Background: Analysis of the expression of genes related to the energy metabolism can elucidate the understanding of physiological and genetic factors that contribute to obesity. This study aimed to evaluate the expression of genes and its influence on resting metabolic rate and weight loss in obese patients before and after bariatric surgery.
Methods: This study was conducted on 23 women, who were divided into two groups: bariatric surgery (preoperative and 6 months after surgery) and control. Abdominal subcutaneous adipose tissue samples were collected to analyze the gene expression, and the resting metabolic rate (RMR) was measured by indirect calorimetry.
Results: Significant differences were observed in weight reduction (22 %, p = 0.01), BMI (22.5 %, p = 0.01), and RMR values (10.5 %, p = 0.01) after the bariatric surgery, while the weight-adjusted RMR increased (15.8 %, p = 0.01). Increased UCP2 expression after 6 months of Roux-en-Y gastric bypass (RYGB) as compared to preoperative period (0.764 to 1.268, p = 0.01) was observed. Analysis with weight-adjusted RMR as dependent variable revealed that UCP2 (r 2 = 0.517, p = 0.01) and PLIN1 (r 2 = 0.420, p = 0.04) expression determine the RMR values in preoperative period. Moreover, UCP2 and PLIN1 expression in preoperative period influenced the percentage of weight loss, even when adjusted for age and BMI.
Conclusions: We have demonstrated that after 6 months of bariatric surgery, there is significant increase in the UCP2 expression. Additionally, the expression of UCP2 and PLIN1 genes influences the resting metabolic rate in obese individuals and could predict the weight loss after bariatric surgery.
Keywords: Gene expression; Obesity; Resting metabolic rate.