Consistency of extended-release niacin/laropiprant effects on Lp(a), ApoB, non-HDL-C, Apo A1, and ApoB/ApoA1 ratio across patient subgroups

Apolipoprotein B and Cardiovascular Disease: Biomarker and Potential Therapeutic Target

Apolipoprotein (apo) B, the critical structural protein of the atherogenic lipoproteins, has two major isoforms: apoB48 and apoB100. ApoB48 is found in chylomicrons and chylomicron remnants with one apoB48 molecule per chylomicron particle. Similarly, a single apoB100 molecule is contained per particle of very-low-density lipoprotein (VLDL), intermediate density lipoprotein, LDL and lipoprotein(a). This unique one apoB per particle ratio makes plasma apoB concentration a direct measure of the number of circulating atherogenic lipoproteins. ApoB levels indicate the atherogenic particle concentration independent of the particle cholesterol content, which is variable. While LDL, the major cholesterol-carrying serum lipoprotein, is the primary therapeutic target for management and prevention of atherosclerotic cardiovascular disease, there is strong evidence that apoB is a more accurate indicator of cardiovascular risk than either total cholesterol or LDL cholesterol. This review examines multiple aspects of apoB structure and function, with a focus on the controversy over use of apoB as a therapeutic target in clinical practice. Ongoing coronary artery disease residual risk, despite lipid-lowering treatment, has left patients and clinicians with unsatisfactory options for monitoring cardiovascular health. At the present time, the substitution of apoB for LDL-C in cardiovascular disease prevention guidelines has been deemed unjustified, but discussions continue.

The effects of KaiXinSan on depression and its association with lipid profiles: A randomized, double-blinded, placebo-controlled trial

BACKGROUND

Traditional Chinese medicine (TCM) KaiXinSan (KXS) has been used to treat depressed patients for a long time, but its potential underlying mechanisms have not been fully understood.

HYPOTHESIS

KXS could mitigate symptoms of patients with atypical depression at least partly via regulating lipid equilibrium.

METHODS

Patients meeting DSM-IV criteria for mild or moderate depression were assigned into placebo (N = 68) or KXS 3.2 g/day (N = 66) groups in a randomized, double-blinded, placebo-controlled, parallel clinical trial to investigate the anti-depressive efficacy of KXS and its association with serum lipid profile.

RESULTS

The HAMD score and SDS score at 8 weeks were significantly improved in KXS-treated patients the N-BACK accuracy rate was also increased after 8 weeks of KXS treatment compared with baseline. These results indicated that KXS not only improved the specific symptoms of depression, but also had a beneficial effect on cognitive function related working memory. More importantly, KXS treatment improved patients' lipid profile by reducing the ratios of LDL/HDL and ApoB/ApoA1 (p < 0.05), as well as ApoC3 level. Moreover, subgroup analysis found that HAMD score was significantly higher in patients with high lipid profile than in those with normal lipid profile, and lipid improvement after 8 weeks of KXS treatment was more obvious in depressed patients with high lipid profile than with normal lipid profile.

CONCLUSION

KXS could mitigate symptoms of patients with minor and modest depression at least partly via regulating lipid equilibrium. Its might shed light that KXS may likely contributes to depressed patients with other cardio-metabolic diseases.

Expression and influence of pentraxin-3, HbAlc and ApoA1/ApoB in serum of patients with acute myocardial infarction combined with diabetes mellitus type 2

The present study investigated the clinical significance of changes in levels of hypersensitive plasma pentraxin-3 (PTX3), hemoglobin A1c (HbAlc) and apolipoprotein A-I (ApoA1)/apolipoprotein B (ApoB) on patients with acute myocardial infarction (AMI) and diabetes mellitus type 2 (T2DM). After admission, 100 patients diagnosed with AMI combined with T2DM were selected as Group A. According to the level of fasting blood glucose (FBG), they were then subdivided into Group A1 (n=44) with FBG ≥13.0 mmol/l and Group A2 (n=56) with FBG <13.0 mmol/l. A total of 100 hospitalized patients with AMI in People's Hospital of Dongying (Dongying, China) were collected as Group B, and 100 healthy people receiving physical examination in the Physical Examination Center of People's Hospital of Dongying were selected as Group C. Serum PTX3, HbAlc and ApoA1/ApoB of all the study participants were tested, and diseased coronary artery vessels were divided into single-, double- and triple-vessel lesions according to their numbers. Logistic regression analysis was performed for the number of diseased coronary artery vessels and each index. The level of PTX3 in Group A1 was higher than that in Group A2; the level of ApoA1/ApoB in the former was lower than that in the latter (P<0.05); and the level of HbAlc in the former was significantly higher than that in the latter (P<0.01); the levels of PTX3 and HbA1c in Group A2 were higher than those in Group B, while the level of ApoA1/ApoB in the former was lower than that in the latter (P<0.05). Logistic regression analysis showed that the number of diseased coronary artery vessels was positively correlated with PTX3 and HbA1c, but negatively correlated with ApoA1/ApoB. PTX3, HbAlc and ApoA1/apoB have a certain clinical significance in assessing the severity of AMI combined with T2DM.

