Low Plasma High-density Lipoprotein Cholesterol Research Articles

Cardiovascular outcomes in patients with homozygous familial hypercholesterolaemia on lipoprotein apheresis initiated during childhood: long-term follow-up of an international cohort from two registries

Homozygous familial hypercholesterolaemia (HoFH) is a rare genetic disease characterised by extremely high plasma LDL cholesterol from birth, causing atherosclerotic cardiovascular disease at a young age. Lipoprotein apheresis in combination with lipid-lowering drugs effectively reduce LDL cholesterol, but long-term health outcomes of such treatment are unknown. We aimed to investigate the long-term cardiovascular outcomes associated with lipoprotein apheresis initiated in childhood or adolescence. In this cohort study, data were drawn from the HoFH International Clinical Collaboration (HICC) and the international registry for Children with Homozygous Hypercholesterolemia on Lipoprotein Apheresis (CHAIN). An overall cohort included patients diagnosed with HoFH aged 0-18 years who were alive and in follow-up between Jan 1, 2010, and Nov 8, 2021, and whose high plasma LDL cholesterol concentrations made them eligible for lipoprotein apheresis. To compare cardiovascular outcomes, patients who initiated lipoprotein apheresis in childhood (lipoprotein apheresis group) and patients who only received lipid-lowering drugs (pharmacotherapy-only group) were matched by sex and untreated plasma LDL cholesterol concentrations. The primary outcome was a composite of cardiovascular death, myocardial infarction, ischaemic stroke, percutaneous coronary intervention, coronary artery bypass grafting, aortic valve replacement, peripheral artery disease, carotid endarterectomy, angina pectoris, and supra-aortic or aortic stenosis (collectively referred to as atherosclerotic cardiovascular disease), for which survival analyses were performed in the matched cohort. Cox regression analyses were used to compare disease-free survival between cohorts and to calculate hazard ratio (HR) and 95% CI adjusted for sex, age at diagnosis, untreated plasma LDL cholesterol concentration, and number of lipid-lowering therapies other than lipoprotein apheresis. The overall cohort included 404 patients with a median age at diagnosis of 6·0 years (IQR 3·0-9·5) and median untreated plasma LDL cholesterol of 17·8 mmol/L (14·7-20·8). The matched cohorts included 250 patients (125 patients per group), with a median untreated LDL cholesterol of 17·2 mmol/L (14·8-19·7). Mean reduction in plasma LDL cholesterol concentrations between baseline and final follow-up was greater in the lipoprotein apheresis group (-55% [95% CI -60 to -51] vs -31% [-36 to -25]; p<0·0001). Patients in the lipoprotein apheresis group had longer atherosclerotic cardiovascular disease-free survival (adjusted HR 0·52 [95% CI 0·32-0·85]) and longer cardiovascular death-free survival (0·0301 [0·0021-0·4295]). Cardiovascular death was more common in the pharmacotherapy-only group than in the lipoprotein apheresis group (ten [8%] vs one [1%]; p=0·010), whereas median age at coronary artery bypass grafting was lower in the lipoprotein apheresis group than in the pharmacotherapy-only group (15·0 years [IQR 12·0-24·0] vs 30·5 years [19·0-33·8]; p=0·037). Among patients with HoFH, lipoprotein apheresis initiated during childhood and adolescence is associated with reduced long-term risk of atherosclerotic cardiovascular disease and death, and clear benefits of early initiation of high-frequency treatment on reducing plasma cholesterol were found. Consensus recommendations are now needed to guide more widespread and timely use of lipoprotein apheresis for children with HoFH, and research is required to further optimise treatment and ensure benefits of early and aggressive treatment delivery are balanced against effects on quality of life. Amsterdam University Medical Centers, Location Academic Medical Center; Perelman School of Medicine at the University of Pennsylvania; European Atherosclerosis Society; and the US National Heart, Lung, and Blood Institute, National Institutes of Health.

Recapitulating familial hypercholesterolemia in a mouse model by knock-in patient-specific LDLR mutation.

Familial hypercholesterolemia (FH) is one of the most prevalent monogenetic disorders leading to cardiovascular disease (CVD) worldwide. Mutations in Ldlr, encoding a membrane-spanning protein, account for the majority of FH cases. No effective and safe clinical treatments are available for FH. Adenine base editor (ABE)-mediated molecular therapy is a promising therapeutic strategy to treat genetic diseases caused by point mutations, with evidence of successful treatment in mouse disease models. However, due to the differences in the genomes between mice and humans, ABE with specific sgRNA, a key gene correction component, cannot be directly used to treat FH patients. Thus, we generated a knock-in mouse model harboring the partial patient-specific fragment and including the Ldlr W490X mutation. LdlrW490X/W490X mice recapitulated cholesterol metabolic disorder and clinical manifestations of atherosclerosis associated with FH patients, including high plasma low-density lipoprotein cholesterol levels and lipid deposition in aortic vessels. Additionally, we showed that the mutant Ldlr gene could be repaired using ABE with the cellular model. Taken together, these results pave the way for ABE-mediated molecular therapy for FH.

