The Use of Lipoprotein-Associated Phospholipase A2 in a Chinese Population to Predict Cardiovascular Events / 生物医学与环境科学（英文）

Objective@#To explore associations between lipoprotein-associated phospholipase A2 (Lp-PLA2) and the risk of cardiovascular events in a Chinese population, with a long-term follow-up.@*Methods@#A random sample of 2,031 participants (73.6% males, mean age = 60.4 years) was derived from the Asymptomatic Polyvascular Abnormalities Community study (APAC) from 2010 to 2011. Serum Lp-PLA2 levels were determined by enzyme-linked immunosorbent assay (ELISA). The composite endpoint was a combination of first-ever stroke, myocardial infarction (MI) or all-cause death. Lp-PLA2 associations with outcomes were assessed using Cox models.@*Results@#The median Lp-PLA2 level was 141.0 ng/mL. Over a median follow-up of 9.1 years, we identified 389 events (19.2%), including 137 stroke incidents, 43 MIs, and 244 all-cause deaths. Using multivariate Cox regression, when compared with the lowest Lp-PLA2 quartile, the hazard ratios with 95% confidence intervals for developing composite endpoints, stroke, major adverse cardiovascular events, and all-cause death were 1.77 (1.24-2.54), 1.92 (1.03-3.60), 1.69 (1.003-2.84), and 1.94 (1.18-3.18) in the highest quartile, respectively. Composite endpoints in 145 (28.6%) patients occurred in the highest quartile where Lp-PLA2 (159.0 ng/mL) was much lower than the American Association of Clinical Endocrinologists recommended cut-off point, 200 ng/mL.@*Conclusion@#Higher Lp-PLA2 levels were associated with an increased risk of cardiovascular event/death in a middle-aged Chinese population. The Lp-PLA2 cut-off point may be lower in the Chinese population when predicting cardiovascular events.

Lipoprotein associated phospholipase A2 activity & its correlation with oxidized LDL & glycaemic status in early stages of type-2 diabetes mellitus.

Background & objectives: Lipoprotein associated phospholipase A2 (Lp-PLA2) is an important risk predictor of coronary artery disease (CAD). This study was aimed to evaluate Lp-PLA2 activity and oxidized low density lipoprotein (oxLDL) in newly diagnosed patients of type 2 diabetes mellitus and to determine the correlation of Lp-PLA2 activity with oxLDL and plasma glucose levels. Methods: Blood samples were collected in patients with newly diagnosed type 2 diabetes (n=40) before any treatment was started and healthy controls (n=40). These were processed for estimating plasma glucose: fasting and post prandial, ox LDL, and Lp-PLA2 activity. The parameters in the two groups were compared. Correlation between different parameters was calculated by Pearson correlation analysis in both groups. Results: Lp-PLA2 activity (24.48 ± 4.91 vs 18.63 ± 5.29 nmol/min/ml, P<0.001) and oxLDL levels (52.46 ± 40.19 vs 33.26 ± 12.54 μmol/l, P<0.01) were significantly higher in patients as compared to those in controls. Lp-PLA2 activity correlated positively with oxLDL in both controls (r=0.414, P<0.01), as well in patients (r=0.542, P<0.01). A positive correlation between Lp-PLA2 activity and fasting plasma glucose levels was observed only in patients (r=0.348, P<0.05). Interpretation & conclusions: Result of this study implies that higher risk of CAD in patients with diabetes may be due to increase in Lp-PLA2 activity during the early course of the disease. A positive correlation between enzyme activity and fasting plasma glucose indicates an association between hyperglycaemia and increased activity of Lp-PLA2. This may explain a higher occurrence of CAD in patients with diabetes. A positive correlation between oxLDL and Lp-PLA2 activity suggests that Lp-PLA2 activity may be affected by oxLDL also.

Lipoprotein-Associated Phospholipase A2 Is Related to Plaque Stability and Is a Potential Biomarker for Acute Coronary Syndrome

PURPOSE: Plasma lipoprotein-associated phospholipase A2 (Lp-PLA2) binds to low-density lipoprotein. The levels of Lp-PLA2 reflect the plaque burden, and are upregulated in acute coronary syndrome (ACS). We investigated the diagnostic value of Lp-PLA2 levels and found that it might be a potential biomarker for ACS. MATERIALS AND METHODS: We classified 226 study participants into three groups: patients without significant stenosis (control group), patients with significant stenosis with stable angina (SA group), and patients with ACS (ACS group). RESULTS: Lp-PLA2 and high-sensitivity C-reactive protein (hs-CRP) levels were significantly greater in the ACS group than in the SA group (p=0.044 and p=0.029, respectively). Multivariate logistic regression analysis revealed that Lp-PLA2 levels are significantly associated with ACS (odds ratio=1.047, p=0.013). The addition of Lp-PLA2 to the ACS model significantly increased the global chi2 value over traditional risk factors (28.14 to 35.602, p=0.006). The area under the receiver operating characteristic curve for Lp-PLA2 was 0.624 (p=0.004). The addition of Lp-PLA2 level to serum hs-CRP concentration yielded an integrated discrimination improvement of 0.0368 (p=0.0093, standard error: 0.0142) and improved the ability to diagnose ACS. CONCLUSION: Lp-PLA2 levels are related to plaque stability and might be a diagnostic biomarker for ACS.

