Lipoprotein-associated phospholipase A(2) and risk of coronary disease, stroke, and mortality: collaborative analysis of 32 prospective studies

Apolipoprotein B-containing lipoproteins in atherogenesis

Apolipoprotein B (apoB) is the main structural protein of LDLs, triglyceride-rich lipoproteins and lipoprotein(a), and is crucial for their formation, metabolism and atherogenic properties. In this Review, we present insights into the role of apoB-containing lipoproteins in atherogenesis, with an emphasis on the mechanisms leading to plaque initiation and growth. LDL, the most abundant cholesterol-rich lipoprotein in plasma, is causally linked to atherosclerosis. LDL enters the artery wall by transcytosis and, in vulnerable regions, is retained in the subendothelial space by binding to proteoglycans via specific sites on apoB. A maladaptive response ensues. This response involves modification of LDL particles, which promotes LDL retention and the release of bioactive lipid products that trigger inflammatory responses in vascular cells, as well as adaptive immune responses. Resident and recruited macrophages take up modified LDL, leading to foam cell formation and ultimately cell death due to inadequate cellular lipid handling. Accumulation of dead cells and cholesterol crystallization are hallmarks of the necrotic core of atherosclerotic plaques. Other apoB-containing lipoproteins, although less abundant, have substantially greater atherogenicity per particle than LDL. These lipoproteins probably contribute to atherogenesis in a similar way to LDL but might also induce additional pathogenic mechanisms. Several targets for intervention to reduce the rate of atherosclerotic lesion initiation and progression have now been identified, including lowering plasma lipoprotein levels and modulating the maladaptive responses in the artery wall.

Exploring the pathways linking fasting insulin to coronary artery disease: a proteome-wide Mendelian randomization study

BACKGROUND

Insulin is known to be associated with a higher risk of coronary artery disease (CAD), but molecular mechanisms remain unclear. This study aimed to explore protein-mediated pathways linking fasting insulin to CAD using Mendelian randomization (MR).

METHODS

This MR study examined the association between fasting insulin and CAD using genome-wide association study (GWAS) data from MAGIC and CARDIoGRAMplusC4D. To investigate underlying mechanisms, a two-step proteome-wide MR analysis was conducted. First, associations of fasting insulin with 2940 circulating proteins were assessed using GWAS of proteomics from UKB-PPP. Proteins affected by insulin were then analyzed for their association with CAD risk. Proteins selected in both steps were considered as potential mediators. Sensitivity analyses to test whether associations are robust to pleiotropy and replication using other GWAS data, including GWAS of proteomics from deCODE and GWAS of CAD from FinnGen Biobank, were performed.

RESULTS

Genetically predicted insulin was associated with a higher risk of CAD (odds ratio 1.79, 95% confidence interval 1.34 to 2.40). At a false discovery rate of 0.05, insulin affected 355 proteins, ten of which were both increased by insulin and linked to a higher risk of CAD. After sensitivity and replication analyses, PLA2G7, GZMA, LDLR, AGRP, and HHEX were identified as reliable mediators. Mediation analyses using non-pleiotropic instruments showed that PLA2G7, GZMA, LDLR, and AGRP explained 19.50%, 6.91%, 19.31%, and 29.66% of insulin's total effect on CAD, respectively.

CONCLUSIONS

This study identified five protein mediators linking insulin to CAD. These proteins could be considered as potential targets to mitigate insulin-related cardiovascular risk, providing novel insights for drug repurposing.

Interpretable machine learning leverages proteomics to improve cardiovascular disease risk prediction and biomarker identification

BACKGROUND

Cardiovascular diseases (CVDs) rank amongst the leading causes of long-term disability and mortality. Predicting CVD risk and identifying associated genes are crucial for prevention, early intervention, and drug discovery. The recent availability of UK Biobank Proteomics data enables investigation of blood proteins and their association with a variety of diseases. We sought to predict 10 year CVD risk using this data modality and known CVD risk factors.

METHODS

We focused on the UK Biobank participants that were included in the UK Biobank Pharma Proteomics Project. After applying exclusions, 50,057 participants were included, aged 40-69 years at recruitment. We employed the Explainable Boosting Machine (EBM), an interpretable machine learning model, to predict the 10 year risk of primary coronary artery disease, ischemic stroke or myocardial infarction. The model had access to 2978 features (2923 proteins and 55 risk factors). Model performance was evaluated using 10-fold cross-validation.

RESULTS

The EBM model using proteomics outperforms equation-based risk scores such as PREVENT, with a receiver operating characteristic curve (AUROC) of 0.767 and an area under the precision-recall curve (AUPRC) of 0.241; adding clinical features improves these figures to 0.785 and 0.284, respectively. Our models demonstrate consistent performance across sexes and ethnicities and provide insights into individualized disease risk predictions and underlying disease biology.

CONCLUSIONS

In conclusion, we present a more accurate and explanatory framework for proteomics data analysis, supporting future approaches that prioritize individualized disease risk prediction, and identification of target genes for drug development.

Modifications on lipid profile and high-density lipoprotein function related to treatment with tofacitinib in female patients with rheumatoid arthritis: Impact of previous therapy with biological agents

BACKGROUND AND AIMS

Tofacitinib, a Janus kinase inhibitor, has been associated with increased cardiovascular (CV) risk in rheumatoid arthritis (RA). This study evaluated tofacitinib's effects on lipid parameters and the impact of prior biological agents' therapy in RA patients.

METHODS

Thirty female RA patients starting tofacitinib were assessed at baseline and after 3 months. Clinical assessments, health assessment questionnaire (HAQ), disease activity score 28 (DAS28), inflammatory markers, lipid profile, oxidized low-density lipoprotein (LDL), activities of paraoxonase 1 (PON 1), lipoprotein-associated phospholipase A2 (Lp-PLA2), cholesteryl ester transfer protein (CETP), high-density lipoprotein (HDL) composition, and HDL functions (cholesterol efflux and free cholesterol uptake from triglyceride-rich lipoproteins [TGRL]) upon lipolysis were measured.

RESULTS

After 3 months, HAQ and DAS28 scores improved significantly. Total cholesterol (TC), HDL-C, non-HDL-C, and HDL capacity to acquire free cholesterol from TGRL increased, while enzyme activities and cholesterol efflux capacity remained unchanged. At baseline, patients with prior biological therapy (n = 19) had lower triglycerides, TC, non-HDL-C, and apolipoprotein (apo) B compared to biologic-naïve patients (n = 11). This group exhibited no lipid changes after tofacitinib, whereas biologic-naïve patients showed atherogenic increases in TC, LDL-C, non-HDL-C, apo B, Lp-PLA2, and CETP, alongside beneficial increases in PON 1 activity.

CONCLUSION

Tofacitinib improved disease activity and functional status in RA patients with minimal lipid changes. Patients previously treated with biological agents experienced no significant lipid alterations, while biologic-naïve patients showed atherogenic lipid changes and increased PON 1 activity. Prior biologic therapy may confer a more favorable CV profile before and after tofacitinib treatment.

[Lipoprotein-associated phospholipase A2 (Lp-PLA2): Relevant biomarker and therapeutic target?]

Over the last fifteen years, numerous studies have sought to decipher the role of lipoprotein-associated phospholipase A2 (Lp-PLA2) in vascular inflammation-related diseases, notably atherosclerosis. Despite the disappointing results of clinical trials using the Lp-PLA2 inhibitor darapladib, new pathophysiological, epidemiological and genetic data have enabled the development of new inhibitors. Recent studies also show that Lp-PLA2 is involved in vascular inflammation-related diseases other than atherosclerosis (ischemic stroke, Alzheimer's disease and vascular dementia, diabetes, cancers…), and inhibition of Lp-PLA2 could have beneficial therapeutic in these diseases. This review aims to present new data on Lp-PLA2 and to evaluate its current interest as a biomarker but also as a therapeutic target.

Effect of Fibrates on Lipoprotein-associated Phospholipase A2 Mass and Activity: A Systematic Review and Meta-analysis of Controlled Clinical Trials

BACKGROUND

In vascular tissue, macrophages and inflammatory cells produce the enzyme lipoprotein- associated phospholipase A2 (Lp-PLA2). Treatment with fibrates decreases Lp-PLA2 levels in individuals with obesity and metabolic syndrome; however, these findings have not been fully clarified.

OBJECTIVE

The goal of this study was to investigate the possible effects of fibrate therapy on Lp-PLA2 mass and activity through a meta-analysis of clinical trials.

METHODS

Web of Science, PubMed, Scopus, Google Scholar, and ClinicalTrials.gov databases were searched using MeSH terms and keywords. Randomized controlled trials (RCT) evaluating the effect of statins on Lp- PLA2 mass and/or activity were included in the meta-analysis. Quantitative data were analyzed using a random- effects model and the generic inverse variance method.

RESULTS

The meta-analysis of 10 clinical trials indicated that fibrate treatment has no significant effect on Lp- PLA2 mass (fibrate vs. placebo/nothing = WMD: -3.29 ng/ml, 95% CI: -21.35, 14.78, p = 0.72; fibrate vs. active control = WMD: -1.08 ng/ml, 95% CI: -51.38, 49.22, p = 0.97); Lp-PLA2 activity (fibrate vs. active control = WMD: 0.84 nmol/ml/min, 95% CI: -0.17, 1.84, p = 0.10); HDL-LpPLA2 activity (fibrate vs. active control = WMD: 0.77 nmol/ml/min, 95% CI: -0.33, 1.88, p = 0.17); and secretory PLA2 (fibrate vs. active control = WMD: 0.37 ng/ml, 95% CI: -1.22, 1.97, p = 0.65). Also, the results of the sensitivity analysis were robust for all these parameters.

CONCLUSION

In conclusion, fibrate therapy did not reduce the mass and activity of Lp-PLA2.

Lc-ms-based untargeted metabolomics reveals potential mechanisms of histologic chronic inflammation promoting prostate hyperplasia

BACKGROUND

Chronic prostatitis may be a risk factor for developing proliferative changes in the prostate, although the underlying mechanisms are not entirely comprehended.

