Original scientific paper
Association of Methylenetetrahydrofolate (MTHFR) and Apolipoprotein E (Apo E) Genotypes with Homocysteine, Vitamin and Lipid Levels in Carotid Stenosis
Irena Žuntar
Nataša Antoljak
Nada Vrkić
Elizabeta Topić
Nikola Kujundžić
Vida Demarin
Vlasta Vuković
Abstract
The aim of the study was to investigate the association between methylenetetrahydrofolate (MTHFR) genotypes and
levels of homocysteine (Hcy), folate, vitamin B12 and lipids as well as the association between apolipoprotein E (apo E)
genotypes and levels of lipids in a Croatian healthy control group and a group of patients with >70% carotid stenosis
(CS). The study included 98 Croats, 38 patients with >70% carotid stenosis and 60 age- and sex-matched controls. The
MTHFR and apo E genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism
(PCR-RFLP), Hcy by enzyme immunoassay, vitamins by immunochemiluminiscence, and lipids by spectrophotometric
method. There was no difference between control subjects and CS patients in the distribution of C677T MTHFR genotypes
(p=0.786) and alleles (p=0.904), however, differences in the frequencies of apo E genotypes (p=0.012) and alleles
(p=0.029) were statistically significant. The odds ratio for apo E 3/4 genotype was 3.93 (95% CI 1.23–12.61). Hyperhomocysteinemia
(15 mol/L) was found in 11% of CS patients and 5% of control subjects. Total cholesterol, triglycerides,
vitamin B12 and folate were statistically different in »all MTHFR genotypes« (p0.001, p0.01, p=0.044 and p=0.036,
respectively), and in TC/TT (p0.001, p=0.003, p=0.030 and p=0.032, respectively) groups. The levels of total cholesterol,
LDL cholesterol and triglycerides in the apo E 3/3, and total cholesterol in the apo E 3/4 group yielded statistical
difference. An association was found of apo E 3/4 genotype but not of MTHFR genotypes with the risk of CS. MTHFR
and apo E affect blood lipid levels, which was statistically confirmed. An association was also recorded between hyperhomocysteinemia
and patients with CS. Vitamin status in CS showed a statistically verified association with TC/TT
MTHFR genotype. In the group of patients with TC/TT MTHFR genotype, lower vitamin B12 and higher folate values
were recorded. The results of multiple logistic analysis showed that there was no statistical significance of Hcy levels
(OR 2.403, p=0.334) or conventional vascular risk factors such as smoking habit (OR 0.505, p=0.149), age (OR 1.048,
p=0.087) or sex (OR 2.037, p=0.112) in predicting CS.
Keywords
MTHFR; apo E; genotype; lipids; vitamin status; homocysteine; carotid stenosis
Hrčak ID:
27693
URI
Publication date:
13.12.2006.
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