Genetic causes of high and low serum HDL-cholesterol

Investigating the sources of variable impact of pathogenic variants in monogenic metabolic conditions

Over three percent of people carry a dominant pathogenic variant, yet only a fraction of carriers develop disease. Disease phenotypes from carriers of variants in the same gene range from mild to severe. Here, we investigate underlying mechanisms for this heterogeneity: variable variant effect sizes, carrier polygenic backgrounds, and modulation of carrier effect by genetic background (marginal epistasis). We leveraged exomes and clinical phenotypes from the UK Biobank and the Mt. Sinai BioMe Biobank to identify carriers of pathogenic variants affecting cardiometabolic traits. We employed recently developed methods to study these cohorts, observing strong statistical support and clinical translational potential for all three mechanisms of variable carrier penetrance and disease severity. For example, scores from our recent model of variant pathogenicity were tightly correlated with phenotype amongst clinical variant carriers, they predicted effects of variants of unknown significance, and they distinguished gain- from loss-of-function variants. We also found that polygenic scores modify phenotypes amongst pathogenic carriers and that genetic background additionally alters the effects of pathogenic variants through interactions.

The impact of vitamin D supplementation on glycemic control and lipid metabolism in polycystic ovary syndrome: a systematic review of randomized controlled trials

BACKGROUND

Polycystic ovary syndrome (PCOS) is a prevalent endocrine condition affecting both metabolic and reproductive health in women. The impact of vitamin D on metabolic regulation has attracted growing interest. The purpose of this study is to investigate the impact of vitamin D supplementation on key metabolic parameters-namely blood glucose, insulin, and lipid levels-in individuals with PCOS.

METHODS

A systematic review was conducted to identify relevant studies in PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov. The search focused on randomized controlled trials (RCTs) evaluating the impact of vitamin D supplementation in patients with PCOS. Meta-analysis was performed using RevMan 5.3 software, and study quality was evaluated with the Cochrane Risk of Bias Tool. In addition, outcome-related evidence was graded using the GRADE system, and TSA was performed to determine if the number of participants met the required threshold.

RESULTS

A total of 691 individuals with PCOS from 13 RCTs were evaluated. The meta-analysis indicated that the supplementation of vitamin D led to a notable reduction in the subsequent metabolic parameters: fasting blood glucose[MD=-2.91 mg/dL, 95% CI (-4.78, -1.04) mg/dL, P = 0.002], insulin levels[MD=-1.98 µIU/mL, 95% CI (-3.32, -0.64) µIU/mL, P = 0.004], triglycerides[MD=-11.01 mg/dL, 95% CI (-16.42, -5.61) mg/dL, P < 0.0001], total cholesterol [MD=-11.69 mg/dL, 95% CI (-15.56, -7.82) mg/dL, P < 0.00001], very low-density lipoprotein cholesterol (VLDL-cholesterol) [MD=-2.64 mg/dL, 95% CI (-4.50, -0.79) mg/dL, P = 0.005], and low-density lipoprotein cholesterol (LDL-cholesterol) [MD=-5.85 mg/dL, 95% CI (-10.28, -1.42) mg/dL, P = 0.010]. Nevertheless, the supplementation of vitamin D did not exert a significant impact on high - density lipoprotein cholesterol (HDL - cholesterol) [MD=-0.21 mg/dL, 95% CI (-0.81, 1.22) mg/dL, P = 0.69]. Begg's and Egger's tests suggested a minimal probability of publication bias, and the TSA confirmed that the optimal sample size for major outcomes had been reached, supporting the robustness of the meta-analysis results.

CONCLUSION

Vitamin D supplementation shows significant benefits in improving metabolic parameters in PCOS patients, particularly in reducing fasting blood glucose, insulin, and lipid levels, suggesting a potential role of vitamin D in PCOS management. The long-term outcomes and most effective dose of vitamin D warrant further investigation in future research.

CLINICAL TRIAL NUMBER

Not applicable.

Association of atherogenic indices and triglyceride-total cholesterol-body weight index (TCBI) with severity of stenosis in patients undergoing angiography: a case-control study

OBJECTIVES

Coronary artery disease, caused by atherosclerosis, necessitates assessing plaque formation risk using indices like the atherogenic index of plasma (AIP), Castelli's risk indexes (CRI-I and CRI-II), the atherogenic coefficient (AC), and the triglyceride-total cholesterol-body weight index (TCBI). Although TCBI primarily assesses mortality risk, its relationship with stenosis severity is unclear. Utilizing data from a prior study, a case-control analysis was conducted on 1,187 subjects, which included 781 patients who underwent coronary angiography and 406 healthy controls. The indices were compared across varying degrees of arterial blockages.

RESULTS

AIP significantly correlated with stenosis severity in women, increasing the risk of three-vessel stenosis by 2.5 times. AC raised the risk of single-vessel stenosis in men by 2.7 times. CRI-I and CRI-II showed a positive relationship with arterial stenosis in women, with CRI-I increasing the risk of two and three-vessel blockages by 21.9% and 22.4%, respectively. A one-unit increase in CRI-II raised the risk by 33.1% for two arteries and 25.3% for three. In conclusion, AIP, CRI-I, and CRI-II in women, along with AC in men, correlated with arterial stenosis severity, while TCBI did not. Further research is needed to determine which index is most effective in predicting CAD risk.

Gene-Diet Interactions in High-Density Lipoprotein Cholesterol-Related Polymorphisms and Cardiovascular Disease Risk: Insights from the Korean Genome and Epidemiology Study

Background: Understanding gene-diet interactions is crucial for establishing dietary guidelines for cardiovascular diseases (CVD). This study analyzed the interaction between dietary intake and six genome-wide association study (GWAS)-identified single nucleotide polymorphisms (SNP) associated with high-density lipoprotein (HDL) cholesterol levels and their impact on CVD risk. Methods: A total of 68,806 participants in the Korean Genome and Epidemiology Study (KoGES) were analyzed. Six target SNPs (LPL: rs17482753; ABCA1: rs1883025; APOA5: rs651821; LIPC: rs1077835; CETP: rs17231506; and LIPG: rs9953437) were extracted from genome-wide SNP genotype data. Dietary intake was assessed using a food frequency questionnaire. SNP genotyping was conducted using the Korea Biobank Array (Korean Chip), a specialized genotyping platform designed for GWAS of blood biochemical traits in the Korean population. SNP-diet interactions on CVD risk were analyzed using generalized linear models (GLM). Results: Among the six SNPs, ABCA1: rs1883025 and APOA5: rs651821 showed significant gene-diet interactions. For rs1883025 (ABCA1), carriers of the T allele exhibited reduced HDL cholesterol levels. However, in the high-protein intake group, individuals with the T/T genotype had a significantly lower risk of ischemic stroke compared to those in the low-protein intake group (interaction p-value = 0.044). For rs651821 (APOA5), carriers of the T allele also had lower HDL cholesterol levels, but individuals with the C/C genotype (wild-type homozygotes) in the low-fat intake group showed a significantly reduced risk of coronary artery disease (interaction p-value = 0.0155). Conclusions: This study suggests potential interactions between polymorphisms associated with low HDL cholesterol and dietary patterns, particularly high-protein and low-fat diets, in relation to CVD risk. These findings highlight the importance of personalized dietary recommendations based on genetic profiles to reduce CVD risk. They provide a basis for future research aimed at developing precision nutrition guidelines and targeted interventions to manage hypo-HDL cholesterolemia and nutrition-related CVD risks.

DNA methylation profiling at base-pair resolution reveals unique epigenetic features of early-onset colorectal cancer in underrepresented populations

BACKGROUND

The incidence of early-onset colorectal cancer (EOCRC) has been rising at an alarming rate in the USA, and EOCRC disproportionately affects racial/ethnic minorities. Here, we construct comprehensive profiles of EOCRC DNA methylomes at base-pair resolution for a cohort of Hispanic and African American patients.

RESULTS

We show the epigenetic landscape of these EOCRC patients differs from that of late-onset colorectal cancer patients, and methylation canyons in EOCRC tumor tissue preferentially overlapped genes in cancer-related pathways. Furthermore, we identify epigenetic alterations in metabolic genes that are specific to our racial/ethnic minority EOCRC cohort but not Caucasian patients from TCGA. Top genes differentially methylated between these cohorts included the obesity-protective MFAP2 gene as well as cancer risk susceptibility genes APOL3 and RNASEL.

CONCLUSIONS

In this study, we provide to the scientific community high-resolution DNA methylomes for a cohort of EOCRC patients from underrepresented populations. Our exploratory findings in this cohort highlight epigenetic mechanisms underlying the pathogenesis of EOCRC and nominate novel biomarkers for EOCRC in underrepresented populations.

Investigation of the relationship between atherogenic index, anthropometric characteristics, and 10-year risk of metabolic syndrome: a population-based study

BACKGROUND

People with metabolic syndrome (MetS) are at a higher risk of coronary artery disease, diabetes mellitus, stroke, osteoarthritis, and some types of cancers. Finding markers which are available and inexpensive are most useful for the prediction of MetS. The present study aimed to determine the relationship between atherogenic index and anthropometric indicators and the 10-year risk of MetS.

METHODS

During the 10-year follow-up on Mashhad stroke and heart atherosclerotic disorder (MASHAD study), 4684 subjects who did not MetS at baseline were recruited in this study. The anthropometric indices and atherogenic index including atherogenic index of plasma (AIP), Castelli's risk index I and II (CRI-I, CRI-I), and atherogenic coefficient (AC) were measured. SPSS-23 was used for all statistical analyses.

RESULT

Among subjects who did not have MetS at baseline 1599 cases (34.1%) developed MetS. The anthropometric and lipid indices were significantly elevated in patients with MetS compared to the healthy ones (p < 0.001). It was revealed that an increase of one unit in AIP and AC can raise the risk of MetS 22.7% (OR: 1.227 (95% CI, 1.166-1.291)) and 37.7% (OR: 1.377 (95% CI, 1.291-1.468)), respectively. Moreover, increasing one unit of WHtR decreases the risk of MetS by 8.5% (OR: 0.915 (95% CI, 0.886-0.946)).

CONCLUSION

The results of this longitudinal study showed that increasing AC and AIP could enhance the risk of MetS. The present study also indicated that AC and AIP are useful predictors in the clinical setting for identifying individuals with MetS in the Iranian adult population.

Glucose and Lipid Metabolism Disorders in Adults with Spinal Muscular Atrophy Type 3

BACKGROUND

Spinal muscular atrophy type 3 (juvenile SMA, Kugelberg-Welander disease) is a genetic disease caused by changes in the survival motor neuron 1 (SMN) gene. However, there is increasing evidence of metabolic abnormalities in SMA patients, such as altered fatty acid metabolism, impaired glucose tolerance, and defects in the functioning of muscle mitochondria. Given that data in the literature are scarce regarding this subject, the purpose of this study was to estimate the prevalence of glucose and lipid metabolism disorders in adult patients with SMA type 3.

METHODS

We conducted a cross-sectional study of 23 adult patients with SMA type 3 who underwent a comprehensive evaluation, including a physical examination, biochemical analysis, and an oral glucose tolerance test during 2020-2023.

RESULTS

At least one lipid abnormality was observed in 60.8% of patients. All four lipid parameters were atypical in 4.3% of patients, three lipid parameters were abnormal in 21.7% of patients, and two lipid parameters were altered in 8.7% patients. A total of 91.3% of SMA3 patients met the HOMA-IR criteria for insulin resistance, with 30.43% having impaired glucose tolerance. None of the patients met the criteria for a diagnosis of overt DM2.

CONCLUSIONS

The prevalence of dyslipidemia and altered glucose metabolism in our study sets apart the adult population with SMA3 from the general population, confirming a significant interplay between muscle, liver, and adipose tissue. Ensuring metabolic care for aging patients with SMA 3 is crucial, as they are vulnerable to metabolic derangements and cardiovascular risks.

The effects of shift work on sleep quality, diet quality, and obesity-related factors: A male population study

Recent studies suggest that shift working may trigger health issues through disrupted circadian rhythms and altered eating habits. This study aimed to examine the possible associations of shift work with sleep quality, diet quality and obesity-related parameters. This study was conducted with 150 males (75 shift and daytime workers) aged 24-50 years. Dietary intake was determined using the 24-hour recall method, and dietary quality was evaluated using the Healthy Eating Index-2010 (HEI-2010). Anthropometrical measurements and body composition were assessed. The Pittsburgh Sleep Quality Index was used to evaluate sleep quality. Fasting and postprandial glucose and insulin, and fasting lipid levels were analyzed. HOMA-IR was calculated, and blood pressure was measured. The total HEI-2010 score of shift workers (52.6 [45.4-58.8]) was lower than the daytime workers (55.9 [49.1-64.9]) (p = 0.016). Among individuals with good sleep quality, the total HEI-2010 score, seafood and plant proteins, fatty acids, and sodium scores were lower in shift workers compared to others (p < 0.05 for each). Non-obese shift workers had higher body weight, waist circumference, waist/hip ratio, VLDL-cholesterol, triglyceride, postprandial glucose, and insulin levels compared to daytime workers (p < 0.05 for each). This study demonstrates that shift working is associated with lower diet quality independent of sleep quality.

Association between high-density lipoprotein and functional outcome of ischemic stroke patients in a Taiwanese population

Despite recent findings indicating a paradoxical association between high-density lipoprotein cholesterol (HDL-C) levels and cardiovascular disease (CVD) mortality, the impact of HDL-C on subsequent outcomes after ischemic stroke remains unclear. The study aims to investigate the relationships between HDL-C levels and post-stroke functional outcomes while examining the potential modifying influence of HDL-C-related single nucleotide polymorphisms identified through genome-wide association studies. This cohort study included 1,310 patients diagnosed with acute ischemic stroke (AIS), all of whom had their admission serum lipid profile and genotyping information. Participants were categorized into four groups based on gender and HDL-C level. Prognostic outcomes were assessed using a modified Rankin Scale (mRS) at 1, 3, and 12 months post-admission. Multivariate logistic regression and restricted cubic spline regression analysis were used to assess the associations between HDL-C levels and outcomes. The mean age of patients was 61.17 ± 12.08 years, and 69.31% were men. After adjusting confounders, patients with the highest HDL-C level group had a significantly higher risk of poor functional outcomes at 1, 3, and 12 months following stroke compared to the reference group. Restricted cubic splines depicted a nonlinear association between HDL-C levels and poor prognosis in both men and women. The ABCA1 gene rs2575876 AA genotype combined with abnormal HDL-C levels exhibited a significantly heightened risk of post-stroke adverse outcomes at 1 and 3 months compared to patients with normal HDL-C levels and GG + GA genotype. These findings suggest that the combined effects of ABCA1 genetic variants with either low or high HDL-C levels could further heighten this risk.

Inferring causal direction between two traits using R2 with application to transcriptome-wide association studies

In Mendelian randomization, two single SNP-trait correlation-based methods have been developed to infer the causal direction between an exposure (e.g., a gene) and an outcome (e.g., a trait), called MR Steiger's method and its recent extension called Causal Direction-Ratio (CD-Ratio). Here we propose an approach based on R2, the coefficient of determination, to combine information from multiple (possibly correlated) SNPs to simultaneously infer the presence and direction of a causal relationship between an exposure and an outcome. Our proposed method generalizes Steiger's method from using a single SNP to multiple SNPs as IVs. It is especially useful in transcriptome-wide association studies (TWASs) (and similar applications) with typically small sample sizes for gene expression (or another molecular trait) data, providing a more flexible and powerful approach to inferring causal directions. It can be applied to GWAS summary data with a reference panel. We also discuss the influence of invalid IVs and introduce a new approach called R2S to select and remove invalid IVs (if any) to enhance the robustness. We compared the performance of the proposed method with existing methods in simulations to demonstrate its advantages. We applied the methods to identify causal genes for high/low-density lipoprotein cholesterol (HDL/LDL) using the individual-level GTEx gene expression data and UK Biobank GWAS data. The proposed method was able to confirm some well-known causal genes while identifying some novel ones. Additionally, we illustrated an application of the proposed method to GWAS summary to infer causal relationships between HDL/LDL and stroke/coronary artery disease (CAD).

Investigating the sources of variable impact of pathogenic variants in monogenic metabolic conditions

Over three percent of people carry a dominant pathogenic variant, yet only a fraction of carriers develop disease. Disease phenotypes from carriers of variants in the same gene range from mild to severe. Here, we investigate underlying mechanisms for this heterogeneity: variable variant effect sizes, carrier polygenic backgrounds, and modulation of carrier effect by genetic background (marginal epistasis). We leveraged exomes and clinical phenotypes from the UK Biobank and the Mt. Sinai BioMe Biobank to identify carriers of pathogenic variants affecting cardiometabolic traits. We employed recently developed methods to study these cohorts, observing strong statistical support and clinical translational potential for all three mechanisms of variable carrier penetrance and disease severity. For example, scores from our recent model of variant pathogenicity were tightly correlated with phenotype amongst clinical variant carriers, they predicted effects of variants of unknown significance, and they distinguished gain- from loss-of-function variants. We also found that polygenic scores predicted phenotypes amongst pathogenic carriers and that epistatic effects can exceed main carrier effects by an order of magnitude.

Tracking of serum lipid levels from childhood to adulthood: Systematic review and meta-analysis

BACKGROUND AND AIMS

The utility of lipid screening in pediatric settings for preventing adult atherosclerotic cardiovascular diseases partly depends on the lifelong tracking of lipid levels. This systematic review aimed to quantify the tracking of lipid levels from childhood and adolescence to adulthood.

METHODS

We systematically searched MEDLINE, Embase, Web of Science, and Google Scholar in March 2022. The protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO; ID: CRD42020208859). We included cohort studies that measured tracking of lipids from childhood or adolescence (<18 years) to adulthood (≥18) with correlation or tracking coefficients. We estimated pooled correlation and tracking coefficients using random-effects meta-analysis. Risk of bias was assessed with a review-specific tool.

RESULTS

Thirty-three studies of 19 cohorts (11,020 participants) were included. The degree of tracking from childhood and adolescence to adulthood differed among lipids. Tracking was observed for low-density lipoprotein cholesterol (pooled r = 0.55-0.65), total cholesterol (pooled r = 0.51-0.65), high-density lipoprotein cholesterol (pooled r = 0.46-0.57), and triglycerides (pooled r = 0.32-0.40). Only one study included tracking of non-high-density lipoprotein cholesterol (r = 0.42-0.59). Substantial heterogeneity was observed. Study risk of bias was moderate, mostly due to insufficient reporting and singular measurements at baseline and follow-up.

CONCLUSIONS

Early-life lipid measurements are important for predicting adult levels. However, further research is needed to understand the tracking of non-high-density lipoprotein cholesterol and the stability of risk classification over time, which may further inform pediatric lipid screening and assessment strategies.

