SORBS2 as a molecular target for atherosclerosis in patients with familial hypercholesterolemia.

BACKGROUND: Familial hypercholesterolemia (FH) is a metabolic disease in which patients are prone to develop premature atherosclerosis (AS). Sorbin and SH3 Domain Containing 2 (SORBS2) is known to play a role in coronary heart disease (CHD). However, the mechanism underlying SORBS2 involvement in the development of hypercholesterolemia remains unknown. Here, we investigated the effects of SORBS2 on inflammation and foam cell formation and its underlying mechanisms. METHODS: Using Bioinformatics analysis, we established that SORBS2 is upregulated in patients with FH. Circulating concentrations of SORBS2 were measured using ELISA kit (n = 30). The association between circulating SORBS2 levels and inflammatory factors or lipid indexes were conducted using Spearman correlation analysis. We further conducted in vitro experiments that the expression of SORBS2 were analyzed, and SORBS2 siRNA were transfected into oxidized LDL (OxLDL)-induced macrophages, followed by western blot and immunofluorescence. RESULTS: Circulating SORBS2 levels were positively associated with inflammatory factors and lipid indexes. We also observed that high in vitro expression of SORBS2 in OxLDL-induced macrophages. After SORBS2 silencing, Nod like receptor family pyrin domain-containing 3 protein(NLRP3)-Caspase1 activation and NF-κB activation were attenuated, and secretion of pro-inflammatory cytokines (IL-1ß and IL-18) was decreased. Moreover, SORBS2 silencing blocked reactive oxygen species (ROS) production and lipid accumulation, and promoted cholesterol efflux through ABCG1-PPARγ pathway. CONCLUSIONS: SORBS2 regulates lipid-induced inflammation and foam cell formation, and is a potential therapeutic target for hypercholesterolemia.

Lipoprotein (a)-mediated vascular calcification: population-based and in vitro studies.

BACKGROUND: Lipoprotein (a) [Lp(a)] is a causal risk factor for cardiovascular diseases, while its role in vascular calcification has not been well-established. Here, we investigated an association of Lp(a) with vascular calcification using population-based and in vitro study designs. METHODS: A total of 2806 patients who received coronary computed tomography were enrolled to assess the correlation of Lp(a) with the severity of coronary artery calcification (CAC). Human aortic smooth muscle cells (HASMCs) were used to explore mechanisms of Lp(a)-induced vascular calcification. RESULTS: In the population study, Lp(a) was independently correlated with the presence and severity of CAC (all p < 0.05). In vitro study showed that cell calcific depositions and alkaline phosphatase (ALP) activity were increased and the expression of pro-calcific proteins, including bone morphogenetic protein-2 (BMP2) and osteopontin (OPN), were up-regulated by Lp(a) stimulation. Interestingly, Lp(a) activated Notch1 signaling, resulting in cell calcification, which was inhibited by the Notch1 signaling inhibitor, DAPT. Lp(a)-induced Notch1 activation up-regulated BMP2-Smad1/5/9 pathway. In contrast, Noggin, an inhibitor of BMP2-Smad1/5/9 pathway, significantly blocked Lp(a)-induced HASMC calcification. Notch1 activation also induced translocation of nuclear factor-κB (NF-κB) accompanied by OPN overexpression and elevated inflammatory cytokines production, while NF-κB silencing alleviated Lp(a)-induced vascular calcification. CONCLUSIONS: Elevated Lp(a) concentrations are independently associated with the presence and severity of CAC and the impact of Lp(a) on vascular calcification is involved in the activation of Notch1-NF-κB and Notch1-BMP2-Smad1/5/9 pathways, thus implicating Lp(a) as a potential novel therapeutic target for vascular calcification.

Liver fibrosis scores and coronary atherosclerosis: novel findings in patients with stable coronary artery disease.

