Lipoprotein (a) is a risk factor for coronary artery disease in Chinese Han ethnic population modified by some traditional risk factors: A cross-sectional study of 3462 cases and 6125 controls

Lipoprotein (a) and the Occurrence of Lipid Disorders and Other Cardiovascular Risk Factors in Patients without Diagnosed Cardiovascular Disease

Background: Elevated lipoprotein (a) [Lp(a)] concentrations are linked mainly to genetic factors. The relationship between Lp(a) and other lipid disorders or cardiovascular (CV) risk factors has been less investigated. The aim of this study was to assess the occurrence of lipid disorders and other CV risk factors according to Lp(a) concentrations. Methods: A cross-sectional analysis of 200 primary-care patients who had not been diagnosed with CV disease was conducted. The following risk factors were assessed: older age, history of hypertension, diabetes mellitus or dyslipidemia, smoking, lack of physical activity, body mass index (BMI), and waist circumference. The following lipid parameters were measured: total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), and small, dense LDL (sdLDL-C). Patients were divided into two groups based on their Lp(a) concentrations: <30 mg/dL and ≥30 mg/dL. Results: In 70% of patients, the Lp(a) concentration was <30 mg/dL. The concentrations of lipid parameters did not differ between the groups. The rate of patients with sdLDL-C >1.0 mmol/L was higher in the low-Lp(a) group (10.0 vs. 1.7%, p = 0.04), with no significant differences regarding the other analyzed lipid disorders (p > 0.05). Both in the low- and high-Lp(a) group, most patients had two other abnormal lipid factors (45.0% and 60.0%, respectively). The distribution of impaired lipid parameters (p = 0.41) and other CV risk factors (p = 0.16) was similar in both groups. There was a lower rate of patients >60 years old (15.0% vs. 32.9%, p = 0.01) and with a BMI ≥ 25 kg/m2 (46.7% vs. 63.6%, p = 0.026) in the high-Lp(a) group, and previously diagnosed hyperlipidemia was more prevalent in this group (65.0% vs. 47.1%, p = 0.02). The occurrence of other cardiovascular risk factors did not differ significantly between the Lp(a) groups (p > 0.05). In the high-Lp(a) group, the highest proportion (25.0%) had two CV risk factors, and in the low-Lp(a) group, 31.4% had four CV risk factors. Conclusions: An elevated Lp(a) concentration is not related to the number of conventional CV risk factors or other impairment major lipid parameters.

Association between lipoprotein(a) and insulin resistance in Chinese adults: results from the China health and nutrition survey

Background

Lipoprotein(a) [Lp(a)] is a well-established risk factor for cardiovascular diseases. However, the relationship between Lp(a) and insulin resistance (IR) remains controversial. The aim of the current study was to investigate the association between Lp(a) concentrations and IR in Chinese adults.

Methods

Cross-sectional study of 1908 cases and 5725 controls was performed for identifying the association of Lp(a) with IR. IR was assessed using the triglyceride glucose (TyG) index, and patients with a TyG index greater than the third quartile were defined as having IR.

Results

The distribution of Lp(a) in Chinese adults was skewed, with a median of 7.90mg/dL. Lp(a) concentrations were significantly and progressively lower with increasing TyG index values in Chinese adult males, but not in females. Multiple regression analysis adjusted for a wide range of risk factors showed that Lp(a) concentrations were inversely and independently associated with IR in Chinese adult males, but not in females. The suggested Lp (a) cutoff for discriminating IR from non-IR was 4.7 mg/dL in Chinese adult males. Lp(a) interacts with gender in IR on both additive and multiplicative scale in Chinese adults.

Conclusion

Lp(a) concentrations inversely associated with IR in Chinses adult males, but the association in women needs further study. In Chinese adults, Lp(a) interacts with gender in IR.

Plasma tissue-type plasminogen activator is associated with lipoprotein(a) and clinical outcomes in hospitalized patients with COVID-19

Background

Patients with COVID-19 have a higher risk of thrombosis and thromboembolism, but the underlying mechanism(s) remain to be fully elucidated. In patients with COVID-19, high lipoprotein(a) (Lp(a)) is positively associated with the risk of ischemic heart disease. Lp(a), composed of an apoB-containing particle and apolipoprotein(a) (apo(a)), inhibits the key fibrinolytic enzyme, tissue-type plasminogen activator (tPA). However, whether the higher Lp(a) associates with lower tPA activity, the longitudinal changes of these parameters in hospitalized patients with COVID-19, and their correlation with clinical outcomes are unknown.

Objectives

To assess if Lp(a) associates with lower tPA activity in COVID-19 patients, and how in COVID-19 populations Lp(a) and tPA change post infection.

