Cardiovascular risk in patients achieving low-density lipoprotein cholesterol and particle targets

Current perspectives in obesity management: unraveling the impact of different therapy approach in real life obesity care

BACKGROUND

The challenge of addressing obesity persists in healthcare, necessitating nuanced approaches and personalized strategies. This study aims to evaluate the effects of diverse therapeutic interventions on anthropometric and biochemical parameters in individuals with overweight and obesity within a real-world clinical context.

METHODS

A retrospective analysis was conducted on 192 patients (141 females, 51 males) aged 18 to 75, with a BMI ranging from 25 to 30 (14.1%) and BMI ≥ 30 (85.9%), observed over a 12-month period at our Endocrinology Unit. Treatment cohorts comprised individuals following different regimens: Mediterranean Diet (MD), with an approximate daily intake of 1500 kcal for women and 1800 kcal for men (71% patients); Ketogenic Diet (KD), utilizing the VLCKD protocol characterized by a highly hypocaloric dietary regimen < 800 kcal/day (14% patients); metformin, administered using the oral formulation (5% patients); pharmacological intervention with GLP1-RA administered via subcutaneous injection with incremental dosage (10% patients). Supply constraints limited the efficacy of Liraglutide, whereas Semaglutide was excluded from comparisons due to its unavailability for obesity without diabetes. Blood tests were conducted to assess lipid profile, glycemic profile, and anthropometric parameters, including BMI, waist circumference, and waist-to-height ratio.

RESULTS

Significant BMI changes were observed from baseline to 6 months across MD, KD, and Liraglutide groups (p < 0.05). KD exhibited notable reductions in waist circumference and waist-to-height ratio within the initial quarter (p < 0.05), with a significant triglyceride decrease after 6 months (p < 0.05), indicating its efficacy over MD. Liraglutide demonstrated a substantial reduction in HbA1c levels in the first quarter (p < 0.05). During the first three months, the ANOVA test on fasting blood glucose showed a statistically significant impact of the time variable (p < 0.05) rather than the specific treatments themselves (Liraglutide and KD), suggesting that adherence during the early stages of therapy may be more critical than treatment choice.

CONCLUSIONS

Positive outcomes from targeted interventions, whether pharmacological or dietary should encourage the exploration of innovative, long-term strategies that include personalized treatment alternation. The absence of standardized protocols underscores the importance of careful and tailored planning in managing obesity as a chronic condition.

Use of lipid ratios to predict vascular target organ damage in youth

BACKGROUND

Elevated lipid levels are risk factors for early atherosclerosis. Lipid ratios have emerged as potentially stronger predictors of adverse cardiovascular changes and atherogenic cholesterol. Risk stratification in youth with obesity or type 2 diabetes may be improved by using lipid ratios. We sought to determine if lipid ratios would identify abnormalities in arterial structure and stiffness in adolescents and young adults.

METHODS

A total of 762 youth aged 10-24 years had laboratory, anthropometric, blood pressure, and carotid intima-media thickness and arterial stiffness data collected. Subjects were stratified into tertiles (low, mid, high) of lipid ratios and non-high-density lipoprotein cholesterol (HDL-C). Vascular outcomes by tertile were assessed by analyses of variance. General linear models were constructed for each lipid value and included demographics, risk factors and vascular measures. Correlations between lipid markers, vascular measures, and low-density lipoprotein (LDL) particle size and number were conducted.

RESULTS

There was a progressive increase in arterial thickness and stiffness across all three lipid ratios and non-HDL-C. The triglyceride to HDL-C (TG/HDL-C) ratio remained an independent predictor of arterial thickness and stiffness after adjusting for other cardiovascular risk factors. TG/HDL-C had the highest correlations with arterial stiffness and small, dense LDL.

CONCLUSIONS

Arterial stiffness is increased in youth with high lipid ratios with TG/HDL-C being the most consistent marker of vascular changes. These data suggest that identification of high TG/HDL-C in these individuals may lead to earlier intervention to prevent atherosclerotic cardiovascular disease.

Lipoproteins and Their Effects on the Cardiovascular System

Coronary heart disease is the foremost leading cause of death across the world. It mainly involves the blood vessels, which supply the heart. Plaque formation due to lipid deposition leads to the narrowing of the vessels, obstructing blood flow. Therefore, lipoproteins such as high-density lipoproteins (HDL), low-density lipoproteins (LDL), very low-density lipoproteins (VLDL), and chylomicrons play a crucial role in cardiovascular diseases. Lipoproteins are carrier molecules made up of proteins and fats. They carry cholesterol through the bloodstream and transport it to the peripheral tissues or the liver. There are several classes of lipoproteins in the blood, namely HDL, LDL, VLDL, and chylomicrons. Depending on the lipoproteins, an excess of them can either harm or benefit the body. Low-density lipoprotein, nicknamed 'the bad cholesterol,' transports fatty molecules from the liver and deposits them in peripheral tissues or central vessels. Thus, excess LDL can cause blockage of the arteries supplying major organs. High-density lipoprotein, nicknamed 'the good cholesterol,' transports the excess fatty molecules to the liver for their metabolism and removal from the body. Hence, high levels of HDL are an indication of a healthy body. Thus, lipoproteins are important molecules, and their proper regulation is essential to maintaining a healthy body. An effective way to maintain a balanced lipoprotein level is to have a properly balanced diet with high protein and low fat. Regular exercise, both indoors and outdoors, is recommended. If cholesterol levels are not maintained by diet and exercise, medication is advised after consulting medical experts. This review aims to inform people about lipoproteins, their importance, and maintaining a healthy lipoprotein level.

Insulin resistance in Alzheimer's disease: The genetics and metabolomics links

Alzheimer's disease (AD) is a neurodegenerative disease with significant socioeconomic burden worldwide. Although genetics and environmental factors play a role, AD is highly associated with insulin resistance (IR) disorders such as metabolic syndrome (MS), obesity, and type two diabetes mellitus (T2DM). These findings highlight a shared pathogenesis. The use of metabolomics as a downstream systems' biology (omics) approach can help to identify these shared metabolic traits and assist in the early identification of at-risk groups and potentially guide therapy. Targeting the shared AD-IR metabolic trait with lifestyle interventions and pharmacological treatments may offer promising AD therapeutic approach. In this narrative review, we reviewed the literature on the AD-IR pathogenic link, the shared genetics and metabolomics biomarkers between AD and IR disorders, as well as the lifestyle interventions and pharmacological treatments which target this pathogenic link.

1H-magnetic resonance spectroscopy lipoprotein profile in patients with chronic heart failure versus matched controls

INTRODUCTION AND OBJECTIVES

Advanced lipoprotein phenotyping is a better predictor of atherosclerotic cardiovascular risk than cholesterol concentration alone. Lipoprotein profiling in heart failure (HF) is incompletely characterized. We aimed to describe the lipoprotein profile in patients with chronic HF compared with a matched control population.

