Impact of Lipoprotein(a) Level on Low-Density Lipoprotein Cholesterol- or Apolipoprotein B-Related Risk of Coronary Heart Disease.

BACKGROUND: Conventional low-density lipoprotein cholesterol (LDL-C) quantification includes cholesterol attributable to lipoprotein(a) (Lp(a)-C) due to their overlapping densities. OBJECTIVES: The purposes of this study were to compare the association between LDL-C and LDL-C corrected for Lp(a)-C (LDLLp(a)corr) with incident coronary heart disease (CHD) in the general population and to investigate whether concomitant Lp(a) values influence the association of LDL-C or apolipoprotein B (apoB) with coronary events. METHODS: Among 68,748 CHD-free subjects at baseline LDLLp(a)corr was calculated as "LDL-C-Lp(a)-C," where Lp(a)-C was 30% or 17.3% of total Lp(a) mass. Fine and Gray competing risk-adjusted models were applied for the association between the outcome incident CHD and: 1) LDL-C and LDLLp(a)corr in the total sample; and 2) LDL-C and apoB after stratification by Lp(a) mass (≥/<90th percentile). RESULTS: Similar risk estimates for incident CHD were found for LDL-C and LDL-CLp(a)corr30 or LDL-CLp(a)corr17.3 (subdistribution HR with 95% CI) were 2.73 (95% CI: 2.34-3.20) vs 2.51 (95% CI: 2.15-2.93) vs 2.64 (95% CI: 2.26-3.10), respectively (top vs bottom fifth; fully adjusted models). Categorization by Lp(a) mass resulted in higher subdistribution HRs for uncorrected LDL-C and incident CHD at Lp(a) ≥90th percentile (4.38 [95% CI: 2.08-9.22]) vs 2.60 [95% CI: 2.21-3.07]) at Lp(a) <90th percentile (top vs bottom fifth; Pinteraction0.39). In contrast, apoB risk estimates were lower in subjects with higher Lp(a) mass (2.43 [95% CI: 1.34-4.40]) than in Lp(a) <90th percentile (3.34 [95% CI: 2.78-4.01]) (Pinteraction0.49). CONCLUSIONS: Correction of LDL-C for its Lp(a)-C content provided no meaningful information on CHD-risk estimation at the population level. Simple categorization of Lp(a) mass (≥/<90th percentile) influenced the association between LDL-C or apoB with future CHD mostly at higher Lp(a) levels.

Apolipoprotein B: Bridging the Gap Between Evidence and Clinical Practice.

Despite data suggesting that apolipoprotein B (apoB) measurement outperforms low-density lipoprotein cholesterol level measurement in predicting atherosclerotic cardiovascular disease risk, apoB measurement has not become widely adopted into routine clinical practice. One barrier for use of apoB measurement is lack of consistent guidance for clinicians on how to interpret and apply apoB results in clinical context. Whereas guidelines have often provided clear low-density lipoprotein cholesterol targets or triggers to initiate treatment change, consistent targets for apoB are lacking. In this review, we synthesize existing data regarding the epidemiology of apoB by comparing guideline recommendations regarding use of apoB measurement, describing population percentiles of apoB relative to low-density lipoprotein cholesterol levels, summarizing studies of discordance between low-density lipoprotein cholesterol and apoB levels, and evaluating apoB levels in clinical trials of lipid-lowering therapy to guide potential treatment targets. We propose evidence-guided apoB thresholds for use in cholesterol management and clinical care.

Excess Apolipoprotein B and Cardiovascular Risk in Women and Men.

