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Background: The 5-lipoxygenase pathway has been linked to atherothrombotic disease, and a functional tandem repeat polymorphism in the arachidonate lipoxygenase-5 (ALOX-5) gene has been associated with the risk of myocardial infarction (MI). Interestingly, 2 studies have reported an interaction between dietary intakes of the ALOX-5 substrates, arachidonic acid (AA) and eicosapentaenoic acid (EPA), and genotype.Objective: We investigated whether the interactions between the ALOX-5 tandem repeat polymorphism (rs59439148) and adipose tissue AA and EPA were associated with incident MI.Methods: In the Danish Diet, Cancer and Health study, we conducted a case-cohort study including 3089 participants with incident MI identified from national registries and a randomly selected subcohort of 3000 participants. Participants were men and women with a median age of 56 y at baseline and no previous history of cancer. Adipose tissue and blood samples were collected at baseline along with comprehensive questionnaires on lifestyle and demographic data. The ALOX-5 tandem repeat polymorphism was genotyped by multititer plate sequencing. Associations were analyzed by using Cox proportional hazards models.Results: We observed a higher risk of MI for homozygous carriers of the variant alleles in the fifth quintile of AA content than for the reference group with the lowest quintile of AA and carrying the wild-type allele (HR: 3.02; 95% CI: 1.41, 6.44). In contrast, homozygotes for the variant alleles tended to have a higher risk of MI when comparing the lowest quintile of EPA content with the reference group with the highest quintile of EPA and carrying the wild-type allele (HR: 2.15; 95% CI: 0.91, 5.09; P = 0.08). Although our results suggested interactions between the polymorphism and adipose tissue AA and EPA, a quantitative evaluation of interaction by calculating the relative excess risk due to interactions was not significant.Conclusions: Adipose tissue EPA and AA and the ALOX-5 tandem repeat polymorphism did not significantly interact to affect the risk of MI. However, the results should be replicated in larger, heterogeneous populations. [ABSTRACT FROM AUTHOR]

Background: The 5-lipoxygenase pathway (5-LOX) has been implicated in the development of cardiovascular disease and studies have suggested that genetic polymorphisms related to key enzymes in this pathway may confer risk of myocardial infarction (MI). This study investigated the association of pre-selected genetic polymorphisms in four candidate genes of 5-LOX (arachidonate 5-lipoxygenase and its activating protein (ALOX-5 and FLAP), leukotriene A4 hydroxylase (LTA4-H) and leukotriene C4 synthase (LTC4-S)) with incident MI. Methods: In a Danish cohort including 57,053 participants, aged 50–64 at enrolment and recruited from 1993–97, we conducted a case-cohort study including cases with incident MI and a randomly selected sub cohort of 3,000 participants. Cases were identified from national registries through July 2013. A total of 22 SNPs were selected and genotyped using the commercially available KASP™ assay. A tandem-repeat polymorphism, located in the ALOX-5 gene, was genotyped by multi-titre plate sequencing. Haplotypes were inferred using PHASE 2.1. Results: During a median follow-up of 17.0 years we identified 3,089 cases of incident MI. In FLAP, two SNPs were negatively associated with incident MI (rs9551963 & rs17222842) while one SNP (rs2247570) located in LTA4-H, was associated with higher risk of MI when comparing subjects with two copies of the variant allele to homozygotes for the wild type. However, only rs17222842 remained significantly associated with MI after correcting for multiple testing. Furthermore, the promoter polymorphism rs59439148 was associated with risk of MI in men. For male carriers of two variant alleles we found a hazard ratio of 1.63 (95% CI: 1.06;2.52) compared to homozygotes for the wild type. Previously described haplotypes (Hap-A -B, -E and -K) were not associated with MI in our population. Conclusion: In conclusion, some common polymorphisms in the 5-lipoxygenase pathway were modestly associated with incident MI, suggesting a potential role for this pathway in the development of cardiovascular disease. [ABSTRACT FROM AUTHOR]

Several studies have investigated the potential benefits of marine n-3 PUFA in CVD, generally suggesting a lower risk of CHD. However, recent trials have questioned these results. This study investigated the association of fish consumption with dietary intake of marine n-3 PUFA with incident myocardial infarction (MI). In a Danish cohort study, 57 053 subjects between 50 and 64 years of age were enrolled from 1993 to 1997. From national registries, we identified all cases of incident MI. Dietary fish consumption was assessed using a semi-quantitative food questionnaire, including twenty-six questions regarding fish intake. In addition, we calculated the intake of total and individual marine n-3 PUFA. During a median follow-up of 17.0 years, we identified 3089 cases of incident MI. For both men and women, a high intake of fatty fish was inversely related to incident MI. Thus, when comparing the highest and the lowest quintile of fatty fish intake, we found a 12% lower relative risk of MI in men (hazard ratio (HR) 0.88; 95% CI 0.77, 1.00) and a 22% lower relative risk in women (HR 0.78; 95% CI 0.63, 0.96) after adjustments. For women, similar associations were observed for individual and total marine n-3 PUFA. In contrast, intake of lean fish was not associated with MI. In conclusion, incident MI was inversely related to a high intake of fatty fish, but not lean fish. However, test for trends across quintiles was not statistically significant. In general, this study supports the view that consumption of fatty fish may protect against MI. [ABSTRACT FROM AUTHOR]