Influência dos polimorfismos dos genes FADS e do consumo alimentar no perfil materno de ácidos graxos poli-insaturados ômega 3 e no resultado obstétrico

• Autor(a) principal: Carvalho, Gisele Queiroz
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/7134
• topic: Nutrigenomics; Single nucleotide polymorphism; Unsaturated fatty acids; Pregnanty women; Birth weight; Gestacional age; Nutrigenômica; Polimorfismo de nucleotídeo único; Ácidos graxos insaturados; Gestantes; Peso ao nascer; Idade gestacional; Biotecnologia; 61

The status of long-chain polyunsaturated fatty acids (LCPUFAs) has strong influence on prematurity and low birth weight risks. The polyunsaturated fatty acids intake (PUFA) and polymorphisms in fatty acid desaturases genes (FADS) seem to influence levels of LCPUFAs on blood and tissue, however studies with pregnats are scarce. In this study, the objective was to evaluate the interaction between PUFAs intake during pregnancy and FADS1 (rs174561) and FADS2 (rs174575 and rs3834358) genes maternal genotypes 1) on the maternal status of plasma LCPUFAs, 2) on the pregnancy duration and 3) on child birth weight. The pregnant women of a prospective cohort of Santo Antônio de Jesus – BA, Brazil, were evaluated. During pregnancy, socioeconomic, health evaluation and blood collection were performed. To estimate PUFA intake, a nutrient-specific food frequency questionaire (FFQ) was developed and validated. Plasma lipids were extracted by Folch method and the fatty acids were identificated by gas chromatography. Genomic DNA extraction was performed from buffy coat. All samples were genotyped with TaqMan® Assay using allelic discrimination on real-time PCR equipment. Pregnancies outcomes were obtained on the Department of Epidemiological Surveillance of the referred city. One-way ANOVA was used to compare the mean of plasma PUFAS n-3 status according to the genotypes at each tertile of α-linolenic (ALA) and Linoleic acid/Linolenic acid (LA:ALA) Intake. Linear regression analysis was used to evaluate gene-diet interaction in the pregnancy duration and birth weight, adjusted for covariates. The linear regression, ajusted to covariable, was used on gene-diet interaction analysis. The minor allele frequency varied from 22,0% to 28,8% on 250 pregnancy women evaluated. Heterozygous pregnants for rs174561 e rs3834458 polimorphisms have a lower intake of LA. Minor allele homozygote pregnants for SNPs FADS1 rs174561 (CC) e FADS2 rs3834458 (DelDel) exhibited higher plasma levels of ALA on the higher tertile of ALA intake and of LA/ALA intake (P < 0,05). For these polymorphisms, EPA and DHA were not affected by the intake of ALA and LA/ALA. For SNP rs174575, minor allele homozygote pregnants exhibited lowest proportions of plasma EPA on second tertile of LA/ALA intake, in comparison with pregnants homozygous for the major allele (p < 0,05). There was no gene-diet interaction in birth weight for the three polymorphisms evaluated. However, in heterozygous women (CG) for the SNP rs174575 the duration of pregnancy was positively associated with ALA intake and negatively with the intake of LA (p <0.05). In conclusion, the increase of ALA intake promotes accumulation of ALA plasma and seems not promote the conversion of LCPUFAs EPA and DHA in pregnants homozygotes for the minor allele for rs174561 and rs3834458. The moderate intake of LA/ALA may also reduce EPA levels in pregnant women who carried the minor allele of polymorphism rs174575. Thus, dietary patterns characterized by higher intake of ALA and LA reduced intake can be beneficial by improving the lipid profile of pregnant women. Heterozygous for the SNP rs174575 (CG) can increase the time of pregnancy in response to higher intake of ALA and lower intake of LA. Regarding the polymorphisms rs174561 and rs3834458, the lack of diet-gene interaction on birth weight and pregnancy duration may have been a reflection of insufficient intake of PUFAs by pregnant women who carried the minor allele, which would hinder the clear observation of causality in relation to outcomes. Probably, the level of PUFA intake by these pregnant women does not promotes evident effects. A hyphotesis for the insufficient PUFAs intake would be an influence of FADS genotypes on taste perception and preference of foods source of PUFAS, that should be investigated in future studies.