Human Growth Hormone: FAQ

jintropinThe New York Times recently published an article announcing a new anti-doping test for HGH. This gives us an opportunity to write a Q&A post, so that you’ll all be experts on HGH doping and HGH testing.

I’m half-serious, by the way. The quality of reporting on doping issues is so terrible, you can read this Q&A and you’ll know more about doping than 95% of the journalists who make a living writing about doping. (There are exceptions. I love you, Bonnie Ford!)

Q: What is HGH?

A: HGH is “human growth hormone”, a substance secreted by the pituitary gland that promotes growth in children and adolescents. HGH works by stimulating the body’s production of “insulin-like growth factor I” (IGF-1), and IGF-1 triggers the growth of bones and body tissues. This is well-known, basic, Wikipedia stuff.

Q: Why would an adult athlete want to take HGH?

A: Depending on who you believe, HGH may make adults bigger and stronger.

Q: You mean, HGH works like steroids?

A: Well, it’s not exactly clear. Some sources report that HGH works like anabolic steroids and testosterone to help build muscle. However, there’s no proof that HGH actually increases athletic performance.

Q: That doesn’t make sense. HGH MUST enhance athletic performance if it helps make you bigger.

A: That’s the strange thing. The studies seem to indicate that HGH might promote muscle gain, but HGH doesn’t seem to make you any stronger.

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Q: What? How could that be?

A: I don’t know. Maybe HGH just enables your muscles to retain a little more water.

Q: I remember Andy Pettite saying that he used HGH to help recover from an injury. Can HGH help an athlete heal?

A: Maybe. On this question, we simply have no definitive information one way or the other.. MLB is funding a scientific study to examine this question.

Q: The only answers you’re giving us are “maybe”, “could be” and “who knows”. C’mon. Give it to us straight. Do you figure that HGH is performance-enhancing or not?

A: I don’t know. But I figure not.

Q: But if HGH was worthless, then athletes wouldn’t use it.

A: This is the question. Do we believe the scientists, who say that HGH does not enhance performance, or the cheating athletes, who seem to think that HGH is helpful? To confuse matters, there are scientists out there who choose to believe the athletes and not their fellow scientists. But athletes can be scammed, same as anyone else. Remember the idea that you weren’t supposed to give football players water when they trained in the heat? Or that athletes weren’t supposed to have sex the night before a competition?

Q: Oh yeah. Those were some stupid ideas. But I’d think that if cheating athletes were using HGH and seeing no results, they would have given it up long ago.

A: Maybe. But from what I’ve read, cheating athletes don’t use HGH alone. They use HGH in combination with other performance-enhancing drugs, like steroids and insulin.

Q: I see. So if the athletes are seeing results, maybe the results are being produced by those other drugs.

A: Maybe. Or maybe HGH is effective when used in combination with other drugs.

Q: OK. Enough about the effects of HGH. Let’s talk about testing. Why is it so hard to catch athletes that are doping with HGH?

A: One reason is that HGH is a natural substance. We all produce HGH. We all have it in our bloodstream.

Q: Yes, but our HGH is natural. The HGH used by doping athletes is artificial.

A: ARTIFICIAL??? NEVER use the word “artificial” here, not ever again! The correct distinction is between exogenous HGH, stuff produced OUTSIDE the body, and endogenous HGH, stuff produced INSIDE the body.

Q: Can I say “synthetic”?

A: That’s a better word. But you can get “natural” HGH from cadavers, and that would still be cheating. It’s doping if the HGH is produced outside of the body, no matter how it’s produced.

Q: Geez. Why so touchy?

A: Because idiots in the media and on the blogosphere use words like “synthetic” and “artificial” to imply that there’s some difference between endogenous and exogenous HGH, like you could pluck a molecule of HGH out of a doper’s bloodstream, and hold it up to the light, and say, “that looks artificial to me.” HGH is HGH. The HGH produced in the lab is the real thing.