BACKGROUND: Although non-invasive liver fibrosis scores (LFSs) have already been considered as effective tools for estimating cardiovascular risk, their roles in predicting disease severity and cardiovascular event (CVEs) in patients with stable coronary artery disease (CAD) are not comprehensively evaluated. The aim of the present study was to investigate whether non-alcoholic fatty liver disease fibrosis score (NAFLD-FS) and fibrosis-4 (FIB-4) are associated with CVEs in a large cohort with long-term follow-up. METHODS: A cohort of 5143 patients with angiography-proven stable CAD were consecutively enrolled and followed up for CVEs. The degree of coronary severity was assessed using the number of diseased vessels, Gensini, Syntax, and Jeopardy scores. The predictive values of NAFLD-FS and FIB-4 scores to coronary severity, coronary calcification (CAC), and CVEs were assessed, respectively. RESULTS: During a median follow-up of 7 years, 435 CVEs were recorded. Both NAFLD-FS and FIB-4 were predictors for the presence of CAC. The degree of coronary stenosis was significantly higher in high NAFLD-FS categories while FIB-4 was only positively associated with the number of diseased vessels and Gensini score. In Kaplan-Meier analysis, the patients with intermediate and high NAFLD-FS and FIB-4 had higher risk of CVEs and cardiovascular mortality. In multivariate Cox regression analysis, NAFLD-FS and FIB-4 were independently associated with CVEs [hazard ratio (95% confidence interval): 1.150 (1.063-1.244), p < 0.001 and 1.128 (1.026-1.240), p = 0.012]. CONCLUSION: The current data first indicated that both NAFLD-FS and FIB-4 scores were not only significantly related to coronary severity but also associated with CAC and CVEs. CLINICAL TRIALS REGISTRATION: None.

Association of small dense LDL-cholesterol with disease severity, hypertension status and clinical outcome in patients with coronary artery disease.

OBJECTIVE: Previous studies have demonstrated that small dense LDL-cholesterol (sdLDL-C) is related to the pathogenesis of coronary artery disease (CAD). However, its prognostic role in hypertensive patients with CAD has been undetermined. The aim of the study was to investigate the association between sdLDL-C with disease severity, hypertensive status and clinical outcome in patients with CAD. METHODS: A total of 4594 patients with angiography-proven CAD were consecutively enrolled and categorized into subgroups according to blood pressure status. Serum sdLDL-C levels were measured by direct quantitative measurement using automated chemistry analyzers. The severity of coronary artery lesions were determined by Gensini score, Syntax score and the number of lesion vessels. The associations of sdLDL-C with disease severity, hypertensive status and cardiovascular events (CVEs) were evaluated. RESULTS: Patients with hypertension had higher sdLDL-C levels than ones without (P = 0.010). In hypertensive patients, sdLDL-C was positively associated with the severity of CAD (P < 0.05). In addition, hypertensive patients with poorly controlled hypertension had higher sdLDL-C levels than those with well controlled (P < 0.05). Moreover, 149 CVEs occurred in patients with poorly controlled hypertension and Cox regression analysis indicated that elevated sdLDL-C levels were independently associated with CVEs in hypertensive patients with poorly controlled hypertension (adjusted hazard ratio: 1.673, 95% confidence interval: 1.105-2.535, P = 0.015). CONCLUSION: The current data, for the first time, showed that serum sdLDL-C levels were correlated with hypertension control, disease severity and worse outcomes in hypertensive patients with CAD, suggesting that paying more attention on sdLDL-C in these patients were warranted.

Heart-type fatty acid binding protein predicts cardiovascular events in patients with stable coronary artery disease: a prospective cohort study.

BACKGROUND: Heart-type fatty acid binding protein (H-FABP) has been reported to be a prognostic predictor for cardiovascular outcome in acute coronary syndrome (ACS). However, its prognostic utility in patients with stable coronary artery disease (CAD) has not been well established. The aim of this study was to assess the association between H-FABP with the severity of coronary disease and cardiovascular events (CVEs) in patients with stable CAD. METHODS: A total of 4,370 angiography-proven CAD patients were consecutively enrolled. The severity of CAD was assessed by Gensini Score (GS) and the numbers of diseased vessels. The CVEs included cardiovascular death, myocardial infarction, stroke and coronary revascularization. Cox regression analysis with adjusted hazard ratios (HRs) and Kaplan-Meier analysis were used to evaluate the relation of H-FABP to CVEs in this cohort. RESULTS: During a median follow-up of 51 months, 353 CVEs occurred. Overall, patients in the highest levels of H-FABP group had increased rate of multi-vessel stenosis and higher GS compared with those in the lowest group (P<0.05, respectively). Moreover, H-FABP levels were significantly higher in patients with events compared to those without (P<0.001). In Cox regression analysis, elevated H-FABP levels were found to be independently associated with a high risk of CVEs [adjusted HRs: 1.453; 95% confidence intervals (CIs): 1.040-2.029, P=0.028], especially with cardiovascular death (adjusted HRs: 2.865; 95% CI: 1.315-6.243, P=0.008). CONCLUSIONS: Our results demonstrated that H-FABP was also a useful predictor for CVEs in patients with stable CAD, which needed to be verified by further studies.

