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

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 > or =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>3mg/l, compared to Lp-PLA(2) tertile 1 and CRP<1mg/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 ( approximately 20% excess risk) and activity added excess risk for CVD death ( approximately 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.