Metabolismo da homocisteína e perfil lipídico de adolescentes com fatores de risco cardiovascular: relações com polimorfismos no gene da metilenotetra-hidrofolato redutase

• Autor(a) principal: Morais, Carla Cristina de
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/4778
• topic: Adolescentes; Doenças cardiovasculares; Fatores de risco; Adolescents; Cardiovascular disease; Hyperhomocysteinemia; Risk factors; CIENCIAS DA SAUDE::NUTRICAO

Objective: to investigate the prevalence of alterations in homocysteinemia, lipid profile and vitamins B6, B12 and folic acid concentrations, as well as the possible relationships among C677T and A1298C polymorphisms in methylenetetrahydrofolate reductase (MTHFR) gene and blood concentrations of these biomarkers in adolescents with cardiovascular risk factors. Material and Methods: cross-sectional study with adolescents (10-19 years old) from a public school in Goiânia, Goiás. Screening was performed with 454 students in this age group. Those who were overweight, or presented risk factors associated with family history, or had been previously diagnosed with dyslipidemia were recruited, totaling a final sample of 115 individuals. Blood concentrations of homocysteine, vitamin B6 and vitamin B12, folic acid, oxidized low density lipoprotein (ox-LDL) and lipids were analyzed. The sample was stratified according to tertiles of plasma homocysteine concentrations. Genotyping of the above mentioned polymorphisms was performed. Analysis of differences between means was performed using Student’s t test, Mann Whitney, ANOVA or Kruskal-Wallis’s test. Correlations among variables were evaluated with the Pearson’s correlation or Spearman’s test. Results: hyperhomocysteinemia was observed in 19.1% of the sample and alterations in prevalence of alterations in the lipid profile were 30.4%, with 48.0% to high-density lipoprotein, and vitamin B6 deficiency was 23, 5%. Individuals in the highest tertile for homocysteine showed blood concentrations of folic acid and HDL-c higher compared to those of the middle and lower tertile, and waist circumference greater than in those of the lower tertile. There were no significant differences in anthropometric and biochemical variables when analyzed according to the three possible genotypes realtives to the C677T and A1298C polymorphisms. However, when heterozygous and homozygous for the variant alleles for C677T polymorphism were grouped, carriers of the variant ones showed higher plasma concentrations of oxidized low density lipoprotein (p < 0.01) and vitamin B6 plasma levels (p < 0.02). Conclusion: Despite the high prevalence of hyperhomocysteinemia, it was not observed it was not observed relationship of C677T and A1298C polymorphisms with plasma concentrations of homocysteine. However, the results of the study revealed the influence of MTHFR C677T genotype on vitamin B6 and oxidized low density lipoprotein levels.