Effect of Sleeve Gastrectomy on Plasma Thioredoxin-Interacting Protein (TXNIP)

Purpose The mechanism in which bariatric surgery induces diabetes remission is still poorly understood. This study proposes Thioredoxin-interacting protein (TXNIP) as a possible factor for the anti-diabetic mechanism after sleeve gastrectomy (SG). Materials and Methods Plasma TXNIP level in obesity patients with diabetes (T2D, N = 20), obesity patients without diabetes (NDO, N = 20), and patients without obesity and diabetes (lean, N = 10) were assessed before surgery and at 1 and 12 months after SG. Results Preoperative TXNIP level was significantly higher in T2D (196.4 +/- 76.0 pg/ml) and NDO (149.7 +/- 94.1 pg/ml) patients when compared with lean patients (98.7 +/- 22.7 pg/ml) (p-value < 0.05). At 1 month and 12 months postoperatively, the TXNIP levels were reduced significantly from the preoperative levels in the T2D and NDO patients (p-value < 0.05). Before surgery, a correlation between TXNIP and fasting blood glucose (FBG) (r(2) = 0.1585, p-value = 0.0109), HbA1C (r(2) = 0.2120, p-value = 0.0028), and insulin (r(2) = 0.1217, p-value = 0.0274) was observed. At 12 months after surgery, the reduction of TXNIP was also correlated with the degree of FBG (r(2) = 0.1038, p-value = 0.0426), HbA1C (r(2) = 0.2459, p-value = 0.0011), and insulin (r(2) = 0.1365, p-value = 0.0190) reduction. Conclusion Plasma TXNIP level is elevated in obesity patients with/without diabetes. SG resulted in a significant reduction of plasma TXNIP level which is correlated with the degree of FBG, HbA1C, and insulin reduction. Regulation of TXNIP could be part of the mechanism of diabetes remission after bariatric surgery.