Cholesterol not particle concentration mediates the atherogenic risk conferred by apolipoprotein B particles: a Mendelian randomization analysis

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.

Discordance among apoB, non-high-density lipoprotein cholesterol, and triglycerides: implications for cardiovascular prevention

BACKGROUND AND AIMS

Despite growing evidence that apolipoprotein B (apoB) is the most accurate marker of atherosclerotic cardiovascular disease (ASCVD) risk, its adoption in clinical practice has been low. This investigation sought to determine whether low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (HDL-C), and triglycerides are sufficient for routine cardiovascular care.

METHODS

A sample of 293 876 UK Biobank adults (age: 40-73 years, 42% men), free of cardiovascular disease, with a median follow-up for new-onset ASCVD of 11 years was included. Distribution of apoB at pre-specified levels of LDL-C, non-HDL-C, and triglycerides was examined graphically, and 10-year ASCVD event rates were compared for high vs. low apoB. Residuals of apoB were constructed after regressing apoB on LDL-C, non-HDL-C, and log-transformed triglycerides and used as predictors in a proportional hazards regression model for new-onset ASCVD adjusted for standard risk factors, including HDL-C.

RESULTS

ApoB was highly correlated with LDL-C and non-HDL-C (Pearson's r = .96, P < .001 for both) but less so with log triglycerides (r = .42, P < .001). However, apoB ranges necessary to capture 95% of all observations at pre-specified levels of LDL-C, non-HDL-C, or triglycerides were wide, spanning 85.8-108.8 md/dL when LDL-C 130 mg/dL, 88.3-112.4 mg/dL when non-HDL-C 160 mg/dL, and 67.8-147.4 md/dL when triglycerides 115 mg/dL. At these levels (±10 mg/dL), 10-year ASCVD rates for apoB above mean + 1 SD vs. below mean - 1 SD were 7.3 vs. 4.0 for LDL-C, 6.4 vs. 4.6 for non-HDL-C, and 7.0 vs. 4.6 for triglycerides (all P < .001). With 19 982 new-onset ASCVD events on follow-up, in the adjusted model, residual apoB remained statistically significant after accounting for LDL-C and HDL-C (hazard ratio 1.06, 95% confidence interval 1.0-1.07), after accounting for non-HDL-C and HDL-C (hazard ratio 1.04, 95% confidence interval 1.03-1.06), and after accounting for triglycerides and HDL-C (hazard ratio 1.13, 95% confidence interval 1.12-1.15). None of the residuals of LDL-C, non-HDL-C, or of log triglycerides remained significant when apoB was included in the model.

CONCLUSIONS

High variability of apoB at individual levels of LDL-C, non-HDL-C, and triglycerides coupled with meaningful differences in 10-year ASCVD rates and significant residual information contained in apoB for prediction of new-onset ASCVD events demonstrate that LDL-C, non-HDL-C, and triglycerides are not adequate proxies for apoB in clinical care.

Modification of lipoprotein metabolism and function driving atherogenesis in diabetes

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease, characterized by raised blood glucose levels and impaired lipid metabolism resulting from insulin resistance and relative insulin deficiency. In diabetes, the peculiar plasma lipoprotein phenotype, consisting in higher levels of apolipoprotein B-containing lipoproteins, hypertriglyceridemia, low levels of HDL cholesterol, elevated number of small, dense LDL, and increased non-HDL cholesterol, results from an increased synthesis and impaired clearance of triglyceride rich lipoproteins. This condition accelerates the development of the atherosclerotic cardiovascular disease (ASCVD), the most common cause of death in T2DM patients. Here, we review the alteration of structure, functions, and distribution of circulating lipoproteins and the pathophysiological mechanisms that induce these modifications in T2DM. The review analyzes the influence of diabetes-associated metabolic imbalances throughout the entire process of the atherosclerotic plaque formation, from lipoprotein synthesis to potential plaque destabilization. Addressing the different pathophysiological mechanisms, we suggest improved approaches for assessing the risk of adverse cardiovascular events and clinical strategies to reduce cardiovascular risk in T2DM and cardiometabolic diseases.

Non-High-Density Lipoprotein Cholesterol Levels From Childhood to Adulthood and Cardiovascular Disease Events

Importance

Elevated non-high-density lipoprotein cholesterol (non-HDL-C; a recommended measure of lipid-related cardiovascular risk) is common in children and increases risk of adult cardiovascular disease (CVD). Whether resolution of elevated childhood non-HDL-C levels by adulthood is associated with reduced risk of clinical CVD events is unknown.

Objective

To examine the associations of non-HDL-C status between childhood and adulthood with incident CVD events.