Taiwanese Female Vegetarians Have Lower Lipoprotein-Associated Phospholipase A2 Compared with Omnivores

PURPOSE: Many studies supported that vegetarians have a lower risk of cardiac diseases and mortality, partly due to better blood pressure and serum cholesterol profiles. However, the inflammatory markers, especially lipoprotein-associated phospholipase A2 (Lp-PLA2), have not been well-studied. This study aimed to compare inflammatory markers and conventional risk factors between vegetarians and omnivores. MATERIALS AND METHODS: One hundred and seventy-three vegetarians and 190 omnivores were studied. Fasting blood samples were obtained to compare levels of glucose, total cholesterol, triacylglycerol, high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol, homocysteine, Lp-PLA2 activity, and high-sensitivity C-reactive protein (hs-CRP). RESULTS: Vegetarians had higher serum levels of the following markers: hs-CRP (1.8 +/- 3.4 vs. 1.2 1.8 mg/L, respectively; p = 0.05), homocysteine (9.39 +/- 3.22 vs. 7.62 +/- 2.41 micromol/L, respectively; p < 0.01), and triacylglycerol (96.91 +/- 59.56 vs. 84.66 +/- 43.24 mg/dL, respectively; p < 0.05). Vegetarians also had lower levels of Lp-PLA2 (18.32 +/- 7.19 10-3 micromol/min/mL vs. 20.22 8.13 10-3 micromol/min/mL; p < 0.05), total cholesterol (180.62 +/- 36.55 mg/dL vs. 192.73 +/- 36.57 mg/dL; p < 0.01), LDL cholesterol (118.15 +/- 32.8 vs. 126.41 +/- 34.28 mg/dL; p < 0.05), and HDL cholesterol (55.59 +/- 13.30 vs. 62.09 +/- 14.52 mg/dL, p < 0.01). Multivariate analyses demonstrated that a vegetarian diet increases the chances for high serum hs-CRP and low Lp-PLA2 activity. CONCLUSION: In addition to lower total cholesterol, LDL-cholesterol, and HDL-cholesterol, Taiwanese female vegetarians have lower serum Lp-PLA2 activity but higher levels of hs-CRP, homocysteine, and triacylglyerol. It might be due to geographic differences of vegetarian diets, and further studies are needed.

Association of Lipoprotein-Associated Phospholipase A2 with Characteristics of Vulnerable Coronary Atherosclerotic Plaques

PURPOSE: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an inflammatory enzyme expressed in atherosclerotic plaques. We investigated the association of circulating Lp-PLA2 with characteristics of vulnerable coronary atherosclerotic plaques. MATERIALS AND METHODS: We recruited 113 patients with either unstable angina (UA, n=59) and stable angina (SA, n=54) by coronary angiography. Thirty-six healthy subjects served as controls. Intravascular ultrasound (IVUS) was used to evaluate the characteristics of coronary atherosclerotic plaque, and serum Lp-PLA2 concentration was measured as well. RESULTS: Lp-PLA2 concentration was significantly higher in both UA and SA patients [(396+/-36) microg/L and (321+/-39) microg/L, respectively] compared with the controls [(127+/-49) microg/L, p<0.01], and higher in UA than SA group. IVUS findings showed that remodeling index (RI) (0.91+/-0.15 vs. 0.85+/-0.11, p=0.005) and eccentricity index (EI) (0.73+/-0.16 vs. 0.65+/-0.22, p=0.039) were larger in UA than in SA group, and fibrous caps were thicker in SA than UA group [(0.91+/-0.23) mm vs. (0.63+/-0.21) mm, p=0.032]. Moreover, Lp-PLA2 correlated positively with EI (r=0.439, p<0.01) and RI (r=0.592, p<0.05) in UA group. There was an inverse relationship between Lp-PLA2 and fibrous cap thickness in both UA (r=-0.587, p<0.001) and SA (r=-0.318, p<0.05) groups. The independent risk factors in UA group were Lp-PLA2 (OR=1.055, 95% CI: 1.03-1.08, p=0.013), LDL-cholesterol (OR=0.032, 95% CI: 0.00-0.05, p=0.041) and fibrous cap thickness (OR=0.008, 95% CI: 0.00-0.45, p=0.019). Lp-PLA2 was strongly associated with both EI and fibrous cap thickness in both groups. CONCLUSION: Serum level of Lp-PLA2 is associated with both eccentricity index and fibrous cap thickness in both UA and SA groups. Elevated levels of circulating Lp-PLA2 might to be a strong risk factor and more serious for unstable angina than stable angina.