Biomedical subjects

John J P Kastelein

Publications and source records attributed to John J P Kastelein.

At least 19 recordsLinked to original sources

PubMed2026

Drug targets for lipid modification and risk of type 2 diabetes: a cis-Mendelian randomization study.

BACKGROUND AND AIMS: Reducing plasma levels of low-density lipoprotein cholesterol (LDL-C) is the cornerstone in the prevention of coronary artery disease (CAD) but may also increase risk of type 2 diabetes (T2D). A comprehensive examination of the genetic evidence of T2D related side-effects of all current lipid-modifying drugs, including those in development, has not yet been performed. METHODS: This cis-Mendelian randomization study used individual level data from the UK Biobank, Lifelines, and publicly available genome-wide association data. We identified loci that are either targeted directly with drugs, or alternatively, targeting their gene products (mRNA and/or protein). Included are, in alphabetical order, the loci ACLY, ANGPTL3, ANGPTL4, APOB, APOC3, CETP, HMGCR, LDLR, LIPG, LPA, MTTP, NPC1L1, and PCSK9. We used cis-genetic instruments weighted for LDL-C, HDL-C, triglycerides, and apolipoproteins as downstream proxies for the drug targets. Main outcomes were prevalent and incident T2D, with CAD as a contrast outcome. RESULTS: Lipid modification through HMGCR is predicted to reduce CAD risk and increase T2D risk. Modification through targeting APOC3, LDLR, LPA, MTTP, NPC1L1, and PCSK9 is predicted to reduce CAD risk without a change in T2D risk. Modification through ANGPTL4 and CETP is predicted to reduce risk of both CAD and T2D. For ACLY, ANGPTL3, APOB, and LIPG, we found evidence for neither CAD nor T2D. CONCLUSIONS: This study provides genetic evidence for variation in diabetes-related side-effects of different lipid-modifying drugs, with potential relevance for future clinical trials and individual treatment decisions.

Humans↗

PubMed2006

Cholesteryl ester transfer protein and hyperalphalipoproteinemia in Caucasians.

It is unclear whether cholesteryl ester transfer protein (CETP) contributes to high density lipoprotein cholesterol (HDL-C) levels in hyperalphalipoproteinemia (HALP) in Caucasians. Moreover, even less is known about the effects of hereditary CETP deficiency in non-Japanese. We studied 95 unrelated Caucasian individuals with HALP. No correlations between CETP concentration or activity and HDL-C were identified. Screening for CETP gene defects led to the identification of heterozygosity for a novel splice site mutation in one individual. Twenty-five heterozygotes for this mutation showed reduced CETP concentration (-40%) and activity (-50%) and a 35% increase of HDL-C compared with family controls. The heterozygotes presented with an isolated high HDL-C, whereas the remaining subjects exhibited a typical high HDL-C/low-triglyceride phenotype. The increase of HDL-C in the CETP-deficient heterozygotes was primarily attributable to increased high density lipoprotein containing apolipoprotein A-I and A-II (LpAI:AII) levels, contrasting with an increase in both high density lipoprotein containing apolipoprotein A-I only and LpAI:AII in the other group. This study suggests the absence of a relationship between CETP and HDL-C levels in Caucasians with HALP. The data furthermore indicate that genetic CETP deficiency is rare among Caucasians and that this disorder presents with a phenotype that is different from that of subjects with HALP who have no mutation in the CETP gene.

Adult↗

PubMed2006

Adherence to evidence-based statin guidelines reduces the risk of hospitalizations for acute myocardial infarction by 40%: a cohort study.

AIMS: To investigate the 'real world' effectiveness of robust statin therapy, focusing on the effect of dose and early treatment discontinuation on the risk of hospitalization for acute myocardial infarction (AMI). METHODS AND RESULTS: In the PHARMO database, including among others drug-dispensing and hospital discharge records for more than two million subjects in the Netherlands, 59,094 new users of statins in the period 1 January 1991 until 31 December 2004, >or=18 years of age were identified. In these patients, exposure to statins, both in terms of persistence and dose, was determined over the first two treatment years. To determine the risk for AMI, patients were followed from this 2-year time point until the first hospital admission for AMI, death, or end of the study period. A total of 31,557 patients (53%) discontinued statin use within 2 years; 20 883 patients (35%) were persistent users with an average equipotent dose>or=4. A 30% reduction in risk of hospitalization for AMI with persistent statin use was observed. The protective effect increased with a higher dose (20 and 40% risk reduction with an equipotent dose or=4, respectively). CONCLUSION: These results show that statins are suboptimally used in real life for having the maximum benefit in terms of preventing AMI.

