Efficacy and safety of alirocumab in reducing lipids and cardiovascular events.

BACKGROUND: Alirocumab, a monoclonal antibody that inhibits proprotein convertase subtilisin-kexin type 9 (PCSK9), has been shown to reduce low-density lipoprotein (LDL) cholesterol levels in patients who are receiving statin therapy. Larger and longer-term studies are needed to establish safety and efficacy. METHODS: We conducted a randomized trial involving 2341 patients at high risk for cardiovascular events who had LDL cholesterol levels of 70 mg per deciliter (1.8 mmol per liter) or more and were receiving treatment with statins at the maximum tolerated dose (the highest dose associated with an acceptable side-effect profile), with or without other lipid-lowering therapy. Patients were randomly assigned in a 2:1 ratio to receive alirocumab (150 mg) or placebo as a 1-ml subcutaneous injection every 2 weeks for 78 weeks. The primary efficacy end point was the percentage change in calculated LDL cholesterol level from baseline to week 24. RESULTS: At week 24, the difference between the alirocumab and placebo groups in the mean percentage change from baseline in calculated LDL cholesterol level was -62 percentage points (P<0.001); the treatment effect remained consistent over a period of 78 weeks. The alirocumab group, as compared with the placebo group, had higher rates of injection-site reactions (5.9% vs. 4.2%), myalgia (5.4% vs. 2.9%), neurocognitive events (1.2% vs. 0.5%), and ophthalmologic events (2.9% vs. 1.9%). In a post hoc analysis, the rate of major adverse cardiovascular events (death from coronary heart disease, nonfatal myocardial infarction, fatal or nonfatal ischemic stroke, or unstable angina requiring hospitalization) was lower with alirocumab than with placebo (1.7% vs. 3.3%; hazard ratio, 0.52; 95% confidence interval, 0.31 to 0.90; nominal P=0.02). CONCLUSIONS: Over a period of 78 weeks, alirocumab, when added to statin therapy at the maximum tolerated dose, significantly reduced LDL cholesterol levels. In a post hoc analysis, there was evidence of a reduction in the rate of cardiovascular events with alirocumab. (Funded by Sanofi and Regeneron Pharmaceuticals; ODYSSEY LONG TERM ClinicalTrials.gov number, NCT01507831.).

Multiple biomarkers for the prediction of ischemic stroke: the PRIME study.

OBJECTIVE: To simultaneously evaluate 14 biomarkers from distinct biological pathways for risk prediction of ischemic stroke, including biomarkers of hemostasis, inflammation, and endothelial activation as well as chemokines and adipocytokines. METHODS AND RESULTS: The Prospective Epidemiological Study on Myocardial Infarction (PRIME) is a cohort of 9771 healthy men 50 to 59 years of age who were followed up over 10 years. In a nested case-control study, 95 ischemic stroke cases were matched with 190 controls. After multivariable adjustment for traditional risk factors, fibrinogen (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.03-2.28), E-selectin (OR, 1.76; 95% CI, 1.06-2.93), interferon-γ-inducible-protein-10 (OR, 1.72; 95% CI, 1.06-2.78), resistin (OR, 2.86; 95% CI, 1.30-6.27), and total adiponectin (OR, 1.82; 95% CI, 1.04-3.19) were significantly associated with ischemic stroke. Adding E-selectin and resistin to a traditional risk factor model significantly increased the area under the receiver-operating characteristic curve from 0.679 (95% CI, 0.612-0.745) to 0.785 and 0.788, respectively, and yielded a categorical net reclassification improvement of 29.9% (P=0.001) and 28.4% (P=0.002), respectively. Their simultaneous inclusion in the traditional risk factor model increased the area under the receiver-operating characteristic curve to 0.824 (95% CI, 0.770-0.877) and resulted in an net reclassification improvement of 41.4% (P<0.001). Results were confirmed when using continuous net reclassification improvement. CONCLUSIONS: Among multiple biomarkers from distinct biological pathways, E-selectin and resistin provided incremental and additive value to traditional risk factors in predicting ischemic stroke.

Description of a large family with autosomal dominant hypercholesterolemia associated with the APOE p.Leu167del mutation.

Apolipoprotein (apo) E mutants are associated with type III hyperlipoproteinemia characterized by high cholesterol and triglycerides levels. Autosomal dominant hypercholesterolemia (ADH), due to the mutations in the LDLR, APOB, or PCSK9 genes, is characterized by an isolated elevation of cholesterol due to the high levels of low-density lipoproteins (LDLs). We now report an exceptionally large family including 14 members with ADH. Through genome-wide mapping, analysis of regional/functional candidate genes, and whole exome sequencing, we identified a mutation in the APOE gene, c.500_502delTCC/p.Leu167del, previously reported associated with sea-blue histiocytosis and familial combined hyperlipidemia. We confirmed the involvement of the APOE p.Leu167del in ADH, with (1) a predicted destabilization of an alpha-helix in the binding domain, (2) a decreased apo E level in LDLs, and (3) a decreased catabolism of LDLs. Our results show that mutations in the APOE gene can be associated with bona fide ADH.

Adipocytokines and the risk of ischemic stroke: the PRIME Study.

OBJECTIVE: Adipocytokines are hormones secreted from adipose tissue that possibly link adiposity and the risk of cardiovascular disease, but limited prospective data exist on plasma adipocytokines and ischemic stroke risk. We investigated associations and predictive properties of 4 plasma adipocytokines, namely resistin, adipsin, leptin, and total adiponectin, with regard to incident ischemic stroke in the PRIME Study. METHODS: A cohort of 9,771 healthy men 50 to 59 years of age at baseline was followed up over a period of 10 years. In a nested case-control study, 95 ischemic stroke cases were matched with 190 controls on age, study center, and date of examination. Hazard ratios (HRs) per standard deviation increase in plasma adipocytokine levels were estimated using conditional logistic regression analysis. The additive value of adipocytokines in stroke risk prediction was evaluated by discrimination and reclassification metrics. RESULTS: Resistin (HR, 1.88; 95% confidence interval [CI], 1.16-3.03), adipsin (HR, 2.01; 95% CI, 1.33-3.04), and total adiponectin (HR, 1.53; 95% CI, 1.01-2.34), but not leptin, were independent predictors of ischemic stroke. The performance of a traditional risk factor model predicting ischemic stroke was significantly improved by the simultaneous inclusion of resistin, adipsin, and total adiponectin (c-statistic: 0.673 [95% CI, 0.631-0.766] vs 0.826 [95% CI, 0.792-0.892], p < 0.001; net reclassification improvement: 38.1%, p < 0.001). INTERPRETATION: Higher plasma levels of resistin, adipsin, and total adiponectin were associated with an increased 10-year risk of ischemic stroke among healthy middle-aged men. Resistin, adipsin, and total adiponectin provided incremental value over traditional risk factors for the prediction of ischemic stroke risk.

Mutations in PCSK9 cause autosomal dominant hypercholesterolemia.

Autosomal dominant hypercholesterolemia (ADH; OMIM144400), a risk factor for coronary heart disease, is characterized by an increase in low-density lipoprotein cholesterol levels that is associated with mutations in the genes LDLR (encoding low-density lipoprotein receptor) or APOB (encoding apolipoprotein B). We mapped a third locus associated with ADH, HCHOLA3 at 1p32, and now report two mutations in the gene PCSK9 (encoding proprotein convertase subtilisin/kexin type 9) that cause ADH. PCSK9 encodes NARC-1 (neural apoptosis regulated convertase), a newly identified human subtilase that is highly expressed in the liver and contributes to cholesterol homeostasis.

Molecular and functional analysis of two new MTTP gene mutations in an atypical case of abetalipoproteinemia.

