title: Lower serum paraoxonase-1 activity is related to higher serum amyloid a levels in metabolic syndrome.
abstract: OBJECTIVE
  High-density lipoproteins (HDL) contain the anti-oxidative enzyme, paraoxonase-1 (PON-1), which is important for atheroprotection. The acute phase reactant, serum amyloid A (SAA), an HDL-associated apolipoprotein, may impair PON-1 activity, whereas SAA and PON-1 are reciprocally regulated in response to acute inflammatory stimuli. The relationship of serum PON-1 activity with SAA during low-grade chronic inflammation is unclear. Here we tested the extent to which low serum PON-1 activity is related to high SAA levels in subjects with and without metabolic syndrome (MetS).
  
  
  METHODS
  In 19 nondiabetic subjects with MetS and 67 subjects without MetS, serum PON-1, assayed as its arylesterase activity, and SAA were measured together with plasma lipids and lipoproteins, high-sensitive C-reactive protein (hs-CRP) and insulin resistance (homeostasis model assessment (HOMA(ir)).
  
  
  RESULTS
  PON-1 activity was decreased (p=0.023), whereas SAA levels were increased (p=0.042) in MetS subjects, coinciding with higher hs-CRP levels and HOMA(ir) values. Multiple linear regression analysis revealed that age- and gender-adjusted PON-1 activity was related inversely to SAA (β=-0.256, p=0.020) after adjustment for MetS, or alternatively for hs-CRP and HOMA(ir) (β=-0.271, p=0.049).
  
  
  CONCLUSIONS
  Decreased serum PON-1 activity in MetS may in part be attributable to higher SAA levels. We suggest that higher SAA levels contribute to impaired HDL anti-oxidative function in MetS via an effect on PON-1 regulation.
authors: Department of Endocrinology, University of Groningen and University Medical Center Groningen, Groningen, The Netherlands.
authors: Paul Jan Willem Herman
authors: PJ
authors: Kappelle
authors: Johan
authors: J
authors: Bijzet
authors: Bouke Pier
authors: BP
authors: Hazenberg
authors: Robin Pieter Frank
authors: RP
authors: Dullaart
mesh_terms: D000368:Aged; D043303:Aryldialkylphosphatase / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D005260:Female; D006801:Humans; D016014:Linear Models; D008075:Lipoproteins, HDL / Q000097:blood; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood*; D008875:Middle Aged; D000685:Serum Amyloid A Protein / Q000378:metabolism*
chemical_list: D008075:Lipoproteins, HDL; D000685:Serum Amyloid A Protein; D002097:C-Reactive Protein; D002784:Cholesterol; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human