Salivary cholesterol level does not reflect cholesterolemia in children with heterozygous familial hypercholesterolemia

ObjectivesHeterozygous familial hypercholesterolemia is a common genetic disease responsible for premature atherosclerosis. Therefore, early diagnosis and treatment are recommended to reduce cardiovascular risk. Usually, the screening is based on high plasma LDL-cholesterol. In children, blood testing is often an obstacle for screening. This study aims to evaluate the relevance of a salivary non-invasive LDL dosage in heterozygous familial hypercholesterolemia in a pediatric population. Materials and methodsProspective, case control, monocentric study comparaing the salivary cholesterol of 30 heterozygous familial hypercholesterolemia pediatric patients and 30 healthy age-matched controls with two different enzymatic kits (Amplite™ kit - AAT Bioquest® and Total Cholesterol Assay kit - CELL BIOLABS®, Inc). ResultsWhile the median serum total-cholesterol was significantly different in control and heterozygous familial hypercholesterolemia patients as expected, the median salivary cholesterol concentration was similar between the two groups and 1000 times lower than in serum. No correlation was found between salivary and serum cholesterol concentrations. ConclusionAlthough cholesterol is detectable in saliva, our study suggests that the low salivary cholesterol concentrations result mostly from variable gingival bleeding, precluding any reliable use for Heterozygous Familial Hypercholesterolemia screening in children.

#2768 DIFFERENT EFFECTS OF HYPOXIA-INDUCIBLE FACTOR PROLYL HYDROXYLASE INHIBITORS ON SERUM LIPIDS LEVELS IN HEMODIALYSIS PATIENTS

Abstract Background The activity of hypoxia-inducible factor (HIF), an oxygen-sensitive transcription factor involved in erythropoiesis, is regulated by HIF-prolyl hydroxylases. With reduced oxygen tension, the activity of these enzymes is suppressed, resulting in increased erythropoiesis. Chen et al. reported that the decrease in that total cholesterol (TC) was greater with roxadustat than with epoetin alfa, as was the decrease in low density lipoprotein-cholesterol (LDL-C) in patients undergoing dialysis [1]. Csiky et al. reported roxadustat was superior to erythropoiesis-stimulating agent (ESA) in decreasing LDL-C levels from baseline in patients on dialysis [2]. Roxadustat is an oral HIF-prolyl hydroxylase inhibitor (HIF-PHI) developed for dialysis-dependent chronic kidney disease (CKD) anemia. While the impact of HIF-PHI on mean hemoglobin (Hb) change in patients on hemodialysis (HD) has been investigated [1], its effects on serum lipid levels have yet to be explored. Clarifying such effects is particularly important because HD patients usually have lower plasma high-density lipoprotein-cholesterol (HDL-C) levels than healthy individuals. Low HDL-C levels are associated with an increased risk of death in HD patients. The effects of HIF-PHIs on dyslipidemia in patients on HD are unclear. This study aimed to investigate the effects of HIF-PHIs on serum lipid levels in HD patients. Methods We investigated the effect of HIF-PHIs in three groups by measuring the levels Hb, serum TC, LDL-C, HDL-C, triglycerides (TG), iron, total iron-binding capacity (TIBC), transferrin saturation (TSAT), ferritin. Study 1: We evaluated the efficacy of roxadustat in 13 patients (1 female and 12 males) with HD-dependent CKD anemia and dyslipidemia over 24 weeks. Study 2: We evaluated the efficacy of daprodustat in 9 patients (2 females and 7 males) with HD-dependent CKD anemia and dyslipidemia over 24 weeks. Study 3: We evaluated the efficacy of enarodustat in 15 patients (3 females and 12 males) with HD-dependent CKD anemia and dyslipidemia over 12 weeks. Results Study 1: The mean age and mean HD vintage were 77.7 and 6.6 years, respectively. After roxadustat treatment, the mean Hb values (from 10.4 to 10.7 g/dL) did not significantly change. There were no significant changes in mean serum iron, TG, ferritin. However, the following parameters showed a significant decrease: mean TC (from 138.4 to 106.6 mg/dL, p = 0.0002), LDL-C (77.7 to 53.8 mg/dL, p = 0.0002), HDL-C (from 43.3 to 35.9 mg/dL, p = 0.0005), and TSAT (from 32.6 to 31.2%, p = 0.0479). There was a significant increases in the mean TIBC (from 220.5 to 265.1 μg/dL, p = 0.0002). Study 2: The mean age and mean HD vintage were 74.6 and 3.2 years, respectively. After daprodustat treatment, the mean Hb values did not significantly change. There were no significant changes in the mean TC, LDL-C, TG, TSAT, ferritin. However, the mean HDL-C levels showed a statistically significant decrease (from 50.4 to 45.3 mg/dL, p = 0.0117). Furthermore, there were significant increases in the serum iron level (from 72.5 to 89.1 μg/dL, p = 0.0078) and the mean TIBC level (from 229.7 to 272.8 μg/dL, p = 0.0039). Study 3: The mean age and mean HD vintage were 69.3 and 8.9 years, respectively. After enarodustat treatment, the mean Hb values did not significantly change. There were no significant changes in the mean TC, LDL-C, HDL-C, TG, TSAT, ferritin, iron. There was a significant increase in the mean TIBC (from 230.0 to 259.4 μg/dL, p = 0.0151). Conclusions We found that HIF-PHIs had different effects on serum lipids levels in HD patients. Roxadustat treatment improved iron metabolism stabilized Hb levels, and significantly decreased LDL-C levels. Daprodustat and enarodustat treatment improved iron metabolism, maintained stable Hb levels.

