Combined Circulating microRNA and Inflammatory Cytokine Profiles Improve Disease-Stage Discrimination of Charcot Foot in Egyptian Patients with Type 2 Diabetes Mellitus

Background/Objectives: Diabetic peripheral neuropathy (DPN) and Charcot foot (CF) represent progressive and disabling neuropathic complications of type 2 diabetes mellitus (T2DM). Circulating microRNAs and inflammatory cytokines may reflect underlying molecular alterations associated with disease progression and offer potential value for discriminating between stages of diabetic neuropathic complications. This study aimed to evaluate circulating miRNA expression profiles and inflammatory cytokine biomarkers in T2DM patients with and without neuropathic complications and to assess their potential non-invasive utility as combined biomarkers for differentiating disease stages and identifying molecular patterns associated with progression from T2DM to DPN and CF. Methods: The study included the following four groups: healthy controls, T2DM patients without complications, T2DM patients with DPN, and T2DM patients with CF. Expression profiles of five miRNAs (miR-19b-3p, miR-451a, miR-199a-3p, miR-146a-5p, and miR-93-5p) were quantified using qPCR. Inflammatory cytokine biomarkers including NLRP3, TNF-α, NF-κB, IL-1β, caspase-3, and Serpin E2 were measured using ELISA assays. Results: Distinct expression patterns of both miRNAs and inflammatory cytokine biomarkers were observed across diabetic neuropathy stages. Several miRNAs demonstrated significant dysregulation in DPN and CF compared with T2DM patients without complications. Correlation analyses revealed stage-specific patterns of interaction between inflammatory cytokines and miRNAs, indicating coordinated molecular alterations across different stages of diabetic neuropathic complications. Conclusions: These findings suggest that combining circulating miRNA and inflammatory marker profiles may improve the discrimination of CF from other diabetic neuropathic stages and may support clinical assessment when conventional diagnostic methods remain unclear. However, prospective longitudinal studies are required to determine their value for risk prediction and disease progression.