title: Plasma Concentrations of Trimethylamine-N-oxide Are Directly Associated with Dairy Food Consumption and Low-Grade Inflammation in a German Adult Population.
abstract: BACKGROUND
  Trimethylamine-N-oxide (TMAO) is a metabolite of carnitine, choline, and phosphatidylcholine, which is inversely associated with survival of cardiovascular disease (CVD) patients.
  
  
  OBJECTIVE
  We examined the associations of diet with plasma concentrations of TMAO, choline, and betaine and the associations of TMAO with plasma concentrations of various cytokines.
  
  
  METHODS
  Plasma TMAO, choline, and betaine concentrations were measured using LC-high resolution mass spectrometry in 271 participants, ≥18 y old, of the Second Bavarian Food Consumption Survey, conducted in 2002 and 2003. Food consumption was assessed using at least two 24-h dietary recalls. Cytokines were measured in plasma with enzyme-linked immunosorbent assays. Geometric mean concentrations of TMAO, choline, and betaine by categories of meat, dairy food, egg, and fish consumption were computed, adjusted for sex, age, and BMI. Multivariable-adjusted geometric mean concentrations of cytokines [tumor necrosis factor-α (TNF-α), soluble TNF receptors (sTNF-R) p55, sTNF-R p75, interleukin-6 (IL-6), and C-reactive protein (CRP)] were computed by quartiles of TMAO concentration using general linear models.
  
  
  RESULTS
  Meat, egg, or fish consumption was not associated with TMAO, choline, or betaine concentrations (all P-trend ≥ 0.05). With increases in milk and other dairy food consumption, the plasma TMAO concentration increased [geometric mean bottom quartile of milk consumption: 2.08 μM (95% CI: 1.69, 2.57 μM); compared with top quartile: 3.13 μM (95% CI: 2.56, 3.84 μM); P-trend = 0.008]. Participants in the top TMAO quartile had higher plasma concentrations of TNF-α, sTNF-R p55, and sTNF-R p75 than participants in the bottom quartile (percentage difference ranging between 14.4% and 17.3%; all P-trend < 0.05), but there were no differences in plasma concentrations of CRP and IL-6 (all P-trend ≥ 0.05).
  
  
  CONCLUSIONS
  Results of this study conducted among healthy adults from the general population do not indicate a strong effect of diet on plasma concentrations of TMAO, choline, or betaine, with the exception of a positive association between dairy food consumption and plasma TMAO concentrations. Also, plasma TMAO concentrations were positively associated with inflammation. Whether habitual diet is strongly linked to the plasma TMAO concentration, a potential marker of CVD risk, needs to be determined in further studies.
authors.affiliation: Division of Chronic Disease Epidemiology, Epidemiology, Biostatistics and Prevention Institute, and sabine.rohrmann@uzh.ch.
authors.forename: Sabine
authors.initials: S
authors.lastname: Rohrmann
authors.affiliation: Institute of Epidemiology II, Helmholtz Centre Munich, Neuherberg, Germany.
authors.forename: Jakob
authors.initials: J
authors.lastname: Linseisen
authors.affiliation: Institute of Clinical Chemistry, University of Zurich, Zurich Switzerland; and.
authors.forename: Martina
authors.initials: M
authors.lastname: Allenspach
authors.affiliation: Institute of Clinical Chemistry, University of Zurich, Zurich Switzerland; and.
authors.forename: Arnold
authors.initials: A
authors.lastname: von Eckardstein
authors.affiliation: Institute of Clinical Chemistry, University of Zurich, Zurich Switzerland; and.
authors.forename: Daniel
authors.initials: D
authors.lastname: Müller
mesh_terms: D000328:Adult; D000818:Animals; D001622:Betaine / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D002794:Choline / Q000097:blood; D003611:Dairy Products; D004032:Diet; D004034:Diet Surveys; D005247:Feeding Behavior; D005260:Female; D005858:Germany; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000209:etiology; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008744:Methylamines / Q000009:adverse effects / Q000097:blood; D008875:Middle Aged; D008892:Milk; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015850:Interleukin-6; D008744:Methylamines; D047888:Receptors, Tumor Necrosis Factor, Type I; D014409:Tumor Necrosis Factor-alpha; D001622:Betaine; D002097:C-Reactive Protein; C005855:trimethyloxamine; C023336:trimethylamine; D002794:Choline
keywords: Trimethylamine-N-oxide; cheese; inflammation; milk; red meat