title: Dietary fat, abdominal obesity and smoking modulate the relationship between plasma complement component 3 concentrations and metabolic syndrome risk.
abstract: OBJECTIVE
  Chronic inflammation plays a role in the pathogenesis of metabolic syndrome (MetS) and cardiovascular disease (CVD). Complement component 3 (C3) is a novel cardiometabolic risk factor. Whether dietary fat intake modulates MetS risk conferred by elevated C3 concentrations is unknown. Our objective is to investigate the relationship between C3 concentrations and risk of the MetS and its phenotypes, and to further examine whether dietary fat intake modulates these relationships.
  
  
  METHODS
  Biochemical, dietary and lifestyle measurements were determined in the LIPGENE-SU.VI.MAX study of MetS cases and matched controls (n=1754).
  
  
  RESULTS
  Elevated C3 concentrations (>median) were associated with increased risk of impaired insulin sensitivity [OR 1.78, CI 1.34-2.36, P<0.0001], insulin resistance [OR 1.73, CI 1.31-2.89, P=0.0001], abdominal obesity [OR 2.15, CI 1.43-3.24, P=0.0002] and low HDL cholesterol [OR 1.40, CI 1.05-1.86, P=0.02] compared to low C3 concentrations. Increased MetS risk conferred by elevated C3 concentrations [OR 3.11, 95% CI 2.52-3.82, P<0.0001] was further accentuated among high dietary fat consumers [OR 4.80, 95% CI 2.77-8.33, P<0.0001] (particularly of saturated [OR 4.05, 95% CI 2.33-7.05, P<0.0001] and monounsaturated fat [OR 4.48, 95% CI 2.62-7.56, P<0.0001]), and smokers [OR 3.83, 95% CI 2.12-6.94, P<0.0001], however this effect was abolished in abdominally lean individuals [OR 1.46, 95% CI 0.69-3.14, P=0.33].
  
  
  CONCLUSIONS
  Dietary fat (intake and composition), abdominal obesity and smoking modulate the relationship between elevated plasma C3 concentrations and MetS risk.
authors.affiliation: Nutrigenomics Research Group, UCD Conway Institute, UCD School of Public Health and Population Science, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Phillips
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Kesse-Guyot
authors.forename: Namanjeet
authors.initials: N
authors.lastname: Ahluwalia
authors.forename: Ross
authors.initials: R
authors.lastname: McManus
authors.forename: Serge
authors.initials: S
authors.lastname: Hercberg
authors.forename: Denis
authors.initials: D
authors.lastname: Lairon
authors.forename: Richard
authors.initials: R
authors.lastname: Planells
authors.forename: Helen M
authors.initials: HM
authors.lastname: Roche
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D008076:Cholesterol, HDL / Q000097:blood; D003176:Complement C3 / Q000032:analysis*; D004041:Dietary Fats / Q000009:adverse effects*; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000453:epidemiology* / Q000276:immunology; D008875:Middle Aged; D056128:Obesity, Abdominal / Q000097:blood / Q000453:epidemiology* / Q000276:immunology; D016017:Odds Ratio; D010641:Phenotype; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D008076:Cholesterol, HDL; D003176:Complement C3; D004041:Dietary Fats; D007328:Insulin