title: Infections and obesity: A multinational epidemiological study.
abstract: Viral infections have been associated with the aetiology of obesity in animal models. This study investigates the association between 7 serological markers of infections and body mass index (BMI) in a population based sample. Individuals (n=985, mean age 42+/-97 (28-55) y, mean BMI 25.594.2) from Iceland, Sweden and Estonia underwent a structured interview and blood sampling. IgG antibodies were measured against Helicobacter pylori and the cagA protein, hepatitis A virus, Toxoplasma gondii, herpes simplex virus 1, Chlamydia pneumoniae, Epstein-Barr virus and cytomegalovirus. High-sensitive C-reactive protein (CRP) was measured as a marker of systemic inflammation. A significant positive association between being overweight (BMI25 kg/m2) and IgG antibodies was found for Helicobacter pylori (OR 1.86, CI 1.34-2.60) and Chlamydia pneumoniae (OR 1.39, CI 1.03-1.88) and combined seropositivity had synergistic effect (OR 2.54 (1.62-3.97)). CRP was positively related to BMI (pB0.0001), whereas no significant association was found between CRP and IgG antibodies against Helicobacter pylori and/or Chlamydia pneumoniae and CRP. The results suggest that infections with Chlamydia pneumoniae and Helicobacter pylori are both significantly and synergistically associated with overweight and this association is not related to indicators of systemic inflammation.
authors.affiliation: Department of Medicine, Landspitali University Hospital Hringbraut, IS-101, Reykjavik, Iceland. bjarnit@landspitali.is
authors.forename: Bjarni
authors.initials: B
authors.lastname: Thjodleifsson
authors.forename: Isleifur
authors.initials: I
authors.lastname: Olafsson
authors.forename: Davíd
authors.initials: D
authors.lastname: Gislason
authors.forename: Thorarinn
authors.initials: T
authors.lastname: Gislason
authors.forename: Rain
authors.initials: R
authors.lastname: Jögi
authors.forename: Christer
authors.initials: C
authors.lastname: Janson
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood; D000913:Antibodies, Protozoan / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D001424:Bacterial Infections / Q000150:complications / Q000453:epidemiology; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D003141:Communicable Diseases / Q000150:complications* / Q000453:epidemiology*; D004957:Estonia / Q000453:epidemiology; D005260:Female; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000453:epidemiology*; D013548:Sweden / Q000453:epidemiology; D014123:Toxoplasmosis / Q000150:complications / Q000453:epidemiology; D014777:Virus Diseases / Q000150:complications / Q000453:epidemiology
chemical_list: D000907:Antibodies, Bacterial; D000913:Antibodies, Protozoan; D000914:Antibodies, Viral; D007074:Immunoglobulin G; D002097:C-Reactive Protein