Lipoprotein-associated Phospholipase A2 Mass Research Articles

Whole genome sequencing based analysis of inflammation biomarkers in the Trans-Omics for Precision Medicine (TOPMed) consortium.

Inflammation biomarkers can provide valuable insight into the role of inflammatory processes in many diseases and conditions. Sequencing based analyses of such biomarkers can also serve as an exemplar of the genetic architecture of quantitative traits. To evaluate the biological insight, which can be provided by a multi-ancestry, whole-genome based association study, we performed a comprehensive analysis of 21 inflammation biomarkers from up to 38 465 individuals with whole-genome sequencing from the Trans-Omics for Precision Medicine (TOPMed) program (with varying sample size by trait, where the minimum sample size was n = 737 for MMP-1). We identified 22 distinct single-variant associations across 6 traits-E-selectin, intercellular adhesion molecule 1, interleukin-6, lipoprotein-associated phospholipase A2 activity and mass, and P-selectin-that remained significant after conditioning on previously identified associations for these inflammatory biomarkers. We further expanded upon known biomarker associations by pairing the single-variant analysis with a rare variant set-based analysis that further identified 19 significant rare variant set-based associations with 5 traits. These signals were distinct from both significant single variant association signals within TOPMed and genetic signals observed in prior studies, demonstrating the complementary value of performing both single and rare variant analyses when analyzing quantitative traits. We also confirm several previously reported signals from semi-quantitative proteomics platforms. Many of these signals demonstrate the extensive allelic heterogeneity and ancestry-differentiated variant-trait associations common for inflammation biomarkers, a characteristic we hypothesize will be increasingly observed with well-powered, large-scale analyses of complex traits.

Gender-related and PUFA-related differences in lipoprotein-associated phospholipase A2 levels in patients with type 2 diabetes and atherosclerotic cardiovascular disease.

Lipoprotein-associated phospholipase A2 (Lp-PLA2) may play an important role in the development of atherosclerotic cardiovascular disease (ASCVD). Increased plasma levels of Lp-PLA2 may predict future cardiovascular (CV) events in type 2 diabetes (T2D). The potential beneficial effects of polyunsaturated fatty acids (PUFA) on ASCVD have been widely investigated. However, the impact of different PUFA concentrations on Lp-PLA2 remains uncertain. We sought to determine the intergender differences in a population of patients with both T2D and ASCVD regarding Lp-PLA2 mass and the association between Lp-PLA2 mass and plasma levels of PUFA. In this cross-sectional study, we measured the Lp-PLA2 mass, PUFA concentrations and inflammatory markers in 74 patients (49 males and 25 females) with T2D and ASCVD. In this very high-risk population, males had, on average, 33.6% higher levels of Lp-PLA2 than females. The Lp-PLA2 mass was positively associated with interleukin 6 (IL-6) (r = 0.27, p = 0.019), creatinine (r = 0.29, p = 0.03) and triglyceride levels (r = 0.41, p = 0.002). Additionally, male gender and higher levels of triglycerides, leptin, oxidized low-density lipoprotein (oxLDL), and intercellular adhesion molecule 1 (ICAM-1) were independent predictors for an increased Lp-PLA2. Moreover, arachidonic acid (AA) negatively correlated with Lp-PLA2 (r = -0.26, p = 0.024), which was especially apparent in the female subgroup. In the population of patients with ASCVD and T2D, males present with higher plasma levels of Lp-PLA2 than females. Additionally, higher plasma levels of AA were associated with lower Lp-PLA2 levels. Our findings support the utilization of Lp-PLA2 as a novel biomarker in ASCVD risk assessment in a very high CV risk population.

The effects of fatty acid-based dietary interventions on circulating bioactive lipid levels as intermediate biomarkers of health, cardiovascular disease, and cardiovascular disease risk factors: a systematic review and meta-analysis of randomized clinical trials.

Dietary fatty acids (FAs), primarily n-3 polyunsaturated FAs, have been associated with enrichment of the circulating bioactive lipidome and changes in the enzymatic precursor lipoprotein-associated phospholipase A2 (Lp-PLA2) mass; however, the magnitude of this effect remains unclear. The aim of this systematic review and meta-analysis was to evaluate the effect of different dietary FAs on the bioactive lipid profile of healthy participants and those with cardiovascular disease (CVD) and CVD risk factors. PubMed, SCOPUS and the Cochrane Library databases were searched for relevant articles published between October 2010 and May 2022. Data were screened for relevance and then retrieved in full and evaluated for eligibility by 2 reviewers independently. The net difference in the bioactive lipid mean values between the endpoint and the baseline, and the corresponding SDs or SEs, were used for the qualitative synthesis. For the meta-analysis, a fixed-effects model was used. Twenty-seven randomized clinical trials (representing >2560 participants) were included. Over 78% of the enrolled participants had ≥1 associated CVD risk factor, whereas <22% were healthy. In the meta-analysis, marine n-3 supplements (dose range, 0.37-1.9 g/d) significantly increased pro-inflammatory lysophosphatidylcholines (lyso-PCs; for lyso-PC(16:0): mean, +0.52 [95% confidence interval (CI), 0.02-1.01] µM; for lyso-PC(18:0): mean, +0.58 [95%CI, 0.09-1.08] µM) in obese participants. Additionally, n-3 supplementation (1-5.56 g/d) decreased plasma Lp-PLA2 mass, a well-known inflammation marker, in healthy (-0.35 [95%CI, -0.59 to -0.10] ng/mL), dyslipidemic (-0.36 [95%CI, -0.47 to -0.25] ng/mL), and stable coronary artery disease participants (-0.52 [95%CI, -0.91 to -0.12] ng/mL). Daily n-3 provided as EPA+DHA supplements and consumed from 1 to 6 months reduced plasma Lp-PLA2 mass in healthy participants and those with CVD and CVD risk factors, suggesting an anti-inflammatory effect. However, the saturated lyso-PC response to n-3 was impaired in obese participants. PROSPERO registration no. CRD42021218335.

