Estudo da relação da obesidade na adolescência com alterações da conectividade cerebral por ressonância magnética funcional em estado de repouso

Abstract

Introduction: Obesity in childhood and adolescence represents a concerning healthcare issue, being considered a global epidemic by the World Health Organization and an important risk factor for adulthood obesity. The neurocognitive mechanisms that lead to obesity are still poorly understood, however new studies based on Functional Magnetic Resonance (FMR) including adult patients have revealed altered connectivities between obese and non-obese patients, which include reward related mechanisms and self control circuits. Nonetheless, these differences are not consistently studied in obese children and adolescents. Objective: To demonstrate possible differences of functional connectivity between obese adolescents and controls evaluated with Resting State FMR (RSFMR). Method: Data was obtained from 38 patients, aged between 15 and 18 years old, 16 in the obese group and 22 in the control group. The subjects underwent RSFMR, and also abdominal MR for the quantification of visceral adiposity. Body Mass Index (BMI data was also obtained. Using AFNI software, Z score maps of functional connectivity were obtained from regions of interest located in the amygdalae, posterior cingulate cortex and bilateral pre frontal cortex. These maps were correlated using t test and multiple regression analysis to the BMI and visceral adiposity data, considering a corrected p value of <0.05. Results: Group analysis showed no significant differences between obese and control patients. Multiple regressions analysis also showed no significant results with BMI data. However, multiple regression analysis with the visceral adiposity score showed decreasing functional connectivity between both amygdalae and both posterior insulae. Other reduced connectivities with this score were observed between right amygdala and cingulate cortex, the right prefrontal medial cortex and both parietal precuneus, the left prefrontal medial cortex and right precuneus and superior parietal lobule, as well as increased connectivity between the posterior cingulus and right precuneus. Conclusion: These findings suggest that adolescent obesity, specially associated with higher visceral adiposity, is also related with altered brain functional connectivity, possibly related with self-control and reward mechanisms.