Abstract: Objective To analyze the correlation of type 2 diabetes mellitus (T2DM) with macroangiopathy with the expression of neutrophil gelatinase related lipid transporter (NGAL) and pretibial pigmentation spot. 
Methods A total of 400 T2DM patients in our hospital were selected and divided into the observation group (n=103) and the control group (n=297) according to presence of combined macroangiopathy. The plasma NGAL expression and pretibial pigmentation spots were compared between two groups. The Spearman correlation analysis was used to analyze the correlation of T2DM with macroangiopathy with NGAL and pretibial pigmentation spots. The clinical data of all patients were collected, and binary logistic regression analysis was used to analyze the factors influencing macroangiopathy in T2DM patients. The receiver operating curve (ROC) was established to evaluate the combined diagnostic value of plasma NGAL level and pretibial pigmentation spot in T2DM patients with macroangiopathy. 
Results Compared with the control group, the level of NGAL in the observation group was higher, and the incidence of pretibial pigmentation spot (64.08%) was higher, with a statistically significant difference (P＜0.05). T2DM with macroangiopathy was positively correlated with pretibial pigmentation spot (P＜0.05). Compared with the control group, the observation group had a higher proportion of smoking and drinking, and higher levels of hemoglobin A1c (HbA1C), fasting plasma glucose (FPG), 2 hour postprandial blood glucose (2 hPG),  triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C), with a significant difference (P＜0.05). Logistic regression analysis showed that the incidence of pretibial pigmentation spot, NGAL level, alcohol consumption, TG, TC, and LDL-C were the factors influencing T2DM with macroangiopathy (P＜0.05). ROC results showed that the incidence rate of pretibial pigmentation spot and NGAL level alone and in combination in diagnosing T2DM with macroangiopathy were 0.719, 0.896, and 0.911, respectively, the sensitivity was 0.641, 0.757, and 0.777, respectively, and the specificity was 0.798, 0.902, and 0.936, respectively. 
Conclusion The occurrence of macroangiopathy in T2DM patients is related to NGAL and pretibial pigmentation spot. The combination of the two indicators can provide certain reference for clinical diagnosis and prevention of T2DM with macroangiopathy.

Key words: diabetes mellitus, type 2,  , diabetic angiopathies, influencing factor analysis