METHODS

This cross-sectional study was performed from May 2006 to April 2014 and included ambulatory patients with chronic HF. Lipid concentrations and the size of main lipoprotein fractions (high-density lipoprotein [HDL], low-density lipoprotein [LDL], and very low-density lipoprotein) and the particle concentration of their 3 subfractions (large, medium and small) were assessed using 1H magnetic resonance spectroscopy.

RESULTS

The 429 included patients with chronic HF were compared with 428 matched controls. Patients with chronic HF had lower total cholesterol and lower mean LDL (1115 vs 1352 nmol/L; P<.001) and HDL (25.7 vs 27.9μmol/L; P <.001) particle concentrations, with this last difference being mediated by a significantly lower concentration of the small subfraction of HDL (15.2 vs 18.6μmol/L; P <.001). Mean very low-density lipoprotein, LDL, and HDL particle size was significantly higher in patients with HF vs controls. All HDL-related differences from controls persisted after adjustment for New York Heart Association functional class or body mass index. We found strong negative correlations of known cardiac biomarkers (N-terminal pro-brain natriuretic peptide and interleukin-1 receptor-like 1) with total and small LDL and HDL fractions and HDL particle size.

CONCLUSIONS

Patients with chronic HF significantly differ in their lipoprotein profile compared with unaffected controls. Further research is needed to better understand the pathogenic relevance of this difference.

Integrating Advanced Lipid Testing and Biomarkers in Assessment and Treatment

PURPOSE OF REVIEW

Our ability to assess and stratify atherosclerotic disease risk in patients is evolving. Recent advances in advanced lipid testing have created opportunities for clinical application of novel biomarkers.

RECENT FINDINGS

Until recently, LDL-C has served largely as the singular biomarker of ASCVD and guide for decisions in treatment for high-risk groups. There are important evolutions in the measurement of LDL-C but even still, the pathogenesis of atherosclerosis and ASCVD is not solely driven by LDL-C. As atherosclerosis is driven by multiple complex pathways including inflammation, it is important to expand our focus beyond LDL-C and utilize multiple biomarkers in the assessment of this disease process. Non-HDL, ApoB, LDL-P, Lp(a), and hsCRP are unique tools to aid in cardiac risk evaluation, especially in higher risk patients, though not limited to this population. A multifaceted approach to advanced lipid testing with novel biomarkers will enhance comprehensive ASCVD risk assessments.

Lipoprofiling Assessed by NMR Spectroscopy in Patients with Acute Coronary Syndromes: Is There a Need for Fasting Prior to Sampling?

Most patients presenting in an emergency unit with acute coronary syndromes (ACS) (which include non-ST-elevation myocardial infarction (NSTEMI), ST-elevation MI (STEMI), and unstable angina) usually meet at least two cardiovascular risk factors, such as dyslipidemia, arterial hypertension, diabetes mellitus type 2, obesity, history of or current smoking, etc. Most ACS patients suffer from a type of dyslipidemia, and in addition to this there are ACS patients rushed into the emergency units for which the feeding status is unknown. Thus, we set out to evaluate the effect of fasting on 16 blood metabolite concentrations and 114 lipoprotein parameters on one control group and a group of statin-treated ACS patients hospitalized in a cardiovascular emergency unit, using Nuclear Magnetic Resonance (NMR) spectroscopy. The results indicated trends (in terms of number of cases, but not necessarily in terms of the magnitude of the effect) for as many as four metabolites and 48 lipoproteins. The effect was defined as a trend for results showing over 70% of the cases from either one or both groups that experienced parameter changes in the same direction (i.e., either increased or decreased). In terms of magnitude, the effect is rather low, leading to the overall conclusion that in cardiovascular (CV) emergency units, the blood samples analyzed in any feeding status would provide close results and very valuable information regarding prognosis and for fast decisions on patient’s proper management.

Lipid Testing Trends Before and After Hospitalization for Myocardial Infarction Among Adults in the United States, 2008-2019

Background

Routine monitoring of low-density lipoprotein cholesterol (LDL-C) identifies patients who may benefit from modifying lipid-lowering therapies (LLT). However, the extent to which LDL-C testing is occurring in clinical practice is unclear, specifically among patients hospitalized for a myocardial infarction (MI).

Methods

Using US commercial claims data, we identified patients with an incident MI hospitalization between 01/01/2008-03/31/2019. LDL-C testing was assessed in the year before admission (pre-MI) and the year after discharge (post-MI). Changes in LDL-C testing were evaluated using a Poisson model fit to pre-MI rates and extrapolated to the post-MI period. We predicted LDL-C testing rates if no MI had occurred (ie, based on pre-MI trends) and estimated rate differences and ratios (contrasting observed vs predicted rates).

Results

Overall, 389,367 patients were hospitalized for their first MI during the study period. In the month following discharge, 9% received LDL-C testing, increasing to 27% at 3 months and 52% at 12 months. Mean rates (tests per 1000 patients per month) in the pre- and post-MI periods were 51.9 (95% CI: 51.7, 52.1) and 84.4 (95% CI: 84.1, 84.6), respectively. Over 12 months post-MI, observed rates were higher than predicted rates; the maximum rate difference was 66 tests per 1000 patients in month 2 (rate ratio 2.2), stabilizing at a difference of 15-20 (ratio 1.2-1.3) for months 6-12.

Conclusion

Although LDL-C testing increased following MI hospitalization, rates remained lower than recommended by clinical guidelines. This highlights a potential gap in care, where increased LDL-C testing after MI may provide opportunities for LLT modification and decrease risk of subsequent cardiovascular events.

Biomarker Discovery in Atherosclerotic Diseases Using Quantitative Nuclear Magnetic Resonance Metabolomics

Despite great progress in the management of atherosclerosis (AS), its subsequent cardiovascular disease (CVD) remains the leading cause of morbidity and mortality. This is probably due to insufficient risk detection using routine lipid testing; thus, there is a need for more effective approaches relying on new biomarkers. Quantitative nuclear magnetic resonance (qNMR) metabolomics is able to phenotype holistic metabolic changes, with a unique advantage in regard to quantifying lipid-protein complexes. The rapidly increasing literature has indicated that qNMR-based lipoprotein particle number, particle size, lipid components, and some molecular metabolites can provide deeper insight into atherogenic diseases and could serve as novel promising determinants. Therefore, this article aims to offer an updated review of the qNMR biomarkers of AS and CVD found in epidemiological studies, with a special emphasis on lipoprotein-related parameters. As more researches are performed, we can envision more qNMR metabolite biomarkers being successfully translated into daily clinical practice to enhance the prevention, detection and intervention of atherosclerotic diseases.