MATERIALS AND METHODS

Fifty individual prostate tissues were examined in this study, consisting of 25 patients diagnosed with prostatic hyperplasia combined with histologic chronic inflammation and 25 patients diagnosed with prostatic hyperplasia alone. We employed UPLC-Q-TOF-MS-based untargeted metabolomics using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry to identify differential metabolites that can reveal the mechanisms that underlie the promotion of prostate hyperplasia by histologic chronic inflammation. Selected differential endogenous metabolites were analyzed using bioinformatics and subjected to metabolic pathway studies.

RESULTS

Nineteen differential metabolites, consisting of nine up-regulated and ten down-regulated, were identified between the two groups of patients. These groups included individuals with combined histologic chronic inflammation and those with prostatic hyperplasia alone. Glycerolipids, glycerophospholipids, and sphingolipids were primarily the components present. Metabolic pathway enrichment was conducted on the identified differentially expressed metabolites. Topological pathway analysis revealed the differential metabolites' predominant involvement in sphingolipid, ether lipid, and glycerophospholipid metabolism. The metabolites involved in sphingolipid metabolism were Sphingosine, Cer (d18:1/24:1), and Phytosphingosine. The metabolites involved in ether lipid metabolism were Glycerophosphocholine and LysoPC (O-18:0/0:0). The metabolites involved in glycerophospholipid metabolism were LysoPC (P-18:0/0:0) and Glycerophosphocholine. with Impact > 0. 1 and FDR < 0. 05, the most important metabolic pathway was sphingolipid metabolism.

CONCLUSIONS

In conclusion, our findings suggest that patients with prostate hyperplasia and combined histologic chronic inflammation possess distinctive metabolic profiles. These differential metabolites appear to play a significant role in the pathogenesis of histologic chronic inflammation-induced prostate hyperplasia, primarily through the regulation of sphingolipids and glycerophospholipids metabolic pathways. The mechanism by which histologic chronic inflammation promotes prostate hyperplasia was elucidated through the analysis of small molecule metabolites. These findings support the notion that chronic prostatitis may contribute to an increased risk of prostate hyperplasia.

A stepwise integrated strategy to explore quality markers of Qishen Yiqi dripping pills against myocardial ischemia

BACKGROUND

Numerous experiments and clinical practices have demonstrated the effectiveness of Qishen Yiqi dripping pills (QSYQ) on myocardial ischemia (MI). However, the bioactive ingredients and mechanisms remain unclear, leading to huge gaps between quality control and biological effect of QSYQ. Discovering quality markers (Q-markers) based on effective components is crucial for ensuring stable quality and clinical effectiveness of QSYQ.

PURPOSE

To explore Q-markers of QSYQ against MI by a stepwise strategy integrating serum pharmacochemistry, network pharmacology, metabolomics, quantitative analysis, and cell experiments.

METHODS

Firstly, liquid/gas chromatography-mass spectrometry was applied to characterize chemical profiles of QSYQ in vitro and in vivo. Based on the serum migrating constituents, a component-target-MI interaction network was constructed. Subsequently, pharmacodynamics and metabolomics were conducted to evaluate cardioprotective effect and potential mechanism of QSYQ. Next, conjoint analysis of network pharmacology and metabolomics was performed to screen candidate Q-markers. Finally, the measurability and bioactivity were validated to justify their usage as Q-markers.

RESULTS

A total of 97 components were identified in QSYQ, 24 prototypes of which were detected in serum. The "component-target-disease" interaction network was constructed based on serum migrating constituents. Pharmacodynamic results showed that QSYQ effectively improved cardiac function, attenuated inflammatory cell infiltration, alleviated myocardial fibrosis, and reduced the levels of myocardial enzymes and oxidative stress in MI rats. Metabolomics study demonstrated that 59 metabolites were markedly altered in MI rats, 25 of which were significantly reversely regulated by QSYQ. After integrative analysis of network pharmacology and metabolomics, 12 components were selected as candidate Q-markers of QSYQ, and the contents were quantified. These candidate Q-markers displayed synergistic protective effects against H2O2-induced injury in H9c2 cells. Taken together, 12 components with properties of transitivity and traceability, effectiveness, measurability, and compatibility contribution were defined as representative Q-markers of QSYQ, including Astragaloside IV, Ononin, Calycosin, Formononetin, Rosmarinic acid, Cryptotanshinone, Salvianolic acid A, Tanshinol, Ginsenoside Rb1, Ginsenoside Rg1, Nerolidol, and Santalol.

CONCLUSION

In this study, a novel stepwise integrated strategy was presented for discovering Q-markers related to therapeutic effects of traditional Chinese medicine prescriptions. Twelve comprehensive and representative Q-markers of QSYQ were identified for the first time to improve its quality control.

Targeting Inflammatory Pathways in Atherosclerosis: Exploring New Opportunities for Treatment

PURPOSE OF THE REVIEW

This review discusses the molecular mechanisms involved in the immuno-pathogenesis of atherosclerosis, the pleiotropic anti-inflammatory effects of approved cardiovascular therapies and the available evidence on immunomodulatory therapies for atherosclerotic cardiovascular disease (ACVD). We highlight the importance of clinical and translational research in identifying molecular mechanisms and discovering new therapeutic targets.

RECENT FINDINGS

The CANTOS (Canakinumab Anti-Inflammatory Thrombosis Outcomes Study) trial was the first to demonstrate a reduction in cardiovascular (CV) risk with anti-inflammatory therapy, irrespective of serum lipid levels. ACVD is the leading cause of death worldwide. Although targeting principal risk factors significantly reduces CV risk, residual risk remains unaddressed. The immunological mechanisms underlying atherosclerosis represent attractive therapeutic targets. Several commonly used and non-primarily anti-inflammatory drugs (i.e. SGLT2i, and PCSK9i) exhibit pleiotropic properties. Otherwise, recent trials have investigated the blockade of primarily inflammatory compounds, trying to lower the residual risk via low-dose IL-2, PTPN22 and CD31 pathway modulation. In the era of precision medicine, modern approaches may explore new pharmacological targets, identify new markers of vascular inflammation, and evaluate therapeutic responses.

Association of Lipoprotein-Associated Phospholipase A2 and Lipoprotein(a) With the Risk of Recurrence Stroke in Patients With Acute Ischemic Stroke

OBJECTIVE

It is still a major global challenge to reduce the high morbidity and mortality of acute ischemic stroke (AIS) and improve the prognosis of patients. This study aims to investigate the prognostic value of lipoprotein-associated phospholipase A2 (Lp-PLA2) combined with lipoprotein(a) (Lp(a)) for long-term stroke recurrence in patients with AIS.

METHODS

This study included 580 patients with AIS. Assessment of Lp-PLA2 and Lp(a) levels was conducted upon patient admission. Continuous monitoring over the long term categorized stroke recurrence as an endpoint. Patients were categorized based on these identified thresholds to compare the risk of stroke recurrence: high Lp-PLA2 and high Lp(a), high Lp-PLA2 and low Lp(a), low Lp-PLA2 and high Lp(a), and low Lp-PLA2 combined with low Lp(a).

RESULTS

Among the 580 participants, 101 individuals (17.41%) experienced stroke recurrence within the 2-year follow-up. The majority were male (61.39%), with a median age of 62 years (interquartile range: 55-69.5). Factors independently associated with heightened the risk of recurrence stroke comprised age (hazard ratio [HR], 1.025; p = 0.021), diabetes mellitus (HR, 1.751; p = 0.007), Lp-PLA2 (HR, 1.004; p < 0.001), and Lp(a) (HR, 1.002; p < 0.001). Noteworthy is that the combination of Lp-PLA2 and Lp(a) displayed superior predictive efficacy for long-term stroke recurrence risk in AIS patients compared to individual factors.

CONCLUSION

This investigation underscores the potential advantage of leveraging the combined impact of Lp-PLA2 in conjunction with Lp(a) as a more precise and cost-effective predictive tool for the risk of recurrence stroke in patients with AIS.

Association of plasma neurofilament light chain and Lipoprotein-related phospholipase A2 with motor subtypes of Parkinson's disease

Neurofilament light chain (NfL) levels were reliable biomarkers of neurodegeneration in Parkinson's disease (PD). Lipoprotein-related Phospholipase A2(Lp-PLA2) levels have also been increasingly studied in PD. We aimed to explore the association of plasma NfL and Lp-PLA2 with the diagnosis, motor subtypes and disease severity of PD. Plasma NfL and Lp-PLA2 were assayed separately in 106 participants (74 PD and 32 healthy controls, HC). The motor subtypes of PD were classified according to the MDS-UPDRS components, and motor and non-motor manifestations of patients were also evaluated. Subsequently, correlation analyses were performed. The plasma NfL levels were higher in the PD than HC, and were positively correlated with age, UPDRS II, UPDRS III and the modified Hoehn and Yahr staging scale (H&Y stage) in the PD. Moreover, plasma Lp-PLA2 levels were lower in the PD than HC, and were positively correlated with Parkinson's Disease Quality of Life Questionnaire (PDQ-39) in the PD. For further distinguishing tremor-dominant (TD) from postural instability and gait difficulty-dominant (PIGD), plasma Lp-PLA2 levels were higher in the TD than PIGD, but there was no significant difference in NfL. plasma Lp-PLA2 levels were positively correlated with UPDRS I, Hamilton Anxiety Rating Scale (HAMA) and PDQ-39 in the TD. These resultssuggest that NfL and Lp-PLA2 may be potential biomarkers for the diagnosis of PD. We first demonstrated the potential utility of plasma Lp-PLA2 in differentiating motor subtypes. These findings deserve further evidence in larger PD cohorts.

Effect of Statin Treatment on Lipoprotein-Associated Phospholipase A2 Mass and Activity: A Systematic Review and Meta-analysis of Randomized Placebo-Controlled Trials

PURPOSE

The goal of this meta-analysis was to establish whether statin treatment reduces Lp-PLA2 mass concentration and/or activity.

METHODS

PubMed, Scopus, Web of Science, ClinicalTrials.gov, and Google Scholar databases were searched using MESH terms and keywords. Randomized controlled trials (RCT) with either parallel or cross-over design examining the effect of statins on Lp-PLA2 mass and/or activity were included in meta-analysis.