BACKGROUND: Low-density lipoprotein cholesterol (LDL-C) and apolipoprotein B (apoB) are highly correlated measures of atherogenic lipoproteins. OBJECTIVES: The study investigators hypothesized that excess apoB is associated with an increased risk of myocardial infarction (MI), atherosclerotic cardiovascular disease (ASCVD), and all-cause mortality. METHODS: The study included 53,484 women and 41,624 men not taking statins from the Copenhagen General Population Study. Associations of excess apoB with the risk of MI, ASCVD, and all-cause mortality were estimated by Cox proportional hazards regressions with 95% CIs. Excess apoB was defined as measured levels of apoB minus expected levels of apoB from LDL-C alone; expected levels were defined by linear regressions of LDL-C levels vs apoB levels in individuals with triglycerides ≤1 mmol/L (89 mg/dL). RESULTS: During a median follow-up of 9.6 years, 2,048 MIs, 4,282 ASCVD events, and 8,873 deaths occurred. There was a dose-dependent association between excess apoB and the risk of MI and ASCVD in both women and men, as well as an association with the risk of all-cause mortality in women. For ASCVD in women compared with those with excess apoB <11 mg/dL, the multivariable adjusted HR was 1.08 (95% CI: 0.97-1.21) for excess apoB 11 to 25 mg/dL, 1.30 (95% CI: 1.14-1.48) for 26 to 45 mg/dL, 1.34 (95% CI: 1.14-1.58) for 46 to 100 mg/dL, and 1.75 (95% CI: 1.08-2.83) for excess apoB >100 mg/dL. Corresponding HRs in men were 1.14 (95% CI: 1.02-1.26), 1.41 (95% CI: 1.26-1.57), 1.41 (95% CI: 1.25-1.60), and 1.52 (95% CI: 1.13-2.05), respectively. Results were robust across the entire LDL-C spectrum. CONCLUSIONS: Excess apoB (ie, the value of apoB above that contributed by LDL-C levels alone) is associated dose-dependently with an increased risk of MI and ASCVD in women and men. This finding demonstrates that apoB provides important predictive value beyond LDL-C across the entire LDL-C spectrum.

Relationship between serum apolipoprotein B and risk of all-cause and cardiovascular disease mortality in individuals with hypertension: a prospective cohort study.

BACKGROUND: Dyslipidemia frequently coexists with hypertension in the population. Apolipoprotein B (ApoB) is increasingly considered a more potent predictor of cardiovascular disease (CVD). Abnormal levels of serum ApoB can potentially impact the mortality risk. METHODS: The prospective cohort study employed data from the National Health and Nutrition Examination Survey (NHANES), which was performed between 2005 and 2016, with follow-ups extended until December 2019. Serum ApoB concentrations were quantified using nephelometry. In line with the NHANES descriptions and recommendations, the reference ranges for ApoB concentrations are 55-140 and 55-125 mg/dL for men and women, respectively. Participants were categorized into low, normal, and high ApoB levels. The low and high groups were combined into the abnormal group. In this study, all-cause mortality (ACM) and CVD mortality (CVM) were the endpoints. Survey-weighted cox hazards models were used for evaluating the correlation between serum ApoB levels and ACM and CVM. A generalized additive model (GAM) was employed to examine the dose-dependent relationship between ApoB levels and mortality risk. RESULTS: After a median of 95 (interquartile range: 62-135) months of follow-up, 986 all-cause and 286 CVD deaths were recorded. The abnormal ApoB group exhibited a trend toward an elevated risk of ACM in relative to the normal group (HR 1.22, 95% CI: 0.96-1.53). The risk of CVM was elevated by 76% in the ApoB abnormal group (HR 1.76, 95% CI: 1.28-2.42). According to the GAM, there existed a nonlinear association between serum ApoB levels and ACM (P = 0.005) and CVM (P = 0.009). CONCLUSIONS: In the US hypertensive population, serum Apo B levels were U-shaped and correlated with ACM and CVM risk, with the lowest risk at 100 mg/dL. Importantly, abnormal Apo B levels were related to an elevated risk of ACM and CVM. These risks were especially high at lower Apo B levels. The obtained findings emphasize the importance of maintaining appropriate Apo B levels to prevent adverse outcomes in hypertensive individuals.

Abnormal maternal apolipoprotein levels during pregnancy are risk factors for preterm birth in women with dichorionic twin pregnancies: A retrospective study.

