Pathogenic roles of post-heparin lipases in lipid abnormalities in hemodialysis patients

Abstract

The relative roles of hepatic lipase and lipoprotein lipase in the pathogenesis of uremic lipid abnormalities were studied in 92 hemodialysis patients. Fasting serum cholesterol, triglyceride, and HDL-cholesterol concentrations were measured. Plasma lipoprotein electrophoretic patterns were determined in all patients. Hepatic lipase and lipoprotein lipase activities were selectively measured in post-heparin plasma in 59 patients. Hemodialysis patients had higher serum triglyceride and lower HDL-cholesterol concentrations than did their age and sex-matched control subjects. Both hepatic and lipoprotein lipase activities were reduced in hemodialysis patients. An inverse relation between lipoprotein lipase activities and serum triglyceride concentrations emerged. Lipoprotein lipase activities correlated with in vivo post-heparin fractional clearance rates of Intralipid. A positive correlation between lipoprotein lipase activities and HDL-cholesterol concentrations probably reflected impaired catabolism of triglyceride-rich lipoproteins being responsible for the low HDL-cholesterol concentrations. Hemodialysis patients (41.3%) had an abnormal lipoprotein (the 'mid-band'). While hepatic lipase activities did not correlate with any parameters of lipid metabolism, patients with 'low' hepatic lipase activities had a significantly higher prevalence of 'mid-bands' than did those with 'normal' activities. No evidence was developed to prove that the 'mid-band' lipoproteins were remnant particles.

Lack of Association between Small Dense Low-Density Lipoprotein Levels and Coronary Artery Disease in Chronic Hemodialysis Patients

“…Such abnormalities are seen in ESRD patients who are not on dialysis [4] and also in patients treated either by chronic hemodialysis (CHD) [5] or continuous peritoneal dialysis (CPD) [6, 7]. Low-density lipoprotein cholesterol (LDL-C) levels are not elevated in ESRD patients [6, 8], but changes in LDL size and composition in association with hypertriglyceridemia could potentially result in increased atherogenicity of LDL particles [9].…”

Delayed In Vivo Catabolism of Intermediate-Density Lipoprotein and Low-Density Lipoprotein in Hemodialysis Patients as Potential Cause of Premature Atherosclerosis

“…14 The abnormal lipid composition of all lipoprotein classes has been reported to be caused mainly by a combination of an impaired reversed cholesterol transport 11 and lipolytic cascade. 15 To date, only 2 apoB kinetic studies have been reported in HD patients: Chan et al injected radio-labeled VLDL into HD patients with or without hyperlipidemia and found decreased fractional catabolic rates (FCR) of VLDL-and IDL-apoB (the latter only in hyperlipidemic patients). 16 Unfortunately, the LDL turnover was not investigated in this study.…”

Lipoprotein Metabolism Abnormalities in Patients with Chronic Renal Insufficiency

“…Several investigators indicate decreased lipo protein lipase activity in renal failure (10,12). Regarding the mechanism behind the decrease in LPL activity in uremia, three theories prevail, all of them supported by clinical or experimental findings: i) reduced enzyme synthesis by the parenchyma cell; ii) circulating inhibitor(s) against the enzyme activity and iii) heparin induced depletion of the functional enzyme pool (in hemodialysis patients).…”