Growth Hormone Overrated in Athletic Gains: Study

March 17, 2008— -- NEW YORK (AP) - Athletes who take human growth hormone may notbe getting the boost they expected.

While growth hormone adds some muscle, it doesn't appear toimprove strength or exercise capacity, according to a review ofstudies that tested the hormone in mostly athletic young men.

"It doesn't look like it helps and there's a hint of evidenceit may worsen athletic performance," said Dr. Hau Liu, of SantaClara Valley Medical Center in San Jose, Calif., who was leadauthor of the review.

Growth hormone, or HGH, is among the performance enhancersbaseball stars Roger Clemens and Andy Pettitte were accused oftaking in the blockbuster Mitchell Report. Clemens denies using thehormone, while Pettitte admits using it.

But the new research has some limitations and sheds no light onlong-term use of HGH. The scientists note their analysis includedfew studies that measured performance. The tests also probablydon't reflect the dose and frequency practiced by athletesillegally using the hormone. Experiments like that aren't likely tobe conducted.

"It's dangerous, unethical and it's never going to be done,"said Dr. Gary I. Wadler, a member of the World Anti-Doping Agencyand a spokesman for the American College of Sports Medicine.

Consequently, those in the field have to depend on such reviewsor "what we hear on the ground," he added.

Human growth hormone is made by the pituitary gland and promotesgrowth. A synthetic version has been available since the 1980s andits use is restricted for certain conditions in children andadults, including short stature, growth hormone deficiency andwasting from AIDS.

Although banned for other uses, growth hormone has been used bya variety of athletes and was cited along with steroids as one ofthe performance-enhancing drugs abused by baseball players in thereport in December by former Senate majority leader GeorgeMitchell. Several athletes, including Pettitte, have said they usedHGH while recovering from an injury, an issue not covered in thereview.