Cardiovascular Disease Prevalence in Asians Versus Americans: A Review of Genetics, Diet, and the Call for Enhanced Prevention and Screening

Cardiovascular disease (CVD) continues to pose a global health challenge, demonstrating significant disparities in occurrence among various populations. A wide number of research studies have indicated a higher prevalence of cardiovascular disease in South Asian immigrants compared to the local American population. The demand to improve the cardiovascular benefits of immigrants is increasing, which calls for further research with larger and more diverse population samples. This study will investigate the major causes of this variation, which include genetically diverse characteristics and changes in nutritional status among the study population groups. To assess the increase in the prevalence of cardiovascular disease among South Asian populations compared to the US population, a narrative review of accessible data is carried out. The data in support of the present document are from the Centre for Disease Prevention and Control, Statistics for Heart Diseases and Stroke 2023, a trend analysis about incidences of cardiac diseases and global burden in 2017, all dating back to the last two decades. Relevant articles from PubMed and Google Scholar have also been included, as appropriate, and their references are provided wherever necessary. Graphs for the geographical variations in disease incidence are produced using Microsoft Excel (Microsoft® Corp., Redmond, WA). The review shows that there is a significant decline in the prevalence of CVD among American citizens when compared to the steady increase in the number of cases among South Asians, which is attributed to the unique genetic predisposition of South Asians to be more prone to CVDs. The changing dietary habits also play an important role in the fall in HDL levels in South Asians when compared to Americans. This is driven by genetic disparities, including the APOA1 and APOA2 genes, and nutritional disparities, including variance in quality and quantity of dietary consumption. Addressing the escalating cases of CVD among South Asians necessitates additional research to enhance proactive preventive measures and implement screening programs specifically tailored to address prevalent risk factors within the population.

Association between high-density lipoprotein cholesterol and lumbar bone mineral density in Chinese: a large cross-sectional study

BACKGROUND

The association between lipid and bone metabolism, particularly the role of high-density lipoprotein cholesterol (HDL-C) in regulating bone mineral density (BMD), is of significant interest. Despite numerous studies, findings on this relationship remain inconclusive, especially since evidence from large, sexually diverse Chinese populations is sparse. This study, therefore, investigates the correlation between HDL-C and lumbar BMD in people of different genders using extensive population-based data from physical examinations conducted in China.

METHODS

Data from a cross-sectional survey involving 20,351 individuals aged > = 20 years drawn from medical records of health check-ups at the Health Management Centre of the Henan Provincial People's Hospital formed the basis of this study. The primary objective was to determine the correlation between HDL-C levels and lumbar BMD across genders. The analysis methodology included demographic data analysis, one-way ANOVA, subgroup analyses, multifactorial regression equations, smoothed curve fitting, and threshold and saturation effect analyses.

RESULTS

Multifactorial regression analysis revealed a significant inverse relationship between HDL-C levels and lumbar BMD in both sexes, controlling for potential confounders (Male: β = -8.77, 95% CI -11.65 to -5.88, P < 0.001; Female: β = -4.77, 95% CI -8.63 to -0.90, P = 0.015). Subgroup and threshold saturation effect analyses indicated a stronger association in males, showing that increased HDL-C correlates with reduced lumbar BMD irrespective of age and body mass index (BMI). The most significant effect was observed in males with BMI > 28 kg/m2 and HDL-C > 1.45 mmol/L and in females with a BMI between 24 and 28 kg/m2.

CONCLUSION

Elevated HDL-C is associated with decreased bone mass, particularly in obese males. These findings indicate that individuals with high HDL-C levels should receive careful clinical monitoring to mitigate osteoporosis risk.

TRIAL REGISTRATION

The research protocol received ethics approval from the Ethics Committee at Beijing Jishuitan Hospital, in conformity with the Declaration of Helsinki guidelines (No. 2015-12-02). These data are a contribution of the China Health Quantitative CT Big Data Research team, registered at clinicaltrials.gov (code: NCT03699228).

A decreased level of high-density lipoprotein is a possible risk factor for type 2 diabetes mellitus: A review

Introduction

Type 2 diabetes mellitus (T2DM) is characterized primarily by dyslipidemia and hyperglycemia due to insulin resistance. High-density lipoprotein (HDL) play a significant role in preventing the incidence of dyslipidemia and its complications. HDL has different protective functions, such as reducing oxidation, vascular inflammation, and thrombosis; additionally, its anti-diabetic role is one of the most significant recent discoveries about HDL and some of its constituent lipoproteins.

Methods

This research reviews ongoing studies and preliminary investigations into the assessment of relation between decreased level of HDL and T2DM.

Results

The levels of HDL and its functions contribute to glucose hemostasis and the development of T2DM through four possible mechanisms, including insulin secretion by beta cells, peripheral insulin sensitivity, non-insulin-dependent glucose uptake, and adipose tissue metabolic activity. Additionally, the anti-oxidant properties of HDL protect beta cells from apoptosis caused by oxidative stress and inflammation induced by low-density lipoprotein, which facilitate insulin secretion.

Conclusion

Therefore, HDL and its compositions, especially Apo A-I, play an important role in regulating glucose metabolism, and decreased levels of HDL can be considered a risk factor for DM. Different factors, such as hypoalphalipoproteinemia that manifests as a consequence of genetic factors, such as Apo A-I deficiency, as well as secondary causes arising from lifestyle choices and underlying medical conditions that decrease the level of HDL, could be associated with DM. Moreover, intricate connections between HDL and diabetic complications extend beyond glucose metabolism to encompass complications like cardiovascular disease and kidney disease. Therefore, the exact interactions between HDL level and DM should be evaluated in future studies.

High-Density Lipoprotein Cholesterol in Atherosclerotic Cardiovascular Disease Risk Assessment: Exploring and Explaining the "U"-Shaped Curve

PURPOSE OF REVIEW

Review updates for the association of HDL-cholesterol with atherosclerotic cardiovascular disease (ASCVD) and discuss the approach to incorporating HDL-cholesterol within risk assessment.

RECENT FINDINGS

There is a U-shaped relationship between HDL-cholesterol and ASCVD. Both low HDL-cholesterol (< 40 mg/dL in men, < 50 mg/dL in women) and very-high HDL-cholesterol (≥ 80 mg/dL in men) are associated with a higher risk of all-cause and ASCVD mortality, independent from traditional risk factors. There has been inconsistency for the association between very-high HDL-cholesterol and mortality outcomes in women. It is uncertain whether HDL-cholesterol is a causal ASCVD risk factor, especially due to mixed results from Mendelian randomization studies and the collinearity of HDL-cholesterol with established risk factors, lifestyle behaviors, and socioeconomic status. HDL-cholesterol is a risk factor or risk enhancer in primary prevention and high-risk condition in secondary prevention when either low (men and women) or very-high (men). The contribution of HDL-cholesterol to ASCVD risk calculators should reflect its observed U-shaped association with all-cause and ASCVD mortality.

The Influence of Lifestyle on High-Density Lipoprotein Concentration among Mexican Emerging Adults

Previous studies have highlighted the role of lifestyle on HDL-C concentrations in adults. To our knowledge, the health and nutritional status of emerging adults have been understudied. The present study aimed to explore the most important lifestyle factors, including micronutrient intake adequacy and the percentage of energy from food processing, according to HDL-C concentrations in emerging adults. In this context, a cross-sectional analysis was conducted on 261 Mexican emerging adults who were apparently healthy. Lifestyle factors were collected through a structured survey and the prevalence of micronutrient intake inadequacy was estimated using the estimated average requirement cut-point method. The percentage of energy from ultra-processed foods was assessed using the NOVA system. HDL-C was determined using the enzymatic colorimetric method. Statistical analyses were conducted in SPSS. The results revealed that lifestyle factors do not differ according to HDL-C status. The participants showed a poor nutritional diet that was energy-dense and micronutrient-inadequate. Nearly half of their energy came from processed and ultra-processed foods. Most participants did not meet the recommendations for key nutrients (ϖ3 fatty acids and phytosterols) that promote a healthy lipid status. In conclusion, regardless of their HDL-C levels, emerging adults exhibited lifestyle-related risk factors. The persistence of these findings over time could contribute to the development of metabolic disorders in the future. It is crucial to increase understanding and to develop effective nutritional interventions during this critical phase of life.

Determination of genetic correlation between tobacco smoking and coronary artery disease

Backgrounds

Tobacco smoking is an important risk factor for coronary artery disease (CAD), but the genetic mechanisms linking smoking to CAD remain largely unknown.

Methods

We analyzed summary data from the genome-wide association study (GWAS) of the UK Biobank for CAD, plasma lipid concentrations (n = 184,305), and smoking (n = 337,030) using different biostatistical methods, which included LD score regression and Mendelian randomization (MR).

Results

We identified SNPs shared by CAD and at least one smoking behavior, the genes where these SNPs are located were found to be significantly enriched in the processes related to lipoprotein metabolic, chylomicron-mediated lipid transport, lipid digestion, mobilization, and transport. The MR analysis revealed a positive correlation between smoking cessation and decreased risk for CAD when smoking cessation was considered as exposure (p = 0.001), and a negative correlation between the increased risk for CAD and smoking cessation when CAD was considered as exposure (p = 2.95E-08). This analysis further indicated that genetic liability for smoking cessation increased the risk of CAD.

Conclusion

These findings inform the concomitant conditions of CAD and smoking and support the idea that genetic liabilities for smoking behaviors are strongly associated with the risk of CAD.

Deciphering structural aspects of reverse cholesterol transport: mapping the knowns and unknowns

Atherosclerosis is a major contributor to the onset and progression of cardiovascular disease (CVD). Cholesterol-loaded foam cells play a pivotal role in forming atherosclerotic plaques. Induction of cholesterol efflux from these cells may be a promising approach in treating CVD. The reverse cholesterol transport (RCT) pathway delivers cholesteryl ester (CE) packaged in high-density lipoproteins (HDL) from non-hepatic cells to the liver, thereby minimising cholesterol load of peripheral cells. RCT takes place via a well-organised interplay amongst apolipoprotein A1 (ApoA1), lecithin cholesterol acyltransferase (LCAT), ATP binding cassette transporter A1 (ABCA1), scavenger receptor-B1 (SR-B1), and the amount of free cholesterol. Unfortunately, modulation of RCT for treating atherosclerosis has failed in clinical trials owing to our lack of understanding of the relationship between HDL function and RCT. The fate of non-hepatic CEs in HDL is dependent on their access to proteins involved in remodelling and can be regulated at the structural level. An inadequate understanding of this inhibits the design of rational strategies for therapeutic interventions. Herein we extensively review the structure-function relationships that are essential for RCT. We also focus on genetic mutations that disturb the structural stability of proteins involved in RCT, rendering them partially or completely non-functional. Further studies are necessary for understanding the structural aspects of RCT pathway completely, and this review highlights alternative theories and unanswered questions.

