@article {8041, title = {Fatty acid biomarkers of dairy fat consumption and incidence of type 2 diabetes: A pooled analysis of prospective cohort studies.}, journal = {PLoS Med}, volume = {15}, year = {2018}, month = {2018 10}, pages = {e1002670}, abstract = {

BACKGROUND: We aimed to investigate prospective associations of circulating or adipose tissue odd-chain fatty acids 15:0 and 17:0 and trans-palmitoleic acid, t16:1n-7, as potential biomarkers of dairy fat intake, with incident type 2 diabetes (T2D).

METHODS AND FINDINGS: Sixteen prospective cohorts from 12 countries (7 from the United States, 7 from Europe, 1 from Australia, 1 from Taiwan) performed new harmonised individual-level analysis for the prospective associations according to a standardised plan. In total, 63,682 participants with a broad range of baseline ages and BMIs and 15,180 incident cases of T2D over the average of 9 years of follow-up were evaluated. Study-specific results were pooled using inverse-variance-weighted meta-analysis. Prespecified interactions by age, sex, BMI, and race/ethnicity were explored in each cohort and were meta-analysed. Potential heterogeneity by cohort-specific characteristics (regions, lipid compartments used for fatty acid assays) was assessed with metaregression. After adjustment for potential confounders, including measures of adiposity (BMI, waist circumference) and lipogenesis (levels of palmitate, triglycerides), higher levels of 15:0, 17:0, and t16:1n-7 were associated with lower incidence of T2D. In the most adjusted model, the hazard ratio (95\% CI) for incident T2D per cohort-specific 10th to 90th percentile range of 15:0 was 0.80 (0.73-0.87); of 17:0, 0.65 (0.59-0.72); of t16:1n7, 0.82 (0.70-0.96); and of their sum, 0.71 (0.63-0.79). In exploratory analyses, similar associations for 15:0, 17:0, and the sum of all three fatty acids were present in both genders but stronger in women than in men (pinteraction < 0.001). Whereas studying associations with biomarkers has several advantages, as limitations, the biomarkers do not distinguish between different food sources of dairy fat (e.g., cheese, yogurt, milk), and residual confounding by unmeasured or imprecisely measured confounders may exist.

CONCLUSIONS: In a large meta-analysis that pooled the findings from 16 prospective cohort studies, higher levels of 15:0, 17:0, and t16:1n-7 were associated with a lower risk of T2D.

}, keywords = {Aged, Australia, Biomarkers, Dairy Products, Diabetes Mellitus, Type 2, Dietary Fats, Europe, Fatty Acids, Fatty Acids, Monounsaturated, Female, Humans, Incidence, Male, Middle Aged, Prospective Studies, Sex Factors, Taiwan, United States}, issn = {1549-1676}, doi = {10.1371/journal.pmed.1002670}, author = {Imamura, Fumiaki and Fretts, Amanda and Marklund, Matti and Ardisson Korat, Andres V and Yang, Wei-Sin and Lankinen, Maria and Qureshi, Waqas and Helmer, Catherine and Chen, Tzu-An and Wong, Kerry and Bassett, Julie K and Murphy, Rachel and Tintle, Nathan and Yu, Chaoyu Ian and Brouwer, Ingeborg A and Chien, Kuo-Liong and Frazier-Wood, Alexis C and Del Gobbo, Liana C and Djouss{\'e}, Luc and Geleijnse, Johanna M and Giles, Graham G and de Goede, Janette and Gudnason, Vilmundur and Harris, William S and Hodge, Allison and Hu, Frank and Koulman, Albert and Laakso, Markku and Lind, Lars and Lin, Hung-Ju and McKnight, Barbara and Rajaobelina, Kalina and Riserus, Ulf and Robinson, Jennifer G and Samieri, Cecilia and Siscovick, David S and Soedamah-Muthu, Sabita S and Sotoodehnia, Nona and Sun, Qi and Tsai, Michael Y and Uusitupa, Matti and Wagenknecht, Lynne E and Wareham, Nick J and Wu, Jason HY and Micha, Renata and Forouhi, Nita G and Lemaitre, Rozenn N and Mozaffarian, Dariush} } @article {9182, title = {Dietary Meat, Trimethylamine N-Oxide-Related Metabolites, and Incident Cardiovascular Disease Among Older Adults: The Cardiovascular Health Study.}, journal = {Arterioscler Thromb Vasc Biol}, volume = {42}, year = {2022}, month = {2022 09}, pages = {e273-e288}, abstract = {

BACKGROUND: Effects of animal source foods (ASF) on atherosclerotic cardiovascular disease (ASCVD) and underlying mechanisms remain controversial. We investigated prospective associations of different ASF with incident ASCVD and potential mediation by gut microbiota-generated trimethylamine N-oxide, its L-carnitine-derived intermediates γ-butyrobetaine and crotonobetaine, and traditional ASCVD risk pathways.

METHODS: Among 3931 participants from a community-based US cohort aged 65+ years, ASF intakes and trimethylamine N-oxide-related metabolites were measured serially over time. Incident ASCVD (myocardial infarction, fatal coronary heart disease, stroke, other atherosclerotic death) was adjudicated over 12.5 years median follow-up. Cox proportional hazards models with time-varying exposures and covariates examined ASF-ASCVD associations; and additive hazard models, mediation proportions by different risk pathways.

RESULTS: After multivariable-adjustment, higher intakes of unprocessed red meat, total meat, and total ASF associated with higher ASCVD risk, with hazard ratios (95\% CI) per interquintile range of 1.15 (1.01-1.30), 1.22 (1.07-1.39), and 1.18 (1.03-1.34), respectively. Trimethylamine N-oxide-related metabolites together significantly mediated these associations, with mediation proportions (95\% CI) of 10.6\% (1.0-114.5), 7.8\% (1.0-32.7), and 9.2\% (2.2-44.5), respectively. Processed meat intake associated with a nonsignificant trend toward higher ASCVD (1.11 [0.98-1.25]); intakes of fish, poultry, and eggs were not significantly associated. Among other risk pathways, blood glucose, insulin, and C-reactive protein, but not blood pressure or blood cholesterol, each significantly mediated the total meat-ASCVD association.

CONCLUSIONS: In this large, community-based cohort, higher meat intake associated with incident ASCVD, partly mediated by microbiota-derived metabolites of L-carnitine, abundant in red meat. These novel findings support biochemical links between dietary meat, gut microbiome pathways, and ASCVD.

}, keywords = {Animals, Atherosclerosis, Cardiovascular Diseases, Carnitine, Humans, Meat, Methylamines, Risk Factors}, issn = {1524-4636}, doi = {10.1161/ATVBAHA.121.316533}, author = {Wang, Meng and Wang, Zeneng and Lee, Yujin and Lai, Heidi T M and de Oliveira Otto, Marcia C and Lemaitre, Rozenn N and Fretts, Amanda and Sotoodehnia, Nona and Budoff, Matthew and DiDonato, Joseph A and McKnight, Barbara and Tang, W H Wilson and Psaty, Bruce M and Siscovick, David S and Hazen, Stanley L and Mozaffarian, Dariush} }