Cocaine and amphetamine regulated transcript and brain-derived neurotrophic factor in morbid obesity. One-year follow-up after gastric bypass

Background: The identification of biomarkers associated with obesity and response to treatment could represent an important advance 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 in this equation.

Objectives: 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 and brain-derived neurotrophic factor, 2 neuropeptides related to eating behavior.

Setting: University General Hospital of Ciudad Real, Spain.

Methods: Twenty-seven morbidly obese patients and 30 healthy weight individuals matched by age and sex were selected for the study.

Results: Patients underwent bariatric surgery by Roux-en-Y gastric bypass and responded adequately in terms of weight loss and normalization of many biochemical parameters 1 year postsurgery. A multivariate analysis showed that the hormonal/neuropeptidic profile explained 82% of the variability of the weight loss response. The evolution of cocaine and amphetamine regulated transcript paralleled that of insulin and leptin, serum levels of this peptide were initially elevated in patients (4.24 ± .47 ng/mL) with respect to controls (2.94 ± .2 ng/mL), but this difference disappeared 1 year after Roux-en-Y gastric bypass (3.14 ± .26 ng/mL). Brain-derived neurotrophic factor levels were also decreased by Roux-en-Y gastric bypass (11.93 ± .96 ng/mL postsurgery versus 15.3 ± 1.02 ng/mL presurgery), even when this peptide was not elevated in patients before surgery (14.23 ± .86 ng/mL in controls).

Conclusions: The results suggest that cocaine and amphetamine regulated transcript and brain-derived neurotrophic factor could be envisaged as new candidate biomarkers of short-term outcome after surgery.