A study has found that short boys are three times more likely to be treated with human growth hormone than are short girls. This appears to happen even though equal proportions of girls and boys are under the threshold for what is called idiopathic short stature (ISS). This gender inequality may mean that medical problems that are causing growth problems in girls may go untreated.
"Growth is an important sign of child health, so growth failure merits equal consideration for both boys and girls," said Adda Grimberg, M.D., lead author on the study and a pediatric endocrinologist at CHOP. "Gender bias in treatment may have doubly undesirable effects-short girls who have an underlying disease may be overlooked, while short healthy boys may receive overzealous, unnecessary treatment with an expensive drug that requires years of nightly injections and has potential side effects."
Human growth hormone is approved by the U.S. Food and Drug Administration to treat children who are at the bottom of the growth charts for normal growth. The definition of ISS is height that is more than 2.25 standard deviations from the average height for age and sex. This statistical measurement translates to a child being in the bottom 1.2% in height for their age and sex.
The study team looked at information from 28 primary care practices that are affiliated with The Children's Hospital of Philadelphia (CHOP). They compared nearly 190,000 children to almost 94,000 children in pediatric growth hormone registries. There were 2,073 children in the primary care group who were below the threshold for ISS. The prevalence of ISS was no different between both girls and boys in the group from the primary care practices.
However, 74% of the patients in the growth hormone registry, the ones who were receiving human growth hormone, were boys. The percentage of boys being treated with growth hormone for any reason, not just where the cause was not known, was 66%. The boys treated for short stature outnumber the girls at every age.
Previous studies have shown that girls with growth problems are referred to endocrinologists for treating short stature when they have already fallen further behind in height than boys.