Identification of pathogenic variants in the Brazilian cohort with Familial hypercholesterolemia using exon-targeted gene sequencing

Familial hypercholesterolemia (FH) is a monogenic disease characterized by high plasma low-density lipoprotein cholesterol (LDL-c) levels and increased risk of premature atherosclerotic cardiovascular disease. Mutations in FH‐related genes account for 40% of FH cases worldwide. In this study, we aimed to assess the pathogenic variants in FH-related genes in the Brazilian FH cohort FHBGEP using exon-targeted gene sequencing (ETGS) strategy. FH patients (n = 210) were enrolled at five clinical sites and peripheral blood samples were obtained for laboratory testing and genomic DNA extraction. ETGS was performed using MiSeq platform (Illumina). To identify deleterious variants in LDLR, APOB, PCSK9, and LDLRAP1, the long-reads were subjected to Burrows-Wheeler Aligner (BWA) for alignment and mapping, followed by variant calling using Genome Analysis Toolkit (GATK) and ANNOVAR for variant annotation. The variants were further filtered using in-house custom scripts and classified according to the American College Medical Genetics and Genomics (ACMG) guidelines. A total of 174 variants were identified including 85 missense, 3 stop-gain, 9 splice-site, 6 InDel, and 71 in regulatory regions (3′UTR and 5′UTR). Fifty-two patients (24.7%) had 30 known pathogenic or likely pathogenic variants in FH-related genes according to the American College Medical and Genetics and Genomics guidelines. Fifty-three known variants were classified as benign, or likely benign and 87 known variants have shown uncertain significance. Four novel variants were discovered and classified as such due to their absence in existing databases. In conclusion, ETGS and in silico prediction studies are useful tools for screening deleterious variants and identification of novel variants in FH-related genes, they also contribute to the molecular diagnosis in the FHBGEP cohort.

Different clinical phenotypes of a pair of siblings with familial hypercholesterolemia: a case report and literature review

BackgroundFamilial hypercholesterolemia (FH) leads to high plasma low-density lipoprotein cholesterol (LDL-C) levels and early cardiovascular morbidity and mortality. We treated a pair of siblings with FH. The cardiovascular manifestations in the proband were more severe than those in his elder sister, although they had almost similar LDL-C levels, ages, and lifestyles. Herein, we report the cases of this family to explore the possible causes of clinical phenotypic differences within the same genetic background.Case presentationWe treated a 27-year-old male patient and his 30-year-old sister, both with FH. The coronary angiogram in the male patient revealed 80, 70, and 100% stenosis of the initial, distal right coronary artery branch, and left anterior descending branch, respectively, whereas his sister had almost no coronary stenosis. We treated them accordingly and performed family screening. We found that the LDL-C/particle discordance of the proband is much greater than that of his elder sister. In addition, the average size of LDL-C particle in the proband was smaller than that in his sister.ConclusionsPatients with FH have a much higher risk of premature atherosclerotic cardiovascular disease, but the clinical manifestations are heterogeneous. The smaller LDL particle size may be the underlying cause for different clinical outcomes in this pair of FH cases and be a potential novel indicator for predicting the prognosis of FH.

