@article {6613, title = {Circulating omega-6 polyunsaturated fatty acids and total and cause-specific mortality: the Cardiovascular Health Study.}, journal = {Circulation}, volume = {130}, year = {2014}, month = {2014 Oct 7}, pages = {1245-53}, abstract = {

BACKGROUND: Although omega-6 polyunsaturated fatty acids (n-6 PUFA) have been recommended to reduce coronary heart disease (CHD), controversy remains about benefits versus harms, including concerns over theorized proinflammatory effects of n-6 PUFA. We investigated associations of circulating n-6 PUFA including linoleic acid (the major dietary PUFA), γ-linolenic acid, dihomo-γ-linolenic acid, and arachidonic acid, with total and cause-specific mortality in the Cardiovascular Health Study, a community-based U.S. cohort.

METHODS AND RESULTS: Among 2792 participants(aged >=65 years) free of cardiovascular disease at baseline, plasma phospholipid n-6 PUFA were measured at baseline using standardized methods. All-cause and cause-specific mortality, and total incident CHD and stroke, were assessed and adjudicated centrally. Associations of PUFA with risk were assessed by Cox regression. During 34 291 person-years of follow-up (1992-2010), 1994 deaths occurred (678 cardiovascular deaths), with 427 fatal and 418 nonfatal CHD, and 154 fatal and 399 nonfatal strokes. In multivariable models, higher linoleic acid was associated with lower total mortality, with extreme-quintile hazard ratio =0.87 (P trend=0.005). Lower death was largely attributable to cardiovascular disease causes, especially nonarrhythmic CHD mortality (hazard ratio, 0.51; 95\% confidence interval, 0.32-0.82; P trend=0.001). Circulating γ-linolenic acid, dihomo-γ-linolenic acid, and arachidonic acid were not significantly associated with total or cause-specific mortality (eg, for arachidonic acid and CHD death, the extreme-quintile hazard ratio was 0.97; 95\% confidence interval, 0.70-1.34; P trend=0.87). Evaluated semiparametrically, linoleic acid showed graded inverse associations with total mortality (P=0.005). There was little evidence that associations of n-6 PUFA with total mortality varied by age, sex, race, or plasma n-3 PUFA. Evaluating both n-6 and n-3 PUFA, lowest risk was evident with highest levels of both.

CONCLUSIONS: High circulating linoleic acid, but not other n-6 PUFA, was inversely associated with total and CHD mortality in older adults.

}, keywords = {Aged, Arachidonic Acid, Biomarkers, Cohort Studies, Coronary Disease, Fatty Acids, Omega-3, Fatty Acids, Omega-6, Fatty Acids, Unsaturated, Female, Follow-Up Studies, Humans, Linoleic Acid, Male, Prospective Studies, Regression Analysis, Risk Factors, Stroke, Survival Rate, United States}, issn = {1524-4539}, doi = {10.1161/CIRCULATIONAHA.114.011590}, author = {Wu, Jason H Y and Lemaitre, Rozenn N and King, Irena B and Song, Xiaoling and Psaty, Bruce M and Siscovick, David S and Mozaffarian, Dariush} } @article {6567, title = {Genome-wide association study of plasma N6 polyunsaturated fatty acids within the cohorts for heart and aging research in genomic epidemiology consortium.}, journal = {Circ Cardiovasc Genet}, volume = {7}, year = {2014}, month = {2014 Jun}, pages = {321-331}, abstract = {

BACKGROUND: Omega6 (n6) polyunsaturated fatty acids (PUFAs) and their metabolites are involved in cell signaling, inflammation, clot formation, and other crucial biological processes. Genetic components, such as variants of fatty acid desaturase (FADS) genes, determine the composition of n6 PUFAs.

METHODS AND RESULTS: To elucidate undiscovered biological pathways that may influence n6 PUFA composition, we conducted genome-wide association studies and meta-analyses of associations of common genetic variants with 6 plasma n6 PUFAs in 8631 white adults (55\% women) across 5 prospective studies. Plasma phospholipid or total plasma fatty acids were analyzed by similar gas chromatography techniques. The n6 fatty acids linoleic acid (LA), γ-linolenic acid (GLA), dihomo-GLA, arachidonic acid, and adrenic acid were expressed as percentage of total fatty acids. We performed linear regression with robust SEs to test for single-nucleotide polymorphism-fatty acid associations, with pooling using inverse-variance-weighted meta-analysis. Novel regions were identified on chromosome 10 associated with LA (rs10740118; P=8.1{\texttimes}10(-9); near NRBF2), on chromosome 16 with LA, GLA, dihomo-GLA, and arachidonic acid (rs16966952; P=1.2{\texttimes}10(-15), 5.0{\texttimes}10(-11), 7.6{\texttimes}10(-65), and 2.4{\texttimes}10(-10), respectively; NTAN1), and on chromosome 6 with adrenic acid after adjustment for arachidonic acid (rs3134950; P=2.1{\texttimes}10(-10); AGPAT1). We confirmed previous findings of the FADS cluster on chromosome 11 with LA and arachidonic acid, and further observed novel genome-wide significant association of this cluster with GLA, dihomo-GLA, and adrenic acid (P=2.3{\texttimes}10(-72), 2.6{\texttimes}10(-151), and 6.3{\texttimes}10(-140), respectively).