OBJECTIVE: In singleton-pregnant women, abnormal maternal apolipoprotein levels have been confirmed as a risk factor for preterm birth. However, there are currently no studies on the relationship of the related research in twin-pregnant women. METHODS: This single-center retrospective study included 743 dichorionic twin-pregnant women who delivered between January 2019 and December 2020. Twins delivered before 37 weeks gestation were categorized as the preterm group, while those delivered at or after 37 weeks gestation were classified as the term group. Maternal serum apolipoprotein A1 (ApoA1) levels, apolipoprotein B (ApoB) levels, and the ApoB/ApoA1 ratio were measured in the first trimester(6-14 weeks), the second trimester(18-28 weeks) and the third trimester(after 28 weeks). We conducted SPSS analysis to evaluate the correlation between ApoA1 levels, ApoB levels, the ApoB/ApoA1 ratio and preterm birth. RESULTS: Among the 743 included dichorionic twin-pregnant women, 53.57 % (398/743) delivered preterm. Compared with the term group, the ApoA1 levels in the third trimester were lower (p < 0.001), while the Apo B/ApoA1 ratio was higher in the second (p = 0.01) and third trimesters in the preterm group (p = 0.001). When preterm birth was categorized as iatrogenic and spontaneous preterm birth, the results were similar. In the analysis stratified by prepregnancy BMI, a higher risk of preterm birth was associated with low ApoA1 levels and a high Apo B/ApoA1 ratio in the second and third trimesters only among the subgroup of overweight/obese dichorionic twin-pregnant women. CONCLUSIONS: Low ApoA1 levels and a high Apo B/ApoA1 ratio during the second and third trimesters were associated with a high incidence of preterm birth for overweight/obese dichorionic twin-pregnant women.

The effect of lipid-lowering therapy on lipid-related residual risk factors: a prospective study.

BACKGROUND: Remnant cholesterol (RC) and nonhigh-density lipoprotein cholesterol (nonHDL-C) are key risk factors for atherosclerotic cardiovascular disease (ASCVD), with apolipoprotein B (apoB) and lipoprotein(a) [Lp(a)] also contributing to its residual risk. However, real-world population-based evidence regarding the impact of current clinical LDL-C-centric lipid-lowering therapy (LLT) on achieving RC and nonHDL-C goals, as well as on modifying residual CVD risk factors is limited. METHODS: This prospective observational study enrolled 897 CVD patients from September, 2020 to July, 2021. All participants had previously received low-/moderate-intensity LLT and were discharged with either low-/moderate-intensity LLT or high-intensity LLT. After a median follow-up of 3 months, changes in RC, nonHDL-C, and other biomarkers were assessed. Multivariate logistic regression was performed to analyze the impact of the LLT on goal attainment. RESULTS: Among all patients, 83.50% transitioned to high-intensity LLT from low or moderate. After follow-up, the high-intensity group saw significantly greater reductions in RC (-20.51% vs. -3.90%, P = 0.025), nonHDL-C (-25.12% vs. 0.00%, P < 0.001), apoB (-19.35% vs. -3.17%, P < 0.001), triglycerides (-17.82% vs. -6.62%, P < 0.001), and LDL-C and total cholesterol. Spearman correlation analysis revealed that LDL-C reduction from current LLT was strongly correlated with nonHDL-C reduction (r = 0.87, P < 0.001). Patients who received high-intensity LLT had significant improvements in attainment of RC (from 44.2% to 60.7%, χ² = 39.23, P < 0.001) and nonHDL-C (from 19.4% to 56.9%, χ² = 226.06, P < 0.001) goals. Furthermore, multivariate logistic regression showed that high-intensity LLT was a protective factor for RC [odds ratio (OR) = 0.66; 95% confidence intervals (CI), 0.45-0.97; P = 0.033] and nonHDL-C goal attainment (OR = 0.51; 95% CI, 0.34-0.75; P < 0.001), without a significant increase of adverse reactions. CONCLUSION: Current levels of clinically prescribed LDL-C-centric treatment can reduce RC and other lipid-related residual risk factors, but high-intensity LLT is better at achieving nonHDL-C and RC goals than low-/moderate-intensity LLT, with a good safety profile. More targeted RC treatments are still needed to reduce residual lipid risk further.

Serum ApoB/ApoA1 ratio in patients with CHB and the occurrence of HBV related cirrhosis and HBV related hepatocellular carcinoma.

Clinical research has suggested that chronic HBV infection exerts a certain effect on the occurrence of cardiovascular disease by regulating cholesterol metabolism in liver cells. High serum apolipoprotein B/apolipoprotein A1 (ApoB/ApoA1) ratio plays a certain role in the above regulation, and it serves as a risk factor for cardiovascular disease. However, whether the ApoB/ApoA1 ratio is correlated with chronic HBV infection and its disease progression remains unclear. In accordance with the inclusion and exclusion criteria, all 378 participants administrated at Renmin Hospital of Wuhan University from March 2021 to March 2022, fell into Healthy Control (HC) group (50 participants), Hepatocellular carcinoma (HCC) group (107 patients), liver cirrhosis (LC) group (64 patients), chronic hepatitis B (CHB) group (62 patients), chronic hepatitis C (CHC) group (46 patients) and Hepatitis E Virus (HEV) group (49 patients). Serum ApoA1 and ApoB concentrations were measured at admission, and the ApoB/ApoA1 ratio was determined. The levels of laboratory parameters in the respective group were compared and ApoB/ApoA1 ratios in HCC patients and LC patients with different severity were further analyzed. ROC curves were plotted to analyze the early diagnostic ability of ApoB/ApoA1 ratio for HBV-associated HCC. Logistic regression and restricted cubic spline analysis were used to explore the correlation between ApoB/ApoA1 ratio and LC and HCC risk. A comparison was drawn in terms of ApoB/ApoA1 ratio between the groups, and the result was expressed in descending sequence: HEV group > CHB group > LC group > HCC group > CHC group > HC group, early-stage HCC < middle-stage HCC < advanced-stage HCC, Class A LC < Class B LC < Class C LC. Serum ApoB/ApoA1 ratio combined diagnosis with AFP exhibited the capability of increasing the detection efficacy and specificity of AFP for HCC and AFP-negative HCC. The incidence of LC and HCC in the respective logistic regression model showed a negative correlation with the serum ApoB/ApoA1 ratio in CHB patients (P < 0.05). After all confounding factors covered in this study were regulated, the result of the restricted cubic spline analysis suggested that in a certain range, serum ApoB/ApoA1 ratio showed an inverse correlation with the prevalence of LC or HCC in CHB patients. Serum ApoB/ApoA1 ratio in CHB patients may be conducive to identifying high-risk patients for HCC or LC, such that LC and HCC can be early diagnosed and treated.

The role of serum lipid in predicting coronary artery lesions and intravenous immunoglobulin resistance in Kawasaki disease: a cohort study.

OBJECTIVE: To assess the predictive value of the serum lipid profile for initial intravenous immunoglobulin (IVIG) resistance and coronary artery lesions (CALs) in patients with Kawasaki disease (KD). METHODS: This retrospective cohort study enrolled patients with KD and divided them into IVIG-responsive and IVIG-resistant groups. They were also stratified based on the presence of CALs (CALs and non-CALs groups). Clinical, echocardiographic and biochemical values were evaluated. A subgroup analysis was performed on complete and incomplete KD. Predictors of initial IVIG resistance and CALs were determined by multivariate logistic regression analysis. RESULTS: A total of 649 KD patients were enrolled: 151 had CALs and 76 had initial IVIG resistance. Low-density lipoprotein cholesterol (LDL-C) was significantly lower in the IVIG-resistant group than in the IVIG-responsive group. LDL-C and apolipoprotein (Apo) B were significantly lower in the CALs group compared with the non-CALs group. Multivariate logistic regression failed to identify the serum lipid profile (LDL-C, Apo A or Apo B) as an independent risk factor for initial IVIG resistance or CALs in KD patients. CONCLUSION: KD patients might have dyslipidaemia in the acute phase, but the serum lipid profile might not be suitable as a single predictor for initial IVIG resistance or CALs.

Impact of Direct Measurement of Small Dense Low-Density Lipoprotein Cholesterol for Long-Term Secondary Prevention in Patients with Stable Coronary Artery Disease.

BACKGROUND: This study investigated whether directly measured small dense low-density lipoprotein cholesterol (D-sdLDL-C) can predict long-term coronary artery disease (CAD) events compared with low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), apolipoprotein B (apoB), and estimated small dense low-density lipoprotein cholesterol (E-sdLDL-C) determined by the Sampson equation in patients with stable CAD. METHODS: D-sdLDL-C measured at Showa University between 2010 and 2022, and E-sdLDL-C were evaluated in 790 male and 244 female patients with stable CAD. CAD events, defined as sudden cardiac death, onset of acute coronary syndrome, and/or need for coronary revascularization, were monitored for 12 years. Cutoff lipid levels were determined by receiver operating characteristic curves. RESULTS: CAD events were observed in 238 male and 67 female patients. The Kaplan-Meier event-free survival curves showed that patients with D-sdLDL-C ≥32.1 mg/dL (0.83 mmol/L) had an increased risk for CAD events (P = 0.007), whereas risk in patients with E-sdLDL-C ≥36.2 mg/dL (0.94 mmol/L) was not increased. In the group with high D-sdLDL-C, the multivariable-adjusted hazard ratio (HR) was 1.47 (95% CI, 1.15-1.89), and it remained significant after adjustment for LDL-C, non-HDL-C, or apoB and in patients treated with statins. HRs for high LDL-C, non-HDL-C, or apoB were not statistically significant after adjustment for high D-sdLDL-C. Higher D-sdLDL-C was associated with enhanced risk of high LDL-C, non-HDL-C, and apoB (HR 1.73; 95% CI, 1.27-2.37). CONCLUSIONS: Higher D-sdLDL-C can predict long-term recurrence of CAD in stable CAD patients independently of apoB and non-HDL-C. D-sdLDL-C is an independent risk enhancer for secondary CAD prevention, whereas E-sdLDL-C is not.UMIN-CTR Clinical Trial Number: UMIN000027504.

Remnant cholesterol, LDL cholesterol, and apoB absolute mass changes explain results of the PROMINENT trial.

BACKGROUND AND AIMS: The PROMINENT trial, a cardiovascular outcome trial of the triglyceride- and remnant cholesterol-lowering agent pemafibrate, has shown neutral results despite reduction in plasma triglycerides and remnant cholesterol. We tested the hypothesis that absolute mass changes in remnant cholesterol, LDL cholesterol, and apolipoprotein B explain the results of the PROMINENT trial. METHODS: Among 108,431 individuals from the Copenhagen General Population Study (CGPS), those who met the key inclusion criteria of the PROMINENT trial were analyzed to mimic the trial design. Endpoint atherosclerotic cardiovascular disease (ASCVD) was cardiovascular death, myocardial infarction, ischemic stroke, and coronary revascularization as defined in PROMINENT. RESULTS: In the PROMINENT trial, treatment with pemafibrate resulted in -7 mg/dL (-0.18 mmol/L; -18 %) change in remnant cholesterol, +10 mg/dL (+0.26 mmol/L; +12 %) LDL cholesterol, and +5 mg/dL (+0.05 g/L; +5 %) apolipoprotein B. In the CGPS mimicking PROMINENT, the estimated hazard ratios for ASCVD were 0.97 (95 % confidence interval: 0.94-0.99) for a -7 mg/dL (-0.18 mmol/L) change in remnant cholesterol, 1.04 (1.01-1.07) for a +10 mg/dL (+0.26 mmol/L) change in LDL cholesterol, and 1.02 (1.01-1.03) for a +5 mg/dL (+0.05 g/L) change in apolipoprotein B. When combining absolute changes in remnant cholesterol, LDL cholesterol, and apolipoprotein B, the estimated hazard ratio for ASCVD was 1.05 (0.96-1.14) in the CGPS mimicking PROMINENT compared to 1.03 (0.91-1.15) in the PROMINENT trial. CONCLUSIONS: Absolute mass changes in remnant cholesterol, LDL cholesterol, and apolipoprotein B can explain results of the PROMINENT trial. The 3 mg/dL (0.08 mmol/L) higher total atherogenic cholesterol together with 5 mg/dL (0.05 g/L) higher apolipoprotein B seem to explain the trend toward more ASCVD in the pemafibrate arm.

APOB and CCL17 as mediators in the protective effect of SGLT2 inhibition against myocardial infarction: Insights from proteome-wide mendelian randomization.