Q: You’re confusing me. If there’s no difference between artificial …

A: exogenous …

Q: Um, right, exogenous and endogenous HGH, if there’s no difference between the two, how can you devise a test to catch the athletes doping with HGH?

A: Well, like I said, a molecule of HGH is a molecule of HGH, no matter whether it’s exogenous or endogenous. But there might be a statistical difference between a population of exogenous HGH molecules and a population of endogenous HGH molecules.

Q: You’ve lost me.

A: Let’s say I have a bunch of yellow M&Ms in my pocket. Without your knowing it, I take my yellow M&Ms and put them into your bag of M&Ms. My yellow M&Ms are exogenous, because they come from outside of your bag. How can you tell that you have exogenous M&Ms in your bag? Well, you can’t tell by testing any single M&M – they’re all genuine M&Ms. But if you empty the entire bag and count the number of M&Ms of each color, you’ll notice that there are too many yellow M&Ms. The M&M candy people wouldn’t put so many yellow M&Ms in the same bag. There has to be some other explanation.

Q: Like M&M doping?

A: Stick with me here. HGH comes in different “isoforms”. For our purposes, an isoform is like a “color” of HGH. Most endogenous HGH comes in a single isoform – let’s say that this isoform is like the yellow M&Ms. But there’s a little bit of endogenous HGH that is produced in other isoforms – let’s say that these HGH isoforms are like red and green M&Ms. So you naturally have HGH in your blood in a mix of “colors”. Now we come to the key point. The scientists think that ALL exogenous HGH comes in a single isoform – the isoform that’s like the yellow M&Ms. If an athlete dopes with HGH, he’s going to have too much “yellow” HGH, and the anti-doping testers will know that something is up.

Q: And the anti-doping testers have a test to look at the mix of “colors” in an athlete’s HGH?

A: Yes.

Q: Great! How many dopers has this test caught so far?

A: So far, since 2004, one doper.

Q: One doper? Not so great.

A: That’s an understatement.

Q: Why haven’t more people been caught?

A: The leading doping expert in the U.S., Dr. Don Catlin, says that this HGH test is not a useful test. It’s hard to say why the test isn’t working. Maybe taking exogenous HGH doesn’t always make large changes in the mix of HGH “colors” in the blood. Or maybe there’s enough natural fluctuation in the HGH color mix, from person to person or from day to day, that it’s hard to distinguish a natural “color” fluctuation from an artificial “color” bump caused by doping.

Q: You just used the word “artificial”.

A: Try to stay focused here. Another reason why it’s hard to test for HGH doping is that doping produces only a short-term change in the mix of HGH “colors” in the blood. After a day or two, the mix of “colors” returns to normal.

Q: OK. What about the new test announced in the NY Times article?

A: The New York Times article does not provide us with much information about the new test. Actually, this doesn’t seem to be a new test. The test appears to be the same as one proposed at least as early as 1999. For some reason that’s not clear to me, the World Anti-Doping Association initially rejected this test in favor of the isoform test. I cannot say what is causing all of the new interest in this (relatively) old test.  [Here’s a recent IIATMS posting on the types of tests.]

Q: Great. The new test is not new. This discussion could not get any more confusing. But if the “new” test is not new, can we at least say that the “new” test is different?

A: Yes. The “new” test takes a different approach. It does not look at the HGH in an athlete’s blood. Instead, the test looks at a “biomarker” associated with HGH.

Q: I bet whatever question I want to ask now, you’ll want to tell us about biomarkers.

A: “Biomarker” is a term used broadly in medicine. Wikipedia says that a “biomarker” refers to “anything that can be used as an indicator of a particular disease state or some other biological state of an organism.” In anti-doping, a “biomarker” is usually some measurable body state that is affected by the taking of a performance-enhancing drug. So, an HGH biomarker test would measure something in the athlete’s body that would be affected by the taking of HGH.

Q: If I say I don’t understand, are you going to start talking about M&Ms again?

