Elevated Level of Glycated KQTALVELVK Peptide of Albumin Is Associated with the Risk of Diabetic Nephropathy

Diabetic nephropathy is a leading cause of end-stage renal disease. Hence, early detection of diabetic nephropathy is essential to mitigate the disease burden. Microalbuminuria, the currently used diagnostic marker of diabetic nephropathy, is not efficient in detecting it at an early stage. Therefore, we explored the utility of glycated human serum albumin (HSA) peptides for risk prediction of diabetic nephropathy. Three glycation-sensitive HSA peptides, namely, FKDLGEENFK, KQTALVELVK, and KVPQVSTPTLVEVSR, with deoxyfructosyllysine (DFL) modification were quantified by targeted mass spectrometry (MS) in a study population comprising healthy and type II diabetes subjects with and without nephropathy. Mass spectrometry, receiver operating characteristic (ROC) curve, and correlation analysis revealed that the DFL-modified KQTALVELVK peptide was better than other glycated HSA peptides and HbA_1c for identifying diabetic nephropathy. DFL-modified KQTALVELVK could be a potential marker for risk prediction of diabetic nephropathy.