Growth hormone (GH) treatment has beneficial effects on body composition, regional fat deposition and glucose tolerance in girls with Turner syndrome, a study suggests.
"We found that GH-treated girls were leaner, with less abdominal fat and normal glucose tolerance compared with never-treated girls in the current study and compared with Turner syndrome girls in studies before the era of GH treatment," the study team reports in the June issue of the Journal of Clinical Endocrinology and Metabolism.
Individuals with Turner syndrome, who often receive GH for short stature, are at increased risk for impaired glucose tolerance and diabetes mellitus. It is unclear whether this risk is altered by GH treatment, with its insulin-antagonistic, diabetogenic actions.
To investigate, Dr. Nicole Wooten and colleagues from the National Institute of Child Health and Human Development compared adiposity and glucose tolerance in GH-treated girls (n = 76) and untreated girls (n = 26) with Turner syndrome who were between 7 and 21 years of age.
According to the team, total body fat, subcutaneous fat and intraabdominal fat were significantly greater in untreated than GH-treated girls. "The untreated group demonstrated a striking accumulation of intraabdominal fat, or visceral abdominal fat tissue, that was not seen in the GH-treated girls," they note.
The excessive abdominal adiposity in untreated girls was associated with reduced insulin sensitivity and impaired glucose tolerance. Glucose tolerance was normal in GH-treated girls.
Moreover, GH-treated girls had lower adiposity compared with untreated girls for an average of 2 years after discontinuing GH therapy.
This study, Dr. Wooten and colleagues say, suggests that girls treated with GH during childhood may be protected from the development of central, abdominal adiposity and the adverse metabolic phenotype typical of girls with Turner syndrome.
"The present findings are novel and remarkable because it was predicted by some that GH treatment would increase insulin resistance and risk for diabetes in girls with Turner syndrome," they write. "To the contrary, this study suggests that untreated girls may be at greater risk for insulin resistance and diabetes due to their excessive adiposity."
J Clin Endocrinol Metab 2008;93:2109-2114.
Reviewed by Ramaz Mitaishvili, MD
