Effect of alirocumab on individuals with type 2 diabetes, high triglycerides, and low high-density lipoprotein cholesterol

Classical and Novel Lipid-Lowering Therapies for Diabetic Patients with Established Coronary Artery Disease or High Risk of Coronary Artery Disease-A Narrative Clinical Review

Diabetic atherosclerosis is a complex process that is characterized by diffuse and unstable lesions increasing 2-4-fold the risk of adverse cardiovascular (CV) events. Diabetic dyslipidemia has a predominant role in coronary artery disease (CAD) and has been the target of classical and emerging pharmaceutical agents with established or promising CV benefits. The aim of the present narrative review was to summarize the effects of classical and novel lipid-lowering pharmaceutical agents on lipid profile and CV outcomes in diabetic patients with established CAD or high risk of CAD. Statins remain the first-line treatment for all diabetic patients since they considerably ameliorate lipid parameters and non-lipid CV risk factors, leading to reduced CV morbidity and mortality. Complementary to statins, ezetimibe exerts lipid-lowering properties with modest but significant reductions in major adverse cardiovascular events (MACEs) and CV mortality. PCSK9 inhibitors considerably reduce LDL-C levels and lower MACEs in diabetic patients. On the other hand, fibrates may confer a very modest decline in MACE incidence, while the CV impact of omega-3 fatty acids is promising but remains questionable. Bempedoic acid and inclisiran have a potential therapeutic role in the management of diabetic dyslipidemia, but this is still not adequately documented. Given the heightened CV risk among individuals with diabetes, more decisive results would be of great importance in the utility of all these drugs.

Targeting NPC1 in Renal Cell Carcinoma

Rapidly proliferating cancer cells have a greater requirement for cholesterol than normal cells. Tumor cells are largely dependent on exogenous lipids given that their growth requirements are not fully met by endogenous pathways. Our current study shows that ccRCC cells have redundant mechanisms of cholesterol acquisition. We demonstrate that all major lipoproteins (i.e., LDL, HDL, and VLDL) have a comparable ability to support the growth of ccRCC cells and are equally effective in counteracting the antitumor activities of TKIs. The intracellular trafficking of exogenous lipoprotein-derived cholesterol appears to be distinct from the movement of endogenously synthesized cholesterol. De novo synthetized cholesterol is transported from the endoplasmic reticulum directly to the plasma membrane and to the acyl-CoA: cholesterol acyltransferase, whereas lipoprotein-derived cholesterol is distributed through the NPC1-dependent endosomal trafficking system. Expression of NPC1 is increased in ccRCC at mRNA and protein levels, and high expression of NPC1 is associated with poor prognosis. Our current findings show that ccRCC cells are particularly sensitive to the inhibition of endolysosomal cholesterol export and underline the therapeutic potential of targeting NPC1 in ccRCC.

Role of lipoprotein(a) in atherosclerotic cardiovascular disease: A review of current and emerging therapies

Lipoprotein(a), or Lp(a), is structurally like low-density lipoprotein (LDL) but differs in that it contains glycoprotein apolipoprotein(a) [apo(a)]. Due to its prothrombotic and proinflammatory properties, Lp(a) is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD) and aortic valve stenosis. Lp(a) levels are genetically determined, and it is estimated that 20%-25% of the global population has an Lp(a) level ≥50 mg/dL (or ≥125 nmol/L). Diet and lifestyle interventions have little to no effect on Lp(a) levels. Lipoprotein apheresis is the only approved treatment for elevated Lp(a) but is time-intensive for the patient and only modestly effective. Pharmacological approaches to reduce Lp(a) levels and its associated risks are of significant interest; however, currently available lipid-lowering therapies have limited effectiveness in reducing Lp(a) levels. Although statins are first-line agents to reduce LDL cholesterol levels, they modestly increase Lp(a) levels and have not been shown to change Lp(a)-mediated ASCVD risk. Alirocumab, evolocumab, and inclisiran reduce Lp(a) levels by 20-25%, yet the clinical implications of this reduction for Lp(a)-mediated ASCVD risk are uncertain. Niacin also lowers Lp(a) levels; however, its effectiveness in mitigating Lp(a)-mediated ASCVD risk remains unclear, and its side effects have limited its utilization. Recommendations for when to screen and how to manage individuals with elevated Lp(a) vary widely between national and international guidelines and scientific statements. Three investigational compounds targeting Lp(a), including small interfering RNA (siRNA) agents (olpasiran, SLN360) and an antisense oligonucleotide (pelacarsen), are in various stages of development. These compounds block the translation of messenger RNA (mRNA) into apo(a), a key structural component of Lp(a), thereby substantially reducing Lp(a) synthesis in the liver. The purpose of this review is to describe current recommendations for screening and managing elevated Lp(a), describe the effects of currently available lipid-lowering therapies on Lp(a) levels, and provide insight into emerging therapies targeting Lp(a).