Biological Properties and Clinical Significance of Lipoprotein-Associated Phospholipase A2 in Ischemic Stroke.

Ischemic stroke, which occurs following blockage of the blood supply to the brain, is a leading cause of death worldwide. Its main cause is atherosclerosis, a disease of the arteries characterized by the deposition of plaques of fatty material on the inner artery walls. Multiple proteins involved in the inflammation response have been identified as diagnosing biomarkers of ischemic stroke. One of these is lipoprotein-associated phospholipase A2 (Lp-PLA2), an enzyme that can hydrolyze circulating oxidized phospholipids, generating proinflammatory lysophosphatidylcholine and promoting the development of atherosclerosis. In the last two decades, a number of studies have revealed that both the concentration and the activity of Lp-PLA2 are independent biomarkers of ischemic stroke. The US Food and Drug Administration (FDA) has approved two tests to determine Lp-PLA2 mass and activity for predicting stroke. In this review, we summarize the biological properties of Lp-PLA2, the detection sensitivity and limitations of Lp-PLA2 measurement, the clinical significance and association of Lp-PLA2 in ischemic stroke, and the prospects of therapeutic inhibition of Lp-PLA2 as an intervention and treatment.

Interleukin-6 and YKL-40 predicted recurrent stroke after ischemic stroke or TIA: analysis of 6 inflammation biomarkers in a prospective cohort study

ObjectiveContribution of individual and combined inflammatory markers in prognosis after stroke was still undefined. We aimed to investigate the association of systemic and local vascular inflammatory markers and recurrent stroke as well as impact on poor functional outcome.MethodsIn this pre-specified substudy of the Third China National Stroke Registry (CNSR-III), 10,472 consecutive acute ischemic stroke or TIA patients with available centralized-measured levels of Interleukin-6 (IL-6), high sensitive C-reactive protein (hsCRP), IL-1 receptor antagonist (IL-1Ra), lipoprotein-associated phospholipase A2 mass (Lp-PLA2) and activity (Lp-PLA2-A), and YKL-40 from 171 sites were enrolled. The primary outcomes consisted of stroke recurrence and poor functional outcome defined as modified Rankin Scale (mRS) score of 2–6 within 1 year.ResultsThere were 1026 (9.8%) and 2395 (23.4%) patients with recurrent stroke and poor functional outcome within 1 year. The highest quartiles of IL-6 (adjusted HR, 1.36; 95% CI 1.13–1.64; P = 0.001), hsCRP (adjusted HR, 1.41; 95% CI 1.17–1.69; P = 0.0003) and YKL-40 (adjusted HR, 1.28; 95% CI 1.06–1.56; P = 0.01) were associated with increased risk of recurrent stroke; and the highest quartiles of IL-6 (adjusted OR 1.93; 95% CI 1.64–2.27; P < 0.0001), IL-1Ra (adjusted OR 1.60; 95% CI 1.37–1.87; P < 0.0001), hsCRP (adjusted OR 1.60; 95% CI 1.37–1.86; P < 0.0001) and YKL-40 (adjusted OR 1.21; 95% CI 1.03–1.42; P = 0.02) were correlated with increased risk of poor functional outcome. In the multivariate stepwise regression analysis including all markers with backward selection, elevated levels of IL-6 or YKL-40 were associated with recurrent stroke (IL6: OR, 1.34; 95% CI 1.19–1.52; P < 0.0001; YKL-40: OR, 1.01; 95% CI 1.01–1.03; P = 0.004) and poor functional outcome (IL6: OR, 1.68; 95% CI 1.46–1.93; P < 0.0001; YKL-40: OR, 1.02; 95% CI 1.01–1.03; P = 0.0001). Adding IL-6 and YKL-40 significantly increased the area under the receiver operating characteristic curves for the prediction models of Essen Stroke Risk Score (0.03, P < 0.0001) and Totaled Health Risks in Vascular Events Score (0.07, P < 0.0001), and yielded continuous net reclassification improvement (19.0%, P < 0.0001; 33.0, P < 0.0001).ConclusionsIn the patients with ischemic stroke or TIA, IL-6 and YKL-40 were independently associated with recurrent stroke and poor functional outcome, and improved risk classification of clinical risk algorithms.

