Submitted by PPG Pediatria e Sa?de da Crian?a (pediatria-pg@pucrs.br) on 2018-01-02T10:55:20Z No. of bitstreams: 1 Dissertac?a?o final Ricardo Paganin.pdf: 1872920 bytes, checksum: 7d8831f2c8ed4551b8e0568cd2551272 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-01-22T13:24:28Z (GMT) No. of bitstreams: 1 Dissertac?a?o final Ricardo Paganin.pdf: 1872920 bytes, checksum: 7d8831f2c8ed4551b8e0568cd2551272 (MD5) / Made available in DSpace on 2018-01-22T13:34:41Z (GMT). No. of bitstreams: 1 Dissertac?a?o final Ricardo Paganin.pdf: 1872920 bytes, checksum: 7d8831f2c8ed4551b8e0568cd2551272 (MD5) Previous issue date: 2017-07-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / 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. / Introdu??o: A obesidade na inf?ncia e adolesc?ncia representa um problema de sa?de preocupante, sendo considerada uma epidemia global pela Organiza??o Mundial de Sa?de e um importante fator para obesidade na vida adulta. Os mecanismos neurocognitivos que levam ? obesidade ainda s?o pobremente compreendidos, no entanto, novos estudos baseados em Resson?ncia Magn?tica Funcional (RMF), incluindo pacientes adultos, t?m revelado conectividades alteradas comparando pacientes obesos e n?o obesos, os quais incluem mecanismos relacionados a recompensa e circuitos de autocontrole. N?o obstante, estas diferen?as n?o s?o consistentemente estudadas em adolescentes e crian?as obesas. Objetivo: Demonstrar poss?veis diferen?as de conectividade funcional entre adolescentes obesos e controles, avaliados com RMF em Estado de Repouso (RMFER). M?todo: Dados foram obtidos de 38 pacientes, com idade entre 15 e 18 anos, sendo 16 no grupo obeso e 22 no grupo controle. Os sujeitos foram submetidos a RMFER, e tamb?m RM abdominal para a quantifica??o de adiposidade visceral. Dados de ?ndice de Massas Corporal (IMC) foram coletados. Usando o software AFNI, mapas de escore Z de conectividade funcional foram obtidos de regi?es de interesse localizadas nas am?gdalas, c?rtex do c?ngulo posterior e c?rtex pr?-frontal bilateral. Estes mapas foram analisados usando testes t e an?lise de regress?o m?ltipla com os dados de IMC e de adiposidade visceral, considerando significativo um valor p de < 0,05, corrigido atrav?s do software clustsim. Resultados: An?lise de grupo n?o demonstrou diferen?as em rela??o ao IMC entre os grupos obeso e n?o obeso. A an?lise de regress?o m?ltipla tamb?m n?o demonstrou diferen?as com os dados de IMC. No entanto, an?lise de regress?o com o coeficiente de adiposidade visceral demonstrou redu??o da conectividade entre ambas am?gdalas e as ?nsulas posteriores. Outras conectividades reduzidas com este coeficiente foram observadas entre a am?gdala direita e c?rtex do c?ngulo, entre o c?rtex pr?-frontal medial direito e ambos prec?neos parietais, entre o c?rtex pr?-frontal medial esquerdo e o prec?neo direito e l?bulo parietal superior direito, bem como conectividade aumentada entre o c?ngulo posterior e o prec?neo direito. Conclus?o: Estes achados sugerem que a obesidade na adolesc?ncia, especificamente associada a maior adiposidade visceral, ? tamb?m relacionada a altera??es da conectividade funcional cerebral, possivelmente devido a mecanismos de autocontrole e recompensa.