Comparison of a dietary portfolio diet of cholesterol-lowering foods and a statin on LDL particle size phenotype in hypercholesterolaemic participants

Abstract

The effect of diet v. statins on LDL particle size as a risk factor for CVD has not been examined. We compared, in the same subjects, the impact of a dietary portfolio of cholesterol-lowering foods and a statin on LDL size electrophoretic characteristics. Thirty-four hyperlipidaemic subjects completed three 1-month treatments as outpatients in random order: a very-low saturated fat diet (control); the same diet with 20 mg lovastatin; a dietary portfolio high in plant sterols (1 g/4200 kJ), soya proteins (21·4 g/4200 kJ), soluble fibres (9·8 g/4200 kJ) and almonds (14 g/4200 kJ). LDL electrophoretic characteristics were measured by non-denaturing polyacrylamide gradient gel electrophoresis of fasting plasma at 0, 2 and 4 weeks of each treatment. The reductions in plasma LDL-cholesterol levels with the dietary portfolio and with statins were comparable and were largely attributable to reductions in the estimated concentration of cholesterol within the smallest subclass of LDL (portfolio 20·69 (SE 0·10) mmol/l, statin 2 0·99 (SE 0·10) mmol/l). These were significantly greater (P, 0·01) than changes observed after the control diet (20·17 (SE 0·08) mmol/l). Finally, baseline C-reactive protein levels were a significant predictor of the LDL size responsiveness to the dietary portfolio but not to the other treatments. The dietary portfolio, like the statin treatment, had only minor effects on several features of the LDL size phenotype, but the pronounced reduction in cholesterol levels within the small LDL fraction may provide additional cardiovascular benefit over the traditional low-fat diet of National Cholesterol Education Program Step II.Nutrition: Drugs: Lipids: Lipoproteins LDL particles are heterogeneous in terms of size, density and physical properties 1 and it is now being increasingly recognized that small dense LDL particles are associated with an increased risk of CHD 2 even in the presence of a relatively normal LDL-cholesterol concentration 3 .3-Hydroxy-3-methyl-glutaryl-coA reductase inhibitors (statins) have been shown to be effective in reducing CHD risk and mortality 4,5 and have been identified as the primary pharmacological tool in the treatment of elevated LDL-cholesterol concentration 6 . While some studies have shown small but significant benefits of statins on LDL particle diameter 7 , LDL subclass distribution 8 and on the reduction of cholesterol within the smallest LDL subfractions 9 -11 , other studies have indicated that statins had only marginal or even no effect on LDL particle size 12,13 .Although the traditional dietary approach currently recommended by the American Heart Association has been relatively efficacious in decreasing total cholesterol and LDL-cholesterol levels 14 , the magnitude of these benefits is generally modest. For that reason, the National Cholesterol Education Program Adult Treatment Panel III 15 and the American Heart Association 16 have recently recommended an increased use of functional foods with more potent effects on reducing cholesterol levels for optimal CH...

Effects of margarines and butter consumption on lipid profiles, inflammation markers and lipid transfer to HDL particles in free-living subjects with the metabolic syndrome

“…The neutral results found with both margarines are in accord with the data from the Framingham Offspring study (Campos et al, 1992) where no association was found between small dense LDL concentration and polyunsaturated fat consumption. However, our results contrast with the findings of studies where diet portfolio was tested (Gigleux et al, 2007;Lamarche et al, 2004) and where significant changes were found in the cholesterol carried in the small dense LDL fraction. This might be explained by the fact that the portfolio diet contained not only plant sterols but was also restricted in saturated fat and rich in soluble fibers.…”

“…One possibility is that cholesterol reduction occurred preferentially in bigger size LDL particles in our population. Finally, methodological differences could also explain the distinct findings: LDL particles were measured by gradient gel electrophoresis and their cholesterol content was extrapolated to the small dense LDL sub-fraction in the diet portfolio studies (Gigleux et al, 2007;Lamarche et al, 2004) whereas small dense LDL cholesterol was directly measured after precipitation in our study.…”

Serum lipid responses to phytosterol-enriched milk in a moderate hypercholesterolemic population is not affected by apolipoprotein E polymorphism or diameter of low-density lipoprotein particles

“…Our results support the idea that a decrease in TC and LDLc does not have beneficial effects on LDLc size. They suggest that PS do not affect LDLc particle size as part of their mechanism of action, which is in accordance with those of previous studies (Matvienko et al, 2002;Charest et al, 2005;Gigleux et al, 2007). It could be argued that this response is to be expected, as changes in TAG are known to be the main cause of the modification of the size of LDLc particles, and PS therapy does not alter TAG serum levels.…”

“…There is little and contradictory information with regard to the effect of PS on LDLc size. The majority of data in the literature provide evidence that LDLc size does not vary when there is a decrease in total cholesterol (TC) and LDLc (Matvienko et al, 2002;Charest et al, 2005;Gigleux et al, 2007), although some reports have shown that it increases in such conditions (St-Onge et al, 2003;Varady et al, 2005;Shrestha et al, 2007).…”

Session 4: CVD, diabetes and cancer A dietary portfolio for management and prevention of heart disease

“…013 respectively) (40) . An in-depth look into the effect of the dietary portfolio on LDL-C has demonstrated that this diet is capable of lowering the concentrations of all fractions of LDL-C, including the small dense fraction (44,45) . The dietary portfolio may also reduce oxidative damage to LDL (32) .…”