Prognostic utility of lipoprotein(a) combined with fibrinogen in patients with stable coronary artery disease: a prospective, large cohort study.

BACKGROUND: Elevated lipoprotein(a) [Lp(a)] and fibrinogen (Fib) are both associated with coronary artery disease (CAD). The atherogenicity of Lp(a) can be partly due to the potentially antifibrinolytic categories. We hypothesize that patients with higher Lp(a) and Fib may have worse outcomes. METHODS: In this prospective study, we consecutively enrolled 8,417 Chinese patients with stable CAD from March 2011 to March 2017. All subjects were divided into 9 groups according to Lp(a) (Lp(a)-Low, Lp(a)-Medium, Lp(a)-High) and Fib levels (Fib-Low, Fib-Medium, Fib-High) and followed up for CVEs, including nonfatal acute myocardial infarction, stroke, and cardiovascular mortality. Kaplan-Meier, Cox regression and C-statistic analyses were performed. RESULTS: During a median of 37.1 months' follow-up, 395 (4.7%) CVEs occurred. The occurrence of CVEs increased by Lp(a) (3.5 vs. 5.3 vs. 5.6%, p = 0.001) and Fib (4.0 vs. 4.4 vs. 6.1%, p < 0.001) categories. When further classified into 9 groups by Lp(a) and Fib levels, the CVEs were highest in the 9th (Lp(a)-High and Fib-High) compared with the 1st (Lp(a)-Low and Fib-Low) group (7.2 vs. 3.3%, p < 0.001). The highest risk of subsequent CVEs was found in the 9th group (HRadjusted 2.656, 95% CI 1.628-4.333, p < 0.001), which was more significant than Lp(a)-High (HRadjusted 1.786, 95% CI 1.315-2.426, p < 0.001) or Fib-High (HRadjusted 1.558, 95% CI 1.162-2.089, p = 0.003) group. Moreover, adding the combined Lp(a) and Fib increased the C-statistic by 0.013. CONCLUSION: Combining Fib and Lp(a) enhance the prognostic value for incident CVEs beyond Lp(a) or Fib alone.

Long-term prognostic utility of low-density lipoprotein (LDL) triglyceride in real-world patients with coronary artery disease and diabetes or prediabetes.

BACKGROUND: Recent guidelines highlighted the association between atherosclerosis and triglyceride-enriched lipoproteins in patients with impaired glucose metabolism. However, evidence from prospective studies for long-term prognostic utility of low-density lipoprotein triglyceride (LDL-TG) in real-world patients with prediabetes (Pre-DM) or diabetes mellitus (DM) and coronary artery disease (CAD) is currently not available. The aim of the present study was to evaluate the impact of LDL-TG on major adverse cardiovascular events (MACEs) in patients with stable CAD under different glucose metabolism status. METHODS: A total of 4381 patients with CAD were consecutively enrolled and plasma LDL-TG level was measured by an automated homogeneous assay. They were categorized according to both status of glucose metabolism [DM, Pre-DM, normal glycaemia regulation (NGR)] and tertiles of LDL-TG. All subjects were followed up for the occurrence of MACEs. RESULTS: During a median of 5.1 (interquartile range 3.9 to 5.9) years' follow-up, 507 (11.6%) MACEs occurred. Cubic spline models showed a significant association between LDL-TG and MACEs in DM and Pre-DM but not in NGR. When the combined effect of elevated LDL-TG and glucose disorders was considered for risk stratification, the medium tertile of LDL-TG plus DM, and the highest tertile of LDL-TG plus Pre-DM or plus DM subgroups were associated with significantly higher risk of MACEs after adjustment of confounders including triglyceride [hazard ratios (95% confidence intervals): 1.843 (1.149-2.955), 1.828 (1.165-2.867), 2.212 (1.396-3.507), all p < 0.05]. Moreover, adding LDL-TG into the original model increased the C-statistic from 0.687 to 0.704 (∆C-statistic = 0.016, p = 0.028) and from 0.734 to 0.749 (∆C-statistic = 0.014, p = 0.002) in Pre-DM and DM, respectively. CONCLUSIONS: In this longitudinal cohort study on real-world practice, higher LDL-TG was associated with worse outcomes among Pre-DM and DM patients with stable CAD.