Low-density lipoprotein cholesterol-to-apolipoprotein B ratio as a potential indicator of LDL particle size and plasma atherogenicity in type 2 diabetes

AIMS

Atherogenic dyslipidemia, associated with small, dense low-density lipoprotein-cholesterol (S-LDL) particles and impaired metabolism of triglycerides (TGs) and high-density lipoprotein-cholesterol (HDL-c), leads to the development of atherosclerosis-related complications of type 2 diabetes mellitus. Based on the hypothesis that an LDL-c-to-apolipoprotein B ratio (LDL/ApoB) < 1.2 may predict the prevalence of S-LDL, this study aimed to evaluate the LDL/ApoB ratio in patients with type 2 diabetes with moderately elevated TG levels.

METHODS

The study population consisted of 121 outpatients with type 2 diabetes (S-LDL group, LDL/ApoB < 1.2, n = 79; L-LDL group, LDL/ApoB > 1.2, n = 42) and 58 healthy subjects. The LDL/ApoB ratio was calculated from the measured LDL-c and ApoB levels in participants with TG levels lower than 4.5 mmol/L. Since TGs and HDL-c are included in the atherogenic index of plasma (AIP), we evaluated the relationship between LDL/ApoB and the AIP.

RESULTS

Higher levels of AIP, TG (both P < 0.0001), and lipid hydroperoxides (LOOH) (P < 0.001) and lower levels of HDL-c, total cholesterol, and non-HDL-c (P < 0.001, <0.01, <0.05, respectively) were found in the S-LDL group compared to the L-LDL group. There were significant relationships between the LDL/ApoB ratio and the AIP, TG (both P < 0.0001), LOOH (P < 0.0005), and HDL-c levels (P < 0.05) in the S-LDL group.

CONCLUSIONS

The prevalence of S-LDL particles (65%) and the close association of LDL/ApoB with the AIP suggest that this ratio may be a potential indicator of increased cardiovascular risk in patients with type 2 diabetes.

Effect of low-carbohydrate diets on cardiometabolic risk, insulin resistance, and metabolic syndrome

PURPOSE OF REVIEW

An obesity epidemic has resulted in increasing prevalence of insulin resistance, hyperinsulinemia, metabolic syndrome (MetS), and cardiovascular disease (CVD). The Diet-Heart Hypothesis posited that dietary fat is the culprit. Yet dietary fat reduction has contributed to the problem, not resolved it. The role of hyperinsulinemia, the genesis of its atherogenic dyslipidemia and systemic inflammation in CVD and its reversal is reviewed.

RECENT FINDINGS

Overnutrition leads to weight gain and carbohydrate intolerance creating a vicious cycle of insulin resistance/hyperinsulinemia inhibiting fat utilization and encouraging fat storage leading to an atherogenic dyslipidemia characterized by hypertriglyceridemia, low HDL, and small dense LDL. The carbohydrate-insulin model better accounts for the pathogenesis of obesity, MetS, and ultimately type 2 diabetes (T2DM) and CVD. Ketogenic Diets reduce visceral obesity, increase insulin sensitivity, reverse the atherogenic dyslipidemia and the inflammatory biomarkers of overnutrition. Recent trials show very high adherence to ketogenic diet for up to 2 years in individuals with T2DM, reversing their metabolic, inflammatory and dysglycemic biomarkers as well as the 10-year estimated atherosclerotic risk. Diabetes reversal occurred in over 50% and complete remission in nearly 8%.

SUMMARY

Therapeutic carbohydrate-restricted can prevent or reverse the components of MetS and T2DM.

Consensus document of an expert group from the Spanish Society of Arteriosclerosis (SEA) on the clinical use of nuclear magnetic resonance to assess lipoprotein metabolism (Liposcale®)

The assessment and prevention of cardiovascular risk (CVR) that persists in patients with dyslipidaemia despite treatment and achievement of goals specific to the plasma concentration of cholesterol linked to low density (c-LDL) is a clinical challenge today, and suggests that conventional lipid biomarkers are insufficient for an accurate assessment of CVR. Apart from their lipid content, there are other lipid particle characteristics. The results of this study show that there are a number of lipoprotein compounds that determine atherogenic potential and its influence on the CVR. However, such additional characteristics cannot be analysed by the techniques commonly used in clinical laboratories. Nuclear Magnetic Resonance (NMR) is a technique that allows a detailed analysis to be made of the amount, composition, and size of lipoproteins, as well as providing more information about the detailed status of lipid metabolism and CVR in dyslipidaemia patients. In this article a group of lipidologists from the Spanish Society of Arteriosclerosis review the existing evidence on the atherogenic mechanisms of particles and describe the technical basis and interpretation of the profiles lipoproteins obtained by MRI, with special reference to the test available in Spain (Liposcale®). Likewise, the main patient profiles are defined as such that an analysis would provide information of greater clinical interest. These include: a) Suspected mismatch between lipid concentrations and particles, a common situation in diabetes, obesity, metabolic syndrome; b) Early atherothrombotic cardiovascular disease (ECVA) or recurrent without CVR factors to justify it; c) Lipid disorders, rare or complex, such as extreme concentrations of c-HDL, and d) Clinical situations where classical analytical techniques cannot be applied, such as very low c-LDL values.

Precipitated sdLDL: An easy method to estimate LDL particle size

Background

LDL‐C lowering is the main measure in cardiovascular disease prevention but a residual risk of ischemic events still remains. Alterations of lipoproteins, specially, increase in small dense LDL (sdLDL) particles are related to this risk.

Objective

To investigate the potential use of sdLDL cholesterol concentration (sdLDL‐C) isolated by an easy precipitation method and to assess the impact of a set of clinical and biochemical variables determined by NMR on sdLDL concentration.

Methods

sdLDL‐C and NMR lipid profile were performed in 85 men samples. Association among them was evaluated using Pearson coefficients (r_xy). A multivariate regression was performed to identify the influence of NMR variables on sdLDL‐C.

Results

A strong association between sdLDL‐C and LDLLDL‐P (r_xy = 0.687) and with LDL‐Z (r_xy = −0.603) was found. The multivariate regression explained a 56.8% in sdLDL‐C variation (P = 8.77.10‐12). BMI, ApoB, triglycerides, FFA, and LDL‐Z showed a significant contribution. The most important ones were ApoB and LDL‐Z; a 1nm increase (LDL‐Z) leads to decrease 126 nmol/L in sdLDL‐C.

Conclusion

The association between sdLDL‐C, LDL‐Z, and LDL‐P is clear. From a large number of variables, especially LDL‐Z and apoB influence on sdLDL‐C. Results show that the smaller the LDL size, the higher their cholesterol concentration. Therefore, sdLDL‐C determination by using this easy method would be useful to risk stratification and to uncover cardiovascular residual risk.

