Lipoprotein (a) and Hypertension

Ancestry specific distribution of LPA Kringle IV-Type-2 genetic variants highlight associations to apo(a) copy number, glucose, and hypertension

Background

High Lp(a) levels contribute to atherosclerotic cardiovascular disease and are tightly regulated by the LPA gene . Lp(a) levels have an inverse correlation with LPA Kringle IV Type-2 (KIV-2) copy number (CN). Black (B) and Hispanic (H) individuals exhibit higher levels of Lp(a), and rates of CVD compared to non-Hispanic Whites (NHW). Therefore, we investigated genetic variations in the LPA KIV-2 region across three ancestries and their associations with metabolic risk factors.

Methods

Using published pipelines, we analyzed a multi-ethnic whole exome dataset comprising 3,817 participants from the Washington Heights and Inwood Columbia Aging Project (WHICAP): 886 [NHW (23%), 1,811 Caribbean (C) H (47%), and 1,120 B individuals (29%). Rare and common variants (alternative allele carrier frequency, CF < 0.01 or > 0.99 and 0.01 < CF < 0.99, respectively) were identified and KIV-2 CN estimated. The associations of variants and CN with history of heart disease, hypertension (HTN), stroke, lipid levels and clinical diagnosis of Alzheimer's disease (AD) was assessed. A small pilot provided in-silico validation of study findings.

Results

We report 1421 variants in the LPA KIV-2 repeat region, comprising 267 exonic and 1154 intronic variants. 61.4% of the exonic variants have not been previously described. Three novel exonic variants significantly increase the risk of HTN across all ethnic groups: 4785-C/A (frequency = 78%, odds ratio [OR] = 1.45, p = 0.032), 727-T/C (frequency = 96%, OR = 2.11, p = 0.032), and 723-A/G (frequency = 96%, OR = 1.97, p = 0.038). Additionally, six intronic variants showed associations with HTN: 166-G/A, 387-G/C, 402-G/A, 4527-A/T, 4541-G/A, and 4653-A/T. One intronic variant, 412-C/T, was associated with decreased blood glucose levels (frequency = 72%, β = -14.52, p = 0.02).Three of the associations were not affected after adjusting for LPA KIV-2 CN: 412-C/T (β = -14.2, p = 0.03), 166-G/A (OR = 1.41, p = 0.05), and 387-G/C (OR = 1.40, p = 0.05). KIV CN itself was significantly associated with 314 variants and was negatively correlated with plasma total cholesterol levels.

Conclusions

In three ancestry groups, we identify novel rare and common LPA KIV-2 region variants. We report new associations of variants with HTN and Glucose levels. These results underscore the genetic complexity of the LPA KIV-2 region in influencing cardiovascular and metabolic health, suggesting potential genetic regulation of pathways that can be studied for research and therapeutic interventions.

Association between lipoprotein(a) and cardiovascular disease in patients undergoing coronary angiography

OBJECTIVE

Many previous studies reported the relationship between lipoprotein(a) and cardiovascular disease, but the conclusions were controversial. The aim of our study was to retrospectively investigate the association between lipoprotein(a) and cardiovascular disease in patients undergoing coronary angiography.

METHODS

We collected and compared clinical information of patients hospitalized for coronary angiography. Multivariable hierarchical logistic regression was used to evaluate the association between lipoprotein(a) and cardiovascular disease in patients undergoing coronary angiography.

RESULTS

There were no significant differences in gender, hypertension, APOA1, smoking, hyperuricemia, obesity, acute myocardial infarction (AMI), cardiac insufficiency, family history of diabetes, or family history of hyperlipidemia among the four groups of lipoprotein(a). Elevated lipoprotein(a) does not increase the risk of hypertriglyceridemia, while elevated lipoprotein(a) increases the risk of high total cholesterol and high low-density lipoprotein cholesterol (LDL-c). Elevated lipoprotein(a) increases the risk of diabetes and premature coronary artery disease (CAD). Elevated lipoprotein(a) increases the incidence of CAD, multivessel lesions, and percutaneous coronary intervention (PCI). Multivariate logistic regression analysis further showed that elevated lipoprotein(a) increases the incidence of high total cholesterol, high LDL‑c, diabetes, CAD, premature CAD, multivessel lesions, and PCI.

CONCLUSION

The findings indicated that elevated lipoprotein(a) had no obvious relationship with hypertension and obesity. Elevated lipoprotein(a) increases the risk of high total cholesterol, high LDL‑c, and premature CAD, and increases the occurrence and severity of coronary heart disease.

Association of lipoprotein(a) with left ventricular hypertrophy assessed by electrocardiogram in adults: a large cross-sectional study

Background and aims

Increasing evidence supports a causal relationship between lipoprotein(a) [Lp(a)] and atherosclerotic cardiovascular disease, yet its association with left ventricular hypertrophy (LVH) assessed by electrocardiogram (ECG) remains unknown. The aim of this study was to explore the relationship between Lp(a) and LVH assessed by ECG in general population.

Methods and results

In this cross-sectional study, we screened 4,052 adults from the participants of the third National Health and Nutrition Examination Survey for analysis. Lp(a) was regarded as an exposure variable. LVH defined by the left ventricular mass index estimated from ECG was considered as an outcome variable. Multivariate logistic regression and restricted cubic spline (RCS) were used to assess the relationship between Lp(a) and LVH. Individuals with LVH had higher Lp(a) compared to individuals without LVH (P< 0.001). In the fully adjusted model, Lp(a) was strongly associated with LVH when as a continuous variable (per 1-unit increment, OR: 1.366, 95% CI: 1.043-1.789, P = 0.024), and higher Lp(a) remained independently associated with a higher risk of LVH when participants were divided into four groups according to quartiles of Lp(a) (Q4 vs Q1, OR: 1.508, 95% CI: 1.185-1.918, P = 0.001). And in subgroup analysis, this association remained significant among participants< 60 years, ≥ 60 years, male, with body mass index< 30 kg/m2, with hypertension and without diabetes (P< 0.05). In addition, we did not observe a nonlinear and threshold effect of Lp(a) with LVH in the RCS analysis (P for nonlinearity = 0.113).

Conclusion

Lp(a) was closely associated with LVH assessed by ECG in general population.

Intracranial Aneurysms and Lipid Metabolism Disorders: From Molecular Mechanisms to Clinical Implications

Many vascular diseases are linked to lipid metabolism disorders, which cause lipid accumulation and peroxidation in the vascular wall. These processes lead to degenerative changes in the vessel, such as phenotypic transformation of smooth muscle cells and dysfunction and apoptosis of endothelial cells. In intracranial aneurysms, the coexistence of lipid plaques is often observed, indicating localized lipid metabolism disorders. These disorders may impair the function of the vascular wall or result from it. We summarize the literature on the relationship between lipid metabolism disorders and intracranial aneurysms below.

Lipoprotein(a) and heart failure: a systematic review

The role of lipoprotein(a) [Lp(a)] as a possible causal risk factor for atherosclerotic artery disease and aortic valve stenosis has been well established. However, the information on the association between Lp(a) levels and heart failure (HF) is limited and controversial. The main objective of the present study was to assess the association between Lp(a) levels and HF. This systematic review was performed according to PRISMA guidelines. A literature search was performed to detect studies that evaluated the association between Lp(a) levels and HF. Eight studies, including 73,410 patients, were eligible for this research. Seven prospective or retrospective cohorts and one cross-sectional study were analyzed. Five studies analyzed populations without HF; another three included patients with HF or left ventricular dysfunction. The endpoints evaluated varied according to the study analyzed, including incident HF, HF hospitalizations, and decreased left ventricular ejection fraction. Lp(a) levels were also analyzed in different ways, including analysis of Lp(a) as a continuous or categorical variable (distinct cut-off points or percentiles). Globally, the studies included in this review found predominantly positive results. Data on some relevant subgroups, such as HF of ischemic or non-ischemic etiology or HF with or without left ventricular dysfunction, was poorly reported. This systematic review suggests that there would be a positive relationship between Lp(a) levels and HF. Given the complexity and heterogeneity of HF, new studies should be developed to clarify this topic.

Lipoprotein(a): Just an Innocent Bystander in Arterial Hypertension?

Elevated plasma lipoprotein(a) [Lp(a)] is a relatively common and highly heritable trait conferring individuals time-dependent risk of developing atherosclerotic cardiovascular disease (CVD). Following its first description, Lp(a) triggered enormous scientific interest in the late 1980s, subsequently dampened in the mid-1990s by controversial findings of some prospective studies. It was only in the last decade that a large body of evidence has provided strong arguments for a causal and independent association between elevated Lp(a) levels and CVD, causing renewed interest in this lipoprotein as an emerging risk factor with a likely contribution to cardiovascular residual risk. Accordingly, the 2022 consensus statement of the European Atherosclerosis Society has suggested inclusion of Lp(a) measurement in global risk estimation. The development of highly effective Lp(a)-lowering drugs (e.g., antisense oligonucleotides and small interfering RNA, both blocking LPA gene expression) which are still under assessment in phase 3 trials, will provide a unique opportunity to reduce "residual cardiovascular risk" in high-risk populations, including patients with arterial hypertension. The current evidence in support of a specific role of Lp(a) in hypertension is somehow controversial and this narrative review aims to overview the general mechanisms relating Lp(a) to blood pressure regulation and hypertension-related cardiovascular and renal damage.

