society today. It has already taken place with the anti-aging movement, so the concept is not as far-fetched as it seems.

References 
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2.    Dowd SB, Wilson B. Informed patient consent: a historical perspective. Radiol Technol 1995 Nov-Dec;67(2):119-24.
3.    Llewellyn W. Human Growth Hormone. Anabolics 2002, Molecular Nutrition Press, Patchogue, NY;2002:101-4.
4.    Florini JR, Ewton DZ, et al. Growth hormone and the insulin-like growth factor system in myogenesis. Endocr Rev 1996 Oct;17(5):481-517.
5.    Svensson J, Fowelin J, et al. Effects of seven years of GH-replacement therapy on insulin sensitivity in GH-deficient adults. J Clin Endocrinol Metab 2002 May;87(5):2121-7.
6.    Thompson JL, Butterfield GE, et al. Effects of human growth hormone, insulin-like growth factor 1, and diet and exercise on body composition of obese postmenopausal women. J Clin Endocrinol Metab 1998 May;83(5):1477-84.
7.    Ahmad AM, Hopkins MT, et al. Body composition and quality of life in adults with growth hormone deficiency: effects of low-dose growth hormone replacement. Clin Endocrinol (Oxf) 2001 Jun;54(6):709-17.
8.    Veldhuis JD, Iranmanesh A. Physiological regulation of the human growth hormone (GH)-insulin-like growth factor type I (IGF-1) axis: predominant impact of age, obesity, gonadal function, and sleep. Sleep 1996 Dec;19(10 Suppl):S221-4.
9.    Kim KR, Nam SY, et al. Low-dose growth hormone treatment with diet restriction accelerates body fat loss, exerts anabolic effect and improves growth hormone secretory dysfunction in obese adults. Horm Res1999;51(2):78-84.
10.    Taaffe DR, Thompson JL, et al. Recombinant human growth hormone, but not insulin-like growth factor-1, enhances central fat loss in postmenopausal women undergoing a diet and exercise program. Horm Metab Res 2001 Mar;33(3):156-62.
11.    Albert S. Presentation of data at ENDO 2003. Notes provided courtesy of Nancy Solomon of Saint Louis University media relations. Received July 8, 2003.
12.    Nam SY, Marcus C. Growth hormone and adipocyte function in obesity. Horm Res 2000;53 Suppl 1:87-97.
13.    Heffernan MA, Jiang WJ, et al. Effects of oral administration of a synthetic fragment of human growth hormone on lipid metabolism. Am J Physiol Endocrinol Metab 2000 Sep;279;(3):E501-7.
14.    Malmlof K, Johansen T. Growth hormone-mediated breakdown of body fat: Insulin and leptin responses to GH are modulated by diet composition and caloric intake in old rats. Horm Metab Res 2003 Apr;35(4):236-42.
15.    Hansen TK. Pharmacokinetics and acute lipolytic actions of growth hormone. Impact of age, body composition, binding proteins, and other hormones. Growth Horm IGF Res 2002 Oct;12(5):342-58.