Adult↗

PubMed2006

Low plasma adiponectin exacerbates the risk of premature coronary artery disease in familial hypercholesterolemia.

Familial hypercholesterolemia (FH) is characterized by increased risk for premature coronary artery disease (CAD). This risk is exacerbated in the presence of abdominal obesity and insulin resistance. Low adiponectin is part of the clustering of metabolic abnormalities associated with abdominal obesity and insulin resistance. The present study, therefore, aims to examine the relationship between plasma adiponectin and age at CAD diagnosis in FH patients. Plasma adiponectin was measured by ELISA in 568 non-diabetic FH individuals of French-Canadian origin. CAD was defined according to strict clinical criteria. Prior to analyses, patients were grouped according to age and gender-specific tertiles of plasma adiponectin levels. Multivariate Cox proportional hazards regression was used to estimate the association between plasma adiponectin levels and age at diagnosis of CAD. Overall, FH patients in the lowest tertile of plasma adiponectin exhibited CAD at a significantly younger age (hazard ratio=1.73, confidence interval 95%: [1.19-2.53]; p=0.004). These results suggest that low plasma adiponectin is associated with an increased risk of premature CAD over and above the already exaggerated risk seen in FH patients.

Adiponectin↗

PubMed2006

Adeno-associated virus LPL(S447X) gene therapy in LDL receptor knockout mice.

BACKGROUND: Overexpression of lipoprotein lipase (LPL) protects against atherosclerosis in genetically engineered mice. We tested whether a gene therapy vector that delivers human (h) LPL(S447X) cDNA to skeletal muscle could induce similar effects. METHODS: LDL receptor knockout (LDLr-/-) mice were injected intramuscular (i.m.) with adeno-associated virus serotype 1 (AAV1) LPL(S447X) or PBS. Four weeks later they were started on an atherogenic diet for 12 weeks. After termination, atherosclerosis was assessed and homogenates of muscle and liver tissue were analyzed. RESULTS: AAV1-treated mice showed hLPL concentrations of 768+/-293 ng/mL in post-heparin plasma associated with 48% reductions of fasting triglycerides (TG) levels (p<0.0001). In the absence of an effect on total cholesterol (TC) levels, no effects on atherosclerosis were found. An increase in lipid content of injected muscles was accompanied by a significant decrease of TG (-20%, p<0.0001) and free cholesterol (FC) content (-24%, p<0.0001) in liver homogenates. CONCLUSIONS: The data show that transgenic hLPL(S447X) on top of endogenous murine LPL reduces fasting TG levels in plasma but has no effect on atherosclerosis in LDLr-/- mice. While lipid accumulation in the injected muscle was anticipated, this coincided with an interesting decrease of both TG and FC in liver homogenates.

Animals↗

PubMed2006

Influence of LDL-receptor mutation type on age at first cardiovascular event in patients with familial hypercholesterolaemia.

AIMS: To investigate the influence of different LDL-receptor (LDLR) gene mutations on age at first cardiovascular event in familial hypercholesterolaemia (FH) patients. METHODS AND RESULTS: Dutch FH patients (n = 862) with known LDLR mutations from a retrospective cohort study were included. A gamma frailty Cox model was used. An event was defined as the first cardiovascular event. Gender, hypertension, smoking, diabetes, HDL cholesterol, LDL cholesterol (LDL-C), or triglycerides were included as covariates. Furthermore, the effect of LDLR mutation type on LDL and HDL cholesterol levels was investigated using mixed effects models, including gender, smoking, body mass index, and age at time of lipid measurement as covariates. A total of 86 different LDLR mutations were present in this cohort. Twenty-two percent of patients experienced an event (median age: 47.1 year; range: 25.6-85.8 years). The effect of LDLR mutation type on event-free survival is only significant in the models without LDL-C levels. Also, LDLR mutation type was significantly associated with LDL-C levels (P = 0.007), but not with HDL cholesterol levels (P = 0.12). CONCLUSION: In the present study, LDL-C levels are a more important risk factor of event-free survival than the type of LDLR mutation.

