Background: Severe GH deficiency (GHD) leads to several metabolic effects in the body ranging from abnormal body composition to biochemical disturbances such as high insulin sensitivity. However, less is known regarding these parameters in children with a milder deficiency in GH secretion.
Objective and hypotheses: To analyse if short children with a relatively low GH secretion differ metabolically from healthy children of normal height.
Method: We examined insulin sensitivity index (Si), body composition and fasting levels of glucose, insulin and HbA1c in short children (<−2.5 SDS) between 710 years of age (n=35) and compared the results with an age- and sex-matched control group of normal height (n=12). We also performed a subgroup analysis comparing these parameters for short children above and below a peak GH secretion level of 10 μg/l during GH-stimulation test.
Results: The group of short children had a higher mean Si compared to the control group (12.9 vs 10.4 (mu/l)−1×min−1) but the difference was non-significant unadjusted (P=0.079) and only borderline significant when adjusted for sex (P=0.059). The comparison of body composition adjusted for sex showed that the short children had a lower percentage of abdominal fat (AF, 13.3% vs 16.6%, P=0.05) and higher percentage of lean body mass (LBM, 80.6% vs 77.5%, P=0.04) compared to the controls. No significant difference of fasting glucose or HbA1c was detected between the groups but fasting insulin was significantly lower in the short children (22.4 vs 32.0 pmol/l, P=0.05) when adjusted for sex. When comparing short children above and below GH-peak level of 10 μg/l the children with lower GH secretion were shown to have a significantly lower fasting insulin level (16.8 vs 27.8 pmol/l, P=0.04) and the other comparisons showed tendencies towards higher Si, lower AF and higher LBM, but these results were non-significant.
Conclusion: Short children with mildly impaired GH secretion are very heterogeneous in terms of their metabolic profile compared with healthy children of normal height. They show higher Si and lower fasting insulin levels than the healthy children but in contrast to the phenotype of GHD the short children have low AF and high LBM, which might have contributed to the differences in insulin sensitivity.
Funding: The work was supported by Eli Lilly Sweden AB, Swedish Heart-Lung Foundation, Swedish Research Council for Health, Working Life and Health Care and Karolinska Institute-Stockholm County Council Research Support.
01 - 03 Oct 2015
European Society for Paediatric Endocrinology