LIPOPROTEIN ABNORMALITIES WITHOUT HYPERLIPIDEMIA IN MODERATE RENAL-INSUFFICIENCY

To characterize lipoprotein metabolism during early renal insufficienc y, plasma lipid and apolipoprotein profiles were determined in normotr iglyceridaemic (NTG, n = 31) and hypertriglyceridaemic (HTG, n = 30) m iddle-aged patients with primary renal disease and with moderately Imp aired renal function (GFR 20-55 ml/min, mean: 37.2). Mean GFR was simi lar in the two patient groups. They were compared with 102 normolipida emic control subjects. In comparison with controls the NTG patients (p lasma triglycerides TG less than or equal to 1.7 mmol/l, mean TG: 1.16 mmol/l) had significantly increased plasma concentrations of apo C-II I and apoB. The apoA-I levels tended to be lower and as a consequence the apoA-I/apoC-III ratio, considered to represent the hallmark of the altered apolipoprotein profile in renal dyslipoproteinaemia, was mark edly lower in NTG patients (8.7 versus 16.8, P < 0.001). There was als o a reduction of the antiatherogenic ratio apoA-I/apoB and an increase of the apoC-III/apoE ratio. The HTG patients (mean TG: 3.22 mmol/l) s howed the same, but even more accentuated, qualitative changes as the NTG patients. There was a fourfold increase of apoC-III in VLDL-LDL li poprotein fractions with little change in HDL in the HTG patients. In NTG patients the increase of apoC-III was found in VLDL-LDL and in HDL . Plasma insulin and PTH levels both correlated with the apoA-I/apoC-I II ratio independently of GFR and BMI. This suggests a pathogenetic re lationship between PTH-mediated alterations of insulin metabolism and the lipoprotein abnormalities. The findings of this study indicate tha t dyslipoproteinaemia in early renal insufficiency shares the same qua litative characteristics of that in advanced renal failure with accumu lation of apoB-containing lipoproteins at various stages of delipidiza tion.