AIMS: Sodium-glucose cotransporter 2 (SGLT2) inhibitors offer a novel therapeutic avenue for myocardial infarction (MI). However, the exact nature of this relationship and the underlying mechanisms are not fully understood. METHODS: Utilizing a two-sample Mendelian Randomization (MR) analysis, we elucidated the causal effects stemming from the inhibition of SGLT2 on MI. Then, The pool of 4907 circulating proteins within the plasma proteome were utilized to explore the mediators of SGLT2 inhibitors on MI. Protein-protein network and enrichment analysis were conducted to clarify the potential mechanism. Finally, employing MR analysis and meta-analysis techniques, we systematically assessed the causal associations between SGLT2 inhibition and coronary heart diseases (CHD). RESULTS: SGLT2 inhibition (per 1 SD decrement in HbA1c) was associated with reduced risk of MI (odds ratio [OR] = 0.462, [95% CI 0.222, 0.958], P = 0.038). Among 4907 circulating proteins, we identified APOB and CCL17 which were related to both SGLT2 inhibition and MI. Mediation analysis showed evidence of the indirect effect of SGLT2 inhibition on MI through APOB (ß = -0.557, 95%CI [-1.098, -0.155]) with a mediated proportion of 72%, and CCL17 (ß = -0.176, 95%CI [-0.332, -0.056]) with a mediated proportion of 17%. The meta-analysis result showed that SGLT2 inhibition was associated with a lower risk of CHD. CONCLUSION: Based on proteome-wide mendelian randomization, APOB and CCL17 were seen as mediators in the protective effect of SGLT2 inhibition against myocardial infarction.

Association of cardiac biomarkers with long-term cardiovascular events in a community cohort.

MATERIALS AND METHODS: The study assessed major adverse cardiac events (MACE) (myocardial infarction, coronary artery bypass graft, percutaneous intervention, stroke, and death. Cox proportional hazards models assessed apolipoprotein AI (ApoA1), apolipoprotein B (ApoB), ceramide score, cystatin C, galectin-3 (Gal3), LDL-C, Non-HDL-C, total cholesterol (TC), N-terminal B-type natriuretic peptide (NT proBNP), high-sensitivity cardiac troponin (HscTnI) and soluble interleukin 1 receptor-like 1. In adjusted models, Ceramide score was defined by from N-palmitoyl-sphingosine [Cer(16:0)], N-stearoyl-sphingosine [Cer(18:0)], N-nervonoyl-sphingosine [Cer(24:1)] and N-lignoceroyl-sphingosine [Cer(24:0)]. Multi-biomarker models were compared with C-statistics and Integrated Discrimination Index (IDI). RESULTS: A total of 1131 patients were included. Adjusted NT proBNP per 1 SD resulted in a 31% increased risk of MACE/death (HR = 1.31) and a 31% increased risk for stroke/MI (HR = 1.31). Adjusted Ceramide per 1 SD showed a 13% increased risk of MACE/death (HR = 1.13) and a 29% increased risk for stroke/MI (HR = 1.29). These markers added to clinical factors for both MACE/death (p = 0.003) and stroke/MI (p = 0.034). HscTnI was not a predictor of outcomes when added to the models. DISCUSSION: Ceramide score and NT proBNP improve the prediction of MACE and stroke/MI in a community primary prevention cohort.

In a community cohort, where a wide range of biomarkers were evaluated, Ceramide score provided additive value over traditional cardiac risk factors alone for predicting stroke/MI. NT ProBNP provided additive value in prediction of MACE/death. Other biomarkers failed to improve the discrimination of these models.

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.).

Targeting the vivid facets of apolipoproteins as a cardiovascular risk factor in rheumatoid arthritis.

Mostly, cardiovascular diseases are blamed for casualties in rheumatoid arthritis (RA) patients. Customarily, dyslipidemia is probably the most prevalent underlying cause of untimely demise in people suffering from RA as it hastens the expansion of atherosclerosis. The engagement of inflammatory cytokines like tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6), etc., is crucial in the progression and proliferation of both RA and abnormal lipid parameters. Thus, lipid abnormalities should be monitored frequently in patients with both primary and advanced RA stages. An advanced lipid profile examination, i.e., direct role of apolipoproteins associated with various lipid molecules is a more dependable approach for better understanding of the disease and selecting suitable therapeutic targets. Therefore, studying their apolipoproteins is more relevant than assessing RA patients' altered lipid profile levels. Among the various apolipoprotein classes, Apo A1 and Apo B are primarily being focused. In addition, it also addresses how calculating Apo B:Apo A1 ratio can aid in analyzing the disease's risk. The marketed therapies available to control lipid abnormalities are associated with many other risk factors. Hence, directly targeting Apo A1 and Apo B would provide a better and safer option.