Circulating Biomarkers Predict Symptomatic but Not Asymptomatic Carotid Artery Stenosis

Background: Subjects exposed to risk factors such as age, gender, hypertension, diabetes mellitus, and smoking are prone to atherosclerotic events. Aims: The main aim of this longitudinal cohort study was to determine whether the role of novel plasma biomarkers for atherosclerotic carotid artery disease is different in subjects developing symptomatic carotid artery stenosis (CAS), as opposed to those with incident asymptomatic CAS. Methods: The following biomarkers were measured in 5,550 middle-aged subjects in a population-based cohort study: C-reactive protein (CRP), lipoprotein-associated phospholipase A2 mass and activity, proneurotensin, midregional proadrenomedullin (MR-proADM), midregional proatrial natriuretic peptide (MR-proANP), N-terminal pro-B-type natriuretic peptide (NT pro-BNP), copeptin, and cystatin C. After exclusion of those with prevalent CAS, subjects were thereafter followed in national patient registers for 23.4 (interquartile range 19.5–24.3) years regarding incident symptomatic and asymptomatic CAS. Results: Among 110 patients with confirmed incident CAS, 56 were symptomatic and 54 were asymptomatic. When including conventional risk markers in a Cox regression analysis, NT pro-BNP (hazard ratio [HR] 1.59; 95% confidence interval [CI]: 1.20–2.11), MR-proADM (HR 1.40; CI: 1.13–1.73), cystatin C (HR 1.21; CI: 1.02–1.43), and CRP (HR 1.53; CI: 1.13–1.73) were independently associated with incident symptomatic CAS, whereas no plasma biomarker was associated with incident asymptomatic CAS. Conclusion: Plasma biomarkers NT pro-BNP, MR-proADM, cystatin C, and CRP were independently associated with incident symptomatic CAS, whereas no such association could be demonstrated with incident asymptomatic CAS. As these biomarkers indicate future development of clinically relevant atherosclerotic CAS, their potential utility in relation to intensified preventive measures and selection of potential candidates for carotid surgery should be further evaluated.

Prospective Comparison of Plasma Biomarker and Traditional Risk Factor Profiles for Incident Isolated Atherosclerotic Disease and Incident Isolated Abdominal Aortic Aneurysm.

Background: Traditional risk factors for atherosclerotic disease (AD) are well-known, of which some are relevant also for abdominal aortic aneurysms (AAA). The present study compares the importance of plasma biomarkers and traditional risk factor profiles for incident AD without concomitant AAA (isolated AD) and AAA without concomitant AD (isolated AAA) during long-term follow-up.Methods: In the Malmö Diet and Cancer Study—cardiovascular cohort, 5,381 participants were free from atrial fibrillation or flutter, AD (coronary artery disease, atherothrombotic ischemic stroke, carotid artery disease, or peripheral artery disease), and AAA underwent blood sampling under standardized fasting conditions between 1991 and 1994. Cox proportional hazards regression analysis was used to calculate hazard ratios (HR) with 95% CIs.Results: During a median follow-up of 23.1 years, 1,152 participants developed isolated AD, and 44 developed isolated AAA. Adjusted HR for lipoprotein-associated phospholipase A2 (mass) (HR 1.53, 95% CI 1.14–2.04 vs. HR 1.05, 95% CI.99–1.12) was higher for incident isolated AAA compared to incident isolated AD, respectively. Mid-regional pro-adrenomedullin (MR-proADM) was associated with incident isolated AD (HR 1.17, 95% CI 1.1–1.25) and incident isolated AAA (HR 1.47, 95% CI 1.15–1.88). MR-proADM was correlated (r = 0.32; p < 0.001) to body mass index (BMI), and BMI was associated with increased risk of incident isolated AAA (HR 1.43, 95% CI 1.02–2). No participant with diabetes mellitus (DM) at baseline developed isolated AAA (0/44), whereas DM was associated with an increased risk of isolated AD (HR 2.57, 95% CI 2.08–3.18). Adjusted HR for male sex (HR 4.8, 95% CI 2.42–9.48, vs. HR 1.76, 95% CI 1.56–1.98) and current smoking (HR 4.79, 95% CI 2.42–9.47 vs. HR 1.97, 95% CI 1.73–2.23) were higher in the incident isolated AAA group compared to the incident isolated AD group, respectively.Conclusions: The data supports the view that components of vascular inflammation and cardiovascular stress drives AAA development, whereas glycated cross-links in abdominal aortic wall tissue may have a plausible role in reducing AAA risk in individuals with DM.

Quantile-Specific Heritability of Inflammatory and Oxidative Stress Biomarkers Linked to Cardiovascular Disease.