Adult↗

PubMed2006

Plasma levels of plant sterols and the risk of coronary artery disease: the prospective EPIC-Norfolk Population Study.

Some studies have suggested that a modest increase of plant sterol levels is a risk factor for coronary artery disease (CAD). We studied the relationship between plant sterol levels and CAD risk in a prospective nested case-control study consisting of 373 cases and 758 controls. Sitosterol and campesterol concentrations did not differ between cases and controls [sitosterol, 0.21 vs. 0.21 mg/dl (P = 0.1); campesterol, 0.31 vs. 0.32 mg/dl (P = 0.5)]. The sitosterol-to-cholesterol ratio was significantly lower in cases than in controls (1.19 vs. 1.29 microg/mg; P = 0.008), whereas the campesterol-to-cholesterol ratio did not differ significantly (1.78 vs. 1.88 microg/mg; P = 0.1). Plant sterol concentrations correlated positively with cholesterol levels and inversely with body mass index and triglyceride and lathosterol concentrations. Among individuals in the highest tertile of the sitosterol concentration, the unadjusted odds ratio (OR) for future CAD was 0.75 [95% confidence interval (CI) = 0.56-1.01]. After adjustment for traditional risk factors, the OR was 0.79 (95% CI = 0.56-1.13). For the campesterol concentration, the unadjusted OR was 0.95 (95% CI = 0.71-1.29) and the adjusted OR was 0.97 (95% CI = 0.68-1.39). In this large prospective study, higher levels of plant sterols, at least in the physiological range, do not appear to be adversely related to CAD in apparently healthy individuals.

Aged↗

PubMed2006

Relative risk for cardiovascular atherosclerotic events after smoking cessation: 6-9 years excess risk in individuals with familial hypercholesterolemia.

BACKGROUND: Smoking history is often di- or trichotomized into for example "never, ever or current smoking". However, smoking must be treated as a time-dependent covariate when lifetime data is available. In particular, individuals do not smoke at birth, there is usually a wide variation with respect to smoking history, and smoking cessation must also be considered. METHODS: Therefore we analyzed smoking as a time-dependent risk factor for cardiovascular atherosclerotic events in a cohort of 2400 individuals with familial hypercholesterolemia who were followed from birth until 2004. Excess risk after smoking-cessation was modelled in a Cox regression model with linear and exponential decaying trends. The model with the highest likelihood value was used to estimate the decay of the excess risk of smoking. RESULTS: Atherosclerotic events were observed in 779 patients with familial hypercholesterolemia and 1569 individuals had a smoking history. In the model with the highest likelihood value the risk reduction of smoking after cessation follows a linear pattern with time and it appears to take 6 to 9 years before the excess risk is reduced to zero. The risk of atherosclerotic events due to smoking was estimated as 2.1 (95% confidence interval 1.5; 2.9). CONCLUSION: It was concluded that excess risk due to smoking declined linearly after cessation in at least six to nine years.

Aged↗

PubMed2006

Effects of high-dose atorvastatin on cerebrovascular events in patients with stable coronary disease in the TNT (treating to new targets) study.

