Increased Neutrophil elastase and proteinase 3 are closely associated with occurrence and severity of stroke and acute myocardial infarction in patients with type 2 diabetes mellitus.

Aims: The role of Neutrophil elastase (NE) and proteinase 3 (PR3) in the occurrence and severity of stroke and acute myocardial infarction (AMI) have not been explored in type 2 diabetes mellitus (T2DM). This study aimed to investigate the relationship and predictive ability of NE and PR3 in the development of stroke and AMI in patients with T2DM, and to explore the pattern of NE and PR3 in atherosclerotic plaques.

Methods: 465 patients with T2DM (stroke or AMI, n = 234; non stroke or AMI, n = 231) were recruited. Clinical characteristics, and NE and PR3 concentration were measured in all subjects. Semi-quantitative analysis of immunohistochemistry staining for NE and PR3 was performed in detached emboli and stable plaques.

Results: Patients with stroke or AMI had a higher level of NE and PR3, with a more pronounced increase in more severe cases (higher mRS score in stroke and Gensini score in AMI) and associated with clinical markers. An increase in NE and PR3 was an independent risk factor for stroke (OR = 4.318, P = 0.017; OR = 2.979, P = 0.048, respectively) and AMI (OR = 8.385, P = 0.015; OR = 5.540, P = 0.047). Finally, immunohistochemistry staining revealed that the NE and PR3 positive area increased significantly in detached emboli compared with stable plaques.

Conclusion: Increased NE and PR3 was associated with occurrence and severity of stroke and AMI in patients with T2DM. Enriched NE and PR3 in detached emboli may be associated with plaque vulnerability.