Progress and perspectives of metabolic biomarkers in blood sample for diabetic microvascular complications.

Background: Diabetes mellitus refers to a group of metabolic diseases characterized by chronic hyperglycemia due to multiple etiological factors. As the disease progresses, patients gradually develop microvascular complications, including diabetic nephropathy, diabetic retinopathy, and diabetic neuropathy. However, current clinical methods for detecting these microvascular complications are limitations, thus primary prevention and early diagnosis are of great importance.

Aim of review: This review summarizes the known blood biomarkers of diabetic microvascular complications, classified according to type of structure, including amino acid metabolism, lipid metabolism, carnitine metabolism, organic acid metabolism, etc., which can be used for the simultaneous typing of diabetes mellitus based on microvascular complications, and to search for the trend of changes to lay the foundation for early diagnosis and understanding of the pathogenesis of diabetic microvascular complications, including oxidative stress, and mitochondrial dysfunction. Searches for the trend of changes to lay the foundation for early diagnosis and understanding of the pathogenesis of diabetic microvascular complications, including oxidative stress, mitochondrial dysfunction.

Key scientific concepts of review: Due to the limitations of diagnostic criteria for diabetic microvascular complications, some patients already have the disease for which they are being tested. Metabolomics reflects the physiological state of an organism by analyzing the small molecules metabolites present in a biological tissue that are related to clinical phenotypes, providing a snapshot of the physiological and pathophysiological metabolic processes occurring within that organism at any given time, thus opening the door for the development of diagnostic biomarkers and precise treatment. In clinical metabolomics, blood is considered a specialized type of connective tissue, which allows it to transport substances throughout the body, connecting different systems together. Also, blood components are probably the most frequently used matrix in metabolomics studies. Therefore, metabolomics is used to analyze blood biomarkers that reflect the course of diabetes and explore the pathways involved in the pathophysiology of the three most common diabetic microvascular complications. Finally, in this review, we discuss the current limitations of metabolomic analysis, and the integrative multi-omics data, including genomics, transcriptomics, and proteomics, required for developing specific biomarkers for diabetic microvascular complications.