For Very Short Child, Should Parents Consider Growth Hormone Therapy?

Erica Nicholson knew that her son, Sam, was small. Considering that she was barely 5 feet and 100 pounds and that his older sister was a "peanut," it didn't seem unusual.

"I make small babies," Nicholson said. But her daughter was growing. Sam, however, was so small that he looked like a baby compared with his peers, she said. When he was 4, his feet did not touch the ground on a training bike his sister had used at the same age.

A pediatric endocrinologist determined that Sam had celiac disease, an autoimmune disorder that inhibits nutrient absorption. Switched to a gluten-free diet, he grew an inch in a month. But his growth rate was still slow. Doctors predicted he would be no taller than 4-foot-7 as an adult.

Nicholson set out on a search for answers, going from "one scary diagnosis to another," she said, eventually finding success with growth hormone, a costly and controversial treatment.

Parents of short boys are thought to be more likely to take such action than those of short girls. Some note that short girls may be socially accepted and called cute while short boys face teasing and possible disadvantage. Others, such as Nicholson, worry that something is just not right.

Tests ruled out a rare genetic disorder, Russell-Silver syndrome, as well as a form of dwarfism and growth hormone deficiency, a condition in which the pituitary gland does not produce enough of the hormone needed for tissue growth.

Finally, when he was 5, a doctor determined that Sam had idiopathic short stature, or ISS, which means that no reason for his poor growth had been found.

Sam started growth hormone treatment two years ago. Now 7, he has grown eight inches. "He is in the 8th percent on the growth chart," Nicholson said. "You're happy to have that."

Short stature is a not a disease, said Laurie Cohen, clinical chief of endocrinology at Boston Children's Hospital. But the further outside the normal range a child is on the grid that physicians use to monitor height and weight, the more likely "something else is going on," Cohen said.

Use of growth hormone for ISS is controversial because of concern that it might introduce risks to a short but otherwise healthy child.

The problem, particularly for insurers, is distinguishing between disease and normal variation and "where do things fall on a priority list of medical expenditures," said David Allen, a pediatric endocrinologist at American Family Children's Hospital in Madison, Wisconsin.

Debate arose in 1985 when synthetic human growth hormone (GH) began to be produced, greatly increasing the supply of the hormone. In 2003, the Food and Drug Administration approved GH for children who were not deficient in growth hormone but who were short in stature and slow to grow. The pool of potential candidates for treatment grew to 1 in every 100 children. While girls and boys are equally represented in this group, most who are referred and treated for ISS are boys.

A French study had suggested an increased risk of death associated with GH, but in a 2011 statement the FDA called that study inconclusive. Still, guidelines for pediatric endocrinologists - the doctors who treat short children - say patients should be informed about "the uncertainty regarding long-term safety (posttreatment adverse effects in adulthood)."

"A lot of assumptions that were driving growth hormone as treatment for shortness have been difficult to prove," Allen said. Weighing the possible long-term risks against uncertain benefits - growth hormone does not work on all children and there is little evidence showing a relationship between height and psychosocial outcomes - makes the field challenging.

And insurance companies often are unwilling to pay for treatment.

Tests for GH deficiency are subjective and can be inaccurate, experts note, and may not explain the bigger picture.

"It's not how these kids are categorized, it's the severity of their disability. That's the one thing I think we're struggling with," said Allen. It's difficult for insurers to sort out who needs treatment from those who don't, he said.

Adults with severe shortness (less than 63 inches for men and 59 inches for women) may face difficulties with everyday tasks such as driving a car. Growth hormone treatment can help not only with such problems but also with bone density, energy metabolism and cardiovascular health, said Kupper A. Wintergerst, professor of pediatrics at the University of Louisville and chief of endocrinology and diabetes at Norton's Children's Hospital.

Nicholson has appealed for coverage for her son and been denied three times. The family pays $550 a month for Sam's medication. The price will increase as the dose increases, possibly to $1,200 a month as he nears puberty, she said. By some estimates, the cost of treatment is roughly $52,000 an inch.

The long haul is worth it, Nicholson said. Her son looks more like his peers and has the muscle strength to ride his bike. And while their endocrinologist will not predict a final adult height, "we know he won't be 5-3," she said. The goal is at least 5-foot-7.

While the short-term risks of growth hormone are known and relatively rare - intracranial hypertension, worsening scoliosis and Type 2 diabetes - there is little long-term data on adults, Cohen said.

Because of the role growth hormone plays in tumors and making cells grow, "there have always been theoretical risks of malignancy," she said.

Every week in her clinic at the University of Iowa Stead Family Children's Hospital, pediatric endocrinologist Vanessa Curtis sees middle-school-age patients. It's a common time for families to seek evaluation, especially for boys who may have inherited short stature and have not yet hit their puberty-related growth spurt.

But there is also gender bias, according to pediatric endocrinologist Adda Grimberg, scientific director of the growth center at Children's Hospital of Philadelphia. This bias leaves some girls with underlying disease untreated and produces "over-zealous treatment of healthy short boys with an expensive medication," she concluded in a study published in 2015.

For Curtis, a priority with late-to-bloom boys is to make sure they are healthy and growing appropriately based on medical and family histories. Sometimes she will recommend watchful waiting or a gradual course of testosterone to kick-start puberty.

Some families are interested in GH therapy to give the child a competitive advantage in sports.

"I don't care if you're a millionaire - there are a lot better things you can do with your money for $50,000. You could hire a pretty awesome coach or go to some great camps," Curtis said. "If a family is asking that I prescribe GH who doesn't meet the criteria (and) just wants them to be bigger, faster, stronger, I would not feel comfortable doing that."

Genetic research and gene sequencing, while expensive, may help find the causes of ISS and identify who will respond to treatment.

Joel Hirschhorn, a professor of genetics at Boston's Children's Hospital and leader of GIANT, an international consortium that has uncovered the genes that influence height, said gene sequencing may also reassure parents that "there's nothing else going on."

In uncovering more genes, idiopathic cases gain explanations and should become less common.

One of the most emotional issues regarding treatment is the role that height plays in our cultural beliefs about success and happiness.

David Sandberg, a pediatric psychologist at the University of Michigan's C.S. Mott Children's Hospital, who has spent 18 years looking at the psychosocial aspects of short stature, said there are very strong stereotypes associated with height, some based on outdated preferences explained by anthropology.

At one point in our evolution, height was an important a feature of attractiveness because it was a sign of good nutrition and physical health, Sandberg said. While height is no longer such a strong indicator in Western societies, "the beliefs about the disadvantages of being short are so powerful that no evidence is going to counter that."

Sandberg's research shows that the stereotypes about the disadvantages of being short do not hold up. In a seminal study, he investigated whether height was a strong predictor of social adjustment for children in grades 6 to 12 in a suburban school district. In one exercise, students were asked to cast peers in a class play for roles portraying various characters, including some described as "good leader" and a person who "has many friends," as well as one who "is often left out."

There was only one role where short kids were disproportionately nominated, he said: "Looks younger than they are."

In a separate study, Sandberg asked children age 8 and older whether they were teased about their height and how frequently they were treated as if they were younger. He found both experiences to be common among short children, he said. "Nobody likes to be teased," he said, but such stressors did not translate into dysfunction.

Wintergerst likens his role as a pediatric endocrinologist to that of a detective looking for clues while investigating why a child may be growing poorly. Tests for growth hormone may be inconclusive. Decisions for treatment are based on the potential benefits, he said, and careful examinations to find the appropriate candidates.

When the treatment brings the child's height closer to normal, "you see this incredible change in their personalities and their happiness," he said,