PurposeHeritability (h2, the proportion of the phenotypic variance attributable to additive genetic effects) is traditionally assumed to be constant throughout the distribution of the phenotype. However, the heritabilities of circulating C-reactive protein, interleukin-6, plasminogen activator inhibitor type-1 (PAI-1), and monocyte chemoattractant protein-1 (MCP-1) concentrations depend upon whether the phenotype is high or low relative to their distributions (quantile-dependent expressivity), which may account for apparent gene–environment interactions. Whether the heritabilities of other inflammatory biomarkers linked to cardiovascular disease are quantile-dependent remain to be determined.Patients and MethodsQuantile-specific offspring-parent (βOP) and full-sib regression slopes (βFS) were estimated by applying quantile regression to the age- and sex-adjusted phenotypes of families surveyed as part of the Framingham Heart Study. Quantile-specific heritabilities were calculated as: h2=2βOP/(1+rspouse) and h2={(1+8rspouseβFS)0.5–1}/(2rspouse).ResultsHeritability (h2 ± SE) of lipoprotein-associated phospholipase A2 (Lp-PLA2) mass concentrations increased from 0.11 ± 0.03 at the 10th percentile, 0.08 ± 0.03 at the 25th, 0.12 ± 0.03 at the 50th, 0.20 ± 0.04 at the 75th, and 0.26 ± 0.06 at the 90th percentile, or 0.0023 ± 0.0006 per each one-percent increase in the phenotype distribution (Plinear trend= 0.0004). Similarly, h2 increased 0.0029 ± 0.0011 (Plinear trend= 0.01) for sP-selectin, 0.0032 ± 0.0009 (Plinear trend= 0.0001) for soluble intercellular adhesion molecule 1 (sICAM-1), and 0.0026 ± 0.0006 for tumor necrosis factor receptor 2 (TNFR2) (Plinear trend= 5.0 × 10−6) per each one-percent increase in their distributions when estimated from βOP. Osteoprotegerin and soluble ST2 heritability also increased significantly with increasing percentiles of their distributions when estimated from βFS. Lp-PLA2 activity, CD40 ligand, TNFα, interleukin-18, and myeloperoxidase heritability showed no significant quantile-dependence.ConclusionThe heritabilities of circulating Lp-PLA2-mass, sP-selectin, sICAM-1, TNFR2, osteoprotegerin and soluble ST2 concentrations are quantile-dependent, which may contribute to purported genetic modulations of: 1) sP-selectin’s relationships to venous thrombosis, pulmonary hypertension, type 2 diabetes and atorvastatin treatment; 2) sICAM-I’s relationships to brain abscess and atorvastatin treatment; and 3) Lp-PLA2’s relationships to myocardial infarction and preeclampsia.

Comparison of Lp-PLA2 Activity, Lp-PLA2 Mass and Lp-PLA2 mRNA in Acute Coronary Syndrome Patients

Background: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a risk predictor for cardiovascular diseases (CVD). Generally, plasma Lp-PLA2 was thought to be secreted by circulatory inflammatory cells. Lp-PLA2 mRNA expression of PBMC may also be a risk predictor. Methods: A total of 104 subjects angiographically verified ACS patients were enrolled, including 73 unstable angina pectoris (UAP) patients and 31 acute myocardial infarction (AMI) patients. Plasma lipids, Lp-PLA2 activity and Lp-PLA2 mass were measured. Lp-PLA2 mRNA expression of PBMC was relatively quantified by real-time fluorescence PCR. Results: Plasma Lp-PLA2 activity was increased in AMI patients compared to UAP patients (395.21±145.91 vs. 328.53±127.03 U/L, p=0.024). Lp-PLA2 mass of AMI patients was also higher than UAP patients (136.43±45.46 vs. 119.16±44.19 ng/mL, p=0.093), while PBMC mRNA expression was not statistically different [1.07 (0.74, 1.57) vs. 0.88(0.49, 1.99), p=0.453]. Comparing Lp-PLA2 mRNA by groups, Lp-PLA2 mRNA level was higher in male ACS patients and smoking ACS patients (p=0.008, p=0.048, respectively). Multivariate logistic regression analysis showed that Lp-PLA2 activity was an AMI risk predictor (OR=5.224, 95% CI 1.687-16.181, p=0.004), after smoking, systolic blood pressure, diabetes and hyperlipidemia were adjusted. Recurrent ACS patients were older (p=0.035), but they showed lower levels of Lp-PLA2 mass and Lp-PLA2 activity (p=0.014, p=0.045, respectively), compared to primary ACS patients. Conclusion: Smoking may be an important regulatory factor for Lp-PLA2 mRNA expression in PBMC. Among three Lp-PLA2 indexes, Lp-PLA2 activity was the best marker indicating AMI risk, while Lp-PLA2 mass maybe play better role as a predictor in avoiding ACS recurrence.

Relationship between Lp-PLA2 and in-stent restenosis after coronary stenting: a 3-year follow-up study.

