Being tall may not seem like a big problem to most teen boys, but in Europe a few still choose to have their growth stunted by hormone injections.
A Dutch study now shows the treatment, involving testosterone injections, might have some unforeseen effects when these boys become men.
"We saw some interesting effects on testosterone levels later in life," said Dr Emile Hendriks of the Erasmus Medical Centre in Rotterdam. "The good news is it doesn't seem to affect fatherhood or fertility in these men."
In 2004, the more common practice of stunting girls using oestrogen came under scrutiny as it turned out to cause fertility problems, and researchers had worried that this might be the case for men as well.
Pushing puberty faster
The Dutch doctors tested 60 men 20 years after they had received high-dose testosterone injections, which stunts growth by pushing the youngsters through puberty faster.
The study was funded in part by Ferring Pharmaceuticals, which makes testosterone products.
The Dutch men, who stood nearly 6 feet 5 inches on average, turned out to be just as fertile as other tall Dutch men in their 30s.
Of those who had tried to have kids, more than seven in 10 had succeeded within a year in both treated men and an untreated comparison group.
Testosterone levels still normal
But their testosterone levels were markedly lower, although within the range considered normal.
"These men wouldn't have clinical signs," said Hendriks, adding that very low testosterone levels have been tied to frailty and sexual problems.
But testosterone levels dwindle naturally with age, suggesting that the men could experience some problems down the road.
"The nest interesting step would be to see what happen when the testosterone gets really low," Hendriks said.
Today, he said, stunting treatment is becoming less common in Europe. He estimates that in the Netherlands, only between 10 and 100 boys per year get the injections, which cost about $800 (about R5,400) in total.
That's nothing compared to the more popular growth hormone therapy, which boosts height in short boys and is also used in the US.
Researchers say prices run as high as $22,000 (about R154,000)a year, and with 500,000 American children meeting official criteria for the treatment, the drug has a potential market in excess of $10 billion(about R70 billion).
Dr Paul Saenger, a paediatrics professor at the Albert Einstein College of Medicine in New York City, said the Dutch study was important news for those who still use the treatment in perfectly healthy teens.
He noted that the treatment is not approved by the US Food and Drug Administration for stunting growth.
"What it means to me is that the treatment is flawed because people get problems later," he said. "The only problem if you are too tall is you can't become a jockey."
But the findings, published in the Journal of Clinical Endocrinology & Metabolism, are less relevant in the US, Saenger noted.
"I have never treated a man for tall stature in 30 years," he said. "You will never see a paper like this coming out of the US because we have basketball."
Susan Cohen, a journalist and the author of Normal at Any Cost, said that oestrogen treatment to stunt growth in girls was more common.
"There is much more social or cultural impetus to do that, although even that practice has diminished a lot because tall women are no longer considered condemned to a life without marriage or prospect," she said.
It is unclear exactly how high-dose testosterone injections in teenage boys can impact levels of the hormone 20 years later. One possibility is that they curb the development of testosterone-producing cells in the testicles.
(Reuters Health, Frederik Joelving, October 2010)