Effects of a diet based on the Dietary Guidelines on vascular health and TMAO in women with cardiometabolic risk factors

Background and aims: Recent evidence links trimethylamine oxide (TMAO) to endothelial dysfunction, an early indicator of cardiovascular disease. We aimed to determine whether short-term consumption of a diet patterned after the 2010 Dietary Guidelines for Americans (DGA) would affect endothelial function, plasma TMAO concentrations, and cardiovascular disease risk, differently than a typical American Diet (TAD). Methods and results: An 8-wk controlled feeding trial was conducted in overweight/obese women pre-screened for insulin resistance and/or dyslipidemia. Women were randomized to a DGA or TAD group (n = 22/group). At wk0 (pre-intervention) and wk8 (post-intervention) vascular age was calculated; endothelial function (reactive hyperemia index (RHI)) and augmentation index (AI@75) were measured using EndoPAT, and plasma TMAO was measured by LC-MS/ MS. Vascular age was reduced in DGA at wk8 compared to wk0 but TAD wk8 was not different from wk0 (DGA wk0: 54.2 +/- 4.0 vs. wk8: 50.5 +/- 3.1 (p = 0.05), vs. TAD wk8: 47.7 +/- 2.3). Plasma TMAO concentrations, RHI, and AI@75 were not different between groups or weeks. Conclusion: Consumption of a diet based on the 2010 Dietary Guidelines for Americans for 8 weeks did not improve endothelial function or reduce plasma TMAO. Clinicaltrials.gov: NCT02298725. Published by Elsevier B.V. on behalf of The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. This is an open access article under the CC BY-NC ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).