RESULTS

Out of 256 articles, 10 RCT were selected for meta-analysis. Statin therapy significantly reduced both Lp-PLA2 mass (WMD -44.46 ng/mL; 95%CI -59.01, -29.90; p < 0.001; I2 = 93%) and activity (WMD -39.37 nmol/min/mL; 95%CI -69.99, -8.75; p = 0.01; I2 = 100%). The sensitivity analysis was robust for Lp-PLA2 mass and was also positive for two studies concerning Lp-PLA2 activity.

CONCLUSION

Statin therapy significantly reduced both Lp-PLA2 mass and activity.

Emerging Circulating Biomarkers for Enhanced Cardiovascular Risk Prediction

Cardiovascular disease (CVD) continues to be the primary cause of mortality worldwide, underscoring the importance of identifying additional cardiovascular risk factors. The consensus is that lipid levels alone do not fully reflect the status of atherosclerosis, thus necessitating extensive research on cardiovascular biomarkers. This review encompasses a wide spectrum of methodologies for identifying novel risk factors or biomarkers for CVD. Inflammation, oxidative stress, plaque instability, cardiac remodeling, and fibrosis play pivotal roles in CVD pathogenesis. We introduce and discuss several promising biomarkers-namely, osteocalcin, angiogenin, lipoprotein-associated phospholipase A2, growth differentiation factor 15, galectin-3, growth stimulation expressed gene 2, and microRNAs, all of which have potential implications in the assessment and management of cardiovascular risk.

The joint association of lipoprotein(a) and lipoprotein-associated phopholipase A2 with the risk of stroke recurrence

BACKGROUND AND PURPOSE

Currently little is known about the joint association of lipoprotein (a) [Lp(a)] and lipoprotein-associated phospholipase A2 (Lp-PLA2) with stroke recurrence.

METHODS

In this prospective multicenter cohort study, 10,675 consecutive acute ischemic stroke (IS) and transient ischemic attack (TIA) patients with Lp(a) and Lp-PLA2 were enrolled. The association of stroke recurrence within 1 year with Lp(a) and Lp-PLA2 was assessed using Cox proportional hazards models and Kaplan-Meier curves. The interaction between Lp(a) and Lp-PLA2 with stroke recurrence was evaluated by multiplicative and additive scales.

RESULTS

A significant joint association of Lp(a) and Lp-PLA2 with the risk of stroke recurrence was observed. Multivariate Cox regression analysis demonstrated that the combination of elevated Lp(a) (≥ 50 mg/dL) and Lp-PLA2 (≥175.1 ng/mL) was independently associated with the risk of stroke recurrence (adjusted hazard ratio: 1.42; 95% confidence interval [CI]: 1.15-1.76). Both significant multiplicative [(exp(β3): 1.63, 95% CI: 1.17-2.29, P = 0.004] and additive interaction (RERI: 0.55, 95% CI: 0.20-0.90, P = 0.002; AP: 0.39, 95% CI, 0.24-0.53) were observed between Lp(a) and Lp-PLA2.

CONCLUSIONS

Our results indicated that Lp(a) and Lp-PLA2 have a joint association with the risk of stroke recurrence in IS/TIA patients. Patients with concomitant presence of elevated Lp(a) and Lp-PLA2 have greater risk of stroke recurrence.

Emerging Therapeutic Targets for Acute Coronary Syndromes: Novel Advancements and Future Directions

Acute coronary syndrome (ACS) remains a major cause of morbidity and mortality worldwide, requiring ongoing efforts to identify novel therapeutic targets to improve patient outcomes. This manuscript reviews promising therapeutic targets for ACS identified through preclinical research, including novel antiplatelet agents, anti-inflammatory drugs, and agents targeting plaque stabilization. Preclinical studies have expounded these agents' efficacy and safety profiles in mitigating key pathophysiological processes underlying ACS, such as platelet activation, inflammation, and plaque instability. Furthermore, ongoing clinical trials are evaluating the efficacy and safety of these agents in ACS patients, with potential implications for optimizing ACS management. Challenges associated with translating preclinical findings into clinical practice, including patient heterogeneity and trial design considerations, are also discussed. Overall, the exploration of emerging therapeutic targets offers promising avenues for advancing ACS treatment strategies and improving patient outcomes.

Correlation between lipoprotein-associated phospholipase A2 and poststroke mild cognitive impairment

OBJECTIVES

This study aimed to investigate the correlation between serum lipoprotein-associated phospholipase A2 (Lp-PLA2) and poststroke mild cognitive impairment (PSMCI).

METHODS

The patients included in the study were divided into PSMCI (68 cases) and cognitively normal (CN) (218 cases) groups and followed up for six months. Demographic and clinical data were collected. A logistic regression analysis was performed to determine whether Lp-PLA2 is an independent risk factor for PSMCI. Spearman's correlation analysis was used to examine the correlation between Lp-PLA2 levels and Montreal Cognitive Assessment (MoCA) scores. A receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic threshold value of Lp-PLA2 for PSMCI.

RESULTS

Serum Lp-PLA2 levels were significantly higher in the PSMCI group than in the CN group. The logistic regression analysis showed that Lp-PLA2 was an independent risk factor for PSMCI (OR = 1.05, 95% CI = 1.03-1.07). Spearman's correlation analysis revealed a significant correlation between the Lp-PLA2 levels and MoCA scores (R = -0.49). The area under the ROC curve for Lp-PLA2 was 0.849, and the threshold value for PSMCI occurrence was 236.8 ng/ml.

CONCLUSIONS

Elevated serum Lp-PLA2 is an independent risk factor for PSMCI and may serve as a potential biomarker for PSMCI.

Programmed death of macrophages in atherosclerosis: mechanisms and therapeutic targets

Atherosclerosis is a progressive inflammatory disorder of the arterial vessel wall characterized by substantial infiltration of macrophages, which exert both favourable and detrimental functions. Early in atherogenesis, macrophages can clear cytotoxic lipoproteins and dead cells, preventing cytotoxicity. Efferocytosis - the efficient clearance of dead cells by macrophages - is crucial for preventing secondary necrosis and stimulating the release of anti-inflammatory cytokines. In addition, macrophages can promote tissue repair and proliferation of vascular smooth muscle cells, thereby increasing plaque stability. However, advanced atherosclerotic plaques contain large numbers of pro-inflammatory macrophages that secrete matrix-degrading enzymes, induce death in surrounding cells and contribute to plaque destabilization and rupture. Importantly, macrophages in the plaque can undergo apoptosis and several forms of regulated necrosis, including necroptosis, pyroptosis and ferroptosis. Regulated necrosis has an important role in the formation and expansion of the necrotic core during plaque progression, and several triggers for necrosis are present within atherosclerotic plaques. This Review focuses on the various forms of programmed macrophage death in atherosclerosis and the pharmacological interventions that target them as a potential means of stabilizing vulnerable plaques and improving the efficacy of currently available anti-atherosclerotic therapies.

Association of Lipoprotein-associated phospholipase A2 With Carotid Intima-Media Thickness in Acute Cerebral Infarction Patients

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an inflammatory marker associated with atherosclerotic and cardiovascular diseases. This study aimed to explore the association of Lp-PLA2 with carotid intima-media thickness (cIMT) in patients with acute ischemic stroke (AIS) and explore a threshold level to predict the risk of vulnerable plaques. This retrospective observational study included patients with AIS in the Neurology Department of our Hospital between January 2018 and December 2019. The study included 293 patients aged 65.29 ± 12.11 years, including 212 males, of whom 124 had carotid intima-media thickening (42.32%). Multivariable logistic regression showed that Lp-PLA2 level was an independent risk factor for cIMT (odds ratio [OR] = 1.004, 95% confidence interval [95% CI] 1.001-1.008, P = .008). Threshold effect analysis showed that the risk of vulnerable carotid plaque occurrence increased by 2% for every 1 ng/mL increase in Lp-PLA2 level with serum Lp-PLA2 levels between 157 and 279 ng/mL; this increase was statistically significant (OR = 1.02, 95% CI 1.01-1.03, P < .001). Serum Lp-PLA2 is an independent risk factor for increased cIMT in patients with AIS, and a threshold Lp-PLA2 level between 157 and 279 ng/mL showed a higher risk of carotid plaque rupture.

Linking biomarkers with healthy lifestyle outcomes after stroke: Supplementary results of a 12-month randomized controlled trial

BACKGROUND AND AIMS

Participation in a healthy lifestyle intervention such as the Diabetes Prevention Program Group Lifestyle Balance-adapted for stroke (GLB-CVA) may reduce stroke burden. Identifying biomarkers associated with lifestyle changes may enhance an individualized approach to stroke recovery. We investigated metabolic biomarkers related to cardiovascular and neurological function in individuals with stroke in the GLB-CVA study and healthy (non-stroke) individuals.

METHODS AND RESULTS

Participants with chronic (>12 months) stroke were recruited to this wait-list randomized controlled trial if they were overweight (BMI ≥25 kg/m2). Participants were randomized to (1) the GLB-CVA program to complete 22 educational sessions addressing behavioral principals of dietary and physical activity or (2) a 6 month wait-list control (WLC). Biomarkers [Plasma irisin, vascular endothelial growth factor, lipoprotein-associated phospholipase A2 (Lp-PLA2), insulin-like growth factor 1 and brain-derived neurotrophic factor (BDNF)] were collected at baseline, 3, and 6 months. Age-matched healthy individuals were recruited for biomarker assessment. Compared to healthy adults (n = 19), participants with stroke (GLB-CVA = 24; WLC = 24) at baseline had higher tHcy levels (p < 0.001) and lower PLA2 levels (p = 0.016). No statistically significant interactions were observed for any biomarkers between the GLB-CVA and WLC or between people who achieved 5% weight loss and those who did not.

CONCLUSION

Participation in a 6-month healthy lifestyle program did not result in statistically significant changes to select metabolic biomarker levels for our participants with chronic stroke. However, participants with stroke demonstrated a unique biomarker profile compared to age-matched healthy individuals.