Discordance between LDL-C and apolipoprotein B is associated with large-artery-atherosclerosis ischemic stroke in patients ⩽70 years of age.

BACKGROUND AND AIMS: Low density lipoprotein (LDL-C) and other atherogenic lipoproteins are coated by apolipoprotein B100 (apoB). The correlation between LDL-C and apoB is usually thight, but in some cases LDL-C underestimates apoB levels and residual cardiovascular risk. We aimed to assess if a discordance of LDL-C-levels with apoB levels is associated with LAA stroke. METHODS: We included patients with an acute ischemic stroke from two prospective studies enrolled at the University Hospital Bern, Basel and Zurich, Switzerland. LDL-C and apoB were measured within 24 h of symptom onset. By linear regression, for each LDL-C, we computed the expected apoB level assuming a perfect correlation. Higher-than-expected apoB was defined as apoB level being in the upper residual tertile. RESULTS: Overall, we included 1783 patients, of which 260 had a LAA stroke (15%). In the overall cohort, higher-than-expected apoB values were not associated with LAA. However, a significant interaction with age was present. Among the 738 patients ⩽70 years of age, a higher-than-expected apoB was more frequent in patients with LAA- versus non LAA-stroke (48% vs 36%, p = 0.02). In multivariate analysis, a higher-than-expected apoB was associated with LAA stroke (aOR = aOR 2.48, 95%CI 1.14-5.38). Among those aged ⩽70 years and with LAA, 11.7% had higher than guideline-recommended apoB despite LDL-C ⩽ 1.8 mmol/L (<70 mg/dl), compared to 5.9% among patients with other stroke etiologies (p = 0.04). A triglyceride cut-off of ⩾0.95 mmol/L had, in external validation, a sensitivity of 71% and specificity of 52% for apoB ⩾ 0.65 g/L among patients with LDL-C <1.8 mmol/L. CONCLUSIONS: Among patients aged ⩽70 years, a higher-than-expected apoB was independently associated with LAA stroke. Measuring apoB may help identify younger stroke patients potentially benefiting from intensified lipid-lowering therapy.

Intracellular tPA-PAI-1 interaction determines VLDL assembly in hepatocytes.

Apolipoprotein B (apoB)-lipoproteins initiate and promote atherosclerotic cardiovascular disease. Plasma tissue plasminogen activator (tPA) activity is negatively associated with atherogenic apoB-lipoprotein cholesterol levels in humans, but the mechanisms are unknown. We found that tPA, partially through the lysine-binding site on its Kringle 2 domain, binds to the N terminus of apoB, blocking the interaction between apoB and microsomal triglyceride transfer protein (MTP) in hepatocytes, thereby reducing very-low-density lipoprotein (VLDL) assembly and plasma apoB-lipoprotein cholesterol levels. Plasminogen activator inhibitor 1 (PAI-1) sequesters tPA away from apoB and increases VLDL assembly. Humans with PAI-1 deficiency have smaller VLDL particles and lower plasma levels of apoB-lipoprotein cholesterol. These results suggest a mechanism that fine-tunes VLDL assembly by intracellular interactions among tPA, PAI-1, and apoB in hepatocytes.

Apolipoprotein B compared with low-density lipoprotein cholesterol in the atherosclerotic cardiovascular diseases risk assessment.