Effects of the Ketogenic Diet on Metabolic Syndrome

The global prevalence of obesity and metabolic syndrome and its pathophysiologic sequela are currently approaching epidemic proportions, with unacceptable levels in much of Westernized and economically developed society. The clinical stigmata of metabolic syndrome typically include the comorbidities of obesity, hypertension, non-insulin dependent diabetes, and hyperlipidemia with decreased plasma high density lipoprotein concentrations. In addition, a common finding of hyperinsulinemia and insulin resistance typical of high carbohydrate diets often accompanies the syndrome. The incorporation of the insulin sparing ketogenic diet as a dietary strategy for the treatment of metabolic syndrome may bring about improvements in insulin action and substrate utilization in peripheral tissues with at least a partial if not significant resolution of the syndrome. Thus, the ketogenic diet in addition to adaptations toward a healthy lifestyle and pharmacologic therapies have been explored as potential mechanisms to resolve the pathophysiologic sequela of obesity and metabolic syndrome and their impact on the delivery of healthcare. Metabolic syndrome (MetS) is a condition defined as a clustering of risk factors that is strongly associated with obesity, heart disease, and diabetes [22]. It has recently been estimated that the global prevalence of MetS has reached epidemic levels including the U.S.A., where it has been estimated that 20% to 25% of the adult global population meets the diagnostic criterion for MetS [3], which may be established when at least three of the five primary risk factors are present. The risk factors include a large waistline (abdominal or visceral obesity), high plasma triglyceride levels, low plasma HDL cholesterol concentrations, elevated blood pressure, and fasting hyperglycemia. The standard and most effective treatments for MetS to date have been incorporation of lifestyle changes, with dietary interventions being one of the major effective lifestyle modifications utilized to treat both obesity and MetS [14];[41]. The Ketogenic Diet (KD) is one dietary intervention that may have the potential to improve MetS risk factors. Historically, one of the primary uses of the KD has been to treat epilepsy, however, there is substantial evidence that it may also help to improve other conditions and illnesses, including obesity and MetS [30]; [48]; [35]. Despite this potential, certain dietary misconceptions may have prevented or slowed further research on the KD applications to weight control and use of the KD, particularly the emergence of the national dietary guidelines that have now promoted a low-fat, high-carbohydrate diet for several decades [18]; [51]; [52]. The purpose of this paper is to conduct a review of the literature regarding MetS, the KD, and the implications of the KD as a treatment for obesity and MetS. Existing research is systematically reviewed regarding the KD’s potential to address MetS and MetS risk factors. The results of the review indicate the validity of the diet and the need for further research on the KD and its potential to address the benefits, potential risks and clinical efficacy of the KD on reducing the pathophysiologic sequalae of obesity and MetS. MetS = Metabolic Syndrome, KD = ketogenic diet, KB = ketone bodies, including metabolic remnants acetoacetate (AcAc),3-beta-hydroxybutyrate (3HB), and acetone, PSMF = Protein Sparing Modified Fast, HDL, HDL-C= plasma high density cholesterol lipoprotein, LDL, LDL-C = low density cholesterol lipoprotein, TG, TRIG = plasma triglycerides, CRP = C-reactive protein, GLUT4 = Glucose Transporter 4, and insulin-linked cellular entity, ATP = Adenosine tri-phosphate, a high energy phosphate, CCK = cholecystokinin, CR = calorie restricted diet, LFD = low fat diet, LCKD = low calorie ketogenic diet, BP = blood pressure; SBP = systolic blood pressure; DBP = diastolic blood pressure, A(1c) = glycosylated hemoglobin fraction, NHLBI = National Heart, Lung and Blood Institute of the National Institutes of Health

The Effect of Pre-transplant Lipid Profile on Post-transplant Hepatocellular Carcinoma Recurrence: Retrospective Single-Center Analysis.

Plasma lipids have been shown to relate to tumor biology. We aimed to analyze the effect of pre-transplant plasma lipid profiles on post-transplant tumor recurrence in patients with hepatocellular carcinoma and to identify any possible relationship between the pre-transplant lipid profile with maximum tumor diameter, number of tumor nodules, tumor differentiation, portal vein invasion, or serum biomarker levels. Patients with hepatocellular carcinoma who underwent liver transplants between 2006 and 2021 had data collected pro- spectively and were analyzed retrospectively. Patients who did not have lipid profile data before transplant and whose post-transplant follow-up period was <90 days were excluded. Patients who had pre-transplant plasma lipid data and whose post-transplant follow-up period was >90 days were included in this study (n = 254). Lower high-density lipoprotein cholesterol levels were found to be significantly associated with post-Tx recurrence (38 vs 29.5, P < .001) and were also significantly associated with macroscopic portal vein thrombosis (39 vs 30.4, P < .021). There was no significant association between plasma lipids and tumor differentiation. Higher high-density lipoprotein cholesterol levels were significantly asso- ciated with good overall and disease-free survivals (P = .024 and P = .001). Pre-transplant low plasma high-density lipoprotein cholesterol levels were significantly associated with portal vein throm- bosis and poor post-transplant overall and disease-free survivals.

