Abstract:Objective To investigate the association of serum thioredoxin (Trx) and thioredoxin-interacting protein (TXNIP) with carotid atherosclerosis (CAS) in newly-diagnosed type 2 diabetic patients. Methods Totally 160 patients newly diagnosed as T2DM in the Department of Endocrinology of Tangshan Gongren Hospital were recruited and divided into two groups according to the result of carotid artery ultrasonography, i.e. T2DM with CAS group (CAS group, 65 cases) and T2DM without CAS group (NCAS group, 95 cases). During the same period, 140 healthy controls without T2DM from the Medical Examination Center were recruited. Data including age, sex, BMI, systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG), insulin (FINS), glycosylated hemoglobin A1c (HbA1c), total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and homocysteine (Hcy) were collected. The homeostasis model assessment for insulin resistance (HOMA-IR) was calculated by FPG (mmol/L) × FINS (mU/L)/22.5. Serum Trx and TXNIP were measured by enzyme-linked immunosorbent assay (ELISA), and Trx activity was measured by insulin reduction assay. Results Compared with the normal controls, FPG, HbA1c, HOMA-IR, Trx and TXNIP levels in the T2DM patients increased, but Trx activity decreased (all P < 0.05). Compared with the NCAS group, the patients in the CAS group were older, with higher FPG, HbA1c, SBP, Trx and TXNIP levels and lower Trx activity (all P < 0.05). In the T2DM patients, Trx was positively correlated with HbA1c; TXNIP was positively correlated with HbA1c and HOMA-IR, but inversely correlated with Trx activity (all P < 0.05). In the T2DM patients, age, HbA1c, Trx, TXNIP and Trx activity were the influence factors of CAS. Age (■ = 1.134, P = 0.032), HbA1c (■ = 1.275, P = 0.021), Trx (■ = 1.532, P = 0.015) and TXNIP (■ = 1.731, P = 0.005) increased the incidence of CAS, but Trx activity (■ = 0.507, P = 0.002) was a protective factor for CAS. Conclusions Serum Trx, TXNIP and Trx activity are closely correlated with carotid atherosclerosis in newly-diagnosed type 2 diabetic patients, suggesting that Trx system may be involved in occurrence and development of carotid atherosclerosis of these patients.