title: The association between inflammatory biomarkers and metabolically healthy obesity depends of the definition used.
abstract: OBJECTIVE
  To assess the distribution of interleukin (IL)-1β, IL-6, tumour necrosis factor (TNF)-α and C-reactive protein (CRP) according to the different definitions of metabolically healthy obesity (MHO).
  
  
  METHODS
  A total of 881 obese (body mass index (BMI) > or =30 kg/m2) subjects derived from the population-based CoLaus Study participated in this study. MHO was defined using six sets of criteria including different combinations of waist, blood pressure, total high-density lipoprotein cholesterol or low-density lipoprotein -cholesterol, triglycerides, fasting glucose, homeostasis model, high-sensitivity CRP, and personal history of cardiovascular, respiratory or metabolic diseases. IL-1β, IL-6 and TNF-α were assessed by multiplexed flow cytometric assay. CRP was assessed by immunoassay.
  
  
  RESULTS
  On bivariate analysis some, but not all, definitions of MHO led to significantly lower levels of IL-6, TNF-α and CRP compared with non-MH obese subjects. Most of these differences became nonsignificant after multivariate analysis. An posteriori analysis showed a statistical power between 9 and 79%, depending on the inflammatory biomarker and MHO definition considered. Further increasing sample size to overweight+obese individuals (BMI > or =25 kg/m2, n=2917) showed metabolically healthy status to be significantly associated with lower levels of CRP, while no association was found for IL-1β. Significantly lower IL-6 and TNF-α levels were also found with some but not all MHO definitions, the differences in IL-6 becoming nonsignificant after adjusting for abdominal obesity or percent body fat.
  
  
  CONCLUSIONS
  MHO individuals present with decreased levels of CRP and, depending on MHO definition, also with decreased levels in IL-6 and TNF-α. Conversely, no association with IL-1β levels was found.
authors.affiliation: Institute of Social and Preventive Medicine, University of Lausanne, Lausanne, Switzerland. Pedro-Manuel.Marques-Vidal@chuv.ch
authors.forename: P
authors.initials: P
authors.lastname: Marques-Vidal
authors.forename: S
authors.initials: S
authors.lastname: Velho
authors.forename: D
authors.initials: D
authors.lastname: Waterworth
authors.forename: G
authors.initials: G
authors.lastname: Waeber
authors.forename: R
authors.initials: R
authors.lastname: von Känel
authors.forename: P
authors.initials: P
authors.lastname: Vollenweider
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood*; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000150:complications; D053583:Interleukin-1beta / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D016014:Linear Models; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000097:blood* / Q000150:complications; D015995:Prevalence; D014280:Triglycerides / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015415:Biomarkers; D053583:Interleukin-1beta; D015850:Interleukin-6; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D014280:Triglycerides; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein