INTERMEDIATE-DENSITY LIPOPROTEIN AS AN INDEPENDENT RISK FACTOR FOR AORTIC ATHEROSCLEROSIS IN HEMODIALYSIS-PATIENTS

Patients with chronic renal failure often show accumulation of interme diate-density lipoprotein (IDL). Because recent studies have emphasize d the atherogenicity of IDL in the general population, we evaluated th e relationship between this lipoprotein and aortic atherosclerosis in uremic patients treated with hemodialysis. Aortic pulse wave velocity (PWV) was measured as a noninvasive index of sclerotic change of aorta in 205 hemodialysis patients and 184 age- and gender-matched healthy subjects. Fasting plasma lipoproteins were fractionated by ultracentri fugation into very low-density lipoprotein (VLDL), IDL, LDL, and HDL. Plasma lipoprotein (a) (Lp(a)) was measured by a latex immunoturbidime tric assay. Aortic PWV was significantly higher in the hemodialysis pa tients than in the control subjects. The hemodialysis group showed a s ignificant increase in VLDL and IDL cholesterol, whereas their LDL and HDL cholesterol were lower than the control levels. Lp(a) levels did not differ between the two groups. In the hemodialysis population, VLD L, IDL, and LDL cholesterol correlated positively with aortic PWV adju sted for age, gender, smoking, and BP, whereas Lp(a) did not. Multiple regression analyses indicated that plasma triglycerides, independent of HDL cholesterol, had a significant association with aortic PWV in t he hemodialysis patients but not in the control subjects. Further anal yses revealed that aortic PWV in the hemodialysis patients had a signi ficant and independent association with IDL cholesterol, whereas aorti c PWV in the control subjects had significant and independent associat ions with HDL cholesterol and Lp(a). These results demonstrate that ID L is the lipoprotein fraction most closely associated with aortic PWV in the hemodialysis patients.