Alirocumab reduces total coronary plaque burden in patients with familial hypercholesterolaemia and no previous clinical atherosclerotic disease

Background

It is well known that statins, ezetimibe and other lipid lowering treatments such as Evolocumab (PCSK9-Inhibitor) reduce cardiovascular events by decreasing LDL-cholesterol (LDL-C) levels and slowing the progression of coronary atherosclerosis. Nevertheless, cardiovascular (CV) risk remains. Alirocumab, a PCSK9 inhibitor has demonstrated a reduction in cardiovascular events but its relationship with coronary atherosclerosis reduction has not been adequately demonstrated.

Purpose

The ARCHITECT trial sought to determine whether Alirocumab 150 mg/2 weeks is able to stop or reverse coronary atherosclerosis progression, by assessing coronary plaque burden (CPB) by serial multidetector computed tomography (MDCT).

Methods

A total of 104 patients with molecularly characterized heterozygous familial hypercholesterolaemia (FH) without clinical cardiovascular disease were enrolled in this trial. Patients had to have CPB >30% as documented by MDCT, be on maximum tolerated statin therapy with or without ezetimibe and LDL-C >100 mg/dL. Patients underwent a MDCT at enrollment and after 18-month treatment with alirocumab and they were analyzed by means of QAngio CT (Medis medical imaging system, the Netherlans). The pre-specified primary endpoint was change in CPB.

Results

Median age was 53.3 (46.2–59.4) years (54, 51.9% woman). Median LDL-cholesterol was 138.9 mg/dL. There was a significant reduction in the primary endpoint as Alirocumab reduced CPB from 34.6 (32.9–36.8)% to 30.4 (27.4–33.4)%. Significant reductions in LDL-C (67%) and atherosclerotic plaque volume were also found. Plaque regression as estimated by CPB was found in 91 (87.5%) patients. Main resuts may be found in figure 1.

Conclusions

Alirocumab demonstrated significant regression of CPB on MDCT over 18 months. ARCHITECT provides crucial mechanistic clues on coronary plaque behavior under the use of Alirocumab and its results could link and explain ODYSSEY-OUTCOMES results.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Sanofi

Persistence to long-term PCSK9 inhibitors treatment and its effectiveness in familial hypercholesterolemia: data from the SAFEHEART study

Background

Most patients with heterozygous familial hypercholesterolemia (FH) do not achieve current LDL-C goals proposed by European guidelines with conventional lipid-lowering therapy (LLT). Chronic use of PCSK9 inhibitors (PCSK9i) have shown to reduce LDL-C levels up to 61% on top of statins. Persistence to chronic LLT is important to reduce the burden of atherosclerotic cardiovascular disease (ASCVD).

Purpose

To analyze persistence and effectiveness of PCSK9i in clinical practice setting in FH patients from the SAFEHEART register with long-term follow-up.

Methods

SAFEHEART is an open, long-term prospective study of a cohort of subjects with molecular diagnosis of FH. Follow-up is carried out every year through a standardized phone-call to collect clinical conditions, persistence to medications, lipid profile, and cardiovascular events. This study analyses subjects ≥18 years of age on stable LLT who have received PCSK9i.

Results

696 individuals (46% females), median age 56.4 years (IQR 49–66) started with PCSK9i (49% alirocumab and 51% evolocumab). Out of them 38% had history of ASCVD, and 89% were on maximum LLT. Median LDL-C at the moment of starting PCSK9i was 145 mg/dL (IQR, 123–177), representing a poor 2016 & 2019 ESC/EAS guidelines achievement (3% and 0.1% respectively). After a median follow-up of 3.7 years (IQR, 2.3–4.8), 669 patients (96%) remained on PCSK9i treatment during entire follow-up. Only 27 patients (4%) discontinued, 5 temporarily (0.7%) and 22 permanently (3.2%). Most common reasons for PCSK9i treatment interruption were medical decision (n=6), adverse event (AE) (n=5), patient decision not related with AE (n=5) and comorbidity (n=5). Median time to permanent discontinuation was 15 months (IQR, 4–33).

Median LDL-C levels observed and % of LDL-C reduction obtained after 1 year of treatment and in the last follow-up visit were: 63 mg/dL (IQR, 43–88), 61 mg/dL (IQR, 44–82), 57.6% (IQR, 39.5–69) and 58% (IQR, 44–68), respectively. 2016 ESC/EAS guidelines LDL-C goals was achieved by 70% of patients at year 1 and 77% in the last follow-up visit after the introduction of PCSK9i (p<0.001). 2019 ESC/EAS goals were achieved by 44.5% and 48% (p=0.1).

