Pig Hormone Doesn't Help Autism
But researchers suspect brain-gut link in disorder
WEDNESDAY, May 9 (HealthScout) -- Many parents of autistic children got excited when they heard anecdotal reports that a pig hormone may help the disorder. But their hopes have once again been dashed by a new study that says the treatment doesn't work.
However, the researchers say this cloud may have a silver lining because the finding could point scientists in a new direction.
Hopes for autistic children were raised by TV news reports of a small study from the University of Maryland that described how injections of a digestive hormone, called secretin, from pigs seemed to make autistic children more talkative and interactive. But a randomized, double-blind study in the May issue of Pediatrics says while parents of kids injected with secretin and a placebo saw gains, objective tests of the kids revealed no improvements.
On the other hand, researchers say the original study pointed out that a disproportionate number of kids with autism also have stomach problems, and researchers now wonder whether there's a link between problems in the brain and problems in the stomach. Interest in the secretin began when parents seeking help for their autistic children's stomach problems saw improvements after the kids were injected with the hormone. Secretin, which helps the pancreas digest food, has been approved to treat gastrointestinal disorders.
"People were so incredibly hyped up, hoping to see major improvements," says Dr. Wendy Roberts, a developmental pediatrician who directs the Child Development Centre at the Hospital for Sick Children in Toronto and lead author of the latest study. "But I'm hoping that some of what we're seeing with the brain-gut connection will really make a difference."
About 500,000 Americans suffer from autism, an illness that usually begins before age 3 and is characterized by emotional withdrawal. Autistic children are less able to communicate and interact with others.
Several studies have been conducted in autistic children in the last few years to test the anecdotal claims about secretin, Roberts says. None have shown that secretin is effective. The latest study sought to plug some holes in other studies, she says.
The secretin in the new study was from pigs, unlike the synthetic version used in some trials. Sixty-four children were given two doses of the hormone, and they weren't examined until three weeks after each injection to give it time to work. The children also were divided into subgroups to see if any group was affected by secretin: those with higher IQs, those with stomach problems and those whose autism had first appeared when they were aged 18 months or older. But secretin did not make a significant difference for any of the subgroups, she says.
'Something different about the gut'
"Some of the parents who were most adamant that there had been improvements were those whose children turned out to have been given placebo," Roberts says.
In addition, secretin produced some serious side effects in about 10 percent of the children, making them quite irritable and hyperactive, Roberts says. One family even withdrew from the study because the problem was so severe.
But the study reinforced a sense among researchers that the relationship between autism and stomach problems needs to be explored further, Roberts says. About 39 percent of children with autism have diarrhea or reflux or other digestive problems, compared with about 15 percent in the general population.
"There's something different about the gut. It could well be something that's important," Roberts says.
Parents of children with autism are happy that serious research is finally addressing the illness, says Clarence Schutt, chairman of the board for the National Alliance for Autism Research and professor of chemistry at Princeton University in New Jersey. Schutt's 15-year-old son, Alex, is autistic. For many years, Schutt says neurobiology was pretty elementary, and autism was a complete mystery.
"It was too baffling. There was just no way to think about it in biomedical terms," Schutt says. "The real message in something like this study is a lot of us parents are grateful nowadays that these various leads are being taken up by serious and responsible researchers."
In addition to the brain-gut connection, Schutt says researchers are interested in how the Human Genome Project can help autism research. Roberts says no other medical solutions for autism are being seriously researched that she knows of; for now, intensive behavioral and language intervention are most successful.
What To Do
For more on autism, try the National Alliance for Autism Research. The Society for the Autistically Handicapped has links to articles on secretin and autism, including a comprehensive piece by a medical writer whose son has autism.
Click on other HealthScout articles about autism.