Association of kidney function with serum lipoprotein(a) level: the third National Health and Nutrition Examination Survey (1991-1994)

Causal effect of lipoprotein(a) level on chronic kidney disease of European ancestry: a two-sample Mendelian randomization study

INTRODUCTION

Chronic kidney disease is a growing health issue, and the options of prevention and therapy remain limited. Although a number of observational studies have linked higher Lp(a) [lipoprotein(a)] levels to the kidney impairment, the causal relationship remains to be determined. The purpose of this study was to assess the causal association between Lp(a) levels and CKD.

METHODS

We selected eight single-nucleotide polymorphisms (SNPs) significantly associated with Lp(a) levels as instrumental variables. Genome-wide association study (GWAS) from CKDGen consortium yielded the summary data information for CKD. We designed the bidirectional two-sample Mendelian randomization (MR) analyses. The estimates were computed using inverse-variance weighted (IVW), simple median, weighted median, and maximum likelihood. MR-Egger regression was used to detect pleiotropy.

RESULTS

Fixed-effect IVW analysis indicated that genetically predicted Lp(a) levels were associated with CKD significantly (odds ratio, 1.039; 95% CI, 1.009-1.069; p = 0.010). The SNPs showed no pleiotropy according to result of MR-Egger test. Results from sensitivity analyses were consistent. In the inverse MR analysis, random-effect IVW method showed CKD had no causal effect on the elevated Lp(a) (odds ratio, 1.154; 95% CI, 0.845-1.576; p = 0.367).

CONCLUSION

In this bidirectional two-sample MR analysis, the causal deteriorating effects of genetically predicted plasma Lp(a) levels on the risk of CKD were identified. On the contrary, there is no evidence to support a causal effect of CKD on Lp(a) levels.

Association between lipoprotein(a) plasma levels and diabetic nephropathy in Han Chinese patients with type 2 diabetes mellitus

The goal of this study was to evaluate the relationship between serum lipoprotein(a) [Lp(a)] levels and diabetic nephropathy (DN) among Han Chinese individuals with type 2 diabetes mellitus (T2DM). This retrospective analysis comprised a consecutive case series of 767 grown-up patients with T2DM (199 among them with DN) hospitalized in the Department of Endocrinology at the The First Affiliated Hospital of Anhui Medical University from February 20220 to February 2021. Clinical data and other laboratory measurements, such as glycated hemoglobin (HbA1c), were extracted from medical records and compared among groups. Clinical characteristics according to Lp(a) quartiles were also studied. Univariate and multivariate regression analysis were used to examine the relationship between serum Lp(a) and DN. Patients with DN had a longer disease duration, higher HbA1c, higher level of Lp(a), and were more likely to have diabetic retinopathy (DR) than those without DN (P < 0.005 for each). With regard to the Lp(a) quartile group, patients with a higher Lp(a) concentration were more likely to have DN and have higher level of HbA1c during the study (P for trend < 0.005 for each). After adjusting for several confounding factors, the development of DN was significantly associated with the serum Lp(a) level (P = 0.026, comparing the 4th vs 1st quartile of Lp(a)) according to multivariate regression analysis. The receiver operating characteristic (ROC) curves for DN development using serum Lp(a) showed that the area under the receiver operating characteristic curves (AUC) was 0.590 (P < 0.001). Findings from this study demonstrated that the DN was independently associated with the serum Lp(a) level in patients with T2DM in this retrospective study.

Renal function alters the association of lipoprotein(a) with cardiovascular outcomes in patients undergoing percutaneous coronary intervention: a prospective cohort study

Background and hypothesis

Lipoprotein(a) [Lp(a)] and renal dysfunction are both independent risk factors for cardiovascular disease. However, it remains unclear whether renal function mediates the association between Lp(a) and cardiovascular outcomes in patients undergoing percutaneous coronary intervention (PCI).

Methods

From a large prospective cohort study, 10 435 eligible patients undergoing PCI from January 2013 to December 2013 were included in our analysis. Patients were stratified into three renal function groups according to their baseline estimated glomerular filtration rate (eGFR) (<60; 60-90; ≥90 ml/min/1.73 m2). The primary endpoint was a composite of all-cause death, nonfatal MI, ischemic stroke, and unplanned revascularization [major adverse cardiac and cerebrovascular events (MACCE)].

