<p>Diabetes mellitus (DM) is marked by prolonged elevated blood glucose levels, which lead to the formation of covalent adducts between glucose and plasma proteins through a non-enzymatic reaction called glycation. This biochemical process plays a crucial role in the development of DM complications, including retinopathy, nephropathy, neuropathy, and cardiomyopathy, while also impacting conditions such as rheumatoid arthritis, osteoporosis, and aging. Glycation alters the molecular structure, enzymatic activity, and receptor interactions of proteins, affecting their normal functions. Advanced glycation end products (AGEs) arise from these modifications, forming cross-links within and between cells, which affect proteins and other vital biomolecules, such as lipids and nucleic acids. This contributes significantly to the complex complications associated with DM. Recent studies highlight the interaction between AGEs and their specific receptors, receptor for advanced glycation end products (RAGE), located on the plasma membrane. This involvement initiates changes in intracellular signaling, alters gene expression, and stimulates the release of pro-inflammatory cytokines and reactive oxygen species. This review examines the glycation of key plasma proteins albumin, fibrinogen, globulins, and collagen and discusses the various AGEs formed. Furthermore, it elucidates the role of AGEs in the exacerbation of DM complications, providing a comprehensive overview of the molecular pathways involved and the systemic impact of these glycation products.</p>