@article {1238, title = {Circulating palmitoleic acid and risk of metabolic abnormalities and new-onset diabetes.}, journal = {Am J Clin Nutr}, volume = {92}, year = {2010}, month = {2010 Dec}, pages = {1350-8}, abstract = {

BACKGROUND: Animal experiments suggest that circulating palmitoleic acid (cis-16:1n-7) from adipocyte de novo fatty acid synthesis may directly regulate insulin resistance and metabolic dysregulation.

OBJECTIVE: We investigated the independent determinants of circulating palmitoleate in free-living humans and whether palmitoleate is related to lower metabolic risk and the incidence of diabetes.

DESIGN: In a prospective cohort of 3630 US men and women in the Cardiovascular Health Study, plasma phospholipid fatty acids, anthropometric variables, blood lipids, inflammatory markers, and glucose and insulin concentrations were measured between 1992 and 2006 by using standardized methods. Independent determinants of plasma phospholipid palmitoleate and relations of palmitoleate with metabolic risk factors were investigated by using multivariable-adjusted linear regression. Relations with incident diabetes (296 incident cases) were investigated by using Cox proportional hazards.

RESULTS: The mean ({\textpm} SD) palmitoleate value was 0.49 {\textpm} 0.20\% (range: 0.11-2.55\%) of total fatty acids. Greater body mass index, carbohydrate intake, protein intake, and alcohol use were each independent lifestyle correlates of higher palmitoleate concentrations. In multivariable analyses that adjusted for these factors and other potential confounders, higher palmitoleate concentrations were independently associated with lower LDL cholesterol (P < 0.001), higher HDL cholesterol (P < 0.001), lower total:HDL-cholesterol ratio (P = 0.04), and lower fibrinogen (P < 0.001). However, palmitoleate was also associated with higher triglycerides (P < 0.001) and (in men only) with greater insulin resistance (P < 0.001). Palmitoleate was not significantly associated with incident diabetes.

CONCLUSIONS: Adiposity (energy imbalance), carbohydrate consumption, and alcohol use-even within typical ranges-are associated with higher circulating palmitoleate concentrations. Circulating palmitoleate is robustly associated with multiple metabolic risk factors but in mixed directions, perhaps related to divergent lifestyle determinants or endogenous sources (liver, adipose tissue) of fatty acid synthesis.

}, keywords = {Aged, Aged, 80 and over, Alcohol Drinking, Body Mass Index, Cholesterol, Cholesterol, HDL, Diabetes Mellitus, Diet, Dietary Carbohydrates, Fatty Acids, Monounsaturated, Female, Fibrinogen, Humans, Insulin Resistance, Life Style, Lipids, Male, Proportional Hazards Models, Prospective Studies, Risk Factors, Sex Factors, Triglycerides}, issn = {1938-3207}, doi = {10.3945/ajcn.110.003970}, author = {Mozaffarian, Dariush and Cao, Haiming and King, Irena B and Lemaitre, Rozenn N and Song, Xiaoling and Siscovick, David S and Hotamisligil, G{\"o}khan S} } @article {1257, title = {Trans-palmitoleic acid, metabolic risk factors, and new-onset diabetes in U.S. adults: a cohort study.}, journal = {Ann Intern Med}, volume = {153}, year = {2010}, month = {2010 Dec 21}, pages = {790-9}, abstract = {

BACKGROUND: Palmitoleic acid (cis-16:1n-7), which is produced by endogenous fat synthesis, has been linked to both beneficial and deleterious metabolic effects, potentially confounded by diverse determinants and tissue sources of endogenous production. Trans-palmitoleate (trans-16:1n-7) represents a distinctly exogenous source of 16:1n-7, unconfounded by endogenous synthesis or its determinants, that may be uniquely informative.

OBJECTIVE: To investigate whether circulating trans-palmitoleate is independently related to lower metabolic risk and incident type 2 diabetes.

DESIGN: Prospective cohort study from 1992 to 2006.

SETTING: Four U.S. communities.

PATIENTS: 3736 adults in the Cardiovascular Health Study.

MEASUREMENTS: Anthropometric characteristics and levels of plasma phospholipid fatty acids, blood lipids, inflammatory markers, and glucose-insulin measured at baseline in 1992 and dietary habits measured 3 years earlier. Multivariate-adjusted models were used to investigate how demographic, clinical, and lifestyle factors independently related to plasma phospholipid trans-palmitoleate; how trans-palmitoleate related to major metabolic risk factors; and how trans-palmitoleate related to new-onset diabetes (304 incident cases). Findings were validated for metabolic risk factors in an independent cohort of 327 women.