Abetalipoproteinemia (ABL) is an inherited disease characterized by the defective assembly and secretion of apolipoprotein B-containing lipoproteins caused by mutations in the microsomal triglyceride transfer protein large subunit (MTP) gene (MTTP). We report here a female patient with an unusual clinical and biochemical ABL phenotype. She presented with severe liver injury, low levels of LDL-cholesterol, and subnormal levels of vitamin E, but only mild fat malabsorption and no retinitis pigmentosa or acanthocytosis. Our objective was to search for MTTP mutations and to determine the relationship between the genotype and this particular phenotype. The subject exhibited compound heterozygosity for two novel MTTP mutations: one missense mutation (p.Leu435His) and an intronic deletion (c.619-5_619-2del). COS-1 cells expressing the missense mutant protein exhibited negligible levels of MTP activity. In contrast, the minigene splicing reporter assay showed an incomplete splicing defect of the intronic deletion, with 26% of the normal splicing being maintained in the transfected HeLa cells. The small amount of MTP activity resulting from the residual normal splicing in the patient explains the atypical phenotype observed. Our investigation provides an example of a functional analysis of unclassified variations, which is an absolute necessity for the molecular diagnosis of atypical ABL cases.

C-reactive protein, interleukin 6, fibrinogen and risk of sudden death in European middle-aged men: the PRIME study.

OBJECTIVE: To examine prospectively the association of high-sensitivity C-reactive protein, interleukin 6, and fibrinogen with sudden death in asymptomatic European men. METHODS AND RESULTS: Among the 9771 men from the Etude PRospective de l'Infarctus du Myocarde (PRIME) Study, 664 had a first coronary heart disease over 10 years, including 50 sudden deaths, 34 nonsudden coronary deaths, and 580 nonfatal coronary heart disease events. For each outcome, 2 matched controls, who were free of coronary heart disease at the index date, were randomly selected from the initial cohort (nested case control study design). There was a 3-fold increased risk (95% CI, 1.20 to 7.81) of sudden death between the upper and the lower third of interleukin 6 after adjustment for baseline confounders in conditional logistic regression analysis. Neither high-sensitivity C-reactive protein (hazard ratio(third versus first tertile)=1.27; 95% CI, 0.51 to 3.17) nor fibrinogen (hazard ratio(third versus first tertile)=1.90; 95% CI, 0.76 to 4.75) was associated with sudden death. For comparison, there was a 6-fold increased risk of nonsudden coronary death from the highest compared with the lowest tertile of fibrinogen and a trend toward an association with higher C-reactive protein and higher interleukin 6. All 3 inflammatory biomarkers were moderately, but significantly, associated with nonfatal coronary heart disease. CONCLUSIONS: Interleukin 6, but not high-sensitivity C-reactive protein or fibrinogen, is an independent predictor of sudden death in asymptomatic European men.

Relative contribution of lipids and apolipoproteins to incident coronary heart disease and ischemic stroke: the PRIME Study.

AIM: To compare within the same cohort the association of a large panel of lipids with the risk of incident coronary heart disease (CHD) and ischemic stroke events in participants of the Prospective Epidemiological Study of Myocardial Infarction. METHODS: In this binational (Northern Ireland and France) prospective cohort, we considered 9,711 men aged 50-59 years free of CHD and stroke at baseline (1991-1993). The hazard ratios of each lipid marker for CHD and ischemic stroke events were estimated in separate Cox proportional hazard models adjusted for age, study center, systolic blood pressure, antihypertensive treatment, current smoking status, body mass index and diabetes. RESULTS: After 10 years of follow-up, 635 men had a first CHD and 98 a first ischemic stroke event. Total cholesterol (total-C), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), non-HDL-C, triglycerides, apolipoprotein (Apo) A1 and Apo B100, their ratios and lipoprotein (a) [Lp(a)] were all significantly predictive of future CHD. Associations with ischemic stroke followed the same trend as for CHD, but with lower strength, and none were statistically significant. However, none of the differences between the hazard ratios for CHD and for ischemic stroke were statistically significant. CONCLUSIONS: In healthy, middle-aged men, total-C, HDL-C, LDL-C, non-HDL-C, triglycerides, Apo A1 and Apo B100, their ratios and Lp(a) are, if anything, weak predictors of ischemic stroke events over a 10-year period.