B. Comparison of Different Vascular Biomarkers for Predicting In-Hospital Mortality in Severe SARS-CoV-2 Infection

Severe SARS-CoV-2 elicits a hyper-inflammatory response that results in intravascular inflammation with endothelial injury, which contributes to increased mortality in COVID-19. To predict the outcome of severe SARS-CoV-2 infection, we analyzed the baseline level of different biomarkers of vascular disorders in COVID-19 subjects upon intensive care unit (ICU) admission and prior to any vaccination. A total of 70 severe COVID-19 patients (37 survivors and 33 non-survivors) were included with 16 age- and sex-matched controls. Vascular dysfunction was monitored via soluble VCAM-1, E-selectin, ACE2 and Lp-PLA2, while abnormal platelet activation was evaluated by soluble P-selectin and CD40L in parallel. These results were correlated with routine laboratory parameters and disease outcomes. Among these parameters, VCAM-1 and ACE2 showed significantly higher serum levels in COVID-19 patients with early death vs. convalescent subjects. VCAM-1 was significantly correlated with the Horowitz index (r = 0.3115) and IL-6 (r = 0.4599), while ACE2 was related to E-selectin (r = 0.4143) and CD40L (r = 0.2948). Lp-PLA2 was altered in none of these COVID-19 subcohorts and showed no relationship with the other parameters. Finally, the pre-treatment level of VCAM-1 (≥1420 ng/mL) and ACE2 activity (≥45.2 μU/mL) predicted a larger risk for mortality (Log-Rank p = 0.0031 and p = 0.0117, respectively). Vascular dysfunction with endothelial cell activation is linked to lethal COVID-19, and highly elevated soluble VCAM-1 and ACE2 at admission to ICU may predict unfavorable outcomes.

Lipoprotein-associated phospholipase A2 predicts cardiovascular death in patients on maintenance hemodialysis: a 7-year prospective cohort study

BACKGROUND

Cardiovascular diseases (CVD) is the leading cause of death among maintenance hemodialysis patients, with dyslipidemia being a prevalent complication. The paradoxical relationship between cardiovascular outcomes and established lipid risk markers, such as low-density lipoprotein cholesterol (LDL-C), complicates lipid management in this population. This study investigated Lipoprotein-associated phospholipase A2 (Lp-PLA2), an emerging biomarker known for its proinflammatory and proatherogenic properties, as a potential cardiovascular prognostic marker in this cohort. In this context, the association between Lp-PLA2 levels and cardiovascular outcomes was evaluated, with the aim to facilitate more accurate stratification and identification of high-risk individuals.

METHODS

From August 2013 to January 2014, 361 hemodialysis patients were prospectively enrolled. Lp-PLA2 activity and laboratory measures at baseline were quantified. Comorbidities and medications were recorded. All patients were followed until the end of April, 2022. The individual and combined effects of Lp-PLA2 activity and LDL-C on patient outcomes were examined. The association between Lp-PLA2 activity and all-cause mortality, cardiovascular mortality, and major adverse cardiovascular events (MACEs) was analyzed.

RESULTS

The median Lp-PLA2 activity was 481.2 U/L. In subjects with Lp-PLA2 activity over 481.2 U/L, significantly higher total cholesterol (4.89 vs. 3.98 mmol/L; P < 0.001), LDL-C (3.06 vs. 2.22 mmol/L; P < 0.001), and apolipoprotein B (0.95 vs. 0.75 mmol/L; P < 0.001) were observed. Over a median follow-up of 78.1 months, 182 patients died, with 77 cases identified as cardiovascular death, 88 MACEs happened. Cardiovascular mortality and MACEs, but not all-cause mortality, were significantly increased in the high Lp-PLA2 group. Cox regression analyses showed that high Lp-PLA2 activity was associated with cardiovascular mortality and MACE occurrence. After comprehensive adjustment, high Lp-PLA2 activity was independently associated with cardiovascular mortality(as a dichotomous variable: HR:2.57, 95%CI:1.58,4.18, P < 0.001; as a continuous variable: HR:1.25, 95%CI:1.10,1.41, P = 0.001) and MACEs(as a dichotomous variable: HR:2.17, 95%CI:1.39,3.40, P = 0.001; as a continuous variable: HR:1.20, 95%CI:1.07,1.36, P = 0.002). When participants were grouped by median Lp-PLA2 activity and LDL-C values, those with high Lp-PLA2 and low LDL-C had the highest CV mortality. The addition of Lp-PLA2 significantly improved reclassification (as a dichotomous variable NRI = 42.51%, 95%CI: 5.0%,61.33%; as a continuous variable, NRI = 33.32%, 95% CI: 7.47%,56.21%).

CONCLUSIONS

High Lp-PLA2 activity is an independent risk factor for cardiovascular mortality and MACEs occurrence in patients on hemodialysis. The combined measures of Lp-PLA2 and LDL-C help to identify individuals with a higher risk of cardiovascular death.

Effect of probiotic supplementation on lipoprotein-associated phospholipase A2 in type 2 diabetic patients: a randomized double blind clinical controlled trial

BACKGROUND

It has been recently reported that lipoprotein-associated phospholipase A2 (Lp-PLA2) may predict the risk of cardiovascular disease. The effect of multi-strain probiotics on Lp-PLA2 in patients with type 2 diabetes is still not clear.

AIMS

This study aimed to determine the effect of multi-strain probiotic supplementation on lipoprotein-associated phospholipase A2, and glycemic status, lipid profile, and body composition in patients with type 2 diabetes.

METHODS

In this randomized double-blind placebo-controlled clinical trial, 68 participants with type 2 diabetes, in the age group of 50-65 years, were recruited and randomly allocated to take either probiotic (n = 34) or placebo (n = 34) for 12 weeks. The primary outcome was lipoprotein-associated phospholipase A2, and secondary outcomes were glycemic parameters, lipid profile, anthropometric characters, and body composition (fat mass and fat-free mass).

RESULTS

There was a significant reduction in serum lipoprotein-associated phospholipase A2, in the probiotic group, it dropped by 6.4 units at the end of the study (p < 0.001) compared to the placebo group. Probiotic supplementation also resulted in a significant improvement in the hemoglobin A1c and high-density lipoprotein cholesterol 1.5% (p < 0.001) and 6 mg/dl (p 0.005), respectively. There were no significant changes in other outcomes.

CONCLUSION

Probiotic supplementation was beneficial for reducing Lp-PLA2 and hemoglobin-A1c and improving high-density lipoprotein cholesterol, which may suggest an improvement in the prognosis in patients with type 2 diabetes.

Causal Effect of Lipoprotein-Associated Phospholipase A2 Activity on Ischemic Stroke: A Mendelian Randomization Study

BACKGROUND

The relationship between ischemic stroke (IS) and lipoprotein-associated phospholipase A2 (Lp-PLA2) activity is still unclear, and there is a dearth of stratified research on the relationship between Lp-PLA2 activity and different IS subtypes. Therefore, Mendelian randomization (MR) was used in this study to examine the relationship between genetically proxied Lp-PLA2 activity and the risks of IS and its subtypes.

METHODS

Based on information from a meta-analysis of genome-wide association studies, which included 13,664 European people, five single nucleotide polymorphisms related to Lp-PLA2 activity were chosen as instrumental variables. Summary statistics information about the MEGESTROKE consortium with the European group (40,585 cases and 406,111 controls) include any IS (AIS; n = 34,217), large-artery stroke (LAS; n = 4,373), cardioembolic stroke (CES; n = 7,193), and small-vessel stroke (SVS; n = 5,386). In order to determine the causal relationships between Lp-PLA2 activity and IS as well as its subtypes, the inverse-variance-weighted (IVW) approach was chosen as the primary analysis. Significant estimates were then tested by sensitivity analysis to rule out heterogeneity and pleiotropy.

RESULTS

IVW showed that Lp-PLA2 activity was causally associated with LAS (odds ratio = 3.25, 95% confidence interval = 1.65-6.41, p = 0.0007) but not with other subtypes of stroke. Sensitivity analysis for causal estimates between Lp-PLA2 activity and LAS showed no significant heterogeneity or pleiotropy.

CONCLUSIONS

These MR analyses support a causal effect of Lp-PLA2 activity on LAS but not on AIS, CES, or SVS, which suggests that serum Lp-PLA2 activity might be a biomarker for prediction of LAS.

Use of 3D Printing Techniques to Fabricate Implantable Microelectrodes for Electrochemical Detection of Biomarkers in the Early Diagnosis of Cardiovascular and Neurodegenerative Diseases

This Review provides a comprehensive overview of 3D printing techniques to fabricate implantable microelectrodes for the electrochemical detection of biomarkers in the early diagnosis of cardiovascular and neurodegenerative diseases. Early diagnosis of these diseases is crucial to improving patient outcomes and reducing healthcare systems' burden. Biomarkers serve as measurable indicators of these diseases, and implantable microelectrodes offer a promising tool for their electrochemical detection. Here, we discuss various 3D printing techniques, including stereolithography (SLA), digital light processing (DLP), fused deposition modeling (FDM), selective laser sintering (SLS), and two-photon polymerization (2PP), highlighting their advantages and limitations in microelectrode fabrication. We also explore the materials used in constructing implantable microelectrodes, emphasizing their biocompatibility and biodegradation properties. The principles of electrochemical detection and the types of sensors utilized are examined, with a focus on their applications in detecting biomarkers for cardiovascular and neurodegenerative diseases. Finally, we address the current challenges and future perspectives in the field of 3D-printed implantable microelectrodes, emphasizing their potential for improving early diagnosis and personalized treatment strategies.

The incidence of subclinical atherosclerosis in subjects with low and moderate cardiovascular risk

BACKGROUND

The cardiovascular risk models and subclinical atherosclerotic indicators are both recommended for cardiovascular risk stratification. The accordance between the incidence of subclinical atherosclerosis and subjects with low and moderate cardiovascular risk is unclear.

HYPOTHESIS

Subjects with low and moderate cardiovascular risk have a lower incidence of subclinical atherosclerosis compared with subjects with high risk.