Coronary in-stent restenosis (ISR) is an important complication of percutaneous coronary intervention (PCI). However, the relationship between lipoprotein associated phospholipase A2 (Lp-PLA2) level and ISR after PCI is rarely reported. This study aims to explore the relationship between Lp-PLA2 and the occurrence of ISR at post-PCI and its predictive value for ISR. Plasma Lp-PLA2 mass were measured in 847 patients planting 1262 stents and evaluated along with known risk indicators. One-year angiographic follow-up showed that baseline elevated Lp-PLA2 mass was strongly associated with early restenosis (95% CI = 1.062-3.050, P < 0.05). Beyond the first year, the occurrence of late restenosis (95% CI = 1.043-3.214, P < 0.05) was significantly larger in the elevated Lp-PLA2 group. Kaplan-Meier analysis after three-year clinical follow up suggested that Lp-PLA2 mass did add the positive effect on the occurrence of major adverse cardiovascular events (MACEs). In conclusion, increased baseline plasma Lp-PLA2 predicts increased risks of re-stenosis and MACEs, which may be a novel biomarker for predicting ISR and MACEs.

The effect of hepatitis C virologic clearance on cardiovascular disease biomarker lipoprotein-associated phospholipase A2 and its relation to serum lipids

BackgroundChronic hepatitis C virus (HCV) infection has been linked to cardiovascular disease (CVD). However, CVD risk prediction in chronic HCV-infected patients is problematic as the prevalence of different cardiac biomarkers in these patients is currently unknown. Serum lipids, which are routinely used in traditional CVD risk scores, may underestimate CVD risk in these patients, while non-hepatically produced biomarkers, including lipoprotein-associated phospholipase A2 (Lp-PLA2), may better reflect CVD risk. In this study, we aimed to evaluate the effect of sustained virologic response (SVR) on CVD risk, predicted by Lp-PLA2 mass in comparison with serum lipid levels.ResultsNinety chronic HCV-infected patients were enrolled in this study. Serum Lp-PLA2 mass was measured before and after HCV treatment via direct-acting antivirals and compared with the changes in serum lipids and Framingham risk score (FRS). The Lp-PLA2 level was categorized into high (>235 ng/ml) or low predicted CVD risk (≤235 ng/ml). Mean Lp-PLA2 mass significantly decreased from 322.37 ± 79.15 ng/ml to 263.79 ± 51.804 ng/ml with SVR, and the number of high-risk patients significantly dropped from 82.22 to 60% after treatment. Total cholesterol, low-density lipoprotein, and high-density lipoprotein levels were low/optimal at baseline (170 ± 40.34 mg/dl, 71.98 ± 24.12 mg/dl, and 48.43 ± 6.79 mg/dl) and significantly increased with SVR (195.66 ± 55.68 mg/dl, 103.24 ± 46.57 mg/dl, and 53.91 ± 8.67 mg/dl). According to FRS, only 30% of patients were moderate/high risk at baseline and insignificantly declined to 28.89% post-treatment.ConclusionLp-PLA2 may be a better predictor of CVD risk in chronic HCV-infected patients. Furthermore, SVR may reduce hepatic inflammation and consequently CVD risk.

Statins Therapy Improves Acute Ischemic Stroke in Patients with Cardio-metabolic Disorders Measured by Lipoprotein-Associated Phospholipase A2 (Lp-PLA2): New Focal Point.

Acute ischemic stroke (AIS) leads to neuronal and endothelial damage that activate the release of proinflammatory mediators such as lipoprotein-associated phospholipase A2 (Lp-PLA2), which lead to the development of brain edema injury. Most of statins produce differential effects on Lp-PLA2 activity and mass with a comparable reduction in low-density lipoprotein (LDL) serum levels. The aim of this study is to evaluate the differential effect of different statins on the mass of level of Lp-PLA2 in patients with AIS. A total of 69 patients with AIS aged 40-70 years compared with matched 39 healthy controls were involved in this case-control study. The AIS patients were divided according to the statins therapy into 39 patients on statins therapy (statins on), and 30 patients were not on the statins therapy (statins off). Anthropometric variables including weight, height, body mass index (BMI), and blood pressure profile were estimated. Besides, biochemical variables including lipid profile[total cholesterol (TC), triglyceride (TG), LDL, very low-density lipoprotein (VLDL), high-density lipoprotein (HDL)], Lp-PLA2 mass levels, high-sensitive C-reactive protein (Hs-CRP) were estimated. Patients with AIS had high Lp-PLA2 mass levels (P < 0.01) that positively correlated with high Hs-CRP, blood pressure, BMI, TC, TG, VLDL, LDL, and negatively correlated with HDL as compared with healthy controls. As well, statins on patients had lower Lp-PLA2 mass levels (9.82 ± 3.19 IU/mL) compared with statins off patients (16.55 ± 4.72 IU/mL), (P = 0.0001). Regarding the gender differences in the Lp-PLA2 mass level, it was higher in men patients with AIS compared with comparable females (P = 0.03). Lp-PLA2 mass level was higher in patients with AIS and linked with underlying poor cardio-metabolic disorders. Therefore, the Lp-PLA2 mass level is observed to be a surrogate biomarker of AIS mainly in patients with poor cardio-metabolic disorders. Statin therapy improves the Lp-PLA2 mass level and the poor cardio-metabolic profile in patients with AIS.