Advanced progress of the relationship between PCSK9 monoclonal antibodies and hyperglycemic adverse events

Purpose of Review

Long-term use of statins had been confirmed to cause an increase in hyperglycemic adverse events (HAEs), whose mechanism has been well understood. Proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibodies (PCSK9-mAbs), a kind of new lipid-lowering drug, can effectively reduce plasma low-density lipoprotein cholesterol levels in patients with CHD and have been widely used. However, animal experiments, Mendelian randomization studies, clinical researches and Meta-analyses which focused on the relationship between PCSK9-mAbs and HAEs had reached different conclusions, which has attracted great attention from clinicians.

Recent Findings

The newest FOURIER-OLE randomized controlled trial followed PCSK9-mAbs users for over 8 years, whose results suggested that long-term use of PCSK9-mAbs did not increase the incidence of HAEs. Newest Meta-analyses also indicated that there was no relationship between PCSK9-mAbs and NOD. Meanwhile, genetic polymorphisms and variants related to PCSK9 might have effects on HAEs.

Conclusion

According to the results of current studies, there is no significant relationship between PCSK9-mAbs and HAEs. However, longer-term follow-up studies are still needed to confirm it. Although PCSK9 genetic polymorphisms and variants may affect the possible occurrence of HAEs, there is no need to perform relevant genetic testing before applying PCSK9-mAbs.

Morphologies and composition changes in nonculprit subclinical atherosclerosis in diabetic versus nondiabetic patients with acute coronary syndrome who underwent long-term statin therapy

Although patients are undergoing similar lipid-lowering therapy (LLT) with statins, the outcomes of coronary plaque in diabetic mellitus (DM) and non-DM patients are different. Clinical data of 239 patients in this observational study with acute coronary syndrome was from our previous randomized trial were analyzed at 3 years, and 114 of them underwent OCT detection at baseline and the 1-year follow-up were re-anlayzed by a novel artificial intelligence imaging software for nonculprit subclinical atherosclerosis (nCSA). Normalized total atheroma volume changes (ΔTAVn) of nCSA were the primary endpoint. Plaque progression (PP) was defined as any increase in ΔTAVn. DM patients showed more PP in nCSA (ΔTAVn; 7.41 (- 2.82, 11.85) mm³ vs. - 1.12 (- 10.67, 9.15) mm³, p = 0.009) with similar reduction of low-density lipoprotein cholesterol (LDL-C) from baseline to 1-year. The main reason is that the lipid component in nCSA increases in DM patients and non-significantly decreases in non-DM patients, which leads to a significantly higher lipid TAVn (24.26 (15.05, 40.12) mm³ vs. 16.03 (6.98, 26.54) mm³, p = 0.004) in the DM group than in the non-DM group at the 1-year follow-up. DM was an independent predictor of PP in multivariate logistic regression analysis (OR = 2.731, 95% CI 1.160-6.428, p = 0.021). Major adverse cardiac events (MACEs) related to nCSA at 3 years were higher in the DM group than in the non-DM group (9.5% vs. 1.7%, p = 0.027). Despite a comparable reduction in LDL-C levels after LLT, more PP with an increase in the lipid component of nCSA and a higher incidence of MACEs at the 3-year follow-up was observed in DM patients.Trial registration: ClinicalTrials.gov. identifier: NCT02140801.

