Plasma IGF-1 levels and cognitive dysfunction in children with obstructive sleep apnea

Abstract

Background Pediatric OSA is associated with substantial morbidity in cognitive function. However, for any given OSA severity level, altered cognitive performance may or may not be present. Since IGF-1 is neuroprotective, we hypothesized that higher systemic IGF-1 levels may identify children at lower susceptibility for cognitive morbidity. Methods Consecutive habitually snoring and non-snoring children ages 5–7 years were recruited from the community, and underwent overnight polysomnography, and neurocognitive testing and a blood draw the next morning. Snoring children were divided into OSA or no OSA, and OSA children were further subdivided into those with ⩾2 abnormal cognitive subtests and into those with normal cognitive scores. Plasma levels of IGF-1 were also measured using ELISA. Results Among snoring children without OSA, circulating IGF-1 was 910 ± 110 pg/mL compared with 1070 ± 240 pg/mL in those with OSA ( p < 0.01). However, IGF-1 was 540 ± 70 pg/mL in children with OSA and cognitive deficits, compared to 1370 ± 170 μg/L in children with OSA and normal cognitive scores ( p < 0.001). Conclusions IGF-1 levels are higher in children with OSA, particularly in those who do not manifest neurocognitive deficits, suggesting that the magnitude of the IGF-1 response elicited by OSA may play a significant protective role against the neurocognitive dysfunction associated with OSA.