Growth Hormone in Kids Linked to Risk of Diabetes
Feb. 18, 2000 (New York) -- Children who are given growth-hormone injections
may be at a significantly increased risk of developing type 2 diabetes,
according to a report in Saturday's issue of the journal The Lancet.
Growth hormone is often prescribed for children whose pituitary glands do not
make amounts of the hormone sufficient for normal growth. However, its use
becomes controversial when it is given to children who are merely
short-statured in order to boost their growth.
The New Zealand investigators say that the hormone injections may trigger
early onset of diabetes in children who are already at risk of developing the
disease later in life.
Type 2 diabetes develops when the cells in the body become resistant to the
effects of insulin, the hormone that allows the blood sugar, or glucose, to be
taken up into the cells and used for energy. This, in turn, leads to an
accumulation of glucose in the blood. Type 2 diabetes is usually treated with
diet and exercise, and in some cases, pills. Occasionally insulin injections
are used if previous treatments do not control the blood sugar.
"We have always been worried about growth hormone exacerbating insulin
resistance, and this is more evidence," says Allison Goldfine, MD, an
investigator at Joslin Diabetes Center in Boston. "[The finding] stresses
the importance of screening before giving growth hormone to identify glucose
status and possibly monitoring periodically."
But Goldfine tells WebMD that it's important to put the findings into
perspective, considering the psychological impact of withholding or refusing
growth hormone to a child with severe growth retardation just because there is
a possibility of developing diabetes.
The study included more than 20,000 Japanese children and adolescents age 19
and younger who were treated with growth hormone injections for an average of
nearly three years. The average age at the start of growth hormone therapy was
10 years. Most children received growth hormone for less than three years.
Overall, the risk of diabetes was six times higher for the children who took
growth hormone compared with the incidence in healthy U.S. and Japanese
children not taking the hormone.
The authors say several possible explanations could account for the high
incidence of type 2 diabetes reported in the study. "Although type 2
diabetes mellitus is thought to be rare in childhood and adolescence, there has
been a substantial increase in the incidence of this disorder in the past few
years," writes Wayne S. Cutfield, MD, a pediatric endocrinologist at the
University of Auckland.
Another possibility is that the growth hormone may have hastened the onset
of type 2 diabetes that would have occurred in adult life even if the children
had not taken the hormone.
Stephen Gitelman, MD, director of the pediatric diabetes program at the
University of California in San Francisco, says the findings are not overly