Atherogenic lipoprotein changes in diabetic nephropathy

Cardiovascular risk is increased in patients with diabetic nephropathy. The aim of this study was to examine the relative impacts of albuminuria and r enal failure, the two important features of diabetic nephropathy, on potent ially atherogenic lipoprotein changes in this condition. The subjects were 160 non-diabetic healthy controls and a total of 200 type 2 diabetes patien ts with various degrees of nephropathy. The diabetic patients were divided into four groups by urinary albumin/creatinine ratio (U-ACR) and serum crea tinine (S-Cr) levels: DM-1 (U-ACR < 30 mg/g, N=85), DM-2 (U-ACR = 30-300 mg /g, N = 38), DM-3 (U-ACR > 300 mg/g, N = 29) and DM-4 (S-Cr > 177 mu mol/l or 2.0 mg/dl, N = 38). Lipids in very low (VLDL), intermediate (IDL), low ( LDL), and high density (HDL) lipoproteins were measured following ultracent rifugation. VLDL-cholesterol (VLDL-C) was elevated (by 73-100%) in diabetic patients and it did not differ among the stages of nephropathy. IDL-C was higher as the nephropathy stage was advanced, and the elevation was signifi cant in the DM-3 (by 75%) and DM-4 (by 131%) groups. LDL-C was not elevated in diabetic patients and was not different among the stages of nephropathy . Reduction of HDL-C was significant in DM-1, DM-2 and DM-3 (by 12-16%) and it was more exaggerated in DM-4 (by 35%). Multiple regression analyses ind icated that elevated S-Cr, but not U-ACR, was an independent factor associa ted with raised IDL-C and lowered HDL-C in diabetic patients. These results indicate that diabetic patients with nephropathy show multiple lipoprotein changes, and that renal failure has greater impact than albuminuria on abn ormalities in IDL and HDL. These lipoprotein alterations may contribute to an increased cardiovascular risk in diabetic nephropathy, especially in dia betic renal failure. (C) 2001 Elsevier Science Ireland Ltd. All rights rese rved.