METHODS

Brachial-ankle pulse wave velocity (BaPWV) and brachial flow-mediated dilation (BFMD) were measured in 421 subjects without a history of atherosclerotic cardiovascular disease (ASCVD) from October 2016 to January 2020. All subjects were classified into low, moderate, and high risk based on Framingham and China-par risk models respectively.

RESULTS

Mean age was 57.05 ± 9.35 years and 248 (58.9%) were male. In subjects with low, moderate, and high risk assessed by Framingham and China-par risk models, the percentage of abnormal BaPWV ( > 1400 cm/s) was 42.9%, 70.1%, 85.7%, and 40.4%, 71.4%, 89.7%, respectively. Meanwhile, the percentage of abnormal BFMD ( ≤ 7%) was 43.8%, 68.5%, 77.3%, and 44.9%,72.1%, and 76.6%. According to Framingham-based high-risk categories, positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity for BaPWV abnormality were 85.7%, 39.4%, 36.1%, and 87.5%, respectively. For BFMD abnormality, the values were 77.3%, 40.1%, 34.1%, and 81.8%, respectively. According to China-par high-risk categories, the values for BaPWV abnormality were 89.7%, 43.8%, 45.6%, and 89.0%, respectively. For BFMD abnormality, the values were 76.6%, 41.3%, 40.7%, and 77%, respectively. In multivariate analysis, age and blood pressure were the independent predictors for subclinical atherosclerosis in subjects with low-moderate risk.

CONCLUSIONS

More than one-half of subjects with low and moderate risk already have detectable subclinical atherosclerosis, indicating higher cardiovascular risk beyond the traditional stratification.

Changes in Choline Metabolites and Ceramides in Response to a DASH-Style Diet in Older Adults

This feeding trial evaluated the impact of the Dietary Approaches to Stop Hypertension diet on changes in plasma choline, choline metabolites, and ceramides in obese older adults; 28 adults consumed 3oz (n = 15) or 6oz (n = 13) of beef within a standardized DASH diet for 12 weeks. Plasma choline, betaine, methionine, dimethylglycine (DMG), phosphatidylcholine (PC), lysophosphotidylcholine (LPC), sphingomyelin, trimethylamine-N-oxide (TMAO), L-carnitine, ceramide, and triglycerides were measured in fasted blood samples. Plasma LPC, sphingomyelin, and ceramide species were also quantified. In response to the study diet, with beef intake groups combined, plasma choline decreased by 9.6% (p = 0.012); DMG decreased by 10% (p = 0.042); PC decreased by 51% (p < 0.001); total LPC increased by 281% (p < 0.001); TMAO increased by 26.5% (p < 0.001); total ceramide decreased by 22.1% (p < 0.001); and triglycerides decreased by 18% (p = 0.021). All 20 LPC species measured increased (p < 0.01) with LPC 16:0 having the greatest response. Sphingomyelin 16:0, 18:0, and 18:1 increased (all p < 0.001) by 10.4%, 22.5%, and 24%, respectively. In contrast, we observed that sphingomyelin 24:0 significantly decreased by 10%. Ceramide 22:0 and 24:0 decreased by 27.6% and 10.9% (p < 0.001), respectively, and ceramide 24:1 increased by 36.8% (p = 0.013). Changes in choline and choline metabolites were in association with anthropometric and cardiometabolic outcomes. These findings show the impact of the DASH diet on choline metabolism in older adults and demonstrate the influence of diet to modify circulating LPC, sphingomyelin, and ceramide species.

Current Biomarkers for Carotid Artery Stenosis: A Comprehensive Review of the Literature

Carotid artery stenosis (CAS), an atherosclerotic disease of the carotid artery, is one of the leading causes of transient ischemic attacks (TIA) and cerebrovascular attacks (CVA). The atherogenic process of CAS affects a wide range of physiological processes, such as inflammation, endothelial cell function, smooth muscle cell migration and many more. The current gold-standard test for CAS is Doppler ultrasound; however, there is yet to be determined a strong, clinically validated biomarker in the blood that can diagnose patients with CAS and/or predict adverse outcomes in such patients. In this comprehensive literature review, we evaluated all of the current research on plasma and serum proteins that are current contenders for biomarkers for CAS. In this literature review, 36 proteins found as potential biomarkers for CAS were categorized in to the following nine categories based on protein function: (1) Inflammation and Immunity, (2) Lipid Metabolism, (3) Haemostasis, (4) Cardiovascular Markers, (5) Markers of Kidney Function, (6) Bone Health, (7) Cellular Structure, (8) Growth Factors, and (9) Hormones. This literature review is the most up-to-date and current comprehensive review of research on biomarkers of CAS, and the only review that demonstrated the several pathways that contribute to the initiation and progression of the disease. With this review, future studies can determine if any new markers, or a panel of the proteins explored in this study, may be contenders as diagnostic or prognostic markers for CAS.

New Insights into Pathophysiology and New Risk Factors for ACS

Cardiovascular disease still represents the main cause of mortality worldwide. Despite huge improvements, atherosclerosis persists as the principal pathological condition, both in stable and acute presentation. Specifically, acute coronary syndromes have received substantial research and clinical attention in recent years, contributing to improve overall patients' outcome. The identification of different evolution patterns of the atherosclerotic plaque and coronary artery disease has suggested the potential need of different treatment approaches, according to the mechanisms and molecular elements involved. In addition to traditional risk factors, the finer portrayal of other metabolic and lipid-related mediators has led to higher and deep knowledge of atherosclerosis, providing potential new targets for clinical management of the patients. Finally, the impressive advances in genetics and non-coding RNAs have opened a wide field of research both on pathophysiology and the therapeutic side that are extensively under investigation.

Intravascular imaging assessment of pharmacotherapies targeting atherosclerosis: advantages and limitations in predicting their prognostic implications

Intravascular imaging has been often used over the recent years to examine the efficacy of emerging therapies targeting plaque evolution. Serial intravascular ultrasound, optical coherence tomography, or near-infrared spectroscopy-intravascular ultrasound studies have allowed us to evaluate the effects of different therapies on plaque burden and morphology, providing unique mechanistic insights about the mode of action of these treatments. Plaque burden reduction, a decrease in necrotic core component or macrophage accumulation-which has been associated with inflammation-and an increase in fibrous cap thickness over fibroatheromas have been used as surrogate endpoints to assess the value of several drugs in inhibiting plaque evolution and improving clinical outcomes. However, some reports have demonstrated weak associations between the effects of novel treatments on coronary atheroma and composition and their prognostic implications. This review examines the value of invasive imaging in assessing pharmacotherapies targeting atherosclerosis. It summarizes the findings of serial intravascular imaging studies assessing the effects of different drugs on atheroma burden and morphology and compares them with the results of large-scale trials evaluating their impact on clinical outcome. Furthermore, it highlights the limited efficacy of established intravascular imaging surrogate endpoints in predicting the prognostic value of these pharmacotherapies and introduces alternative imaging endpoints based on multimodality/hybrid intravascular imaging that may enable more accurate assessment of the athero-protective and prognostic effects of emerging therapies.

Correlation between smoking and serum lipoprotein-associated phospholipase A2 level in overweight and obese men

OBJECTIVES

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a vaso-specific inflammatory marker that exacerbates atherosclerotic through inflammatory responses. It can be used to predict the occurrence of adverse cardiovascular events and to assess the residual risk of cardiovascular diseases. This study aims to investigate the correlation between smoking and serum Lp-PLA2 levels in overweight and obese men, and to provide evidence for preventing the cardiovascular diseases.

METHODS

Male subjects, who participated in health examination at the Health Management Center, Third Xiangya Hospital, Central South University from May 1, 2020 to April 30, 2021, were selected. The smoking status and other information were collected by the Self-test Scale of Physical Examination. According to the smoking status, they were divided into a never-smoking group, a current smoking group, a quit smoking group and a passive smoking group. According to the daily smoking amount, the current smoking subjects were divided into a <10 cigarettes group, a 10 to 20 cigarettes group, a 21 to 30 cigarettes group, and a >30 cigarettes group. According to the smoking years, the current smoking subjects were divided into a <5 years group, a 5 to 10 years group, a 11 to 20 years group, and a >20 years group.Serum Lp-PLA2 levels and other clinical indexes in different smoking groups were measured and compared, the correlation between smoking and serum Lp-PLA2 levels in overweight and obese men was analyzed by logistic regression analysis.

RESULTS

Serum Lp-PLA2 levels were significantly different between the never-smoking group and the current smoking group (P<0.05). Logistic regression analysis showed that, before adjusting other influencing factors and in terms of smoking status, the current smoking group (OR=1.81, 95% CI 1.27 to 2.58, P<0.01) and the quit smoking group (OR=2.09, 95% CI 1.12 to 3.90, P<0.05) were positively correlated with serum Lp-PLA2 levels compared with the never-smoking group, while the passive smoking group had no correlation with serum Lp-PLA2 levels (OR=1.27, 95% CI 0.59 to 2.73, P>0.05). In terms of daily smoking amount, the 10 to 20 cigarettes group (OR=2.09, 95% CI 1.40 to 3.12, P<0.001) and the 21 to 30 cigarettes group (OR=1.98, 95% CI 1.22 to 3.20, P<0.01) were positively correlated with serum Lp-PLA2 levels compared with the never-smoking group, while the <10 cigarettes group (OR=1.45, 95% CI 0.81 to 2.60, P>0.05) and the >30 cigarettes group (OR=1.17, 95% CI 0.60 to 2.28, P>0.05) had no correlation with serum Lp-PLA2 levels. In terms of smoking years, the 5 to 10 years group (OR=1.94, 95% CI 1.07 to 3.53, P<0.05), the 11 to 20 years group (OR=2.06, 95% CI 1.33 to 3.18, P<0.01), and the >20 years group (OR=1.66, 95% CI 1.11 to 2.47, P<0.05) were positively correlated with serum Lp-PLA2 levels compared with the never-smoking group, while the <5 years group had no correlation with serum Lp-PLA2 levels (OR=1.12, 95% CI 0.38 to 3.33, P>0.05). After adjusting for age and other indicators, the correlation between smoking years and serum Lp-PLA2 levels was the same as before adjustment among the above smoking groups, except that the correlation between the smoking 5 to 10 years group and serum Lp-PLA2 levels was not significant (OR=1.77, 95% CI 0.95 to 3.29, P>0.05).

