Children, Growth Hormone, & Possible Risk Later
Parents should discuss pros and cons of treatment with their child's doctor, researchers suggest
The current research was done as follow-up to a 2012 French study that showed larger numbers of deaths from strokes in those taking growth hormone.
The researchers wanted to dig a little deeper this time. The first study tapped French data on long-term mortality and illness in a mandatory registry for patients treated with growth hormone. The new research analyzed incidence of all stroke subtypes among adults between 2008 and 2010 who were treated as children with growth hormone between 1985 and 1996.
The study included almost 7,000 children born before 1990 who started treatment between 1985 and 1996. From 2008 to 2010, the researchers followed up with health questionnaires and tapped information from medical records and death certificates, if a participant died.
Participants were, on average, 11 years old when they started growth hormone treatment and took it for about four years. Comparison data for stroke incidence in a comparable time period were obtained from population-based registries in France and the United Kingdom.
During the follow-up time period, 11 of the participants had a stroke; eight of the strokes were hemorrhagic. The strokes occurred at an average age of 24, and four people died as a result of the stroke.
That compared to three to seven expected strokes in total in the general populations, with two of those being hemorrhagic strokes.
Hemorrhagic stroke occurs when a weakened vessel ruptures and bleeds into the surrounding brain tissue, according to the American Heart Association.
Despite the large size and scope of the study, the researchers said there are notable unresolved questions. Scientists still do not fully understand why or how growth hormone may affect stroke risk, or what characteristics of a child or adolescent might increase his or her individual risk. And while the study showed an association between use of growth hormone and an increased stroke risk, it did not establish a cause-and-effect relationship.
Researchers still have no idea what the effect of taking growth hormone in childhood might have over longer periods of time.
"It's an additional elephant in the room, what happens to these individuals when they experience aging," said Ichord. "Who knows what the same population might be like in their 40s, 50s or 60s?"