Association between serum neutrophil extracellular traps and carotid intima-media thickness in type 2 diabetes: a cross-sectional study

TL;DR

This study finds that higher levels of neutrophil extracellular traps in the blood are linked to increased carotid artery thickness in type 2 diabetes patients.

Contribution

The study establishes a novel association between serum neutrophil extracellular traps and carotid atherosclerosis in T2DM patients.

Findings

Serum NETs levels were positively correlated with carotid intima-media thickness (CIMT) in T2DM patients.

NETs were identified as an independent risk factor for carotid atherosclerosis with significant diagnostic value.

Higher CIMT groups showed progressively elevated NETs levels and other metabolic and inflammatory markers.

Abstract

Atherosclerosis is a chronic low-grade inflammatory vascular disease and serves as the core pathological basis for cardiovascular complications in patients with type 2 diabetes mellitus (T2DM). Upon activation, neutrophils release structures known as neutrophil extracellular traps (NETs), which exhibit pro-inflammatory properties and contribute substantially to atherosclerotic progression. Nevertheless, the precise relationship linking NETs to carotid atherosclerosis (CAS) among individuals with T2DM has not been fully elucidated. The objective of this research is to examine the connection between circulating NETs concentrations and carotid intima-media thickness (CIMT) values.

This study included 356 patients diagnosed with T2DM who were hospitalized in the Department of Endocrinology at Shanghai Putuo District Central Hospital between January 2024 and June 2025. Participants were stratified into three subgroups according to CIMT values. Serum NETs content was measured with a Human Neutrophil Extracellular Traps Enzyme-Linked Immunosorbent Assay Kit. Immunofluorescence staining was applied to evaluate and compare the expression of NETs-related markers across the three CIMT-based groups. Differences in baseline demographic features, laboratory indices, and CIMT measurements among the groups were systematically compared. Spearman rank correlation analysis was performed to explore associations between NETs and relevant clinical or biochemical variables. Factors contributing to CAS were further identified using binary logistic regression analysis. The predictive value of circulating NETs for CAS was assessed by receiver operating characteristic (ROC) curve analysis.

Compared with the CIMT < 1.0 mm group, the 1 ≤ CIMT < 1.5 mm group showed significant increases in body mass index (BMI), diabetes duration, systolic blood pressure (SBP), fasting plasma glucose (FPG), 2-hour postprandial glucose (2hPG), glycated hemoglobin (HbA1c), glycated albumin (GA), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), blood urea nitrogen (BUN), and NETs (P<0.05). The CIMT ≥ 1.5 mm group exhibited significant increases in BMI, number of smokers, diabetes duration, cumulative advanced glycation end products (AGEs), SBP, diastolic blood pressure (DBP), FPG, 2hPG, HbA1c, GA, TC, LDL-C, serum creatinine (Scr), BUN, estimated glomerular filtration rate (eGFR), urinary albumin-to-creatinine ratio (UACR), and NETs levels (P<0.05). Compared with the 1 ≤ CIMT < 1.5 mm group, the CIMT ≥ 1.5 mm group had significantly higher levels of BMI, number of smokers, diabetes duration, cumulative FPG, AGEs, DBP, HbA1c, GA, TC, NETs,eGFR, UACR, and LDL-C (P<0.05). Immunofluorescence indicated that with the increasing CIMT grade, the level of spontaneous NET formation by neutrophils in patients showed a significant increase. Spearman correlation analysis revealed that serum NETs levels were positively correlated with CIMT (r = 0.637, P<0.001). Logistic regression analysis identified NETs were a risk factor for CAS in T2DM patients (OR = 1.76, 95%CI 1.40–2.21, P < 0.001). Analysis using the receiver operating characteristic framework demonstrated that circulating NETs possess substantial diagnostic value for identifying carotid atherosclerosis in patients, as reflected by an area under the curve of 0.877.

Serum NETs levels were independently associated with the presence of CAS in patients with T2DM and exhibited a certain predictive value for identifying CAS. However, due to the limitations of the cross-sectional study design, the causal relationship between the two requires further validation in prospective cohort studies.

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