Background: Cognitive function has been shown to improve following GH treatment in adults. In children born small for gestational age (SGA) IQ scores were found to improve following 24 months of GH treatment.
Objective and hypotheses: The aim was to observe cognitive function in pre-pubertal, short children with isolated GH deficiency (IGHD) or idiopathic short stature (ISS) during the first 24 months of GH treatment. Cognitive testing was carried out using the Wechsler Scales of Intelligence at baseline, 3, 12, 24 months.
Method: A prospective, randomized multi-centre study in four centres in Sweden. 99 children (311 years/41 GHD; 58 ISS) fulfilling the per-protocol criteria were analysed. Multiple regression models were tested for the GHD and ISS populations.
Results: A significant increase in full scale IQ (P<0.001; Cohens d=0.63); performance IQ (P<0.001; Cohens d=0.65) and Processing Speed Index (PSI) (P<0.005; Cohens d=0.71) were found in the IGHD population. Only one regression model for PSI could be constructed in the IGHD population. GHmax entered into the model first followed by IGF1SDS at baseline; together they explained 40% (adj. R2) of the variance.
Conclusion: An association between GH treatment and increases in IQ variables was found. The greatest improvements were in the non-verbal IQ variables, mostly in the IGHD sub-population with PSI showing the greatest improvement. The regression analysis indicated that the children with the lowest GH levels were the most likely to gain a cognitive benefit from GH treatment.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology