Relationship of apolipoprotein C-III proteoform composition with ankle-brachial index and peripheral artery disease in the Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND AND AIMS: Apolipoprotein C-III (apoC-III) proteoform composition shows distinct relationships with plasma lipids and cardiovascular risk. The present study tested whether apoC-III proteoforms are associated with risk of peripheral artery disease (PAD). METHODS: ApoC-III proteoforms, i.e., native (C-III0a), and glycosylated with zero (C-III0b), one (C-III1) or two (C-III2) sialic acids, were measured by mass spectrometry immunoassay on 5,734 Multi-Ethnic Study of Atherosclerosis participants who were subsequently followed for clinical PAD over 17 years. Ankle-brachial index (ABI) was also assessed at baseline and then 3 and 10 years later in 4,830 participants. RESULTS: Higher baseline C-III0b/C-III1 and lower baseline C-III2/C-III1 were associated with slower decline in ABI (follow-up adjusted for baseline) over time, independently of cardiometabolic risk factors, and plasma triglycerides and HDL cholesterol levels (estimated difference per 1 SD was 0.31 % for both, p < 0.01). The associations between C-III2/C-III1 and changes in ABI were stronger in men (-1.21 % vs. -0.27 % in women), and in Black and Chinese participants (-0.83 % and -0.86 % vs. 0.12 % in White). Higher C-III0b/C-III1 was associated with a trend for lower risk of PAD (HR = 0.84 [95%CI: 0.67-1.04]) that became stronger after excluding participants on lipid-lowering medications (0.73 [95%CI: 0.57-0.94]). Neither change in ABI nor clinical PAD was related to total apoC-III levels. CONCLUSIONS: We found associations of apoC-III proteoform composition with changes in ABI that were independent of other risk factors, including plasma lipids. Our data further support unique properties of apoC-III proteoforms in modulating vascular health that go beyond total apoC-III levels.

Apolipoprotein C-III, familial chylomicronemia syndrome, and olezarsen.

Reducing the synthesis of apoC-III reduces fasting triglycerides in individuals lacking lipoprotein lipase activity. Recently, Stroes et al.1 published a phase 3 trial on the effects of olezarsen, a third-generation antisense oligonucleotide that blocks apoC-III mRNA, on triglycerides and risk of acute pancreatitis.

Triglyceride-rich lipoprotein, remnant cholesterol, and apolipoproteins CII, CIII, and E in patients with schizophrenia.

Patients with schizophrenia show a disproportionally increased risk of cardiovascular disease. Hypertriglyceridemia is prevalent in this population; however, how this relates to levels of remnant cholesterol, triglyceride (TG)-rich lipoprotein (TRL) particle size and composition, TG turnover, and apolipoprotein (apo) and angiopoietin-like protein (ANGPTL) concentrations is unknown. Fasting levels of cholesterol (total [TC], LDL-C, HDL-C, non-HDL-C and remnant cholesterol) and TG were determined in 110 patients diagnosed with schizophrenia, and 46 healthy controls. TRL particle size, concentration and composition, and ß-hydroxybutyrate (TG turnover marker) were assessed by NMR. Levels of apoCII, apoCIII, apoE, ANGPTL3, ANGPTL4, and ANGPTL8 were measured by ELISA, and apoCII, apoCIII and apoE were further evaluated in HDL and non-HDL fractions. Patients with schizophrenia had significantly elevated TG, TG:apoB ratio, non-HDL-C, remnant cholesterol, non-HDL-apoCII and non-HDL-apoCIII, and HDL-apoE (all P < 0.05), lower HDL-C and apoA-I (all P < 0.001), and comparable apoB, TC, TC:apoB ratio, LDL-C, ß-hydroxybutyrate, ANGPTL3, ANGPTL4 and ANGPTL8 to healthy controls. Patients had a 12.0- and 2.5-fold increase in the concentration of large and medium TRL particles respectively, but similar cholesterol:TG ratio within each particle. Plasma TG, remnant cholesterol, and large and medium TRL particle concentrations correlated strongly with apoCII, apoCIII, and apoE in the non-HDL fraction, and with apoCIII and apoE in the HDL fraction in patients with schizophrenia. Differences in TG, HDL-C, TRL particle concentrations, apoCIII, and apoE persisted after adjustment for conventional risk factors. These results are consistent with impaired TRL lipolysis and clearance in patients with schizophrenia which may be responsive to targeting apoCIII.

Elevated apolipoprotein C3 augments diabetic kidney disease and associated atherosclerosis in type 2 diabetes.

Diabetes increases the risk of both cardiovascular disease and kidney disease. Notably, most of the excess cardiovascular risk in people with diabetes is in those with kidney disease. Apolipoprotein C3 (APOC3) is a key regulator of plasma triglycerides, and it has recently been suggested to play a role in both type 1 diabetes-accelerated atherosclerosis and kidney disease progression. To investigate if APOC3 plays a role in kidney disease in people with type 2 diabetes, we analyzed plasma levels of APOC3 from the Veterans Affairs Diabetes Trial. Elevated baseline APOC3 levels predicted a greater loss of renal function. To mechanistically test if APOC3 plays a role in diabetic kidney disease and associated atherosclerosis, we treated black and tan, brachyury, WT and leptin-deficient (OB; diabetic) mice, a model of type 2 diabetes, with an antisense oligonucleotide (ASO) to APOC3 or a control ASO, all in the setting of human-like dyslipidemia. Silencing APOC3 prevented diabetes-augmented albuminuria, renal glomerular hypertrophy, monocyte recruitment, and macrophage accumulation, partly driven by reduced ICAM1 expression. Furthermore, reduced levels of APOC3 suppressed atherosclerosis associated with diabetes. This suggests that targeting APOC3 might benefit both diabetes-accelerated atherosclerosis and kidney disease.

Plozasiran (ARO-APOC3) for Severe Hypertriglyceridemia: The SHASTA-2 Randomized Clinical Trial.

Importance: Severe hypertriglyceridemia (sHTG) confers increased risk of atherosclerotic cardiovascular disease (ASCVD), nonalcoholic steatohepatitis, and acute pancreatitis. Despite available treatments, persistent ASCVD and acute pancreatitis-associated morbidity from sHTG remains. Objective: To determine the tolerability, efficacy, and dose of plozasiran, an APOC3-targeted small interfering-RNA (siRNA) drug, for lowering triglyceride and apolipoprotein C3 (APOC3, regulator of triglyceride metabolism) levels and evaluate its effects on other lipid parameters in patients with sHTG. Design, Setting, and Participants: The Study to Evaluate ARO-APOC3 in Adults With Severe Hypertriglyceridemia (SHASTA-2) was a placebo-controlled, double-blind, dose-ranging, phase 2b randomized clinical trial enrolling adults with sHTG at 74 centers across the US, Europe, New Zealand, Australia, and Canada from May 31, 2021, to August 31, 2023. Eligible patients had fasting triglyceride levels in the range of 500 to 4000 mg/dL (to convert to millimoles per liter, multiply by 0.0113) while receiving stable lipid-lowering treatment. Interventions: Participants received 2 subcutaneous doses of plozasiran (10, 25, or 50 mg) or matched placebo on day 1 and at week 12 and were followed up through week 48. Main Outcomes and Measures: The primary end point evaluated the placebo-subtracted difference in means of percentage triglyceride change at week 24. Mixed-model repeated measures were used for statistical modeling. Results: Of 229 patients, 226 (mean [SD] age, 55 [11] years; 176 male [78%]) were included in the primary analysis. Baseline mean (SD) triglyceride level was 897 (625) mg/dL and plasma APOC3 level was 32 (16) mg/dL. Plozasiran induced significant dose-dependent placebo-adjusted least squares (LS)-mean reductions in triglyceride levels (primary end point) of -57% (95% CI, -71.9% to -42.1%; P < .001), driven by placebo-adjusted reductions in APOC3 of -77% (95% CI, -89.1% to -65.8%; P < .001) at week 24 with the highest dose. Among plozasiran-treated patients, 144 of 159 (90.6%) achieved a triglyceride level of less than 500 mg/dL. Plozasiran was associated with dose-dependent increases in low-density lipoprotein cholesterol (LDL-C) level, which was significant in patients receiving the highest dose (placebo-adjusted LS-mean increase 60% (95% CI, 31%-89%; P < .001). However, apolipoprotein B (ApoB) levels did not increase, and non-high-density lipoprotein cholesterol (HDL-C) levels decreased significantly at all doses, with a placebo-adjusted change of -20% at the highest dose. There were also significant durable reductions in remnant cholesterol and ApoB48 as well as increases in HDL-C level through week 48. Adverse event rates were similar in plozasiran-treated patients vs placebo. Serious adverse events were mild to moderate, not considered treatment related, and none led to discontinuation or death. Conclusions and Relevance: In this randomized clinical trial of patients with sHTG, plozasiran decreased triglyceride levels, which fell below the 500 mg/dL threshold of acute pancreatitis risk in most participants. Other triglyceride-related lipoprotein parameters improved. An increase in LDL-C level was observed but with no change in ApoB level and a decrease in non-HDL-C level. The safety profile was generally favorable at all doses. Additional studies will be required to determine whether plozasiran favorably modulates the risk of sHTG-associated complications. Trial Registration: ClinicalTrials.gov Identifier: NCT04720534.

Olezarsen, Acute Pancreatitis, and Familial Chylomicronemia Syndrome.

BACKGROUND: Familial chylomicronemia syndrome is a genetic disorder associated with severe hypertriglyceridemia and severe acute pancreatitis. Olezarsen reduces the plasma triglyceride level by reducing hepatic synthesis of apolipoprotein C-III. METHODS: In a phase 3, double-blind, placebo-controlled trial, we randomly assigned patients with genetically identified familial chylomicronemia syndrome to receive olezarsen at a dose of 80 mg or 50 mg or placebo subcutaneously every 4 weeks for 49 weeks. There were two primary end points: the difference between the 80-mg olezarsen group and the placebo group in the percent change in the fasting triglyceride level from baseline to 6 months, and (to be assessed if the first was significant) the difference between the 50-mg olezarsen group and the placebo group. Secondary end points included the mean percent change from baseline in the apolipoprotein C-III level and an independently adjudicated episode of acute pancreatitis. RESULTS: A total of 66 patients underwent randomization; 22 were assigned to the 80-mg olezarsen group, 21 to the 50-mg olezarsen group, and 23 to the placebo group. At baseline, the mean (±SD) triglyceride level among the patients was 2630±1315 mg per deciliter, and 71% had a history of acute pancreatitis within the previous 10 years. Triglyceride levels at 6 months were significantly reduced with the 80-mg dose of olezarsen as compared with placebo (-43.5 percentage points; 95% confidence interval [CI], -69.1 to -17.9; P<0.001) but not with the 50-mg dose (-22.4 percentage points; 95% CI, -47.2 to 2.5; P = 0.08). The difference in the mean percent change in the apolipoprotein C-III level from baseline to 6 months in the 80-mg group as compared with the placebo group was -73.7 percentage points (95% CI, -94.6 to -52.8) and between the 50-mg group as compared with the placebo group was -65.5 percentage points (95% CI, -82.6 to -48.3). By 53 weeks, 11 episodes of acute pancreatitis had occurred in the placebo group, and 1 episode had occurred in each olezarsen group (rate ratio [pooled olezarsen groups vs. placebo], 0.12; 95% CI, 0.02 to 0.66). Adverse events of moderate severity that were considered by a trial investigator at the site to be related to the trial drug or placebo occurred in 4 patients in the 80-mg olezarsen group. CONCLUSIONS: In patients with familial chylomicronemia syndrome, olezarsen may represent a new therapy to reduce plasma triglyceride levels. (Funded by Ionis Pharmaceuticals; Balance ClinicalTrials.gov number, NCT04568434.).

Olezarsen for Hypertriglyceridemia in Patients at High Cardiovascular Risk.

BACKGROUND: Reducing the levels of triglycerides and triglyceride-rich lipoproteins remains an unmet clinical need. Olezarsen is an antisense oligonucleotide targeting messenger RNA for apolipoprotein C-III (APOC3), a genetically validated target for triglyceride lowering. METHODS: In this phase 2b, randomized, controlled trial, we assigned adults either with moderate hypertriglyceridemia (triglyceride level, 150 to 499 mg per deciliter) and elevated cardiovascular risk or with severe hypertriglyceridemia (triglyceride level, ≥500 mg per deciliter) in a 1:1 ratio to either a 50-mg or 80-mg cohort. Patients were then assigned in a 3:1 ratio to receive monthly subcutaneous olezarsen or matching placebo within each cohort. The primary outcome was the percent change in the triglyceride level from baseline to 6 months, reported as the difference between each olezarsen group and placebo. Key secondary outcomes were changes in levels of APOC3, apolipoprotein B, non-high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol. RESULTS: A total of 154 patients underwent randomization at 24 sites in North America. The median age of the patients was 62 years, and the median triglyceride level was 241.5 mg per deciliter. The 50-mg and 80-mg doses of olezarsen reduced triglyceride levels by 49.3 percentage points and 53.1 percentage points, respectively, as compared with placebo (P<0.001 for both comparisons). As compared with placebo, each dose of olezarsen also significantly reduced the levels of APOC3, apolipoprotein B, and non-HDL cholesterol, with no significant change in the LDL cholesterol level. The risks of adverse events and serious adverse events were similar in the three groups. Clinically meaningful hepatic, renal, or platelet abnormalities were uncommon, with similar risks in the three groups. CONCLUSIONS: In patients with predominantly moderate hypertriglyceridemia at elevated cardiovascular risk, olezarsen significantly reduced levels of triglycerides, apolipoprotein B, and non-HDL cholesterol, with no major safety concerns identified. (Funded by Ionis Pharmaceuticals; Bridge-TIMI 73a ClinicalTrials.gov number, NCT05355402.).

ANGPTL3 and ApoC-III inhibitors for treating hypertriglyceridemia in context: horses for courses?

PURPOSE OF REVIEW: Hypertriglyceridemia (HTG) is an independent and casual risk factor for atherosclerotic cardiovascular disease (ASCVD). There is an unmet need for more effective treatments for patients with HTG. Angiopoietin-like protein 3 (ANGPTL3) and apolipoprotein C-III (apoC-III) are key regulators of triglyceride-rich lipoprotein (TRL) metabolism. We review recent clinical trials targeting ANGPTL3 and apoC-III with monoclonal antibody and nucleic acid therapies, including antisense oligonucleotides and small interfering RNA. RECENT FINDINGS: ANGPTL3 and apoC-III inhibitors are effective in lowering plasma triglycerides and TRLs, with possibly greater efficacy with the inhibition of apoC-III. By contrast to ANGPTL3 inhibition that has the advantage of greater lowering of plasma low-density lipoprotein (LDL)-cholesterol and apoB levels, apoC-III inhibition only has a modest or no effect in lowering plasma LDL-cholesterol and apoB concentrations. Therapeutic inhibition of ANGPTL3 and apoC-III can correct HTG possibly by reducing production and increasing catabolism of TRL particles, but this remains to be formally investigated in patients with HTG. SUMMARY: Novel agents targeting ANGPTL3 and apoC-III can correct HTG and potentially lower risk of ASCVD in patients with HTG. The long-term safety and cost-effectiveness of these agents await confirmation in ongoing and future studies.