Familial hypercholesterolemia in China requires greater efforts

Familial hypercholesterolemia in China requires greater efforts

Sex-dependent relationship of C-reactive protein levels with HDL-cholesterol and HDL-phospholipid concentrations in children

Obesity has been consistently associated with inflammation but the influence of HDL on this association remains under study. Our study analyzes the influence of obesity-related parameters in the relationship of high-sensitivity C-reactive protein (hs-CRP) with HDL-cholesterol and HDL-phospholipid in male and female adolescents. The study sample population comprised 350 males and 401 females aged 12 to 16 years. Information regarding anthropometric parameters, HDL-cholesterol, HDL-phospholipid, adiponectin, leptin, insulin, and hs-CRP concentrations was available. hs-CRP levels were inversely related to HDL-cholesterol and HDL-phospholipid in males but not in females, and were positively related to leptin concentrations in both sexes but were not related to adiponectin levels. In regression analyses, HDL-phospholipid and leptin appeared significantly associated to hs-CRP in males in a model explaining 14.3% of hs-CRP variation. In females, only leptin appeared related to hs-CRP concentrations. After adjusting by leptin and adiponectin, males in the highest hs-CRP tertile showed significantly lower levels of HDL-cholesterol and HDL-phospholipid than those in tertiles 1 and 2, while no significant differences in HDL-cholesterol and HDL-phospholipid concentrations by hs-CRP tertile were observed in females. In summary, high hs-CRP levels were associated with lower plasma HDL-cholesterol and HDL-phospholipid concentrations in male adolescents irrespective of adipokines, while in females, HDL-related parameters are not associated with hs-CRP concentrations.

Familial Hypercholesterolemia Prevalence Among Ethnicities-Systematic Review and Meta-Analysis.

Background: Heterozygous familial hypercholesterolemia (FH) is a common genetic disorder leading to premature cardiovascular disease and death as a result of lifelong high plasma low-density lipoprotein cholesterol levels, if not treated early in life. The prevalence of FH varies between countries because of founder effects, use of different diagnostic criteria, and screening strategies. However, little is known about differences in FH prevalence according to ethnicity. We aimed to investigate the ethnic distribution of FH in diverse populations and estimate the prevalence of FH according to ethnicity. Methods: We performed a systematic review and meta-analysis, searching PubMed and Web of Science for studies presenting data on the prevalence of heterozygous FH among different ethnicities in non-founder populations. Studies with more than 100 individuals, relevant data on prevalence, ethnicity, and using the Dutch Lipid Clinical Network Criteria, Simon Broome, Making Early Diagnosis Prevents Early Death, genetic screening, or comparable diagnostic criteria were considered eligible for inclusion. Results: Eleven general population studies and two patient studies were included in a systematic review and 11 general population studies in a random-effects meta-analysis. The overall pooled FH prevalence was 0.33% or 1:303 in 1,169,879 individuals (95% confidence interval: 0.26–0:40%; 1:385–1:250). Included studies presented data on six ethnicities: black, Latino, white, Asian, brown, and mixed/other. Pooled prevalence was estimated for each group. The highest prevalence observed was 0.52% or 1:192 among blacks (0.34–0.69%; 1:294–1:145) and 0.48% or 1:208 among browns (0.31–0.74%; 1:323–1:135) while the lowest pooled prevalence was 0.25% or 1:400 among Asians (0.15–0.35; 1:500–1:286). The prevalence was 0.37% or 1:270 among Latino (0.24–0.69%; 1:417–1:145), 0.31% or 1:323 among white (0.24–0.41%; 1:417–1:244), and 0.32% or 1:313 among mixed/other individuals (0.13–0.52%; 1:769–1:192). Conclusion: The estimated FH prevalence displays a variation across ethnicity, ranging from 0.25% (1:400) to 0.52% (1:192), with the highest prevalence seen among the black and brown and the lowest among the Asian individuals. The differences observed suggest that targeted screening among subpopulations may increase the identification of cases and thus the opportunity for prevention.

HDL associates with insulin resistance and beta-cell dysfunction in South Asian families at risk of type 2 diabetes

Dyslipidemia precedes type 2 diabetes (T2D) and worsens with increasing glucose intolerance. First degree relatives of T2D patients have an increased risk to develop dyslipidemia and glucose intolerance. The aim of the present study was to assess the relation between the development of dyslipidemia and glucose intolerance in first-degree relatives of T2D patients. Fasting lipoprotein profiles were determined by density gradient ultracentrifugation in T2D patients and their first-degree relatives (42 Caucasians and 33 South Asians), and in 29 normoglycemic controls from non-T2D families. Glucose tolerance, insulin sensitivity index (ISI) and insulin disposition index (DI) were assessed by an extended, frequently sampled oral glucose tolerance test (OGTT), and fractional insulin synthesis rate (FSR) was measured by 13C-leucine enrichment in urinary C-peptide during the OGTT. Of the first-degree relatives, 40, 16 and 19 had NGT, prediabetes and T2D, respectively. NGT family members had lower plasma HDL-cholesterol (HDLC) (1.34±0.07 vs 1.58±0.06 mmol/L; p=0.015), HDL2-C (0.41±0.05 vs 0.57±0.05mmol/L; p=0.021) and HDL3-C (0.62±0.03 vs 0.72±0.02mmol/L; p=0.043) than controls. HDL2-C levels tended to decrease with increasing glucose intolerance state. In South Asians, buoyant LDL-C levels decreased with increasing glucose intolerance state (p=0.006). In South Asian families, HDL-C correlated with both ISI and DI (β 0.42; p=0.04 and β 0.53; p=0.01, respectively), whereas HDL2-C and HDL3-C levels correlated with DI (β 0.64; p=0.002 and β 0.57; p=0.005, respectively). HDL2-C and plasma triglyceride correlated with FSR (β 0.48; p=0.033 and β -0.50; p=0.029, respectively). Low HDL2-C and HDL3-C levels are present in NGT first-degree relatives of T2D patients, and HDL2-C tend to decrease further with increasing glucose intolerance. In South Asian families HDL2-C and HDL3-C levels linked predominantly to deteriorating beta cell function.