The longitudinal association of remnant cholesterol with cardiovascular outcomes in patients with diabetes and pre-diabetes.

BACKGROUND: The atherogenicity of remnant cholesterol (RC) has been underlined by recent guidelines, which was linked to coronary artery disease (CAD), especially for patients with diabetes mellitus (DM). This study aimed to examine the prognostic value of plasma RC in the patients with CAD under different glucose metabolism status. METHODS: Fasting plasma RC were directly calculated or measured in 4331 patients with CAD. Patients were followed for the occurrence of major adverse cardiovascular events (MACEs) and categorized according to both glucose metabolism status [DM, pre-DM, normoglycemia (NG)] and RC levels. Cox proportional hazards model was used to calculate hazard ratios (HRs) with 95% confidence intervals. RESULTS: During a mean follow-up of 5.1 years, 541 (12.5%) MACEs occurred. The risk for MACEs was significantly higher in patients with elevated RC levels after adjustment for potential confounders. No significant difference in MACEs was observed between pre-DM and NG groups (p > 0.05). When stratified by combined status of glucose metabolism and RC, highest levels of calculated and measured RC were significant and independent predictors of developing MACEs in pre-DM (HR: 1.64 and 1.98; both p < 0.05) and DM (HR: 1.62 and 2.05; both p < 0.05). High RC levels were also positively associated with MACEs in patients with uncontrolled DM. . CONCLUSIONS: In this large-scale and long-term follow-up cohort study, data firstly demonstrated that higher RC levels were significantly associated with the worse prognosis in DM and pre-DM patients with CAD, suggesting that RC may be a target for patients with impaired glucose metabolism.

Beneficial impact of epigallocatechingallate on LDL-C through PCSK9/LDLR pathway by blocking HNF1α and activating FoxO3a.

BACKGROUND: Green tea drinking has been proven to lower lipid and exert cardiovascular protection, while the potential mechanism has not been fully determined. This study was to investigate whether the beneficial impact of epigallocatechingallate (EGCG), a type of catechin in green tea on lipids is associated with proprotein convertase subtilisin/kexin type 9 (PCSK9) pathways. METHODS: We studied the effects and underlying molecular mechanism of EGCG or green tea on regulating cholesterol from human, animal and in vitro. RESULTS: In the age- and gender-matched case control observation, we found that individuals with frequent tea consumption (n = 224) had the lower plasma PCSK9 and low density lipoprotein cholesterol (LDL-C) levels compared with ones without tea consumption (n = 224, p < 0.05). In the high fat diet (HFD) fed rats, EGCG administration significantly lowered circulating PCSK9 concentration and liver PCSK9 expression, along with up-regulated LDL receptor (LDLR) expression but decreased level of LDL-C. In hepatic cell study, similar results were obtained regarding the impact of EGCG on LDLR and PCSK9 expression. The assay transposase-accessible chromatic with high-throughput sequencing (ATAC-seq) and subsequent results suggested that two transcription factors, hepatocyte nuclear factor-1α (HNF-1α) and forkhead box class O (FoxO) 3a involved in inhibitory action of EGCG on PCSK9 expression. CONCLUSIONS: The present study demonstrates that EGCG suppresses PCSK9 production by promoting nuclear FoxO3a, and reducing nuclear HNF1α, resulting in up-regulated LDLR expression and LDL uptake in hepatocytes. Thereby inhibiting liver and circulating PCSK9 levels, and ultimately lowering LDL-C levels.

Association of small dense low-density lipoprotein with cardiovascular outcome in patients with coronary artery disease and diabetes: a prospective, observational cohort study.

BACKGROUND: Elevation in small dense low-density lipoprotein (sdLDL) is common in patients with diabetes mellitus (DM), which has already been reported to be associated with incidence of coronary artery disease (CAD). The aim of the present study was to investigate the prognostic value of plasma sdLDL level in patients with stable CAD and DM. METHODS: A total of 4148 consecutive patients with stable CAD were prospectively enrolled into the study and followed up for major cardiovascular events (MACEs) up to 8.5 years. Plasma sdLDL level was measured in each patient by a direct method using automated chemistry analyzer. The patients were subsequently divided into four groups by the quartiles of sdLDL and the association of sdLDL level with MACEs in different status of glucose metabolism [DM, Pre-DM, normal glycaemia regulation (NGR)] was evaluated. RESULTS: A total of 464 MACEs were documented. Both Kaplan-Meier analysis and Cox regression analysis indicated that the patients in quartile 4 but not quartile 2 or 3 of sdLDL level had significantly higher rate of MACEs than that in lowest quartile. When the prognostic value of high sdLDL was assessed in different glucose metabolism status, the results showed that the high sdLDL plus DM was associated with worse outcome after adjustment of confounding risk factors (hazard ratio: 1.83, 95% confident interval: 1.24-2.70, p < 0.05). However, no significant association was observed for high sdLDL plus Pre-DM or NGR. CONCLUSIONS: The present study firstly indicated that elevated levels of plasma sdLDL were associated with increased risk of MACEs among DM patients with proven CAD, suggesting that sdLDL may be useful for CAD risk stratification in DM.

Prognostic utility of heart-type fatty acid-binding protein in patients with stable coronary artery disease and impaired glucose metabolism: a cohort study.

BACKGROUND: Heart-type fatty acid-binding protein (H-FABP) is a novel marker of myocardial injury and has been reported to be associated with cardiovascular diseases (CVD) including patients with diabetes mellitus (DM). Unfortunately, its prognostic value in patients with CVD and impaired glucose metabolism (IGM) is unclear. The objective of this study was to investigate the prognostic value of H-FABP in CVD patients with IGM. METHODS: A total of 4594 patients with angiography-proven coronary artery disease (CAD) were enrolled and divided into subgroup according to glucose metabolism status (normal glucose regulation [NGR], pre-DM, and DM). Baseline levels of H-FABP were measured using latex immunoturbidimetric method. The cardiovascular events (CVE) were defined as cardiovascular death, myocardial infarction, stroke and coronary revascularization. Cox regression and Kaplan-Meier analysis were used to evaluate the relations of H-FABP and glucose metabolism status to CVEs. RESULTS: During the follow-up period with up to 7.1 years, 380 CVEs occurred. Patients with CVE had higher levels of H-FABP compared to those without CVE (p < 0.001). Interestingly, H-FABP levels were also elevated in DM and pre-DM groups compared with NGR group (p < 0.001), when combined glucose metabolism status with H-FABP stratification, patients in the highest tertile of H-FABP appeared to have higher risk of CVEs with pre-DM (adjusted hazard ratio [HR]: 1.855, 95% confidential intervals [CIs] 1.076-3.214; p = 0.033) and DM (adjusted HR: 2.560, 95% CIs 1.409-4.650; p = 0.002). The Kaplan-Meier curve indicated that DM patients with the highest H-FABP levels were associated with the greatest risk of CVEs (p < 0.05). CONCLUSIONS: Our data firstly showed that elevated H-FABP levels were associated with worse outcomes in CAD patients with pre-DM and DM, which provided the novel information that H-FABP might be a prognostic marker for clinical outcomes among patients with CAD and IGM.

Genetic basis of index patients with familial hypercholesterolemia in Chinese population: mutation spectrum and genotype-phenotype correlation.

BACKGROUND: Although there have been many reports in the genetics of familial hypercholesterolemia (FH) worldwide, studies in regard of Chinese population are lacking. In this multi-center study, we aim to characterize the genetic spectrum of FH in Chinese population, and examine the genotype-phenotype correlations in detail. METHODS: A total of 285 unrelated index cases from China with clinical FH were consecutively recruited. Next-generation sequencing and bioinformatics tools were used for mutation detection of LDLR, APOB and PCSK9 genes and genetic analysis. RESULTS: Overall, the detection rate is 51.9% (148/285) in the unrelated index cases with a total of 119 risk variants identified including 84 in the LDLR gene, 31 in APOB and 4 in PCSK9 gene. Twenty-eight variants were found in more than one individual and LDLR c.1448G > A (p. W483X) was most frequent one detected in 9 patients. Besides, we found 8 (7 LDLR and 1 APOB) novel variants referred as "pathogenic (or likely pathogenic) variants" according to in silico analysis. In the phenotype analysis, patients with LDLR null mutation had significantly higher LDL cholesterol level than LDLR defective and APOB/PCSK9 mutation carriers and those with no mutations (p < 0.001). Furthermore, 13 double heterozygotes, 16 compound heterozygotes and 5 true LDLR homozygotes were identified and the true LDLR homozygotes had the most severe phenotypes. CONCLUSIONS: The present study confirmed the heterogeneity of FH genetics in the largest Chinese cohort, which could replenish the knowledge of mutation spectrum and contribute to early screening and disease management.

