TIME medicine

Growth Hormone Linked to Higher Risk of Stroke

Children treated with growth hormone are more likely to experience strokes decades later

Since the Food and Drug Administration approved a synthetic form of growth hormone (GH) in 2003 to treat short stature in kids, it’s become a popular medication not just among parents who want their children to grow but also in locker rooms of professional athletes who believe the collagen-building features of the drug can both protect and improve recovery from injury.

Now the latest study shows that children treated with GH are at risk of bleeding in the brain nearly 20 years later. French researchers report Wednesday in the journal Neurology that among a group of children treated for short stature or low levels of growth hormone had between a 1.5 to 5.3 times higher risk of having a stroke during the follow-up period than the general population.

“Subjects on or previously treated with growth hormones should not panic on reading these results,” the authors said in a written statement. “The results of this study highlight the importance of studies of this kind for the evaluation of the long-term effects of treatment.”

While the researchers can’t explain why the hormone treatments, which are usually given in daily injections over four to five years, led to the strokes, earlier studies on animals with a metabolic disorder in which they produced excessive amounts of the hormone showed that they tend to have more bleeding events. The scientists admit, however, that it’s also possible that short stature itself may have some connection to stroke risk since other disorders in which people don’t grow properly are also linked to abnormal blood flow to the brain.

The study, which involved nearly 7,000 participants, provides good reason for people taking growth hormone to discuss the potential risk of stroke with their doctors, say the authors. Whether the findings apply to others who take growth hormone – athletes who use it for performance enhancement, or those affected by other diseases such as kidney disorders – isn’t clear yet.

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