title: Lipoprotein-associated phospholipase A2 is associated with atherosclerotic stroke risk: the Northern Manhattan Study.
abstract: BACKGROUND
  Lipoprotein-associated phospholipase A2 (LpPLA2) levels are associated with stroke, though whether this extends to all populations and stroke subtypes is unknown.
  
  
  METHODS
  Serum samples from stroke-free community participants in the Northern Manhattan Study were assayed for LpPLA2 mass and activity. Participants were followed annually for stroke. Cox-proportional-hazard models were fitted to estimate hazard-ratios and 95% confidence intervals (HR, 95% CI) for the association of LpPLA2 levels with ischemic stroke (IS), after adjusting for demographic and medical risk factors.
  
  
  RESULTS
  Serum samples were available in 1946 participants, of whom 151 (7.8%) experienced a first IS during median follow-up 11 years. Mean age was 69 (SD 10), 35.6% were men, 20% non-Hispanic Whites, 22% non-Hispanic Blacks, and 55% Hispanics. LpPLA2 mass and activity levels were not associated with overall IS risk. LpPLA2 mass but not activity levels were associated with strokes due to large artery atherosclerosis (LAA; adjusted HR per SD 1.55, 95% CI 1.17-2.04). There was a dose-response relationship with LAA (compared to first quartile, 2nd quartile HR = 1.43, 95% CI 0.23-8.64; 3rd quartile HR = 4.47, 95% CI 0.93-21.54; 4th quartile HR = 5.07, 95% CI 1.07-24.06). The associations between LpPLA2-mass and LAA-stroke risk differed by race-ethnicity (p = 0.01); LpPLA2-mass was associated with increased risk of LAA among non-Hispanic Whites (adjusted HR per SD 1.44, 95% CI 0.98-2.11), but not other race-ethnic groups.
  
  
  CONCLUSIONS
  LpPLA2-mass levels were associated with risk of atherosclerotic stroke among non-Hispanic White participants, but not in other race-ethnic groups in the cohort. Further study is needed to confirm these race-ethnic differences and the reasons for them.
authors.affiliation: Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, United States of America ; Department of Neurology, University Hospital of Zurich, Switzerland.
authors.forename: Mira
authors.initials: M
authors.lastname: Katan
authors.affiliation: Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, United States of America.
authors.forename: Yeseon P
authors.initials: YP
authors.lastname: Moon
authors.affiliation: Department of Biostatistics, Mailman School of Public Health, Columbia University New York, New York, United States of America.
authors.forename: Myunghee C
authors.initials: MC
authors.lastname: Paik
authors.affiliation: diaDexus, Inc., San Francisco, California, United States of America.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Wolfert
authors.affiliation: Department of Neurology, Miller School of Medicine, University of Miami, Miami, Florida, United States of America ; Departments of Epidemiology and Human Genetics, Miller School of Medicine, University of Miami, Miami, Florida, United States of America.
authors.forename: Ralph L
authors.initials: RL
authors.lastname: Sacco
authors.affiliation: Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York, United States of America ; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York, United States of America.
authors.forename: Mitchell S V
authors.initials: MS
authors.lastname: Elkind
mesh_terms: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; D000368:Aged; D050197:Atherosclerosis / Q000150:complications* / Q000201:enzymology* / Q000453:epidemiology / Q000208:ethnology; D002545:Brain Ischemia / Q000201:enzymology / Q000208:ethnology / Q000209:etiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009518:New York / Q000208:ethnology; D054467:Phospholipases A2 / Q000378:metabolism*; D012307:Risk Factors; D020521:Stroke / Q000201:enzymology* / Q000453:epidemiology / Q000208:ethnology / Q000209:etiology*
chemical_list: D054467:Phospholipases A2; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; C526684:PLA2G7 protein, human