Brazilian Portuguese version of the Patient Competency Rating Scale (PCRS-R-BR): semantic adaptation and validity / Versão em português brasileiro da Patient Competency Rating Scale (PCRS-R-BR): adaptação semântica e validade

This study describes the adaptation of a revised Brazilian version of the Patient Competency Rating Scale (PCRS-R-BR), which focuses on executive, mnemonic, and attention functions. Evidence of content-based and external validity is also reported. The cross-cultural adaptation was conducted in five phases: 1) translations and back translations; 2) item analysis by authors; 3) classification by experts; 4) revisions and reformulations by authors; 5) pilot study with a sample of patients with mild and moderate/severe traumatic brain injury (TBI). Data were analyzed descriptively, and the PCRS-R-BR scores of groups with mild vs. moderate/severe TBI were compared using the Mann-Whitney test. Patients and their relatives were divided into groups and compared using repeated-measures analysis. The results of the PCRS-R-BR questionnaire for relatives and discrepancy scores of patients with moderate/severe TBI revealed significantly more impairment than that found in the group of patients with mild TBI. There were significant differences between item and total scores of both groups of patients and relatives. Results indicated a high level of item content agreement between experts. This study found initial evidence of PCRS-R-BR content-based and external validity when the questionnaire was applied to patients with mild and moderate/severe TBI and their relatives.

O presente artigo teve como objetivo apresentar a adaptação transcultural e evidências de validade externa e de conteúdo da versão brasileira revisada da Patient Competency Rating Scale (PCRS-R-BR), com foco nas funções executivas, mnemônicas e atencionais. A adaptação transcultural incluiu cinco fases: 1) tradução e retrotradução; 2) análise de itens por autores; 3) análise de especialistas; 4) revisões e reformulações dos autores; 5) estudo piloto em pacientes com traumatismo cranioencefálico (TCE) leve e moderado/grave. Os dados foram analisados descritivamente e os pacientes com TCE leve e moderado/grave foram comparados nos escores da PCRS-R-BR pelo teste Mann-Whitney. Os pacientes e familiares foram comparados por grupo através da análise de medidas repetidas. Os pacientes com TCE moderado/grave tiveram maior prejuízo que os pacientes com TCE leve no formulário da PCRS-R-BR dos familiares e no escore de discrepância entre pacientes e familiares. Os resultados indicam bons e altos níveis de concordância entre especialistas frente aos componentes avaliados pelos itens. Esse estudo apresentou evidências iniciais de validade de conteúdo da PCRS-R-BR para pacientes com TCE leve e moderado/severo e seus familiares.

A high-carbohydrate diet enhances the adverse effect of the S2 allele of APOC3 SstI polymorphism on the TG/HDL-C ratio only in young Chinese females

Both genetic background and diet have profound effects on plasma lipid profiles. We hypothesized that a high-carbohydrate (high-CHO) diet may affect the ratios of serum lipids and apolipoproteins (apo) differently in subjects with different genotypes of the SstI polymorphism in the apoCIII gene (APOC3). Fifty-six healthy university students (27 males and 29 females, 22.89 ± 1.80 years) were given a washout diet of 54 percent carbohydrate for 7 days, followed by a high-CHO diet of 70 percent carbohydrate for 6 days without total energy restriction. Serum triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apoB100, apoAI, and the APOC3 SstI polymorphism were analyzed. The ratios of serum lipids and apoB100/apoAI were calculated. At baseline, the TG/HDL-C ratio was significantly higher in females, but not in males, with the S2 allele. The differences in the TG/HDL-C ratio between genotypes remained the same after the washout and the high-CHO diet in females. When compared with those before the high-CHO diet, the TC/HDL-C (male S2 carriers: 3.13 ± 1.00 vs 2.36 ± 0.65, P = 0.000; male subjects with the S1S1 genotype: 2.97 ± 0.74 vs 2.09 ± 0.55, P = 0.000; female S2 carriers: 2.68 ± 0.36 vs 2.24 ± 0.37, P = 0.004; female subjects with the S1S1 genotype: 2.69 ± 0.41 vs 2.09 ± 0.31, P = 0.000) and LDL-C/HDL-C (male S2 carriers: 1.44 ± 0.71 vs 1.06 ± 0.26, P = 0.012; male subjects with the S1S1 genotype: 1.35 ± 0.61 vs 1.01 ± 0.29, P = 0.005; female S2 carriers: 1.18 ± 0.33 vs 1.00 ± 0.18, P = 0.049; female subjects with the S1S1 genotype: 1.18 ± 0.35 vs 1.04 ± 0.19, P = 0.026) ratios were significantly decreased after the high-CHO diet regardless of gender and of genotype of the APOC3 SstI polymorphism. However, in female S2 carriers, the TG/HDL-C (1.38 ± 0.46 vs 1.63 ± 0.70, P = 0.039) ratio was significantly increased after the high-CHO diet. In conclusion, the high-CHO diet has favorable effects on the TC/HDL-C and LDL-C/HDL-C ratios regardless of gender and of genotype of the APOC3 SstI polymorphism. Somehow, it enhanced the adverse effect of the S2 allele on the TG/HDL-C ratio only in females.

