title: Calprotectin--a novel marker of obesity.
abstract: BACKGROUND
  The two inflammatory molecules, S100A8 and S100A9, form a heterodimer, calprotectin. Plasma calprotectin levels are elevated in various inflammatory disorders. We hypothesized that plasma calprotectin levels would be increased in subjects with low-grade systemic inflammation i.e. either obese subjects or subjects with type 2 diabetes.
  
  
  RESULTS
  Plasma calprotectin and skeletal muscle S100A8 mRNA levels were measured in a cohort consisting of 199 subjects divided into four groups depending on presence or absence of type 2 diabetes (T2D), and presence or absence of obesity. There was a significant interaction between obesity and T2D (p = 0.012). Plasma calprotectin was increased in obese relative to non-obese controls (p<0.0001), whereas it did not differ between obese and non-obese patients with T2D (p = 0.62). S100A8 mRNA levels in skeletal muscle were not influenced by obesity or T2D. Multivariate regression analysis (adjusting for age, sex, smoking and HOMA2-IR) showed plasma calprotectin to be strongly associated with BMI, even when further adjusted for fitness, CRP, TNF-alpha or neutrophil number.
  
  
  CONCLUSIONS
  Plasma calprotectin is a marker of obesity in individuals without type 2 diabetes.
authors.affiliation: The Centre of Inflammation and Metabolism, Department of Infectious Diseases and Copenhagen Muscle Research Centre, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. bkp@rh.dk
authors.forename: Ole Hartvig
authors.initials: OH
authors.lastname: Mortensen
authors.forename: Anders Rinnov
authors.initials: AR
authors.lastname: Nielsen
authors.forename: Christian
authors.initials: C
authors.lastname: Erikstrup
authors.forename: Peter
authors.initials: P
authors.lastname: Plomgaard
authors.forename: Christian Philip
authors.initials: CP
authors.lastname: Fischer
authors.forename: Rikke
authors.initials: R
authors.lastname: Krogh-Madsen
authors.forename: Birgitte
authors.initials: B
authors.lastname: Lindegaard
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Petersen
authors.forename: Sarah
authors.initials: S
authors.lastname: Taudorf
authors.forename: Bente Klarlund
authors.initials: BK
authors.lastname: Pedersen
mesh_terms: D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000378:metabolism*; D019281:Dimerization; D005260:Female; D006801:Humans; D007249:Inflammation; D039841:Leukocyte L1 Antigen Complex / Q000097:blood* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018482:Muscle, Skeletal / Q000378:metabolism*; D009504:Neutrophils / Q000378:metabolism; D009765:Obesity / Q000097:blood* / Q000378:metabolism*; D012907:Smoking
chemical_list: D039841:Leukocyte L1 Antigen Complex