Respective contribution of conventional risk factors and antihypertensive treatment to stable angina pectoris and acute coronary syndrome as the first presentation of coronary heart disease: the PRIME Study.

OBJECTIVE: To test whether conventional risk factors and antihypertensive treatment were more predictive of stable angina (SA) than acute coronary syndrome (ACS) as the first presentation of coronary heart disease (CHD). DESIGN: We used data from the PRIME Study (Prospective Epidemiological Study of Myocardial Infarction), a prospective cohort of 9758 asymptomatic middle-aged men recruited from WHO MONICA centers in Northern Ireland and France between 1991 and 1993. SA and ACS events were registered during 5 years of follow-up. METHODS: Hazard ratios (HRs) of each risk factor measured at baseline for SA and ACS events were assessed using separate Cox proportional hazard models. Difference between HRs was estimated by the bootstrap method. RESULTS: After 5 years of follow-up, there were 114 SA and 178 ACS as the first presentation of CHD. Diastolic blood pressure [adjusted HRs for 1 standard deviation increase = 1.34; 95% confidence interval (CI): 1.17-1.54 vs. 1.04; 95% CI: 0.87-1.25; P for comparison between HRs = 0.012], and possibly cigarette smoking over or equal to 20 pack-years (adjusted HR = 2.07; 95% CI: 1.43-2.99 vs. 1.29; 95% CI: 0.83-2.01; P for comparison between HRs = 0.062) were more predictive of ACS than SA, whereas this was the opposite for antihypertensive treatment (adjusted HR = 2.18; 95% CI: 1.39-3.41 for SA vs. 1.28; 95% CI: 0.85-1.93 for ACS, P for comparison between HRs = 0.049). CONCLUSION: The present data support that SA and ACS, as the first presentation of CHD, may not share exactly the same determinants.

Contribution of novel biomarkers to incident stable angina and acute coronary syndrome: the PRIME Study.

AIMS: To compare whether novel inflammatory and haemostatic biomarkers are more predictive of well-characterized incident acute coronary syndrome (ACS) than stable angina (SA). METHODS AND RESULTS: We used data from the PRIME Study, a prospective cohort of 9758 asymptomatic middle-aged men recruited in Northern Ireland and France between 1991 and 1993. A nested case-control study was established with the baseline plasma sample of 269 incident cases and 538 matched controls. Odds ratios (ORs) for SA and ACS were estimated by conditional logistic regression analysis. After 5 years of follow-up, 107 incident SA and 162 ACS cases were validated. After adjustment for traditional risk factors, higher circulating levels of hs-CRP, ICAM1, interleukin 6 and interleukin 18 were equally predictive of SA and ACS (all P-values of OR comparison >0.05). In contrast, elevated levels of fibrinogen, von Willebrand factor, and possibly higher level of D-dimers and lower level of tissue factor pathway inhibitor were associated with ACS only. The comparison of the ORs showed a statistically significant difference for von Willebrand factor only [OR(4th vs. 1st quartile) = 2.99 (1.49-6.02) for ACS vs. 0.80 (0.33-1.94) for SA; P(z test) = 0.02]. CONCLUSION: This is the first population-based study suggesting that higher levels of circulating haemostatic markers and of von Willebrand factor, in particular, are significantly more predictive of incident ACS than SA.

Small, qualitative changes in fatty acid intake decrease plasma low-density lipoprotein-cholesterol levels in mildly hypercholesterolemic outpatients on their usual high-fat diets.

