title: Lipoprotein-associated phospholipase A2, hormone use, and the risk of ischemic stroke in postmenopausal women.
abstract: Few studies have investigated the role of elevated lipoprotein-associated phospholipase A2 (Lp-PLA(2)) with stroke risk, and those that have are based on small numbers of strokes. No study has evaluated the effect of hormone therapy use on the association of Lp-PLA(2) and stroke. We assessed the relationship between Lp-PLA(2) and the risk of incident ischemic stroke in 929 stroke patients and 935 control subjects in the Hormones and Biomarkers Predicting Stroke Study, a nested case-control study from the Women's Health Initiative Observational Study. Mean (SD) levels of Lp-PLA(2) were significantly higher among case subjects (309.0 [97.1]) than control subjects (296.3 [87.3]; P<0.01). Odds ratio for ischemic stroke for the highest quartile of Lp-PLA(2), compared with lowest, controlling for multiple covariates, was 1.08 (95% CI: 0.75 to 1.55). However, among 1137 nonusers of hormone therapy at baseline, the corresponding odds ratio was 1.55 (95% CI: 1.05 to 2.28),whereas there was no significant association among 737 hormone users (odds ratio: 0.70; 95% CI: 0.42 to 1.17; P for interaction=0.055). Moreover, among nonhormone users, women with high C-reactive protein and high Lp-PLA2 had more than twice the risk of stroke (odds ratio: 2.26; 95% CI: 1.55 to 3.35) compared with women low levels in both biomarkers. Furthermore, different stroke cases were identified as high risk by Lp-PLA(2) rather than by C-reactive protein. Lp-PLA(2) was associated with incident ischemic stroke independently of C-reactive protein and traditional cardiovascular risk factors among nonusers of hormone therapy with highest risk in those who had both high C-reactive protein and high Lp-PLA(2).
authors.affiliation: Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY 10461, USA. smoller@aecom.yu.edu
authors.forename: Sylvia
authors.initials: S
authors.lastname: Wassertheil-Smoller
authors.forename: Charles
authors.initials: C
authors.lastname: Kooperberg
authors.forename: Aileen P
authors.initials: AP
authors.lastname: McGinn
authors.forename: Robert C
authors.initials: RC
authors.lastname: Kaplan
authors.forename: Judith
authors.initials: J
authors.lastname: Hsia
authors.forename: Susan L
authors.initials: SL
authors.lastname: Hendrix
authors.forename: JoAnn E
authors.initials: JE
authors.lastname: Manson
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Berger
authors.forename: Lewis H
authors.initials: LH
authors.lastname: Kuller
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Allison
authors.forename: Alison E
authors.initials: AE
authors.lastname: Baird
mesh_terms: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000097:blood*; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002545:Brain Ischemia / Q000097:blood / Q000453:epidemiology*; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D015914:Estrogen Replacement Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood*; D011237:Predictive Value of Tests; D012307:Risk Factors; D020521:Stroke / Q000097:blood / Q000453:epidemiology*; D016387:Women's Health
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase