Do triglyceride-lowering drugs decrease risk of cardiovascular disease?

A novel fully human anti-NT-ANGPTL3 antibody from phage display library exhibits potent ApoB, TG, and LDL-C lowering activities in hyperlipidemia mice

Dyslipidemia is characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and TG-rich lipoprotein (TGRLs) in circulation, and is closely associated with the incidence and development of cardiovascular disease. Angiopoietin-like protein 3 (ANGPTL3) deficiency has been identified as a cause of familial combined hypolipidemia in humans, which allows it to be an important therapeutic target for reducing plasma lipids. Here, we report the discovery and characterization of a novel fully human antibody F1519-D95aA against N-terminal ANGPTL3 (NT-ANGPTL3), which potently inhibits NT-ANGPTL3 with a KD as low as 9.21 nM. In hyperlipidemic mice, F1519-D95aA shows higher apolipoprotein B (ApoB) and TG-lowering, and similar LDL-C reducing activity as compared to positive control Evinacumab (56.50% vs 26.01% decrease in serum ApoB levels, 30.84% vs 25.28% decrease in serum TG levels, 23.32% vs 22.52% decrease in serum LDLC levels, relative to vehicle group). Molecular docking and binding energy calculations reveal that the F1519-D95aA-ANGPTL3 complex (10 hydrogen bonds, -65.51 kcal/mol) is more stable than the Evinacumab-ANGPTL3 complex (4 hydrogen bonds, -63.76 kcal/mol). Importantly, F1519-D95aA binds to ANGPTL3 with different residues in ANGPTL3 from Evinacumab, suggesting that F1519-D95aA may be useful for the treatment of patients resistant to Evinacumab. In conclusion, F1519-D95aA is a novel fully human anti-NT-ANGPTL3 antibody with potent plasma ApoB, TG, and LDL-C lowering activities, which can potentially serve as a therapeutic agent for hyperlipidemia and relevant cardiovascular diseases.

A bifunctional anti-PCSK9 scFv/Exendin-4 fusion protein exhibits enhanced lipid-lowering effects via targeting multiple signaling pathways in HFD-fed mice

Fusion protein which encompasses more than one functional component, has become one of the most important representatives of macromolecular drugs for disease treatment since that monotherapy itself might not be effective enough to eradicate the disease. In this study, we sought to construct a bifunctional antibody fusion protein by fusing anti-PCSK9 scFv with Exendin-4 for simultaneously lowering both LDL-C and TG. Firstly, three Ex4-anti-PCSK9 scFv fusion proteins were constructed by genetically connecting the C-terminal of Exendin-4 to the N-terminal of anti-PCSK9 scFv through various flexible linker peptides (G4S)n (n = 2, 3, 4). After soluble expression in E. coli, the most potent Ex4-(G4S)4-anti-PCSK9 scFv fusion protein was selected based on in vitro activity assays. Then, we investigated the in vivo therapeutic effects of Ex4-(G4S)4-anti-PCSK9 scFv on the serum lipid profile and bodyweight changes as well as underlying molecular mechanism in HFD-fed C57BL/6 mice. The data showed that Ex4-(G4S)4-anti-PCSK9 scFv exhibits enhanced effects of lowering both LDL-C and TG in serum, reducing food intake and body weight via blocking PCSK9/LDLR, activating AMPK/SREBP-1 pathways, and up-regulating sirt6. Conclusively, Ex4-(G4S)4-anti-PCSK9 has the potential to serve as a promising therapeutic agent for effectively treating dyslipidemia with high levels of both LDL-C and TG.

Weight reduction added to CPAP decreases blood pressure and triglyceride level in OSA: systematic review and meta-analysis

Obstructive sleep apnea (OSA) is associated with treatment‐resistant hypertension and high cardiovascular risk. Continuous positive airway pressure (CPAP) fails to reduce cardiovascular risks consistently. Obesity and OSA show reciprocal association and they synergistically increase hypertension via different pathways. Our meta‐analysis aimed to assess the cardiovascular benefits of combining weight loss (WL) with CPAP (vs. WL or CPAP alone) in OSA. Outcomes included systolic and diastolic blood pressure (BP) and blood lipid parameters. We explored Medline, Embase, Cochrane, and Scopus. Eight randomized controlled studies (2627 patients) were included. The combined therapy decreased systolic BP more than CPAP alone. Weighted mean difference (WMD) for CPAP + WL versus CPAP was −8.89 mmHg, 95% confidence interval (95% CI; −13.67 to −4.10, p < 0.001) for systolic BP. For diastolic BP, this decrease was not significant. In case of blood lipids, the combined treatment decreased triglyceride levels more than CPAP alone (WMD = −0.31, 95% CI −0.58 to −0.04, p = 0.027). On the other hand, addition of CPAP to WL failed to suppress BP further. The certainty of evidence according to GRADE was very low to moderate. In conclusion, our results showed that the addition of WL to CPAP significantly improved BP and blood lipid values in OSA. On the other hand, the addition of CPAP to WL could not significantly improve BP or blood lipid values. Review protocol: PROSPERO CRD42019138998.

Familial hypertriglyceridemia/polygenic hypertrigliceridemia

For decades, familial hypertriglyceridemia (HTG) has been considered a specific entity characterized by an increase in VLDL particles and an autosomal dominant inheritance pattern. In the genomics era, it has been proven that familial HTG, although it could be grouped in families, had a polygenic inheritance in which the phenotype would be determined by concomitant environmental factors. Hence its inclusion in the group of polygenic HTGs. Clinically, they are characterized by moderate HTG, with the consequent increase in cardiovascular risk, and in rare cases, by severe HTG with risk of acute pancreatitis. Treatment will be based on controlling environmental factors, implementing hygienic-dietetic measures and sometimes drugs, to reduce cardiovascular risk in moderate HTGs and acute pancreatitis risk in severe HTGs.

The Impact of Dietary Glycemic Index and Glycemic Load on Postprandial Lipid Kinetics, Dyslipidemia and Cardiovascular Risk

Many recent studies have acknowledged postprandial hypetriglyceridemia as a distinct risk factor for cardiovascular disease. This dysmetabolic state is the result of the hepatic overproduction of very low-density lipoproteins (VLDLs) and intestinal secretion of chylomicrons (CMs), which leads to highly atherogenic particles and endothelial inflammation. Postprandial lipid metabolism does not only depend on consumed fat but also on the other classes of nutrients that a meal contains. Various mechanisms through which carbohydrates exacerbate lipidemia have been identified, especially for fructose, which stimulates de novo lipogenesis. Glycemic index and glycemic load, despite their intrinsic limitations, have been used as markers of the postprandial glucose and insulin response, and their association with metabolic health and cardiovascular events has been extensively studied with contradictory results. This review aims to discuss the importance and pathogenesis of postprandial hypertriglyceridemia and its association with cardiovascular disease. Then, we describe the mechanisms through which carbohydrates influence lipidemia and, through a brief presentation of the available clinical studies on glycemic index/glycemic load, we discuss the association of these indices with atherogenic dyslipidemia and address possible concerns and implications for everyday practice.

Omega-3 Fatty Acids for the Management of Hypertriglyceridemia: A Science Advisory From the American Heart Association

Hypertriglyceridemia (triglycerides 200-499 mg/dL) is relatively common in the United States, whereas more severe triglyceride elevations (very high triglycerides, ≥500 mg/dL) are far less frequently observed. Both are becoming increasingly prevalent in the United States and elsewhere, likely driven in large part by growing rates of obesity and diabetes mellitus. In a 2002 American Heart Association scientific statement, the omega-3 fatty acids (n-3 FAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were recommended (at a dose of 2-4 g/d) for reducing triglycerides in patients with elevated triglycerides. Since 2002, prescription agents containing EPA+DHA or EPA alone have been approved by the US Food and Drug Administration for treating very high triglycerides; these agents are also widely used for hypertriglyceridemia. The purpose of this advisory is to summarize the lipid and lipoprotein effects resulting from pharmacological doses of n-3 FAs (>3 g/d total EPA+DHA) on the basis of new scientific data and availability of n-3 FA agents. In treatment of very high triglycerides with 4 g/d, EPA+DHA agents reduce triglycerides by ≥30% with concurrent increases in low-density lipoprotein cholesterol, whereas EPA-only did not raise low-density lipoprotein cholesterol in very high triglycerides. When used to treat hypertriglyceridemia, n-3 FAs with EPA+DHA or with EPA-only appear roughly comparable for triglyceride lowering and do not increase low-density lipoprotein cholesterol when used as monotherapy or in combination with a statin. In the largest trials of 4 g/d prescription n-3 FA, non-high-density lipoprotein cholesterol and apolipoprotein B were modestly decreased, indicating reductions in total atherogenic lipoproteins. The use of n-3 FA (4 g/d) for improving atherosclerotic cardiovascular disease risk in patients with hypertriglyceridemia is supported by a 25% reduction in major adverse cardiovascular events in REDUCE-IT (Reduction of Cardiovascular Events With EPA Intervention Trial), a randomized placebo-controlled trial of EPA-only in high-risk patients treated with a statin. The results of a trial of 4 g/d prescription EPA+DHA in hypertriglyceridemia are anticipated in 2020. We conclude that prescription n-3 FAs (EPA+DHA or EPA-only) at a dose of 4 g/d (>3 g/d total EPA+DHA) are an effective and safe option for reducing triglycerides as monotherapy or as an adjunct to other lipid-lowering agents.

Obesity in older adults: Effect of degree of weight loss on cardiovascular markers and medications

Obesity worsens the age-related tendency towards cardiovascular disease and diabetes. Older adults are vulnerable to medication adverse effects. Intentional weight loss in older adults with obesity has been shown to improve cardiovascular and glycaemic markers. The effect of rapid weight loss induced by very-low-calorie diets (VLCDs) on these markers has not been evaluated in this group. In this 12-week study, participants were randomized to one of healthy eating, hypocaloric diet or VLCD, all combined with three times weekly exercise (Ex/HE, Ex/Diet, Ex/VLCD, respectively). The effects of these interventions on weight, blood pressure, lipids, glucose and HbA_1c , inflammatory markers and cardiovascular and diabetes medication changes were measured. Weight loss was 3.7%, 5.1% and 11.1% in Ex/HE, Ex/Diet and Ex/VLCD, respectively. There were significant improvements in HbA_1c in all groups, but by the greatest degree in Ex/VLCD (0.18 ± 0.07%, 0.18 ± 0.06% and 0.59 ± 0.13%, respectively). Similar patterns were seen in total cholesterol (0.13 ± 0.15, 0.21 ± 0.11 and 0.53 ± 0.13 mmol/L, respectively, P = .047), triglycerides (0.35 ± 0.13, 0.20 ± 0.10 and 0.51 ± 0.09 mmol/L, respectively, P = .011) and systolic blood pressure (9 ± 2, 2 ± 3 and 14 ± 3 mmHg respectively, P = .025). There were no between-group differences in fasting glucose, high-density lipoprotein (HDL) cholesterol, LDL-C and inflammatory markers. Reductions in anti-hypertensive or diabetes medication were made in 4/29, 7/36 and 16/37 participants in Ex/HE, Ex/Diet and Ex/VLCD, respectively (P = .017). Significant weight loss achieved with a VLCD gave rise to improvements in multiple cardiovascular risk markers, despite reduction in medication. Weight loss is an under-utilized method of cardiovascular risk management in this group.

An updated review of lipid-modifying therapy

Statin drugs reduce low-density lipoprotein (LDL)-cholesterol (LDL-C) and cardiovascular risk. Ezetimibe may be used to supplement statin therapy, or used alone in cases of statin intolerance. Statin-associated side effects do occur, especially muscle symptoms and new onset diabetes, but they do not detract from the benefits of statin therapy. Inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9) reduce LDL-C and cardiovascular risk. Evolocumab is subsidised in Australia for patients with familial hypercholesterolaemia when LDL-C is not adequately controlled with maximum doses of statin or ezetimibe or when statin therapy is contraindicated. Fenofibrate reduces triglycerides and cardiovascular risk in patients with type 2 diabetes when triglycerides are elevated and high-density lipoprotein (HDL) is low. A role for dietary omega-3 fatty acids and esters in reducing cardiovascular risk remains controversial. All cases of secondary cardiovascular disease prevention merit intensive lipid therapy, unless a contraindication exists. Lipid therapy is justified in cases of primary prevention when absolute risk is high, especially when lipids are highly elevated or when multiple risk factors are present. Clinical management requires a focus on the predominant lipid disorder present, namely hypercholesterolaemia, hypertriglyceridaemia or combined hyperlipidaemia. There is an ongoing problem of poor long term persistence on lipid therapy, as well as reduced awareness by practitioners of poor risk factor control.

Triglyceride-lowering trials

PURPOSE OF REVIEW

We provide an overview of current evidence about the independent role of high triglyceride levels for cardiovascular risk and for acute pancreatitis.

RECENT FINDINGS

Natural experiments of Mendelian randomization have given us a deeper understanding about the molecular pathways involved in triglyceride metabolism. Individuals with low-triglyceride levels generally have lower rates of cardiovascular disease (CVD). There has been a significant growth in the development of new agents that modulate enzymes involved in a variety of aspects of triglyceride packaging into VLDL or chylomicron particles, and triglyceride catabolism. Antisense inhibitors of apolipoprotein CIII are being tested, as are a variety of agents designed to increase lipoprotein lipase activity. Large-scale trials are underway with purified fatty acid (FA) formulations in over 20 000 individuals in aggregate. A large study of a new fibrate is underway.

SUMMARY

A focus on patients with elevated triglyceride levels is a new paradigm not previously the focus of large trials. Clinical outcome data on cardiovascular risk reductions remains sparse. Some drugs are already approved for use in rare inherited disorders predisposing to severe hypertriglyceridaemia and acute pancreatitis. Safety and costs issues are critical.