A: OK, here’s a simple example. I want to devise a test to determine whether you’ve been kicked in the shin. My test is that I’m going to examine your shin for a black-and-blue mark. If you have a black-and-blue mark, that could be a biomarker for a kick in the shin.

Q: Or that I closed the car door on my leg.

A: Let’s use a better example. Let’s say that you want to catch athletes who do blood doping. Blood doping is a way for an athlete to increase the number of red blood cells in his blood stream. Red blood cells carry oxygen, and certain athletes (particularly endurance athletes) will perform better with a higher number of red cells in their blood. Moreover, there’s no anti-doping test that can directly detect blood doping (at least, so long as the athlete blood dopes with his own blood). However, blood doping has an effect on certain biomarkers. For example, when an athlete blood dopes, the body reacts by producing fewer new red blood cells (new red blood cells are called “reticulocytes”). A low reticulocyte count can be a biomarker for blood doping.

Q: OK … so when you can’t detect the doping, you try instead to detect an effect of the doping?

A: Very good! That’s one reason to test for biomarkers. There can also be a timing advantage in testing for biomarkers. A performance-enhancing drug like HGH can disappear from the bloodstream very quickly, as we’ve already noted. But an HGH biomarker might persist for much longer, maybe for a week, maybe for two weeks. This gives the anti-doping folks a better chance to catch the dopers.

Q: Gee … if biomarker testing is so terrific, then why aren’t all anti-doping tests designed to look for biomarkers?

A: Remember that a biomarker test measures the effect that the performance-enhancing drug has on the biomarker. It’s possible that the same effect might be produced by something other than the performance-enhancing drug.

Q: Like my black-and-blue mark being caused by the car door.

A: Yes. Going back to our example of blood doping, we said that a low reticulocyte count might be a biomarker for blood doping. But there are other things that might cause a low reticulocyte count: for example, getting sick, or moving from a high to a low altitude. There’s also a certain natural variation in most biomarkers. In order for the HGH test to be valid, the scientists have to find a biomarker measurement that they can confidently link to HGH use – and only to HGH use.

Q: You mean, something other than HGH might affect the HGH biomarker?

A: Yes. For example, the biomarker might be affected by exercise.

Q: You can’t be serious.

A: Hopefully, the test can distinguish between an effect caused by exercise and an effect caused by doping.

Q: Can you tell us, what’s the biomarker that the scientists have found for HGH?

A: There may be more than one biomarker. It’s not clear from the New York Times article. But the primary biomarker appears to be IGF-1, the stuff we talked about in the beginning of this Q&A.

Q: You mean, the same stuff you said that anyone could find out about by reading Wikipedia? What’s taken the scientists so long to focus on this biomarker?

A: I’m asking myself the same question. These guys were asking this question two years ago.

Q: Do you think baseball should be testing for HGH, using the new biomarker test?

A: First we need to make certain that the test works well enough to be effective. Doping tests are supposed to go through extensive validation. The other big issue is that the HGH marker test appears to be a blood test. Baseball performs doping tests on urine samples taken from players, but the players have resisted blood testing.

Q: But you said in the beginning of this Q&A that HGH does not appear to be performance-enhancing? If HGH is not performance-enhancing, then why should baseball spend so much time and money testing for HGH?

A: That’s a tough question, one that we’ll try to explore in later posts. It seems that when it comes to anti-doping, perception is more important than reality. The players perceive that HGH is performance-enhancing. The fans perceive that HGH is performance-enhancing. The anti-doping forces believe that they have a foolproof test to catch the athletes using HGH. IN ALL LIKELIHOOD, NONE OF THESE PERCEPTIONS ARE TRUE. Yet the perceptions takes on lives of their own. It seems likely that baseball WILL go forward with some kind of HGH testing. The only question is when.

Q: One last questions for you. You talk a lot of smack for a non-expert. Why should I believe you?

A: Because unlike the NY Times, I cite sources. Click through to any of the references I’ve given you here.

About the Author

Jason Rosenberg began his blogging career in late 2007 at his own baseball-focused blog, ItsAboutTheMoney, Stupid.

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