Study on hgh part 1

[hazcat]

March 21, 2008 — Growth hormone use increased lean body mass but not physical performance and was associated with adverse events, according to a systematic review in the March 18 Early Release issue of the Annals of Internal Medicine and will appear in the May 20 print issue of the Annals.

"Human growth hormone is reportedly used to enhance athletic performance, although its safety and efficacy for this purpose are poorly understood," write Hau Liu, MD, MBA, MPH, and colleagues from Santa Clara Valley Medical Center in San Jose, California; Stanford University in Stanford, California; and the Veterans Affairs Palo Alto Health Care System in Palo Alto, California. "This practice, often called sports doping, is banned by most professional sports leagues and associations, including the International Olympic Committee, Major League Baseball, and the National Football League. However, a wide range of athletes, including those from baseball, cycling, and track and field, have been implicated in or confessed to illicit growth hormone use."

The objective of this systematic review was to examine evidence concerning the effects of growth hormone on athletic performance in physically fit, young individuals. A search of MEDLINE, EMBASE, SPORTDiscus, and Cochrane Collaboration databases for English-language studies published between January 1966 and October 2007 identified randomized controlled trials comparing growth hormone treatment with no growth hormone treatment in community-dwelling healthy participants aged 13 to 45 years. Two authors independently reviewed the identified articles and abstracted data.

A total of 44 articles met inclusion criteria. These articles described 27 study samples in which a total of 303 participants received growth hormone, representing 13.3 person-years of treatment. Participants were young (mean age, 27 ± 3 years), lean (mean body mass index [BMI], 24 ± 2 kg/m2), and physically fit (maximum oxygen uptake, 51 ± 8 mL/kg of body weight per minute).

The identified studies varied in growth hormone dosage (mean, 36 ± 21 µg/kg per day) and treatment duration (mean, 20 ± 18 days) for studies giving growth hormone for more than 1 day. Compared with participants who did not receive growth hormone, those who did had increased lean body mass (mean increase, 2.1 kg; 95% confidence interval [CI], 1.3 - 2.9 kg), but strength and exercise capacity did not appear to improve.

In 2 of 3 studies that evaluated lactate levels during exercise, these were statistically significantly higher in growth hormone recipients. Soft tissue edema and fatigue were more frequently reported in growth hormone–treated participants vs those not treated with growth hormone.

Limitations of the review include few studies that evaluated athletic performance, and growth hormone protocols in the studies may not reflect real-world doses and regimens.

"Claims that growth hormone enhances physical performance are not supported by the scientific literature," the review authors write. "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."

The Agency for Healthcare Research and Quality, the Department of Veteran Affairs, Stanford University Medical Center, Stanford University, Genentech, Inc, the National Science Foundation, and the Evidence-Based Medicine Center of Excellence of Pfizer supported this study. Some of the review authors have disclosed various financial relationships with Blue Cross and Blue Shield Association, Genentech, Teva, LG Life Sciences, Ambrx, and the US Attorney (expert testimony regarding off-label use of growth hormone).

Ann Intern Med. Published online March 18, 2008.

Learning Objectives for This Educational Activity
Upon completion of this activity, participants will be able to:
Describe the effect of growth hormone on lean muscle mass and physical performance, based on a meta-analysis.
Describe adverse events associated with use of growth hormone.
Clinical Context
Although sports doping, or the use of human growth hormone to improve athletic performance, is banned by most professional sports leagues and associations, athletes involved in several different sports have been implicated in illicit use of growth hormone. Athletes reportedly use growth hormone to enhance athletic performance, but its efficacy for this purpose is still unclear.

In growth hormone–deficient adults, and possibly in healthy elderly adults, administration of growth hormone results in increased lean mass and decreased fat mass. Recent evidence and opinion suggests that for healthy adults, the strength-enhancing properties of growth hormone have been exaggerated. Serious adverse effects associated with use of high-dose growth hormone in athletes may include diabetes, hepatitis, and acute renal failure. The use of growth hormone for athletic enhancement is not approved by the US Food and Drug Administration, and distribution for this purpose is illegal in the United States.