The ketogenic diet: Pros and cons

Diets have been at the center of animated debates for decades and many claims have been made in one direction or the other by supporters of opposite camps, often with limited evidence. At times emphasis has been put on a single new aspect that the previous diets had overlooked and the new one was to embrace in order to improve weight loss and well-being. Unfortunately, very few randomized clinical trials involving diets have addressed the combined question of weight loss and cardiovascular outcomes. The recently introduced ketogenic diet requires a rigorous limitation of carbohydrates while allowing a liberal ingestion of fats (including saturated fats) and has generated a flurry of interest with many taking the pro position and as many taking the cons position. The ketogenic diet causes a rapid and sensible weight loss along with favourable biomarker changes, such as a reduction in serum hemoglobin A1c in patients with diabetes mellitus type 2. However, it also causes a substantial rise in low density lipoprotein cholesterol levels and many physicians are therefore hesitant to endorse it. In view of the popular uptake of the keto diet even among subjects not in need of weight loss, there is some preoccupation with the potential long-term consequences of a wide embrace of this diet by large segments of the population. On the contrary, numerous lines of evidence show that plant-based diets are associated with reduction in oncological and cardiovascular diseases and a prolonged life span. The debate reproduced in this article took place during a continuous medical education program between two cardiologists with largely differing views on the matter of effectiveness, sustainability, and safety of the ketogenic diet compared to alternative options.

Pharmacokinetics and exploratory efficacy biomarkers of bococizumab, an anti-PCSK9 monoclonal antibody, in hypercholesterolemic Japanese subjects

Objective: Bococizumab, a monoclonal antibody targeting proprotein convertase subtilisin/kexin type 9, has been shown to reduce low-density lipoprotein cholesterol (LDL-C). Here, we describe the pharmacokinetics and pharmacodynamics of bococizumab and its effect on lipoprotein particle composition and other biomarkers, based on a double-blind, placebo-controlled, randomized, dose-ranging study. Materials and methods: The study consisted of two populations: Japanese subjects with uncontrolled LDL-C (LDL-C ≥ 100 mg/dL) despite treatment with atorvastatin (n = 121) and Japanese subjects naïve to lipid-lowering agents with LDL-C ≥ 130 mg/dL (n = 97). Subjects were randomized to receive either bococizumab 50, 100, or 150 mg or placebo, every 2 weeks. One arm of subjects in the atorvastatin-treated population received ezetimibe 10 mg instead of bococizumab. Results: In both populations, bococizumab exposure increased with increasing dose, and subjects with lower body weights tended to have higher exposures. Bococizumab treatment was associated with a dose-dependent reduction in LDL particles and a small increase in total high-density lipoprotein (HDL) particles. Significant reductions in lipoprotein-associated phospholipase A2 (Lp-PLA2) were observed for bococizumab-treated subjects but not for subjects treated with placebo or ezetimibe. Conclusion: Increased bococizumab dosage resulted in increased exposure. Levels of LDL and HDL particles and biomarkers such as Lp-PLA2 were also altered with bococizumab treatment. (ClinicalTrials.gov identifier: NCT02055976).

Interdependence of oxidative/antioxidant system indicators and thyroid status under conditions of prolonged exposure to small doses of radiation

We have studied the interdependence of the intensity of oxidative processes/antioxidant level and the thyroid status parameters in a group of students aged 18–24 who lived for a long time in the territory of enhanced radioecological control (density of soil contamination by isotopes (137Cs 3.7 ∙ 104 – 18.5 ∙ 104 Bq/m2). We examined 50 people from relatively environmentally friendly areas (control group) and 50 people from IV radiation zone (experimental group). In the experimental group, there were no individuals with clinical manifestations of thyroid pathology. However, subgroups with signs of hyperthyroidism and hypothyroidism were identified. We evaluated the level of cortisol, thyrotrophic hormone (TSH), triiodothyronine (T3), thyroxine (T4), malonic dialdehyde (MDA), ceruloplasmin (CP), transferrin (Tf), sulfhydryl groups (SH); we calculated the oxidative stress index (OSI). The research was conducted one month before the examination time and also during the exams as a factor in increased emotional stress. A lowered CP level was found in the subgroup with signs of hypothyroidism; SH groups – in all subgroups, separated by thyroid status. The oxidative stress index was higher in all students examined of the experimental group, compared with the control. The growth of MDA level is marked in the experimental group – it is the most strongly pronounced in conditions of additional emotional load in people with signs of hyperthyroidism and hypothyroidism. CP level significantly decreased in the subgroup of hyperthyroidism on the background of T3 decrease. OSI increased in all students examined from the experimental group. In the subgroup of hypothyroidism it became significantly higher than in the subgroup of euthyroidism. A positive correlation between the levels of CP and T3 was found. The highest values of the correlation coefficients were noted for subgroups with signs of hyperthyroidism and hypothyroidism, with the coefficient significance increasing under conditions of emotional stress. The index of oxidative stress in the experimental group positively correlated with the level of TSH – in terms of emotional stress, the statistical significance of the coefficients disappeared. In the subgroups divided by thyroid status, variability of interactions between OSI and T3 was observed but it was not statistically significant. It was found that the participation of thyroid status in supporting redox homeostasis in people aged 18–24 who suffered from chronic small-doze radiation exposure was realized mainly by the influence on the antioxidant system. The ability of thyroid hormones to maintain a proper antioxidant state was suppressed in this group. The unbalanced relationship between thyroid hormones and oxidative stress indicators is strongly manifested under conditions of additional emotional stress.

Effects of Evolocumab on the ApoA1 Remnant Ratio: A Pooled Analysis of Phase 3 Studies

Introduction

The apolipoprotein A1 (apoA1) remnant ratio has been identified as an independent cardiovascular (CV) risk factor. Higher apoA1 remnant ratios may predict lower CV risk in some patients. This analysis aimed to evaluate the effects of evolocumab on the change from baseline in the apoA1 remnant ratio compared with placebo.

Methods

This pooled post hoc analysis included 2464 patients with mixed dyslipidemia treated with evolocumab 140 mg every 2 weeks (Q2W) or 420 mg once monthly (QM) in three phase 3 evolocumab trials. The apoA1 remnant ratio was calculated by dividing apoA1 by the difference between non-high-density lipoprotein cholesterol (non-HDL-C) and low-density lipoprotein cholesterol (LDL-C). ApoA1 remnant ratio strata were generated using previously published tertile (< 4.7, 4.7–6.8, and > 6.8) and partitioning categories (< 3.6, 3.6–6.0, and > 6.0).

