[Apolipoprotein E polymorphism and coronary disease]

Effect of apoE genotype on the hypolipidaemic response to pravastatin in an outpatient setting

BACKGROUND

Considerable variability exists in the plasma lipid and lipoprotein response to statin treatment due, in part, to genetic factors. The gene for apolipoprotein E (ApoE) is polymorphic and the different genotypes modulate baseline lipid levels. The objective of the present study was to evaluate the effect of the apoE genotype on the lipoprotein response to pravastatin treatment in an outpatient population followed-up in several different clinics across Spain. Subjects and methods. Subjects (n=401; 56% female; mean age 57 years), who were hypercholesterolaemic despite a diet poor in saturated fat and cholesterol, were treated according to NCEP-ATP II guidelines. Plasma lipids and lipoproteins were measured centrally before and after 16 weeks of treatment with 20 mg day-1 of pravastatin.

RESULTS

ApoE genotype distributions were 3.2% with varepsilon2/3, 73.1% with varepsilon3/3 and 22.4% with varepsilon3/4 or varepsilon4/4. ApoE genotype did not have any effect on baseline lipid levels except on triglycerides such that the carriers of the varepsilon2 allele had concentrations significantly greater than those subjects with varepsilon3/3 genotype and carriers of the varepsilon4 allele after adjustment for age, gender and body mass index (BMI) (P < 0.001). Once adjusted for age, gender, BMI and baseline lipid levels, the apoE polymorphism did not significantly influence the plasma lipid and lipoprotein response to pravastatin.

CONCLUSION

ApoE genotype appears not to influence the hypolipidaemic effect of pravastatin in patients monitored in a general outpatient setting.

[Influence of plasma lipids, APOE genotype and type of LDL receptor gene mutations on myocardial infarction in subjects with familial hypercholesterolemia]

BACKGROUND

Our goal was to analyze the relationship of lipids and lipoproteins, APOE genotype and mutations of the LDL receptor gene with the prevalence of myocardial infarction (MI) in patients with familial hypercholesterolemia (FH) from a Southern European FH population.

PATIENTS AND METHOD

We studied 108 heterozygous FH subjects aged > 35 years (41 males). It was a cross-sectional study comparing individuals with FH and MI with individuals with FH without MI. In 88 FH subjects, a mutation of the LDL receptor gene was detected. These FH subjects were divided in carriers of null mutation or no null mutations. We compared lipids and lipoproteins and prevalences of LDL receptor type mutation and APOE genotype.

RESULTS

Parameters associated with MI were: age, presence of xanthomas and arcus cornealis, plasma concentrations of total cholesterol (TC), LDLc, TC/HDLc ratio > 5.3 and *4 genotype of the APOE gene. Odds ratio for MI were as follows: presence of xanthomas and arcus cornealis, 1.36 (CI 95%, 1.08-1.71; P = 0.01), age > 54 years (50 th of FH group), 1.56 (CI 95%, 1.19-2.04; P = 0.001) and plasma TC values > 332 mg/dl (50 th of FH group), 1.34 (CI 95%, 1.05-1.71; P = 0.019). In the logistic regression model, only age and TC were significantly associated with MI.

CONCLUSIONS

In FH subjects aged over 35 years from a Southern European population, MI is associated with age, plasma TC and LDLc values, TC/HDLc ratio and the *4 genotype. In addition, MI is related with age and TC plasma levels on an independent basis.