Current Data and New Insights into the Genetic Factors of Atherogenic Dyslipidemia Associated with Metabolic Syndrome

Atherogenic dyslipidemia plays a critical role in the development of metabolic syndrome (MetS), being one of its major components, along with central obesity, insulin resistance, and hypertension. In recent years, the development of molecular genetics techniques and extended analysis at the genome or exome level has led to important progress in the identification of genetic factors (heritability) involved in lipid metabolism disorders associated with MetS. In this review, we have proposed to present the current knowledge related to the genetic etiology of atherogenic dyslipidemia, but also possible challenges for future studies. Data from the literature provided by candidate gene-based association studies or extended studies, such as genome-wide association studies (GWAS) and whole exome sequencing (WES,) have revealed that atherogenic dyslipidemia presents a marked genetic heterogeneity (monogenic or complex, multifactorial). Despite sustained efforts, many of the genetic factors still remain unidentified (missing heritability). In the future, the identification of new genes and the molecular mechanisms by which they intervene in lipid disorders will allow the development of innovative therapies that act on specific targets. In addition, the use of polygenic risk scores (PRS) or specific biomarkers to identify individuals at increased risk of atherogenic dyslipidemia and/or other components of MetS will allow effective preventive measures and personalized therapy.

Association of Lp(a) (Lipoprotein[a]) and Hypertension in Primary Prevention of Cardiovascular Disease: The MESA

BACKGROUND

This study explored the longitudinal relationship of Lp(a) (lipoprotein[a]) and hypertension to cardiovascular outcomes in a large multiethnic cohort free of baseline cardiovascular disease.

METHODS

Individuals from the MESA (Multi-Ethnic Study of Atherosclerosis; N=6674) were grouped as follows: group 1: Lp(a) <50 mg/dL and no hypertension; group 2: Lp(a) ≥50 mg/dL and no hypertension; group 3: Lp(a) <50 mg/dL and hypertension; and group 4: Lp(a) ≥50 mg/dL and hypertension. Kaplan-Meier curves and multivariable Cox proportional hazard models were used to assess the relationship of Lp(a) and hypertension with time to cardiovascular disease events.

RESULTS

Mean follow-up time was 13.9 (5.0) years and 809 participants experienced a cardiovascular disease event. A statistically significant interaction was found between Log[Lp(a)] and hypertension status (P=0.091). Compared with the reference group (Lp[a] <50 mg/dL and no hypertension), those with Lp[a] ≥50 mg/dL and no hypertension had no increased risk for cardiovascular disease events (hazard ratio, 1.09 [95% CI, 0.79-1.50]). However, those with Lp(a) <50 mg/dL and hypertension or Lp(a) ≥50 mg/dL and hypertension demonstrated a statistically significant increase in risk compared to the reference group (hazard ratio, 1.66 [95% CI, 1.39-1.98]) and (hazard ratio, 2.07 [95% CI, 1.63-2.62]), respectively. Among those with hypertension, Lp(a) was associated with a significant increase in cardiovascular disease risk (hazard ratio, 1.24 [95% CI, 1.01-1.53]).

CONCLUSIONS

Although the major contribution to cardiovascular risk was hypertension, elevated Lp(a) significantly modified the association of hypertension with cardiovascular disease. More research is needed to understand mechanistic links among Lp(a), hypertension, and cardiovascular disease.

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.

Cardiac markers: Role in the pathogenesis of arterial hypertension

Cardiac biomarkers may play unique roles in the prognostic evaluation of patients with hypertension, as many cardiac biomarker levels become abnormal long before the onset of obvious cardiovascular disease (CVD). There are numerous cardiac markers. However, this review article only reported the roles of creatinine kinase-MB, cardiac troponins, lipoprotein a, osteopontin, cardiac extracellular matrix, C-reactive protein, cardiac matrix metalloproteinases, cardiac natriuretic peptides, myoglobin, renin, and dynorphin in the pathogenesis of hypertension. This article explained recent major advances, as well as discoveries, significant gaps, and current debates and outlined possible directions for future research. Further studies are required to determine the association between myoglobin and other cardiac markers in hypertension. Moreover, therapeutic approaches are required to determine the early control of these cardiac markers, which ultimately reduce the prevalence of CVDs.