Myocardial infarction patients show altered lipoprotein properties and functions when compared with stable angina pectoris patients

Several parameters and risk factors were compared between Korean male myocardial infarction (MI) patients (n = 10) and angina pectoris (AP) patients (n = 17) to search unique biomarkers for myocardial infarction (MI) in lipoprotein level. Individual serum and lipoprotein fractions (VLDL, LDL, HDL2, HDL3) were isolated and analyzed by lipid and protein determination and enzyme assay. The MI group was found to have a 25 and 30% higher serum cholesterol and triacylglycerol (TG) level than the AP group, respectively, however, their body mass index (BMI), LDL-cholesterol (C), HDL-C, and glucose levels fell within the normal range. MI patients were found to have an approximately two-fold higher level of serum IL-6 and an 18% lower serum apoA-I level than that of the AP group. LDL and HDL2 fraction of the MI group were more enriched with TG than those of AP group. The increased TG was correlated well with the increased level of apoC-III in the same fraction. Cholesteryl ester transfer protein (CETP) activity and protein level were greatly increased in MI patients in the LDL and HDL3 fractions. MI patients showed more severely oxidized LDL fraction than patients in the AP group, as well as the weakest antioxidant ability of serum. Conclusively, MI patients were found to have unique serum and lipoprotein characteristics including increased IL-6 and TG in serum, with CETP and apoC-III in the LDL and HDL fractions, as well as severely impaired antioxidant ability of HDL.

Myocardial infarction patients show altered lipoprotein properties and functions when compared with stable angina pectoris patients

Several parameters and risk factors were compared between Korean male myocardial infarction (MI) patients (n = 10) and angina pectoris (AP) patients (n = 17) to search unique biomarkers for myocardial infarction (MI) in lipoprotein level. Individual serum and lipoprotein fractions (VLDL, LDL, HDL2, HDL3) were isolated and analyzed by lipid and protein determination and enzyme assay. The MI group was found to have a 25 and 30% higher serum cholesterol and triacylglycerol (TG) level than the AP group, respectively, however, their body mass index (BMI), LDL-cholesterol (C), HDL-C, and glucose levels fell within the normal range. MI patients were found to have an approximately two-fold higher level of serum IL-6 and an 18% lower serum apoA-I level than that of the AP group. LDL and HDL2 fraction of the MI group were more enriched with TG than those of AP group. The increased TG was correlated well with the increased level of apoC-III in the same fraction. Cholesteryl ester transfer protein (CETP) activity and protein level were greatly increased in MI patients in the LDL and HDL3 fractions. MI patients showed more severely oxidized LDL fraction than patients in the AP group, as well as the weakest antioxidant ability of serum. Conclusively, MI patients were found to have unique serum and lipoprotein characteristics including increased IL-6 and TG in serum, with CETP and apoC-III in the LDL and HDL fractions, as well as severely impaired antioxidant ability of HDL.