Effect of Dysferlin Deficiency on Atherosclerosis and Plasma Lipoprotein Composition Under Normal and Hyperlipidemic Conditions.

Dysferlinopathies are a group of muscle disorders caused by mutations to dysferlin, a transmembrane protein involved in membrane patching events following physical damage to skeletal myofibers. We documented dysferlin expression in vascular tissues including non-muscle endothelial cells, suggesting that blood vessels may have an endogenous repair system that helps promote vascular homeostasis. To test this hypothesis, we generated dysferlin-null mice lacking apolipoprotein E (ApoE), a common model of atherosclerosis, dyslipidemia and endothelial injury when stressed with a high fat, and cholesterol-rich diet. Despite high dysferlin expression in mouse and human atheromatous plaques, loss of dysferlin did not affect atherosclerotic burden as measured in the aortic root, arch, thoracic, and abdominal aortic regions. Interestingly, we observed that dysferlin-null mice exhibit lower plasma high-density lipoprotein cholesterol (HDL-C) levels than their WT controls at all measured stages of the disease process. Western blotting revealed abundant dysferlin expression in protein extracts from mouse livers, the main regulator of plasma lipoprotein levels. Despite abnormal lipoprotein levels, Dysf/ApoE double knockout mice responded to cholesterol absorption blockade with lower total cholesterol and blunted atherosclerosis. Our study suggests that dysferlin does not protect against atherosclerosis or participate in cholesterol absorption blockade but regulates basal plasma lipoprotein composition. Dysferlinopathic patients may be dyslipidemic without greater atherosclerotic burden while remaining responsive to cholesterol absorption blockade.

Membrane type 1 matrix metalloproteinase promotes LDL receptor shedding and accelerates the development of atherosclerosis

Plasma low-density lipoprotein (LDL) is primarily cleared by LDL receptor (LDLR). LDLR can be proteolytically cleaved to release its soluble ectodomain (sLDLR) into extracellular milieu. However, the proteinase responsible for LDLR cleavage is unknown. Here we report that membrane type 1-matrix metalloproteinase (MT1-MMP) co-immunoprecipitates and co-localizes with LDLR and promotes LDLR cleavage. Plasma sLDLR and cholesterol levels are reduced while hepatic LDLR is increased in mice lacking hepatic MT1-MMP. Opposite effects are observed when MT1-MMP is overexpressed. MT1-MMP overexpression significantly increases atherosclerotic lesions, while MT1-MMP knockdown significantly reduces cholesteryl ester accumulation in the aortas of apolipoprotein E (apoE) knockout mice. Furthermore, sLDLR is associated with apoB and apoE-containing lipoproteins in mouse and human plasma. Plasma levels of sLDLR are significantly increased in subjects with high plasma LDL cholesterol levels. Thus, we demonstrate that MT1-MMP promotes ectodomain shedding of hepatic LDLR, thereby regulating plasma cholesterol levels and the development of atherosclerosis.

The Yin and Yang of High-density Lipoprotein and Atherosclerotic Cardiovascular Disease: Focusing on Functionality and Cholesterol Efflux to Reframe the HDL Hypothesis.

The inverse relationship between low plasma high-density lipoprotein cholesterol (HDL-C) concentrations and increased risk of Atherosclerotic Cardiovascular Disease (ASCVD) is well-known. However, plasma HDL-C concentrations are highly variable in subjects with ASCVD. In clinical outcome trials, pharmacotherapies that increase HDL-C concentrations are not associated with a reduction in ASCVD events. A causal relationship between HDL-C and ASCVD has also been questioned by Mendelian randomization studies and genome-wide association studies of genetic variants associated with plasma HDL-C concentrations. The U-shaped association between plasma HDL-C concentrations and mortality observed in several epidemiological studies implicates both low and very high plasma HDL-C concentrations in the etiology of ASCVD and non- ASCVD mortality. These data do not collectively support a causal association between HDL-C and ASCVD risk. Therefore, the hypothesis concerning the association between HDL and ASCVD has shifted from focus on plasma concentrations to the concept of functionality, in particular cellular cholesterol efflux and HDL holoparticle transport. In this review, we focus on these new concepts and provide a new framework for understanding and testing the role of HDL in ASCVD.