Relationship between Plasma Proprotein Convertase Subtilisin/Kexin Type 9 and Estimated Glomerular Filtration Rate in the General Chinese Population.

BACKGROUND: Elevated levels of proprotein convertase subtilisin/kexin type 9 (PCSK9) have been reported to be related to dyslipidemia, including patients with kidney dysfunction. However, its association with estimated glomerular filtration rate (eGFR) in individuals with normal serum creatinine (SCr) has not been determined. METHODS: A total of 2,089 subjects with normal SCr and without lipid-lowering treatment were consecutively enrolled in this study. Plasma PCSK9 levels were measured by ELISA kit and eGFR was evaluated by the Chronic Kidney Disease Epidemiology Collaboration equation. Subjects were divided into a normal eGFR group (n = 1,205, ≥90 mL/min/1.73 m2) and a decreased eGFR group (n = 884, < 90 mL/min/1.73 m2). Baseline characteristics and laboratory findings were compared between the two groups. Spearman's correlation and linear regression were performed to determine the association between PCSK9 and eGFR. RESULTS: No significant difference in PCSK9 levels was found between the normal eGFR group and the decreased eGFR group (236.84 ± 67.87 vs. 239.98 ± 68.72 ng/mL, p = 0.303). In Spearman's correlation and multivariable linear regression analysis, no association of PCSK9 levels with eGFR was detected in the total cohort (r = -0.039, p = 0.079; adjusted ß = -0.013, p = 0.630). This result remained the same in the subgroups of normal eGFR (r = -0.038, p = 0.190; adjusted ß = -0.031, p = 0.367) and decreased eGFR (r = -0.054, p = 0.109; adjusted ß = -0.034, p = 0.319). CONCLUSION: In this single-center study with moderate sample size, the data showed no relationship of PCSK9 levels with normal or decreased eGFR in untreated patients with normal SCr, suggesting that further studies may be needed to understand the relationship between PCSK9 and lipid disorder in different stage of kidney dysfunction.

Familial hypercholesterolemia in very young myocardial infarction.

Familial hypercholesterolemia (FH) is one of the most common causes of premature myocardial infarction (MI). However, The patterns of FH remained unrecognized in clinical care, especially in very young patients (VYPs, ≤35 years) with MI. The present study enrolled a total of 1,093 VYPs (≤35 years) presenting a first MI. Clinical diagnosis of FH was made using Dutch Lipid Clinic Network criteria. Coronary severity was assessed by Gensini score (GS). Patients were followed for a median of 40-months with cardiac death, stroke, MI, post-discharge revascularization or unstable angina as primary endpoints. The detected rates of definite/probable FH were 6.5%. The prevalence reached up to 10.3% in patients ≤25 years. The FH had similar levels of comorbidities but was younger, more likely to be very high risk (VHR) and had higher GS (p < 0.05) than unlikely FH. Notably, the FH on prior lipid-lowering medication presented a lower GS compared to those untreated. Differences in event rates were similar in FH as unlikely FH (11.8% vs. 8.1%, adjusted hazard ratio 1.35 [0.64-2.86], p = 0.434) but patients on treatment improved outcome (6.5% vs. 10.5%, adjusted hazard ratio 0.35[0.13-0.95], p = 0.039). The early identification and treatment might be critical to reduce cardiovascular risk in VYPs with MI.

Liraglutide downregulates hepatic LDL receptor and PCSK9 expression in HepG2 cells and db/db mice through a HNF-1a dependent mechanism.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9), a major regulator of cholesterol homeostasis, is associated with glucose metabolism. Liraglutide, a glucagon-like peptide-1 receptor agonist, can increase insulin secretion in a glucose-dependent manner and lower blood glucose. We aimed to investigate the relationship between liraglutide and PCSK9. METHODS: At the cellular level, the expressions of PCSK9 and hepatocyte nuclear factor 1 alpha (HNF1α) protein in HepG2 cells stimulated by liraglutide was examined using Western blot. Seven-week old db/db mice and wild type (WT) mice were administered either liraglutide (200 µg/kg) or equivoluminal saline subcutaneously, twice daily for 7 weeks. Fasting glucose level, food intake and body weight were measured every week. After the 7-week treatment, the blood was collected for lipid and PCSK9 levels detection and the liver was removed from the mice for oil red O staining, immunohistochemical analysis, immunofluorescence test and Western bolt. RESULTS: Firstly, liraglutide suppressed both PCSK9 and HNF1α expression in HepG2 cells in a time and concentration dependent manner. Secondly, liraglutide induced weight loss in WT and db/db mice, decreased serum PCSK9, glucose and lipid levels and improved hepatic accumulation in db/db but not WT mice. Thirdly, liraglutide reduced both hepatic PCSK9 and low-density lipoprotein receptor (LDLR) expression with a decrease in HNF1α in db/db mice but not in WT mice. CONCLUSIONS: Liraglutide suppressed PCSK9 expression through HNF1α-dependent mechanism in HepG2 cells and db/db mice, and decreased LDLR possibly via PCSK9-independent pathways in db/db mice.