Methods

Endogenous tPA enzymatic activity, tPA or Lp(a) concentration were measured in plasma from hospitalized patients with and without COVID-19. The association between plasma tPA and adverse clinical outcomes was assessed.

Results

In hospitalized patients with COVID-19, we found lower tPA enzymatic activity and higher plasma Lp(a) than that in non-COVID-19 controls. During hospitalization, Lp(a) increased and tPA activity decreased, which associates with mortality. Among those who survived, Lp(a) decreased and tPA enzymatic activity increased during recovery. In patients with COVID-19, tPA activity is inversely correlated with tPA concentrations, thus, in another larger COVID-19 cohort, we utilized plasma tPA concentration as a surrogate to inversely reflect tPA activity. The tPA concentration was positively associated with death, disease severity, plasma inflammatory, and prothrombotic markers, and with length of hospitalization among those who were discharged.

Conclusion

High Lp(a) concentration provides a possible explanation for low endogenous tPA enzymatic activity, and poor clinical outcomes in patients with COVID-19.

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.

Association of lipoprotein(a) with all-cause and cause-specific mortality: A prospective cohort study

BACKGROUND

A growing number of studies have demonstrated a causal association between lipoprotein(a) [Lp(a)] and atherosclerotic cardiovascular diseases (ASCVDs), but its association with all-cause and cause-specific mortality remains unclear. Therefore, this study aimed to explore the association of Lp(a) with all-cause and cause-specific mortality.

METHODS

This prospective cohort study included 8,525 participants from the third National Health and Nutrition Examination Survey. Lp(a) was considered an exposure variable, all-cause and cause-specific mortality were used as outcome variables, and all participants were followed from the interview date until death or December 31, 2015. COX proportional hazards regression models, stratified analysis, sensitivity analysis, restricted cubic spline plots and Kaplan-Meier survival curves were used to analyze the association of Lp(a) with all-cause and cause-specific mortality.

RESULTS

After adjusting for traditional cardiovascular risk factors, Lp(a) remained strongly associated with all-cause and CVDs-related mortality (P for trend = 0.007 and < 0.001). Subgroup analyses showed that higher Lp(a) remained associated with higher risk of all-cause mortality in those > 60 years of age, with a BMI < 30 kg/m², and without diabetes, whereas the association between Lp(a) and CVDs-related mortality remained stable in participants ≤ 60 years of age, male, with a BMI < 30 kg/m², with hypertension, without diabetes, or without CVDs (P < 0.05). In sensitivity analyses, we found that the association of Lp(a) with all-cause and CVDs-related mortality remained robust after excluding individuals who died within one year of follow-up (P for trend = 0.041 and 0.002).

CONCLUSIONS

Lp(a) was associated with the risk of all-cause and CVDs-related mortality.

Association between Serum Uric Acid and Hypertension in a Large Cross-Section Study in a Chinese Population

Background: The association of serum uric acid (SUA) with hypertension has been well established in Caucasian populations. However, its association with hypertension in Chinese remained to be clarified. Methods: Consecutive patients, homogeneous in Chinese Han ethnicity, aged ≥18 years, abstracted from the database, admitted from 1 January 2010 to 31 December 2013, were included for potential analysis. The patients were grouped according to the presence or absence of hypertension. Unconditional logistic regression was performed to estimate the association between SUA and hypertension. Its possible interactions with risk factors on hypertension were also explored. Results: A total of 9587 patients were finally analyzed in the current study, where 5692 were with hypertension and 3895 were without hypertension. Per 100 μmol/L higher SUA concentration was associated with multivariable-adjusted odds ratios (95% CI) of 1.25 (1.08−1.22) in males, 1.10 (1.01−1.20) in females, and 1.19 (1.13−1.24) in total. On a categorical scale, when compared with the first quintile, the multivariable-adjusted odds ratios (95% CI) were 1.40 (1.20−1.64) for the 2nd quintile, 1.48 (1.27−1.74) for the 3rd quintile, 1.55 (1.32−1.82) for the 4th quintile, and 1.92 (1.63−2.26) for the 5th quintile, with a p for trend < 0.01. Conclusions: SUA is associated with hypertension in a dose-response manner among the Chinese hospitalized population. Management of SUA could help to the prevention and control of hypertension.

The predictive value of CatLet© angiographic scoring system for long-term prognosis in patients with acute myocardial infarction presenting > 12 h after symptom onset

Background

We have recently developed the C oronary A rtery T ree description and L esion E valua T ion (CatLet©) angiographic scoring system, which is capable of accounting for the variability in coronary anatomy, and risk-stratifying patients with coronary artery disease. This study aimed to clarify whether the CatLet score had a predictive value for long-term prognosis in patients with acute myocardial infarction (AMI) presenting > 12 h after symptom onset.

Materials and methods

The CatLet score was calculated for 1,018 consecutively enrolled AMI patients, who were divided into 3 groups according to the CatLet score tertiles. The primary endpoint was major adverse cardiac events (MACEs), defined as a composite of myocardial infarction, cardiac death, and ischemia-driven revascularization; secondary endpoints were all-cause death, cardiac death, myocardial infarction, and ischemia-driven revascularization.

Results

The CatLet score was capable of predicting long-term prognosis at a median 4.9-year follow-up alone or after adjustment for risk factors. Multivariable-adjusted hazard ratios (95% CI)/unit higher score were 1.06 (1.05-1.08) for MACEs, 1.05 (1.03-1.07) for all-cause death, 1.06 (1.04-1.09) for cardiac death, 1.06 (1.04-1.08) for myocardial infarction, and 1.06 (1.04-1.08) for revascularization. The univariate model showed good calibration (χ2 = 8.25, P = 0.4091) and good discrimination (area under ROC curve = 0.7086) for MACEs.

Conclusion

The CatLet score is an independent predictor of long-term clinical outcomes of patients with AMI presenting > 12 h after symptom onset (http://www.chictr.org.cn; Registry Number: ChiCTR2000033730).

A novel deletion mutation in the LPA gene in a middle-aged woman with ischaemic stroke

BACKGROUND

Genetic diversity of the human LPA gene locus is associated with high plasma concentrations of lipoprotein(a) [Lp(a)]. High Lp(a) concentrations are strongly associated with a high incidence rate of ischaemic stroke.

CASE PRESENTATION

A 46-year-old female Chinese patient suffered from ischaemic stroke. Upon admission to the hospital, the patient was diagnosed with an elevated level of plasma Lp(a). The patient's clinical symptoms were alleviated by administration of basilar artery stent thrombectomy, mannitol, and aspirin. A novel compound heterozygous deletion of the region containing exons 3-16 covering kringle IV copy number variation (KIV CNV) domains in the LPA gene was observed in genetic analysis by next-generation sequencing and confirmed by qPCR.

CONCLUSIONS

In the current study, we reported a case of a 46-year-old female patient diagnosed with ischaemic stroke. This novel heterozygous deletion mutation in the LPA gene expands the spectrum of LPA mutations. Further study is required to understand the mechanism of LPA mutations in ischaemic stroke.

Elevated lipoprotein(a) and risk of coronary heart disease according to different lipid profiles in the general Chinese community population: the CHCN-BTH study

Background

To evaluate the contributions of elevated lipoprotein(a) [Lp(a)] to the risk of coronary heart disease (CHD) in the general Chinese community population according to different lipid profiles.

Methods

We recruited individuals aged over 18 years from the baseline survey of the Cohort Study on Chronic Disease of Communities Natural Population in Beijing, Tianjin and Hebei (CHCN-BTH) using a stratified, multistage cluster sampling method. Data were collected through questionnaire surveys, anthropometric measures and laboratory tests. Restricted cubic spline (RCS) functions, multivariate logistic regression, sensitivity analyses and stratified analyses were used to evaluate the association between Lp(a) and CHD.

Results

A total of 25,343 participants were included, with 1,364 (5.38%) identified as having CHD. Elevated Lp(a) levels were linearly related to an increased risk of CHD (P_{overall-association}<0.0001 and P_{nonlinear-association}=0.8468). Multivariate logistic regression analysis indicated that subjects with Lp(a) ≥300 mg/L had a higher risk of CHD [OR (95% CI): 1.36 (1.17, 1.57)] than did individuals with Lp(a) <300 mg/L. Compared with individuals with Lp(a) <119.0 mg/L (<50th percentile), the ORs (95% CI) for CHD in the 51st–80th, 81st–95th and >95th percentiles were 1.07 (0.93, 1.23), 1.26 (1.07, 1.50) and 1.68 (1.30, 2.17), respectively (P for trend <0.0001). This association was also found among the subgroup of subjects without dyslipidemia, including those with normal total cholesterol (TC) (<6.2 mmol/L), triglycerides (TG) (<2.3 mmol/L), high-density lipoprotein cholesterol (HDL-C) (≥1.0 mmol/L) and low-density lipoprotein cholesterol (LDL-C) (<4.1 mmol/L). Elevated Lp(a) and dyslipidemia significantly contributed to a higher risk of CHD with synergistic effects. Stratified analyses showed that elevated Lp(a) concentrations were significantly associated with an increased risk of CHD in the subgroups of individuals who were noncurrent drinkers, overweight individuals, individuals with hypertension, individuals who engaged in moderate physical activity, those without diabetes mellitus and individuals in Beijing and Tianjin.