HDL Function and Size in Patients with On-Target LDL Plasma Levels and a First-Onset ACS

Patients admitted for acute coronary syndrome (ACS) usually have high cardiovascular risk scores with low levels of high-density lipoprotein cholesterol (HDL-C) and high low-density lipoprotein cholesterol (LDL-C) levels. Here, we investigated the role of lipoprotein functionality as well as particle number and size in patients with a first-onset ACS with on-target LDL-C levels. Ninety-seven patients with chest pain and first-onset ACS with LDL-C levels of 100 ± 4 mg/dL and non-HDL-C levels of 128 ± 4.0 mg/dL were included in the study. Patients were categorized as ACS and non-ACS after all diagnostic tests were performed (electrocardiogram, echocardiogram, troponin levels and angiography) on admission. HDL-C and LDL-C functionality and particle number/size by nuclear magnetic resonance (NMR) were blindly investigated. A group of matched healthy volunteers (n = 31) was included as a reference for these novel laboratory variables. LDL susceptibility to oxidation was higher and HDL-antioxidant capacity lower in the ACS patients than in the non-ACS individuals. ACS patients had lower HDL-C and Apolipoprotein A-I levels than non-ACS patients despite the same prevalence of classical cardiovascular risk factors. Cholesterol efflux potential was impaired only in the ACS patients. ACS-STEMI (Acute Coronary Syndrome—ST-segment-elevation myocardial infarction) patients, had a larger HDL particle diameter than non-ACS individuals (8.4 ± 0.02 vs. 8.3 ± 0.02 and, ANOVA test, p = 0.004). In conclusion, patients admitted for chest pain with a first-onset ACS and on-target lipid levels had impaired lipoprotein functionality and NMR measured larger HDL particles. This study shows the relevance of HDL functionality rather than HDL-C concentration in ACS patients.

Interaction between SIDT2 and ABCA1 Variants with Nutrients on HDL-c Levels in Mexican Adults

Previous studies have reported that the SIDT2 and ABCA1 genes are involved in lipid metabolism. We aimed to analyze the association-the gene x gene interaction between rs17120425 and rs1784042 on SIDT2 and rs9282541 on ABCA1 and their diet interaction on the HDL-c serum levels-in a cohort of 1982 Mexican adults from the Health Workers Cohort Study. Demographic and clinical data were collected through a structured questionnaire and standardized procedures. Genotyping was performed using a predesigned TaqMan assay. The associations and interactions of interest were estimated using linear and logistic regression. Carriers of the rs17120425-A and rs1784042-A alleles had slightly higher blood HDL-c levels compared to the non-carriers. In contrast, rs9282541-A was associated with low blood HDL-c levels (OR = 1.34, p = 0.013). The rs1784042 x rs9282541 interaction was associated with high blood HDL-c levels (p = 3.4 × 10-4). Premenopausal women who carried at least one rs17120425-A allele and consumed high dietary fat, protein, monounsaturated, or polyunsaturated fatty acids levels had higher HDL-c levels than the non-carriers. These results support the association between the genetic variants on SIDT2 and ABCA1 with HDL-c levels and suggest gene-gene and gene-diet interactions over HDL-c concentrations in Mexican adults. Our findings could be a platform for developing clinical and dietary strategies for improving the health of the Mexican population.

Metabolic Syndrome and Cardiometabolic Risk Factors in the Mixed Hypercholesterolemic Populations with Respect to Gender, Age, and Obesity in Asir, Saudi Arabia

This record study aimed to investigate the prevalence of metabolic syndrome (MetS) profiles regarding sex, age, and obesity for the riskier factor of cardiovascular diseases in a general population in Saudi Arabia. Laboratory and anthropometric measurements were performed on non-specific participants with variant ages and BMI in either sex. Serobiochemical changes were measured for metabolic profiles, i.e., A1C/FSG, TC, TGC, HDLC/LDLC, Vit.D, TSH/T4, Hb, and Cr. The study was applied in a Polyclinic, Abha, Saudi Arabia in 2020 G. The general population showed variable incidences of MetS profiles, such as 69.4% diabetes, 85.5% hypothyroidism, and 92.2% obesity. Hypothyroidism showed a higher incidence in women rather than in men, but men were more dyslipidemic, with higher TGC and LDLC but low HDLC, compared to women. Men <40 Y. showed diabetes and hypothyroidism, but elders were dyslipidemic. Women <40 Y. showed anemia and hypovitaminosis-D but were suffering from hypothyroidism at all ages. Diabetes, hypothyroidism, hypovitaminosis-D, and dyslipidemia were the main MetS components in both overweight and obese participants, and an incidence of more than 50% in each profile was recorded. Diabetes with hypertension was characteristic of obese participants rather than those overweight. About 66.1% of the mixed-hypercholesterolemic cases were diabetic, but 18.9% of the mixed-diabetic participants were hypercholesterolemic. Castelli's risk factors, CRI-I and CRI-II, and atherogenic indices, AIP and AC, were measured for evaluating the cardiac risk in different populations based on the AUC-ROC and cut-off values. Insulin-resistance marker (TyG) was also measured, showing considerable cut-off values for diabetic susceptibility in the lipidemic participants with higher TGC and TC rather than HDLC or LDLC. In conclusion, MetS showed higher susceptibility to sex and age with increased incidence in women rather than men. However, the cardiac risk was more susceptible to men of higher TGC and low HDLC than women. Type 2 Diabetes mellitus (T2DM) was more prominent in both elders (≥40 Y.) than younger ages of either sex. Anemia and deficiency of Vit. D was characteristic of young women (<40 Y.). Hypothyroidism affects young men <40 Y. but was recorded in women of all ages. Both dyslipidemia and diabetes could trigger CVD, showing higher cardiac risk in mixed-hypercholesterolemic men rather than women. Our study strongly suggests that the consumption of unhealthy junk food, tobacco smoking, lack of exercise, and physical inactivity could be conclusive evidence of MetS in the Saudi population.

Familial Hypercholesterolaemia as a Predisposing Factor for Atherosclerosis

Lipid metabolism alterations are an important component of the pathogenesis of atherosclerosis. However, it is now clear that the atherogenesis process involves more than one mechanism, and more than one condition can predispose this condition. Multiple risk factors contribute to the atherosclerosis initiation and define its course. Familial hypercholesterolaemia is a disorder of lipid metabolism that often leads to atherosclerosis development. As is clear from the disease name, the hallmark is the increased levels of low-density lipoprotein cholesterol (LDL-C) in blood. This creates favourable conditions for atherogenesis. In this review, we briefly described the familial hypercholesterolaemia and summarized data on the relationship between familial hypercholesterolaemia and atherosclerosis.

High-Density Lipoprotein and Cardiovascular Disease-Where do We Stand?

Decades of research have shown that high-density lipoprotein cholesterol (HDL-C) levels in humans are associated with atherosclerotic cardiovascular disease (ASCVD). This association is strong and coherent across populations and remains after the elimination of covariates. Animal studies show that increasing HDL particles prevent atherosclerosis, and basic work on the biology of HDL supports a strong biological plausibility for a therapeutic target. This enthusiasm is dampened by Mendelian randomization data showing that HDL-C may not be causal in ASCVD. Furthermore, drugs that increase HDL-C have largely failed to prevent or treat ASCVD.

Cholesterol efflux capacity of HDL was not associated with cognitive decline and brain structures in older people with diabetes mellitus

Aims/Introduction

To examine the association between cholesterol efflux capacity (CEC) of serum high‐density lipoprotein (HDL) and cognitive function and brain structures in older people with diabetes mellitus.

Materials and Methods

Participants of a randomized placebo‐controlled trial of 27‐month vitamin B₁₂ supplementation in older people with diabetes mellitus, which showed no effect on cognition, were further followed up at month 72. Cognitive tests included the Clinical Dementia Rating scale, Neuropsychological Test Battery in memory, executive function and psychomotor speed. Brain magnetic resonance imaging scans were carried out in a subset at baseline, month 27 and month 45. Fasting serum at baseline, month 9, month 27 and month 72 were analyzed for adenosine triphosphate‐binding cassette transporter A1‐mediated CEC of HDL and apolipoprotein A1 (ApoA1).

Results

Serum HDL cholesterol at baseline was associated with better executive and memory function at follow up. Serum ApoA1 was associated with a better memory Z‐score at month 18. Serum CEC and ApoA1 were not associated with Clinical Dementia Rating scale, Neuropsychological Test Battery, hippocampal volume and white matter disease on magnetic resonance imaging at baseline and whole brain atrophy rates. They were also not associated with cognitive function at month 27 and 72 on multilevel modeling. CEC and ApoA1 decreased significantly from baseline to month 27. Faster decliners in CEC had a greater increase in brain peak width of skeletonized mean diffusivity.

Conclusions

Higher serum HDL cholesterol was associated with more favorable changes in memory and executive function in older people with diabetes mellitus. However, this was not due to CEC or ApoA1. A decline in CEC was associated with small vessel disease in the brain.

Influence of the Human Lipidome on Epicardial Fat Volume in Mexican American Individuals

Introduction

Cardiovascular disease (CVD) is the leading cause of mortality worldwide and is the leading cause of death in the US. Lipid dysregulation is a well-known precursor to metabolic diseases, including CVD. There is a growing body of literature that suggests MRI-derived epicardial fat volume, or epicardial adipose tissue (EAT) volume, is linked to the development of coronary artery disease. Interestingly, epicardial fat is also actively involved in lipid and energy homeostasis, with epicardial adipose tissue having a greater capacity for release and uptake of free fatty acids. However, there is a scarcity of knowledge on the influence of plasma lipids on EAT volume.