Feeding-induced hepatokines and crosstalk with multi-organ: A novel therapeutic target for Type 2 diabetes

Hyperglycemia, which can be caused by either an insulin deficit and/or insulin resistance, is the main symptom of Type 2 diabetes, a significant endocrine metabolic illness. Conventional medications, including insulin and oral antidiabetic medicines, can alleviate the signs of diabetes but cannot restore insulin release in a physiologically normal amount. The liver detects and reacts to shifts in the nutritional condition that occur under a wide variety of metabolic situations, making it an essential organ for maintaining energy homeostasis. It also performs a crucial function in glucolipid metabolism through the secretion of hepatokines. Emerging research shows that feeding induces hepatokines release, which regulates glucose and lipid metabolism. Notably, these feeding-induced hepatokines act on multiple organs to regulate glucolipotoxicity and thus influence the development of T2DM. In this review, we focus on describing how feeding-induced cross-talk between hepatokines, including Adropin, Manf, Leap2 and Pcsk9, and metabolic organs (e.g.brain, heart, pancreas, and adipose tissue) affects metabolic disorders, thus revealing a novel approach for both controlling and managing of Type 2 diabetes as a promising medication.

Personalized management of dyslipidemias in patients with diabetes-it is time for a new approach (2022)

Dyslipidemia in patients with type 2 diabetes (DMT2) is one of the worst controlled worldwide, with only about 1/4 of patients being on the low-density lipoprotein cholesterol (LDL-C) target. There are many reasons of this, including physicians' inertia, including diabetologists and cardiologists, therapy nonadherence, but also underusage and underdosing of lipid lowering drugs due to unsuitable cardiovascular (CV) risk stratification. In the last several years there is a big debate on the risk stratification of DMT2 patients, with the strong indications that all patients with diabetes should be at least at high cardiovascular disease (CVD) risk. Moreover, we have finally lipid lowering drugs, that not only allow for the effective reduction of LDL-C and do not increase the risk of new onset diabetes (NOD), and/or glucose impairment; in the opposite, some of them might effectively improve glucose control. One of the most interesting is pitavastatin, which is now available in Europe, with the best metabolic profile within statins (no risk of NOD, improvement of fasting blood glucose, HOMA-IR, HbA1c), bempedoic acid (with the potential for the reduction of NOD risk), innovative therapies-PCSK9 inhibitors and inclisiran with no DMT2 risk increase, and new forthcoming therapies, including apabetalone and obicetrapib-for the latter one with the possibility of even decreasing the number of patients diagnosed with prediabetes and DMT2. Altogether, nowadays we have possibility to individualize lipid lowering therapy in DMT2 patients and increase the number of patients on LDL-C goal without any risk of new onset diabetes and/or diabetes control worsening, and in consequence to reduce the risk of CVD complications due to progression of atherosclerosis in this patients' group.

Impact of Alirocumab on Release Markers of Atherosclerotic Plaque Vulnerability in Patients with Mixed Hyperlipidemia and Vulnerable Atherosclerotic Plaque

Background and Objectives: Atherosclerosis is a disease in the pathogenesis of which plasma factors apart from elevated cholesterol levels play a keyrole. Such factors include osteopontin (OPN), osteoprotegerin (OPG), and metalloproteinases (MMPs), which are factors that may be responsible for the stabilization of atherosclerotic plaque. The aim of this study was to assess the effect of modern lipid-lowering therapy by using proprotein convertase subtilisin/kexin type 9 (PCSK-9) inhibitor on the concentrations of these factors. Materials and Methods: The study included people suffering from dyslipidemia who were eligible to start alirocumab therapy. In this group, the concentrations of OPN, OPG, and MMPs were assessed before the initiation of therapy and after three months of its duration. Results: In the study, we observed a statistically significant reduction in the concentrations of OPN, OPG (p < 0.001), and metalloproteinase 2 (MMP-2) (p < 0.05) after the applied therapy. Moreover, we noticed that in the group of patients soon to start alirocumab therapy, the concentrations of these factors were higher compared to the control group (p < 0.001). Conclusions: The results of our study show that therapy with alirocumab significantly reduces the concentration of factors that affect atherosclerotic plaque vulnerability, which may explain their important role in reducing cardiovascular risk in patients undergoing this therapy.

Relation Between New York Heart Association Functional Class and Remnant Cholesterol, and Non-high Density Lipoprotein Cholesterol in Coronary Heart Disease Patients With Type 2 Diabetes Mellitus

Remnant cholesterol (RC) and non-high-density lipoprotein cholesterol (non-HDL-C) are associated with coronary heart disease (CHD) and type 2 diabetes mellitus (T2DM). However, the association between RC, non-HDL-C, and CHD patients with T2DM has not been comprehensively investigated. We analyzed the association between RC, non-HDL-C, and cardiac function in CHD patients with T2DM. Of the 22 022 CHD patients from six hospitals in Tianjin, 5373 (24.4%) patients with T2DM had higher levels of RC and non-HDL-C (P < .001) than those without T2DM. Among CHD patients with T2DM, RC and non-HDL-C were positively associated with New York Heart Association (NYHA) class Ⅱ [RC: odds ratio (OR), 1.74; 95% confidence interval (CI), 1.50-2.01; P < .01; non-HDL-C: OR, 1.23; 95% CI, 1.15-1.31; P < .01]. After adjusting for confounding factors, this association remained (RC: OR, 1.22; 95% CI, 1.03-1.45; P < .05; non-HDL-C: OR, 1.09; 95% CI, 1.02-1.17; P < .05). These findings provide evidence of an independent positive association between RC, non-HDL-C, and NYHA functional classes. More research is warranted to confirm these findings and determine the mechanisms involved.

Unravelling lipoprotein metabolism with stable isotopes: tracing the flow

Dysregulated lipoprotein metabolism is a major cause of atherosclerotic cardiovascular disease (ASCVD). Use of stable isotope tracers and compartmental modelling have provided deeper understanding of the mechanisms underlying lipid disorders in patients at high risk of ASCVD, including familial hypercholesterolemia (FH), elevated lipoprotein(a) [Lp(a)] and metabolic syndrome (MetS). In patients with FH, deficiency in low-density lipoprotein (LDL) receptor activity not only impairs the catabolism of LDL, but also induces hepatic overproduction and decreases catabolism of triglyceride-rich lipoproteins (TRLs). Patients with elevated Lp(a) are characterized by increased hepatic secretion of Lp(a) particles. Atherogenic dyslipidemia in MetS patients relates to a combination of overproduction of very-low density lipoprotein-apolipoprotein (apo) B-100, decreased catabolism of apoB-100-containing particles, and increased catabolism of high-density lipoprotein-apoA-I particles, as well as to impaired clearance of TRLs in the postprandial state. Kinetic studies show that weight loss, fish oils, statins and fibrates have complementary modes of action that correct atherogenic dyslipidemia. Defining the kinetic mechanisms of action of proprotein convertase subtilisin/kexin type 9 and angiopoietin-like 3 inhibitors on lipid and lipoprotein mechanism in dyslipidemic subjects will further our understanding of these therapies in decreasing the development of ASCVD. "Everything changes but change itself. Everything flows and nothing remains the same... You cannot step twice into the same river, for other waters and yet others go flowing ever on." Heraclitus (c.535- c. 475 BCE).

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.

Lipoprotein(a): Knowns, unknowns and uncertainties

Over the last 10 years, there have been advances on several aspects of lipoprotein(a) which are reviewed in the present article. Since the standard immunoassays for measuring lipoprotein(a) are not fully apo(a) isoform-insensitive, the application of an LC-MS/MS method for assaying molar concentrations of lipoprotein(a) has been advocated. Genome wide association, epidemiological, and clinical studies have established high lipoprotein(a) as a causal risk factor for atherosclerotic cardiovascular diseases (ASCVD). However, the relative importance of molar concentration, apo(a) isoform size or variants within the LPA gene is still controversial. Lipoprotein(a)-raising single nucleotide polymorphisms has not been shown to add on value in predicting ASCVD beyond lipoprotein(a) concentrations. Although hyperlipoproteinemia(a) represents an important confounder in the diagnosis of familial hypercholesterolemia (FH), it enhances the risk of ASCVD in these patients. Thus, identification of new cases of hyperlipoproteinemia(a) during cascade testing can increase the identification of high-risk individuals. However, it remains unclear whether FH itself increases lipoprotein(a). The ASCVD risk associated with lipoprotein(a) seems to follow a linear gradient across the distribution, regardless of racial subgroups and other risk factors. The inverse association with the risk of developing type 2 diabetes needs consideration as effective lipoprotein(a) lowering therapies are progressing towards the market. Considering that Mendelian randomization analyses have identified the degree of lipoprotein(a)-lowering that is required to achieve ASCVD benefit, the findings of the ongoing outcome trial with pelacarsen will clarify whether dramatically lowering lipoprotein(a) levels can reduce the risk of ASCVD.

LDL cholesterol levels and in-hospital bleeding in patients on high-intensity antithrombotic therapy: findings from the CCC-ACS project

AIMS 

Emerging evidence has linked cholesterol metabolism with platelet responsiveness. We sought to examine the dose-response relationship between low-density lipoprotein cholesterol (LDL-C) and major in-hospital bleeds in acute coronary syndrome (ACS) patients.

METHODS AND RESULTS 

Among 42 378 ACS patients treated with percutaneous coronary intervention (PCI) enrolled in 240 hospitals in the Improving Care for Cardiovascular Disease in China-ACS project from 2014 to 2019, a total of 615 major bleeds, 218 ischaemic events, and 337 deaths were recorded. After controlling for baseline variables, a non-linear relationship was observed for major bleeds, with the higher risk at lower LDL-C levels. No dose-response relationship was identified for ischaemic events and mortality. A threshold value of LDL-C <70 mg/dL was associated with an increased risk for major bleeds (adjusted odds ratio: 1.49; 95% confidence interval: 1.21-1.84) in multivariable-adjusted logistic regression models and in propensity score-matched cohorts. The results were consistent in multiple sensitivity analyses. Among ticagrelor-treated patients, the LDL-C threshold for increased bleeding risk was observed at <88 mg/dL, whereas for clopidogrel-treated patients, the threshold was <54 mg/dL. Across a full spectrum of LDL-C levels, the treatment effect size associated with ticagrelor vs. clopidogrel on major bleeds favoured clopidogrel at lower LDL-C levels, but no difference at higher LDL-C levels.

CONCLUSIONS 

In a nationwide ACS registry, a non-linear association was identified between LDL-C levels and major in-hospital bleeds following PCI, with the higher risk at lower levels. As the potential for confounding may exist, further studies are warranted.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02306616.

Potential biomarker in serum for predicting susceptibility to type 2 diabetes mellitus: Free fatty acid 22:6

AIMS/INTRODUCTION

Type 2 diabetes mellitus is closely linked to increased levels of free fatty acids (FFAs) in obese individuals, although which FFA is most associated with type 2 diabetes mellitus is unclear. This study aimed to identify the specific FFAs that best predict the occurrence of type 2 diabetes mellitus in obese individuals, and assess their potential application value.

MATERIALS AND METHODS

Participants were divided into three groups: a normal weight group (n = 20), an obese group (n = 10) and a type 2 diabetes mellitus group (n = 10). FFAs in serum samples were determined by ultra-high-pressure liquid chromatography-mass spectrometry, and orthogonal partial least squares discriminant analysis models were used to study the FFA profile among the three groups.