Results

Over a median follow-up of 5.1 years, a total of 2144 MACCE events occurred. After multivariable adjustment, either eGFR <60 ml/min/1.73 m2 or elevated Lp(a) conferred a significantly higher MACCE risk. Higher Lp(a) was significantly associated with an increased risk of MACCE in patients with eGFR <60 ml/min/1.73 m2. However, this association was weakened in subjects with only mild renal impairment and diminished in those with normal renal function. A significant interaction for MACCE between renal categories and Lp(a) was observed (P = 0.026). Patients with concomitant Lp(a) ≥30 mg/dl and eGFR <60 ml/min/1.73 m2 experienced worse cardiovascular outcomes compared with those without.

Conclusion

The significant association between Lp(a) and cardiovascular outcomes was mediated by renal function in patients undergoing PCI. Lp(a)-associated risk was more pronounced in patients with worse renal function, suggesting close monitoring and aggressive management are needed in this population.

Confounding Factors Responsible for Elevated Lp(a) Levels in Patients with Coronary Artery Disease

BACKGROUND

Cardiovascular diseases (CVDs) are a leading cause of global mortality, motivating research into novel approaches for their management. Lipoprotein(a) (Lp(a)), a unique lipoprotein particle, has been implicated in atherosclerosis and thrombosis, suggesting its potential as a therapeutic target for CVDs.

AIM

This study aimed to investigate the association of Lp(a) levels with various cardiovascular parameters and events among patients with confirmed cardiovascular disease.

METHODOLOGY

A prospective study was conducted, enrolling 600 participants, predominantly comprising males (79%), with a mean age of 52.78 ± 0.412 years diagnosed with cardiovascular disease. The follow-up was done for 18 months. Patient demographics, blood investigations, and occurrence of major adverse cardiac events (MACE) were collected. SPSS version 21 was used to statistically analyze the relationships between elevated Lp(a) levels and factors such as age, glycated hemoglobin, mortality, MACE, cardiac death, target vessel revascularization, and stroke.

RESULTS

The study revealed significant (P < 0.05) associations between elevated Lp(a) levels and advanced age, increased glycated hemoglobin levels, as well as occurrences of all-cause mortality, MACE, cardiac death, target vessel revascularization, and stroke. Notably, a significant (P < 0.05), association between high Lp(a) levels and acute coronary syndrome (ACS) emerged, suggesting Lp(a)'s role in advanced cardiac events.

CONCLUSION

The findings highlight the potential significance of Lp(a) as a notable risk factor in cardiovascular health. The observed associations between elevated Lp(a) and adverse cardiovascular events, including ACS, underscore its pathogenic role. Consequently, this study supports the rationale for further research into Lp(a)-specific therapeutic interventions, offering substantial promise in refining the management strategies for cardiovascular diseases.

Association between serum lipoprotein(a) and mildly reduced eGFR: a cross-sectional study

Lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular disease (CVD) and aortic stenosis. However, the data on the relationship between Lp(a) and mildly reduced estimated glomerular filtration rate (eGFR) has been disputed. This study was conducted to assess the relationship between Lp(a) concentrations and mildly reduced eGFR in healthy subjects.This community-based, cross-sectional study enrolled 1,064 volunteers aged ≥ 40 years who lived in Yonghong Community, Zhonglou District, Changzhou, China, between December 2016 and December 2017. A mildly reduced eGFR was defined as eGFR between 60 and 90 mL/min/1.73m2. A standardized questionnaire and biochemical measurements were used to gather information about participants. The serum concentration of Lp(a) was determined using the latex-enhanced immunoturbidimetric test. Of the total study population, 34.8% (n = 370) were men, and the mean age was 66.8 ± 8.5 years. A significant association existed between Lp(a) levels and the risk of mildly reduced eGFR. Individuals with the highest tertile of Lp(a) had higher odds of mildly reduced eGFR after adjusting for various confounders (adjusted odds ratio [OR]: 1.80, 95% confidence interval [CI]: 1.24-2.60, P = 0.0025) compared to those with the lowest tertile of Lp(a). Multivariable logistic regression of studies in which Lp(a) was presented as continuous variables showed consistent results (adjusted OR: 1.23 for 1-SD increment of Ln-Lp(a), 95% CI: 1.05-1.43). Subgroup analyses showed that study characteristics such as age, sex, obesity, diabetes, and hypertension status did not significantly affect the association (P for all interactions > 0.05). These results suggest that higher serum Lp(a) level was an independent risk factor for mildly reduced eGFR.