RESULTS: In multivariate analyses, whole-fat dairy consumption was most strongly associated with higher trans-palmitoleate levels. Higher trans-palmitoleate levels were associated with slightly lower adiposity and, independently, with higher high-density lipoprotein cholesterol levels (1.9\% across quintiles; P = 0.040), lower triglyceride levels (-19.0\%; P < 0.001), a lower total cholesterol-HDL cholesterol ratio (-4.7\%; P < 0.001), lower C-reactive protein levels (-13.8\%; P = 0.05), and lower insulin resistance (-16.7\%, P < 0.001). Trans-palmitoleate was also associated with a substantially lower incidence of diabetes, with multivariate hazard ratios of 0.41 (95\% CI, 0.27 to 0.64) and 0.38 (CI, 0.24 to 0.62) in quintiles 4 and 5 versus quintile 1 (P for trend < 0.001). Findings were independent of estimated dairy consumption or other fatty acid dairy biomarkers. Protective associations with metabolic risk factors were confirmed in the validation cohort.

LIMITATION: Results could be affected by measurement error or residual confounding.

CONCLUSION: Circulating trans-palmitoleate is associated with lower insulin resistance, presence of atherogenic dyslipidemia, and incident diabetes. Our findings may explain previously observed metabolic benefits of dairy consumption and support the need for detailed further experimental and clinical investigation.

PRIMARY FUNDING SOURCE: National Heart, Lung, and Blood Institute and National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health.

}, keywords = {Adiposity, Aged, C-Reactive Protein, Cholesterol, Cholesterol, HDL, Dairy Products, Diabetes Mellitus, Type 2, Fatty Acids, Monounsaturated, Feeding Behavior, Female, Humans, Incidence, Insulin Resistance, Male, Prospective Studies, Risk Factors, Triglycerides, United States}, issn = {1539-3704}, doi = {10.7326/0003-4819-153-12-201012210-00005}, author = {Mozaffarian, Dariush and Cao, Haiming and King, Irena B and Lemaitre, Rozenn N and Song, Xiaoling and Siscovick, David S and Hotamisligil, G{\"o}khan S} } @article {6663, title = {Plasma phospholipid very-long-chain saturated fatty acids and incident diabetes in older adults: the Cardiovascular Health Study.}, journal = {Am J Clin Nutr}, volume = {101}, year = {2015}, month = {2015 May}, pages = {1047-54}, abstract = {

BACKGROUND: Circulating saturated fatty acids (SFAs) are integrated biomarkers of diet and metabolism that may influence the pathogenesis of diabetes. In epidemiologic studies, circulating levels of palmitic acid (16:0) are associated with diabetes; however, very-long-chain SFAs (VLSFAs), with 20 or more carbons, differ from palmitic acid in their biological activities, and little is known of the association of circulating VLSFA with diabetes.

OBJECTIVE: By using data from the Cardiovascular Health Study, we examined the associations of plasma phospholipid VLSFA levels measured at baseline with subsequent incident diabetes.

DESIGN: A total of 3179 older adults, with a mean age of 75 y at study baseline (1992-1993), were followed through 2011. We used multiple proportional hazards regression to examine the associations of arachidic acid (20:0), behenic acid (22:0), and lignoceric acid (24:0) with diabetes.

RESULTS: Baseline levels of each VLSFA were cross-sectionally associated with lower triglyceride levels and lower circulating palmitic acid. We identified 284 incident diabetes cases during follow-up. Compared with the lowest quartile, levels of arachidic acid in the highest quartile of the fatty acid distribution were associated with a 47\% lower risk of diabetes (95\% CI: 23\%, 63\%; P-trend: <0.001), after adjustment for demographics, lifestyle factors, and clinical conditions. In analogous comparisons, levels of behenic and lignoceric acid were similarly associated with 33\% (95\% CI: 6\%, 53\%; P-trend: 0.02) and 37\% (95\% CI: 11\%, 55\%; P-trend: 0.01) lower diabetes risk, respectively. Adjustment for triglycerides and palmitic acid attenuated the associations toward the null, and only the association of arachidic acid remained statistically significant (32\% lower risk for fourth vs. first quartile; P-trend: 0.04).

CONCLUSIONS: These results suggest that circulating VLSFAs are associated with a lower risk of diabetes, and these associations may be mediated by lower triglycerides and palmitic acid. The study highlights the need to distinguish the effects of different SFAs and to explore determinants of circulating VLSFAs. This trial was registered at clinicaltrials.gov as NCT00005133.