Niacin

Nicotinic acid and nicotinamide, collectively referred to as niacin, are nutritional precursors of the bioactive molecules nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). NAD and NADP are important cofactors for most cellular redox reactions, and as such are essential to maintain cellular metabolism and respiration. NAD also serves as a cosubstrate for a large number of ADP-ribosylation enzymes with varied functions. Among the NAD-consuming enzymes identified to date are important genetic and epigenetic regulators, e.g., poly(ADP-ribose)polymerases and sirtuins. There is rapidly growing knowledge of the close connection between dietary niacin intake, NAD(P) availability, and the activity of NAD(P)-dependent epigenetic regulator enzymes. It points to an exciting role of dietary niacin intake as a central regulator of physiological processes, e.g., maintenance of genetic stability, and of epigenetic control mechanisms modulating metabolism and aging. Insight into the role of niacin and various NAD-related diseases ranging from cancer, aging, and metabolic diseases to cardiovascular problems has shifted our view of niacin as a vitamin to current views that explore its potential as a therapeutic.

Niacin for primary and secondary prevention of cardiovascular events

BACKGROUND

Nicotinic acid (niacin) is known to decrease LDL-cholesterol, and triglycerides, and increase HDL-cholesterol levels. The evidence of benefits with niacin monotherapy or add-on to statin-based therapy is controversial.

OBJECTIVES

To assess the effectiveness of niacin therapy versus placebo, administered as monotherapy or add-on to statin-based therapy in people with or at risk of cardiovascular disease (CVD) in terms of mortality, CVD events, and side effects.

SEARCH METHODS

Two reviewers independently and in duplicate screened records and potentially eligible full texts identified through electronic searches of CENTRAL, MEDLINE, Embase, Web of Science, two trial registries, and reference lists of relevant articles (latest search in August 2016).

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that either compared niacin monotherapy to placebo/usual care or niacin in combination with other component versus other component alone. We considered RCTs that administered niacin for at least six months, reported a clinical outcome, and included adults with or without established CVD.

DATA COLLECTION AND ANALYSIS

Two reviewers used pre-piloted forms to independently and in duplicate extract trials characteristics, risk of bias items, and outcomes data. Disagreements were resolved by consensus or third party arbitration. We conducted random-effects meta-analyses, sensitivity analyses based on risk of bias and different assumptions for missing data, and used meta-regression analyses to investigate potential relationships between treatment effects and duration of treatment, proportion of participants with established coronary heart disease and proportion of participants receiving background statin therapy. We used GRADE to assess the quality of evidence.

MAIN RESULTS

We included 23 RCTs that were published between 1968 and 2015 and included 39,195 participants in total. The mean age ranged from 33 to 71 years. The median duration of treatment was 11.5 months, and the median dose of niacin was 2 g/day. The proportion of participants with prior myocardial infarction ranged from 0% (4 trials) to 100% (2 trials, median proportion 48%); the proportion of participants taking statin ranged from 0% (4 trials) to 100% (12 trials, median proportion 100%).Using available cases, niacin did not reduce overall mortality (risk ratio (RR) 1.05, 95% confidence interval (CI) 0.97 to 1.12; participants = 35,543; studies = 12; I2 = 0%; high-quality evidence), cardiovascular mortality (RR 1.02, 95% CI 0.93 to 1.12; participants = 32,966; studies = 5; I2 = 0%; moderate-quality evidence), non-cardiovascular mortality (RR 1.12, 95% CI 0.98 to 1.28; participants = 32,966; studies = 5; I2 = 0%; high-quality evidence), the number of fatal or non-fatal myocardial infarctions (RR 0.93, 95% CI 0.87 to 1.00; participants = 34,829; studies = 9; I2 = 0%; moderate-quality evidence), nor the number of fatal or non-fatal strokes (RR 0.95, 95% CI 0.74 to 1.22; participants = 33,661; studies = 7; I2 = 42%; low-quality evidence). Participants randomised to niacin were more likely to discontinue treatment due to side effects than participants randomised to control group (RR 2.17, 95% CI 1.70 to 2.77; participants = 33,539; studies = 17; I2 = 77%; moderate-quality evidence). The results were robust to sensitivity analyses using different assumptions for missing data.