OBJECTIVE: The diet is the first step in managing hypercholesterolemia. The objective of the present study is to assess whether moderate changes in dietary fatty acids improve plasma lipid parameters in mildly hypercholesterolemic outpatients. METHODS: Using a randomized double-blind study, 121 outpatients within two groups received an isocaloric amount of unsaturated margarine or butter. Clinical and anthropometric measurements and a 3-day food record were made. Chi-square and Fisher's tests were used to compare qualitative variables and the general linear procedure was used to compare the groups. Additional analyses were performed after adjustment. RESULTS: There was a significant difference (P <0.03) in low-density lipoprotein-cholesterol levels between the groups. Total cholesterol, low-density lipoprotein-cholesterol, non-high-density lipoprotein-cholesterol and apolipoprotein B values decreased in the unsaturated group in comparison with the saturated group. Low-density lipoprotein-cholesterol changes were correlated with the variation in polyunsaturated fatty acid intake and with plasma phospholipid linoleic acid levels. CONCLUSION: A small change in saturated by polyunsaturated fatty acid intake may improve plasma lipid parameters in mildly hypercholesterolemic subjects.

Epidemiology of out-of-hospital cardiac arrest: A French national incidence and mid-term survival rate study.

Out-of-hospital cardiac arrest (OHCA) is considered an important public health issue but its incidence has not been examined in France. The aim of this study is to define the incidence of OHCA in France and to compare this to other neighbouring countries. Data were extracted from the French OHCA registry. Only exhaustive centres during the period from January 1, 2013, to September 30, 2014 were included. All patients were included, regardless of their age and cause of OHCA. The participating centres covered about 10% of the French population. The study involved 6918 OHCA. The median age was 68 years, with 63% of males. Paediatric population (<15years) represented 1.8%. The global incidence of OHCA was 61.5 per 100,000 inhabitants per year in the total population corresponding to approximately 46,000 OHCA per year. In the adult population, we found an incidence of 75.3 cases per 100,000 inhabitants per year. In adults, the incidences were 100.3 and 52.7 in males and females, respectively. Most (75%) OHCA occurred at home and were due to medical causes (88%). Half of medical OHCA had cardiovascular causes. Survival rates at 30 days was 4.9% [4.4; 5.4] and increased to 10.4% [9.1; 11.7] when resuscitation was immediately performed by bystander at patient's collapse. The incidence and survival at 30 days of OHCA in France appeared similar to that reported in other European countries. Compared to other causes of deaths in France, OHCA is one of the most frequent causes, regardless of the initial pathology.

Lack of association between complement factor H polymorphisms and coronary artery disease or myocardial infarction.

Complement factor H (CFH) plays a critical role in the protection of host cells and tissues from damage by complement activation and has been suggested to protect against the progression of atherosclerosis. A polymorphism in the CFH gene, Y402H, known to be strongly associated with age-related macular degeneration, has been analyzed in relation to coronary artery disease (CAD) in several studies with conflicting results. We investigated the association of polymorphisms of the CFH gene in two large-scale studies on CAD and myocardial infarction (MI). The AtheroGene Study included a cohort of cases with CAD (n = 1,303) prospectively followed for a median period of 6.2 years, among whom198 experienced a cardiovascular event, and a group of 483 control subjects. The AtheroGene Study population was genotyped for the Y402H, I62V, and E936D polymorphisms. There was no significant difference in genotypic or allelic frequencies between CAD cases and controls. Among cases, no significant association was found with prospective cardiovascular outcome. Many inflammatory proteins, including the C-reactive protein, were measured, and none of the polymorphisms showed an association with these markers. The Etude Cas-Témoin de l'Infarctus du Myocarde (ECTIM) Study compared 1,034 patients with MI and 1,039 controls from France and United Kingdom. The ECTIM Study population was genotyped for the Y402H polymorphism. Genotype and allele frequencies were similar in cases and controls. These results do not support an involvement of common nonsynonymous polymorphisms of the CFH gene in predisposition to CAD and its complications.

