Dyslipidaemia in patients with malignant-phase hypertension

Low-density lipoprotein (LDL) consists of a heterogeneous group of particle s of differing size, density and electrophoretic mobility, smaller particle s being more atherogenic. A high proportion of small LDL particles is an in dependent risk factor for cardiovascular disease. We hypothesized that pati ents with malignant phase hypertension (MHT), the most severe form of hyper tension, would demonstrate a more atherogenic LDL subfraction profile than either non-malignant hypertension (NMHT) or normotensive controls. We compa red 16 patients with MHT to 41 patients with untreated NMHT and 45 normoten sive controls. LDL subfraction profile was measured by disc polyacrylamide gel electrophoresis using a validated scoring system to calculate the mean size (locus) and heterogeneity (spread) of LDL subfraction mobilities. A hi gher LDL locus indicates a greater proportion of small LDL subfractions. LD L cholesterol levels were similar in all three groups (p=0.23). High-densit y lipoprotein cholesterol (HDL-C) levels were significantly lower (p < 0.00 1) and serum triglyceride concentrations significantly higher (p=0.02) in t he MHT group, compared to normotensive controls. LDL locus was greater in t he NMHT group than in the normotensive controls and intermediate in the MHT group (P=0.008). There was no significant difference in LDL spread (p=0.26 ). Serum triglyceride concentrations were not significantly higher after ad justing for confounding variables. MHT is associated with an abnormal lipid profile, characterized by low HDL-cholesterol concentration. This dyslipid aemia may be partly responsible for the vascular complications and the poor prognosis of these patients.