Design, Setting, and Participants

Individual participant data from 6 prospective cohorts of children (mean age at baseline, 10.7 years) in the US and Finland. Recruitment took place between 1970 and 1996, with a final follow-up in 2019.

Exposures

Child (age 3-19 years) and adult (age 20-40 years) non-HDL-C age- and sex-specific z scores and categories according to clinical guideline-recommended cutoffs for dyslipidemia.

Main Outcomes and Measures

Incident fatal and nonfatal CVD events adjudicated by medical records.

Results

Over a mean length of follow-up of 8.9 years after age 40 years, 147 CVD events occurred among 5121 participants (60% women; 15% Black). Both childhood and adult non-HDL-C levels were associated with increased risk of CVD events (hazard ratio [HR], 1.42 [95% CI, 1.18-1.70] and HR, 1.50 [95% CI, 1.26-1.78] for a 1-unit increase in z score, respectively), but the association for childhood non-HDL-C was reduced when adjusted for adult levels (HR, 1.12 [95% CI, 0.89-1.41]). A complementary analysis showed that both childhood non-HDL-C levels and the change between childhood and adulthood were independently associated with the outcome, suggesting that from a preventive perspective, both childhood non-HDL-C levels and the change into adulthood are informative. Compared with those whose non-HDL-C levels remained within the guideline-recommended range in childhood and adulthood, participants who had incident non-HDL-C dyslipidemia from childhood to adulthood and those with persistent dyslipidemia had increased risks of CVD events (HR, 2.17 [95% CI, 1.00-4.69] and HR, 5.17 [95% CI, 2.80-9.56], respectively). Individuals who had dyslipidemic non-HDL-C in childhood but whose non-HDL-C levels were within the guideline-recommended range in adulthood did not have a significantly increased risk (HR, 1.13 [95% CI, 0.50-2.56]).

Conclusions and Relevance

Individuals with persistent non-HDL-C dyslipidemia from childhood to adulthood had an increased risk of CVD events, but those in whom dyslipidemic non-HDL-C levels resolve by adulthood have similar risk to individuals who were never dyslipidemic. These findings suggest that interventions to prevent and reduce elevated childhood non-HDL-C levels may help prevent premature CVD.

Mendelian randomization studies on coronary artery disease: a systematic review and meta-analysis

BACKGROUND

Coronary artery disease (CAD) remains one of the leading causes of mortality worldwide. We aimed to summarize what is currently known with regard to causal modifiable risk factors associated with CAD in populations of diverse ancestries through conducting a systematic review and meta-analysis of Mendelian randomization (MR) studies on CAD.

METHODS

The databases Embase, Medline, Cochrane Library and Web of Science were searched on the 19th and 20th of December 2022 for MR studies with CAD as a primary outcome; keywords of the search strategy included "coronary artery disease" and "mendelian randomization". Studies were included if they were published in the English language, included only human participants, employed Mendelian randomization as the primary methodology and studied CAD as the outcome of interest. The exclusion criteria resulted in the removal of studies that did not align with the predefined inclusion criteria, as well as studies which were systematic reviews themselves, and used the same exposure and outcome source as another study. An ancestry-specific meta-analysis was subsequently conducted on studies which investigated either body mass index, lipid traits, blood pressure or type 2 diabetes as an exposure variable. Assessment of publication bias and sensitivity analyses was conducted for risk of bias assessment in the included studies.

RESULTS

A total of 1781 studies were identified through the database searches after de-duplication was performed, with 47 studies included in the quantitative synthesis after eligibility screening. Approximately 80% of all included study participants for MR studies on CAD were of European descent irrespective of the exposure of interest, while no study included individuals of African ancestry. We found no evidence of differences in terms of direction of causation between ancestry groups; however, the strength of the respective relationships between each exposure and CAD were different, with this finding most evident when blood pressure was the exposure of interest.

CONCLUSIONS

Findings from this review suggest that patterns regarding the causational relationship between modifiable risk factors and CAD do not differ in terms of direction when compared across diverse ancestry populations. Differences in the observed strengths of the respective relationships however are indicative of the value of increasing representation in non-European populations, as novel genetic pathways or functional SNPs relating to CAD may be uncovered through a more global analysis.

SYSTEMATIC REVIEW REGISTRATION

The protocol for this systematic review was registered to the International Prospective Register of Systematic Reviews (PROSPERO) and is publicly available online (CRD42021272726).

Low-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol and apolipoprotein B for cardiovascular care

PURPOSE OF REVIEW

Some experts and consensus groups continue to argue that apolipoprotein B (apoB) should not be introduced broadly into clinical care. But, too often, the present approach to clinical care is not succeeding. An important reason for this failure, we believe, is that the conventional approach limits what the expert clinician can accomplish and is too complex, confusing, and contradictory for primary care physicians to apply effectively in their practise.