Polymorphisms in 33 inflammatory genes and risk of myocardial infarction--a system genetics approach.

The hypothesis of a causal link between inflammation and atherosclerosis would be strengthened if variants of inflammatory genes were associated with disease. Polymorphisms of 33 genes encoding inflammatory molecules were tested for association with myocardial infarction (MI). Patients with MI and a parental history of MI (n = 312) and controls from the UK (n = 317) were genotyped for 162 polymorphisms. Thirteen polymorphisms were associated with MI (P values ranging from 0.003 to 0.041). For three genes, ITGB1, SELP, and TNFRSF1B haplotype frequencies differed between patients and controls (P values < 0.01). We further assessed the simultaneous contribution of all polymorphisms and relevant covariates to MI using a two-step strategy of data mining relying on Random Forest and DICE algorithms. In a replication study involving two independent samples from the UK (n = 649) and France (n = 706), one interaction between the ITGA4/R898Q polymorphism and current smoking status was replicated. This study illustrates a strategy for assessing the joint effect of a large number of polymorphisms on a phenotype that may provide information that single locus or single gene analysis may fail to uncover. Overall, there was weak evidence for an implication of inflammatory polymorphisms on susceptibility to MI.

Age discrimination in out-of-hospital cardiac arrest care: a case-control study.

BACKGROUND: Although some studies have questioned whether cardiopulmonary resuscitation (CPR) in older people could be futile, age is not considered an essential out-of-hospital cardiac arrest (OHCA) prognostic factor. However, in the daily clinical practice of mobile medical teams (MMTs), age seems to be an important factor affecting OHCA care. AIMS: The purpose of this study was to compare OHCA care and outcomes between young patients (<65 years old) and older patients. METHODS: We performed a case-control study based on data extracted from the French National Cardiac Arrest (CA) registry. All adult patients with CA recorded between July 2011 and May 2014 were included. Each older patient was matched on three criteria: sex, initial cardiac rhythm and no-flow duration. RESULTS: We studied 4347 pairs. We found significantly less basic life support initiation, shorter advanced cardiac life support duration, less MMT automated chest compression, less MMT ventilation and less MMT epinephrine injection in the older patients. Significant differences were also observed for return of spontaneous circulation (odds ratio (OR)=0.84, 95% confidence interval (CI) 0.77-0.92, p<0.001), transport to hospital (OR=0.58, 95% CI 0.51-0.61, p<0.001), vital status at hospital admission (OR=0.55, 95% CI 0.50-0.60, p<0.001) and vital status 30 days after CA (OR=0.42, 95% CI 0.35-0.50, p<0.001). CONCLUSION: All OHCA guidelines, ethical statements and clinical procedures do not propose age as a discrimination criterion in OHCA care. However, in our case-control study, we notice a shorter duration and less intensive care among older patients. This finding may partly explain the lower survival rate compared with younger people.

Usefulness of the genetic risk score to identify phenocopies in families with familial hypercholesterolemia?

Familial hypercholesterolemia (FH) is caused by mutations in LDLR (low-density lipoprotein receptor), APOB (apolipoprotein B), PCSK9 (proprotein convertase subtilisin/kexin type 9), or APOE (apolipoprotein E) genes in approximately 80% of the cases. Polygenic forms of hypercholesterolemia may be present among patients clinically diagnosed with FH but with no identified mutation (FH mutation-negative (FH/M-)). To address whether polygenic forms may explain phenocopies in FH families, we calculated a 6-single-nucleotide polymorphism (SNP) genetic risk score (GRS) in all members from five French FH families where a mutation was identified (FH/M+) as well as some phenocopies (FH/M-). In two families, three FH/M- patients present a high GRS suggesting a polygenic hypercholesterolemia for these phenocopies. However, a high GRS is also observed in nine FH/M+ patients and in four unaffected relatives from three families. These observations indicate that the GRS does not seem to be a good diagnostic tool at the individual level. Nevertheless, the GRS seems to be a contributor of the severity of hypercholesterolemia since patients who cumulate a mutation and a high GRS exhibit higher low-density lipoprotein cholesterol levels when compared to patients with only FH (p = 0.054) or only polygenic hypercholesterolemia (p = 0.0039). In conclusion, the GRS can be used as a marker of the severity of hypercholesterolemia but does not seem to be a reliable tool to distinguish phenocopies within FH families.