Trans-ethnic Mendelian-randomization study reveals causal relationships between cardiometabolic factors and chronic kidney disease

BACKGROUND

This study was to systematically test whether previously reported risk factors for chronic kidney disease (CKD) are causally related to CKD in European and East Asian ancestries using Mendelian randomization.

METHODS

A total of 45 risk factors with genetic data in European ancestry and 17 risk factors in East Asian participants were identified as exposures from PubMed. We defined the CKD by clinical diagnosis or by estimated glomerular filtration rate of <60 ml/min/1.73 m2. Ultimately, 51 672 CKD cases and 958 102 controls of European ancestry from CKDGen, UK Biobank and HUNT, and 13 093 CKD cases and 238 118 controls of East Asian ancestry from Biobank Japan, China Kadoorie Biobank and Japan-Kidney-Biobank/ToMMo were included.

RESULTS

Eight risk factors showed reliable evidence of causal effects on CKD in Europeans, including genetically predicted body mass index (BMI), hypertension, systolic blood pressure, high-density lipoprotein cholesterol, apolipoprotein A-I, lipoprotein(a), type 2 diabetes (T2D) and nephrolithiasis. In East Asians, BMI, T2D and nephrolithiasis showed evidence of causality on CKD. In two independent replication analyses, we observed that increased hypertension risk showed reliable evidence of a causal effect on increasing CKD risk in Europeans but in contrast showed a null effect in East Asians. Although liability to T2D showed consistent effects on CKD, the effects of glycaemic phenotypes on CKD were weak. Non-linear Mendelian randomization indicated a threshold relationship between genetically predicted BMI and CKD, with increased risk at BMI of >25 kg/m2.

CONCLUSIONS

Eight cardiometabolic risk factors showed causal effects on CKD in Europeans and three of them showed causality in East Asians, providing insights into the design of future interventions to reduce the burden of CKD.

Serum lipoprotein (a) associates with the risk of renal function damage in the CHCN-BTH Study: Cross-sectional and Mendelian randomization analyses

BACKGROUND

Evidence regarding the effects of lipoprotein (a) [lp(a)] and renal function remains unclear. The present study aimed to explore the causal association of serum lp(a) with renal function damage in Chinese general adults.

METHODS

A total of 25343 individuals with available lp(a) data were selected from the baseline survey of the Cohort Study on Chronic Disease of Communities Natural Population in Beijing, Tianjin, and Hebei (CHCN-BTH). Five renal function indexes [estimated glomerular filtration rate (eGFR), serum creatinine (Scr), blood urea nitrogen (BUN), uric acid (UA), high-sensitivity C-reactive protein(CRPHS)] were analyzed. The restricted cubic spline (RCS) method, logistic regression, and linear regression were used to test the dose-response association between lp(a) and renal function. Stratified analyses related to demographic characteristics and disease status were performed. Two-sample Mendelian randomization (MR) analysis was used to obtain the causal association of lp(a) and renal function indexes. Genotyping was accomplished by MassARRAY System.

RESULTS

Lp(a) levels were independently associated with four renal function indexes (eGFR, Scr, BUN, CRPHS). Individuals with a higher lp(a) level had a lower eGFR level, and the association with Scr estimated GFR was stronger in individuals with a lower lp(a) level (under 14 mg/dL). . The association was similar in individuals regardless of diabetes or hypertension. MR analysis confirmed the causal association of two renal function indexes (Scr and BUN). For MR analysis, each one unit higher lp(a) was associated with 7.4% higher Scr (P=0.031) in the inverse-variance weighted method. But a causal effect of genetically increased lp(a) level with increased eGFR level which contrasted with our observational results was observed.

CONCLUSION

The observational and causal effect of lp(a) on Scr and BUN were founded, suggesting the role of lp(a) on the risk of renal function damage in general Chinese adults.

