title: Circulating levels of interleukin 6 soluble receptor and its natural antagonist, sgp130, and the risk of myocardial infarction.
abstract: OBJECTIVE
  To investigate the association between circulating levels of the soluble interleukin 6 receptor (sIL6R) and the soluble gp130 (sgp130) with myocardial infarction (MI) and to explore the potential interaction between sIL6R and sgp130 in this association.
  
  
  METHODS
  Study population is the Stockholm Heart Epidemiology Program (SHEEP), a population-based case-control study. SIL6R (ng/mL) and sgp130 (ng/mL) levels were measured in serum samples from 682 and 664 MI cases and 1103 and 1062 controls, respectively. Odds ratios (with 95% CIs) for MI were calculated using unconditional logistic regression. We adjusted for age, sex, hospital catchment area (crude) and for hypertension, diabetes, hypercholesterolemia, body mass index and smoking (adjusted model). Synergy index (S) and attributable proportion (AP) were estimated as measures of biological interaction.
  
  
  RESULTS
  Elevated concentrations of sIL6R (>75th percentile value) were associated with an increased occurrence of MI (compared to ≤75th percentile), with an adjusted OR of 1.4 (95% CI, 1.1-1.8). Very high (>90th percentile value) levels of sgp130 were associated with a reduced occurrence of MI [OR 0.7 (95% CI, 0.5-0.9)] (adjusted). There was an indication of a possible interaction between high sIL6R and low sgp130 (adjusted S score 1.7, 95% CI = 0.5-6.1; AP 0.19, 95% CI = -0.2-0.5), suggesting that low sgp130 levels may synergize with high sIL6R levels to increase risk of MI.
  
  
  CONCLUSIONS
  sIL6R and sgp130 had opposing associations with MI. Indeed, circulating sgp130 levels may modify the association of elevated sIL6R levels with MI.
authors.affiliation: Unit of Cardiovascular Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Sweden.
authors.forename: Ilais
authors.initials: I
authors.lastname: Moreno Velásquez
authors.affiliation: Unit of Cardiovascular Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Sweden.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Golabkesh
authors.affiliation: Unit of Cardiovascular Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Källberg
authors.affiliation: Unit of Cardiovascular Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Leander
authors.affiliation: Unit of Cardiovascular Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Sweden; Dept of Cardiology, Karolinska University Hospital, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: de Faire
authors.affiliation: Unit of Cardiovascular Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Sweden; Division of Cardiovascular Medicine, Dept of Clinical Sciences, Danderyd University Hospital Stockholm, Sweden. Electronic address: Bruna.Gigante@ki.se.
authors.forename: Bruna
authors.initials: B
authors.lastname: Gigante
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D050822:Cytokine Receptor gp130 / Q000097:blood*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D016017:Odds Ratio; D011379:Prognosis; D065840:Protective Factors; D019947:Receptors, Interleukin-6 / Q000097:blood*; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; C508603:IL6R protein, human; C494199:IL6ST protein, human; D019947:Receptors, Interleukin-6; D050822:Cytokine Receptor gp130
keywords: Biomarkers; Interleukin 6 receptor; Myocardial infarction; Soluble gp130; sIL6R