Effects of canola or olive oil on plasma lipids, lipoprotein-associated phospholipase A2 and inflammatory cytokines in patients referred for coronary angiography

BackgroundThe potential cardioprotective benefits of olive oil (OO) and canola oil (CO) consumption have been shown in some studies. The present study compared the effects of CO and OO on plasma lipids, some inflammatory cytokines, and lipoprotein-associated phospholipase A2 (Lp-PLA2) mass and activity in patients undergoing coronary angiography.MethodsThe current randomized, controlled, parallel-arm, clinical trial involved 48 patients (44 men and 4 women, aged 57.63 ± 6.34 years) with at least one classic cardiovascular risk factor (hypertension, dyslipidemia, or diabetes) who referred for coronary angiography. Patients were randomly divided into two groups and received 25 mL/day refined olive oil (n = 24) or canola oil (n = 24) for 6 weeks. Plasma lipids, some selected inflammatory markers, and Lp-PLA2 levels were measured at baseline and after the intervention.ResultsCO consumption produced a significant reduction in plasma Lp-PLA2 mass (− 0.97 ± 1.84 vs. 0.34 ± 1.57 ng/mL, p = 0.008 for CO and OO, respectively), whereas the mean changes in interleukine-6 concentration were significantly lower after OO consumption compared with CO (− 9.46 ± 9.46 vs. -0.90 ± 6.80 pg/mL, p = 0.008 for OO and CO, respectively). After 6 weeks of intervention, no significant changes were observed in plasma Lp-PLA2 activity, complement C3, C4, or lipid profiles in the two intervention groups.ConclusionsComparing the two vegetable oils in subjects with cardiovascular risk factors showed that the consumption of olive oil is more effective in reducing the level of inflammatory cytokine interleukine-6, whereas canola oil was more effective in lowering Lp-PLA2 levels; however, this finding should be interpreted with caution, because Lp-PLA2 activity did not change significantly.Trial registrationIRCT20160702028742N5 at www.irct.ir (04/19/2019).

Influence of lipoprotein-associated phospholipase A2 mass on prognosis value of baseline platelet count for clinical outcomes after acute ischemic stroke

Background and aimsWe aimed to examine the association between baseline platelet count (PLT) and prognosis of acute ischemic stroke according to lipoprotein-associated phospholipase A2 (Lp-PLA2) mass. MethodsA total of 3254 patients with acute ischemic stroke were included in this analysis. The primary outcome was a combination of major disability and all-cause mortality (modified Rankin Scale score ≥3) at 3 months after stroke. Secondary outcome was major disability and all-cause mortality, respectively. ResultsThe prognosis value of PLT for primary outcome was significantly modified by Lp-PLA2 mass (pinteraction = 0.002). After multivariate adjustment, elevated PLT was associated with the increased risk of primary outcome in patients with high Lp-PLA2 mass (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.09–2.48; ptrend = 0.002), but not in those with low Lp-PLA2 mass (OR, 0.94; 95%CI, 0.62–1.42; ptrend = 0.181), when comparing two extreme PLT quartiles. A similar association was found between elevated PLT and major disability (pinteraction = 0.001). Elevated PLT was associated with increased risk of major disability only in patients with high Lp-PLA2 mass (OR, 1.54; 95%CI, 1.03–2.31; ptrend = 0.007), for the highest quartile vs the lowest quartile. Each 100 × 109/L increment in PLT was associated with 42% (95%CI, 12%–79%) increased risk of primary outcome and 33% (95%CI, 6%–68%) increased risk of major disability in those with high Lp-PLA2 mass. ConclusionsThe elevated PLT was associated with poor prognosis of acute ischemic stroke only in patients with high Lp-PLA2 mass. Lp-PLA2 might be an important factor influencing the prognosis value of PLT for clinical outcomes in acute ischemic stroke patients.

The Beneficial Effects of Alpha Lipoic Acid Supplementation on Lp-PLA2 Mass and Its Distribution between HDL and apoB-Containing Lipoproteins in Type 2 Diabetic Patients: A Randomized, Double-Blind, Placebo-Controlled Trial.

