Aims: Recent evidence suggests that Growth Hormone Deficiency (GHD) may be associated with cognitive impairment in adults. These findings are supported by neurobiological studies documenting the presence of GH receptors in many regions of the brain, including the hippocampus and the prefrontal cortex. However to date no comprehensive investigation of the cognitive sequelae of growth hormone deficiency in children has been undertaken. We aimed to determine the effect of GHD on standardized measures of memory, executive function, IQ, motor abilities, language, behaviour and communication.
Method: Sixteen children (aged 9±1.6 years) with isolated growth hormone defiency (peak GH level < 6.7 μg/l on provocation with a low IGF1) and fourteen short stature [normal peak GH in response to stimulation (>10 μg/l), normal IGF1 measurements and normal growth rate] controls (aged 8.6±1.3 yrs) underwent a comprehensive neuropsychological assessment.
Results: We observed significantly worse performance in GHD patients compared to short stature controls on the Verbal Comprehension Index of the Wechsler Intelligence Scales for Children-IV (WISC-IV, P<0.05), Pattern Recognition Memory (P<0.05) and the Movement-ABC (P<0.05) tasks. These findings remained significant after controlling for socioeconomic status (all P values <0.05) and the presence of autistic features (all P values <0.05) in covariate analyses. No significant group differences were found on the language, behaviour and communication measures (all P values >0.05).
Discussion: These preliminary findings show subtle deficits in measures of verbal intelligence, visual memory and neuromotor function in children with GHD compared to a control group, and suggest a role for GH in specific neurocognitive functions.