The Immunometabolic Network of Diabetes Mellitus: A Review of its Mechanisms, Complications and Therapeutic Implications

Abstract

Diabetes mellitus is defined clinically by dysglycaemia but the initiation, progression and complications of diabetes are the result of reciprocal interactions between nutrient sensing, cellular stress and immune regulation. This narrative review summarizes the evidence for immunometabolic mechanisms linking insulin resistance, β-cell dysfunction and multi-organ injury. In type 1 diabetes, β-cell loss is largely driven by adaptive autoimmunity . Metabolic stress plays a role in modulating disease tempo, but this should not be confused with the initiating mechanism. In type 2 diabetes, reinforcing loops of adipose dysfunction, ectopic lipid deposition, altered insulin signaling, endoplasmic-reticulum stress, mitochondrial impairment and innate immune activation progressively erode insulin sensitivity and β-cell reserve. Activation of the NLRP3 inflammasome and interleukin-1 signaling are paradigms of molecular convergence of metabolic danger signals and inflammation. Persistent oxidative, epigenetic and inflammatory changes also contribute to metabolic memory. This helps explain why earlier glycemic exposure influences later vascular risk. Common processes—endothelial dysfunction, redox imbalance, mitochondrial injury and fibrotic signalling—are differentially expressed in the heart, kidney, retina, peripheral nerves and periodontal tissues. Since glucose, blood pressure, lipids, weight and cardiorenal risk are still actionable treatment anchors, clinical translation requires some restraint. In addition, most inflammatory and multi-omics biomarkers are still investigational. Thus, immunometabolic therapy is not a replacements but it should be an adjunct to established risk-factor management. Mechanism-informed intervention shows both promise and limitations, as demonstrated by stage-specific teplizumab in type 1 diabetes, incretin-based therapies, sodium-glucose cotransporter 2 inhibitors, and select anti-inflammatory trials.