Results

The baseline apoA1 remnant ratio in evolocumab and placebo treatment arms was 7.1 and 7.3, respectively. At week 12, evolocumab 140 mg Q2W and 420 mg QM increased the apoA1 remnant ratio by 25.0% and 33.6%, respectively, versus placebo (p < 0.0001 for both groups). When patients were categorized by week 12 apoA1 remnant ratio thresholds (< 3.6 vs. > 3.6, and < 4.7 vs. > 4.7), those with higher week 12 apoA1 remnant ratios were significantly more likely to have also achieved a target non-HDL-C level of < 100 mg/dl. In the subset of women > 50 years of age, the proportion of patients at apoA1 remnant ratio thresholds < 3.6, 3.6–6.0, and > 6.0 at baseline shifted toward or remained at higher thresholds at week 12.

Conclusions

This post hoc analysis suggests that evolocumab increases the apoA1 remnant ratio.

Funding

Amgen Inc.

Plain Language Summary

Plain language summary available for this article.

Electronic supplementary material

The online version of this article (10.1007/s40119-019-0133-6) contains supplementary material, which is available to authorized users.

Bread enriched with phytosterols with or without curcumin modulates lipoprotein profiles in hypercholesterolaemic individuals. A randomised controlled trial

A novel functional food containing phytosterols and curcumin significantly lowers blood cholesterol concentrations in hypercholesterolaemic individuals.

Development of novel aptamers for low-density lipoprotein particle quantification

Cardiovascular disease (CVD) remains the leading cause of death worldwide. Low-density lipoprotein cholesterol (LDL-C) is commonly used for CVD risk assessment; however, recent research has shown LDL particle (LDL-P) number to be a more sensitive indicator of CVD risk than both LDL-C and non-high-density lipoprotein cholesterol (HDL-C). Described herein are five single stranded DNA aptamers with dissociation constants in the low picomolar range specific to LDL-P and its subfractions. Furthermore, a set of antisense sequences have been developed and characterized that are capable of binding to the best aptamers and undergoing displacement by LDL-P for use in a simple, affordable diagnostic assay.

Lipids and Lipoproteins in Risk Prediction

Ischemic heart disease remains the leading cause of death worldwide. Low-density lipoprotein cholesterol (LDL-C) has proved to have a causal relationship with atherosclerotic cardiovascular disease. Lowering LDL-C improves outcomes, although some patients continue to have residual risk of cardiovascular disease. Cardiovascular risk prediction calculators are routinely used in to identify patients most at risk. Research into other lipoprotein factors has suggested that they may have advantages over LDL-C and improve the ability to identify those most at risk. Although some technology is not widely available, there is potential for better risk prediction in specific groups.

Cardiovascular disease risk factor responses to a type 2 diabetes care model including nutritional ketosis induced by sustained carbohydrate restriction at 1 year: an open label, non-randomized, controlled study

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of death among adults with type 2 diabetes mellitus (T2D). We recently reported that glycemic control in patients with T2D can be significantly improved through a continuous care intervention (CCI) including nutritional ketosis. The purpose of this study was to examine CVD risk factors in this cohort.

METHODS

We investigated CVD risk factors in patients with T2D who participated in a 1 year open label, non-randomized, controlled study. The CCI group (n = 262) received treatment from a health coach and medical provider. A usual care (UC) group (n = 87) was independently recruited to track customary T2D progression. Circulating biomarkers of cholesterol metabolism and inflammation, blood pressure (BP), carotid intima media thickness (cIMT), multi-factorial risk scores and medication use were examined. A significance level of P < 0.0019 ensured two-tailed significance at the 5% level when Bonferroni adjusted for multiple comparisons.

RESULTS

The CCI group consisted of 262 participants (baseline mean (SD): age 54 (8) year, BMI 40.4 (8.8) kg m-2). Intention-to-treat analysis (% change) revealed the following at 1-year: total LDL-particles (LDL-P) (- 4.9%, P = 0.02), small LDL-P (- 20.8%, P = 1.2 × 10-12), LDL-P size (+ 1.1%, P = 6.0 × 10-10), ApoB (- 1.6%, P = 0.37), ApoA1 (+ 9.8%, P < 10-16), ApoB/ApoA1 ratio (- 9.5%, P = 1.9 × 10-7), triglyceride/HDL-C ratio (- 29.1%, P < 10-16), large VLDL-P (- 38.9%, P = 4.2 × 10-15), and LDL-C (+ 9.9%, P = 4.9 × 10-5). Additional effects were reductions in blood pressure, high sensitivity C-reactive protein, and white blood cell count (all P < 1 × 10-7) while cIMT was unchanged. The 10-year atherosclerotic cardiovascular disease (ASCVD) risk score decreased - 11.9% (P = 4.9 × 10-5). Antihypertensive medication use was discontinued in 11.4% of CCI participants (P = 5.3 × 10-5). The UC group of 87 participants [baseline mean (SD): age 52 (10) year, BMI 36.7 (7.2) kg m-2] showed no significant changes. After adjusting for baseline differences when comparing CCI and UC groups, significant improvements for the CCI group included small LDL-P, ApoA1, triglyceride/HDL-C ratio, HDL-C, hsCRP, and LP-IR score in addition to other biomarkers that were previously reported. The CCI group showed a greater rise in LDL-C.

CONCLUSIONS

A continuous care treatment including nutritional ketosis in patients with T2D improved most biomarkers of CVD risk after 1 year. The increase in LDL-cholesterol appeared limited to the large LDL subfraction. LDL particle size increased, total LDL-P and ApoB were unchanged, and inflammation and blood pressure decreased. Trial registration Clinicaltrials.gov: NCT02519309. Registered 10 August 2015.

Residual atherosclerotic cardiovascular disease risk in statin-treated adults: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Residual atherosclerotic cardiovascular disease (ASCVD) risk in statin-treated US adults without known ASCVD is not well described.

OBJECTIVE

To quantitate residual ASCVD risk and its predictors in statin-treated adults.

METHODS

We studied 1014 statin-treated adults (53.3% female, mean 66.0 years) free of clinical ASCVD in the Multi-Ethnic Study of Atherosclerosis. We examined ASCVD event rates by National Lipid Association risk groups over 11-year follow-up and the relation of standard risk factors, biomarkers, and subclinical atherosclerosis measures with residual ASCVD event risk.

RESULTS

Overall, 5.3% of participants were at low, 12.2% at moderate, 60.3% at high, and 22.2% at very high baseline risk. Despite statin therapy, age- and race-standardized ASCVD rates per 1000 person-years for men and women were both 4.9 for low/moderate risk, 19.1 and 14.2 for high risk, and 35.6 and 26.7 for very high risk, respectively. Specific independent predictors of residual risk included current smoking, family history, diabetes, high-sensitivity C-reactive protein, low-density lipoprotein particle number, carotid intimal medial thickness, and especially coronary artery calcium score. Those on moderate- or high-intensity statins at baseline (compared with low intensity) had 39% lower risks and those who increased statin intensity 62% lower ASCVD event risks (P < .01).

