title: Post-streptococcal antibodies are associated with metabolic syndrome in a population-based cohort.
abstract: BACKGROUND
  Streptococcal infections are known to trigger autoimmune disorders, affecting millions worldwide. Recently, we found an association between post-streptococcal autoantibodies against Protein Disulphide Isomerase (PDI), an enzyme involved in insulin degradation and insulin resistance. This led us to evaluate associations between post-streptococcal antibodies and metabolic syndrome, as defined by the updated National Cholesterol Education Program definition, 2005.
  
  
  RESULTS
  Metabolic data (HDL, triglycerides, fasting glucose, blood pressure, waist circumference, BMI, smoking), post-streptococcal antibodies (anti-Streptolysin O (ASO) and anti-PDI), and C-reactive protein (CRP, as a general inflammatory marker), were assessed in 1156 participants of the Wisconsin Sleep Cohort Study. Anti-PDI antibodies were found in 308 participants (26.6%), ASO≥100 in 258 (22.3%), and 482 (41.7%) met diagnostic criteria for metabolic syndrome. Anti-PDI antibodies but not ASO were significantly associated with metabolic syndrome [n = 1156, OR 1.463 (95% CI 1.114, 1.920), p = 0.0062; adjusted for age, gender, education, smoking]. Importantly, the anti-PDI-metabolic syndrome association remained significant after adjusting for CRP and fasting insulin.
  
  
  CONCLUSIONS
  Post-streptococcal anti-PDI antibodies are associated with metabolic syndrome regardless of fasting insulin and CRP levels. Whereas these data are in line with a growing body of evidence linking infections, immunity and metabolism, additional studies are necessary to establish the post-streptococcal-metabolic syndrome association.
authors.affiliation: Psychiatry and Behavioral Sciences, Stanford University, Stanford, California, United States of America.
authors.forename: Adi
authors.initials: A
authors.lastname: Aran
authors.forename: Ling
authors.initials: L
authors.lastname: Lin
authors.forename: Laurel Ann
authors.initials: LA
authors.lastname: Finn
authors.forename: Karin
authors.initials: K
authors.lastname: Weiner
authors.forename: Paul
authors.initials: P
authors.lastname: Peppard
authors.forename: Terry
authors.initials: T
authors.lastname: Young
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Mignot
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology*; D015415:Biomarkers / Q000378:metabolism; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood* / Q000150:complications / Q000276:immunology*; D008875:Middle Aged; D009765:Obesity; D013290:Streptococcal Infections / Q000097:blood / Q000150:complications / Q000276:immunology*; D013291:Streptococcus / Q000276:immunology*; D014280:Triglycerides / Q000378:metabolism; D055105:Waist Circumference
chemical_list: D000907:Antibodies, Bacterial; D001323:Autoantibodies; D015415:Biomarkers; D007328:Insulin; D014280:Triglycerides; D002097:C-Reactive Protein