Association of Lipoprotein(a)-Associated Mortality and the Estimated Glomerular Filtration Rate Level in Patients Undergoing Coronary Angiography: A 51,500 Cohort Study

Background: High lipoprotein(a) is associated with poor prognosis in patients at high risk for cardiovascular disease. Renal function based on the estimated glomerular filtration rate (eGFR) is a potential risk factor for the change of lipoprotein(a). However, the regulatory effect of eGFR stratification on lipoprotein(a)-associated mortality has not been adequately addressed.

Methods: 51,500 patients who underwent coronary angiography (CAG) or percutaneous coronary intervention (PCI) were included from the Cardiorenal ImprovemeNt (CIN) study (ClinicalTrials.gov NCT04407936). These patients were grouped according to lipoprotein(a) quartiles (Q1–Q4) stratified by eGFR categories (<60 and ≥60 mL/min/1.73m²). Cox regression models were used to estimate hazard ratios (HR) for mortality across combined eGFR and lipoprotein(a) categories.

Results: The mean age of the study population was 62.3 ± 10.6 years, 31.3% were female (n = 16,112). During a median follow-up of 5.0 years (interquartile range: 3.0–7.6 years), 13.0% (n = 6,695) of patients died. Compared with lipoprotein(a) Q1, lipoprotein(a) Q2–Q4 was associated with 10% increased adjusted risk of death in all patients (HR: 1.10 [95% CI: 1.03–1.17]), and was strongly associated with about 23% increased adjusted risk of death in patients with eGFR <60 mL/min/1.73m² (HR: 1.23 [95% CI: 1.08–1.39]), while such association was not significant in patients with eGFR ≥60 mL/min/1.73m² (HR: 1.05 [95% CI: 0.97–1.13]). P for interaction between lipoprotein(a) (Q1 vs. Q2–Q4) and eGFR (≥60 vs. eGFR <60 mL/min/1.73m²) on all-cause mortality was 0.019.

Conclusions: Elevated lipoprotein(a) was associated with increased risk of all-cause mortality and such an association was modified by the baseline eGFR in CAG patients. More attention should be paid to the patients with reduced eGFR and elevated lipoprotein(a), and the appropriate lipoprotein(a) intervention is required.

Genetics of Lipoprotein(a): Cardiovascular Disease and Future Therapy

PURPOSE OF REVIEW

Lipoprotein(a) levels are determined 80-90% by genetics and differ by up to 1000-fold between individuals. This review discusses the most recent literature on lipoprotein(a) as a risk factor for cardiovascular disease, as well as future lipoprotein(a)lowering therapies.

RECENT FINDINGS

Over the past few decades, numerous studies have observed that high lipoprotein(a) levels are associated observationally and causally through human genetics with increased risk of cardiovascular disease. Also, the development of safe and effective therapies to lower lipoprotein(a) is ongoing, most importantly using antisense oligonucleotides to prevent production of lipoprotein(a). Finally, both observational and genetic studies have estimated the extent to which lowering of lipoprotein(a) is needed to obtain a clinically meaningful reduction in the risk of cardiovascular disease. Lipoprotein(a) is a causal risk factor for cardiovascular disease; however, currently no approved safe and effective therapy is available to lower lipoprotein(a) levels. That said, promising randomized studies using antisense oligonucleotides show up to 80% reductions in lipoprotein(a), reductions that hopefully will result in lowering the risk of cardiovascular disease as presently tested in the ongoing HORIZON phase 3 trial.

Association Between Lipoprotein (A) and Diabetic Nephropathy in Patients With Type 2 Diabetes Mellitus: A Meta-Analysis

BACKGROUND

Lipoprotein (a) [Lp (a)] has been well recognized as a risk factor of cardiovascular disease. However, the association between serum Lp (a) and diabetic nephropathy in patients with type 2 diabetes mellitus (T2DM) remains unknown. We performed a meta-analysis to comprehensively evaluate the above association.

METHODS

Observational studies aiming to evaluate the independent association between serum Lp (a) and diabetic nephropathy in T2DM patients were identified by systematic search of PubMed and Embase databases. A random-effect model which incorporated the potential intra-study heterogeneity was used for the meta-analysis.

