Maternal and Offspring Fatty Acid Desaturase Variants, Prenatal DHA Supplementation, and Dietary n–6:n–3 Fatty Acid Ratio in Relation to Cardiometabolic Health in Mexican Children

Single nucleotide polymorphisms (SNPs) in fatty acid desaturase (FADS) genes may modify dietary fatty acid requirements and influence cardiometabolic health (CMH). We evaluated the role of selected variants in maternal and offspring FADS genes on offspring CMH at age 11y and assessed interactions of genotype with diet quality and prenatal docosahexaenoic acid (DHA) supplementation. We used data from offspring (n=203) born to women who participated in a randomized controlled trial of DHA supplementation (400 mg/d) from mid-gestation through delivery. We generated a metabolic syndrome (MetS) score from body mass index, HDL cholesterol, triglycerides, systolic blood pressure and fasting glucose and identified six distinct haplotypes from five offspring FADS SNPs. Dietary n-6:n-3 fatty acid ratios were derived from 24-hour recall data (n=141). We used generalized linear models to test associations of offspring diet and FADS haplotypes with MetS score and interactions of maternal and offspring FADS SNP rs174602 with prenatal treatment group and dietary n-6:n-3 ratio on MetS score. Associations between FADS haplotypes and MetS score were null. Offspring SNP rs174602 did not modify the association of prenatal DHA supplementation with MetS score. Among children with TT or TC genotype for SNP rs174602 (n = 88), those in the highest n-6:n-3 ratio tertile (> 8.61) had higher MetS score relative to the lowest tertile (< 6.67) (Δ= 0.36; 95% CI: 0.03, 0.69). Among children with CC genotype (n = 53), those in the highest n-6:n-3 ratio tertile had lower MetS score relative to the lowest tertile (Δ= -0.23; 95% CI: -0.61, 0.16). There was evidence of interaction of offspring FADS SNP rs174602 with current dietary PUFA intake, but not with prenatal DHA supplementation, on MetS score. Further studies may help determine the utility of targeted supplementation strategies and dietary recommendations based on genetic profile. This trial was registered at clinicaltrials.gov (NCT00646360).