Assessment of Pro-inflammatory Cytokines in Type 2 Diabetes Mellitus Patients With and Without Complications: A Case-control Study

Introduction: Numerous factors play a significant role in the development of vascular complications in Type 2 Diabetes Mellitus (T2DM) patients. Among all of them, inflammation is considered an important factor in the development of these complications. Pro-inflammatory cytokines like Interleukin-6 (IL-6) and Tumour Necrosis Factor–α (TNF-α) interfere with insulin signalling pathways in pancreatic β-cells, contributing to insulin resistance. The role of these pro-inflammatory cytokines in the development of vascular complications in T2DM patients remains incompletely understood. Aim: To assess the serum levels of pro-inflammatory cytokines (IL-6 and TNF-α) and to determine their association with vascular complications in T2DM patients. Materials and Methods: This observational, case-control study was conducted at the Outpatient Department (OPD) of Medicine, Gandhi Medical College, Bhopal, Madhya Pradesh, India, from July 2024 to March 2025. A total of 246 T2DM cases (123 without and 123 with vascular complications) were recruited and matched with 246 healthy, age and gendermatched controls. Baseline parameters {age, gender, duration of disease, Body Mass Index (BMI), Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP)} were recorded and serum levels of IL-6 and TNF-α were analysed. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) version 30.0. Statistical analyses included unpaired ‘t’ test, Pearson’s correlation multiple logistic regression and multiple linear regression. A p-value <0.05 was considered statistically significant. Results: Significant differences in mean age were observed between controls and cases with complications (p-value <0.001), while other comparisons were not statistically significant. Males outnumbered females. Significant (p-value <0.001) increase in IL-6 and TNF-α levels were found in T2DM cases with complications as compared to cases without complications and controls. Pearson’s correlation analysis revealed a significant positive correlations of IL-6 (r-value=0.872; p-value <0.001) and TNF-α (r-value= 0.912; p-value <0.001) with T2DM duration in T2DM cases without complications, similarly it also showed significant positive correlations of IL-6 (r-value=0.843; p-value<0.001) and TNF-α (r-value=0.806; p-value <0.001) with T2DM duration in T2DM cases with complications. Logistic regression analysis demonstrated that higher IL-6 and TNF-α levels were independently associated with vascular complications. Conclusion: In the present study, serum levels of IL-6 and TNF-α were found significantly increased in T2DM cases with complications as compared to cases without complications and were also found significantly associated with T2DM duration and vascular complications. Therefore, the assessment of these biomarkers may serve as potential markers for risk stratification of vascular complications in T2DM.