RESULTS

Eleven observational studies with 9304 T2DM patients were included. Results showed that compared to those with the lowest Lp (a), patients with the highest Lp (a) level had higher odds of diabetic nephropathy (adjusted odds ratio [OR]: 1.63, 95% confidence interval [CI]: 1.25-2.14, I² = 54%, P < 0.001). Meta-analysis of studies in which Lp (a) was presented as continuous variables showed consistent result (adjusted OR: 1.13 for 1 mg/dl increment of Lp (a), 95% CI: 1.03-1.24, I2 = 36%, P = 0.008). Subgroup analyses showed that study characteristics such as definitions of diabetic nephropathy and study design did not significantly affect the association (P for subgroup difference all > 0.05).

CONCLUSIONS

Higher serum Lp (a) in patients with T2DM is independently associated with higher odds of diabetic nephropathy. Large scale prospective cohort studies are needed to validate this finding. Moreover, the potential influence of Lp (a) lowering on renal function in T2DM patients may be further investigated.

Lipoprotein(a) levels and association with myocardial infarction and stroke in a nationally representative cross-sectional US cohort

BACKGROUND

Lipoprotein(a) (Lp(a)) has not been well-studied in a nationally representative US cohort.

OBJECTIVE

The objective of this study was to investigate the distribution of Lp(a) and its associations with nonfatal cardiovascular events in a nationally representative cohort.

METHODS

Cross-sectional analysis using the National Health and Nutrition Examination Survey III cohort (1991-1994). We compared Lp(a) levels across demographics and tested the associations between Lp(a) and patient-reported nonfatal myocardial infarction (MI) and/or stroke using multivariate logistic regression.

RESULTS

Median Lp(a) was 14 mg/dL (interquartile range [IQR]: 3, 32) (n = 8214). 14.7% (95% CI: 13.6%-15.9%) had Lp(a) ≥50 mg/dL. Women had slightly higher median Lp(a) than men (14 mg/dL [IQR: 4, 33] vs 13 [(IQR: 3, 30], P = .001). Non-Hispanics blacks had the highest median Lp(a) (35 mg/dL [IQR: 21, 64]), followed by non-Hispanic whites (12 mg/dL [IQR: 3, 29]) and Mexican Americans (8 mg/dL [IQR:1, 21]). In multivariate analysis, Lp(a) was associated (odds ratio per SD increase [95% CI], P-value) with MI (1.41 [1.14-1.75], P = .001), but not stroke (1.14 [0.91-1.44], P = .26). Lp(a) associated with MI in men (1.52 [1.13-2.04], P = .006), non-Hispanic whites (1.60 [1.27-2.03], P < .001), and Mexican Americans (2.14 [1.29-3.55], P = .003), but not women or non-Hispanic blacks. Lp(a) was not associated with stroke among any subgroups.

CONCLUSION

In a nationally representative US cohort, 1 in 7 had Lp(a) ≥50 mg/dL, the guidelines-recommended threshold to consider Lp(a) a risk enhancing factor. Lp(a) was associated with nonfatal MI but not stroke, although there were differential associations by sex and race/ethnicity. Future nationally representative cohorts should test Lp(a) to get an updated estimation.

The role of lipoprotein (a) in chronic kidney disease

Lipoprotein (a) [Lp(a)] and its measurement, structure and function, the impact of ethnicity and environmental factors, epidemiological and genetic associations with vascular disease, and new prospects in drug development have been extensively examined throughout this Thematic Review Series on Lp(a). Studies suggest that the kidney has a role in Lp(a) catabolism, and that Lp(a) levels are increased in association with kidney disease only for people with large apo(a) isoforms. By contrast, in those patients with large protein losses, as in the nephrotic syndrome and continuous ambulatory peritoneal dialysis, Lp(a) is increased irrespective of apo(a) isoform size. Such acquired abnormalities can be reversed by kidney transplantation or remission of nephrosis. In this Thematic Review, we focus on the relationship between Lp(a), chronic kidney disease, and risk of cardiovascular events.

Management of cardiovascular risk factors in patients with ANCA-associated vasculitis

OBJECTIVES

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is accompanied by increased cardiovascular (CV) risk. Treatment of AAV patients includes the management of conventional CV risk factors, primarily hypertension and hypercholesterolemia, while lipoprotein(a) (LP(a)) is an emerging potential target.

METHODS

We performed a multicenter, retrospective study in Germany. Patients were considered if they were between 18 and 90 years old and presented with AAV. Patients with arterial hypertension but no autoimmune disease were used as a control group (HTN reference group).