Fecal Microbiota Transplant from Human to Mice Gives Insights into the Role of the Gut Microbiota in Non-Alcoholic Fatty Liver Disease (NAFLD).

Non-alcoholic fatty liver diseases (NAFLD) are associated with changes in the composition and metabolic activities of the gut microbiota. However, the causal role played by the gut microbiota in individual susceptibility to NAFLD and particularly at its early stage is still unclear. In this context, we transplanted the microbiota from a patient with fatty liver (NAFL) and from a healthy individual to two groups of mice. We first showed that the microbiota composition in recipient mice resembled the microbiota composition of their respective human donor. Following administration of a high-fructose, high-fat diet, mice that received the human NAFL microbiota (NAFLR) gained more weight and had a higher liver triglycerides level and higher plasma LDL cholesterol than mice that received the human healthy microbiota (HR). Metabolomic analyses revealed that it was associated with lower and higher plasma levels of glycine and 3-Indolepropionic acid in NAFLR mice, respectively. Moreover, several bacterial genera and OTUs were identified as differently represented in the NAFLR and HR microbiota and therefore potentially responsible for the different phenotypes observed. Altogether, our results confirm that the gut bacteria play a role in obesity and steatosis development and that targeting the gut microbiota may be a preventive or therapeutic strategy in NAFLD management.

Atherogenic index of plasma: A novel biomarker and lipid indices in young myocardial infarction patients

Background: Cardiovascular diseases (CVDs) have become the leading cause of death among Indian population. It has been directly linked to hypercholesterolemia, particularly elevated plasma low-density lipoprotein-cholesterol (LDL-C) levels and low plasma high-density lipoprotein-cholesterol (HDL-C) levels. The lipid tetrad index (LTI) and lipid pentad index (LPI) have been recently described as a new form of assessment of lipid profiles. Hence, the present study was undertaken to evaluate the role of atherogenic index of plasma (AIP) and other lipid indices such as LTI and LPI in young myocardial infarction (MI) patients from North India.Methods: The present cross-sectional study was conducted in the Department of Biochemistry and Cardiology at GB Pant Institute of Postgraduate Medical Education and Research, New Delhi. A total of 240 individuals were included in the study in which 135 were patients of ST-elevation MI of the age 15–45 years, along with 105 age-matched controls during the period of July 2019 till December 2019. LTI was calculated as TC*TG*Lp(a)/HDL and LPI as TC*TG*Lp(a)*ApoB/ApoA1. AIP is calculated according to the formula: log (TG/HDL-C). Results: The lipid parameters including total cholesterol, triglyceride, LDL-C, and non-HDL-C were significantly increased in the acute MI cases in comparison to controls. HDL-C was significantly decreased in the cases. Lipoprotein (a), ApoB levels, and ApoB/ApoA1 were also significantly increased in the cases. On the other hand, ApoA1 levels were significantly decreased in the patients. LTI and LPI were significantly increased in the acute MI cases as compared to controls. On correlating lipid parameters with LTI and LPI, a significant positive correlation was observed with all lipid parameters – total cholesterol, triglyceride, LDL-C, Lp(a), and ApoB/ApoA1 except HDL-C which showed a negative correlation with LTI and a nonsignificantly negative correlation with LPI. HDL-C shows a significantly negative correlation with AIP in both cases and controls. Conclusions: This present study has evaluated Role of AIP along with lipid indices such as LTI & LPI which helps in early identification of individuals with higher risk of premature CAD. AIP can be used as a better biomarker than other lipid indices in young MI patients, especially those associated with cardiovascular risk. At present, no Lp(a)-lowering drugs have been approved, hence early identification and intervention to modify risk factor may be helpful in prevention of development of MI in these patients with the help of LTI and LPI levels.

Plasma lipids, tumor parameters and survival in HCC patients with HBV and HCV.

Introduction and aims:Hepatocellular carcinoma (HCC) is a consequence of chronic liver disease, particularly from hepatitis B or C and increasingly from obesity and metabolic syndrome. Since lipids are an important component of cell membranes and are involved in cell signaling and tumor cell growth, we wished to evaluate the relationship between HCC patient plasma lipids and maximum tumor diameter and other indices of HCC human biology.Methods:We examined prospectively-collected data from a multi-institutional collaborative Turkish HCC working group, from predominantly HBV-based patients, for plasma lipid profiles, consisting of triglycerides, total cholesterol, LDL-cholesterol (LDL) and HDL-cholesterol (HDL) and compared these with the associated patient maximum tumor diameter (MTD), portal vein thrombosis, alpha-fetoprotein (AFP) and also with patient survival.Results:We found that both low HDL (p=0.0002) and high LDL (p=0.003) levels were significantly associated with increased MTD, as well as in a final multiple linear regression model on MTD. The combination of low HDL combined with high HDL levels were significant in a regression model on MTD, PVT and an HCC Aggressiveness Index (Odds Ratio 12.91 compared to an Odds Ratio of 1 for the reference). Furthermore, in a Cox regression model on death, the HDL plus LDL combination had a significantly higher Hazard Ratio than the reference category.Conclusions:Low plasma HDL, high plasma LDL and especially the combination, were significantly related to more aggressive HCC phenotype and the combination was significantly related to a higher Hazard Ratio for death.