Conclusions

Elevated Lp(a) concentrations were linearly associated with a higher risk of CHD in the general Chinese community population, especially in normolipidemic subjects. Both dyslipidemia and elevated Lp(a) independently or synergistically contributed to the risk of CHD. Our results suggest that more attention should be paid to the levels of Lp(a) in normolipidemic subjects, which may be an early predictor of CHD.

Interaction between lipoprotein (a) levels and body mass index in first incident acute myocardial infarction

BACKGROUND

Possible interaction between Lipoprotein (a) (Lp(a)) and body mass index (BMI) was investigated with regard to the risk of first incident acute myocardial infarction (AMI).

METHODS

Cross-sectional study of 1522 cases with initial AMI and 1691 controls without coronary artery disease (CAD) were retrospectively analyzed using logistic regression model. Subjects were categorized based on Lp(a) and BMI and compared with regard to occurrence of AMI by calculating odds ratios (ORs) with 95% confidence intervals (CIs). A potential interaction between Lp(a) and BMI was evaluated by the measures of effect modification on both additive (Relative excess risk due to interaction, RERI) and multiplicative scales.

RESULTS

Compared with reference group (BMI < 24 kg/m² and in the first quintile of Lp(a)), multivariable-adjusted analysis revealed that ORs(95%CI) of AMI were 2.27(1.46-3.52) for higher BMI alone; 1.79(1.11-2.90), 1.65(1.05-2.60), 1.96(1.20-3.20) and 2.34(1.47-3.71) for higher Lp(a) alone across its quintiles; and 2.86(1.85-4.40), 3.30(2.14-5.11), 4.43(2.76-7.09) and 5.98(3.72-9.60) for both higher BMI and higher Lp(a), greater than the sum of the both risks each. Prominent interaction was found between Lp(a) and BMI on additive scale (RERI = 2.45 (0.36-4.54) at the fifth quintile of Lp(a)) but not on multiplicative scale.

CONCLUSIONS

This study demonstrates that BMI and Lp(a) levels are important factors affecting the risk of AMI. Significant interaction is found between Lp(a) and BMI in initial AMI on additive scale, indicating that Lp(a) confers greater risk for initial AMI when BMI is elevated. For those whose BMIs are inadequately controlled, Lp(a) lowering may be an option.

TRIAL REGISTRATION

This clinical study was not registered in a publicly available registry because this study was a retrospective study first started in 2015. Data are available via the correspondent.

Association between Serum Calcium and First Incident Acute Myocardial Infarction: A Cross-Sectional Study

Background:

The role of serum calcium in coronary artery disease (CAD) patients with or without first incident acute myocardial infarction has not been studied previously. This study aimed to assess the relationship between serum calcium and first incident acute myocardial infarction.

Methods:

This cross-sectional study was conducted from Jan 2014 to Dec 2016. All the participants were from our database, described in detail elsewhere including 1609 cases and 3252 controls. Multiple logistic regression was carried out to explore the effect of serum calcium on first incident acute myocardial infarction. Interaction between serum calcium and risk factors were evaluated.

Results:

Patients with first incident acute myocardial infarction have significantly lower serum calcium concentrations than those without acute myocardial infarction (2.18 (0.21) vs 2.24 (0.19) mmol/L, P<0.0001). After adjusting for sex and age, logistic regression showed that serum calcium was significantly associated with first incident acute myocardial infarction (odds ratio (OR): 1.50, 95% confidence interval (CI): 1.41–1.60). Further adjusted for potential confounders, serum calcium was associated with first incident acute myocardial infarction (OR: 1.32, 95% CI: 1.22–1.42). Moreover, the association still existed when patients were divided into subgroups according to gender and age. A significant interaction was found between serum calcium and diabetes mellitus (DM), lipoprotein (a) (Lp (a)), and serum albumin.

Conclusion:

Serum calcium was associated with first incident acute myocardial infarction among CAD patients in both sexes and in age categories. This study provides further evidence showing the value of serum calcium levels in clinical practice.

Interaction of lipoprotein(a) with low-density lipoprotein cholesterol on first incident acute myocardial infarction

OBJECTIVE

To evaluate the interaction effects between lipoprotein (a) (Lp(a)) and low-density lipoprotein cholesterol (LDL-C) on first incident acute myocardial infarction (AMI) among Chinese Han population.

METHODS

1522 cases and 1691 controls were retrospectively analyzed. All subjects were grouped by Lp(a) or LDL-C level.

