Association Between Insulin Resistance Markers and Immunological Markers in Gestational Diabetes Mellitus

Introduction Gestational diabetes mellitus (GDM) is characterized by insulin resistance with inadequate β-cell compensation, resulting in maternal hyperglycemia and adverse fetal outcomes. Emerging evidence highlights the role of inflammatory cytokines and adipokines in driving the underlying immunometabolic changes associated with this condition. Objective This study aimed to investigate the interplay of inflammatory cytokines (IL-6, IL-10, and IL-13), adipokines (chemerin and visfatin), and C-peptide in women with GDM among the South Indian population. Methods This case-control study included 88 pregnant women (44 with GDM and 44 normoglycemic controls). Fasting plasma glucose, C-peptide, interleukins (IL-6, IL-13, and IL-10), and adipokine markers chemerin and visfatin were measured. Associations were explored using Spearman's correlation analysis. Multiple linear regression was performed as the primary analysis with fasting glucose as the dependent variable to identify independent immunometabolic determinants of glycemia. Binary logistic regression was conducted as a secondary analysis to identify glucose-independent predictors of GDM status. Results were expressed as regression coefficients and odds ratios (OR) with 95% confidence intervals (CI). Data were analyzed using IBM SPSS Statistics for Windows version 19.0 (IBM Corp., Armonk, NY). Results Women with GDM had significantly higher fasting glucose and lower C-peptide levels compared to controls (p < 0.05). Fasting glucose showed an inverse correlation with IL-6 and C-peptide, and a positive correlation with chemerin. Visfatin showed a positive correlation with IL-13. In multiple linear regression, IL-6 and C-peptide were independently and negatively associated with fasting glucose, while chemerin and gestational age were positive predictors (adjusted R² = 0.201; p < 0.001). In logistic regression, higher chemerin levels were associated with increased odds of GDM (OR = 1.010; 95% CI: 1.005, 1.016), whereas higher C-peptide (OR = 0.672; 95% CI: 0.536, 0.843) and IL-6 levels (OR = 0.796; 95% CI: 0.712, 0.890) were associated with reduced odds of GDM (all p < 0.01). Conclusion Immunological marker IL-6 and adipokine marker chemerin are independently associated with glycemic status. Chemerin may appear to contribute to insulin resistance, while IL-6 and C-peptide may reflect compensatory immune and β-cell responses during pregnancy. These findings suggest the complex immune-metabolic interplay underlying gestational diabetes mellitus.