Diabetes Complications: An Updated Review for Dentist, Optometrist, Radiologists, Nursing, Laboratory Professionals, and Other Healthcare Professionals

Abstract

Background: Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia and progressive multi-organ injury affecting vascular, neural, renal, and retinal systems. The global burden continues to rise rapidly, creating substantial clinical and economic challenges. Diabetic complications arise from interconnected macrovascular and microvascular dysfunction driven by metabolic, inflammatory, and epigenetic mechanisms. Aim: This review aims to synthesize current evidence on the molecular mechanisms, organ crosstalk, and clinical manifestations of diabetes-related complications, with emphasis on renal, cardiovascular, neurological, and retinal involvement. It also highlights emerging therapeutic strategies relevant to multidisciplinary healthcare professionals. Methods: A narrative review approach was used, integrating findings from recent experimental studies, clinical investigations, single-cell RNA sequencing, and multiomics analyses. Evidence was critically examined to map shared pathogenic pathways across diabetic complications. Results: Diabetic complications are mediated by hyperglycemia-induced oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress, chronic inflammation, and accumulation of advanced glycation end products. These processes disrupt endothelial function and activate inflammatory cascades such as NF-κB and NLRP3 inflammasome signaling. Organ-specific manifestations include diabetic kidney disease with podocyte loss and fibrosis, cardiovascular disease driven by endothelial-to-mesenchymal transition and atherosclerosis, neurodegeneration linked to blood–brain barrier dysfunction and mitochondrial injury, and diabetic retinopathy characterized by retinal vascular damage, ferroptosis, and pathological angiogenesis. Metabolic memory and epigenetic modifications sustain disease progression even after glycemic control. Conclusion: Diabetic complications represent a unified systemic disorder rather than isolated organ diseases. Integrated molecular pathways drive progressive multi-organ dysfunction, supporting the need for early intervention and multi-target therapeutic strategies.