Association between lipoprotein (a) and proprotein convertase substilisin/kexin type 9 in patients with heterozygous familial hypercholesterolemia: A case-control study.

BACKGROUND: Recent data have suggested an important role of lipoprotein (a) [Lp(a)] and proprotein convertase substilisin/kexin type 9 (PCSK9) in the development of atherosclerotic cardiovascular disease (ASCVD) in both general population and family hypercholesterolemia (FH), while the relation of Lp(a) to PCSK9 has not been examined. OBJECTIVE: The aim of the present study was to investigate the association between plasma PCSK9 and Lp(a)in patients with heterozygous FH (HeFH). METHODS: Two hundred and fifty-five molecularly confirmed patients with HeFH were compared to 255 age- and gender-matched non-FH controls. Plasma PCSK9 and Lp(a) concentrations were measured using ELISA and immunoturbidimetric method respectively, and finally their association was assessed. RESULTS: Both plasma PCSK9 and Lp(a) levels were significantly higher in patients with HeFH compared to control group (p<0.001). Besides, the Lp(a) concentration and percentage of Lp(a)≥300mg/L were increased by PCSK9 tertiles in HeFH group (both p<0.05) while not in control group. In partial correlation analysis, Lp(a) was associated with PCSK9 (r=0.254, p<0.001) in HeFH group but not in control, which were further confirmed by multivariable linear regression analysis. Furthermore, significant associations between Lp(a) and PCSK9 were also found in subgroups of HeFH group irrespective of definite or probable FH, with and without coronary artery disease (CAD), and with statin or not. CONCLUSIONS: Plasma Lp(a) level was associated with PCSK9 in patients with HeFH alone, suggesting that much about the interaction of PCSK9 with Lp(a) in FH need further explorations.

Triglyceride to High-Density Lipoprotein Cholesterol Ratio and Cardiovascular Events in Diabetics With Coronary Artery Disease.

BACKGROUND: It has been demonstrated that an elevated ratio of triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C) is a risk factor of coronary artery disease (CAD) in patients with type 2 diabetes mellitus (T2DM) and is also found to be associated with cardiovascular events (CVEs) in the general population. However, its prognostic value in patients with T2DM along with CAD remains to be determined. MATERIALS AND METHODS: A total of 1,447 consecutive patients with T2DM with angiographic-proven stable CAD were enrolled in the present study and followed-up for an average of 20.3 months. The characteristics of all patients including fasting lipid profile were obtained at baseline and multivariate Cox proportional hazards models were constructed using log TG/HDL-C as a predictor variable. The relationships between CVEs and total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), non-HDL-C, TC/HDL-C, LDL-C/HDL-C and apolipoprotein B/ apolipoprotein AI (apoB/apoAI) were also explored. RESULTS: Compared with patients without CVEs, the ones who experienced CVEs had a higher TG/HDL-C ratio. Univariable regression revealed a significant association of log TG/HDL-C with CVEs (hazard ratio = 2.5, P = 0.015). After adjusting for multiple traditional risk factors of cardiovascular disease, the association was still found (hazard ratio = 2.47, P = 0.047). Moreover, results suggested that the ratios of non-HDL-C, TC/HDL-C, LDL-C/HDL-C and apoB/apoAI were not predictors for CVEs in T2DM. CONCLUSIONS: In our primary study, data suggested that elevated TG/HDL-C value might be a useful predictor for future CVEs in Chinese patients with T2DM with stable CAD. Further study is needed to confirm our findings.

Elevated resting heart rate is associated with the severity of coronary artery disease in non-treated patients who underwent coronary angiography: potential role of lipoprotein subfractions.