RESULTS

Compared with the normal weight group, 14 FFAs (C8:0/10:0/14:0/16:1/18:1/20:2/ 20:3 /20:4/ 20:5/ 22:6/7:0/9:0/11:0 and C13:0) were significantly increased in the obese group, and nine FFAs (C14:0, C18:1, C20:1, C 18:2, C20:2, C20:3, C18:3, C20:5 and C22:6) were significantly increased in the type 2 diabetes mellitus group. Subsequently, the Venn diagram results showed that six FFAs (C14:0, C18:1, C20:2, C20:3, C20:5 and C22:6) were significantly increased in both the obese and type 2 diabetes mellitus groups. Among these six, C22:6 was finally identified as an independent risk factor for type 2 diabetes mellitus, and had a great potential to predict the susceptibility to type 2 diabetes mellitus (area under the curve 0.803).

CONCLUSIONS

C22:6 can be an independent risk factor for type 2 diabetes mellitus, and it has a great potential to predict the susceptibility to type 2 diabetes mellitus.

Triglyceride-rich lipoproteins and atherosclerotic cardiovascular disease risk: current status and treatments

PURPOSE OF REVIEW

The role of triglyceride-rich lipoproteins (TRLs) in the development of atherosclerotic cardiovascular disease (ASCVD) is at the forefront of current research and treatment development programs. Despite extreme lowering of LDL-cholesterol there remains a high risk of cardiovascular disease and mortality. Recent large epidemiological, genomic wide association studies and Mendelian randomization studies have identified novel mechanisms and targets regulating TRL. This review will focus on recent and ongoing clinical trials that aim to reduce cardiovascular risk by decreasing plasma levels of TRL.

RECENT FINDINGS

Ongoing efforts of basic and clinical scientist have described novel TRL regulating mechanism. The concentration on lifestyle changes is key to prevention and treatment guidelines. There is continue evidence that supports previous guidelines using fibrates alone and in combination with niacin to reduce TRLs, in special cases. The recent results from the REDUCE-IT study support the use of eicosapentaenoic acid (EPA) for risk reduction and ASCVD, but recently presented data from the Long-Term Outcome Study to Assess Statin Residual Risk Reduction With Epanova in High Cardiovascular Risk Patients with Hypertriglyceridemia and Omega-3 Fatty Acids in Elderly Patients With Acute Myocardial Infarction studies do not support the use of combination EPA/docosahexaenoic acid. The latter highlights the need for further studies into the pathways regulating ASCVD risk reduction after EPA administration. The identification of novel targets, such as apolipoprotein C3 and angiopoietin-like protein-3, are driving the development of novel treatments, and is the focus of this review.

SUMMARY

The current management of elevated triglyceride levels and the effect on cardiovascular outcomes is an emerging area of research. New data from fish oil studies suggest differences in EPA vs. EPA/docosahexaenoic acid cardio protection outcomes. The preliminary data from ongoing clinical trials of novel triglyceride-lowering therapeutics are promising. These programs will ultimately provide foundations for future triglyceride-lowering guidelines.

Association of circulating proprotein convertase subtilisin/kexin type 9 levels and the risk of incident type 2 diabetes in subjects with prediabetes: a population-based cohort study

BACKGROUND

Proprotein convertase subtilisin/kexin type 9 (PCSK9) regulates cholesterol metabolism by targeting the low-density lipoprotein receptor. Recent studies have shown that circulating PCSK9 is associated with glucose homeostasis and insulin resistance. The aim of this study was to examine the association of circulating PCSK9 levels and risk for the development of type 2 diabetes in individuals with prediabetes.

METHODS

A population-based prospective study was conducted among 4205 Chinese subjects with prediabetes (average age 56.1 ± 7.5 years). Incident type 2 diabetes was diagnosed according to 2010 American Diabetes Association criteria. Circulating PCSK9 levels were measured using a commercially available enzyme-linked immunosorbent assay (ELISA). The association of circulating PCSK9 levels with the risk of incident type 2 diabetes was assessed by Cox regression analysis.

