title: Lipoprotein-associated phospholipase A2, homocysteine, and Alzheimer's disease.
abstract: BACKGROUND
  Lipoprotein-associated phospholipase A2 (Lp-PLA2) and homocysteine (Hcy) have been linked to inflammation and Alzheimer's disease (AD). Using a case-control design, we examined their independent effects and interactions with cardiovascular disease equivalent (CVDE), on AD risk.
  
  
  METHODS
  AD cases and controls were from the Texas Alzheimer's Research and Care Consortium study. Lp-PLA2 was determined using the PLAC test (diaDexus, Inc), and Hcy by recombinant cycling assay (Roche Hitachi 911). Logistic regression was used to predict AD case status. We assayed for Lp-PLA2 in the brain tissue of cases and controls.
  
  
  RESULTS
  AD case status was independently associated with Lp-PLA2 and Hcy above the median (odds ratio [OR] = 1.91; 95% confidence interval [CI] = 1.22-2.97; P < .001 and OR = 1.81; 95% CI = 1.16-2.82; P = .009, respectively). Lp-PLA2, but not Hcy, interacted with CVDE to increase risk. Lp-PLA2 was absent from the brain tissue in both groups.
  
  
  CONCLUSIONS
  Higher Lp-PLA2 and Hcy are independently associated with AD. The association of Lp-PLA2 with AD may be mediated through vascular damage.
authors.affiliation: Alzheimer's Disease and Memory Disorders Center, Department of Neurology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Rachelle S
authors.initials: RS
authors.lastname: Doody
authors.affiliation: Epidemiologic Expertise, Houston, TX, USA.
authors.forename: Jasenka
authors.initials: J
authors.lastname: Demirovic
authors.affiliation: Section of Atherosclerosis and Lipoprotein Research, Department of Medicine, Baylor College of Medicine, and Methodist DeBakey Heart and Vascular Center, Houston, TX, USA.
authors.forename: Christie M
authors.initials: CM
authors.lastname: Ballantyne
authors.affiliation: Department of Biostatistics, University of Texas Health Science Center, School of Public Health, Houston, TX, USA.
authors.forename: Wenyaw
authors.initials: W
authors.lastname: Chan
authors.affiliation: Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Barber
authors.affiliation: Department of Pathology, The Methodist Hospital, Houston, TX, USA.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Powell
authors.affiliation: Department of Family and Community Medicine, Baylor College of Medicine, Houston, TX, USA; Department of Neurology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Valory
authors.initials: V
authors.lastname: Pavlik
keywords: Alzheimer's disease; Biomarkers; Dementia; Homocysteine; Lp-PLA2