NMR identifies atherogenic lipoprotein abnormalities in early diabetic nephropathy that are unrecognized by conventional analysis

Lipoprotein abnormalities are likely contributors to the high risk of cardiovascular disease in the chronic kidney disease (CKD) population, although information is limited. Specifically, little is known about lipoprotein abnormalities during the early stages of diabetic kidney disease. The aim of this study was to investigate the relationship between lipoproteins and early manifestations of CKD in the 517 Type 2 diabetes mellitus (T2DM) patients who participated in the Insulin Resistance Atherosclerosis Study (IRAS). Methods: Lipoprotein abnormalities were measured by conventional lipid analysis, nuclear magnetic resonance (NMR) spectroscopy, gel gradient electrophoresis (GE), immunoprecipitation (IP), and ELISA. We grouped the cases into albumin to creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) quartiles. Results: In the conventional lipid analysis, triglycerides (TG) correlated directly with ACR and inversely with eGFR quartiles (p = 0.01), while LDL, HDL cholesterol did not correlate with change in ACR or eGFR. ACR was directly associated with apoB, total VLDL, medium VLDL, IDL and small LDL particle concentrations (p ≤ 0.03), and inversely with large LDL particles (p = 0.01) and LDL size (p = 0.008). Estimated GFR quartiles were inversely associated with total VLDL, small VLDL, IDL, and medium HDL particles (p ≤ 0.01). Conclusion: In subjects with T2DM, mild albuminuria and reduction in eGFR were associated with numerous atherogenic lipoprotein abnormalities that were detected by the combination of NMR spectroscopy, gel gradient electrophoresis, immunoprecipitation and ELISAbut not by the standard clinical lipid analysis.