CONCLUSIONS

Smoking is correlated with serum Lp-PLA2 levels in overweight and obese men.

Lipids at the Nexus between Cerebrovascular Disease and Vascular Dementia: The Impact of HDL-Cholesterol and Ceramides

Cerebrovascular diseases and the subsequent brain hypoperfusion are at the basis of vascular dementia. Dyslipidemia, marked by an increase in circulating levels of triglycerides and LDL-cholesterol and a parallel decrease in HDL-cholesterol, in turn, is pivotal in promoting atherosclerosis which represents a common feature of cardiovascular and cerebrovascular diseases. In this regard, HDL-cholesterol has traditionally been considered as being protective from a cardiovascular and a cerebrovascular prospective. However, emerging evidence suggests that their quality and functionality play a more prominent role than their circulating levels in shaping cardiovascular health and possibly cognitive function. Furthermore, the quality of lipids embedded in circulating lipoproteins represents another key discriminant in modulating cardiovascular disease, with ceramides being proposed as a novel risk factor for atherosclerosis. This review highlights the role of HDL lipoprotein and ceramides in cerebrovascular diseases and the repercussion on vascular dementia. Additionally, the manuscript provides an up-to-date picture of the impact of saturated and omega-3 fatty acids on HDL circulating levels, functionality and ceramide metabolism.

Lp-PLA2 (Lipoprotein-Associated Phospholipase A2) Deficiency Lowers Cholesterol Levels and Protects Against Atherosclerosis in Rabbits

BACKGROUND

Elevated plasma Lp-PLA₂ (lipoprotein-associated phospholipase A₂) activity is closely associated with an increased risk of cardiovascular events. However, whether and how Lp-PLA₂ is directly involved in the pathogenesis of atherosclerosis is still unclear. To examine the hypothesis that Lp-PLA₂ could be a potential preventative target of atherosclerosis, we generated Lp-PLA₂ knockout rabbits and investigated the pathophysiological functions of Lp-PLA₂.

METHODS

Lp-PLA₂ knockout rabbits were generated using CRISPR/Cas9 system to assess the role of Lp-PLA₂ in plasma lipids regulation and identify its underlying molecular mechanisms. Homozygous knockout rabbits along with wild-type rabbits were fed a cholesterol-rich diet for up to 14 weeks and their atherosclerotic lesions were compared. Moreover, the effects of Lp-PLA₂ deficiency on the key cellular behaviors in atherosclerosis were assessed in vitro.

RESULTS

When rabbits were fed a standard diet, Lp-PLA₂ deficiency led to a significant reduction in plasma lipids. The decreased protein levels of SREBP2 (sterol regulatory element-binding protein 2) and HMGCR (3-hydroxy-3-methylglutaryl coenzyme A reductase) in livers of homozygous knockout rabbits indicated that the cholesterol biosynthetic pathway was impaired with Lp-PLA₂ deficiency. In vitro experiments further demonstrated that intracellular Lp-PLA₂ efficiently enhanced SREBP2-related cholesterol biosynthesis signaling independently of INSIGs (insulin-induced genes). When fed a cholesterol-rich diet, homozygous knockout rabbits exhibited consistently lower level of hypercholesterolemia, and their aortic atherosclerosis lesions were significantly reduced by 60.2% compared with those of wild-type rabbits. The lesions of homozygous knockout rabbits were characterized by reduced macrophages and the expression of inflammatory cytokines. Macrophages of homozygous knockout rabbits were insensitive to M1 polarization and showed reduced DiI-labeled lipoprotein uptake capacity compared with wild-type macrophages. Lp-PLA₂ deficiency also inhibited the adhesion between monocytes and endothelial cells.

CONCLUSIONS

These results demonstrate that Lp-PLA₂ plays a causal role in regulating blood lipid homeostasis and Lp-PLA₂ deficiency protects against dietary cholesterol-induced atherosclerosis in rabbits. Lp-PLA₂ could be a potential target for the prevention of atherosclerosis.

Milk metabolomics analyses of lactating dairy cows with divergent residual feed intake reveals physiological underpinnings and novel biomarkers

The opportunity to select for feed efficient cows has been limited by inability to cost-effectively record individual feed efficiency on an appropriate scale. This study investigated the differences in milk metabolite profiles between high- and low residual feed intake (RFI) categories and identified biomarkers of residual feed intake and models that can be used to predict residual feed intake in lactating Holsteins. Milk metabolomics analyses were undertaken at early, mid and late lactation stages and residual feed intake was calculated in 72 lactating dairy cows. Cows were ranked and grouped into high residual feed intake (RFI >0.5 SD above the mean, n = 20) and low residual feed intake (RFI <0.5 SD below the mean, n = 20). Milk metabolite profiles were compared between high residual feed intake (least efficient) and low residual feed intake (most efficient) groups. Results indicated that early lactation was predominantly characterized by significantly elevated levels of medium chain acyl carnitines and glycerophospholipids in high residual feed intake cows. Citrate cycle and glycerophospholipid metabolism were the associated pathways enriched with the significantly different metabolites in early lactation. At mid lactation short and medium chain acyl carnitines, glycerophospholipids and amino acids were the main metabolite groups differing according to residual feed intake category. Late lactation was mainly characterized by increased levels of amino acids in high residual feed intake cows. Amino acid metabolism and biosynthesis pathways were enriched for metabolites that differed between residual feed intake groups at the mid and late lactation stages. Receiver operating characteristic curve analysis identified candidate biomarkers: decanoylcarnitine (area under the curve: AUC = 0.81), dodecenoylcarnitine (AUC = 0.81) and phenylalanine (AUC = 0.85) at early, mid and late stages of lactation, respectively. Furthermore, panels of metabolites predicted residual feed intake with validation coefficient of determination (R ²) of 0.65, 0.37 and 0.60 at early, mid and late lactation stages, respectively. The study sheds light on lactation stage specific metabolic differences between high-residual feed intake and low-residual feed intake lactating dairy cows. Candidate biomarkers that distinguished divergent residual feed intake groups and panels of metabolites that predict individual residual feed intake phenotypes were identified. This result supports the potential of milk metabolites to select for more efficient cows given that traditional residual feed intake phenotyping is costly and difficult to conduct in commercial farms.

Epidemiological analysis of coronary heart disease and its main risk factors: are their associations multiplicative, additive, or interactive?

OBJECTIVE

The purpose of this study was to discover how considering multiplicative, additive, and interactive effects modifies results of a prospective cohort study on coronary heart disease (CHD) incidence and its main risk factors.

MATERIAL AND METHODS

The Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study provided the study material, 2682 Eastern Finnish middle-aged men, followed since the 1980s. We applied multiplicative and additive survival models together with different statistical metrics and confidence intervals for risk ratios and risk differences to estimate the nature of associations.

RESULTS

The mean (SD) follow-up time among men who were free of CHD at baseline (n = 1958) was 21.4 (10.4) years, and 717 (37%) of them had the disease and 301 (15%) died for CHD before the end of follow-up. All tested non-modifiable and modifiable risk factors statistically significantly predicted CHD incidence. We detected three interactions: circulating low-density lipoprotein cholesterol (LDL-C) × age, obesity × age, and obesity × smoking of which LDL-C × age was the most evident one. High LDL-C increased the risk of CHD more among men younger than 50 [risk ratio (RR) 2.10] than those older than 50 (RR 1.22). LDL-C status was the only additive covariate. The additive effect of high LDL-C increased almost linearly up to 18 years and then reached a plateau. The simple multiplicative survival model stressed glycemic status as the strongest modifiable risk factor for developing CHD [hazard ratio (HR) for diabetes vs. normoglycemia was 2.69], whereas the model considering interactions and time dependence emphasised the role of LDL-C status (HR for high LDL-C vs. lower than borderline was 4.43). Age was the strongest non-modifiable predictor.

CONCLUSIONS

Including covariate interactions and time dependence in survival models potentially refine results of epidemiological analyses and ease to define the order of importance across CHD risk factors. KEY MESSAGESIncluding covariate interactions and time dependence in survival models potentially refine results of epidemiological analyses on coronary heart disease.Including covariate interactions and time dependence in survival models potentially ease to define the order of importance across coronary heart disease risk factors.

Oxidized phospholipids and lipoprotein-associated phospholipase A2 (Lp-PLA2 ) in atherosclerotic cardiovascular disease: An update

Inflammation and oxidative stress conditions lead to a variety of oxidative modifications of lipoprotein phospholipids implicated in the occurrence and development of atherosclerotic lesions. Lipoprotein-associated phospholipase A2 (Lp-PLA2 ) is established as an independent risk biomarker of atherosclerosis-related cardiovascular disease (ASCVD) and mediates vascular inflammation through the regulation of lipid metabolism in the blood and in atherosclerotic lesions. Lp-PLA2 is associated with low- and high-density lipoproteins and Lipoprotein (a) in human plasma and specifically hydrolyzes oxidized phospholipids involved in oxidative stress modification. Several oxidized phospholipids (OxPLs) subspecies can be detoxified through enzymatic degradation by Lp-PLA2 activation, forming lysophospholipids and oxidized non-esterified fatty acids (OxNEFAs). Lysophospholipids promote the expression of adhesion molecules, stimulate cytokines production (TNF-α, IL-6), and attract macrophages to the arterial intima. The present review article discusses new data on the functional roles of OxPLs and Lp-PLA2 associated with lipoproteins.

Temporal associations between leukocytes DNA methylation and blood lipids: a longitudinal study

BACKGROUND

The associations between blood lipids and DNA methylation have been investigated in epigenome-wide association studies mainly among European ancestry populations. Several studies have explored the direction of the association using cross-sectional data, while evidence of longitudinal data is still lacking.