}, keywords = {Aged, Aged, 80 and over, Biomarkers, Cross-Sectional Studies, Diabetes Mellitus, Diet, Eicosanoic Acids, Fatty Acids, Fatty Acids, Nonesterified, Female, Follow-Up Studies, Humans, Incidence, Male, Observational Studies as Topic, Palmitic Acid, Phospholipids, Prospective Studies, Risk Factors, Triglycerides}, issn = {1938-3207}, doi = {10.3945/ajcn.114.101857}, author = {Lemaitre, Rozenn N and Fretts, Amanda M and Sitlani, Colleen M and Biggs, Mary L and Mukamal, Kenneth and King, Irena B and Song, Xiaoling and Djouss{\'e}, Luc and Siscovick, David S and McKnight, Barbara and Sotoodehnia, Nona and Kizer, Jorge R and Mozaffarian, Dariush} } @article {6951, title = {Interaction of methylation-related genetic variants with circulating fatty acids on plasma lipids: a meta-analysis of 7 studies and methylation analysis of 3 studies in the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium.}, journal = {Am J Clin Nutr}, volume = {103}, year = {2016}, month = {2016 Feb}, pages = {567-78}, abstract = {

BACKGROUND: DNA methylation is influenced by diet and single nucleotide polymorphisms (SNPs), and methylation modulates gene expression.

OBJECTIVE: We aimed to explore whether the gene-by-diet interactions on blood lipids act through DNA methylation.

DESIGN: We selected 7 SNPs on the basis of predicted relations in fatty acids, methylation, and lipids. We conducted a meta-analysis and a methylation and mediation analysis with the use of data from the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) consortium and the ENCODE (Encyclopedia of DNA Elements) consortium.

RESULTS: On the basis of the meta-analysis of 7 cohorts in the CHARGE consortium, higher plasma HDL cholesterol was associated with fewer C alleles at ATP-binding cassette subfamily A member 1 (ABCA1) rs2246293 (β = -0.6 mg/dL, P = 0.015) and higher circulating eicosapentaenoic acid (EPA) (β = 3.87 mg/dL, P = 5.62 {\texttimes} 10(21)). The difference in HDL cholesterol associated with higher circulating EPA was dependent on genotypes at rs2246293, and it was greater for each additional C allele (β = 1.69 mg/dL, P = 0.006). In the GOLDN (Genetics of Lipid Lowering Drugs and Diet Network) study, higher ABCA1 promoter cg14019050 methylation was associated with more C alleles at rs2246293 (β = 8.84\%, P = 3.51 {\texttimes} 10(18)) and lower circulating EPA (β = -1.46\%, P = 0.009), and the mean difference in methylation of cg14019050 that was associated with higher EPA was smaller with each additional C allele of rs2246293 (β = -2.83\%, P = 0.007). Higher ABCA1 cg14019050 methylation was correlated with lower ABCA1 expression (r = -0.61, P = 0.009) in the ENCODE consortium and lower plasma HDL cholesterol in the GOLDN study (r = -0.12, P = 0.0002). An additional mediation analysis was meta-analyzed across the GOLDN study, Cardiovascular Health Study, and the Multi-Ethnic Study of Atherosclerosis. Compared with the model without the adjustment of cg14019050 methylation, the model with such adjustment provided smaller estimates of the mean plasma HDL cholesterol concentration in association with both the rs2246293 C allele and EPA and a smaller difference by rs2246293 genotypes in the EPA-associated HDL cholesterol. However, the differences between 2 nested models were NS (P > 0.05).

CONCLUSION: We obtained little evidence that the gene-by-fatty acid interactions on blood lipids act through DNA methylation.

}, keywords = {Apolipoproteins E, ATP Binding Cassette Transporter 1, Cholesterol, HDL, Cohort Studies, Diet, DNA Methylation, Eicosapentaenoic Acid, Epigenesis, Genetic, Fatty Acids, Gene Expression Regulation, Humans, Lipids, Polymorphism, Single Nucleotide, Promoter Regions, Genetic, Triglycerides}, issn = {1938-3207}, doi = {10.3945/ajcn.115.112987}, author = {Ma, Yiyi and Follis, Jack L and Smith, Caren E and Tanaka, Toshiko and Manichaikul, Ani W and Chu, Audrey Y and Samieri, Cecilia and Zhou, Xia and Guan, Weihua and Wang, Lu and Biggs, Mary L and Chen, Yii-der I and Hernandez, Dena G and Borecki, Ingrid and Chasman, Daniel I and Rich, Stephen S and Ferrucci, Luigi and Irvin, Marguerite Ryan and Aslibekyan, Stella and Zhi, Degui and Tiwari, Hemant K and Claas, Steven A and Sha, Jin and Kabagambe, Edmond K and Lai, Chao-Qiang and Parnell, Laurence D and Lee, Yu-Chi and Amouyel, Philippe and Lambert, Jean-Charles and Psaty, Bruce M and King, Irena B and Mozaffarian, Dariush and McKnight, Barbara and Bandinelli, Stefania and Tsai, Michael Y and Ridker, Paul M and Ding, Jingzhong and Mstat, Kurt Lohmant and Liu, Yongmei and Sotoodehnia, Nona and Barberger-Gateau, Pascale and Steffen, Lyn M and Siscovick, David S and Absher, Devin and Arnett, Donna K and Ordovas, Jose M and Lemaitre, Rozenn N} }