CONCLUSIONS: Our findings suggest that along with the FADS gene cluster, additional genes may influence n6 PUFA composition.

}, keywords = {Adult, Aged, Aged, 80 and over, Aging, Chromosomes, Human, Pair 10, Chromosomes, Human, Pair 16, Chromosomes, Human, Pair 6, Fatty Acid Desaturases, Fatty Acids, Omega-6, Female, Genome-Wide Association Study, Genomics, Heart Diseases, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide, Prospective Studies, Sequence Analysis, DNA}, issn = {1942-3268}, doi = {10.1161/CIRCGENETICS.113.000208}, author = {Guan, Weihua and Steffen, Brian T and Lemaitre, Rozenn N and Wu, Jason H Y and Tanaka, Toshiko and Manichaikul, Ani and Foy, Millennia and Rich, Stephen S and Wang, Lu and Nettleton, Jennifer A and Tang, Weihong and Gu, Xiangjun and Bandinelli, Stafania and King, Irena B and McKnight, Barbara and Psaty, Bruce M and Siscovick, David and Djouss{\'e}, Luc and Chen, Yii-Der Ida and Ferrucci, Luigi and Fornage, Myriam and Mozafarrian, Dariush and Tsai, Michael Y and Steffen, Lyn M} } @article {6685, title = {Genetic loci associated with circulating phospholipid trans fatty acids: a meta-analysis of genome-wide association studies from the CHARGE Consortium.}, journal = {Am J Clin Nutr}, volume = {101}, year = {2015}, month = {2015 Feb}, pages = {398-406}, abstract = {

BACKGROUND: Circulating trans fatty acids (TFAs), which cannot be synthesized by humans, are linked to adverse health outcomes. Although TFAs are obtained from diet, little is known about subsequent influences (e.g., relating to incorporation, metabolism, or intercompetition with other fatty acids) that could alter circulating concentrations and possibly modulate or mediate impacts on health.

OBJECTIVE: The objective was to elucidate novel biologic pathways that may influence circulating TFAs by evaluating associations between common genetic variation and TFA biomarkers.

DESIGN: We performed meta-analyses using 7 cohorts of European-ancestry participants (n = 8013) having measured genome-wide variation in single-nucleotide polymorphisms (SNPs) and circulating TFA biomarkers (erythrocyte or plasma phospholipids), including trans-16:1n-7, total trans-18:1, trans/cis-18:2, cis/trans-18:2, and trans/trans-18:2. We further evaluated SNPs with genome-wide significant associations among African Americans (n = 1082), Chinese Americans (n = 669), and Hispanic Americans (n = 657) from 2 of these cohorts.

RESULTS: Among European-ancestry participants, 31 SNPs in or near the fatty acid desaturase (FADS) 1 and 2 cluster were associated with cis/trans-18:2; a top hit was rs174548 (β = 0.0035, P = 4.90 {\texttimes} 10(-15)), an SNP previously associated with circulating n-3 and n-6 polyunsaturated fatty acid concentrations. No significant association was identified for other TFAs. rs174548 in FADS1/2 was also associated with cis/trans-18:2 in Hispanic Americans (β = 0.0053, P = 1.05 {\texttimes} 10(-6)) and Chinese Americans (β = 0.0028, P = 0.002) but not African Americans (β = 0.0009, P = 0.34); however, in African Americans, fine mapping identified a top hit in FADS2 associated with cis/trans-18:2 (rs174579: β = 0.0118, P = 4.05 {\texttimes} 10(-5)). The association between rs174548 and cis/trans-18:2 remained significant after further adjustment for individual circulating n-3 and n-6 fatty acids, except arachidonic acid. After adjustment for arachidonic acid concentrations, the association between rs174548 and cis/trans-18:2 was nearly eliminated in European-ancestry participants (β-coefficient reduced by 86\%), with similar reductions in Hispanic Americans and Chinese Americans.

CONCLUSIONS: Our findings provide novel evidence for genetic regulation of cis/trans-18:2 by the FADS1/2 cluster and suggest that this regulation may be influenced/mediated by concentrations of arachidonic acid, an n-6 polyunsaturated fat.

}, keywords = {African Americans, Arachidonic Acid, Asian Americans, Biomarkers, European Continental Ancestry Group, Fatty Acids, Omega-6, Gene Frequency, Genetic Association Studies, Genetic Loci, Genotyping Techniques, Humans, Phospholipids, Polymorphism, Single Nucleotide, Trans Fatty Acids}, issn = {1938-3207}, doi = {10.3945/ajcn.114.094557}, author = {Mozaffarian, Dariush and Kabagambe, Edmond K and Johnson, Catherine O and Lemaitre, Rozenn N and Manichaikul, Ani and Sun, Qi and Foy, Millennia and Wang, Lu and Wiener, Howard and Irvin, Marguerite R and Rich, Stephen S and Wu, Hongyu and Jensen, Majken K and Chasman, Daniel I and Chu, Audrey Y and Fornage, Myriam and Steffen, Lyn and King, Irena B and McKnight, Barbara and Psaty, Bruce M and Djouss{\'e}, Luc and Chen, Ida Y-D and Wu, Jason H Y and Siscovick, David S and Ridker, Paul M and Tsai, Michael Y and Rimm, Eric B and Hu, Frank B and Arnett, Donna K} }