RESULTS

Compared with reference group (LDL-C < 2.6 mmol/L and in the 1st quintile of Lp(a)), multivariable-adjusted analysis revealed that OR(95%CI) of first incident AMI for higher LDL-C alone is 2.66(1.78-3.98); that ORs(95%CI) for higher Lp(a) alone are 1.51(1.07-2.15), 1.84(1.28-2.64), 1.86(1.30-2.67) and 2.66(1.88-3.76) across the Lp(a) quintiles; and that ORs(95%CI) for both higher LDL-C and higher Lp(a) are 3.95(2.64-5.92), 3.20(2.21-4.64), 5.64(3.80-8.36) and 7.48(4.90-11.44) which were greater than the sum of the risks of both alone across the Lp(a) quintiles. Relative excess risks due to interaction were 1.78(95% CI, 0.12-3.44, P = 0.036) and 3.01(0.58-5.44, P = 0.015) at the 4th and 5th quintile of Lp(a), confirming the presence of additive interaction between Lp(a) and LDL-C on initial AMI.

CONCLUSIONS

Lp(a) interacts with LDL-C in first incident AMI on additive scale in Chinese Han population. The risk of initial AMI from exposure of elevated Lp(a) combined with elevated LDL-C is much greater than the sum of the risks from that of both alone.

Association of lipoprotein(a) and major adverse cardiovascular events in patients with percutaneous coronary intervention

INTRODUCTION

The aim of the current study was to evaluate the association between lipoprotein(a) [Lp(a)] and major adverse cardiovascular events (MACEs) in patients with percutaneous coronary intervention (PCI) treatment.

MATERIAL AND METHODS

This was a retrospective study. The demographics, prior medical histories, comorbidities and laboratory parameters were collected from the electronic health record. All participants were followed up for 1 year after the indexed PCI. Studied end points were a composite of MACEs including all-cause mortality, non-fatal myocardial infarction (MI), non-fatal ischemic stroke, transient ischemic attack and stent restenosis.

RESULTS

During 1-year follow-up, 87 MACEs occurred. Compared to patients who did not have MACEs, patients who had MACEs were older, more likely to have higher body mass index, diabetes mellitus and left main lesion, and also had higher baseline low density lipoprotein cholesterol (LDL-C) and Lp(a) levels. All patients in both groups were prescribed aspirin and clopidogrel at discharge. Nearly 97.4% and 95.4% of patients in both groups were treated with statins and a higher proportion of patients in the MACE group were treated with ezetimibe (11.5% vs. 3.5%, p < 0.05). In multivariate regression analysis, diabetes mellitus, LDL-C, Lp(a) and glomerular filtration rate were independent risk factors for MACEs; statin use appeared to be a protective factor for MACEs. Patients with increased Lp(a) level had significantly higher incidence of MACEs than the normal Lp(a) level group (p = 0.001).

CONCLUSIONS

Baseline serum Lp(a) can be used to predict MACEs in patients after PCI treatment, which was independent of LDL-C.

Elevated lipoprotein (a) levels are associated with the acute myocardial infarction in patients with normal low-density lipoprotein cholesterol levels

Elevated lipoprotein (a) [Lp(a)] and coronary artery disease (CAD) risk has been renewed interested in recent years. However, the association between Lp(a) and acute myocardial infarction (AMI) risk in patients with normal low-density lipoprotein cholesterol (LDL-C) levels has yet to been established. A hospital-based observational study including 558 AMI patients and 1959 controls was conducted. Lp(a) level was significantly higher in AMI patients with normal LDL-C levels than that in non-CAD group (median: 134.5 mg/l vs 108 mg/l, P<0.001). According to Lp(a) quartiles (Q1, <51 mg/l; Q2, 51–108 mg/l; Q3, 108–215 mg/l; Q4, ≥215 mg/l), the incidence of AMI increased with the elevated Lp(a) quartiles (P<0.001 and P for trend<0.001). Logistic regression analysis suggested that patients with Q3 and Q4 of Lp(a) values had 1.666 (95%CI = 1.230–2.257, P<0.001) and 1.769 (95%CI = 1.305–2.398, P< 0.001) folds of AMI risk compared with patients with Q1, after adjusting for traditional confounders. Subgroup analyses stratified by gender and age showed that the association only existed in male and late-onset subgroups. In addition, we analyzed the association of Lp(a) with AMI risk in different cut-off values (cut-off 1 = 170 mg/l, cut-off 2 = 300 mg/l). A total of 873 (34.68%) and 432 (17.16%) participants were measured to have higher Lp(a) levels according to cut-off 1 and cut-off 2, respectively. Participants with high Lp(a) levels had 1.418- (cut-off1, 95%CI = 1.150–1.748, P<0.001) and 1.521- (cut-off 2, 95%CI = 1.179–1.963, P< 0.001) folds of AMI risk compared with patients with low Lp(a) levels. The present large-scale study revealed that elevated Lp(a) levels were associated with increased AMI risk in Chinese population with normal LDL-C levels.

