title: Neopterin and kynurenine-tryptophan ratio as predictors of coronary events in older adults, the Hordaland Health Study.
abstract: BACKGROUND
  Immune system activation is involved in atherosclerosis. Neopterin production and tryptophan catabolism through the kynurenine pathway, measured by the kynurenine-tryptophan ratio (KTR), are induced by interferon gamma, thus both are considered markers of cell mediated immune activation. This study prospectively investigated their predictive value on acute coronary events among Norwegian community-dwelling older adults without previous coronary heart disease.
  
  
  METHODS
  1112 men and 1631 women, 71-74 years old were examined during 1997-99 as part of the Hordaland Health Study. They were followed until an acute coronary event (defined as unstable angina, non-fatal or fatal acute myocardial infarction or sudden death) or December 31, 2006. Kaplan-Meier hazard curves were constructed for quartiles of plasma neopterin and KTR. Cox proportional hazards models adjusted for sex, body mass index, smoking, hypertension, renal function and cholesterol were used to examine the relation between neopterin and KTR quartiles and the study endpoint.
  
  
  RESULTS
  Median (interquartile range) values were 8.6 (7.2-10.4) nmol/L for neopterin and 25.8 (25.3-31.1) nmol/μmol for KTR. During the follow up, 265 participants had at least one acute coronary event. Increased baseline levels of plasma neopterin and KTR were associated with continuous increased risk of developing the study endpoint (P-values for trend <0.001 and 0.019, respectively). Adjusted hazard ratios comparing the fourth quartile to the first were 1.65 (95% CI; 1.11-2.47; P=0.013) for neopterin and 1.57 (95% CI 1.03-2.39; P=0.036) for KTR.
  
  
  CONCLUSIONS
  Plasma neopterin and KTR levels predict acute coronary events in older adults without previous coronary heart disease.
authors: Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway. Electronic address: gerhard.sulo@isf.uib.no.
authors: Gerhard
authors: G
authors: Sulo
authors: Stein E
authors: SE
authors: Vollset
authors: Ottar
authors: O
authors: Nygård
authors: Øivind
authors: Ø
authors: Midttun
authors: Per Magne
authors: PM
authors: Ueland
authors: Simone J P M
authors: SJ
authors: Eussen
authors: Eva R
authors: ER
authors: Pedersen
authors: Grethe S
authors: GS
authors: Tell
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D003324:Coronary Artery Disease / Q000097:blood* / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys / Q000379:methods; D006801:Humans; D007737:Kynurenine / Q000097:blood*; D008297:Male; D019798:Neopterin / Q000097:blood*; D009664:Norway / Q000453:epidemiology; D011446:Prospective Studies; D014364:Tryptophan / Q000097:blood*
chemical_list: D015415:Biomarkers; D007737:Kynurenine; D019798:Neopterin; D014364:Tryptophan
keywords: Coronary artery disease; Epidemiology; Immune system; Kynurenine; Neopterin; Tryptophan ratio