OBJECTIVE: We sought to assess the effects on cerebrovascular events of treating patients with stable coronary disease with low-density lipoprotein cholesterol (LDL-C) levels substantially below 100 mg/dl. BACKGROUND: Lowering LDL-C with statins has been shown to reduce the risk of stroke in patients with stable coronary disease. In observational studies, naturally low cholesterol levels have been associated with an increased risk of hemorrhagic stroke. The cerebrovascular benefits of treating patients with stable coronary disease to LDL-C levels substantially below 100 mg/dl have not been previously investigated. METHODS: We describe an analysis of cerebrovascular events in the Treating to New Targets study, a trial where 10,001 patients with documented coronary disease were randomized to treatment with atorvastatin at 10 mg/day or 80 mg/day and followed for a median of 4.9 years. RESULTS: Mean LDL-C levels were 101 mg/dl on 10 mg atorvastatin and 77 mg/dl on 80 mg. In addition to the reduction in major cardiovascular events (hazard ratio 0.78, 95% confidence interval [CI] 0.69 to 0.89; p = 0.0002), the primary end point of the trial, patients in the 80-mg arm experienced a reduction in cerebrovascular events (hazard ratio 0.77, 95% CI 0.64 to 0.93; p = 0.007) and stroke (hazard ratio 0.75, 95% CI 0.59 to 0.96; p = 0.02). Each 1-mg/dl reduction in LDL-C with treatment was associated with a 0.6% relative risk reduction in cerebrovascular events (p = 0.002) and a 0.5% relative risk reduction in stroke (p = 0.041). The incidence of hemorrhagic stroke was similar in the 80-mg and 10-mg groups, 16 and 18 respectively, and the hemorrhagic strokes were distributed evenly across quintiles of achieved LDL-C during treatment. CONCLUSIONS: Among patients with established coronary disease, treating to an LDL-cholesterol substantially below 100 mg/dl with 80 mg/day atorvastatin reduces both stroke and cerebrovascular events by an additional 20% to 25% compared with the 10 mg/day dose. An increase in hemorrhagic stroke was not seen at low LDL-C levels. (Treating to New Targets; http://www.clinicaltrials.gov; NCT00327691).

Aged↗

PubMed2006

Potent reduction of apolipoprotein B and low-density lipoprotein cholesterol by short-term administration of an antisense inhibitor of apolipoprotein B.

BACKGROUND: Apolipoprotein B (apoB) is an important structural component of low-density lipoprotein cholesterol (LDL-C) and plays a key role in LDL-C transport and removal. Reduction in apoB synthesis is expected to reduce circulating LDL-C, a proven risk factor of cardiovascular disease. In the present study, we describe the outcome of the first-in-humans study on the safety and efficacy of an antisense oligonucleotide inhibitor of apoB. METHODS AND RESULTS: This study was a double-blind, randomized, placebo-controlled, dose-escalation investigation conducted at a single site in 36 volunteers with mild dyslipidemia. The study utilized an initial single dose of 50 to 400 mg of ISIS 301012, a 20-mer oligonucleotide, followed by a 4-week multiple-dosing regimen with the same assigned dose. Safety was assessed by the incidence, severity, and relationship of adverse events to dose. Efficacy was determined by changes in serum apoB and LDL-C relative to baseline and placebo. The most common adverse event was erythema at the injection site (21 of 29 subjects). ApoB was reduced by a maximum of 50% (P=0.002) from baseline in the 200-mg cohort. This decrease in apoB coincided with a maximum 35% reduction of LDL-C (P=0.001). LDL-C and apoB remained significantly below baseline (P<0.05) up to 3 months after the last dose. CONCLUSIONS: Administration of an antisense oligonucleotide to human apoB resulted in a significant, prolonged, and dose-dependent reduction in apoB and LDL-C. Although injection-site reactions were common, adherence to protocol was unaffected.

Adult↗

PubMed2006

Enhanced apoB48 metabolism in lipoprotein lipase X447 homozygotes.

RATIONALE: Lipoprotein lipase (LPL) X447 homozygotes are characterized by enhanced conversion of TRL apoB100. Here, we set out to investigate whether this LPL variant is also associated with enhanced apoB48 clearance. Therefore, we evaluated apoB48 kinetics in X447 homozygotes in the fed state by infusion of isotope L-[1-(13)C]-valine and subsequent compartmental modeling. METHODS AND RESULTS: ApoB48 metabolism was assessed in five X447 homozygotes (X/X genotype) and five S447 homozygotes (S/S genotype). Subjects were continuously fed and received infusion of stable isotope L-[1-(13)C]-valine. Results were analyzed by SAAM II modeling. Fasting (2.4-fold, p=0.02) as well as non-fasting (1.6-fold, p=0.09) apoB48 concentration was increased in the X447 homozygotes compared to S447 homozygotes. In addition, the X447 homozygotes exhibited a 1.7-fold higher apoB48 poolsize (p=0.04). Interestingly, apoB48 fractional catabolic rate (FCR) was 1.9-fold higher (p=0.007) and apoB48 synthesis was more than two-fold higher (p=0.006) in the X447 homozygotes compared to S447 homozygotes. CONCLUSION: In the present study, we show that X447 homozygotes exhibit enhanced apoB48 clearance. Previously, these homozygotes were shown to present with enhanced apoB100 TRL conversion. Combined, this LPLS447X gain of function variant affects apoB48 as well as apoB100 TRL metabolism.

