Background and aims: GH has profound effects on body composition and lipid metabolism in children as well as in adults. The relationship between such metabolic effects and the growth-promoting effects of GH has not been studied thoroughly in children with GH deficiency. This prospective study was designed to determine the relationship between growth and lipid metabolism during long-term GH treatment.
Patients and methods: Twenty-two boys with idiopathic GH deficiency were studied. Height, per cent overweight (%OW), per cent body fat (%BF) and serum low-density lipoprotein (LDL) cholesterol levels were determined every 6 months during 3 years of GH treatment.
Results: After 3 years of GH treatment, the mean height SD score had increased significantly from -2.70 SD to -1.59 SD (P < 0.0001), while the mean %OW and LDL cholesterol level had decreased significantly from 7.0% to 1.3% (P < 0.0001) and from 2.69 mmol/l to 2.04 mmol/l (P < 0.0001), respectively. The mean %BF fell significantly from 15.5% to 11.1% during the first 6 months of GH treatment (P < 0.0001). The 6-month reduction in %BF correlated significantly with the 3-year increase in height SD score (r = -0.58, P = 0.008). The decrease in %OW also correlated negatively with the change in height SD score (r = -0.48, P = 0.03). However, there was no correlation between the changes in LDL cholesterol levels and those in %BF, %OW or height SD score.
Conclusion: We conclude that the growth-promoting effects of GH correlate significantly with the reductions in %BF and %OW but not with the decrease in LDL cholesterol level in children with GH deficiency. The changes in LDL cholesterol did not correlate with any of the changes in body composition parameters, suggesting that the various actions of GH may have different mechanisms of regulation.