Cholesterol 7alpha-hydroxylase deficiency in mice on an APOE*3-Leiden background increases hepatic ABCA1 mRNA expression and HDL-cholesterol.

OBJECTIVE: High-density lipoprotein (HDL) plays a key role in protection against development of atherosclerosis by reducing inflammation, protecting against LDL oxidation, and promoting reverse cholesterol transport from peripheral tissues to the liver for secretion into bile. Cholesterol 7alpha-hydroxylase (Cyp7a1) catalyzes the rate-limiting step in the intrahepatic conversion of cholesterol to bile acids that may have a role in HDL metabolism. We investigated the effect of Cyp7a1 deficiency on HDL metabolism in APOE*3-Leiden transgenic mice. METHODS AND RESULTS: Reduced bile acid biosynthesis in Cyp7a1-/-.APOE*3-Leiden mice versus APOE*3-Leiden mice did not affect total plasma cholesterol levels, but the distribution of cholesterol over various lipoproteins was different. Cholesterol was decreased in apoB-containing lipoproteins (ie, VLDL and IDL/LDL), whereas cholesterol was increased in HDL. The activity of PLTP and LCAT, which play a role in HDL catabolism, were not changed, and neither was HDL clearance. However, the hepatic cholesterol content was 2-fold increased, which was accompanied by a 2-fold elevated expression of hepatic ABCA1 and increased rate of cholesterol efflux from the liver to HDL. CONCLUSIONS: Strongly reduced bile acid synthesis in Cyp7a1-/-.APOE*3-Leiden mice leads to increased plasma HDL-cholesterol levels, as related to an increased hepatic expression of ABCA1.

Palmitic acid in HDL is associated to low apo A-I fractional catabolic rates in vivo.

BACKGROUND: HDL becomes enriched with non-esterified fatty acids (NEFAs) in some pathologies, such as nephrotic syndrome, as well as after aerobic exercise. However, little is known about the impact of NEFAs on HDL metabolism. We investigated the effects of one NEFA, the palmitic acid, on HDL structure and catabolism. METHODS: HDL enrichment with palmitic acid (HDLPal) was performed by fusing phosphatidyl choline small unilamellar vesicles containing the NEFA with human HDL isolated from a pool of 5 normolipidemic plasma. HDL enriched only with phosphatidyl choline (HDLPhl) and native HDL (HDLCtrl) were included as controls. RESULTS: As expected, HDLPal surface charge density was higher than HDLPhl and HDLCtrl (2014.4+/-164.8 vs. 1682.7+/-149.5 and 1758.2+/-124.3-esu/cm2, respectively, p<0.05). Both, HDLPal and HDLPhl were better substrates for cholesteryl esters transfer protein (CETP) than HDLCtrl (% of transfer, 13.02+/-3.8 and 12.7+/-4.5 vs. 7.8+/-2.7% in 16 h, respectively, p<0.05). HDLPal apo A-I catabolism in vivo, as performed in New Zealand white rabbits by exogenous radiolabeling, was markedly lower than that of HDLPhl and HDLCtrl (fractional catabolic rate, 0.019+/-0.008 vs. 0.030+/-0.005 and 0.047+/-0.003 h-1, respectively, p<0.001), suggesting that negative charge is inversely related to HDL-apo A-I catabolism. CONCLUSIONS: Enrichment with palmitic acid increases the negative electric charge of HDL at physiological pH, contributes to decrease their catabolism, and is associated to an enhanced lipid transfer by CETP that has been related to the atherogenic process.