Apolipoprotein B-48↗

PubMed2006

Reduction of low-density lipoprotein cholesterol in patients with coronary heart disease and metabolic syndrome: analysis of the Treating to New Targets study.

BACKGROUND: Despite the prognostic value of metabolic syndrome for predicting cardiovascular events, few trials have investigated the effects of statin therapy on cardiovascular morbidity and mortality in patients with the metabolic syndrome. Our post hoc analysis of the Treating to New Targets (TNT) study assessed whether intensive lowering of low-density lipoprotein cholesterol with high-dose atorvastatin therapy results in cardiovascular benefits for patients with both coronary heart disease and the metabolic syndrome. METHODS: The TNT study was a prospective, double blind, parallel-group trial done at 256 sites in 14 countries between April, 1998, and August, 2004, with a median follow-up of 4.9 years. 10,001 patients were enrolled aged 35-75 years with clinically evident coronary heart disease. Our analysis includes 5584 patients with metabolic syndrome based on the 2005 NCEP ATP III criteria. Patients were randomly assigned to receive either atorvastatin 10 mg per day (n=2820) or 80 mg per day (n=2764). The primary outcome measure was time to first major cardiovascular event, defined as death from coronary heart disease, non-fatal non-procedure-related myocardial infarction, resuscitated cardiac arrest, or fatal or non-fatal stroke. FINDINGS: In patients with coronary heart disease and metabolic syndrome, mean on-treatment low-density lipoprotein cholesterol concentrations at 3 months were 2.6 mmol/L (99.3 mg/dL) with atorvastatin 10 mg, and 1.9 mmol/L (72.6 mg/dL) with atorvastatin 80 mg. At a median follow-up of 4.9 years, major cardiovascular events occurred in 367 (13%) patients receiving atorvastatin 10 mg, compared with 262 (9.5%) receiving atorvastatin 80 mg (hazard ratio 0.71; 95% CI 0.61-0.84; p<0.0001). Irrespective of treatment assignment, significantly more patients with metabolic syndrome (11.3%) had a major cardiovascular event at a median of 4.9 years than those without metabolic syndrome (8.0%; hazard ratio 1.44; 95% CI 1.26-1.64; p<0.0001). This increased risk was significantly reduced by intensive therapy with atorvastatin 80 mg beyond that achieved with atorvastatin 10 mg. INTERPRETATION: These data indicate that patients with coronary heart disease and metabolic syndrome derive incremental benefit from high-dose atorvastatin therapy, irrespective of the presence of diabetes.

Adult↗

PubMed2006

AAV1-LPL(S447X) gene therapy reduces hypertriglyceridemia in apoE2 knock in mice.

UNLABELLED: Intramuscular (IM) application of adeno-associated virus serotype 1 (AAV1) for the delivery of human lipoprotein lipase (hLPL) was previously shown efficacious in mice with chylomicronemia. The current study addresses whether AAV1-LPL(S447X) can reduce elevated triglyceride (TG) levels in mice with attenuated clearance of TG-rich remnant particles. METHODS: Female mice, expressing human apoE2 but deficient for endogenous apoE (apoE2KI) received IM injections of AAV1-LPL(S447X) (n=6; 8 x 10(12) gc/kg; 4-sites) or PBS (n=5). Following lipid monitoring, the mice were challenged with intravenous Intralipid injections, and sacrificed 3 months after treatment. RESULTS: In the mice that received LPL gene therapy, a marked increase of post-heparin hLPL protein levels (averaging 517+/-277 ng/mL vs. 4+/-3 ng/mL in apoE2KI-untreated) induced 20% reductions of fasting plasma TG levels (p<0.05). This was accompanied by two-fold increased TG clearance rates after Intralipid administration at 6 weeks after treatment (p<0.05). Post-mortem analyses revealed increased levels of TG (2-fold, p<0.005) and cholesterol (1.7-fold, p<0.001) in the treated muscles. CONCLUSIONS: IM application of AAV1-LPL(S447X) is effective in reducing TG levels in a mouse model for type III dyslipidemia. Thus, hypertriglyceridemia caused by attenuated uptake of TG-rich lipoproteins can be alleviated by increasing lipolytic function of the skeletal muscle tissue.