Aim

The focus of this study is on the identification of novel lipidomic species associated with CMRI-derived measures of epicardial fat in Mexican American individuals.

Methods

We performed lipidomic profiling on 200 Mexican American individuals. High-throughput mass spectrometry enabled rapid capture of precise lipidomic profiles, providing measures of 799 unique species from circulating plasma samples. Because of our extended pedigree design, we utilized a standard quantitative genetic linear mixed model analysis to determine whether lipids were correlated with EAT by formally testing for association between each lipid species and the CMRI epicardial fat phenotype.

Results

After correction for multiple testing using the FDR approach, we identified 135 lipid species showing significant association with epicardial fat. Of those, 131 lipid species were positively correlated with EAT, where increased circulating lipid levels were correlated with increased epicardial fat. Interestingly, the top 10 lipid species associated with an increased epicardial fat volume were from the deoxyceramide (Cer(m)) and triacylglycerol (TG) families. Deoxyceramides are atypical and neurotoxic sphingolipids. Triacylglycerols are an abundant lipid class and comprise the bulk of storage fat in tissues. Pathologically elevated TG and Cer(m) levels are related to CVD risk and, in our study, to EAT volume.

Conclusion

Our results indicate that specific lipid abnormalities such as enriched saturated triacylglycerols and the presence of toxic ceramides Cer(m) in plasma of our individuals could precede CVD with increased EAT volume.

Exome Sequencing Data Analysis and a Case-Control Study in Mexican Population Reveals Lipid Trait Associations of New and Known Genetic Variants in Dyslipidemia-Associated Loci

Background: Plasma lipid levels are a major risk factor for cardiovascular diseases. Although international efforts have identified a group of loci associated with the risk of dyslipidemia, Latin American populations have been underrepresented in these studies.

Objective: To know the genetic variation occurring in lipid-related loci in the Mexican population and its association with dyslipidemia.

Methods: We searched for single-nucleotide variants in 177 lipid candidate genes using previously published exome sequencing data from 2838 Mexican individuals belonging to three different cohorts. With the extracted variants, we performed a case-control study. Logistic regression and quantitative trait analyses were implemented in PLINK software. We used an LD pruning using a 50-kb sliding window size, a 5-kb window step size and a r2 threshold of 0.1.

Results: Among the 34251 biallelic variants identified in our sample population, 33% showed low frequency. For case-control study, we selected 2521 variants based on a minor allele frequency ≥1% in all datasets. We found 19 variants in 9 genes significantly associated with at least one lipid trait, with the most significant associations found in the APOA1/C3/A4/A5-ZPR1-BUD13 gene cluster on chromosome 11. Notably, all 11 variants associated with hypertriglyceridemia were within this cluster; whereas variants associated with hypercholesterolemia were located at chromosome 2 and 19, and for low high density lipoprotein cholesterol were in chromosomes 9, 11, and 19. No significant associated variants were found for low density lipoprotein. We found several novel variants associated with different lipemic traits: rs3825041 in BUD13 with hypertriglyceridemia, rs7252453 in CILP2 with decreased risk to hypercholesterolemia and rs11076176 in CETP with increased risk to low high density lipoprotein cholesterol.

Conclusions: We identified novel variants in lipid-regulation candidate genes in the Mexican population, an underrepresented population in genomic studies, demonstrating the necessity of more genomic studies on multi-ethnic populations to gain a deeper understanding of the genetic structure of the lipemic traits.

Positive association between high-density lipoprotein cholesterol and bone mineral density in U.S. adults: the NHANES 2011-2018

BACKGROUND

Serum lipids are highly inheritable and play a major role in bone health. However, the relationship between high-density lipoprotein cholesterol (HDL-C) and bone mineral density (BMD) remains uncertain. The goal of this study was to see if there was a link between HDL-C levels and BMD in persons aged 20-59.

METHODS

Multivariate logistic regression models were used to determine the link between HDL-C and lumbar BMD using data from the National Health and Nutrition Examination Survey (NHANES) 2011-2018. Generalized additive models and fitted smoothing curves were also used.

RESULTS

The analysis included a total of 10,635 adults. After controlling for various variables, we discovered that HDL-C was positively linked with lumbar BMD. The favorable connection of HDL-C with lumbar BMD was maintained in subgroup analyses stratified by sex and race in women, but not in men, and in blacks, but not in whites. The relationship between HDL-C and lumbar BMD in men and whites was a U-shaped curve with the same inflection point: 0.98 mmol/L.

CONCLUSIONS

In people aged 20 to 59, our research discovered a positive relationship among HDL-C and lumbar BMD. Among males and whites, this relationship followed a U-shaped curve (inflection point: 0.98 mmol/L). HDL-C measurement might be used as a responsive biomarker for detecting osteoporosis early and guiding therapy.

Integrated omics analysis revealed the Tinospora cordifolia intervention modulated multiple signaling pathways in hypertriglyceridemia patients-a pilot clinical trial

Purpose

Hypertriglyceridemia (HTG) is strongly associated with the various types of disease conditions and evolving as epidemics. Hence, it is important to identify molecules that lower the triglyceride and chylomicron levels. Tinospora cordifolia is an illustrious Ayurveda drug, has proved juvenile and immunomodulatory properties.

Methods

Twenty four (24) patients having >499 mg/dL TG and 130-230 mg/dL of cholesterol were randomized and given 100 mL/day (~3.0 g) water extract of T. cordifolia (TCE) for 14 days. Basal parameters were analyzed before and after TC intervention to analyzed primary outcomes. Further, unbiased metabolomics and proteomics profiling was explored to assess the efficacy of TCE in HTG patients.

Results

TCE intervention decreased the levels of triglycerides, and VLDL to 380.45 ± 17.44, and 31.85 ± 5.88, and increased the HDL levels to 47.50 ± 9.05 mg/dL significantly (p < 0.05). Metabolomics analysis identified the significant alteration in 69 metabolites and 72 proteins in plasma of HTG patients. TCE intervention reduced the level of isoprostanes, ROS, BCAA, and fatty acid derivatives, significantly. The annotation databases, Metboanalyst predicted Akt and Rap1 signaling, and ECM-receptor interaction is the most affected in HTG patients. TCE intervention normalized these events by increasing the peroxisome biogenesis and modulating Akt and Rap1 signaling pathway.

Conclusion

T. cordifolia intervention suppresses the baseline in HTG patients. Omics analysis showed that TCE intervention modulates the Akt and Rap signaling, and peroxisome biogenesis to control the cellular switches and signaling pathways. Hence, TCE can be used as a supplement or alternate of standard drugs being used in the management of HTG.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-00985-6.

Genetics and regulation of HDL metabolism

The inverse association between plasma HDL cholesterol (HDL-C) levels and risk for cardiovascular disease (CVD) has been demonstrated by numerous epidemiological studies. However, efforts to reduce CVD risk by pharmaceutically manipulating HDL-C levels failed and refused the HDL hypothesis. HDL-C levels in the general population are highly heterogeneous and are determined by a combination of genetic and environmental factors. Insights into the causes of HDL-C heterogeneity came from the study of monogenic HDL deficiency syndromes but also from genome wide association and Μendelian randomization studies which revealed the contribution of a large number of loci to low or high HDL-C cases in the general or in restricted ethnic populations. Furthermore, HDL-C levels in the plasma are under the control of transcription factor families acting primarily in the liver including members of the hormone nuclear receptors (PPARs, LXRs, HNF-4) and forkhead box proteins (FOXO1-4) and activating transcription factors (ATFs). The effects of certain lipid lowering drugs used today are based on the modulation of the activity of specific members of these transcription factors. During the past decade, the roles of small or long non-coding RNAs acting post-transcriptionally on the expression of HDL genes have emerged and provided novel insights into HDL regulation and new opportunities for therapeutic interventions. In the present review we summarize recent progress made in the genetics and the regulation (transcriptional and post-transcriptional) of HDL metabolism.

Genome-Wide Association Study on Adiponectin-Mediated Suppression of HDL-C Levels in Taiwanese Individuals Identifies Functional Haplotypes in CDH13

CDH13 encodes T-cadherin, which is expressed in the vasculature and cardiac myocytes and is the receptor for hexameric and high-molecular-weight adiponectin. The CDH13 region is the most pivotal locus associated with adiponectin level. Mediation analysis is a method to explore the effect of a third variable, it is assumed that the magnitude of the relationship between the independent and dependent variables will be reduced by statistical adjustment for a third variable. In addition, mediation can further occur in the case when the mediator acts as a pathway-suppressor variable that means a suppression effect may be suggested if the statistical removal of a mediation effect could increase the magnitude of the relationship between the independent and dependent variables. Here, we aimed to explore the suppression effect in a genome-wide association study, and investigate possible mechanisms that may link adiponectin to CDH13 variants and high-density lipoprotein cholesterol (HDL-C). Genome-wide association data for adiponectin and HDL-C were accessible for 2349 Taiwan-biobank participants. The mediation analysis was conducted with the CDH13 lead single nucleotide polymorphism (SNP) rs4783244. The cloned constructs of CDH13 haplotypes (GG and TT) identified from the rs4783244 G/T and rs12051272 G/T SNPs were transiently expressed in HEK293T cells and investigated using the luciferase reporter assay. Genome-wide association analysis showed that HDL-C is significantly associated with variants in CDH13 after adjusting for the adiponectin level. The lead SNP rs4783244 was significantly associated with lower adiponectin levels and exhibited a suppression effect on HDL-C when adiponectin was included as a third factor in the mediation analysis. Luciferase reporter assay results further demonstrated that the GG haplotype increased enhancer activity, whereas the haplotype TT significantly reduced the activity of this enhancer. We present the first evidence of the suppressive role of adiponectin in the genome-wide association between CDH13 and HDL-C. CDH13 may increase the HDL-C levels, and its expression is suppressed by adiponectin.

