Resting-state brain connectivity changes in obese women after Roux-en-Y gastric bypass surgery: A longitudinal study

Abstract

Bariatric surgery is an effective method to rapidly induce weight loss in severely obese people, however its impact on brain functional connectivity after longer periods of follow-up is yet to be assessed. We investigated changes in connectivity in 16 severely obese women one month before, one month after and one year after Roux-en-Y gastric bypass surgery (RYGB). 12 lean controls were also enrolled. Resting-state fMRI was acquired for all participants following an overnight fast and after a 260 kcal load. Connectivity between regions involved in food-related saliency attribution and reward-driven eating behavior was stronger in presurgery patients compared to controls, but progressively weakened after follow-up. At one year, changes in networks related to cognitive control over eating and bodily perception also occurred. Connectivity between regions involved in emotional control and social cognition had a temporary reduction early after treatment but had increased again after one year of follow-up. Furthermore, we could predict the BMI loss by presurgery connectivity in areas linked to emotional control and social interaction. RYGBP seems to reshape brain functional connectivity, early affecting cognitive control over eating, and these changes could be an important part of the therapeutic effect of bariatric surgery.

Resting‐State Brain Connectivity Predicts Weight Loss and Cognitive Control of Eating Behavior After Vertical Sleeve Gastrectomy

“…We found that FC between the DMN nodes with clusters in the DMN and paralimbic somatosensory regions was altered to such a degree that positive correlations pre surgery “switched” to become anticorrelated post surgery. Although reduced FC between DMN nodes and anterior middle temporal gyrus was reported in RYGB patients scanned at similar time points , to our knowledge, we are the first to identify anticorrelations in the DMN in SG patients 1 year post surgery. DMN connectivity has been associated with self‐awareness and introspection , and both DMN intranetwork correlations and DMN internetwork anticorrelations were proposed to be integral to consciousness .…”

“…The post‐RYGB group showed similar FC strength within the DMN compared with a lean group, suggesting weight loss following RYGB and/or the surgery itself normalized aberrant FC associated with obesity . In a recent longitudinal study, connectivity between the precuneus and anterior superior temporal gyrus decreased from before to 1 year after RYGB compared with no changes in individuals with lean BMI scanned at a parallel interval . Within the RYGB group, there was a reduction in FC strength between the PCC (a node in the DMN) with the anterior superior temporal gyrus and anterior temporal fusiform gyrus .…”

“…In a recent longitudinal study, connectivity between the precuneus and anterior superior temporal gyrus decreased from before to 1 year after RYGB compared with no changes in individuals with lean BMI scanned at a parallel interval . Within the RYGB group, there was a reduction in FC strength between the PCC (a node in the DMN) with the anterior superior temporal gyrus and anterior temporal fusiform gyrus . Presurgery FC between the paracingulate gyrus and amygdala predicted 1‐year BMI loss, such that greater baseline FC was associated with greater BMI loss .…”

“…The SN is linked to integration of high‐level sensory information with visceral, autonomic, and hedonic signals . Recent studies have investigated the effects of bariatric surgery on FC, with assessments of patients at 1 , 3 to 4 and 12 months post surgery. In a cross‐sectional study, individuals with severe obesity who did not undergo surgery demonstrated increased FC strength within the DMN compared with Roux‐en‐Y gastric bypass (RYGB) patients scanned at least 1 year after surgery .…”

“…The SN is linked to integration of high-level sensory information with visceral, autonomic, and hedonic signals (15). Recent studies have investigated the effects of bariatric surgery on FC, with assessments of patients at 1 (16,17), 3 to 4 (18,19) and 12 (9,20) months post surgery.…”