Animals↗

PubMed2006

A functional polymorphism in the glucocorticoid receptor gene and its relation to cardiovascular disease risk in familial hypercholesterolemia.

CONTEXT: Individuals with the functional ER22/23EK variant in the glucocorticoid receptor gene are relatively resistant to the downstream consequences of glucocorticoids. Evidence suggests that carriers have a more favorable cardiovascular risk profile, but the relationship between this ER22/23EK variant and cardiovascular disease has not been hitherto assessed. OBJECTIVE: We, therefore, determined whether carriership of the ER22/23EK improves cardiovascular disease risk in patients with severe hypercholesterolemia. DESIGN, SETTING, AND PARTICIPANTS: In a multicenter cohort study, 2024 patients with heterozygous familial hypercholesterolemia, aged 18 yr and older, were genotyped for the ER22/23EK polymorphism. Patients were identified at lipid clinics throughout The Netherlands between 1989 and 2002. MAIN OUTCOME MEASURES: The primary outcome measure was cardiovascular disease. RESULTS: Seventy-six (7.8%) of 977 men and 72 (6.9%) of 1047 women were carriers of the ER22/23EK variant. A total of 395 men and 247 women had a cardiovascular event. In contrast to expected results, we observed no significant association of the ER22/23EK variant with cardiovascular disease risk (men: relative risk, 0.75; 95% confidence interval, 0.50-1.14; P = 0.2; women: relative risk, 1.37; 95% confidence interval, 0.82-2.28; P = 0.2). However, we found a significant interaction between gender and the polymorphism on cardiovascular disease (P = 0.02). CONCLUSIONS: In this large cohort of individuals with very high risk of cardiovascular disease, the association between the functional ER22/23EK polymorphism and cardiovascular risk was not significant overall, although it varied significantly by gender.

Adult↗

PubMed2006

Diagnosing familial hypercholesterolaemia: the relevance of genetic testing.

AIMS: We assembled a cohort of patients with familial hypercholesterolaemia (FH) for both basic and clinical research. We used a set of established diagnostic criteria to define FH. Some put forward that a definite diagnosis of FH is made when a mutation in the LDL-receptor (LDLR) gene is identified. We therefore set out to determine in these patients whether patients with a DNA diagnosis would differ significantly from those diagnosed clinically. METHODS AND RESULTS: We randomly selected 4000 hypercholesterolaemic patients from the Dutch Lipid Clinic network database. Phenotypical data were acquired by reviewing medical records. After review of medical records, 2400 patients could be defined as having FH. An LDLR mutation was identified in 52.3% of these patients. Patients with and without an LDLR mutation demonstrated different clinical and laboratory characteristics. Low-density lipoprotein cholesterol was higher in patients with an LDLR mutation, whereas triglycerides were higher in patients without an LDLR mutation. The phenotypic differences between the groups remained even after stratification for the presence or absence of tendon xanthomas. CONCLUSION: Despite the use of stringent clinical criteria to define FH patients, two cohorts could be identified within our study population, namely those patients with and those without an LDLR mutation. Our findings suggest that among those without an LDLR mutation, patients with other causes of dyslipidaemia may be present. These observations underline the relevance of genetic testing in FH for clinical practice, for screening purposes, and for research involving these patients.

Adult↗

PubMed2006

Apolipoprotein A-V, triglycerides and risk of coronary artery disease: the prospective Epic-Norfolk Population Study.