Distinct phenotypic characteristics of normal-weight adults at risk of developing cardiovascular and metabolic diseases

The normal-weight BMI range (18.5-24.9 kg/m2) includes adults with body shape and cardiometabolic disease risk features of excess adiposity, although a distinct phenotype developed on a large and diverse sample is lacking. To identify demographic, behavioral, body composition, and health-risk biomarker characteristics of people in the normal-weight BMI range who are at increased risk of developing cardiovascular and metabolic diseases based on body shape. Six nationally representative waist circumference index (WCI, weight/height0.5) prediction formulas, with BMI and age as covariates, were developed using data from 17,359 non-Hispanic (NH) white, NH black, and Mexican-American NHANES 1999-2006 participants. These equations were then used to predict WCI in 5594 NHANES participants whose BMI was within the normal weight range. Men and women in each race/Hispanic-origin group were then separated into high, medium, and low tertiles based on the difference (residual) between measured and predicted WCI. Characteristics were compared across tertiles; P values for significance were adjusted for multiple comparisons. Men and women in the high WCI residual tertile, relative to their BMI and age-equivalent counterparts in the low tertile, had significantly lower activity levels; higher percent trunk and total body fat (e.g. NH white men, X±SE, 25.3±0.2% compared with 20.4±0.2%); lower percent appendicular lean mass (skeletal muscle) and bone mineral content; and higher plasma insulin and triglycerides, higher homeostatic model assessment of insulin resistance (e.g. NH white men, 1.45±0.07 compared with 1.08±0.06), and lower plasma HDL cholesterol. Percent leg fat was also significantly higher in men but lower in women. Similar patterns of variable statistical significance were present within sex and race/ethnic groups. Cardiometabolic disease risk related to body shape in people who are normal weight according to BMI is characterized by a distinct phenotype that includes potentially modifiable behavioral health risk factors.

Low high-density lipoprotein and increased risk of several cancers: 2 population-based cohort studies including 116,728 individuals

BackgroundIncreasing evidence suggests that high-density lipoprotein (HDL) may play a role in cancer development. We tested the hypothesis that low HDL levels are associated with increased risk of cancer.MethodsIndividuals from two population-based cohorts, the Copenhagen General Population Study (2003–2015, N = 107 341), and the Copenhagen City Heart Study (1991–1994, N = 9387) were followed prospectively until end of 2016 to assess low plasma HDL cholesterol and apolipoprotein A1 as risk factors for cancer using Cox proportional hazard regression.ResultsDuring up to 25 years follow-up, we observed 8748 cancers in the Copenhagen General Population Study and 2164 in the Copenhagen City Heart Study. In the Copenhagen General Population Study and compared to individuals with HDL cholesterol ≥ 2.0 mmol/L (≥ 77 mg/dL), multivariable adjusted hazard ratios (HRs) for any cancer were 1.13 (95% confidence interval 1.04–1.22) for individuals with HDL cholesterol of 1.5–1.99 mmol/L (58–77 mg/dL), 1.18 (1.08–1.30) for HDL cholesterol of 1.0–1.49 mmol/L (39–58 mg/dL), and 1.29 (1.12–1.48) for individuals with HDL cholesterol < 1.0 mmol/L (< 39 mg/dL). Correspondingly, compared to individuals with apolipoprotein A1 ≥ 190 mg/dL, HRs for any cancer were 1.06 (0.96–1.17) for individuals with apolipoprotein A1 of 160–189 mg/dL, 1.18 (1.07–1.30) for apolipoprotein A1 of 130–159 mg/dL, and 1.28 (1.13–1.46) for individuals with apolipoprotein A1 < 130 mg/dL. Among 27 cancer types, low HDL cholesterol and/or apolipoprotein A1 were associated with increased risk of multiple myeloma, myeloproliferative neoplasm, non-Hodgkin lymphoma, breast cancer, lung cancer, and nervous system cancer. Results were overall similar in women and men separately, and in the Copenhagen City Heart Study.ConclusionsLow HDL levels were associated with increased risk of several cancers. Increased risk was most pronounced for hematological and nervous system cancer, and to a minor extent for breast and respiratory cancer.