Serum Lipocalin-2 Levels Are Increased and Independently Associated With Early-Stage Renal Damage and Carotid Atherosclerotic Plaque in Patients With T2DM

OBJECTIVES: Diabetic nephropathy (DN), one of the major complications of diabetes mellitus, is the major cause of end-stage renal failure that finally increases the risk of cardiovascular disease and mortality. The aim of this study is to explore the relationship between serum lipocalin-2 (LCN-2) levels and DN and carotid atherosclerotic plaque (CAP) in patients with type 2 diabetes mellitus (T2DM). METHODS: We have performed a prospective study of 749 T2DM patients with or without DN. Blood samples were collected and used to test serum LCN-2 levels, renal function, as well as biochemical parameters. CAP in these subjects was determined by ultrasonography. RESULTS: In these 749 subjects with T2DM, an increased morbidity of CAP was observed in T2DM patients with DN as compared with those without this complication (P < 0.05). Interestingly, serum LCN-2 levels were significantly increased in T2DM patients with DN or CAP compared with T2DM alone [97.71 (71.49-130.13) vs. 77.29 (58.83-115.05) ng/ml, P < 0.001]. In addition, serum LCN-2 levels in T2DM patients with DN and CAP were significantly higher than that of T2DM patients with DN or CAP [131.37 (101.43-182.04) vs. 97.71(71.49-130.13) ng/ml, P < 0.001]. Furthermore, serum LCN-2 levels were positively correlated with hemoglobin A1c, systolic blood pressure, hypertension, CAP, and DN, as well as renal function factors including uric acid, creatinine, the estimated glomerular filtration rate, and urinary albumin-to-creatinine ratio, respectively (P < 0.05), but negatively correlated with HDL-c (P < 0.05). The multinomial logistic regression analysis showed that serum LCN-2 was independently associated with DN and CAP in patients with T2DM after the adjustment for risk factors (P < 0.001). CONCLUSIONS: Early-stage renal damage is a risk factor associated with the incidence of CAP in patients with T2DM. Serum LCN-2 is significantly increased and associated with early-stage renal damage and the incidence of CAP in patients with T2DM.