The subendothelial retention of apolipoprotein B (apoB)-containing lipoproteins is a critical step in the initiation of pro-atherosclerotic processes. Recent genetic and clinical evidence strongly supports the concept that the lipid content of the particles is secondary to the number of circulating atherogenic particles that are trapped within the arterial lumen. Since each low-density lipoproteins (LDL) particle contains one apoB molecule, as do intermediate density lipoprotein (IDL) and very low-density lipoprotein (VLDL) particles, apoB level represents the total number of atherogenic lipoproteins, which is independent of particle density, and not affected by the heterogeneity of particle cholesterol content (clinically evaluated by LDL-cholesterol level). From this perspective, apoB is proposed as a better proxy to LDL-cholesterol for assessing atherosclerotic cardiovascular disease risk, especially in specific subgroups of patients, including subjects with diabetes mellitus, with multiple cardiometabolic risk factors (obesity, metabolic syndrome, insulin resistance, and hypertension) and with high triglyceride levels and very low LDL-cholesterol levels. Therefore, given the causal role of LDL-cholesterol in atherosclerotic cardiovascular disease (ASCVD) development, routine measurement of both LDL-cholesterol and apoB is of utmost importance to properly estimate global cardiovascular risk and to determine the 'residual' risk of ASCVD in patients receiving therapy, as well as to monitor therapeutic effectiveness.

Loss of hepatic SMLR1 causes hepatosteatosis and protects against atherosclerosis due to decreased hepatic VLDL secretion.

BACKGROUND AND AIMS: The assembly and secretion of VLDL from the liver, a pathway that affects hepatic and plasma lipids, remains incompletely understood. We set out to identify players in the VLDL biogenesis pathway by identifying genes that are co-expressed with the MTTP gene that encodes for microsomal triglyceride transfer protein, key to the lipidation of apolipoprotein B, the core protein of VLDL. Using human and murine transcriptomic data sets, we identified small leucine-rich protein 1 ( SMLR1 ), encoding for small leucine-rich protein 1, a protein of unknown function that is exclusively expressed in liver and small intestine. APPROACH AND RESULTS: To assess the role of SMLR1 in the liver, we used somatic CRISPR/CRISPR-associated protein 9 gene editing to silence murine Smlr1 in hepatocytes ( Smlr1 -LKO). When fed a chow diet, male and female mice show hepatic steatosis, reduced plasma apolipoprotein B and triglycerides, and reduced VLDL secretion without affecting microsomal triglyceride transfer protein activity. Immunofluorescence studies show that SMLR1 is in the endoplasmic reticulum and Cis-Golgi complex. The loss of hepatic SMLR1 in female mice protects against diet-induced hyperlipidemia and atherosclerosis but causes NASH. On a high-fat, high-cholesterol diet, insulin and glucose tolerance tests did not reveal differences in male Smlr1 -LKO mice versus controls. CONCLUSIONS: We propose a role for SMLR1 in the trafficking of VLDL from the endoplasmic reticulum to the Cis-Golgi complex. While this study uncovers SMLR1 as a player in the VLDL assembly, trafficking, and secretion pathway, it also shows that NASH can occur with undisturbed glucose homeostasis and atheroprotection.

Anti-inflammatory function of apolipoprotein B-depleted plasma is impaired in non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is associated with an increased risk of cardiovascular events. HDL exerts various protective functions on the cardiovascular system including anti-inflammatory activity by suppressing adhesion molecules expression in inflammation-induced endothelial cells. This study was designed to search if the anti-inflammatory capacity of apolipoprotein B-depleted plasma (apoB-depleted plasma) is altered in NAFLD patients. METHODS: A total of 83 subjects including 42 NAFLD and 41 control subjects were included in this cross-sectional study. Anti-inflammatory function of HDL was determined as the ability of apoB-depleted plasma to inhibit tumor necrosis factor-α (TNF-α)-induced expression of adhesion molecules in human umbilical vein endothelial cells (HUVECs). RESULTS: Incubation of inflammation-stimulated HUVECs with the NAFLD patients' apo-B depleted plasma led to higher levels of expression of adhesion molecules compared to the control subjects' plasma samples, reflecting an impaired anti-inflammatory capacity of apoB-depleted plasma in the NAFLD patients. Impaired anti-inflammatory capacity of apoB-depleted plasma was correlated with fatty liver and obesity indices. After adjustment with obesity indices, the association of anti-inflammatory capacity of apoB-depleted plasma with NAFLD remained significant. CONCLUSION: Impaired anti-inflammatory activity of apoB-depleted plasma was independently associated with NAFLD.