Study Highlights
The purpose of this systematic review was to determine the effects of growth hormone therapy on athletic performance in healthy, physically fit young adults.
The primary goal was to assess the effects of growth hormone on body composition, strength, basal metabolism, and exercise capacity, and the secondary aim was to summarize evidence on adverse events associated with use of growth hormone in healthy, physically fit young adolescents and adults.
The reviewers searched MEDLINE, EMBASE, SPORTDiscus, and Cochrane Collaboration databases for English-language studies published between January 1966 and October 2007.
Inclusion criteria were randomized controlled trials comparing growth hormone treatment with no growth hormone treatment in community-dwelling, healthy participants aged 13 to 45 years.
2 authors independently reviewed the identified articles and abstracted data.
44 articles met inclusion criteria, describing 27 study samples in which a total of 303 participants received growth hormone, representing 13.3 person-years of treatment.
Mean age of participants was 27 ± 3 years, and mean BMI was 24 ± 2 kg/m2.
Participants were physically fit, with mean maximal oxygen uptake of 51 ± 8 mL/kg of body weight per minute.
The identified studies varied in growth hormone dosage (mean, 36 ± 21 µg/kg per day) and treatment duration (mean, 20 ± 18 days) for studies giving growth hormone for more than 1 day.
Compared with participants who did not receive growth hormone, those who did had increased lean body mass (mean increase, 2.1 kg; 95% CI, 1.3 - 2.9 kg) and a near-significant trend toward decreased fat mass.
Use of growth hormone had a minimal effect on key athletic performance outcomes such as gains in biceps and quadriceps strength and exercise capacity, and it may even be associated with worsened exercise capacity.
Growth hormone therapy resulted in increased use of lipids for fuel during rest, reflected in a statistically significantly lower resting respiratory exchange ratio and respiratory quotient. However, this improvement did not appear to persist during exercise.
In 2 of 3 studies that evaluated lactate levels during exercise, these were statistically significantly higher in growth hormone recipients. Increased lactate levels during exercise are associated with decreased exercise stamina and physical exhaustion.
Soft tissue edema, joint pain, carpal tunnel syndrome, and fatigue were more frequently reported in growth hormone–treated participants vs those not treated with growth hormone. These adverse events may be related to fluid retention.
Limitations of the review include few studies that evaluated athletic performance, growth hormone protocols in the studies may not reflect real-world doses and regimens, no studies evaluated growth hormone for periods longer than 3 months, and only a small percentage of participants were women.
Based on these findings, the reviewers concluded that claims that growth hormone enhances physical performance are not supported by the scientific literature; limited available evidence suggests that growth hormone increases lean body mass, but it may not improve strength and may actually worsen exercise capacity and increase adverse events.
The reviewers recommend more research to conclusively determine the effects of growth hormone on athletic performance.
Pearls for Practice
A systematic review suggests that claims that growth hormone enhances physical performance are not supported by the scientific literature. Limited available evidence suggests that growth hormone increases lean body mass, but it may not improve strength and may actually worsen exercise capacity.
In 2 of 3 studies that evaluated lactate levels during exercise, these were statistically significantly higher in growth hormone recipients. Soft tissue edema, joint pain, carpal tunnel syndrome, and fatigue were more frequently reported in growth hormone–treated participants vs those not treated with growth hormone. These adverse events may be related to fluid retention.

[dashizzle]

great post.
Thanks

[access]

This seems to be the most pertinent sentence in the whole "study":

Limitations of the review include few studies that evaluated athletic performance, and growth hormone protocols in the studies may not reflect real-world doses and regimens.

[hazcat]

Don't you love the disclaimers? It was actually something recent that just came out this month. I like timely info instead of an article people post up from decades ago. I see those time and again and think...hmmmm I wonder how many newer studies show the older study to be obsolete and without merit.

[MuscleScience]

Its not really a disclaimer, the limitations section acknowledges the weakness of the study. It is also used to get additional funding to run new studies.

But yeah it does to make some very bold claims for the limitations the authors listed.

[Adam F]

Good post Haz

[pumbertot]

coincidence or not that this appears just ahead of the Olympics? has me wondering.....

also what they fail to mention or what is obvious to me are a few things.
firstly the dosages and length of HGH courses appear less than us athletes use.
secondly when you are near the limit of your genetic potential, unlike the participants of any study examined, HGH appears to give you something extra. thats why we use it, thats why top athletes in track and field use it etc, that extra edge when you are near full capacity.

.....just my 10 cents worth of course.

[MuscleScience]

I read over the the study a little better at the online site for the journal that it was published in and I have a few rebuttals.

1. It was a review article so the author had never actually done any trials himself he just looked at the present data and came up with the conclusion as stated.

2. They didnt look at studies any longer than three months, this is a standard durations for exercise studies in humans. However athletes by there own admission use it longer than three months.

3. While its true that HGH may decrease lactate threshold capacity in endurance athletes lactate thresholds are only important in endurance athletes. HGH would not be used to a great extent by endurance athletes because it decrease the uptake of glucose by fat and muscle cells. Hence why lipids are used as a fuel source at rest, and are decreased during intense exercise.

4. Even thought the author says the evidence doesnt conclusively show that HGH improves athletic performance by their measure, it also doesnt disprove it as well which is something that they should have made it a point to put out as well. Or better yet they should have said the data was inconclusive either way.

Just my critical review of this article as a skeptic.

[access]

All very valid points MuscleScience and why you need to read between the lines sometimes on these studies.