CONCLUSION

Residual risk of ASCVD remains high despite statin treatment and is predicted by specific risk factors and subclinical atherosclerosis. These findings may be helpful for identifying those at highest risk needing more aggressive treatment.

Cost Effectiveness of Achieving Targets of Low-Density Lipoprotein Particle Number Versus Low-Density Lipoprotein Cholesterol Level

A recent analysis of a commercially insured US population found fewer cardiovascular disease (CVD) events in high-risk patients attaining low levels of low-density lipoprotein (LDL), as measured by LDL particle number (LDL-P) versus low LDL cholesterol (LDL-C). Here, we investigated the cost effectiveness of LDL-lowering therapy guided by LDL-P. Patients were selected from the HealthCore Integrated Research Database and followed for 12 to 36 months. Patients who achieved LDL-P <1,000 nmol/l were placed into the LDL-P cohort, whereas those without LDL-P tests, but who achieved LDL-C <100 mg/dl, were placed into the LDL-C cohort. CVD-related costs included all health plan paid amounts related to CVD events or lipid management. Cost effectiveness was assessed through incremental cost-effectiveness ratios, defined as difference in total costs across the cohorts divided by difference in CVD events, measured over follow-up. Each cohort included 2,094, 1,242, and 705 patients over 12-, 24-, and 36-month follow-up. Patients in the LDL-P cohort received more aggressive lipid-lowering therapy and had fewer CVD events during follow-up compared to patients in the LDL-C cohort. This led to greater pharmacy costs and lower medical costs over time. Incremental cost-effectiveness ratio estimates ranged from $23,131 per CVD event avoided at 12 months to $3,439 and -$4,555 at 24- and 36-month follow-up, suggesting a high likelihood that achieving LDL-P <1,000 nmol/l is cost effective. In conclusion, LDL-lowering therapy guided by LDL-P was demonstrated to be cost effective, with greater clinical and economic benefit seen over longer time horizons and with the increased use of generic statins.

National Lipid Association Annual Summary of Clinical Lipidology 2016

The National Lipid Association (NLA) Annual Summary of Clinical Lipidology is a yearly updated summary of principles important to the patient-centered evaluation, management, and care of patients with dyslipidemia. This summary is intended to be a "living document," with future annual updates based on emerging science, clinical considerations, and new NLA Position, Consensus, and Scientific Statements, thus providing an ongoing resource that applies the latest in medical science towards the clinical management of patients with dyslipidemia. Topics include the NLA Recommendations for Patient-Centered Management of Dyslipidemia, genetics, Familial Hypercholesterolemia, secondary causes of dyslipidemia, biomarkers and advanced lipid testing, nutrition, physical activity, obesity, adiposopathy, metabolic syndrome, diabetes mellitus, lipid pharmacotherapy, lipid-altering drug interactions, lipoprotein apheresis, dyslipidemia management and treatment based upon age (children, adolescents, and older individuals), dyslipidemia considerations based upon race, ethnicity and gender, dyslipidemia and human immune virus infection, dyslipidemia and immune disorders, adherence strategies and collaborative care, and lipid-altering drugs in development. Hyperlinks direct the reader to sentinel online tables, charts, and figures relevant to lipidology, access to online atherosclerotic cardiovascular disease risk calculators, worldwide lipid guidelines, recommendations, and position/scientific statements, as well as links to online audio files, websites, slide shows, applications, continuing medical education opportunities, and patient information.

Hepatitis C virus G1b infection decreases the number of small low-density lipoprotein particles

AIM: To investigate how hepatitis C virus (HCV) G1b infection influences the particle number of lipoproteins.

METHODS: The numbers of lipoprotein particles in fasting sera from 173 Japanese subjects, 82 with active HCV G1b infection (active HCV group) and 91 with cleared HCV infection (SVR group), were examined. Serum lipoprotein was fractionated by high-performance liquid chromatography into twenty fractions. The cholesterol and triglyceride concentrations in each fraction were measured using LipoSEARCH. The number of lipoprotein particles in each fraction was calculated using a newly developed algorithm, and the relationship between chronic HCV G1b infection and the lipoprotein particle number was determined by multiple linear regression analysis.

RESULTS: The median number of low-density lipoprotein (LDL) particles was significantly lower in the active HCV group [1182 nmol/L, interquartile range (IQR): 444 nmol/L] than in the SVR group (1363 nmol/L, IQR: 472 nmol/L, P < 0.001), as was that of high-density lipoprotein (HDL) particles (14168 nmol/L vs 15054 nmol/L, IQR: 4114 nmol/L vs 3385 nmol/L, P = 0.042). The number of very low-density lipoprotein (VLDL) particles was similar between the two groups. Among the four LDL sub-fractions, the number of large LDL particles was similar between the two groups. However, the numbers of medium (median: 533.0 nmol/L, IQR: 214.7 nmol/L vs median: 633.5 nmol/L, IQR: 229.6 nmol/L, P < 0.001), small (median: 190.9 nmol/L, IQR: 152.4 nmol/L vs median: 263.2 nmol/L, IQR: 159.9 nmol/L; P < 0.001), and very small LDL particles (median: 103.5 nmol/L, IQR: 66.8 nmol/L vs median: 139.3 nmol/L, IQR: 67.3 nmol/L, P < 0.001) were significantly lower in the active HCV group than in the SVR group, respectively. Multiple linear regression analysis indicated an association between HCV G1b infection and the decreased numbers of medium, small, and very small LDL particles. However, active HCV infection did not affect the number of large LDL particles or any sub-fractions of VLDL and HDL particles.

CONCLUSION: HCV G1b infection decreases the numbers of medium, small, and very small LDL particles.

Meta-analysis of risk factors associated with atherosclerosis in patients with Kawasaki disease

BACKGROUND

Kawasaki disease (KD) has now become the leading cause of acquired heart disease among children in developed countries. This study investigated whether patients with KD have an increased risk of atherosclerosis.

METHODS

Electronic databases, including PubMed, Embase and Springer link, were searched through June 1, 2015, for eligible studies. Studies were included when they met the following criteria: 1) an observational study focusing on evaluating the risk factors for atherosclerosis in patients with KD; 2) KD was diagnosed clinically according to the Japan Kawasaki Disease Research Committee or American Heart Association's diagnostic criteria; 3) the study subjects were KD patients without coronary heart disease or related cardiovascular disease (KD group) and non-KD patients as control (control group), and 4) investigation of important atherosclerosis risk factors, total cholesterol (TC), low-density lipoprotein cholesterol (LDL), triglycerides (TG), systolic blood pressure (SBP), and flowmediated dilatation (FMD). The methodological quality of the included studies was evaluated using the Newcastle- Ottawa Scale. Mean difference (MD) and relative risk (RR) and corresponding 95% confidence intervals (CI) were used to calculate the pooled results.

