Lipoprotein-associated phospholipase A 2 (Lp-PLA 2) and risk of cardiovascular disease in older adults: Results from the Cardiovascular Health Study

Abstract

Objective To examine associations between lipoprotein-associated phospholipase A 2 (Lp-PLA 2) antigen level (mass) and enzymatic activity (activity) and cardiovascular disease (CVD) in older adults. Methods We examined associations of Lp-PLA 2 mass and activity with incident myocardial infarction (MI; n = 508), stroke ( n = 565) and CVD death ( n = 665) using Cox regressions adjusted for age, sex, ethnicity and CVD risk factors in 3949 older adults, aged ≥65 years at baseline, from the Cardiovascular Health Study (CHS). Results Lp-PLA 2 was associated with incident CVD events in these older adults. Hazard ratios (95% confidence intervals) for highest versus lowest tertiles of Lp-PLA 2 mass were 1.49 (1.19–1.85) for MI, 1.21 (0.98–1.49) for stroke and 1.11 (0.92–1.33) for CVD death. The highest tertile of Lp-PLA 2 activity was associated with MI (1.36; 1.09–1.70) and CVD death (1.23; 1.02–1.50). Combined Lp-PLA 2 tertile 3 and CRP > 3 mg/l, compared to Lp-PLA 2 tertile 1 and CRP < 1 mg/l, was associated with MI (2.29; 1.49–3.52) for Lp-PLA 2 mass and MI (1.66; 1.10–2.51) and CVD death (1.57; 1.08–2.26) for activity. For MI, both mass and activity added excess risk to elevated CRP alone (∼20% excess risk) and activity added excess risk for CVD death (∼12%). Conclusion Lp-PLA 2 mass and activity were associated with incident CVD events in older adults in CHS. Lp-PLA 2 and CRP were independent and additive in prediction of events. While associations were modest, these results support further exploration of Lp-PLA 2 to identify older individuals at risk for CVD.