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a new specific vascular inflammation biomarker that is carried by the lipoproteins in the blood and plays a prominent role in the pathogenesis of atherosclerosis. Increased Lp-PLA2 levels and impaired Lp-PLA2 distribution across high-density lipoprotein (HDL) and non-HDL lipoproteins have been reported in diabetic patients, which is associated with the increase in cardiovascular disease (CVD) risk. This study is aimed at investigating the effect of alpha lipoic acid (ALA), as an antioxidant with potential cardioprotective properties, on the Lp-PLA2 mass and its distribution in diabetic patients. In a double-blind, randomized, placebo-controlled clinical trial, seventy diabetic patients were randomly allocated to ALA (1200 mg ALA as two 600 mg capsules/day) and placebo (two maltodextrin capsules/day) groups. The serum levels of total Lp-PLA2 mass, HDL-Lp-PLA2, oxidized low-density lipoproteins (ox-LDL), apolipoprotein A1 (apo A1), lipid profiles, fasting blood sugar (FBS), and insulin were measured, and apolipoprotein B- (apoB-) associated Lp-PLA2 and homeostasis model of assessment index (HOMA-IR) were calculated at the baseline and after 8 weeks of intervention. ALA significantly decreased the ox-LDL, total Lp-PLA2 mass, apoB-associated Lp-PLA2, and percent of apoB-associated Lp-PLA2 and triglyceride and increased the percent of HDL-Lp-PLA2 compared with the placebo group but had no significant effect on HDL-Lp-PLA2 mass, apo A1, lipid profiles, and glycemic indices. There was a positive correlation between the reduction in the ox-LDL level and total Lp-PLA2 mass in the ALA group. In conclusion, ALA may decrease the CVD risk by reducing the ox-LDL and Lp-PLA2 mass and improving the Lp-PLA2 distribution among lipoproteins in type 2 diabetic patients.

Effect of Increasing the Plasma Phospholipase A2 Mass on the Risk of Masked Hypertension in Humans

Background: Masked Hypertension (MHT) is associated with an increased risk for Cardiovascular Disease (CVD). The etiopathogenesis of MHT is thought to be affected by oxidative stress and vascular inflammation. This study aimed to analyze the relationships between Lipoprotein-Associated Phospholipase A2 (Lp-PLA2), a unique vascular inflammation marker, with blood pressure variation and traditional risk factors in patients with MHT, and to determine the clinical significance. Methods: One hundred eighty-three patients without any prior therapeutic medications were included and divided into the following three groups: MHT (n=82); True Hypertension (THT) [n=52]); and normotensive (n=59). An Ambulatory Blood Pressure Monitor (ABPM) was used. Clinical biochemical parameters and the Lp-PLA2 mass in each group were measured, and the related clinical characteristics and risk factors for CVD were statistically analyzed. Results: The level of Lp-PLA2 in MHT group was significantly higher than the normotensive (191.8 ± 62.58 vs.108.3 ± 44.74 ng/ml, p&lt;0.01) and true hypertension groups (191.8 ± 62.58 vs. 169.3 ± 54.55 ng/ml, p&lt;0.05). Furthermore, the incidence of MHT was correlated with the increase in Lp-PLA2, around 65% of MHT patients with a Lp-PLA2 level ≥ 225 μ mol/L. The Lp-PLA2 level had a positive correlation with ABPM measurements, office-measured systolic blood pressure, and serum Uric Acid (UA) and Low-Density Lipoprotein Cholesterol (LDL-C) levels, but a negative correlation with the High-Density Lipoprotein Cholesterol (HDL-C) level. Conclusion: An increased LP-PLA2 level was closely associated with the metabolic stress and incidence of MHT, thus exhibit an important role in the pathophysiology and diagnostic assessment of MHT.

Lipoprotein-Associated Phospholipase A2 Activity and Mass as Independent Risk Factor of Stroke: A Meta-Analysis.

Background The association between lipoprotein-associated phospholipase A2 (Lp-PLA2) and stroke risk is inconsistent. We conducted a meta-analysis to determine whether elevated Lp-PLA2 is a risk factor for stroke. Methods Studies were included if they reported Lp-PLA2 mass and/or activity levels and adjusted risk estimates of stroke. The primary outcome was overall stroke incidence. The combined results were shown as relative risks (RRs) with 95% confidence intervals (CI) for per 1 standard deviation (SD) higher value of Lp-PLA2 and the highest versus lowest Lp-PLA2 category. Results Twenty-two studies involving 157,693 participants were included for analysis. After adjusting for conventional risk factors, the RRs for overall stroke with 1 SD higher Lp-PLA2 activity and mass were 1.07 (95% CI 1.02–1.13) and 1.11 (95% CI 1.04–1.19), respectively. The RRs of ischemic stroke with 1 SD higher Lp-PLA2 activity and mass were 1.08 (95% CI 1.01–1.15) and 1.11 (95% CI 1.02–1.22), respectively. When comparing the highest and lowest levels of Lp-PLA2, the RRs of stroke for Lp-PLA2 activity and mass were 1.26 (95% CI 1.03–1.54) and 1.56 (95% CI 1.21–2.00), respectively. Finally, when comparing the highest and lowest levels of Lp-PLA2, the pooled RRs of ischemic stroke for Lp-PLA2 activity and mass were 1.29 (95% CI 1.07–1.56) and 1.68 (95% CI 1.12–2.53), respectively. Conclusions Elevated baseline Lp-PLA2 levels, detected either by activity or mass, are associated with increased stroke risk.

