Patients who undergo regular haemodialysis (HD) treatment are at a high risk of atherosclerosis. Lipid abnormalities have been suggested as a major cause of the accelerated atherosclerosis and of the high incidence of coronary heart disease in chronic renal failure patients. High levels triglycerides (TAG) (very low density lipoprotein, intermediate density lipoprotein), lipoprotein(a) and low levels of high density lipoprotein chole- sterol (HDL-C) and apolipoprotein A-I (apo A-I) have been documented in many papers. Low d ensity lipoprotein cholesterol (LDL-C) and total cholesterol (T-C) are usually not elevated. In the present work the influence of a single HD on plasma lipids and apolipoproteins was studied. We compared plasma lipids (T-C, HDL-C, TAG) and apo A-I and apo B in 36 chronic renal failure patients (21 females, 15 males, age 61 ± 14.6 years, treated by HD) before and after HD. This group of patients was examined every 3 months during 15 months, 169 analyses were made. T-C, HDL-C and TAG plasma concentration were estimated with an enzyme kit, apo A-I and apo B with a immunoturbidimetric kit. Plasma albumin concentration (marker of haemoconcentration during HD) was also estimated (BCG). LDL-C (Friedewald formula), T-C/HDL-C index and apo B/apo A-I index were also calculated. After HD, we observed significant increases in T-C (from 4.92 ± 1.38 to 5.21 ± 1.58 mmol/l), HDL-C (from 1.19 ± 0.37 to 1.24 ± 0.40 mmol/l). LDL-C (from 2.84 ± 1.03 to 2.96 ± 1.14 mmol/l), TAG (from 2.01 ± 1.37 to 2.19 ± 1.26 mmol/l), apo A-I (from 1.07 ± 0.24 to 1.12 ± 0.28 g/l), apo B (from 0.78 ± 0.27 to 0.82 ± 0.29 g/l) and albumin (from 41.5 ± 4.1 to 43.0 ± 6.1 g/l). Non significant changes in T-C/HDL-C index and apo B/apo A-I index were found. There were significant positive correlations between differences (before and after HD) in albumin and T-C (r = 0.80, p<0.0001), HDL-C (r = 0.75, p<0.0001), LDL-C (r = 0.90, p<0.0001), apo A-I (r = 0.87, p<0.0001) and apo B (r = 0.62, p<0.0001). No correlation between differences in albumin and TAG was found. We suggested that changes in plasma lipids and apolipoproteins during regular HD are above all due to the haemoconcentration (the elevation of albumin concentration) and that the atherogenic lipid profile during single HD is not changed significantly.

        Key words: haemodialysis, plasma lipids and lipoproteins, haemoconcentration.