Mirjam A Lips1, Marjolein A Wijngaarden1, Jeroen van der Grond1, Mark A van Buchem1, Gerrit H de Groot1, Serge A R B Rombouts1, Hanno Pijl1, Ilya M Veer1. 1. From the Departments of Endocrinology & Metabolism (MAL, MAW, and HP) and Radiology (JvdG, MAvB, and SARBR), Leiden University Medical Center, Leiden, Netherlands; the Leiden Institute for Brain and Cognition (MAvB, SARBR, and IMV) and the Institute of Psychology (SARBR), Leiden University, Leiden, Netherlands; the Department of Gastroenterology, Rode Kruis Ziekenhuis, Beverwijk, Netherlands (GHdG); and the Division of Mind and Brain Research, Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin Berlin, Berlin, Germany (IMV).
Abstract
BACKGROUND: The brain is crucial for the control of food intake, reward, and energy homeostasis. OBJECTIVE: We hypothesized that 1) brain circuits involved in energy homeostasis and reward show different functional connectivity patterns between obese and lean individuals and 2) food intake affects functional connectivity differentially in obese and lean individuals. Therefore, we compared the connectivity of the hypothalamus, amygdala, and posterior cingulate cortex, each probing a distinct network related to energy homeostasis and reward, between obese subjects and lean subjects in the fasting state and after meal ingestion. DESIGN: We acquired 3 Tesla resting-state functional magnetic resonance imaging scans after an overnight fast and after ingestion of a liquid mixed meal in 46 obese female participants [19 with normal glucose tolerance and 27 with type 2 diabetes mellitus (T2DM)] and 12 lean subjects. Functional connectivity of our regions of interest was assessed by using a seed-based correlation approach. RESULTS: No significant differences between normal-glucose-tolerant and T2DM subjects were observed. In the fasting state, the total obese group had stronger hypothalamic connectivity with the medial prefrontal cortex and the dorsal striatum than did the lean subjects. The amygdala was differentially connected to the right insula in obese compared with lean subjects. Food intake dampened hypothalamic connectivity with the frontal regions in lean subjects, whereas these connections were barely affected in obese subjects. CONCLUSIONS: Our results indicate that functional connectivity in several brain networks, particularly the homeostatic and cognitive control network and the reward network, was different between obese and lean subjects. In the fasting state, obesity appears to be associated with stronger functional connectivity between brain areas involved in cognitive control, motivation, and reward, whereas these connections are largely unaffected by food intake in obese compared with lean subjects.
BACKGROUND: The brain is crucial for the control of food intake, reward, and energy homeostasis. OBJECTIVE: We hypothesized that 1) brain circuits involved in energy homeostasis and reward show different functional connectivity patterns between obese and lean individuals and 2) food intake affects functional connectivity differentially in obese and lean individuals. Therefore, we compared the connectivity of the hypothalamus, amygdala, and posterior cingulate cortex, each probing a distinct network related to energy homeostasis and reward, between obese subjects and lean subjects in the fasting state and after meal ingestion. DESIGN: We acquired 3 Tesla resting-state functional magnetic resonance imaging scans after an overnight fast and after ingestion of a liquid mixed meal in 46 obese female participants [19 with normal glucose tolerance and 27 with type 2 diabetes mellitus (T2DM)] and 12 lean subjects. Functional connectivity of our regions of interest was assessed by using a seed-based correlation approach. RESULTS: No significant differences between normal-glucose-tolerant and T2DM subjects were observed. In the fasting state, the total obese group had stronger hypothalamic connectivity with the medial prefrontal cortex and the dorsal striatum than did the lean subjects. The amygdala was differentially connected to the right insula in obese compared with lean subjects. Food intake dampened hypothalamic connectivity with the frontal regions in lean subjects, whereas these connections were barely affected in obese subjects. CONCLUSIONS: Our results indicate that functional connectivity in several brain networks, particularly the homeostatic and cognitive control network and the reward network, was different between obese and lean subjects. In the fasting state, obesity appears to be associated with stronger functional connectivity between brain areas involved in cognitive control, motivation, and reward, whereas these connections are largely unaffected by food intake in obese compared with lean subjects.
Authors: Manpreet K Singh; Sara M Leslie; Mary Melissa Packer; Yevgeniya V Zaiko; Owen R Phillips; Elizabeth F Weisman; Danielle M Wall; Booil Jo; Natalie Rasgon Journal: Horm Behav Date: 2018-04-23 Impact factor: 3.587
Authors: John P Ryan; Helmet T Karim; Howard J Aizenstein; Nicole L Helbling; Frederico G S Toledo Journal: Neuroimage Date: 2018-01-13 Impact factor: 6.556