The Effect of Bariatric Surgery on the Relation Between Retinol-Binding Protein 4 (RBP4) and Vitamin D Plasma Levels in Male Obese Population

Objectives Obesity is viewed as a risk factor for several life-threatening diseases. Bariatric surgeries are regarded as a safe and effective way of treating morbid obesity and are associated with alterations in molecules such as Vitamin D and retinol-binding protein 4 (RBP4). The aim of this study was to examine an association between Vitamin D and RBP4 in healthy obese individuals undergoing gastric sleeve surgery. Methods In this observational retrospective cohort study, we used clinical and biochemical profiles of morbidly obese healthy male subjects (BMI > 38.3) who underwent laparoscopic sleeve gastrectomy. RBP4 levels were evaluated by ELISA before and 6-12 months after surgery. Data were analysed using SPSS 23 statistical software. Results RBP4/Vitamin D ratio was reduced significantly after surgery (p < 0.001), however, there was no correlation between Vitamin D and RBP4 (p = 0.353). BMI was reduced significantly after surgery (p < 0.001) but was not correlated with RBP4 or Vitamin D levels before and after surgery (p > 0.05). A significant increase in the levels of calcium post-surgery was observed (p< 0.001). Conclusions In conclusion, plasma levels of Vitamin D were not correlated with RBP4 before or after laparoscopic gastric sleeve surgery.