Establishing age and sex dependent upper reference limits for the plasma lipoprotein (a) in a Chinese health check-up population and according to its relative risk of primary myocardial infarction

BACKGROUND

Though lipoprotein (a) (Lp (a)) has been considered as a risk factor for coronary artery disease, there is a lack of cutoff values of Lp (a) for Chinese Han ethnicity.

METHODS

We included 1 population for health check-ups. Lp (a) percentile distributions were analyzed and its cutoff for Chinese Han ethnicity was also proposed according to the its relative risk of myocardial infarction.

RESULTS

Lp (a) distributions differed between sexes, and were highly skewed towards low concentrations with a long tail towards the highest ones. The relative risks of elevated Lp (a) concentrations for myocardial infarction had an inflection in Chinese Han ethnic at the 8th decile, corresponding to 167 mg/l, where the risk was prone to be increased. In terms of Lp (a) median concentrations, per higher age quantile (5-y interval) was associated with a significant increase of 3.2 mg/l and females were on average 19.75 mg/l higher than males with a significant difference.

CONCLUSIONS

We proposed Lp (a) < 170 mg/l after rounding as cut-off values for Chinese Han ethnicity. Effects of age and sex on Lp (a) concentrations were also noted. Prospective validation of these cutoff values is critically important in Chinese Han ethnicity.

Low LPA gene kringle IV-2 repeat copy number association with elevated lipoprotein (a) concentration as an independent risk factor of coronary atherosclerotic heart disease in the Chinese Han population

Background

Lipoprotein (a) [Lp(a)], which is genetically determined by the LPA gene kringle IV type 2 (KIV-2) repeat copy number, has previously been reported in different populations. However, it is uncertain if the same occurs in the Chinese Han population. This study explored the correlation of Lp(a) mass or particle concentration with KIV-2 repeat copy number and application for coronary atherosclerotic heart disease (CAHD) risk assessment.

Methods

A cross-sectional study including 884 subjects was conducted. The Lp(a) level and routine risk factors of CAHD were compared. The KIV-2 copy number distribution, relationship with Lp(a), and assessment for CAHD risk were explored.

Results

The mean of Lp(a) mass or particle concentration in the CAHD group was higher than that in the non-CAHD group, while the KIV-2 copy number in the CAHD group was lower. Lp(a) had auxiliary values in gauging the type of plaque and was significantly higher in the soft-plaque group than that in the other two groups (200 mg/L [21.5 nmol/L], 166 mg/L [18.6 nmol/L], 149 mg/L [17.1 nmol/L], respectively, P < 0.05). Kappa test indicated divergence for the same individual using two Lp(a) concentrations (kappa value was 0.536 [< 0.75]). Elevated Lp(a) was an independent CAHD risk factor, whatever mass or particle concentration, and large KIV-2 copy number was a protective factor.

Conclusion

Lp(a) level and small KIV-2 copy number are risk factors for CAHD in the Chinese Han population; furthermore, elevated Lp(a) may gauge the type of coronary plaque.

Lipoprotein(a) level associates with coronary artery disease rather than carotid lesions in patients with familial hypercholesterolemia

BACKGROUND

Lipoprotein(a) [Lp(a)] level is a novel risk factor for atherosclerotic cardiovascular disease in patients with familial hypercholesterolemia (FH), while its impact on the different sites of arteries remains undetermined. We aim to examine the associations of Lp(a) levels with coronary and carotid atherosclerosis in patients with heterozygous FH (HeFH).

METHODS

A total of 148 patients with HeFH who have received carotid ultrasonography and coronary angiography due to chest pain were enrolled. Plasma Lp(a) was measured using immunoturbidimetric method. Finally, the associations between Lp(a) and coronary as well as carotid lesions were evaluated.

RESULTS

Patients with Lp(a) ≥ 300 mg/L had similar carotid intima-media thickness (IMT, 0.782 ± 0.16 mm vs 0.798 ± 0.18 mm, P = .579) and plaque prevalence (66.7% vs 65%, P = .833) compared to those with Lp(a) < 300 mg/L, but had a higher prevalence of coronary artery disease (CAD, 69.7% vs 50.0%, P = .016) and higher Gensini score (GS, median 27 vs 3, P = .006). Moreover, no correlations were found between carotid mean IMT with either Lp(a) level or Lp(a) year score, while positive relation of Lp(a) with GS did. Multivariate regression analysis revealed that Lp(a), Lp(a) year score, and Lp(a) ≥ 300 g/L were all independent predictors for the presence of CAD (OR = 4.99, P = .007; OR = 4.73, P = .009; OR = 4.46, P = .006, respectively) but not for carotid plaques.