AUTHORS' CONCLUSIONS

Moderate- to high-quality evidence suggests that niacin does not reduce mortality, cardiovascular mortality, non-cardiovascular mortality, the number of fatal or non-fatal myocardial infarctions, nor the number of fatal or non-fatal strokes but is associated with side effects. Benefits from niacin therapy in the prevention of cardiovascular disease events are unlikely.

Safety and Tolerability of CSL112, a Reconstituted, Infusible, Plasma-Derived Apolipoprotein A-I, After Acute Myocardial Infarction: The AEGIS-I Trial (ApoA-I Event Reducing in Ischemic Syndromes I)

BACKGROUND

Human or recombinant apolipoprotein A-I (apoA-I) has been shown to increase high-density lipoprotein-mediated cholesterol efflux capacity and to regress atherosclerotic disease in animal and clinical studies. CSL112 is an infusible, plasma-derived apoA-I that has been studied in normal subjects or those with stable coronary artery disease. This study aimed to characterize the safety, tolerability, pharmacokinetics, and pharmacodynamics of CSL112 in patients with a recent acute myocardial infarction.

METHODS

The AEGIS-I trial (Apo-I Event Reducing in Ischemic Syndromes I) was a multicenter, randomized, double-blind, placebo-controlled, dose-ranging phase 2b trial. Patients with myocardial infarction were stratified by renal function and randomized 1:1:1 to CSL112 (2 g apoA-I per dose) and high-dose CSL112 (6 g apoA-I per dose), or placebo for 4 consecutive weekly infusions. Coprimary safety end points were occurrence of either a hepatic safety event (an increase in alanine transaminase >3 times the upper limit of normal or an increase in total bilirubin >2 times the upper limit of normal) or a renal safety event (an increase in serum creatinine >1.5 times the baseline value or a new requirement for renal replacement therapy).

RESULTS

A total of 1258 patients were randomized, and 91.2% received all 4 infusions. The difference in incidence rates for an increase in alanine transaminase or total bilirubin between both CSL112 arms and placebo was within the protocol-defined noninferiority margin of 4%. Similarly, the difference in incidence rates for an increase in serum creatinine or a new requirement for renal replacement therapy was within the protocol-defined noninferiority margin of 5%. CSL112 was associated with increases in apoA-I and ex vivo cholesterol efflux similar to that achieved in patients with stable coronary artery disease. In regard to the secondary efficacy end point, the risk for the composite of major adverse cardiovascular events among the groups was similar.

CONCLUSIONS

Among patients with acute myocardial infarction, 4 weekly infusions of CSL112 are feasible, well tolerated, and not associated with any significant alterations in liver or kidney function or other safety concern. The ability of CSL112 to acutely enhance cholesterol efflux was confirmed. The potential benefit of CSL112 to reduce major adverse cardiovascular events needs to be assessed in an adequately powered phase 3 trial.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifier: NCT02108262.

Infusion of Reconstituted High-Density Lipoprotein, CSL112, in Patients With Atherosclerosis: Safety and Pharmacokinetic Results From a Phase 2a Randomized Clinical Trial

Background

CSL112 is a new formulation of human apolipoprotein A-I (apoA-I) being developed to reduce cardiovascular events following acute coronary syndrome. This phase 2a, randomized, double-blind, multicenter, dose-ranging trial represents the first clinical investigation to assess the safety and pharmacokinetics/pharmacodynamics of a CSL112 infusion among patients with stable atherosclerotic disease.