RESULTS

We tested the associations between peripheral blood leukocytes DNA methylation and four lipid measures from Illumina 450 K or EPIC arrays in 1084 participants from the Chinese National Twin Registry and replicated the result in 988 participants from the China Kadoorie Biobank. A total of 23 associations of 19 CpG sites were identified, with 4 CpG sites located in or adjacent to 3 genes (TMEM49, SNX5/SNORD17 and CCDC7) being novel. Among the validated associations, we conducted a cross-lagged analysis to explore the temporal sequence and found temporal associations of methylation levels of 2 CpG sites with triglyceride and 2 CpG sites with high-density lipoprotein-cholesterol (HDL-C) in all twins. In addition, methylation levels of cg11024682 located in SREBF1 at baseline were temporally associated with triglyceride at follow-up in only monozygotic twins. We then performed a mediation analysis with the longitudinal data and the result showed that the association between body mass index and HDL-C was partially mediated by the methylation level of cg06500161 (ABCG1), with a mediation proportion of 10.1%.

CONCLUSIONS

Our study indicated that the DNA methylation levels of ABCG1, AKAP1 and SREBF1 may be involved in lipid metabolism and provided evidence for elucidating the regulatory mechanism of lipid homeostasis.

Alterations of HDL's to piHDL's Proteome in Patients with Chronic Inflammatory Diseases, and HDL-Targeted Therapies

Chronic inflammatory diseases, such as rheumatoid arthritis, steatohepatitis, periodontitis, chronic kidney disease, and others are associated with an increased risk of atherosclerotic cardiovascular disease, which persists even after accounting for traditional cardiac risk factors. The common factor linking these diseases to accelerated atherosclerosis is chronic systemic low-grade inflammation triggering changes in lipoprotein structure and metabolism. HDL, an independent marker of cardiovascular risk, is a lipoprotein particle with numerous important anti-atherogenic properties. Besides the essential role in reverse cholesterol transport, HDL possesses antioxidative, anti-inflammatory, antiapoptotic, and antithrombotic properties. Inflammation and inflammation-associated pathologies can cause modifications in HDL's proteome and lipidome, transforming HDL from atheroprotective into a pro-atherosclerotic lipoprotein. Therefore, a simple increase in HDL concentration in patients with inflammatory diseases has not led to the desired anti-atherogenic outcome. In this review, the functions of individual protein components of HDL, rendering them either anti-inflammatory or pro-inflammatory are described in detail. Alterations of HDL proteome (such as replacing atheroprotective proteins by pro-inflammatory proteins, or posttranslational modifications) in patients with chronic inflammatory diseases and their impact on cardiovascular health are discussed. Finally, molecular, and clinical aspects of HDL-targeted therapies, including those used in therapeutical practice, drugs in clinical trials, and experimental drugs are comprehensively summarised.

Increased sedentary time and decreased physical activity increases lipoprotein associated phospholipase A2 in obese individuals

BACKGROUND AND AIMS

Lipoprotein-associated Phospholipase A₂ (Lp-PLA₂) is a protein produced by inflammatory cells in circulation and is associated with cardiovascular disease (CVD) risk. Physical activity (PA) is known to reduce inflammation and risk for CVD. However, Lp-PLA₂ has yet to be examined in relation to PA and sedentary time. The purpose of this study was to determine if PA and sedentary time impacts Lp-PLA₂ mass. A total of 25 subjects with an average BMI of 30.6 ± 5.7 were included in the data analysis.

METHODS AND RESULTS

Data collected included anthropometric data, Lp-PLA₂ mass, peak oxygen uptake (VO₂peak), resting heart rate and blood pressure, obstructive sleep apnea (OSA) risk, and assessment of PA using an accelerometer. Sedentary minutes per day was positively associated with Lp-PLA₂ (r = 0.41, P < 0.05). Light intensity PA was negatively associated (r = -0.51. P = 0.01) with Lp-PLA₂. When subjects were divided into 2-quantiles by Lp-PLA₂, the group with the higher Lp-PLA₂ mass accumulated more sedentary time per day (P < 0.001) and less light intensity PA per day (P = 0.001). OSA risk and Lp-PLA₂ showed no relationship. Sedentary behavior was higher, and light intensity PA was lower in subjects with hiLp-PLA₂ mass. No difference was seen in moderate-to-vigorous intensity PA or steps per day.

CONCLUSIONS

This suggests that, total PA habits, including time spent sedentary and lower intensity PA, impacts the levels of Lp-PLA₂, an important inflammatory marker and marker of CVD risk.

Association Between High-Sensitivity C-Reactive Protein and Prognosis in Different Periods After Ischemic Stroke or Transient Ischemic Attack

Background

The aim of this study was to investigate the association between hsCRP (high‐sensitivity C‐reactive protein) and prognosis over time after stroke onset.

Methods and Results

In this prespecified prospective substudy of the Third China National Stroke Registry, a total of 9438 patients with acute ischemic stroke or transient ischemic attack and measured hsCRP were included. Patients were categorized into 3 groups according to the sampling time after index onset (<24 hours, 24–72 hours, 72 hours–8 days). The outcomes consisted of stroke recurrence and combined vascular events within 1 year, and dependence or death defined as modified Rankin Scale score of 3 to 6 at 1 year. The associations between hsCRP and outcomes in different groups were analyzed by using Cox proportional hazards and logistic regression models. The median levels of hsCRP within 24 hours, between 24 and 72 hours and between 72 hours and 8 days were 2.01, 1.72, and 1.72 mg/L, respectively (P < 0.05). Compared with the bottom quartile, patients in the top quartile measured within 72 hours were at increased risk of recurrent stroke (<24 hours: adjusted hazard ratio [HR], 1.57 [95% CI, 1.05–2.35], P = 0.03; 24–72 hours: adjusted HR, 1.60 [95% CI, 1.18–2.17], P = 0.003). Association was attenuated after further adjusting for the Org 10 172 test in the Treatment of Acute Stroke classification (<24 hours: adjusted HR, 1.51 [95% CI, 1.01–2.27]; P = 0.05; 24–72 hours: adjusted HR, 1.55 [95% CI, 1.14–2.10]; P = 0.01). The association only existed in patients with large‐artery atherosclerosis (adjusted HR, 1.68 [95% CI, 1.06–2.64]; P = 0.03). However, the association was not found in the hsCRP level measured between 72 hours and 8 days. Similar results were found for the outcome of combined vascular events. Additionally, hsCRP levels measured between 24 and 72 hours were associated with an increased risk of poor functional outcomes.

Conclusions

Elevated levels of hsCRP measured in the first 72 hours after ischemic stroke or transient ischemic attack but not 72 hours to 8 days, were associated with an increased risk of 1‐year stroke recurrence.

Elevated Lipoprotein-Associated Phospholipase A2 Is Associated With Intracranial Atherosclerosis

Background

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an inflammatory factor in the pathogenesis of atherosclerotic plaque and is associated with an increased risk of ischemic stroke. Whether Lp-PLA2 is associated with stenosis subtypes in acute ischemic stroke (AIS) has not been investigated.

Methods

A total of 126 eligible AIS patients were divided into four groups: (1) no cerebral artery stenosis (NCS); (2) intracranial artery stenosis (ICAS); (3) extracranial artery stenosis (ECAS); and (4) combined intracranial and extracranial artery stenosis (IECS). Associations between serum Lp-PLA2 levels and the stenosis subtypes were assessed.

Results

The ICAS group had a lower frequency of dyslipidemia as compared to the NCS group and the IECS group (35.3% vs. 70% vs. 71.8%, respectively, p = 0.001) and was more likely to be symptomatic than the ECAS group (76.5% vs. 43.8%, respectively, p = 0.014). Lp-PLA2 levels in the ICAS group were 112.2 ± 66.8 μg/L which are, higher than those in the NCS, ECAS, and IECS groups (81.7 ± 38.5, 106.1 ± 57.8, 89.3 ± 52.2 μg/L, respectively, p = 0.025). In the third and fourth quartiles of Lp-PLA2 levels, stenosis had occurred more frequently in the ICAS group than in the other three groups (third Q: 50.0% vs. 3.1% vs. 28.1% vs. 18.8%, p = 0.002; fourth Q: 48.4% vs. 16.1% vs. 25.8% vs. 9.7%, p = 0.014). Lp-PLA2 levels were higher in patients with more or severe stenosis in the ICAS group.

Conclusions

Elevated Lp-PLA2 levels were differentially associated with increased risk in AIS patients with ICAS compared to those with ECAS or no stenosis. Lp-PLA2 may be a promising biomarker and potential therapeutic target for ICAS.

Mendelian randomization analysis of 37 clinical factors and coronary artery disease in East Asian and European populations

BACKGROUND

Coronary artery disease (CAD) remains the leading cause of mortality worldwide despite enormous efforts devoted to its prevention and treatment. While many genetic loci have been identified to associate with CAD, the intermediate causal risk factors and etiology have not been fully understood. This study assesses the causal effects of 37 heritable clinical factors on CAD in East Asian and European populations.

METHODS

We collected genome-wide association summary statistics of 37 clinical factors from the Biobank Japan (42,793 to 191,764 participants) and the UK Biobank (314,658 to 442,817 participants), paired with summary statistics of CAD from East Asians (29,319 cases and 183,134 controls) and Europeans (91,753 cases and 311,344 controls). These clinical factors covered 12 cardiometabolic traits, 13 hematological indices, 7 hepatological and 3 renal function indices, and 2 serum electrolyte indices. We performed univariable and multivariable Mendelian randomization (MR) analyses in East Asians and Europeans separately, followed by meta-analysis.

RESULTS

Univariable MR analyses identified reliable causal evidence (P < 0.05/37) of 10 cardiometabolic traits (height, body mass index [BMI], blood pressure, glycemic and lipid traits) and 4 other clinical factors related to red blood cells (red blood cell count [RBC], hemoglobin, hematocrit) and uric acid (UA). Interestingly, while generally consistent, we identified population heterogeneity in the causal effects of BMI and UA, with higher effect sizes in East Asians than those in Europeans. After adjusting for cardiometabolic factors in multivariable MR analysis, red blood cell traits (RBC, meta-analysis odds ratio 1.07 per standard deviation increase, 95% confidence interval 1.02-1.13; hemoglobin, 1.10, 1.03-1.16; hematocrit, 1.10, 1.04-1.17) remained significant (P < 0.05), while UA showed an independent causal effect in East Asians only (1.12, 1.06-1.19, P = 3.26×10-5).