CONCLUSIONS

This study suggested that Lp(a) level was associated with the presence and severity of CAD but not with carotid atherosclerosis in patients with HeFH.

LPA kringle IV type 2 is associated with type 2 diabetes in a Chinese population with very high cardiovascular risk

The connection between lipoprotein (a) [Lp(a)] levels and the risks of cardiovascular disease and diabetes remains poorly understood. Lp(a) is encoded by the LPA gene, and evidence suggests that the kringle IV type 2 (KIV-2) variant is particularly important to Lp(a) isoform size. A large isoform size, represented as a high number of KIV-2 repeats in LPA, is associated with low serum Lp(a) concentrations and an increased risk of type 2 diabetes. We investigated the associations among Lp(a) concentrations, LPA KIV-2 repeats, and type 2 diabetes in a Chinese population of 1,863 consecutive patients with very high cardiovascular risk, as identified by coronary angiography. Individuals with Lp(a) levels in the top tertile [67.86 (35.34-318.50) mg/dl] had a lower risk of diabetes compared with those in the bottom tertile [7.38 (0.60-12.91) mg/dl]. There was an inverse association between the number of KIV-2 repeats and serum Lp(a) concentrations. This study demonstrated that a high number of LPA KIV-2 repeats are associated with increased risk of type 2 diabetes in a Chinese population with very high cardiovascular risk, which suggests that large Lp(a) isoform size, associated with low Lp(a) concentration, has a causal effect on type 2 diabetes.

Impact of C-reactive protein on long-term mortality in acute myocardial infarction patients with diabetes and those without

BACKGROUND

Little is known about the relationship between C-reactive protein (CRP) and long-term mortality after acute myocardial infarction (AMI) in diabetic patients. The current study aimed to examine whether CRP levels are associated with for long-term all-cause, cardiovascular, and cardiac mortality in AMI patients with diabetes and those without separately.

METHODS

The cohort study included 663 diabetic and 1853 non-diabetic patients with AMI. The median follow-up time was 1045 days (2.9 years).

RESULTS

According to the median concentration of serum CRP (8.95 mg/l), the patients were divided into two groups. The low CRP level group (<8.95 mg/l) served as a reference. In diabetic patients with AMI, the adjusted hazard ratios (HRs) for long-term all-cause, cardiovascular, and cardiac mortality were 1.62 (P = 0.027), 1.91 (P = 0.008), and 2.08 (P = 0.007), respectively. In non-diabetic patients with AMI, the adjusted hazard ratios (HRs) for long-term all-cause, cardiovascular, and cardiac mortality were 1.72 (P < 0.001), 1.8 (P < 0.001), and 1.78 (P = 0.001), respectively.

CONCLUSIONS

Regardless of whether patients had diabetes or not, CRP value is an independent predictor of long-term, all-cause, cardiovascular, and cardiac mortality after AMI.

A Test in Context: Lipoprotein(a): Diagnosis, Prognosis, Controversies, and Emerging Therapies

Evidence that elevated lipoprotein(a) (Lp[a]) levels contribute to cardiovascular disease (CVD) and calcific aortic valve stenosis (CAVS) is substantial. Development of isoform-independent assays, in concert with genetic, epidemiological, translational, and pathophysiological insights, have established Lp(a) as an independent, genetic, and likely causal risk factor for CVD and CAVS. These observations are consistent across a broad spectrum of patients, risk factors, and concomitant therapies, including patients with low-density lipoprotein cholesterol <70 mg/dl. Statins tend to increase Lp(a) levels, possibly contributing to the "residual risk" noted in outcomes trials and at the bedside. Recently approved proprotein convertase subtilisin/kexin-type 9 inhibitors and mipomersen lower Lp(a) 20% to 30%, and emerging RNA-targeted therapies lower Lp(a) >80%. These approaches will allow testing of the "Lp(a) hypothesis" in clinical trials. This review summarizes the current landscape of Lp(a), discusses controversies, and reviews emerging therapies to reduce plasma Lp(a) levels to decrease risk of CVD and CAVS.