RESULTS

During a median follow-up period of 3.1 years, 568 subjects developed type 2 diabetes. Baseline circulating PCSK9 levels were significantly higher in female subjects developing incident type 2 diabetes than in those not developing incident type 2 diabetes (p < 0.001). In female subjects, the risk of incident type 2 diabetes was significantly higher in the highest PCSK9 quartile group (hazard ratio 2.16; 95% confidence interval 1.16-4.04) than in the lowest quartile group after adjustments for age, body mass index, waist circumference, C-reactive protein, γ-glutamyltransferase, triglycerides, low-density lipoprotein cholesterol, systolic blood pressure, and homeostatic model assessment of insulin resistance score. No significant association was observed between PCSK9 and incident type 2 diabetes in male subjects.

CONCLUSION

Elevated circulating PCSK9 levels are associated with an increased incidence of type 2 diabetes in female subjects with prediabetes.

Cholesterol lowering therapies and achievement of targets for primary and secondary cardiovascular prevention in type 2 diabetes: unmet needs in a large population of outpatients at specialist clinics

BACKGROUND

The well-established benefit of Low-Dense-Lipoprotein-cholesterol (LDL-c) lowering treatments (LLTs) has led clinical guidelines to lower the cardiovascular prevention targets. Despite this, there is a surprising scarcity of real-world studies (RWS) evaluating whether recommendations are applied in the routine clinical management of patients with type 2 diabetes (T2D). We therefore evaluated, in a large RWS, the pattern of LLTs use and the achievement of LDL-c targets in patients with T2D in Italian diabetes specialist clinics.

METHODS

We collected data from 46 diabetes outpatient clinics (following 281,381 subjects), including 104,726 T2D patients, for whom use of LLTs between 2015 and 2016 was ascertained. We used the 2016 and 2019 European Atherosclerosis Society and European Society of Cardiology (EAS-ESC) guidelines to define cardiovascular risk categories, LDL-c targets, and the expected LDL-c reduction and cardiovascular benefit achievable with LLT intensification.

RESULTS

63,861 patients (61.0%) were on statin therapy, 9.2% of whom were also on ezetimibe. Almost all subjects were at high (29.3%) or very high (70.4%) cardiovascular risk, including 17% being in secondary prevention. Among very high-risk patients, 35% were not on statin despite half of them had LDL-c > 2.6 mmol/l, and only 15% of those on statins had LDL-c < 1.4 mmol/l. 83% of subjects in secondary prevention were on a statin, but half of them had LDL-c > 1.8 mmol/l. Overall, 35% and 14% of subjects achieved the LDL-c targets as suggested by 2016 and 2019 EAS-ESC Guidelines, respectively. Based on anticipated response to treatment, we estimated that 38% of the entire population would require high-intensity-statin (HI-statin), 27% a combination of HI-statin plus ezetimibe, and 27% the addition of proprotein-convertase-subtilisin/kexin-9 (PCSK9) inhibitors. These LLT intensifications would reduce the incidence of cardiovascular events by 32%, from 23.511 to 16.022 events per 100.000 patients/10-years (incidence-rate-ratio 0.68; 95% C.I 0.67-0.70, p < 0.001).

CONCLUSIONS

Despite the increase in use of LLT in T2D over the last decades, a large proportion of subjects with T2D did not achieve their LDL-c targets. Given the very high cardiovascular risk of these patients, improving LLT is expected to have a dramatic impact on cardiovascular event prevention.

Long-term prognostic utility of low-density lipoprotein (LDL) triglyceride in real-world patients with coronary artery disease and diabetes or prediabetes

BACKGROUND

Recent guidelines highlighted the association between atherosclerosis and triglyceride-enriched lipoproteins in patients with impaired glucose metabolism. However, evidence from prospective studies for long-term prognostic utility of low-density lipoprotein triglyceride (LDL-TG) in real-world patients with prediabetes (Pre-DM) or diabetes mellitus (DM) and coronary artery disease (CAD) is currently not available. The aim of the present study was to evaluate the impact of LDL-TG on major adverse cardiovascular events (MACEs) in patients with stable CAD under different glucose metabolism status.

