Association of lipoprotein-associated phospholipase A₂ mass and activity with calcified coronary plaque in young adults: The CARDIA study

Objective - To examine the association of lipoprotein-associated phospholipase A₂ (Lp-PLA₂) mass and activity with calcified coronary plaque in young adults. Methods and Results - Nested case-control study among CARDIA participants at the year 15 examination (2000 to 2001, 33 to 45 years old). Cases (n=266) were those with and controls (n=266) those without evidence of calcified coronary plaque by computed tomography matched 1:1 on sex and race. Lp-PLA₂ mass and activity were significantly higher in cases (296±101 ng/mL and 36.4±12.3 nmol/mL per minute) than in controls (267±80 ng/mL and 32.9±11.8 nmol/mL per minute). In age-adjusted conditional logistic regression, the odds ratio (OR) of calcified coronary plaque per 1 standard deviation (SD) increment was 1.40 (95% CI, 1.17 to 1.67) and 1.39 (95% CI, 1.14 to 1.70) for Lp-PLA ₂ mass and activity, respectively. After adjusting for multiple covariates including low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides, and C-reactive protein, a statistically significant association remained for Lp-PLA₂ mass (OR, 1.28; 95% CI, 1.03 to 1.60) but not for activity (OR, 1.09; 95% CI, 0.84 to 1.42). No evidence was found for interaction between Lp-PLA₂ mass or activity with LDL-C as predictors of calcified coronary plaque. Conclusion - An independent association of Lp-PLA₂ mass with calcified coronary plaque existed in young adults. Therefore, Lp-PLA₂ mass may be a useful marker of subclinical cardiovascular risk.