Purpose: To analyze brain ratio alternation trend of Chinese children among healthy normal weight, overweight and obese children.
Methods: Forty-eight healthy 8- to 14-year-old children whose body mass index was either <75th percentile (normal weight) or >85th percentile (overweight) or >95th (obese) completed an MRI examination which included T1-weighted three-dimensional structural imaging. A cerebral volumetry analysis software was used to compare the regional gray and white matter ratio among the normal weight, overweight and obese children. ANOVA and chi-square were used to analysis the group differences in demographic variables. One way ANOVA compared differences across BMI groups for brain ratio. Relationship between BMI and brain ratio of various brain segments were assessed by one-tailed partial correlations adjusting for age.
Results:
Whole brain parenchyma revealed significant lower ratio in obesity (p<0.001) or overweight (p=0.038) children. BMI was negatively associated with whole brain parenchyma(r=-0.319, p=0.004).The GM were significant lower in total GM (p=0.013, p<0.001), bilateral frontal lobe(p=0.011/0.001,p=0.024/0.005), left temporal lobe(p=0.001,p=0.016) and bilateral insular(p=0.004/0.043, p<0.001) of overweight or obesity children . Significant lower GM ratio of bilateral occipital lobe (p=0.027/0.001) and left cingulate lobe (p=0.03) was only detected in obesity children while lower GM ratio of right cingulate lobe (p=0.01) was found in overweight children. BMI was negatively associated with the total GM (r=-0.557, p<0.001), GM ratio of bilateral frontal lobe(r=-0.349, p=0.009; r=-0.378,p=0.005), bilateral occipital lobe(r=-0.341,p=0.01; r=-0.486, p<0.001), bilateral insular(r=-0.387,p=0.004; r=-0.563, p<0.001) and right cingulate Lobe(r=-0.56, p<0.001).Differences in WM volume was only detected in right temporal lobe (p=0.01), where obesity children had higher ratio than normal weight ones. Compared with the normal weight children, the obesity ones had lower ratio in bilateral ventral DC (p=0.014/0.007) and putamen (p=0.013/0.046). Meanwhile, differences in ratio were detected in medulla (p=0.23) and pons (p=0.04), where overweight had higher ratio than obesity. Negative association with BMI were detected in bilateral ventral DC (r=-0.286, p=0.027; r=-0.174, p=0.011) and putamen (r=-0.452, p=0.001; r=-0.382, p=0.004).Right frontal lobe (p=0.031), bilateral occipital lobe(p=0.048/0.042) and left parietal lobe(p=0.017) revealed higher ratio of atrophy degree in obesity children than normal ones. Positive association with BMI were detected in right frontal lobe(r=0.329, p=0.013), right occipital lobe(r=0.329, p=0.013) and left parietal lobe(r=0.3, p=0.022).
Conclusion: We used a volumetry tool (AccuBrain) to analysis ratio alternation trend of Chinese children among healthy normal weight, overweight and obese children. Our results revealed that atrophy of brain become greater as BMI increase. The alternation process of reward system can be persistence and deteriorating. Eventually, obesity will lead an association with dysregulated activation in a distributed network of areas involved in reward, emotion, motor planning and cognitive control.