Population-Based Impact of Smoking, Drinking, and Genetic Factors on HDL-Cholesterol Levels in J-MICC Study Participants

BACKGROUND

Environmental and genetic factors are suggested to exhibit factor-based association with HDL-cholesterol (HDL-C) levels. However, the population-based effects of environmental and genetic factors have not been compared clearly. We conducted a cross-sectional study using data from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study to evaluate the population-based impact of smoking, drinking, and genetic factors on low HDL-C.

METHODS

Data from 11,498 men and women aged 35-69 years were collected for a genome-wide association study (GWAS). Sixty-five HDL-C-related SNPs with genome-wide significance (P < 5 × 10^-8) were selected from the GWAS catalog, and seven representative SNPs were defined, and the population-based impact was estimated using population attributable fraction (PAF).

RESULTS

We found that smoking, drinking, daily activity, habitual exercise, egg intake, BMI, age, sex and the SNPs CETP rs3764261, APOA5 rs662799, LIPC rs1800588, LPL rs328, ABCA1 rs2575876, LIPG rs3786247, and APOE rs429358 were associated with HDL-C levels. The gene-environmental interactions on smoking and drinking were not statistically significant. The PAF for low HDL-C was the highest in men (63.2%) and in rs3764261 (31.5%) of the genetic factors, and the PAFs of smoking and drinking were 23.1% and 41.8%, respectively.

CONCLUSIONS

The present study showed that the population-based impact of genomic factor CETP rs3764261 for low HDL-C was higher than that of smoking and lower than that of drinking.

Living in the Southern Hemisphere: Metabolic Syndrome and Its Components in Amazonian Riverine Populations

The metabolic syndrome (MetS) epidemic is a global challenge. Although developing countries (including Brazil, India, and South Africa) present a higher proportion of deaths by cardiovascular diseases than developed countries, most of our knowledge is from these developed countries. Amazonian riverine populations (ARP), as well as other vulnerable populations of the Southern Hemisphere, share low-income and traditional practices, among other features. This large cross-sectional study of ARP (n = 818) shows high prevalence of hypertension (51%) and obesity (23%). MetS was diagnosed in 38% of participants (especially in women and 60-69 years-old individuals) without the influence of ancestry. Only 7-8% of adults had no cardio-metabolic abnormalities related to MetS. Atherogenic dyslipidemia (low HDL-cholesterol) was generally observed, including in individuals without MetS. Still, slight differences were detected between settings with a clear predominance of hypertension in Tucuruí. Hypotheses on possible genetic influence and factors (nutrition transition and environmental pollutants -mercury) are proposed for future studies. Moreover, a roadmap to MetS progression based on the most prevalent components is provided for the development of tailored interventions in the Amazon (initially, individuals would present low HDL-cholesterol levels, later progressing to increased blood pressure characterizing hypertension, and ultimately reaching MetS with obesity). Our alarming results support the need to improve our knowledge on these vulnerable populations.

Hyperalphalipoproteinemia and Beyond: The Role of HDL in Cardiovascular Diseases

Hyperalphalipoproteinemia (HALP) is a lipid disorder characterized by elevated plasma high-density lipoprotein cholesterol (HDL-C) levels above the 90th percentile of the distribution of HDL-C values in the general population. Secondary non-genetic factors such as drugs, pregnancy, alcohol intake, and liver diseases might induce HDL increases. Primary forms of HALP are caused by mutations in the genes coding for cholesteryl ester transfer protein (CETP), hepatic lipase (HL), apolipoprotein C-III (apo C-III), scavenger receptor class B type I (SR-BI) and endothelial lipase (EL). However, in the last decades, genome-wide association studies (GWAS) have also suggested a polygenic inheritance of hyperalphalipoproteinemia. Epidemiological studies have suggested that HDL-C is inversely correlated with cardiovascular (CV) risk, but recent Mendelian randomization data have shown a lack of atheroprotective causal effects of HDL-C. This review will focus on primary forms of HALP, the role of polygenic inheritance on HDL-C, associated risk for cardiovascular diseases and possible treatment options.

Determinants of penetrance and variable expressivity in monogenic metabolic conditions across 77,184 exomes

Hundreds of thousands of genetic variants have been reported to cause severe monogenic diseases, but the probability that a variant carrier develops the disease (termed penetrance) is unknown for virtually all of them. Additionally, the clinical utility of common polygenetic variation remains uncertain. Using exome sequencing from 77,184 adult individuals (38,618 multi-ancestral individuals from a type 2 diabetes case-control study and 38,566 participants from the UK Biobank, for whom genotype array data were also available), we apply clinical standard-of-care gene variant curation for eight monogenic metabolic conditions. Rare variants causing monogenic diabetes and dyslipidemias display effect sizes significantly larger than the top 1% of the corresponding polygenic scores. Nevertheless, penetrance estimates for monogenic variant carriers average 60% or lower for most conditions. We assess epidemiologic and genetic factors contributing to risk prediction in monogenic variant carriers, demonstrating that inclusion of polygenic variation significantly improves biomarker estimation for two monogenic dyslipidemias.

Case report: 68 yo Chinese-American woman with high HDL-C and ischemic stroke attributed to intracranial atherosclerotic stenosis

Atherosclerotic cardiovascular disease (ASCVD) events are the most common cause of death in the United States and for most individuals who experience these events, may be predicted by risk identification tools. ASCVD risk calculators enable a clinician-patient discussion and the presence of risk-enhancing factors may further inform decision-making with respect to preventive pharmacotherapy, especially statin prescription. In cases where the decision of whether to treat with medicine is unclear, coronary artery calcium scoring by computed tomography offers enhanced risk stratification and may allow both clinicians and patients to feel more at ease with the decision to withhold statin therapy. Despite this thoughtful approach, individual risk may still be underestimated. We present a case of a woman whose family history suggested increased short- and long-term ASCVD risk due to intracranial atherosclerosis, but whose tests suggested a more equivocal indication for treatment. Neither she nor her clinician appreciated the presence of significant enough risk to persevere through minor statin side effects for primary prevention, but she was lucky to have survived without appreciable harm from an acute cerebrovascular event and is now able to pursue an appropriate secondary preventive strategy. We discuss how exceptional characteristics may mislead clinicians, including misperception about lower risk due to gender, East Asian predisposition to intracranial more than coronary atherosclerosis, high levels of high density lipoprotein cholesterol (HDL-C), and CACS = 0.

Associations between TUBB-WWOX SNPs, their haplotypes, gene-gene, and gene-environment interactions and dyslipidemia

In this study, we investigated associations between single nucleotide polymorphisms (SNPs) in the tubulin beta class I (TUBB) and WW domain-containing oxidoreductase (WWOX) genes, gene-gene interactions, and gene-environment interactions and dyslipidemia in the Chinese Maonan ethnic group. Four SNPs (rs3132584, rs3130685, rs2222896, and rs2548861) were genotyped in unrelated subjects with normal lipid levels (864) or dyslipidemia (1129). While 5.0% of Maonan subjects carried the rs3132584TT genotype, none of the Chinese Han in Beijing subjects did. Allele and genotype frequencies differed between the normal and dyslipidemia groups for three SNPs (rs3132584, rs3130685, and rs2222896). rs2222896G allele carriers in the normal group had higher low-density lipoprotein cholesterol and lower high-density lipoprotein cholesterol levels. The rs3132584GG, rs3130685CC+TT, and rs2222896GG genotypes as well as the rs2222896G-rs2548861G and rs2222896G-rs2548861T haplotypes were associated with an elevated risk of dyslipidemia; the rs2222896A-rs2548861T and rs2222896A-rs2548861G haplotypes were associated with a reduced risk of dyslipidemia. Among the thirteen TUBB-WWOX interaction types identified, rs3132584T-rs3130685T-rs2222896G-rs2548861T increased the risk of dyslipidemia 1.371-fold. Fourteen two- to four-locus optimal interactive models for SNP-SNP, haplotype-haplotype, gene-gene, and gene-environment interactions exhibited synergistic or contrasting effects on dyslipidemia. Finally, the interaction between rs3132584 and rs2222896 increased the risk of dyslipidemia 2.548-fold and predicted hypertension.

High-Density Lipoprotein Cholesterol and the Risk of Myocardial Infarction, Stroke, and Cause-Specific Mortality: a Nationwide Cohort Study in Korea

Objective

We aimed to investigate the relationship between high-density lipoprotein cholesterol (HDL-C) level and the risk of myocardial infarction (MI), stroke, and cause-specific mortality.

Methods

Using the Korean National Health Insurance Service-National Sample Cohort, we identified 343,687 subjects (men, 176,243; women, 167,444) aged ≥20 years who underwent health examinations between 2009 and 2012. HDL-C levels were categorized based on the concentration with 10 mg/dL intervals, starting from levels <30 mg/dL, with levels ≥90 mg/dL considered the highest. The endpoints of the study were newly-diagnosed MI, stroke, or mortality. We used the Cox proportional hazards model with restricted cubic splines.

Results

During a median follow-up of 6.0 years, the number of cases of death, MI, and stroke were 6,617, 4,064, and 3,435 in men and 3,677, 2,804, and 2,891 in women, respectively. The risk of all-cause mortality, cancer mortality, other mortality, and stroke was the lowest at HDL-C concentrations of 57-76 mg/dL in the spline curves; inverse associations with increased risk were observed at the lower HDL-C levels. In contrast, the lowest risk of cardiovascular mortality and MI was observed at the extreme high end. In men, there was a significant inverse and graded increase in hazard ratios of all outcomes in the lower HDL-C categories compared to the reference group (50-59 mg/dL). In the higher HDL-C categories, no significant increase in outcomes was observed. Women showed similar trends.

Conclusion

The risk of mortality, MI, and stroke was high at low HDL-C levels in the Korean general population. However, extremely high HDL-C levels were not associated with an increased risk of mortality, MI, and stroke.