Lp-PLA2 activity and mass and CRP are associated with incident symptomatic peripheral arterial disease

Long follow up is needed in prospective cohort study evaluation of plasma biomarkers for incident peripheral arterial disease (PAD) Middle-aged PAD-free individuals from the cardiovascular cohort of the Malmö Diet and Cancer study (n = 5550; 1991–94) were followed prospectively for a median time of 23.4 years. The plasma biomarkers lipoprotein-associated phospholipase A2 (Lp-PLA2) activity and mass, proneurotensin, and CRP, were studied in relation to incidence of PAD until December 31st, 2016. The diagnosis of PAD could be validated and confirmed in 98%. Cox regression was used to calculate hazard ratios (HR) per 1 standard deviation increment of each respective log transformed plasma biomarker. Cumulative incidence of PAD was 4.4% (men 5.9%, women 3.3%). Adjusting for age, gender, smoking, body mass index, hypertension, diabetes mellitus, Lp-PLA2 activity (HR 1.33; 95% CI 1.17–1.52), Lp-PLA2 mass (HR 1.20; 95% CI 1.05–1.37) and CRP (HR 1.55; 95% CI 1.36–1.76) remained independently associated with incident PAD. The plasma biomarkers Lp-PLA2 activity and mass, and CRP were markers of PAD risk, implying that they might be useful biomarkers for subclinical atherosclerosis and atherosclerotic disease.

Interleukin-6 and lipoprotein-associated phospholipase A2 are associated with functional trajectories.

Background/ObjectivesInflammatory biomarkers have been associated with stroke and mortality, but inflammation may also have detrimental effects beyond acute events. We hypothesized that serum concentrations of interleukin-6 (IL6) and lipoprotein-associated phospholipase A2 (LpPLA2) were inversely associated with long-term functional decline independently of vascular risk factors, stroke and myocardial infarction (MI) occurring during follow-up.DesignProspective population based cohort studySettingThe Northern Manhattan StudyParticipants (including the sample size)Race/ethnically diverse stroke-free individuals in northern Manhattan aged ≥40 years (n = 3298).InterventionNoneMeasurementsAnnual functional assessments with the Barthel index (BI), for a median of 13 years. BI was analyzed as a continuous variable (range 0–100). Baseline demographics, risk factors, and laboratory studies were collected, including IL6 (n = 1679), LpPLA2 mass (n = 1912) and activity (n = 1937). Separate mixed models estimated standardized associations between each biomarker and baseline functional status and change over time, adjusting for demographics, vascular risk factors, social variables, cognition, and depression measured at baseline, and stroke and MI occurring during follow-up.ResultsMean age was 69 (SD 10) years, 35% were male, 53% Hispanic, 74% hypertensive, and 16–24% diabetic. LogIL6 was associated with decline in BI over time (-0.13 points per year, 95% CI -0.24, -0.02) and marginally with baseline BI (-0.20, 95% CI -0.40, 0.01). LpPLA2 activity levels were associated with baseline BI (-0.36, 95% CI -0.68, -0.04) but not change over time, and LpPLA2 mass levels were not associated with either.ConclusionIn this large population-based study, higher serum inflammatory biomarker levels were associated with disability, even when adjusting for baseline covariates and stroke and MI occurring during follow-up.

Short-term exposure to ambient air pollution and circulating biomarkers of endothelial cell activation: The Framingham Heart Study

BackgroundShort-term exposure to air pollution has been associated with cardiovascular events, potentially by promoting endothelial cell activation and inflammation. A few large-scale studies have examined the associations and have had mixed results. MethodsWe included 3820 non-current smoking participants (mean age 56 years, 54% women) from the Framingham Offspring cohort examinations 7 (1998–2001) and 8 (2005–2008), and Third Generation cohort examination 1 (2002–2005), who lived within 50 km of a central monitoring station. We calculated the 1- to 7-day moving averages of fine particulate matter (PM2.5), black carbon (BC), sulfate (SO42-), nitrogen oxides (NOx), and ozone before examination visits. We used linear mixed effect models for P-selectin, monocyte chemoattractant protein 1 (MCP-1), intercellular adhesion molecule 1, lipoprotein-associated phospholipase A2 activity and mass, and osteoprotegerin that were measured up to twice, and linear regression models for CD40 ligand and interleukin-18 that were measured once, adjusting for demographics, life style and clinical factors, socioeconomic position, time, and meteorology. ResultsWe found negative associations of PM2.5 and BC with P-selectin, of ozone with MCP-1, and of SO42- and NOx with osteoprotegerin. At the 5-day moving average, a 5 µg/m3 higher PM2.5 was associated with 1.6% (95% CI: − 2.8, − 0.3) lower levels of P-selectin; a 10 ppb higher ozone was associated with 1.7% (95% CI: − 3.2, − 0.1) lower levels of MCP-1; and a 20 ppb higher NOx was associated with 2.0% (95% CI: − 3.6, − 0.4) lower levels of osteoprotegerin. ConclusionsWe did not find evidence of positive associations between short-term air pollution exposure and endothelial cell activation. On the contrary, short-term exposure to higher levels of ambient pollutants were associated with lower levels of P-selectin, MCP-1, and osteoprotegerin in the Framingham Heart Study.