Background: Bariatric or weight loss surgery provides the most substantial and sustainable weight loss in individuals with obesity. Caloric restriction and malabsorption are not the only mechanisms by which bariatric surgery reduces body weight and improves glycemic control. Alterations in the secretion and activity of hormones are also the contributory mechanisms in bariatric surgery. We evaluated the levels of retinol binding protein 4 (RBP4) and adipsin after gastric sleeve surgery and their relationship with insulin and lipid parameters.
Method: Thirty-three obese (BMI > 38.3) healthy male subjects age ranged from 25 to 50 years were selected for this study. Plasma levels of RBP4 and adipsin were analyzed before and six months after gastric sleeve surgery by ELISA, along with plasma glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and lipid profile.
Results: Circulating RBP4 was not significantly changed by bariatric surgery (4382.85±7.03 ng before, and 4393.28±5.769 ng after surgery, P= 0.842), neither did adipsin (2949.68±8.16 pg before, and 2917.90±7.295 pg after surgery, P=0.535). As expected, there was a reduction in BMI, insulin levels and HOMA-IR after six months of surgery. Lipid profile analysis revealed that cholesterol, high density lipoproteins (HDL), and low density lipoproteins (LDL) levels were increased after surgery (4.26±0.027 to 5.12±0.026 mmol/L and 0.90±0.007 to 1.55±0.011 mmol/L and 2.62±0.02 to 2.98±0.022 mmol/L, P<0.001) respectively. However, there was no correlation between RBP4, adipsin and insulin and lipid parameters.
Conclusions: Our findings do not suggest a role for RBP4 and adipsin in the improvement of insulin sensitivity in obese male population after gastric sleeve surgery. Moreover, there was no correlation between their plasma levels and either BMI, glucose, insulin, or lipid profiles.
S. Alshubrami: None. M. Iqbal: None. A. Alfadda: None. K. Alregaiey: None.
King Abdulaziz City for Science and Technology (1-17-03-001-0026)