Higher levels of thioredoxin interacting protein (TXNIP) in patients with prediabetes compared to obese normoglycemic subjects.

Abstract

Background: Thioredoxin interacting protein (TXNIP) is one of the mediators of oxidative stress induced beta-cell glucotoxisity. TXNIP might play a key role in impaired glucose homeostasis preceding overt T2DM. The aim of the present study was to compare TXNIP levels between patients with prediabetes and obese normoglycemic controls and to evaluate the link between TXNIP and metabolic risk factors.

Patients and methods: In the present study we included 79 patients with mean age 50.3 ± 10.6 years, divided into two age and BMI matched groups -control group with obesity without glycemic disturbances (NGT) (n = 40) and prediabetes (n = 39).

Results: We found significantly higher levels of TXNIP in patients with prediabetes compared to normoglycemic obese controls (54.2 ± 69.9 vs. 23.9 ± 47.1 pg/ml; p = 0.03). The levels of TXNIP gradually increased from normal glucose tolerance trough IFG/IGT only to IFG + IGT (27,1; 44.0; 49.9 and 95.7 pg/ml respectively; p = 0.025 between NGT and IFG + IGT). TXNIP levels correlated weakly only with fasting blood glucose (r = 0.235; p = 0.04) but not with glucose during OGTT or the markers of insulin resistance.

Conclusions: The levels of TXNIP are higher in patients with prediabetes compared to normoglycemic controls as they increase gradually from NGT trough IFG/IGT only to IFG + IGT.