Methods and Results

Patients were randomized to single ascending doses of CSL112 (1.7, 3.4, or 6.8 g) or placebo, administered over a 2-hour period. Primary safety assessments consisted of alanine aminotransferase or aspartate aminotransferase elevations >3× upper limits of normal and study drug–related adverse events. Pharmacokinetic/pharmacodynamic assessments included apoA-I plasma concentration and measures of the ability of serum to promote cholesterol efflux from cells ex vivo. Of 45 patients randomized, 7, 12, and 14 received 1.7-, 3.4-, and 6.8-g CSL112, respectively, and 11 received placebo. There were no clinically significant elevations (>3× upper limit of normal) in alanine aminotransferase or aspartate aminotransferase. Adverse events were nonserious and mild and occurred in 5 (71%), 5 (41%), and 6 (43%) patients in the CSL112 1.7-, 3.4-, and 6.8-g groups, respectively, compared with 3 (27%) placebo patients. The imbalance in adverse events was attributable to vessel puncture/infusion-site bruising. CSL112 resulted in rapid (T_max≈2 hours) and dose-dependent increases in apoA-I (145% increase in the 6.8-g group) and total cholesterol efflux (up to 3.1-fold higher than placebo) (P<0.001).

Conclusions

CSL112 infusion was well tolerated in patients with stable atherosclerotic disease. CSL112 immediately raised apoA-I levels and caused a rapid and marked increase in the capacity of serum to efflux cholesterol. This potential novel approach for the treatment of atherosclerosis warrants further investigation.

Clinical Trial Registration

URL: http://www.ClinicalTrials.gov. Unique identifier: NCT01499420.

Effects of phenotypic and genotypic factors on the lipid responses to niacin in Chinese patients with dyslipidemia

The acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes DGAT1 and DGAT2 catalyze the final step in triglycerides biosynthesis. This study examined the relationships of baseline phenotypes and the common polymorphisms in DGAT1 and DGAT2 with the lipid responses to niacin.Lipid responses in Chinese patients with dyslipidemia treated with the extended release (ER) niacin/laropiprant combination 1000/20 mg for 4 weeks and then 2000/40 mg for 8 weeks (n = 121, the primary study) or with ER niacin 1500 mg for at least 4 weeks (n = 68, the replication study) were analyzed according to genotypes of DGAT1 rs7003945 T>C and DGAT2 rs3060 T>C polymorphisms.Treatment with ER niacin improved all lipid parameters in both studies. Absolute and percentage changes in lipids were related to their baseline levels, particularly for low-density lipoprotein cholesterol (LDL-C). The DGAT2 rs3060 T>C polymorphism was associated with lower baseline LDL-C, apoB, high-density lipoprotein cholesterol (HDL-C), and apoAI in patients on statin therapy in the primary study. Subjects with the DGAT2 rs3060 T>C variant had less reduction in LDL-C in the primary study and smaller changes in triglyceride and HDL-C in the replication study but these associations became non-significant after adjusting for baseline lipid values. The DGAT1 rs7003945 T>C polymorphism was not related to lipid baseline values or changes in either study. Concomitant statin therapy and lower body weight were also associated with greater reduction in LDL-C.Baseline lipid levels were the main determinants of lipid responses especially for LDL-C. The DGAT2 rs3060 polymorphism might influence the lipid responses depending on baseline phenotype, but this association did not persist after adjustment for the baseline lipid levels.

Pharmacological interventions in human HDL metabolism

PURPOSE OF REVIEW

This review focuses on the recent developments in the field of drugs that affect HDL metabolism. Additionally, some general (retrospective) thoughts on fighting cardiovascular disease through modulating circulating lipids are discussed.

RECENT FINDINGS

Recently, the large 'Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglycerides: Impact on Global Health Outcomes', 'Treatment of HDL to Reduce the Incidence of Vascular Events' and dal-OUTCOMES studies have challenged the idea that raising HDL cholesterol (HDL-c) decreases cardiovascular disease risk. Concerning the failure of these trials, it may, however, be noted that patients with close to normal HDL-c levels were included. It is shown that anacetrapib and evacetrapib massively increase HDL-c, and both compounds are currently tested in phase-III clinical trials. More specific and stronger activators of liver X receptor and peroxisome proliferator-activated receptor (PPAR) are being developed and tested in a preclinical setting. RVX-208 treatment failed to decrease atheroma volume in coronary artery disease patients. Lecithin:cholesterol acyltransferase replacement therapy showed positive results in a patient with lecithin:cholesterol acyltransferase deficiency.

