Abstract： Objective:To investigate the relationship between blood glucose fluctuation and carotid intima-media thickness (CIMT) in newly diagnosed patients with type 2 diabetes mellitus (T2DM) and the predictive value of betatrophin.Methods:A total of 180 newly diagnosed T2DM patients in Taiyuan Central Hospital from June 2018 to December 2019 were included for the study. And they were divided into normal intima-media group (81 cases), intima-media thickening group (60 cases) and plaque formation group (39 cases) according to the results of carotid ultrasound. The body test indexes, glucose and lipid metabolism indexes, blood glucose fluctuation and betatrophin level were compared among the three groups, and the correlation of these indexes with CIMT and risk factors of CIMT were analyzed.Results:The mean and maximal amplitude of glycemic excursions (AGE) in the plaque formation group and intima-media thickening group were significantly higher than those in the normal intima-media group [(5.08±0.62), (4.06±0.54) vs (3.17±0.41) mmol/L and (5.20±0.72), (4.26±0.54) vs (3.34±0.59) mmol/L] (all P<0.05), and these indexes in the plaque formation group were significantly higher than the intima-media thickening group (all P<0.05). Betatrophin levels in intima-media thickening group and plaque formation group were significantly higher than those in normal intima-media group [(423.35±76.24) and (490.68±97.84) vs (358.29±92.27) ng/L] (both P<0.05). Hip circumference and triglyceride (TG) in plaque formation group were obviously higher than those of the normal intima-media group and intima-media thickening group [(103.5±6.3) vs (97.6±7.0), (99.5±7.4) cm and 2.99 (1.32, 3.92) vs 1.70 (1.21, 2.39), 1.84(1.43, 2.93) mmol/L] (all P<0.05), and waist circumference, systolic blood pressure, fasting blood glucose (FBG), total cholesterol (TC), insulin resistance of homeostasis model assessment (HOMA-IR) levels in plaque formation group were significantly higher than those in normal intima-media group [(94.0 (86.0, 102.0) vs 88.0 (82.5, 94.0) cm, (136.2±18.0) vs (125.9±15.3) mmHg, 10.16 (8.43, 13.23) vs 8.49 (6.98, 9.97) mmol/L, (6.31±0.90) vs (4.99±0.99) mmol/L, 4.90 (3.50, 7.13) vs 2.77 (1.32, 5.07)] (all P<0.05). CIMT was positively correlated with waist circumference, hip circumference, systolic blood pressure (SBP), FBG, TC, TG, HOMA-IR, betatrophin, the mean and maximal AGE, blood glucose fluctuation coefficient (BGFC) (all P<0.05), and it was negatively correlated with time in range (TIR) ( P<0.05). The mean and maximal AGE, TC, TG and betatrophin were independent risk factors of CIMT (all P<0.05). Conclusion:Blood glucose fluctuation is closely related to CIMT in patients with T2DM, and betatrophin is expected to be an early predictor of diabetic macroangiopathy.