RECENT FINDINGS

There are four major reasons that apoB should be measured routinely in clinical care. First, apoB is a more accurate marker of cardiovascular risk than LDL-C or non-HDL-C. Second, the measurement of apoB is standardized whereas the measurements of LDL-C and non-HDL-C are not. Third, with apoB and a conventional lipid panel, all the lipid phenotypes can be simply and accurately distinguished. This will improve the care of the expert. Fourth, apoB, as the single measure to evaluate the success of therapy, would simplify the process of care for primary care physicians.

SUMMARY

By introducing apoB broadly into clinical care, the process of care will be improved for both the expert and the primary care physician, and this will improve the outcomes of care.

The Influence of Dietary Counseling Over 20 Years on Tracking of Non-High-Density Lipoprotein Cholesterol from Infancy to Young Adulthood

This 26-year study found that non-high-density lipoprotein cholesterol (non-HDL-C) levels tracked from infancy to young adulthood suggesting early-life non-HDL-C could predict future levels. However, infancy-onset dietary counseling reduced the odds of maintaining at-risk non-HDL-C, highlighting the potential importance of early interventions in preventing cardiovascular risk associated with high pediatric non-HDL-C.

Triglyceride-rich lipoprotein remnants, low-density lipoproteins, and risk of coronary heart disease: a UK Biobank study

AIMS

The strength of the relationship of triglyceride-rich lipoproteins (TRL) with risk of coronary heart disease (CHD) compared with low-density lipoprotein (LDL) is yet to be resolved.

METHODS AND RESULTS

Single-nucleotide polymorphisms (SNPs) associated with TRL/remnant cholesterol (TRL/remnant-C) and LDL cholesterol (LDL-C) were identified in the UK Biobank population. In a multivariable Mendelian randomization analysis, TRL/remnant-C was strongly and independently associated with CHD in a model adjusted for apolipoprotein B (apoB). Likewise, in a multivariable model, TRL/remnant-C and LDL-C also exhibited independent associations with CHD with odds ratios per 1 mmol/L higher cholesterol of 2.59 [95% confidence interval (CI): 1.99-3.36] and 1.37 [95% CI: 1.27-1.48], respectively. To examine the per-particle atherogenicity of TRL/remnants and LDL, SNPs were categorized into two clusters with differing effects on TRL/remnant-C and LDL-C. Cluster 1 contained SNPs in genes related to receptor-mediated lipoprotein removal that affected LDL-C more than TRL/remnant-C, whereas cluster 2 contained SNPs in genes related to lipolysis that had a much greater effect on TRL/remnant-C. The CHD odds ratio per standard deviation (Sd) higher apoB for cluster 2 (with the higher TRL/remnant to LDL ratio) was 1.76 (95% CI: 1.58-1.96), which was significantly greater than the CHD odds ratio per Sd higher apoB in cluster 1 [1.33 (95% CI: 1.26-1.40)]. A concordant result was obtained by using polygenic scores for each cluster to relate apoB to CHD risk.

CONCLUSION

Distinct SNP clusters appear to impact differentially on remnant particles and LDL. Our findings are consistent with TRL/remnants having a substantially greater atherogenicity per particle than LDL.

Standardization of Apolipoprotein B, LDL-Cholesterol, and Non-HDL-Cholesterol

Concern continues about whether the measurement of apolipoprotein B (apoB) is adequately standardized, and therefore, whether apoB should be applied widely in clinical care. This concern is misplaced. Our objective is to explain why and what the term "standardization" means. To produce clinically valid results, a test must accurately, precisely, and selectively measure the marker of interest. That is, it must be standardized. Accuracy refers to how closely the result obtained with 1 method corresponds to the result obtained with the standard method, precision to how reproducible the result is on repeated testing, and selectivity to how susceptible the method is to error by inclusion of other classes of lipoprotein particles. Multiple expert groups have determined that the measurement of apoB is adequately standardized for clinical care, and that apoB can be measured inexpensively, using widely available automated methods, more accurately, precisely, and selectively than low-density lipoprotein cholesterol or non-high-density lipoprotein cholesterol. ApoB is a standard superior to low-density lipoprotein cholesterol and high-density lipoprotein cholesterol because it is a defined molecule, whereas the cholesterol markers are the mass of cholesterol within lipoprotein particles defined by their density, not by their molecular structure. Nevertheless, the standardization of apoB is being further improved by the application of mass spectrophotometric methods, whereas the limitations in the standardization and, therefore, the accurate, precise, and selective measurement of low-density lipoprotein cholesterol and high-density lipoprotein cholesterol are unlikely to be overcome. We submit that greater accuracy, precision, and selectivity in measurement is a decisive advantage for apoB in the modern era of intensive lipid-lowering therapies.

