MedicalResearch.com Interview with:
Arpana Gupta, Ph.D.
G. Oppenheimer Center for Neurobiology of Stress and Resilience
Ingestive Behavior and Obesity Program
Vatche and Tamar Manoukin Division of Digestive Diseases
David Geffen School of Medicine, UCLA
MedicalResearch.com: What is the background for this study?
Response: Past studies have demonstrated how an imbalance in the processing of rewarding and salient stimuli results in maladaptive or excessive eating behaviors. However, stress and drug use are known to affect how sex and sex hormones modulate responses of the dopamine system involved in reward, and are thought to underlie sex differences in the pathophysiology of drug addiction and treatment response. These results suggest similar sex effects on the mesolimbic reward system may also be at play in obesity.
MedicalResearch.com: What are the main findings?
Response: We found that obese men and women experience different changes in the architecture of regions of the brain responsible for reward and salience based on their sex. The findings suggest that people who are obese, who have a less responsive dopamine system, are less sensitive to reward stimuli and more prone to food intake to compensate for this deficiency. In the study subjects, sex dictated differences in signally and prominence of brain regions related to this altered ingestive behavior.
Women with obesity showed more prominent changes in the reward system related to dopamine responsiveness, suggesting they experience a greater prevalence of emotion-related and compulsive eating. Men with obesity showed a different pattern of brain remodeling in sensorimotor regions, suggesting a response that is based on awareness of gut sensations and the generation of appropriate visceral responses.
MedicalResearch.com: What should readers take away from your report?
Response: Treatments in obesity remain suboptimal, and one barrier to progress is related to the inconsistent consideration of sex differences in the underlying mechanisms. Recently there has been an increased attention to sex differences as being understood to be an important basic variable that influences the quality and generalizability of biomedical research. Our lab has made great strides to focus research that fills in these gaps related to sex differences. This has implications for future treatments.
This research builds on the current understanding of brain mechanisms underlying hedonic food ingestion but extends this knowledge by taking into account the influence of sex on reward circuits related to obesity.
Investigating sex differences in obesity within the brain’s reward circuit, will help to devise and implement more personalized and precise treatments.
Sex impacts the brain differently in obese individuals, with females showing greater alterations in the brain’s reward system related to dopamine signaling, and with males showing greater alterations in the brain’s interoceptive and somatosensory regions.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Response: In the future we plan to expand this research to investigate the corresponding sex differences in peripheral markers (inflammatory and microbiome related) observed in obesity, so that we can gain a better understanding of the bidirectional underling brain-gut mechanisms related to obesity. We are also currently looking into correlating these sex differences with behavioral and clinical data.
Disclosures: Funding: NIH NIDDK K23 DK106528, P50 DK064539, R01 DK048351, P30 DK041301
Pilot scans were provided by Ahmanson-Lovelace Brain Mapping Center at UCLA
No pharmaceutical funding was provided.
MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.
A Gupta, E A Mayer, K Hamadani, R Bhatt, C Fling, M Alaverdyan, C Torgerson, C Ashe-McNalley, J D Van Horn, B Naliboff, K Tillisch, C P Sanmiguel, J S Labus. Sex differences in the influence of body mass index on anatomical architecture of brain networks. International Journal of Obesity, 2017; DOI: 10.1038/ijo.2017.86
Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.
More Medical Research Interviews on MedicalResearch.com