RESULTS

Sixteen studies were included with a total of 870 patients, including 421 KD patients and 449 non-KD controls. Differences in TG and SBP between KD patients and controls were not significant; in contrast, TC and LDL levels were significantly higher in KD patients than the controls, whereas FMD in the KD patients was significantly lower.

CONCLUSIONS

KD patients may have an increased risk of developing atherosclerosis.

Discordance of Low-Density Lipoprotein and High-Density Lipoprotein Cholesterol Particle Versus Cholesterol Concentration for the Prediction of Cardiovascular Disease in Patients With Metabolic Syndrome and Diabetes Mellitus (from the Multi-Ethnic Study of Atherosclerosis [MESA])

A stronger association for low-density lipoprotein particle (LDL-P) and high-density lipoprotein particle (HDL-P) versus cholesterol concentrations (LDL-C and HDL-C) in predicting coronary heart disease (CHD) has been noted. We evaluate the role of these factors and extent of particle-cholesterol discordance in those with diabetes mellitus (DM) and metabolic syndrome (MetS) for event prediction. In the Multi-Ethnic Study of Atherosclerosis, we examined discordance of LDL and HDL (defined as a subject's difference between baseline particle and cholesterol percentiles), LDL-C, LDL-P, HDL-C, and HDL-P in relation to incident CHD and cardiovascular disease (CVD) events in subjects with DM, MetS (without DM), or neither condition using Cox regression. Of the 6,417 subjects with 10-year follow-up, those with MetS (n = 1,596) and DM (n = 838) had significantly greater LDL and HDL discordance compared with those without these conditions. In discordance models, only LDL discordance (per SD) within the MetS group was positively associated with CHD events (adjusted hazard ratio [HR] = 1.22, 95% confidence interval [CI] 1.01 to 1.48, p <0.05). In models with individual particle/cholesterol variables (per SD), within the DM group, HDL-P was inversely (HR 0.71, 95% CI 0.52 to 0.96, p <0.05) and LDL-C positively (HR 1.47, 95% CI 1.07 to 2.03, p <0.05) associated with CHD. In those with MetS, only LDL-P was positively associated with CHD (HR 1.34, 95% CI 1.00 to 1.78, p <0.05). Similar findings were also seen for CVD. LDL discordance and higher LDL-P in MetS, and higher LDL-C and lower HDL-P in DM, predict CHD and CVD, supporting a potential role for examining lipoprotein particles and discordances in those with MetS and DM.

Effect of ETC-1002 on Serum Low-Density Lipoprotein Cholesterol in Hypercholesterolemic Patients Receiving Statin Therapy

ETC-1002 is an oral, once-daily medication that inhibits adenosine triphosphate citrate lyase, an enzyme upstream of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, to reduce cholesterol biosynthesis. ETC-1002 monotherapy has demonstrated significant reduction in low-density lipoprotein cholesterol (LDL-C) compared with placebo in phase 2 studies. The objective of this study was to compare the lipid-lowering efficacy of ETC-1002 versus placebo when added to ongoing statin therapy in patients with hypercholesterolemia. This phase 2b, multicenter, double-blind trial (NCT02072161) randomized 134 hypercholesterolemic patients (LDL-C, 115 to 220 mg/dl) on stable background statin therapy to 12 weeks of add-on treatment with ETC-1002 120 mg, ETC-1002 180 mg, or placebo. The primary efficacy end point was the percent change in calculated LDL-C from baseline to week 12. For LDL-C, the least-squares mean percent change ± standard error from baseline to week 12 was significantly greater with ETC-1002 120 mg (-17 ± 4%, p = 0.0055) and ETC-1002 180 mg (-24 ± 4%, p <0.0001) than placebo (-4 ± 4%). ETC-1002 also dose dependently reduced apolipoprotein B by 15% to 17%, non-high-density lipoprotein cholesterol by 14% to 17%, total cholesterol by 13% to 15%, and LDL particle number by 17% to 21%. All these reductions in ETC-1002-treated cohorts were significantly greater than those with placebo. Rates of adverse events (AEs), muscle-related AEs, and discontinuations for AEs with ETC-1002 were similar to placebo. In conclusion, ETC-1002 120 mg or 180 mg added to stable statin therapy significantly reduced LDL-C compared to placebo and has a similar tolerability profile.

Triglyceride to high-density lipoprotein cholesterol ratio and carotid intima-medial thickness in Chinese adolescents with newly diagnosed type 2 diabetes mellitus

OBJECTIVE

To investigate the relationship between triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio and carotid intima-medial thickness (CIMT) in Chinese youth and adolescents with newly diagnosed type 2 diabetes mellitus (T2DM).

METHODS

Ninety-eight subjects aged 10-24 yr with newly-diagnosed T2DM had general inflammation, anthropometric, laboratory and CIMT data collected, and were divided into three groups based on TG/HDL-C tertiles.

RESULTS

There were no significant differences in gender, age, fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), and carotid arterial diameter (CAD) among the groups based on TG/HDL-C tertiles. Across TG/HDL-C tertiles, there was a significant progressive increase in body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), homeostasis model assessment-estimated insulin resistance (HOMA-IR), TG, total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and CIMT (all P < 0.01 or P < 0.05), while HDL-C was decreased significantly across the groups (P < 0.01). In general linear regression model, TG/HDL-C was an independent determinant of CIMT even after adjusting for BMI, SBP, DBP, TG, TC, LDL-C, HDL-C, HbA1c and HOMA-IR.

CONCLUSION

TG/HDL-C ratio, the marker of small dense LDL particles, is an independent determinant of CIMT in Chinese youth and adolescents with newly diagnosed T2DM, and may be a simple and helpful tool in predicting the increased CIMT in such patients.

Effect of Metformin Treatment on Lipoprotein Subfractions in Non-Diabetic Patients with Acute Myocardial Infarction: A Glycometabolic Intervention as Adjunct to Primary Coronary Intervention in ST Elevation Myocardial Infarction (GIPS-III) Trial

Objective

Metformin affects low density lipoprotein (LDL) and high density (HDL) subfractions in the context of impaired glucose tolerance, but its effects in the setting of acute myocardial infarction (MI) are unknown. We determined whether metformin administration affects lipoprotein subfractions 4 months after ST-segment elevation MI (STEMI). Second, we assessed associations of lipoprotein subfractions with left ventricular ejection fraction (LVEF) and infarct size 4 months after STEMI.