METHODS

A total of 4381 patients with CAD were consecutively enrolled and plasma LDL-TG level was measured by an automated homogeneous assay. They were categorized according to both status of glucose metabolism [DM, Pre-DM, normal glycaemia regulation (NGR)] and tertiles of LDL-TG. All subjects were followed up for the occurrence of MACEs.

RESULTS

During a median of 5.1 (interquartile range 3.9 to 5.9) years' follow-up, 507 (11.6%) MACEs occurred. Cubic spline models showed a significant association between LDL-TG and MACEs in DM and Pre-DM but not in NGR. When the combined effect of elevated LDL-TG and glucose disorders was considered for risk stratification, the medium tertile of LDL-TG plus DM, and the highest tertile of LDL-TG plus Pre-DM or plus DM subgroups were associated with significantly higher risk of MACEs after adjustment of confounders including triglyceride [hazard ratios (95% confidence intervals): 1.843 (1.149-2.955), 1.828 (1.165-2.867), 2.212 (1.396-3.507), all p < 0.05]. Moreover, adding LDL-TG into the original model increased the C-statistic from 0.687 to 0.704 (∆C-statistic = 0.016, p = 0.028) and from 0.734 to 0.749 (∆C-statistic = 0.014, p = 0.002) in Pre-DM and DM, respectively.

CONCLUSIONS

In this longitudinal cohort study on real-world practice, higher LDL-TG was associated with worse outcomes among Pre-DM and DM patients with stable CAD.

PCSK9 inhibitor effectively attenuates cardiometabolic impairment in obese-insulin resistant rats

Long-term high-fat diet consumption causes obese-insulin resistance and cardiac mitochondrial dysfunction, leading to impaired left ventricular (LV) function. Atorvastatin effectively improved lipid profiles in obese patients. However, inadequate reduction in low density lipoprotein cholesterol (LDL-C) level was found. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor effectively reduced LDL-C levels. We hypothesized that this PCSK9 inhibitor has a greater efficacy in attenuating cardiometabolic impairments than atorvastatin in obese-insulin resistant rats. Female rats were fed with either a high fat or normal diet for 12 weeks. High fat diet fed rats (HFD) were then divided into 3 groups and were given vehicle, atorvastatin (40 mg/kg/day; s.c.), or PCSK9 inhibitor (4 mg/kg/day; s.c.) for additional 3 weeks. The metabolic parameters, cardiac and mitochondrial function and [Ca²⁺]_i transients were determined. HFD rats developed obese-insulin resistance as indicated by increased plasma insulin and HOMA index. Although high-fat diet fed rats treated with vehicle (HFV) rats had markedly impaired LV function as indicated by reduced %LVFS, impaired cardiac mitochondrial function, and [Ca²⁺]_i transient regulation, these impairments were attenuated in high-fat diet fed rats treated with atorvastatin (HFA) and high-fat diet fed rats treated with PCSK9 inhibitor (HFP) rats. However, these improvements were greater in HFP rats than HFA rats. Our findings indicated that the PCSK9 inhibitor exerted greater cardioprotection than atorvastatin through improved mitochondrial function in obese-insulin resistant rats.

Research progress on alternative non-classical mechanisms of PCSK9 in atherosclerosis in patients with and without diabetes

The proprotein convertase subtilisin/kexin type 9 (PCSK9) acts via a canonical pathway to regulate circulating low-density lipoprotein-cholesterol (LDL-C) via degradation of the LDL receptor (LDLR) on the liver cell surface. Published research has shown that PCSK9 is involved in atherosclerosis via a variety of non-classical mechanisms that involve lysosomal, inflammatory, apoptotic, mitochondrial, and immune pathways. In this review paper, we summarized these additional mechanisms and described how anti-PCSK9 therapy exerts effects through these mechanisms. These additional pathways further illustrate the regulatory role of PCSK9 in atherosclerosis and offer an in-depth interpretation of how the PCSK9 inhibitor exerts effects on the treatment of atherosclerosis.