Hyperapobetalipoproteinemia (HyperapoB), defined as an elevated plasma level of the major apoprotin (B) of low density (beta) lipoproteins (LDL), in the presence of a normal level of LDL cholesterol, has been previously found in at least 50% of patients with coronary artery disease (CAD). Our goals here are to determine if HyperapoB explains a significant proportion of CAD, after other risk factors for CAD are considered, and to understand better the biochemical basis of HyperapoB.
Our specific aims are to determine: 1) if an elevated plasma LDL-B protein level per se predicts the presence of arteriographically defined CAD in 200 index cases (100 men, 100 women) undergoing coronary arteriography, after the influence of other risk factors are considered. These factors are plasma levels of total cholesterol; triglyceride; cholesterol in very low density (prebeta) VLDL (d less than 1.006 g/ml), intermediate density lipoproteins (IDL, d 1.006-1.019 gm/ml), LDL (d 1.019-1.063 g/ml), total high density (alpha) lipoproteins (HDL), and HDL subfractions (HDL2 (d 1.063-1.12 g/ml) and HDL3 (d 1.12-1.21 g/ml); apoA I; and Lp(a) lipoprotein. LDL B will be measured by radial immunodiffusion (RID) in both plasma and the d greater than 1.019 g/ml untracentrifugal infranate. Blood pressure, obesity, diabetes, cigarette smoking, and family history of CAD will also be assessed. There will be two control groups: those index cases without CAD; and the spouses (n = 160) of the index cases. Univariate and multivariate analyses and a model of risk factor interaction will be used to determine if plasma LDL B level strongly and independently predicts CAD; 2) if the expression of HyperboB persists with time and is due to the presence of a smaller, denser fraction of LDL enriched in B protein and depleted in cholesterol. The index cases and spouses will be restudied (Visit 2), and a subset (36 index cases [12 hypertriglyceridemic HyperaboB; 12 normotriglyceridemic HyperaboB and 12 normal] and their spouses) will return for a third visit. The composition of LDL (cholesterol/B protein) and the sizes of the LDL fractions( determined by gradient gel electrophoresis) will be determined at Visits 1, 2 and 3. At Visit 3, LDL and its fractions will be characterized further by density gradient ultracentrifugation, chemical composition, gravimetric analysis and polyacrylamide gel electrophoresis. These studies may explain a significant proportion of the risk of CAD that is currently poorly understood and improve our understanding of HyperaboB.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL031497-02
Application #
3342662
Study Section
Metabolism Study Section (MET)
Project Start
1984-08-01
Project End
1987-07-31
Budget Start
1985-08-01
Budget End
1986-07-31
Support Year
2
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Type
Schools of Medicine
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
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Kwiterovich Jr, P O; Motevalli, M (1998) Differential effect of genistein on the stimulation of cholesterol production by basic protein II in normal and hyperapoB fibroblasts. Arterioscler Thromb Vasc Biol 18:57-64
Juo, S H; Beaty, T H; Xu, J et al. (1998) Segregation analysis of two-locus models regulating apolipoprotein-A1 levels. Genet Epidemiol 15:73-86
Juo, S H; Beaty, T H; Kwiterovich Jr, P O (1997) Etiologic heterogeneity of hyperapobetalipoproteinemia (hyperapoB). Results from segregation analysis in families with premature coronary artery disease. Arterioscler Thromb Vasc Biol 17:2729-36
Kwiterovich Jr, P O (1995) Detection and treatment of elevated blood lipids and other risk factors for coronary artery disease in youth. Ann N Y Acad Sci 748:313-30;discussion 331-2
Kwiterovich Jr, P O; Motevalli, M (1995) Inhibition of protein tyrosine kinase alters the effect of serum basic protein I on triacylglycerols and cholesterol differently in normal and hyperapoB fibroblasts. Arterioscler Thromb Vasc Biol 15:1195-203
Coresh, J; Beaty, T H; Prenger, V L et al. (1995) Segregation analysis of HDL3-C levels in families of patients undergoing coronary arteriography at an early age. Arterioscler Thromb Vasc Biol 15:1307-13
Kwiterovich Jr, P O; Motevalli, M; Miller, M (1994) The effect of three serum basic proteins on the mass of lipids in normal and hyperapoB fibroblasts. Arterioscler Thromb 14:1-7
Kwiterovich Jr, P O (1994) Dyslipoproteinemia and other risk factors for atherosclerosis in children and adolescents. Atherosclerosis 108 Suppl:S55-71
Coresh, J; Beaty, T H; Kwiterovich Jr, P O (1993) Inheritance of plasma apolipoprotein B levels in families of patients undergoing coronary arteriography at an early age. Genet Epidemiol 10:159-76

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