The identification of biomarkers associated with obesity and response to treatment could represent an important advance in order to design more effective and personalized therapeutic strategies. The complexity of morbid obesity could be explained as the combination of genetic, biochemical, cultural and behavioral factors among others. The study of biomarkers should be considered a determinant factor taken into account into this equation.
The aim of this study was to define better biomarker profiles potentially associated to the short term outcome of bariatric surgery by paying attention to Cocaine and amphetamine regulated transcript (CART) and Brain-derived neurotrophic factor (BDNF), two neuropeptides related to eating behavior. Twenty-seven morbid obese subjects and thirty normoweight individuals matched by age and sex were selected for the study. Patients underwent bariatric surgery by Roux-en-Y gastric bypass (RYGB) and responded adequately in terms of weight loss and normalization of many biochemical parameters one-year post-surgery. A multivariate analysis showed that the hormonal/neuropeptidic profile explained 82% of the variability of the weight loss response.
The evolution of CART paralleled that of insulin and leptin: serum levels of this peptide were initially elevated in patients (4.24 ± 0.47 ng/mL) with respect to controls (2.94 ± 0.2 ng/mL), but this difference disappeared one year after RYGB (3.14 ± 0.26 ng/mL). BDNF levels were also decreased by RYGB (11.93 ± 0.96 ng/mL postsurgery vs. 15.3 ± 1.02 ng/mL presurgery), even when this peptide was not elevated in patients before surgery (14.23 ± 0.86 ng/ml in controls). The results suggest that CART and BDNF could be envisaged as new candidate biomarkers of short-term outcome after surgery.