Sleeve Gastrectomy Recovering Disordered Brain Function in Subjects with Obesity: a Longitudinal fMRI Study.

Objective: Bariatric surgery could recover regional dysfunction of cerebral cortex. However, it is unknown whether bariatric surgery could recover the global-level dysfunction in subjects with obesity. The aim of this study was to investigate the effect of bariatric surgery on global-level dysfunction in subjects with obesity by resting-state functional magnetic resonance imaging (fMRI).

Methods: Resting-state fMRI was used to investigate dysfunction of whole-brain in 34 subjects with obesity and 34 age-and gender-matched normal-weight subjects, in which 17 subjects with obesity received sleeve gastrectomy. Fractional amplitude of low-frequency fluctuation (fALFF) and functional connectivity (FC) among the whole brain were used to estimate the brain functional differences among the preoperative subjects, postoperative subjects, and the controls.

Results: The preoperative subjects compared to controls had decreased resting-state activities in reward processing and cognitive control regions such as orbitofrontal cortex, middle frontal gyrus, superior frontal gyrus, and gyrus rectus. It was important that increased FC was also found in these regions. Correlation analysis showed that body mass index (BMI) was associated with these decreased activity and increased FC. More importantly, the dysfunction in these regions was recovered by the bariatric surgery.

Conclusions: These results suggest that bariatric surgery-induced weight loss could reverse the global-level dysfunction in subjects with obesity. The dysfunction in these regions might play a key role in the development of obesity, which might serve as a biomarker in the treatment of obesity.