RESULTS

Compared to the reference group (n = 52), CV disease burden was significantly greater in patients with AAV (n = 53). Hypercholesterolemia was also more common in the AAV patients (71.7% vs 46.2% for the HTN; P = .008). Lipoprotein(a) levels were elevated in both groups, with 11.3% and 17.3% of the AAV and HTN groups, respectively, displaying a level above 0.6 g/l (P = .083). Guideline-recommended targets for low-density lipoprotein cholesterol and blood pressure levels were rarely met. According to Kidney Disease: Improving Global Outcomes guidelines, 72.5% of the patients with AAV should have been taking statins and/or ezetimibe for treatment of hyperlipidemia; however, only 24.3% of them were receiving such treatment. Blood pressure below ≤140/90 mmHg was reached in 78.6% of the patients with chronic kidney disease. However, for patients with chronic kidney disease and an albumin excretion rate of >30 mg/day, the recommended blood pressure is ≤130/80 mmHg, a value that was not reached in 65% of the AAV patients.

CONCLUSION

Patients with AAV are at high CV risk, but management of the associated risk factors is poor. In addition to improving the treatment of hypercholesterolemia and hypertension, lipoprotein(a) is a further potential target for reducing CV risk in individuals with AAV.

Plasma lipoprotein(a) predicts major cardiovascular events in patients with chronic kidney disease who undergo percutaneous coronary intervention

BACKGROUND

Chronic kidney disease (CKD) is associated with increased risk for cardiovascular disease. The predictive power of traditional risk factors for cardiovascular disease is diminished in patients with CKD. The serum level of lipoprotein(a) [Lp(a)] can be a risk factor for adverse events, but the clinical implications of Lp(a) in patients with CKD who have been treated by percutaneous coronary intervention (PCI) remain uncertain. We aimed to determine the role of Lp(a) on long-term outcomes in patients with CKD after PCI.

METHODS

We analyzed data from 904 patients with CKD among 3508 patients who underwent a first PCI between 1997 and 2011 at our institution. We divided patients into 2 groups [high (n=454) or low (n=450)] according to median levels of Lp(a). The primary outcome was a composite of all-cause death and acute coronary syndrome (ACS).

RESULTS

The baseline characteristics of the groups were similar and the median follow-up period was 4.7 years. Cumulative event-free survival was significantly worse for the group with high, than low Lp(a) (P=0.01). Multivariable analysis indicated a high Lp(a) level as an independent predictor of primary outcomes (hazard ratio, 1.35; 95% CI, 1.01-1.82; P=0.04).

CONCLUSIONS

A high Lp(a) value is associated with a poor prognosis after PCI for patients with CKD.

Early renal failure as a cardiovascular disease: Focus on lipoprotein(a) and prothrombotic state

Patients with renal failure are at increased risk of cardiovascular events even at the earliest stages of disease. In addition to many classic cardiovascular risk factors, many conditions that are commonly identified as emerging risk factors might contribute to occurrence of cardiovascular disease. Changes in circulating levels of many of these emerging risk factors have been demonstrated in patients with early stages of renal failure caused by different types of renal disease and have been associated with detection of cardiovascular complications. However, for most of these factors evidence of benefits of correction on cardiovascular outcome is missing. In this article, we comment on the role of lipoprotein(a) and prothrombotic factors as potential contributors to cardiovascular events in patients with early renal failure.

Statins in the management of dyslipidemia associated with chronic kidney disease

The cause of death in the majority of patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) is accelerated cardiovascular disease and not renal failure per se, suggesting a role for statin therapy in this setting. During the past 6 years three large, randomized, placebo-controlled studies of three different statins have been conducted in the dialysis population-but two of these studies did not demonstrate any benefits of statin therapy, and the third study showed only marginally positive results. To understand why statins have failed to reduce cardiovascular events in patients with ESRD, the basic mechanisms underlying the pathogenesis of dyslipidemia in CKD must be critically examined. The observed negative results in the clinical trials of statin therapy might also reflect the biomarkers and targets that were chosen to be evaluated. The characteristics of dyslipidemia in patients with CKD not yet requiring dialysis treatment differ markedly from those of individuals with established ESRD and form the basis for therapeutic recommendations. The potential adverse effects associated with statin therapy are important to consider in the management of dyslipidemia in patients with CKD.

