Changes in body composition, adipokines, ghrelin, and FGF23 in growth hormone-deficient children during rhGH therapy.

Total body fat decreased significantly in GHD children over 12 months of rhGH therapy.

• Study included 42 prepubertal, non-obese GHD children with a mean age of 9.2 ± 2.6 years
• Prospective observational study with measurements at baseline, 6 months, and 12 months
• Total body fat decreased significantly over the 12-month treatment period
• Lipid profile also improved over the course of treatment

Total bone mineral density (BMD) significantly increased over 12 months of rhGH treatment.

• BMD was measured at baseline, 6 months, and 12 months of GH therapy
• The increase in BMD was statistically significant over the 12-month period
• Changes in FGF23 concentration did not have an impact on BMD
• All children grew at an accelerated pace during the treatment period

Leptin and unacylated ghrelin (UAG) levels decreased significantly during rhGH therapy.

• Leptin levels decreased significantly over the 12 months of GH therapy
• UAG levels also decreased significantly during the treatment period
• In regression analysis models, GH therapy influences changes of leptin independently of body composition (lean or fat mass)
• The decrease in leptin was not solely explained by changes in fat mass

Adiponectin and acylated ghrelin (AG) values increased significantly during rhGH therapy.

• Adiponectin values increased over the 12-month treatment period
• AG levels increased during GH therapy
• GH therapy influences changes of adiponectin independently of body composition
• In regression analysis, GH therapy did not influence ghrelin independently of body composition

Plasma FGF23 and IGF1 increased significantly during rhGH therapy and were accompanied by increased serum phosphate.

• A significant increase in plasma FGF23 was observed over the course of GH therapy
• IGF1 also increased significantly during treatment
• Serum phosphate increased despite elevated FGF23, which was described as 'an unexpected observation given the phosphaturic role of FGF23'
• FGF23 showed a strong association with IGF1 and height standard deviation (SD)
• The authors suggest this upregulation rather than suppression of FGF23 alongside increased phosphate may reflect a role for FGF23 in linear growth

GH therapy independently influences leptin and adiponectin concentrations regardless of body composition changes.

• Regression analysis models were used to assess independence from lean or fat mass
• GH therapy influences changes of leptin and adiponectin but not ghrelin independently of body composition
• This suggests a direct effect of GH on adipokine secretion beyond the indirect effect mediated through changes in fat mass
• The authors call for further research to identify molecular mechanisms by which the GH/IGF1 axis influences adipokine secretion