title: Chlamydial LPS and high-sensitivity CRP levels in serum are associated with an elevated body mass index in patients with cardiovascular disease.
abstract: OBJECTIVE
  Seropositivity for Chlamydia pneumoniae has been associated with an elevated body mass index (BMI). Our aim was to study if serum chlamydial lipopolysaccharide (cLPS), C. pneumoniae antibodies and high-sensitivity C-reactive protein (hsCRP) levels are associated with BMI.
  
  
  METHODS
  The study population consisted of 174 patients with symptomatic carotid stenosis, abdominal aortic aneurysm or occlusive aortic disease. Information on BMI, diabetes, smoking, hypercholesterolemia, and statin medication was available. Serum C. pneumoniae IgG and IgA antibodies, cLPS, hsCRP and total endotoxin activity (totLPS) were measured.
  
  
  RESULTS
  BMI correlated with cLPS (r = 0.197; P < 0.01) and with hsCRP (rho = 0.195; P < 0.01); in addition, there was a positive correlation between cLPS and hsCRP (rho = 0.499; P < 0.01). A trend of an increasing proportion of C. pneumoniae IgG positivity (titre > or = 64; P = 0.018) and higher serum cLPS (P = 0.01) and hsCRP (P = 0.01) concentrations was observed across the BMI groups (BMI < or = 24.9 kg/m(2), BMI = 25.0-29.9 kg/m(2), and BMI > or = 30.0 kg/m(2)). Among the three BMI groups, 24.6%, 38.8%, and 48.3% were C. pneumoniae IgG-positive and the median (IQR) cLPS concentrations (ng/ml) of the groups were: 92.6 (50.8-167.0), 128.9 (76.4-163.9), and 146.4 (105.8-175.8), respectively. The median (IQR) hsCRP (mg/l) concentrations of the groups were: 1.70 (0.70-3.05) 1.70 (0.80-5.20), and 3.40 (1.45-8.55), respectively. These associations remained statistically significant in a multivariate analysis.
  
  
  CONCLUSIONS
  Elevated serum cLPS levels were associated with an elevated BMI. This is a novel finding and it strengthens the link between chlamydial infection and obesity. A lack of association between totLPS and BMI suggests that the association between infection and an elevated BMI may be specific to certain pathogens.
authors.affiliation: Respiratory Infection Unit, National Public Health Institute, Oulu, Finland. taina.lajunen@ktl.fi
authors.forename: Taina
authors.initials: T
authors.lastname: Lajunen
authors.forename: Pirkka
authors.initials: P
authors.lastname: Vikatmaa
authors.forename: Aini
authors.initials: A
authors.lastname: Bloigu
authors.forename: Tuija
authors.initials: T
authors.lastname: Ikonen
authors.forename: Mauri
authors.initials: M
authors.lastname: Lepäntalo
authors.forename: Pirkko J
authors.initials: PJ
authors.lastname: Pussinen
authors.forename: Pekka
authors.initials: P
authors.lastname: Saikku
authors.forename: Maija
authors.initials: M
authors.lastname: Leinonen
mesh_terms: D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology / Q000382:microbiology* / Q000503:physiopathology*; D023521:Chlamydophila Infections / Q000097:blood / Q000150:complications; D016993:Chlamydophila pneumoniae / Q000276:immunology / Q000378:metabolism*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D008070:Lipopolysaccharides / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000209:etiology
chemical_list: D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D008070:Lipopolysaccharides; D002097:C-Reactive Protein