SUMMARY

Inhibition of cholesteryl ester transfer protein, antagomirs against microRNA-33, ApoA-I mimetics and PPARα or PPARα/δ agonists hold on the basis of the current data most promise. However, it will in our opinion be the key that patients with low HDL-c and increased triglyceride should be treated and not those at generally increased risk only. In the poststatin era, personalized medicine, which is inevitably on the horizon, is likely to be helpful for patients who do not reach the goals for LDL cholesterol and HDL-c according to the guidelines. Furthermore, functions of HDL will hopefully be identified as future pharmacological targets.

Extended-release niacin/laropiprant improves endothelial function in patients after myocardial infarction

Raising high-density lipoprotein cholesterol (HDL-C) is an important strategy for reducing residual cardiovascular risk. In the present study, we sought to assess the effect of extended-release niacin/laropiprant on endothelial function in patients after a myocardial infarction with target low-density lipoprotein cholesterol (LDL-C). In this double-blind, placebo-controlled trial, 63 men (35-60 years of age) after a myocardial infarction were randomized to either niacin/laropiprant (1000/20 mg daily for 4 weeks and 2000/40 mg daily thereafter) or placebo. Flow-mediated dilation (FMD) and nitroglycerin-induced (GTN) dilation of the brachial artery, total cholesterol (TC), LDL-C, HDL-C, triglycerides (TG), lipoprotein(a) [Lp(a)], and apolipoprotein (Apo) A1/B were measured at baseline and after 12 weeks of intervention. FMD significantly increased (from 3.9 ± 5.1 to 9.8 ± 4.4%, p < 0.001) in the niacin/laropiprant group, but not in the placebo group (4.6 ± 4.4 to 6.1 ± 4.4%, p = 0.16) (p = 0.02 for comparison of interventions). GTN dilation also increased in the niacin/laropiprant group (from 12.5 ± 6.1 to 16.7 ± 4.8%, p = 0.02), but not in the placebo group (13.4 ± 5.0 to 15.1 ± 5.2%, p = 0.18), (p = 0.60 for comparison of interventions). Niacin/laropiprant reduced TC and LDL-C (p = 0.05 for both) and increased HDL-C (p < 0.001) without influencing TG, with no changes in the placebo group. Lp(a) (p = 0.026) and ApoB (p = 0.014) were significantly lower in the niacin/laropiprant group, with no difference in the placebo group. ApoA1 did not change in either of the groups (p = 0.13; p = 0.26). FMD and GTN dilation improvements did not correlate with changes in the lipid profile. Niacin/laropiprant improves endothelium-dependent and endothelium-independent dilation of the brachial artery. This improvement does not correlate with changes in lipid parameters.

Targeting high density lipoproteins in the prevention of cardiovascular disease?

Recent studies involving HDL-raising therapeutics have greatly changed our understanding of this field. Despite effectively raising HDL-C levels, niacin remains of uncertain clinical benefit. Synthetic niacin receptor agonists are unlikely to raise HDL-C or have other beneficial effects on plasma lipids. Despite the failure in phase 3 of 2 CETP inhibitors, 2 potent CETP inhibitors that raise HDL-C levels by >100 % (and reduce LDL-C substantially) are in late stage clinical development. Infusions of recombinant HDL containing 'wild-type' apoA-I or apoA-I Milano, as well as autologous delipidated HDL, all demonstrated promising early results, and remain in clinical development. A small molecule that causes upregulation of endogenous apoA-I production is also in clinical development. Finally, upregulation of macrophage cholesterol efflux pathways through agonism of liver X receptors or antagonism of miR-33 remains of substantial interest. The field of HDL therapeutics is poised to transition from the 'HDL-cholesterol hypothesis' to the 'HDL flux hypothesis' in which the impact on flux from macrophage to feces is deemed to be of greater therapeutic benefit than the increase in steady-state concentrations of HDL cholesterol.

Pharmacologic interactions of multidrug therapy for dyslipidemia

Despite the best available medical therapy inclusive of statins, substantial residual risk remains for atherothrombotic cardiovascular disease. Non-statin lipid-lowering therapy may help address this critical unmet need through reduction of the levels of low-density lipoprotein and other atherogenic lipoproteins. In the past few years, several landmark trials have provided important information regarding the efficacy and safety of non-statin therapy for dyslipidemia and cardiovascular risk reduction.