OBJECTIVE: To assess the association between resting heart rate (RHR) and lipoprotein subfractions to provide potential evidence for the relationship between RHR and severity of CAD. METHODS: A total of 1119 consecutive non-treated subjects scheduled for coronary angiography were enrolled. High-density lipoprotein (HDL) and low-density lipoprotein (LDL) separation were performed by Lipoprint System. The link of RHR with lipoprotein subfractions was assessed. RESULTS: Increased RHR was significantly associated with higher triglyceride, total cholesterol, non-HDL-cholesterol, and apolipoprotein B (all p < .01). Furthermore, data indicated that higher RHR was related to more severe CAD (all p < .05). In the following linear regression models, we observed that higher RHR (HRh bpm) was significantly associated with lower large HDL (ß = -0.073, p = .024) and higher small LDL subfraction (ß = 0.103, p = .005) after adjusting for potential confounders. CONCLUSIONS: Increased RHR was associated with more severe CAD, which may be partly due to the significant relation to atherogenic lipoprotein subfractions.

Serum fibrinogen and cardiovascular events in Chinese patients with type 2 diabetes and stable coronary artery disease: a prospective observational study.

OBJECTIVES: The aim of this study was to investigate the association of serum fibrinogen with cardiovascular events (CVE) in Chinese patients with type 2 diabetes mellitus (T2DM) and stable coronary artery disease (CAD). DESIGN: An observational study. SETTING: FuWai Hospital in Beijing, China. PARTICIPANTS: A cohort of 1466 patients with T2DM and angiographic-proven stable CAD was evaluated. OUTCOME MEASURES: Baseline serum fibrinogen levels were measured and trisected into 'low', 'middle' and 'high'. Their association with CVE was explored using Cox proportional hazard models. RESULTS: With 20.2 months (average) follow-up, 44 (3%) were lost to follow-up and 96 patients developed CVE. Compared with the patients without CVE, the ones who developed CVE had higher levels of fibrinogen. Univariable regression revealed a significant relation of fibrinogen to CVE (HR (HR) 1.25, 95% CI 1.06 to 1.47, p=0.010) per SD increase of fibrinogen at baseline. After adjusting for multiple established cardiovascular disease (CVD) risk factors, the association persisted (HR 1.30, 95% CI 1.02 to 1.66, p=0.037). Moreover, after adjusting for CVD risk factors, the HRs for middle-serum and high-serum fibrinogen concentration, using 'low' group as reference, were 1.23 (95% CI 0.69 to 2.20) and 2.20 (95% CI 1.11 to 3.36, p=0.049). CONCLUSIONS: We first indicated that elevated fibrinogen level was independently associated with increased CVE in Chinese patients with T2DMand stable CAD.

Significance of lipoprotein(a) levels in familial hypercholesterolemia and coronary artery disease.

BACKGROUND AND AIMS: Patients with familial hypercholesterolemia (FH) are often characterized by premature coronary artery disease (CAD) with heterogeneity at onset. The aim of the present study was to investigate the associations of lipoprotein (a) [Lp(a)] with the FH phenotype, genotype and roles of Lp(a) in determining CAD risk among patients with and without FH. METHODS: We enrolled 8050 patients undergoing coronary angiography, from our Lipid clinic. Clinical FH was diagnosed using the Dutch Lipid Clinic Network criteria. Mutational analysis (LDLR, APOB, PCSK9) in definite/probable FH was performed by target exome sequencing. RESULTS: Lp(a) levels were increased, with a clinical FH diagnosis (unlikely, possible, definite/probable FH) independent of the patients status, with Lp(a)-hyperlipoproteinemia [Lp(a)-HLP] (median 517.70 vs. 570.98 vs. 604.65 mg/L, p < 0.001) or without (median 89.20 vs. 99.20 vs. 133.67 mg/L, p < 0.001). Patients with Lp(a)-HLP had a higher prevalence of definite/probable FH than those without (6.1% vs. 2.4%, p < 0.05). However, no significant difference in Lp(a) was observed in patients with definite/probable FH phenotype carrying LDLR or LDLR-independent (APOB, PCSK9) or neither mutations (p > 0.05). Multivariate analysis showed that Lp(a) and FH phenotype were both significant determinants in predicting the early onset and severity of CAD. Subsequently, patients with Lp(a)-HLP in definite/probable FH increased significantly the CAD risk (all p < 0.05). CONCLUSIONS: Lp(a) levels were higher in patients with FH phenotype than in those without, but no difference were found in FH patients of different mutated backgrounds. Moreover, Lp(a) and FH played a synergistic role in predicting the early onset and severity of CAD.