Plant-Based Nutrition: Exploring Health Benefits for Atherosclerosis, Chronic Diseases, and Metabolic Syndrome-A Comprehensive Review

Atherosclerosis, chronic non-communicable diseases, and metabolic syndrome are highly interconnected and collectively contribute to global health concerns that reduce life expectancy and quality of life. These conditions arise from multiple risk factors, including inflammation, insulin resistance, impaired blood lipid profile, endothelial dysfunction, and increased cardiovascular risk. Adopting a plant-based diet has gained popularity as a viable alternative to promote health and mitigate the incidence of, and risk factors associated with, these three health conditions. Understanding the potential benefits of a plant-based diet for human health is crucial, particularly in the face of the rising prevalence of chronic diseases like diabetes, hypertension, dyslipidemia, atherosclerosis, and cancer. Thus, this review focused on the plausible advantages of consuming a type of food pattern for the prevention and/or treatment of chronic diseases, emphasizing the dietary aspects that contribute to these conditions and the evidence supporting the benefits of a plant-based diet for human health. To facilitate a more in-depth analysis, we present separate evidence for each of these three concepts, acknowledging their intrinsic connection while providing a specific focus on each one. This review underscores the potential of a plant-based diet to target the underlying causes of these chronic diseases and enhance health outcomes for individuals and populations.

Is hypertriglyceridemia a reliable indicator of cholesterol-depleted Apo B particles?

OBJECTIVES

Because cholesterol-depleted Apo B particles are thought to be a hallmark of hypertriglyceridemia, American, Canadian and European Lipid Guidelines suggest screening for Apo B only in patients with hypertriglyceridemia. Accordingly, this study examines the relationship of triglycerides to the LDL-C/Apo B and non-HDL-C/Apo B ratios.

METHODS

The study cohort consisted of 6272 NHANES subjects adjusted for a weighted sample size of 150 million subjects without previously diagnosed cardiac disease. Data was reported by LDL-C/Apo B tertiles as weighted frequencies and percent. Sensitivity, specificity, negative predictive and positive predictive values were calculated for triglycerides thresholds of >150 mg/dL and >200 mg/dL. The range of values of Apo B for decisional levels of LDL-C and non-HDL-C were also determined RESULTS: Among patients with triglycerides >200 mg/dL, 75.9% were amongst the lowest LDL-C/Apo B tertile. However, this represents only 7.5% of the total population. Of patients with the lowest LDL-C/Apo B ratio, 59.8% had triglycerides <150 mg/dL. Moreover, there was an inverse relationship between non-HDL-C/Apo B such that elevated triglycerides were associated with the highest tertile of non-HDL-C/Apo B. Finally, the range of values of Apo B for decisional levels of LDL-C and non-HDL-C was determined and is so broad- 30.3-40.6 mg/dl Apo B for different levels of LDL-C and 19.5 to 27.6 mg/dl Apo B for different levels of non-HDL-C- that neither is an adequate clinical surrogate for Apo B.

CONCLUSION

Plasma triglycerides should not be used to restrict the measurement of Apo B since cholesterol-depleted Apo B particles may be present at any level of triglyceride.

Apolipoprotein Particle and Cardiovascular Risk Prediction (from a Prospective Cohort Study)

The present study aimed to examine the association between discordant apolipoprotein B (Apo B) with low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (non-HDL-C) and cardiovascular disease (CVD) risk in the Chinese population and to determine whether adding information on Apo B to LDL-C and HDL-C improves CVD risk prediction. This study collected data from the China Health and Nutrition Survey from 2009 to 2015. Discordant Apo B with LDL-C and non-HDL-C were defined based on residual differences and medians. Logistic regression was used to examine the association between discordant Apo B with LDL-C or non-HDL-C and CVD risk. Areas under the receiver operating characteristic curve and categorical net reclassification improvement were utilized to assess the incremental predictive value of Apo B levels for CVD risk. A total of 7,117 participants were included, the mean age was 50.8 ± 14.3 years, 53.6% were female. During the 6-year follow-up, 207 CVD cases were identified. Participants with discordant high Apo B relative to LDL-C or non-HDL-C were at higher risk of CVD than those with the concordant group (odds ratio 1.38, 95% confidence interval 1.01 to 1.87; odds ratio 1.40, 95% confidence interval 1.01 to 1.94, respectively). However, Apo B had no significant contribution to the predictive value of the China atherosclerotic CVD (ASCVD) risk score (areas under the receiver operating characteristic curve 0.788 for China ASCVD score alone vs 0.790 for China ASCVD score plus Apo B). In conclusion, Apo B has the strongest association with CVD risk in healthy Chinese participants than LDL-C and non-HDL-C. However, it has minimal value in CVD risk assessment and discrimination.