Serum lipoprotein(a) complexes with beta2-glycoprotein I levels in patients with ischemic stroke

Lipoprotein(a) and stroke: a two-sample Mendelian randomization study

Background

To evaluate the causal relationship between lipoprotein(a) Lp(a) and stroke risk.

Method

Adopting two grand scale genome-wide association study (GWAS) databases, the instrumental variables were selected on the basis that the genetic loci met the criteria of being independent of each other and closely related to Lp(a). Summary-level data for outcomes, ischemic stroke and its subtypes were acquired from the UK Biobank and MEGASTROKE consortium databases. Two-sample MR analyses were achieved using inverse variance-weighted (IVW) meta-analysis (primary analysis), weighted median analysis, and the MR Egger regression method. Multivariable-adjusted Cox regression models were also used for observational analysis.

Result

Genetically predicted Lp(a) was marginally related with higher odds of total stroke (odds ratio (OR) [95% confidence intervals (CI)]: 1.003 [1.001-1.006], p = 0.010), ischemic stroke (OR [95% CI]: 1.004[1.001-1.007], p = 0.004), and large-artery atherosclerotic stroke (OR [95% CI]: 1.012 [1.004-1.019], p = 0.002) when the IVW estimator was used on the MEGASTROKE data. The associations of Lp(a) with stroke and ischemic stroke were also remarkable in the primary analysis using the UK Biobank data. Higher Lp(a) levels were also related with increased total stroke and ischemic stroke risk in the observational research data in the UK Biobank database.

Conclusion

Genetically predicted higher Lp(a) perhaps rise the risk of total stroke, ischemic stroke, and large-artery atherosclerotic stroke.

Exploring the role of lipoprotein(a) in cardiovascular diseases and diabetes in Chinese population

A high level of lipoprotein (a) in the plasma has been associated with a variety of cardiovascular diseases and is considered to be an independent predictor of some other diseases. Based on recent studies, the concentration levels of Lp(a) in the Chinese population exhibit a distinctive variation from other populations. In the Chinese population, a high level of Lp(a) indicates a higher incidence of revascularization, platelet aggregation, and thrombogenicity following PCI. Increased risk of atherosclerotic cardiovascular disease (ASCVD) in Chinese population has been linked to higher levels of Lp(a), according to studies. More specifically, it has been found that in Chinese populations, higher levels of Lp(a) were linked to an increased risk of coronary heart disease, severe aortic valve stenosis, deep vein thrombosis in patients with spinal cord injuries, central vein thrombosis in patients receiving hemodialysis, and stroke. Furthermore, new and consistent data retrieved from several clinical trials also suggest that Lp (a) might also play an essential role in some other conditions, including metabolic syndrome, type 2 diabetes and cancers. This review explores the clinical and epidemiological relationships among Lp(a), cardiovascular diseases and diabetes in the Chinese population as well as potential Lp(a) underlying mechanisms in these diseases. However, further research is needed to better understand the role of Lp(a) in cardiovascular diseases and especially diabetes in the Chinese population.

Lipoprotein(a) and Atherosclerotic Cardiovascular Diseases: Evidence from Chinese Population

Cardiovascular disease (CVD) is the leading cause of mortality worldwide. Multiple factors are involved in CVD, and emerging data indicate that lipoprotein(a) (Lp(a)) may be associated with atherosclerotic cardiovascular disease (ASCVD) independent of other traditional risk factors. Lp(a) has been identified as a novel therapeutic target. Previous studies on the influence of Lp(a) in CVD have mainly used in western populations. In this review, the association of plasma Lp(a) concentration with ASCVD was summarized, with regards to epidemiological, population-based observational, and pathological studies in Chinese populations. Lp(a) mutations and copy number variations in Chinese populations are also explored. Finally, the impact of plasma Lp(a) levels on patients with type 2 diabetes mellitus, cancer, and familial hypercholesterolemia are discussed.

Lipoprotein (a) level as a risk factor for stroke and its subtype: A systematic review and meta-analysis

The role of lipoprotein-A [Lp (a)] as a risk factor for stroke is less well documented than for coronary heart disease. Hence, we conducted a systematic review and meta-analysis for the published observational studies in order to investigate the association of Lp (a) levels with the risk of stroke and its subtypes. In our meta-analysis, 41 studies involving 7874 ischemic stroke (IS) patients and 32,138 controls; 13 studies for the IS subtypes based on TOAST classification and 7 studies with 871 Intracerebral hemorrhage (ICH) cases and 2865 control subjects were included. A significant association between increased levels of Lp (a) and risk of IS as compared to control subjects was observed (standardized mean difference (SMD) 0.76; 95% confidence interval (CIs) 0.53-0.99). Lp (a) levels were also found to be significantly associated with the risk of large artery atherosclerosis (LAA) subtype of IS (SMD 0.68; 95% CI 0.01-1.34) as well as significantly associated with the risk of ICH (SMD 0.65; 95% CI 0.13-1.17) as compared to controls. Increased Lp (a) levels could be considered as a predictive marker for identifying individuals who are at risk of developing IS, LAA and ICH.

Lipoprotein (a) as a risk factor for ischemic stroke: a meta-analysis

OBJECTIVE

Lipoprotein (a) [Lp(a)] harbors atherogenic potential but its role as a risk factor for ischemic stroke remains controversial. We conducted a meta-analysis to determine the relative strength of the association between Lp(a) and ischemic stroke and identify potential subgroup-specific risk differences.

METHODS

A systematic search using the MeSH terms "lipoproteins" OR "lipoprotein a" AND "stroke" was performed in PubMed and ScienceDirect for case-control studies from June 2006 and prospective cohort studies from April 2009 until December 20th 2014. Data from eligible papers published before these dates were reviewed and extracted from previous meta-analyses. Studies that assessed the relationship between Lp(a) levels and ischemic stroke and reported generic data-i.e. odds ratio [OR], hazard ratio, or risk ratio [RR]-were eligible for inclusion. Studies that not distinguish between ischemic and hemorrhagic stroke and transient ischemic attack were excluded. Random effects meta-analyses with mixed-effects meta-regression were performed by pooling adjusted OR or RR.

RESULTS

A total of 20 articles comprising 90,904 subjects and 5029 stroke events were eligible for the meta-analysis. Comparing high with low Lp(a) levels, the pooled estimated OR was 1.41 (95% CI, 1.26-1.57) for case-control studies (n = 11) and the pooled estimated RR was 1.29 (95% CI, 1.06-1.58) for prospective studies (n = 9). Sex-specific differences in RR were inconsistent between case-control and prospective studies. Study populations with a mean age of ≤55 years had an increased RR compared to older study populations. Reported Lp(a) contrast levels and ischemic stroke subtype significantly contributed to the heterogeneity observed in the analyses.

CONCLUSION

Elevated Lp(a) is an independent risk factor for ischemic stroke and may be especially relevant for young stroke patients. Sex-specific risk differences remain conflicting. Further studies in these subgroups may be warranted.