Comparison of Serum Matrix Metalloproteinase-9 Levels in Diabetic and Non-diabetic Chronic Wounds.

BACKGROUND

Wound healing relies on a balance between extracellular matrix remodelling by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). Among all the MMPs, elevated MMP-9 levels are implicated in chronic wounds including diabetic ulcers, making it a potential biomarker to predict wound healing. This in turn can help determine the need for aggressive wound care management. However, most studies used invasive sampling methods like wound fluid or tissue biopsy limiting clinical implementation. Hence, this study assessed the correlation between serum levels of MMP-9 in diabetic and non-diabetic chronic wounds to explore if non-invasive methods could be used to predict healing in diabetic chronic wounds.

OBJECTIVE

This study aimed to compare serum MMP-9 levels in diabetic vs. non-diabetic chronic wounds, assess correlations with glycemic control (glycated hemoglobin (HbA1c)), and determine the potential of serum MMP-9 as a predictor of healing in diabetic chronic wounds.

METHODS

This was a cross-sectional study involving 40 patients (20 diabetics, 20 non-diabetics) with chronic wounds. Serum MMP-9 levels were measured from blood samples (avoiding invasive methods) using an enzyme-linked immunosorbent assay (ELISA). HbA1c levels were obtained for patients with diabetes mellitus. Statistical analysis compared means (t-test) and correlations (Pearson's).

RESULTS

Patients with diabetes mellitus had significantly higher serum MMP-9 (mean 21.22 ng/ml) in comparison to non-diabetics (17.35 ng/ml; p=0.0023). When compared to only 5% (one out of 20) of non-diabetics, about 75% (15 out of 20) of diabetics had MMP-9 greater than 20 ng/ml. However, no correlation was found between MMP-9 and HbA1c levels (p>0.05) among diabetic patients.

CONCLUSIONS

Serum MMP-9 is elevated in diabetic chronic wounds, supporting its role as a non-invasive biomarker. Several studies have established wound fluid/tissue MMP-9 as a predictor of healing in diabetic ulcers, and this study suggests that serum MMP-9 levels could be used as a non-invasive biomarker in place of cumbersome methods. However, the lack of association of MMP-9 with HbA1c suggests glycemic control alone may not regulate MMP-9. Targeting MMP-9 inhibition (e.g., via microRNAs) could be a therapeutic strategy, warranting further research.