In mouse models, apolipoprotein A-V (apoA-V) exhibits triglyceride (TG)-lowering effects. We investigated the apoA-V/TG relationship and the association of apoA-V with coronary artery disease (CAD) risk by determining serum apoA-V levels and genotypes in a nested case-control (n = 1,034/2,031) study. Both univariate and multivariate apoA-V levels showed no association with future CAD (P = 0.4 and 0.5, respectively). Unexpectedly, there was a significant positive correlation between serum apoA-V and TG in men and women (r = 0.36 and 0.28, respectively, P < 0.001 each) but a negative correlation between apoA-V and LPL mass (r = -0.14 and -0.12 for men and women respectively, P < 0.001 each). The frequency of the c.56C>G polymorphism did not differ between cases and controls despite significant positive association of c.56G with both apoA-V and TG levels. For -1131T>C, the minor allele was significantly associated with lower apoA-V yet higher TG levels and was overrepresented in cases (P = 0.047). The association of -1131T>C with CAD risk, however, was independent of apoA-V levels and likely acts through linkage disequilibrium with APOC3 variants. The positive correlation of apoA-V levels with TG levels, negative correlation with LPL levels, and lack of association with CAD risk highlight the need for further human studies to clarify the role of apoA-V.

Aged↗

PubMed2006

Oxidized low-density lipoprotein in children with familial hypercholesterolemia and unaffected siblings: effect of pravastatin.

OBJECTIVES: To assess the role of oxidized phospholipids (OxPLs) in children with familial hypercholesterolemia (FH) and the effect of pravastatin. BACKGROUND: Oxidized phospholipids are a major component of oxidized low-density lipoprotein (OxLDL) and are bound to lipoprotein (a) [Lp(a)]. The significance of OxPL markers in children is unknown. METHODS: Children with FH were randomized to placebo (n = 88) or pravastatin (n = 90) after instruction on American Heart Association step II diet. Unaffected siblings (n = 78) served as controls. The OxPL content on apolipoprotein B-100 (apoB) detected by antibody E06 (OxPL/apoB ratio), immunoglobulin (Ig)G and IgM immune complexes per apoB (IC/apoB) and on all apoB particles (total apoB-IC = IC/apoB multiplied by plasma apoB levels), autoantibodies to malondialdehyde (MDA)-low-density lipoprotein (LDL), Lp(a), and apoB levels were measured at baseline and after two years of treatment. RESULTS: Compared with unaffected siblings, children with FH had significantly lower levels of OxPL/apoB but higher levels of IgG and IgM total apoB-IC and IgM MDA-LDL autoantibodies. From baseline to two-year follow-up, compared with placebo pravastatin treatment resulted in a greater mean percentage change in apoB (-18.7% vs. 0.3%; p = 0.001), total IgG apoB-IC (-31.9% vs. -12.2%; p < 0.001), and total IgM apoB-IC (-25.5% vs. 13.2%; p = 0.001). Interestingly, pravastatin also resulted in higher OxPL/apoB (48.7% vs. 29.3%; p = 0.028) and Lp(a) levels (21.9% vs. 10.7%; p = 0.044). CONCLUSIONS: Compared with unaffected siblings, children with FH are characterized by elevated levels of apoB-IC and IgM MDA-LDL autoantibodies. Compared with placebo, pravastatin led to a greater reduction in apoB-IC but also to a greater increase in OxPL/apoB and Lp(a), which may represent a novel mechanism of mobilization and clearance of OxPL.

Anticholesteremic Agents↗

PubMed2006

Lipoprotein lipase S447X: a naturally occurring gain-of-function mutation.

Lipoprotein lipase (LPL) hydrolyzes triglycerides in the circulation and promotes the hepatic uptake of remnant lipoproteins. Since the gene was cloned in 1989, more than 100 LPL gene mutations have been identified, the majority of which cause loss of enzymatic function. In contrast to this, the naturally occurring LPL(S447X) variant is associated with increased lipolytic function and an anti-atherogenic lipid profile and can therefore be regarded as a gain-of-function mutation. This notion combined with the facts that 20% of the general population carries this prematurely truncated LPL and that it may protect against cardiovascular disease has led to extensive clinical and basic research into this frequent LPL mutant. It is only until recently that we begin to understand the molecular mechanisms that underlie the beneficial effects associated with LPL(S447X). This review summarizes the current literature on this interesting LPL variant.

Animals↗