Cortical thickness and hippocampal volume in adolescent children with obstructive sleep apnea

Study Objectives: Intermittent hypoxia and sleep fragmentation due to obstructive sleep apnea (OSA) may contribute to oxidative tissue damage and apoptotic neuronal cell death, inflammation, and intracellular edema in the brain. We examined whether OSA in overweight and obese adolescent children is associated with cortical thickness and hippocampal structure compared to overweight and obese controls and whether OSA severity is associated with measures of brain integrity. Methods: We calculated cortical thickness and hippocampal subfield volumes from T1-weighted images of 45 controls (age 15.43 +/- 1.73 years, 21 male) and 53 adolescent children with OSA (age 15.26 +/- 1.63 years, 32 male) to investigate the association of childhood OSA with the alteration of cortical structure and hippocampal subfield structural changes. In addition, we investigated the correlation between OSA severity and cortical thickness or hippocampal subfield volume using Pearson's correlation analysis. Results: We found cortical thinning in the right superior parietal area of adolescent children with OSA (cluster size 32.29 mm(2), cluster-wise corrected p-value =.030) that was negatively correlated with apnea-hypopnea index (AHI) (R=-0.27, p-value =.009) and arousal index (R=-0.25, p-value =.014). In addition, the volume of the right subiculum-head area of the hippocampus of adolescent children with OSA was larger than controls (0.19 +/- 0.02 ml vs. 0.18 +/- 0.02 ml, ss = 13.79, false discovery rate corrected p-value =.044), and it was positively correlated with AHI (R = 0.23, p-value =.026) and arousal index (R = 0.31, p-value =.002). Conclusions: Our findings provide evidence for OSA-associated brain structure alterations in adolescent children prior to the onset of treatment that likely have important implications for timely intervention and continued monitoring of health outcomes.