A Pilot Study: The Effect of Roux-en-Y Gastric Bypass on the Serum MicroRNAs of the Type 2 Diabetes Patient

The purpose of this study was to investigate the effect of Roux-en-Y gastric bypass (RYGB) on the serum microRNA of the type 2 diabetes (T2D) patient with different body mass indexes (BMI) or blood insulin and C-peptides. Fifteen patients with T2D who elected to undergo gastric bypass surgery were separated into two groups, using BMI = 30 kg/m(2) as a reference point. Serum samples of venous blood were then collected before operation and 3 months after operation. After RYGB, there was an obvious change in the serum microRNA expression of both low- and high-BMI groups compared with those before operation. The expression of let-7, miR-24, miR-24-23a/b, miR-24-93, miR-24-26a, miR-24-151-3p, miR-24-425, miR-24-151-5p, miR-24-146a, and miR-24-103a were downregulated, whereas miR-4787-5p and miR-24-1281 were upregulated. Furthermore, there were more serum miroRNAs in the low-BMI group that changed notably, whereby miR-16, miR-17, miR-19b, miR-20a, miR-25, miR-106a/b, miR-107, miR-451, and miR-92a were downregulated, while miR-320a/b/c were upregulated. With improvement in fast glucose and insulin resistance of both low- and high-BMI groups, RYGB could modulate the expression of many serum microRNAs which are maybe associated with obesity, insulin secretion, and insulin resistance. However, in the low-BMI group, the expression of serum microRNA changed more obviously compared with the high-BMI group. This indicates that microRNA may play an important and unique role in the effect of RYGB on the improvement of insulin secretion and insulin resistance (IR), other than that played by decreased weight and body fat factors.