BACKGROUND:Apolipoprotein (apo) E is a component of two major classes of plasma lipoproteins, apo B- (apo E-LpB) and non-apo B-containing (apo E-Lp-non-B) lipoproteins. The factors that affect total apo E in particles [lipoprotein E (LpE), apo E-Lp-non-B, and apo E-LpB], are incompletely characterized.METHODS:We studied the determinants of these lipoparticles in a sample population of presumably healthy individuals: 1784 children (age range, 8-18 years) and 1739 adults (age range, 19-50 years). Serum concentrations of LpE and apo E-Lp-non-B were measured by electroimmunoassays, and the concentration of apo E-LpB was calculated by a difference method.RESULTS:Serum LpE and apo E-Lp-non-B were higher in females than in males. Their concentrations decreased with age until 20-25 years and then increased in men but not in women. apo E-LpB concentrations increased up to 20-25 years and were similar in both sexes. Thereafter, adult men had higher values than women. Individuals carrying the epsilon2 allele had higher mean apo E-Lp-non-B concentrations and lower apo E-LpB concentrations than did individuals carrying the epsilon3 allele. Individuals with the epsilon4 allele showed an inverse profile compared with those with the epsilon2 allele. Age, gender, the common apo E polymorphism, puberty, serum lipid concentrations, and alcohol consumption were significantly associated with total LpE, apo E-Lp-non-B, and apo E-LpB concentrations. Reference limits were established according to age, gender, and the common apo E polymorphism.CONCLUSIONS:Because measurements of LpE, apo E-Lp-non-B, and apo E-LpB concentrations may improve cardiovascular risk assessment, the proposed reference limits will aid interpretation of the results in clinical or therapeutic trials.

The main objective of the Stanislas cohort is to study the role and the contribution of genetic and environmental factors to cardiovascular status. We plan:a) to describe the degree of association of a large number of cardiovascular risk indicators with cardiovascular endpoints,b) to evaluate the contribution of genetic and that of environmental factors to this association,c) to follow the evolution of these risk indicators during a period of at least ten years,d) to search for the determinants influencing this evolution.The principal variables studied are:a) blood pressure, cardiac mass, and wall thickness of carotid and femoral arteries,b) obesity and fat mass,c) indicators of lipid metabolism,d) genetic polymorphisms of several cardiovascular risk candidate genes,e) food, tobacco and alcohol consumption,f) consumption of drugs and anti-oxidant vitamins.Between September 1993 and August 1995, 1006 families consisting of the two biological parents with at least two children were recruited totalling 4295 individuals. This cohort will be followed up until 2004. There will be two health examinations five and ten years after the initial examination. A bank of blood samples (serum and plasma) in liquid nitrogen and DNA (-80 degrees C) has been established.