Plasma cystatin-C and development of coronary heart disease: The PRIME Study.

The pathogenesis of ischemic coronary events involves degradation of the extracellular matrix in atherosclerotic lesions. The cysteine protease inhibitor cystatin-C may be involved in this phenomenon. The association of plasma cystatin-C with the incidence of myocardial infarction-coronary death and angina, was examined in a nested case-control (two controls per case) design within the prospective cohort study (Prospective Epidemiological Study of Myocardial Infarction (PRIME Study)) which included 9,758 men aged 50-59 years who were free of coronary heart disease (CHD) on entry and followed for a 5-year period. Three hundred and thirteen participants suffered myocardial infarction or coronary death (n = 159) or angina pectoris (n = 154) during follow-up. Cystatin-C was positively correlated with body mass index (BMI), low-density lipoprotein (LDL)-cholesterol, triglycerides and several inflammatory markers such as fibrinogen (r = 0.18), C-reactive protein (CRP) (r = 0.24), interleukin-6 (= 0.20), tumor necrosis factor-alpha (TNFalpha) (r = 0.27) and two TNFalpha receptors: TNFR1A (r = 0.43) and TNFR1B (r = 0.41); and negatively with high-density lipoprotein (HDL)-cholesterol (r = -0.25). After adjustment for traditional risk factors (age, diabetes, smoking, hypertension, BMI, triglycerides, LDL- and HDL-cholesterol), cystatin-C was significantly associated with the occurrence of the first ischemic coronary event. However, this association was no longer significant when CRP was included in the analysis. A decrease in glomerular filtration rate did not explain higher cystatin-C in cases than in controls. Cystatin-C appears to participate in the inflammatory phenomenon observed in the atherosclerotic process. Cystatin-C is not a more predictive risk marker of CHD than CRP or interleukin-6, but could be useful in detecting moderate chronic renal disease.

Different VLDL apo B, and HDL apo AI and apo AII metabolism in two heterozygous carriers of unrelated mutations in the lipoprotein lipase gene.

BACKGROUND: Lipoprotein lipase (LPL) deficiency has been suggested as a cause of low HDL-cholesterol (HDL-C) plasma levels, by a mechanism that involves an enhanced catabolism of HDL apolipoprotein (apo) AI. To verify the role of 2 different LPL gene mutations on HDL metabolism, we studied the in vivo turnover of the apo AI and apo AII in heterozygous carriers of LPL deficiency. METHODS: Apo AI and AII kinetics were studied by a 10-h primed constant infusion of 5,5,5-2H3-leucine approach in 2 carriers, 1 man (patient 1) and 1 woman (patient 2), and 5 control subjects. The rates of HDL apolipoproteins production (PR) and catabolism (FCR) were estimated using a one-compartment model-based analysis. RESULTS: Both carriers had low HDL-C plasma levels and only patient 1 was hypertriglyceridemic. VLDL apo B was 4-times slower in patient 1 as compared to patient 2. The FCRs of apo AI in both carriers was within the range of the controls (0.200, 0.221 and 0.211+/-0.051 day(-1), respectively). Apo AII FCR in patient 1 was about 20% lower than the mean of the control group whereas being normal in patient 2. Apo AI PR in patient 1 (9.20 mg kg(-1) day(-1)) was below the lowest value in controls (range, 10.52-13.24 mg kg(-1) day(-1)) whereas in patient 2 it was normal. Apo AII PR in both patients was similar to controls. CONCLUSION: The heterozygous carriers of 2 different mutations in the LPL gene had different VLDL apo B FCR, and from normal to slightly low HDL apolipoprotein FCR and PR. These results disagree with the putative enhanced apo AI FCR in LPL deficient patients and suggest the need to reconsider the effects of LPL activity on HDL metabolism.