Cardiovascular risk and management in chronic kidney disease

Chronic kidney disease (CKD) is associated with accelerated progression of cardiovascular disease, perhaps because patients with CKD have a high burden of traditional cardiovascular risk factors in addition to a range of nontraditional risk factors such as inflammation and abnormal metabolism of calcium and phosphate. Although the cardiovascular burden of CKD is well documented, potentially beneficial therapies are sometimes underused in patients with stage 3-4 CKD and are rarely studied in patients on dialysis. In this Review, we describe the epidemiology of cardiovascular disease in patients with stage 3-5 CKD (excluding kidney transplant recipients) and outline cardiovascular risk factors that are relevant in this population; we then discuss the implications of this knowledge for the optimal management of cardiovascular risk in this setting. Finally, we highlight opportunities for further research.

Factors associated with lipoprotein(a) in chronic kidney disease

BACKGROUND

It is unclear whether lipoprotein(a) (Lp[a]) levels in patients with chronic kidney disease (CKD) are elevated as a result of reduced glomerular filtration rate (GFR) or other factors associated with CKD. The goal of this study is to describe the association of Lp(a) level with GFR in the context of apoprotein(a) (apo[a]) isoform size, race, and other kidney disease-related factors, such as proteinuria, serum albumin level, C-reactive protein (CRP) level, and serum lipid levels.

METHODS

Lp(a) and apo(a) isoforms were measured in serum samples obtained at baseline from 804 participants in the Modification of Diet in Renal Disease study (GFR range, 13 to 55 mL/min/1.73 m2). The cross-sectional association between Lp(a) level and GFR, apo(a) isoform size, race, and other variables was analyzed in univariate and multivariate linear regression.

RESULTS

Median Lp(a) level was greater in blacks than whites (97.5 versus 28.1 nmol/L; P < 0.001). Those with a low-molecular-weight apo(a) isoform size had greater Lp(a) levels than those with a high-molecular-weight apo(a) isoform size (57.5 versus 21.3 nmol/L; P < 0.001). Lp(a) level was not associated with GFR. Low-molecular-weight apo(a), black race, and greater levels of proteinuria, CRP, and triglycerides were independently associated with greater Lp(a) levels.

CONCLUSION

In this population with CKD stages 3 to 4, GFR was not associated with Lp(a) level, whereas other factors related to CKD, such as proteinuria, CRP level, and triglyceride level, as well as genetic factors such as apo(a) isoform size and race, were associated with Lp(a) level.

Cardiac Disease in Chronic Kidney Disease: Current Understandings and Opportunities for Change

Cardiovascular disease (CVD) is prevalent in patients with kidney disease: in populations prior to dialysis, on dialysis and after transplantation. Publications over the last decade have focused on this, and more recently, patients with cardiac disease are now recognized as being at increased risk in the presence of even mild kidney dysfunction. The presence of both traditional and non-traditional risk factors contributes to this overwhelming burden of cardiovascular disease in patients with chronic kidney disease (CKD). Recent studies have focused on the impact of anemia and disorders of mineral metabolism on CVD outcomes, in the context of inflammation and evidence of cytokine activation. Cross-sectional and prospective observational studies have led to improved understanding, and generated novel hypotheses. To date, no clinical trial has determined the positive impact of interventions targeted at these novel risk factors. This overview describes the current state of knowledge and emphasizes the interplay between CVD and CKD as two aspects of a set of pathophysiological processes, which impact on patient outcomes.

Management of selected lipid abnormalities: hypertriglyceridemia, isolated low HDL-cholesterol, lipoprotein(a), and lipid abnormalities in renal diseases and following solid organ transplantation

Although the focus in treating lipid disorders is on reducing LDL-C levels, additional lipid-related independent risk factors, such as TG, HDL-C, and Lp(a) levels, should be used clinically to assess cardiovascular risk. Decisions to initiate drug therapy for LDL-C reduction may be influenced by levels of these other lipoprotein fractions. Data supporting intervention to modify these factors are less abundant than for LDL-C reduction, but in certain circumstances. drug therapy targeted at TGs or HDL-C may be appropriate. Patients who have nephrotic syndrome and end-stage renal disease are at particularly high risk for the development of CVD and should be treated aggressively for their lipid disorders. Finally, solid organ transplant recipients are almost always hyperlipidemic and appropriate therapy could reduce cardiovascular events.