title: Interaction between soluble thrombomodulin and intercellular adhesion molecule-1 in predicting risk of coronary heart disease.
abstract: BACKGROUND
  Results from previous ARIC (Atherosclerosis Risk In Communities) analyses indicate that soluble intercellular adhesive molecule-1 (sICAM) and soluble thrombomodulin (sTM) levels are associated with risk of coronary heart disease (CHD) in an opposite direction. A high sICAM level increases the risk of CHD, whereas a high level of sTM has a lower risk of CHD. It was unclear whether there was an interaction between sTM and sICAM.
  
  
  RESULTS
  Using a nested case-cohort design, we measured sTM and sICAM in 317 incident CHD cases and 726 non-cases from the ARIC participants. Consistent with our previous reports, sICAM values in the upper versus the lower tertile increased the risk of CHD event by approximately 2-fold (95% confidence interval [CI], 1.46 to 2.87) whereas sTM values in the lower versus the upper tertile increased CHD risk by approximately 4-fold (95% CI, 2.80 to 5.74). Interaction between these 2 parameters was determined by weighted Cox proportional hazard regression. A significant interaction (P=0.038) was noted. Combinatorial analysis shows a significant increase in CHD risk ratio (RR) (4.66, 95% CI, 1.89 to 11.46) of the lower sTM/upper sICAM group versus the upper sTM/lower sICAM group. Individuals whose sTM values were in the upper tertile had a RR below 1, even when sICAM were in the upper tertile. The RR of lower tertile sTM was increased by sICAM in a tertile-dependent manner.
  
  
  CONCLUSIONS
  Weighted Cox proportional hazard analysis shows a significant interaction between sTM and sICAM in predicting risk of CHD event. Combinatorial analysis reveals that an upper tertile sICAM had a significant increase in the risk of a CHD event only when sTM was in the lower tertile.
authors.affiliation: Vascular Biology Research Center and Department of Internal Medicine, University of Texas-Houston Health Science Center, Houston, Tex, USA. Kenneth.K.Wu@uth.tmc.edu
authors.forename: Kenneth K
authors.initials: KK
authors.lastname: Wu
authors.forename: Nena
authors.initials: N
authors.lastname: Aleksic
authors.forename: Christie M
authors.initials: CM
authors.lastname: Ballantyne
authors.forename: Chul
authors.initials: C
authors.lastname: Ahn
authors.forename: Harinder
authors.initials: H
authors.lastname: Juneja
authors.forename: Eric
authors.initials: E
authors.lastname: Boerwinkle
mesh_terms: D016022:Case-Control Studies; D003327:Coronary Disease / Q000453:epidemiology*; D005260:Female; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D018180:Thrombomodulin / Q000097:blood*
chemical_list: D018180:Thrombomodulin; D018799:Intercellular Adhesion Molecule-1