Methods

371 participants without known diabetes participating in the GIPS-III trial, a placebo controlled, double-blind randomized trial studying the effect of metformin (500 mg bid) during 4 months after primary percutaneous coronary intervention for STEMI were included of whom 317 completed follow-up (clinicaltrial.gov Identifier: NCT01217307). Lipoprotein subfractions were measured using nuclear magnetic resonance spectroscopy at presentation, 24 hours and 4 months after STEMI. (Apo)lipoprotein measures were obtained during acute STEMI and 4 months post-STEMI. LVEF and infarct size were measured by cardiac magnetic resonance imaging.

Results

Metformin treatment slightly decreased LDL cholesterol levels (adjusted P = 0.01), whereas apoB remained unchanged. Large LDL particles and LDL size were also decreased after metformin treatment (adjusted P<0.001). After adjustment for covariates, increased small HDL particles at 24 hours after STEMI predicted higher LVEF (P = 0.005). In addition, increased medium-sized VLDL particles at the same time point predicted a smaller infarct size (P<0.001).

Conclusion

LDL cholesterol and large LDL particles were decreased during 4 months treatment with metformin started early after MI. Higher small HDL and medium VLDL particle concentrations are associated with favorable LVEF and infarct size.

Effect of PCSK9 Inhibition by Alirocumab on Lipoprotein Particle Concentrations Determined by Nuclear Magnetic Resonance Spectroscopy

BACKGROUND

In patients with discordance between low-density lipoprotein (LDL) cholesterol and LDL particle (LDL-P) concentrations, cardiovascular risk more closely correlates with LDL-P.

METHODS AND RESULTS

We investigated the effect of alirocumab, a fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9, on lipoprotein particle concentration and size in hypercholesterolemic patients, using nuclear magnetic resonance spectroscopy. Plasma samples were collected from patients receiving alirocumab 150 mg every 2 weeks (n=26) or placebo (n=31) during a phase II, double-blind, placebo-controlled trial in patients (LDL cholesterol ≥100 mg/dL) on a stable atorvastatin dose. In this post hoc analysis, percentage change in concentrations of LDL-P, very-low-density lipoprotein particles, and high-density lipoprotein particles from baseline to week 12 was determined by nuclear magnetic resonance. Alirocumab significantly reduced mean concentrations of total LDL-P (-63.3% versus -1.0% with placebo) and large (-71.3% versus -21.8%) and small (-54.0% versus +17.8%) LDL-P subfractions and total very-low-density lipoprotein particle concentrations (-36.4% versus +33.4%; all P<0.01). Total high-density lipoprotein particles increased with alirocumab (+11.2% versus +1.4% with placebo; P<0.01). There were greater increases in large (44.6%) versus medium (17.7%) or small high-density lipoprotein particles (2.8%) with alirocumab. LDL-P size remained relatively unchanged in both groups; however, very-low-density and high-density lipoprotein particle sizes increased to a significantly greater extent with alirocumab.

CONCLUSIONS

Alirocumab significantly reduced LDL-C and LDL-P concentrations in hypercholesterolemic patients receiving stable atorvastatin therapy. These findings may be of particular relevance to patients with discordant LDL-C and LDL-P concentrations.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifier: NCT01288443.

A comparative study of four independent methods to measure LDL particle concentration

BACKGROUND

Low-density lipoprotein particle concentration (LDL-P) is generally more predictive of clinical cardiovascular endpoints than LDL cholesterol (LDL-C). Few studies have directly compared multiple LDL-P methods, particularly with ultracentrifugation.

OBJECTIVE

Examine comparability and precision of 4 LDL-P methods.

METHODS

We divided serum from 48 subjects into blinded triplicates and measured LDL-P in 3 separate laboratories by 4 methods: ultracentrifugation (reference method), a novel electrophoretic method, and nuclear magnetic resonance spectroscopy (NMR) by 2 independent methods: a 400 MHz Vantera(®) instrument supplied by Liposcience (LS-NMR) and operated at ARUP Laboratories, and a 600 MHz Bruker instrument (ASCEND 600) operated at Health Diagnostic Laboratory (HD-NMR).

RESULTS

Of the 4 methods, ultracentrifugation was the most precise and LS-NMR the least; the latter had a significantly greater CV (p < 0.0001) as compared with all 3 of the other methods, although all CVs were clinically acceptable. The electrophoretic method showed similar precision to ultracentrifugation, while HD-NMR was intermediate. The HD-NMR had the slope closest to 1 (0.90, 95% CI 0.71 to 1.09) and the intercept closest to 0 (-48, -353 to 256) compared to the ultracentrifugation method in Deming regression models. While the two NMR methods correlated well (r = 0.95) with each other and had a slope equivalent to 1 (1.08, 0.98 to 1.19), their intercept in Deming regression excluded 0 (194, 53 to 335) indicating a vertical shift between the two methods.

CONCLUSIONS

This LDL-P method comparison may prove useful for future research and clinical applications.

The emergence of proton nuclear magnetic resonance metabolomics in the cardiovascular arena as viewed from a clinical perspective

The ability to phenotype metabolic profiles in serum has increased substantially in recent years with the advent of metabolomics. Metabolomics is the study of the metabolome, defined as those molecules with an atomic mass less than 1.5 kDa. There are two main metabolomics methods: mass spectrometry (MS) and proton nuclear magnetic resonance (¹H NMR) spectroscopy, each with its respective benefits and limitations. MS has greater sensitivity and so can detect many more metabolites. However, its cost (especially when heavy labelled internal standards are required for absolute quantitation) and quality control is sub-optimal for large cohorts. ¹H NMR is less sensitive but sample preparation is generally faster and analysis times shorter, resulting in markedly lower analysis costs. ¹H NMR is robust, reproducible and can provide absolute quantitation of many metabolites. Of particular relevance to cardio-metabolic disease is the ability of ¹H NMR to provide detailed quantitative data on amino acids, fatty acids and other metabolites as well as lipoprotein subparticle concentrations and size. Early epidemiological studies suggest promise, however, this is an emerging field and more data is required before we can determine the clinical utility of these measures to improve disease prediction and treatment.

This review describes the theoretical basis of ¹H NMR; compares MS and ¹H NMR and provides a tabular overview of recent ¹H NMR-based research findings in the atherosclerosis field, describing the design and scope of studies conducted to date. ¹H NMR metabolomics-CVD related research is emerging, however further large, robustly conducted prospective, genetic and intervention studies are needed to advance research on CVD risk prediction and to identify causal pathways amenable to intervention.

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¹H NMR metabolomics is being increasingly applied to large cohort studies.

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Studies have identified potentially novel lipoprotein and metabolite predictors for CVD.

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Potential exists for the use of metabolomics in cardiovascular clinical practice.

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Current findings are too preliminary to translate into clinical recommendations.

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Further large scale studies are now needed to advance the field in a robust manner.