Long-term statin therapy could be efficacious in reducing the lipoprotein (a) levels in patients with coronary artery disease modified by some traditional risk factors

BACKGROUND

Lipoprotein (a) [Lp (a)] is a well-established risk factor for coronary artery disease (CAD). However, up till now, treatment of patients with higher Lp (a) levels is challenging. This current study aimed to investigate the therapeutic effects of short-, medium and long-term statin use on the Lp (a) reduction and its modifying factors.

METHODS

The therapeutic duration was categorized into short-term (median, 39 days), medium term (median, 219 days) and long-term (median, 677 days). The lipid profiles before therapy served as baselines. Patients at short-, medium or long-term exactly matched with those at baseline. Every patient's lipid profiles during the follow-ups were compared to his own ones at baselines.

RESULTS

The current study demonstrated that long-term statin therapy significantly decreased the Lp (a) levels in CAD patients while short-term or medium term statin therapy didn't. When grouped by statin use, only long-term simvastatin use significantly decreased the Lp (a) levels while long-term atorvastatin use insignificantly decreased the Lp (a) levels. Primary hypertension (PH), DM, low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) could modify the therapeutic effects of statin use on the Lp (a) levels in CAD patients.

CONCLUSIONS

The long-term statin therapy could be efficacious in reducing the Lp (a) levels in CAD patients, which has been modified by some traditional risk factors. In the era of commercial unavailability of more reliable Lp (a) lowering drugs, our findings will bolster confidence in fighting higher Lp (a) abnormalities both for patients and for doctors.

Lipoprotein (a) is not significantly associated with type 2 diabetes mellitus: cross-sectional study of 1604 cases and 7983 controls

AIMS

Lipoprotein (a) (Lp(a)), a well-established risk factor for coronary artery diseases (CAD), would also be anticipated to be associated in a similar manner with risk of type 2 diabetes mellitus (T2DM) based on the common soil hypothesis of etiology of T2DM and CAD. Unfortunately, there remains considerable uncertainty regarding the association of Lp(a) with the risk of T2DM. We aimed to examine the association of Lp(a) with T2DM.

METHODS

Cross-sectional study of 1604 cases and 7983 controls was performed for identifying the association of Lp(a) with T2DM, its possible interactions with risk factors and threshold effects on T2DM. The association of Lp(a) with CAD was also examined and compared within the same study.

RESULTS

On a continuous scale, 10 mg/L higher Lp(a) levels were insignificantly associated with a fully adjusted OR of 1.011, 95% CI 0.961-1.063 for T2DM. On a categorical scale, the fully adjusted ORs for T2DM were 0.733 (0.526-1.022), 0.554 (0.387-0.793), 0.848 (0.612-1.176), 0.727 (0.515-1.026), 0.692 (0.488-0.981), 0.696 (0.492-0.985), 0.719 (0.509-1.016), 0.74 (0.523-1.045), 0.809 (0.571-1.146), and 0.99 (0.962-1.019) for decile 2-10 in reference to decile 1. The magnitude of association did not increase with increasing decile (P for trend test = 0.990). In contrast, higher Lp(a) levels were significantly associated with prevalent CAD on a continuous or categorical scale in a fully adjusted model. No threshold effects were observed in terms of association of Lp(a) with T2DM or with CAD in Lp(a) <50 mg/dL.

CONCLUSIONS

The current study suggested that there was a lack of association of Lp(a) levels with prevalent T2DM. In contrast, Lp(a) levels were significantly associated with CAD in a dose-responding manner. Our findings provided evidence for differential approaches to higher Lp(a) levels in patients with T2DM or with CAD.

Risk burdens of modifiable risk factors incorporating lipoprotein (a) and low serum albumin concentrations for first incident acute myocardial infarction

Risk burdens of modifiable risk factors incorporating lipoprotein (a) (Lp(a)) and low serum albumin (LSA) concentrations for first incident acute myocardial infarction (AMI) haven’t been studied previously. Cross-sectional study of 1552 cases and 6125 controls was performed for identifying the association of risk factors with first incident AMI and their corresponding population attributable risks (PARs). Modifiable risk factors incorporating LSA and Lp(a) accounted for up to 92% of PAR for first incident AMI. Effects of these risk factors were different in different sexes across different age categories. Overall, smoking and LSA were the 2 strongest risk factors, together accounting for 64% of PAR for first incident AMI. After multivariable adjustment, Lp(a) and LSA accounted for 19% and 41%, respectively, and together for more than a half (54%) of PAR for first incident AMI. Modifiable risk factors incorporating LSA and Lp(a) have accounted for an overwhelmingly large proportion of the risk of first incident AMI, indicating most first incident AMI is preventable. The knowledge of risk burdens for first incident AMI incorporating Lp (a) and LSA may be beneficial for further reducing first incident AMI from a new angle.