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Plasma high density lipoprotein subfractions in subjects with different coronary risk indices as assessed by plasma
B A Griffin1, E R Skinner, R J Maughan
1Department of Biochemistry, University of Aberdeen, U.K.
Insights
Specific high-density lipoprotein (HDL) subfractions, HDL2b and apo E-rich HDL, may offer a better coronary risk index than total HDL. Lower levels of these HDL subfractions correlate with higher coronary risk.
Area of Science:
- Cardiology
- Biochemistry
- Lipid Metabolism
Background:
- Coronary risk assessment often relies on total high-density lipoprotein (HDL)-cholesterol levels.
- The composition and distribution of HDL subfractions may provide more nuanced information about cardiovascular health.
Purpose of the Study:
- To investigate the association between specific plasma HDL subfractions and coronary risk indices in healthy males.
- To determine if HDL subfractions offer superior predictive value for coronary risk compared to total HDL-cholesterol.
Main Methods:
- Gradient gel electrophoresis was used to separate HDL subfractions.
- Affinity chromatography isolated apo E-rich HDL fractions.
- Coronary risk index (CI) was calculated as total plasma cholesterol/HDL-cholesterol ratio.
- Subjects were categorized into higher (CI > 4.0) and lower (CI < 4.0) risk groups.
Main Results:
- The higher risk group exhibited lower relative concentrations of HDL2b and apo E-rich HDL compared to the lower risk group.
- Total HDL-cholesterol levels were higher in the lower risk group, primarily due to differences in HDL2-cholesterol, depending on the separation method (polyanion precipitation vs. ultracentrifugation).
Conclusions:
- Specific HDL subfractions, particularly HDL2b and apo E-rich HDL, are associated with coronary risk.
- These HDL subfractions may serve as more precise biomarkers for coronary risk assessment than total HDL-cholesterol alone.
Abstract:
The distribution of plasma high density lipoprotein (HDL) subfractions was determined in 2 groups of healthy male subjects with different coronary risk indices (CI) as assessed by the ratio of total plasma cholesterol/HDL-cholesterol. The subjects in the 2 groups were of similar age and fitness (as assessed by VO2max). The higher risk group (CI greater than 4.0) contained a lower relative concentration of a specific HDL subfraction, HDL2b, separated by gradient gel electrophoresis, and a lower level of an apo E-rich HDL fraction, isolated by affinity chromatography, than the lower risk group (CI less than 4.0). The concentration of total HDL-cholesterol was higher in the lower risk group due to a difference in HDL2-cholesterol when separation was achieved by polyanion precipitation, but not when separation was made by ultracentrifugation. These observations suggest that the level of these specific HDL subfractions might, when taken in conjunction with plasma cholesterol concentration, provide a better index of coronary risk than that of total HDL as conventionally employed.