CONCLUSIONS

We confirmed the causal effects of 10 cardiometabolic traits on CAD and identified causal risk effects of RBC, hemoglobin, hematocrit, and UA independent of traditional cardiometabolic factors. We found no causal effects for 23 clinical factors, despite their reported epidemiological associations. Our findings suggest the physiology of red blood cells and the level of UA as potential intervention targets for the prevention of CAD.

Lp-PLA2 as a biomarker and its possible associations with SARS-CoV-2 infection

Lp-PLA2 is an enzyme encoded by the PLA2G7 gene located at chromosome 6p12-21, which is included in different signal transduction pathways. The potential of serum levels of Lp-PLA2 as a marker of inflammation quantifying cardio-metabolic risk, renal impairment and oxidative stress has been explored in earlier studies. It has also been used in chronic obstructive pulmonary disease, hepatic disease, metabolic conditions and exercise tolerance. Additionally, it shows promising evidence for the assessment of risk for certain cardiovascular conditions in otherwise seemingly healthy individuals. COVID-19 has affected life and the economy globally. The identification of biomarkers to assess the sickness and treatment plan is the need of the hour. This review summarizes the pathophysiological inter-relationship between serum levels of Lp-PLA2 and COVID-19. The authors hypothesize that the estimation of Lp-PLA2 levels may help in the early identification of risk and thus may play a beneficial role in the proactive management of COVID-19.

Cardiovascular Biomarkers: Lessons of the Past and Prospects for the Future

Cardiovascular diseases (CVDs) are a major healthcare burden on the population worldwide. Early detection of this disease is important in prevention and treatment to minimise morbidity and mortality. Biomarkers are a critical tool to either diagnose, screen, or provide prognostic information for pathological conditions. This review discusses the historical cardiac biomarkers used to detect these conditions, discussing their application and their limitations. Identification of new biomarkers have since replaced these and are now in use in routine clinical practice, but still do not detect all disease. Future cardiac biomarkers are showing promise in early studies, but further studies are required to show their value in improving detection of CVD above the current biomarkers. Additionally, the analytical platforms that would allow them to be adopted in healthcare are yet to be established. There is also the need to identify whether these biomarkers can be used for diagnostic, prognostic, or screening purposes, which will impact their implementation in routine clinical practice.

Stepper-Based Training Improves Monocyte-Platelet Aggregation and Thrombin Generation in Nonambulatory Hemiplegic Patients

PURPOSE

Nonambulatory stroke patients are extremely sedentary, but most available data concerning exercise training in stroke patients are related to ambulatory patients. This study aimed to investigate the efficacy of stepper-based exercise training on cardiopulmonary fitness, monocyte subtypes, and associated monocyte-platelet aggregates (MPA) and thrombin generation (TrG) in nonambulatory hemiplegic patients with ischemic stroke.

METHOD

Thirty-eight patients were randomized into exercise training (ET, n = 20) and usual care (UC, n = 18) groups. The ET underwent supervised exercise training (60% peak work rate) using a recumbent stepper for two to four sessions per week and 36 sessions in total. In addition, 12 healthy participants were enrolled as healthy controls. Monocyte characteristics, MPA, and plasma TrG kinetics were determined before and after intervention by flow cytometry and calibrated automated thrombogram® (CAT).

RESULTS

Seventeen and 15 patients completed the protocol in the ET and UC groups. Peak V̇O2 improved in ET (15.7 ± 4.8 vs 18.9 ± 5.3 mL·min-1·kg-1, +20%), so did the phase angle of the hemiplegic limbs. The counts of total MPA and MPA associated with three monocyte subtypes, alongside CD42b expression all declined in ET with subtypes 2 and 1 being the most prominent. Macrophage inflammatory protein 1β (MIP-1 β) level also declined. The TrG kinetics was attenuated after ET by delaying initiation and reducing the rising slope and peak of thrombin production. In UC, no difference was revealed in the pre-post comparison.

CONCLUSIONS

Stepper-based ET is feasible in nonambulatory hemiplegic patients and is effective in improving aerobic fitness. Moreover, it decreases heteroaggregation of monocytes with platelets, especially in monocyte subtypes 2 and 1. Thrombin generation was also attenuated. Hence, stepper-based ET may be incorporated in the rehabilitation of nonambulatory hemiplegic patients.

Diagnostic circulating biomarkers to detect vision-threatening diabetic retinopathy: Potential screening tool of the future?

With the increasing prevalence of diabetes in developing and developed countries, the socio-economic burden of diabetic retinopathy (DR), the leading complication of diabetes, is growing. Diabetic retinopathy (DR) is currently one of the leading causes of blindness in working-age adults worldwide. Robust methodologies exist to detect and monitor DR; however, these rely on specialist imaging techniques and qualified practitioners. This makes detecting and monitoring DR expensive and time-consuming, which is particularly problematic in developing countries where many patients will be remote and have little contact with specialist medical centres. Diabetic retinopathy (DR) is largely asymptomatic until late in the pathology. Therefore, early identification and stratification of vision-threatening DR (VTDR) is highly desirable and will ameliorate the global impact of this disease. A simple, reliable and more cost-effective test would greatly assist in decreasing the burden of DR around the world. Here, we evaluate and review data on circulating protein biomarkers, which have been verified in the context of DR. We also discuss the challenges and developments necessary to translate these promising data into clinically useful assays, to detect VTDR, and their potential integration into simple point-of-care testing devices.

Associations of genetic variants of lysophosphatidylcholine metabolic enzymes with levels of serum lipids

OBJECTIVE

Metabolic disturbance of lysophosphatidylcholine (LPC) is related with dyslipidemia. Therefore, eight single-nucleotide polymorphisms (SNPs) were selected from LPC metabolic enzymes to study their associations with obesity and serum levels of lipids.

METHODS

A total of 3305 children were recruited from four independent studies. Eight SNPs of LPC metabolic enzymes were selected and genotyped with the matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). The multivariable linear regression model was applied to detect the associations of eight SNPs with obesity-related phenotypes and levels of lipids in each study. Meta-analyses were used to combine the results of four studies.

RESULTS

Only SNP rs4420638 of APOC-1 gene was associated with serum lipids even after Bonferroni correction. The rs4420638 was positively associated with TC (β = 0.15, P = 8.59 × 10^-9) and low-density-lipoprotein-cholesterol (LDL-C, β = 0.16, P = 9.98 × 10^-14) individually.

CONCLUSION

The study firstly revealed the association between APOC-1/rs4420638 and levels of serum lipids in Chinese children, providing evidence for susceptible gene variants of dyslipidemia.

Air pollution and biomarkers of cardiovascular disease and inflammation in the Malmö Diet and Cancer cohort

INTRODUCTION

Air pollution is associated with increased risk of cardiovascular disease, possibly through chronic systemic inflammation that promotes the progression of atherosclerosis and the risk of cardiovascular events. This study aimed to investigate the associations between air pollution and established biomarkers of inflammation and cardiovascular disease.

METHODS

The Cardiovascular Subcohort of the Malmö Diet and Cancer cohort includes 6103 participants from the general population of Malmö, Sweden. The participants were recruited 1991-1994. Annual mean residential exposure to particulate matter < 2.5 and < 10 μm (PM_2.5 and PM₁₀), and nitrogen oxides (NO_x) at year of recruitment were assigned from dispersion models. Blood samples collected at recruitment, including blood cell counts, and biomarkers (lymphocyte- and neutrophil counts, C-reactive protein (CRP), soluble urokinase-type plasminogen activator receptor (suPAR), lipoprotein-associated phospholipase A₂ (Lp-PLA₂), ceruloplasmin, orosomucoid, haptoglobin, complement-C3, and alpha-1-antitrypsin) were analyzed. Multiple linear regression models were used to investigate the cross-sectional associations between air pollutants and biomarkers.

RESULTS

The mean annual exposure levels in the cohort were only slightly or moderately above the new WHO guidelines of 5 μg/m³ PM_2.5 (10.5 μg/m³ PM_2.5). Residential PM_2.5 exposure was associated with increased levels of ceruloplasmin, orosomucoid, C3, alpha-1-antitrypsin, haptoglobin, Lp-PLA₂ and the neutrophil-lymphocyte ratio. Ceruloplasmin, orosomucoid, C3 and alpha-1-antitrypsin were also positively associated with PM₁₀. There were no associations between air pollutants and suPAR, leukocyte counts or CRP. The associations between particles and biomarkers were still significant after removing outliers and adjustment for CRP levels. The associations were more prominent in smokers.

CONCLUSION

Long-term residential exposure to moderate levels of particulate air pollution was associated with several biomarkers of inflammation and cardiovascular disease. This supports inflammation as a mechanism behind the association between air pollution and cardiovascular disease.

Effects of flaxseed consumption on plasma lipids, lipoprotein-associated phospholipase A2 activity and gut microbiota composition in patients with coronary artery disease

Background: Clinical studies have demonstrated possible beneficial effects of flaxseed on cardiovascular disease risk factors, but limited studies have evaluated the effects of flaxseed on the plasma lipoprotein-associated phospholipase A2 (Lp-PLA2) and gut microbial composition in patients with coronary artery disease (CAD). Aim: The purpose of the present study was to examine the effect of flaxseed consumption on plasma lipids and lipoproteins, Lp-PLA2 activity, as well as the relative abundance of some gut microbiota in CAD patients. Methods: In a randomized controlled parallel trial, 50 patients with CAD were randomly allocated to 12 weeks of supplementation of flaxseed (30 g/day) or control (usual care). Before and after the intervention, plasma lipids, Lp-PLA2 activity, and some gut microbiota composition (4 different bacterial genera, including Lactobacillus, Bifidobacteria, Bacteroidetes, Firmicutes) were measured. Results: Compared to control, flaxseed consumption was associated with improved Lp-PLA2 activity. After 12 weeks of intervention, no significant changes were observed in plasma lipids and fecal microbial composition in the two study groups. Conclusion: The present study showed that in patients with CAD, flaxseed supplementation reduced plasma Lp-PLA2 activity but had no effect on plasma lipids and the composition of some intestinal bacteria.