Functional Haplotype of LIPC Induces Triglyceride-Mediated Suppression of HDL-C Levels According to Genome-Wide Association Studies

Hepatic lipase (encoded by LIPC) is a glycoprotein in the triacylglycerol lipase family and mainly synthesized in and secreted from the liver. Previous studies demonstrated that hepatic lipase is crucial for reverse cholesterol transport and modulating metabolism and the plasma levels of several lipoproteins. This study was conducted to investigate the suppression effect of high-density lipoprotein cholesterol (HDL-C) levels in a genome-wide association study and explore the possible mechanisms linking triglyceride (TG) to LIPC variants and HDL-C. Genome-wide association data for TG and HDL-C were available for 4657 Taiwan-biobank participants. The prevalence of haplotypes in the LIPC promoter region and their effects were calculated. The cloned constructs of the haplotypes were expressed transiently in HepG2 cells and evaluated in a luciferase reporter assay. Genome-wide association analysis revealed that HDL-C was significantly associated with variations in LIPC after adjusting for TG. Three haplotypes (H1: TCG, H2: CTA and H3: CCA) in LIPC were identified. H2: CTA was significantly associated with HDL-C levels and H1: TCG suppressed HDL-C levels when a third factor, TG, was included in mediation analysis. The luciferase reporter assay further showed that the H2: CTA haplotype significantly inhibited luciferase activity compared with the H1: TCG haplotype. In conclusion, we identified a suppressive role for TG in the genome-wide association between LIPC and HDL-C. A functional haplotype of hepatic lipase may reduce HDL-C levels and is suppressed by TG.

Metabolic syndrome following liver transplantation in nonalcoholic steatohepatitis

Metabolic syndrome is a major clinical disorder involving metabolic dysregulation characterized clinically with features of central obesity, insulin resistance (IR), type 2 diabetes, hypertension, and dyslipidemia. Metabolic syndrome is strongly associated with the rising prevalence nonalcoholic steatohepatitis, a leading indication for orthotopic liver transplantation in the Western world. The presence or recurrence of metabolic syndrome following liver transplantation can contribute to the development and recurrence of nonalcoholic fatty liver disease (NAFLD) in the liver allograft. In this review, we discuss the endogenous and exogenous drivers of post-transplant metabolic syndrome, role of chronic immunosuppression, and the prevalence and clinical significant of post-transplant metabolic syndrome on nonalcoholic steatohepatitis.

Genetic and Non-genetic Determinants of Cardiovascular Disease in South Asians

South Asians (SAs), people from the Indian subcontinent (e.g., India, Pakistan, Bangladesh, Sri Lanka, and Nepal) have a higher prevalence of cardiovascular disease (CVD) and suffer from a greater risk of CVD-associated mortality compared to other global populations. These problems are compounded by the alterations in lifestyles due to urbanization and changing cultural, social, economic, and political environments. Current methods of CV risk prediction are based on white populations that under-estimate the CVD risk in SAs. Prospective studies are required to obtain actual CVD morbidity/mortality rates so that comparisons between predicted CVD risk can be made with actual events. Overwhelming data support a strong influence of genetic factors. Genome-Wide Association Studies (GWAS) serve as a starting point for future genetic and functional studies since the mechanisms of action by which these associated loci influence CVD is still unclear. It is difficult to predict the potential implication of these findings in clinical settings. This review provides a systematic assessment of the risk factors, genetics, and environmental causes of CV health disparity in SAs, and highlights progress made in clinical and genomics discoveries in the rapidly evolving field, which has the potential to show clinical relevance in the near future.

Potential natural inhibitors of xanthine oxidase and HMG-CoA reductase in cholesterol regulation: in silico analysis

Background

Hypercholesterolemia has posed a serious threat of heart diseases and stroke worldwide. Xanthine oxidase (XO), the rate-limiting enzyme in uric acid biosynthesis, is regarded as the root of reactive oxygen species (ROS) that generate atherosclerosis and cholesterol crystals. β-Hydroxy β-methylglutaryl-coenzyme A reductase (HMGR) is a rate-limiting enzyme in cholesterol biosynthesis. Although some commercially available enzyme inhibiting drugs have effectively reduced cholesterol levels, most of them have failed to meet potential drug candidates’ requirements. Here, we have carried out an in-silico analysis of secondary metabolites that have already shown good inhibitory activity against XO and HMGR in a wet lab setup.

Methods

Out of 118 secondary metabolites reviewed, sixteen molecules inhibiting XO and HMGR were selected based on the IC₅₀ values reported in in vitro assays. Further, receptor-based virtual screening was carried out against secondary metabolites using GOLD Protein-Ligand Docking Software, combined with subsequent post-docking, to study the binding affinities of ligands to the enzymes. In-silico ADMET analysis was carried out to explore their pharmacokinetic properties, followed by toxicity prediction through ProTox-II.

Results

The molecular docking of amentoflavone (GOLD score 70.54, ∆G _calc. = − 10.4 Kcal/mol) and ganomycin I (GOLD score 59.61, ∆G _calc. = − 6.8 Kcal/mol) displayed that the drug has effectively bound at the competitive site of XO and HMGR, respectively. Besides, 6-paradol and selgin could be potential drug candidates inhibiting XO. Likewise, n-octadecanyl-O-α-D-glucopyranosyl (6′ → 1″)-O-α-D-glucopyranoside could be potential drug candidates to maintain serum cholesterol. In-silico ADMET analysis has shown that these sixteen metabolites were optimal within the categorical range compared to commercially available XO and HMGR inhibitors, respectively. Toxicity analysis through ProTox-II revealed that 6-gingerol, ganoleucoin K, and ganoleucoin Z are toxic for human use.

Conclusion

This computational analysis supports earlier experimental evidence towards the inhibition of XO and HMGR by natural products. Further study is necessary to explore the clinical efficacy of these secondary molecules, which might be alternatives for the treatment of hypercholesterolemia.

Genetic Variants in Lipid Metabolism Pathways Interact with Diet to Influence Blood Lipid Concentrations in Adults with Overweight and Obesity

INTRODUCTION

The effect of various types of dietary fat on cardiometabolic health continues to be debated, due in part to the high heterogeneity of results following clinical trials investigating the effects of saturated (SFA) and unsaturated fat intake. This variability may be due to genetic differences. Individuals with obesity are at an increased risk for adverse cardiometabolic health and dyslipidemia, and often present with the combined phenotype of elevated triglyceride (TG) and decreased high-density lipoprotein (HDL) cholesterol concentrations. Studying genetic variants relevant to lipid and lipoprotein metabolism can elucidate the mechanisms by which diet might interact with genotype to influence these phenotypes. The objective of this study was to determine relationships of genetic variation, dietary fat intake, and blood lipid concentrations in adults with overweight and obesity.

METHODS

Genomic DNA, blood lipid concentrations (HDL and TG), and 7-day diet records were obtained from 101 adults (25-45 years of age) with overweight or obesity. Resting energy expenditure (REE) was measured using indirect calorimetry and used to determine implausible intakes using a modified Goldberg method (kilocalories/REE). Genetic variants included 23 single-nucleotide polymorphisms (SNPs) from 15 genes in lipid metabolism pathways. Variants were analyzed with dietary fat intake (total fat, SFA, monounsaturated fat [MUFA], and polyunsaturated fat [PUFA]) via regression analyses. All models were adjusted for age, sex, ancestry, visceral adipose tissue mass, and total kilocalorie intake. The Bonferroni correction was applied for multiple comparisons.

RESULTS

Two interactions were detected for TG concentrations. Five gene-diet interactions were associated with HDL concentrations. There was a significant interaction detected between the rs5882 variant of cholesterol-esterase transfer protein (CETP) and MUFA intake to associate with TG concentrations (interaction p = 0.004, R2 = 0.306). Among carriers of the CETP-rs5882 major allele (G), TG concentrations were significantly lower in individuals consuming more than the median MUFA intake (31 g/day) than in those with an intake below the median. Total dietary fat intake interacted with the rs13702 polymorphism of lipoprotein lipase (LPL) to associate with HDL concentrations (interaction p = 0.041, R2 = 0.419), by which individuals with the risk allele (G) had significantly higher HDL concentrations when consuming a higher-fat diet (>92 g/day) than those with a lower-fat diet (56 ± 3 vs. 46 ± 2 mg/dL, p = 0.033).

CONCLUSIONS

Interactions between dietary intake and genes in lipid metabolism pathways were found to be associated with blood lipid concentrations in adults with overweight and obesity. Fatty acid intake may not modulate blood lipid concentrations uniformly across all individuals. Additional research is needed to determine the biological causes of individual variability in response to dietary intake. Understanding the influence of nutrigenetic interactions on dyslipidemia can aid in the development and implementation of personalized dietary strategies to improve health.

Carotid artery intima-media thickness, HDL cholesterol levels, and gender associated with poor visual acuity in patients with branch retinal artery occlusion

PURPOSE

To investigate factors associated with poor visual acuity (VA) in branch retinal artery occlusion (BRAO).

METHODS

This was a retrospective cross-sectional study of 72 eyes with BRAO of 72 patients. For statistical comparison, we divided the patients into worse-VA (decimal VA < 0.5) and better-VA (decimal VA > = 0.5) groups. We examined the association of clinical findings, including blood biochemical test data and carotid artery ultrasound parameters, with poor VA.

RESULTS

Median age, hematocrit, hemoglobin and high-density lipoprotein (HDL) differed significantly between the groups (P = 0.018, P < 0.01, P < 0.01, and P = 0.025). There was a tendency towards higher median IMT-Bmax in the worse-VA group (worse-VA vs. better-VA: 2.70 mm vs. 1.60 mm, P = 0.152). Spearman's rank correlation test revealed that logMAR VA was significantly correlated to IMT-Bmax (rs = 0.31, P < 0.01) and IMT-Cmax (rs = 0.24, P = 0.035). Furthermore, logMAR VA was significantly correlated to HDL level (rs = -0.33, P < 0.01). Multivariate logistic regression analysis revealed that IMT-Bmax (odds ratio [OR] = 2.70, P = 0.049), HDL level (OR = 0.91, P = 0.032), and female gender (OR = 15.63, P = 0.032) were independently associated with worse VA in BRAO.

