Clinical Significance of Matrix Metalloproteinase-9 in Patients with Type 2 Diabetes Mellitus and Pulmonary Nodules

In this study, we examined the clinical relevance of serum Matrix Metalloproteinase- 9 (MMP-9) in patients with Type 2 Diabetes Mellitus (T2DM) presenting with Pulmonary Nodules (PNs) and its association with different nodule densities.

In total, 240 participants were recruited, including 60 individuals each with T2DM and Ground-Glass Nodules (GGNs; group A), T2DM and Solid Nodules (SNs; group B), T2DM without PNs (group C), and healthy controls (group D). Serum MMP-9 levels were measured using an enzyme-linked immunosorbent assay and analysed for correlations with clinical parameters.

Serum MMP-9 levels were significantly higher in group A than in groups B, C, and D (P < 0.01). MMP-9 levels were higher in group B than in groups C (P < 0.05) and D (P < 0.01), and higher in group C than in group D (P < 0.01). MMP-9 levels were positively correlated with fasting blood glucose (r = 0.277, P < 0.01) and glycated haemoglobin levels (r = 0.344, P < 0.01). Logistic regression analysis identified that MMP-9, HbA1c, and total cholesterol were independently associated with the presence of PNs in T2DM. The area under the receiver operating characteristic curve of MMP-9 was 0.722 for diagnosing PNs and 0.822 for diagnosing GGNs.

The increased serum MMP-9 levels observed in patients with T2DM and pulmonary nodules, particularly ground-glass nodules, indicate a possible association between matrix remodelling activity and nodule characteristics in diabetic individuals. The positive relationship between MMP-9 and glycaemic parameters further supports a link between metabolic status and pulmonary nodule profiles. These results highlight the potential relevance of MMP-9 as a supplementary biomarker in this population.

Serum MMP-9 levels were significantly elevated in patients with T2DM and PNs, particularly in those with GGNs, suggesting that MMP-9 may have clinical relevance in characterizing PNs in diabetic populations.