The relationship between lipoprotein(a) and risk of cardiovascular disease: a Mendelian randomization analysis

BACKGROUND

Lipoprotein(a) [Lp(a)] is one of the residual risk factors for cardiovascular disease (CVD) in the setting of optimal low-density lipoprotein cholesterol (LDL-C). The association between Lp(a) and CVD is still in the exploratory phase, with few studies indicating a causal connection between Lp(a) and various CVD.

METHODS

Lp(a) (n = 377,590) was a genome-wide association study (GWAS) based on European populations from Neale Lab. Large GWAS datasets for CVD, including aortic aneurysm(AA) (n = 209,366), atrial fibrillation(AF) (n = 1,030,836), coronary heart disease(CHD) (n = 361,194), secondary hypertension(HBP) (n = 164,147), heart failure(HF) (n = 208,178), ischemic stroke (IS) (n = 218,792), large artery atherosclerosis stroke(ISL) (n = 150, 765), small vessel stroke(ISS) (n = 198,048), lacunar stroke(LIS) (n = 225,419), and pulmonary embolism(PE) (n = 218,413) were also based on European populations. We performed separate univariate two-sample Mendelian randomization (MR) analysis for Lp(a) and CVD as described above. We evaluated this connection mainly using the random-effects inverse variance weighted technique(IVW1) with a 95% confidence interval (CI) for the odds ratio (OR). This was supplemented by MR-Egger, weighted median, maximum likelihood, penalized weighted median, and fixed-effects inverse variance weighted methods. MR-PRESSO offers another means of statistical detection.

RESULTS

Our two-sample MR, which was predominately based on IVW1, revealed a causal relationship between Lp(a) and AA (OR = 1.005, 95%CI: 1.001-1.010, P = 0.009), CHD (OR = 1.003, 95%CI 1.001-1.004, P = 0.010), and ISL (OR = 1.003, 9 5%CI 1.002-1.004, P = 9.50E-11), in addition, there is no causal association with AF, HBP, HF, IS, ISS, LIS, or PE. Similar conclusions were reached by the MR-PRESSO method.

CONCLUSION

This MR study suggested a causal relationship between Lp(a) and CHD, AA, and ISL, but not associated with AF, HF, IS, LIS, ISS, HBP, or PE. Our work further verifies the association between Lp(a) and various CVD, resulting in improved Lp(a) management and a reduction in the prevalence of CVD.

Lipoprotein(a) in systemic lupus erythematosus is associated with history of proteinuria and reduced renal function

OBJECTIVE

Proteinuria is the clinical expression of lupus nephritis and despite recent advances in the therapeutic armamentarium for lupus nephritis, morbidity and mortality rates remain high. Therefore, the identification of factors that predict lupus nephritis is paramount in preventing damage accrual and disease progression. Lipoprotein (a) (Lp[a]) is a primarily genetically inherited plasma lipoprotein with pro-thrombotic and pro-atherosclerotic effects. Elevated Lp(a) has been observed at early stages of renal impairment in the general population and is associated with the development of chronic kidney disease. However, little is known about renal implications of Lp(a) in SLE. Thus, we evaluated Lp(a) and atherosclerotic events, thrombotic events, renal disease, and disease activity in patients with SLE.

METHODS

SLE patients fulfilling the revised American College of Rheumatology (ACR) or SLICC classification criteria with a measurement of Lp(a) were included in the analysis. A cutoff of 125 nmol/L was chosen based on expert opinion. Chi-square test was used to compare the differences between patient characteristics and Lp(a) levels. Logistic regression or linear regression were used, where appropriate, to assess the association between Lp(a) values and the measured outcomes.

RESULTS

Lp(a) levels from 562 patients were analyzed. There was an association between elevated Lp(a) and a history of proteinuria (OR 1.58, p-value = 0.02). This association remained significant following adjustment for age, sex, race, low C3, and elevated anti-dsDNA (OR = 1.55, p-value = 0.04). There was also an association with eGFR < 60 (p = 0.02). Patients with elevated Lp(a) had higher physician global activity (p = 0.01) and erythrocyte sediment rate (p = 0.03).

CONCLUSION

Elevated Lp(a) was associated with proteinuria, independent of known factors associated with lupus proteinuria, as well as reduced eGFR and physician global activity. Our findings highlight the potential role of Lp(a) as a noninvasive biomarker for early renal disease in SLE.