title: Plasma dimethylglycine and risk of incident acute myocardial infarction in patients with stable angina pectoris.
abstract: OBJECTIVE
  Dimethylglycine is linked to lipid metabolism, and increased plasma levels may be associated with adverse prognosis in patients with coronary artery disease. We evaluated the relationship between plasma dimethylglycine and risk of incident acute myocardial infarction in a large prospective cohort of patients with stable angina pectoris, of whom approximately two thirds were participants in a B-vitamin intervention trial. Model discrimination and reclassification when adding plasma dimethylglycine to established risk factors were obtained. We also explored temporal changes and the test-retest reliability of plasma dimethylglycine.
  
  
  RESULTS
  Four thousand one hundred fifty patients (72% men; median age 62 years) were included. Plasma dimethylglycine was associated with several traditional coronary artery disease risk factors. During a median follow-up of 4.6 years, 343 (8.3%) patients experienced an acute myocardial infarction. The hazard ratio (95% confidence interval) for acute myocardial infarction was 1.95 (1.42-2.68; P<0.001) when comparing plasma dimethylglycine quartile 4 to 1 in a Cox regression model adjusted for age, sex, and fasting status. Adjusting for traditional coronary artery disease risk factors only slightly modified the estimates, which were particularly strong among nonsmokers and among patients with serum triglyceride or apolipoprotein B100 levels ≤ median (P for interaction=0.004, 0.004, and 0.03, respectively). Plasma dimethylglycine improved discrimination and reclassification and had high test-retest reliability.
  
  
  CONCLUSIONS
  Plasma dimethylglycine is independently related to incident acute myocardial infarction and enhances risk prediction in patients with stable angina pectoris. Our results motivate further studies on the relationship between 1-carbon metabolism and atherothrombosis. A potential interplay with lipid and energy metabolism merits particular attention.
authors.affiliation: Department of Clinical Science, University of Bergen, Bergen, Norway. gard.frodahl.svingen@helse-bergen.no
authors.forename: Gard Frodahl Tveitevåg
authors.initials: GF
authors.lastname: Svingen
authors.forename: Per Magne
authors.initials: PM
authors.lastname: Ueland
authors.forename: Eva Kristine Ringdal
authors.initials: EK
authors.lastname: Pedersen
authors.forename: Hall
authors.initials: H
authors.lastname: Schartum-Hansen
authors.forename: Reinhard
authors.initials: R
authors.lastname: Seifert
authors.forename: Marta
authors.initials: M
authors.lastname: Ebbing
authors.forename: Kjetil Halvorsen
authors.initials: KH
authors.lastname: Løland
authors.forename: Grethe S
authors.initials: GS
authors.lastname: Tell
authors.forename: Ottar
authors.initials: O
authors.lastname: Nygård
mesh_terms: D000328:Adult; D000368:Aged; D060050:Angina, Stable / Q000097:blood* / Q000453:epidemiology*; D015415:Biomarkers / Q000097:blood; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D050356:Lipid Metabolism / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000453:epidemiology*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012521:Sarcosine / Q000031:analogs & derivatives* / Q000097:blood; D013927:Thrombosis / Q000097:blood / Q000453:epidemiology
chemical_list: D015415:Biomarkers; C025138:dimethylglycine; D012521:Sarcosine
keywords: acute myocardial infarction; angina pectoris; biological markers; lipids; smoking