CONCLUSIONS

We found that increased IMT-Bmax, decreased HDL, and female sex were associated with poor VA in BRAO patients. Our findings might suggest novel risk factors for visual dysfunction in BRAO and may provide new insights into the pathomechanisms underlying BRAO.

Effect of Bariatric Surgery on High-Density Lipoprotein (HDL) Cholesterol in Non-diabetic Patients with Severe Obesity

BACKGROUND

This study evaluated changes in serum high-density lipoprotein cholesterol (HDL-C) induced by laparoscopic bariatric surgery (BS) in non-diabetic obese subjects with low (L-HDL-C) or normal (N-HDL-C) levels of HDL-C. We assessed whether increased HDL-C is associated with weight loss, serum non-HDL cholesterol (non-HDL-C), serum triglycerides (TG), and physical activity (PA) before and 6 and 15 months after BS.

METHODS

In this prospective cohort study, 71 subjects undergoing BS (42 by Roux-en-Y gastric bypass and 29 by sleeve gastrectomy) were evaluated for the % Excess Weight Loss (%EWL), waist circumference (WC), serum levels of glucose, glycosylated hemoglobin, TG, HDL-C, non-HDL-C, and LDL-C, and the degree, time, and energy expenditure related to PA. The short version of the International Physical Activity Questionnaire was used to assess PA.

RESULTS

Levels of HDL-C significantly increased 15 months after BS (p < 0.001) in subjects with low (p < 0.001) or normal (p = 0.017) values at baseline. A similar %EWL, decrease in WC, glucose, non-HDL-C, and LDL-C levels and increase in energy expenditure related to PA, was observed in both groups (L-HDL-C and N-HDL-C) at 15 months after BS. However, the L-HDL-C group presented greater decrease in TG levels compared with N-HDL-C group (p = 0.004). In subjects with increased HDL-C 15 months after BS, there was an association between this increase and the %EWL (p = 0.030), but there was no association with the change in PA.

CONCLUSIONS

Irrespective of PA after BS, subjects with low and normal HDL-C levels at baseline showed an increase in HDL-C after BS, and this increase was associated with %EWL induced by BS.

Dietary fish and ω-3 polyunsaturated fatty acids are associated with leukocyte ABCA1 DNA methylation levels

OBJECTIVES

A diet rich in fish and ω-3 polyunsaturated fatty acids (PUFAs) has been thought to reduce the risk for cardiovascular disease (CVD). The beneficial effects of fish oil and ω-3 PUFA on CVD can be mediated by epigenetic status of the genes associated with lipid metabolism and inflammation. The aim of this study was to investigate whether dietary fish and fatty acid (FA) intakes are associated with leukocyte ATP-binding cassette transporter A1 (ABCA1) DNA methylation levels in a Japanese population.

METHODS

This cross-sectional study included 298 adults (137 men and 161 women) without clinical history of CVD or cancer. The pyrosequencing method was used to measure leukocyte ABCA1 DNA methylation levels. Dietary fish and FA intakes were assessed based on the validated food frequency questionnaire.

RESULTS

Mean ABCA1 DNA methylation levels were significantly lower in the highest fish intake groups (≥5-6/wk) compared with the lowest intake group (≤1-2/wk; P = 0.004). In multivariable linear regression analyses, higher dietary intake of ω-3 PUFAs and ω-3 highly unsaturated fatty acids was significantly associated with decreased levels of ABCA1 DNA methylation (P = 0.001 and 0.005); whereas no significant associations were seen between intake of dietary saturated fatty acid, monounsaturated fatty acid, and ω-6 PUFAs and ABCA1 DNA methylation.

CONCLUSION

Higher dietary fish and ω-3 PUFA intake were associated with lower ABCA1 DNA levels in a Japanese population. The present results may bring potential insights on biological mechanisms underlying the protective effects of dietary fish and ω-3 PUFA intakes on CVD.

Increased risk of hypercholesterolemia in a French and Lebanese population due to an interaction between rs2569190 in CD14 and gender

RATIONALE

Since identifying gender-specific genetic associations may have a significant impact on public health, we studied the interaction between rs2569190 in CD14 (cluster of differentiation 14) and gender in relation to the lipid traits in two independent populations.

METHODS

We first tested the interaction in a discovery population (SFS, n = 956), then replicated it in an independent population (LGP, n = 460), followed by a meta-analysis (n = 1,416). Finally, stratification according to gender was conducted to test the association between rs2569190 and lipid traits. Binary multiple logistic regression models were used while correcting for many confounders. Power calculations were also performed.

RESULTS

An interaction between rs2569190 and gender, which increased the risk of total cholesterol levels in SFS, was found (OR = 2.151 and P = 0.05). This interaction was further replicated in the LGP (OR = 1.353 and P < 0.001), and the meta-analysis showed an overall significant interaction (OR = 1.436 and P_meta = 0.02). Similarly, the meta-analysis showed an overall significant positive effect (OR = 1.204 and P_meta = 0.004) for low-density lipoprotein cholesterol levels. Overall, 1,416 patients were evaluated, and the statistical heterogeneity was low, with I² estimates ranging between 0% and 22.2%. In contrast, rs2569190 in CD14 did not show any significant interaction with gender influencing high-density lipoprotein levels and triglycerides levels in both populations.

CONCLUSION

An interaction between rs2569190 in CD14 and gender increased the risk of hypercholesterolemia in two independent populations with a gender-specific effect in males.

Lipase C, Hepatic Type -250A/G (rs2070895) Variant Enhances Carotid Atherosclerosis in Normolipidemic and Asymptomatic Individuals from Brazil

The common genetic variant in the promoter region of the hepatic lipase gene [LIPC -250G/A(rs2070895)] has an ambiguous association with cardiovascular disease. In this context, our study was performed to identify the relationships between the rs2070895 with carotid atherosclerosis, plasma lipids, and parameters of reverse cholesterol transport. A total of 285 normolipidemic and asymptomatic participants from an initial sample of 598,288 individuals (inclusion criteria: LDL-C ≤130 mg/dL and triglycerides ≤150 mg/dL; age: 20-75 years, both genders; confirmation of clinical, anthropometric and laboratory data; attended all visits; DNA was achieved to perform genetic analysis) were enrolled and the rs2070895 variant was genotyped by TaqMan® OpenArray® Plataform. Carotid intima-media thickness and the screening of atherosclerotic plaques were determined by B-mode ultrasonography. The rs2070895 genotype frequencies were 0.44, 0.41, and 0.15 (GG, GA, and AA, respectively). Logistic regression analysis showed that the risk of having plaques was increased in participants carrying the AA or AG genotypes (OR = 3.90; 95% CI = 1.54-10.33), despite an increase in high-density lipoprotein cholesterol levels, HDL diameter and apolipoprotein A-I, as compared to the GG genotype. Hepatic lipase and endogenous lecithin cholesterol acyl transferase activities were reduced (38% and 19%, respectively) and lipoprotein lipase was increased by 30% (AA vs GG). Our results provide evidence that the AA or AG genotypes of the rs2070895 were associated with carotid atherosclerosis in apparently healthy participants, probably as a consequence of reduced reverse cholesterol transport and accumulation of HDL subfraction 2 rich in triglycerides and depleted in cholesteryl esters that could become dysfunctional.

Associations between cardiovascular disease, cancer, and very low high-density lipoprotein cholesterol in the REasons for Geographical and Racial Differences in Stroke (REGARDS) study

Aims

Relatively little is known about the health outcomes associated with very low plasma concentrations of high-density lipoprotein cholesterol (HDL-C) mainly because of the small numbers of individuals with such extreme values included in clinical trials. We, therefore, investigated the association between low and very low HDL-C concentration at baseline and incident all-cause-mortality, death from malignant disease (i.e. cancer), and with fatal or non-fatal incident coronary heart disease (CHD) in individuals from the Reasons for Geographical And Racial Differences in Stroke (REGARDS) study.

Methods and results

Analysis was based on 21 751 participants from the REGARDS study who were free of CHD, other cardiovascular disease, and cancer at baseline and were categorized by baseline HDL-C into <30 mg/dL (very low), 30-<40 mg/dL (low), and ≥40 mg/dL (reference). A series of incremental Cox proportional hazards models were employed to assess the association between the HDL-C categories and outcomes. Statistical analysis was performed using both complete case methods and multiple imputations with chained equations. After adjustment for age, race, and sex, the hazard ratios (HRs) comparing the lowest and highest HDL-C categories were 1.48 [95% confidence interval (CI) 1.28-1.73] for all-cause mortality, 1.35 (95% CI 1.03-1.77) for cancer-specific mortality and 1.39 (95% CI 0.99-1.96) for incident CHD. These associations became non-significant in models adjusting for demographics, cardiovascular risk factors, and treatment for dyslipidaemia. We found evidence for an HDL paradox, whereby low HDL (30-<40 mg/dL) was associated with reduced risk of incident CHD in black participants in a fully adjusted complete case model (HR 0.63; 95% CI 0.46-0.88) and after multiple imputation analyses (HR 0.76; 95% CI 0.58-0.98). HDL-C (<30 mg/dL) was significantly associated with poorer outcomes in women for all outcomes, especially with respect to cancer mortality (HR 2.31; 95% CI 1.28-4.16) in a fully adjusted complete case model, replicated using multiple imputation (HR 1.81; 95% CI 1.03-3.20).

Conclusion

Low HDL-C was associated with reduced risk of incident CHD in black participants suggesting a potential HDL paradox for incident CHD. Very low HDL-C in women was significantly associated with cancer mortality in a fully adjusted complete case model.