Conclusion

Long-term persistence to PCSK9i treatment in FH patients is very high (96%) and reasons for discontinuation are diverse. This study shows that COVID-19 pandemic did not affected persistence to treatment. Effectiveness in LDL-C reduction and LDL-C goal achievement improved significantly with introduction of PCSK9i in clinical practice setting.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): AMGEN

MiR-6821-5p and coronary calcification in familial hypercholesterolemia patients with subclinical atherosclerosis

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Agencia Estatal de Investigaciópn (AEI)” - Spanish Ministry of Economy Competitiveness of Science Agencia Estatal de Investigaciópn (AEI)” - Spanish Institute of Health Carlos III, ISCIII

Background

Familial hypercholesterolemia (FH) is associated with premature atherosclerosis but FH patients have a highly variable risk of clinical atherosclerotic cardiovascular disease (ACVD) presentation. Preclinical atherosclerosis has been identified by imaging of coronary artery calcium (CAC); however, little is known of the molecular pathways involved in vascular calcification in FH. Circulating microRNAs are proven as a powerful epigenetic regulators of atherosclerosis development.

Purpose

We have investigated the circulating microRNA signature of FH patients with CAC and asymptomatic atherosclerosis.

Methods

Differential plasma miRNA profiling was performed by Affymetrix microarray technology (discovery studies) and RT-PCR using TaqMan technology (validation studies) in plasma of FH subjects (N=86) included in a multicentric nationwide cohort. FH-patients with and without coronary calcification (determined by Agatston score) by computed tomographic angiography imaging were investigated. Proof-of-concept validation studies were performed in cell culture of human coronary-derived vascular smooth muscle cells (hcVSMC) calcification analysis.

Results

Using a non-targeted approach, a differential signature of 15 miRNA (all upregulated) was identified in FH-patients presenting subclinical atherosclerosis with calcified plaques (FH-CCS+, N=49, Agatston score >100) compared with FH-subjects without coronary calcification (FH-CCS-, N=37, Agatston score 0). After RT-PCR validation, 3 miRNAs (miR-193a-5p, miR-30e-5p and miR-6821-5p) were significantly upregulated in FH-CCS+ patients. ROC-analysis confirmed miR-6821-5p as the best miRNA for discriminating FH-patients with coronary calcification (AUC 0.70±0.06, P=0.003). High miR-6821-5p levels associated to older age (P=0.003) and high LDL burden (P=0.014), two established risk factors for calcification. In vitro studies showed miR-6821-5p up-regulation (P=0.018) in hcVSMC cultured under calcification conditions (high-phosphate medium) and expressing increased levels of calcification-related genes such as SPP1 (Secreted Phosphoprotein 1, osteopontin) and BMP2 (Bone Morphogenetic Protein 2) when compared with non-calcified hcVSMC.

Conclusion

Up-regulated levels of miR-6821-5p are found in FH patient with CAC+ atherosclerotic plaques, as well as in calcified isolated human coronary smooth muscle cells that express the pro-calcification genes as osteopontin and BMP2. miR-6821-5p is involved in the development of calcification in the coronary arteries and in the development of atherosclerotic plaques.

Nesting preferences of the green sea turtle (Chelonia mydas L.) and the hawksbill sea turtle (Eretmochelys imbricata L.) in the SW of Mahe Island in the Seychelles

Data concerning 212 turtles emerging on the southwest beaches of Mahe Island in the Seychelles were collected in 2017 and 2018. These data were used to model the probability of eggs being laid in relation to several variables. The probability of successful laying after emergence was highest on certain beaches and in areas of short vegetation, between open sand and trees. We found successful laying was related to the physical properties of the soil, indicating that survivability of embryos and hatchlings is higher in certain areas. The turtles appeared to choose zones where soil had low salinity, good drainage but ability to retain water, and absence of spring tides and extreme temperatures.

[The approach to hypercholesterolemia in health strategies and plans in Spain: present situation and future proposals]

BACKGROUND

Cardiovascular Diseases (CVD) are a major cause of death worldwide and Hypercholesterolemia (HC) is an important cardiovascular risk factor. In Spain, approximately 25% of middle-aged adults suffer from HC. Our objective was to analyse current health strategies and plans in Spain related to CVD and HC in order to define possible future courses of action to bring about better control from a health management and policy perspective.

METHODS

The study was observational and descriptive. In the first step, a literature review was carried out, followed by six semi structured interviews. In the second step, a group of 12 experts in the field identified existing barriers to HC control and suggested ways to reduce premature mortality due to CVD.

RESULTS

A total of 51 documents were identified, of which 43% referred to HC. There was a high variability at the regional level in the implementation of measures and initiatives for the control of HC. Barriers that were identified were : trivial-ization of HC, lack of active participation by key stakeholders, lack of understanding of the impact of HC, existing care models and pathways, and short-term health policies that limit the provision of resources for HC care and control.

CONCLUSION

Despite the considerable medical and socioeconomic burden of CVD and HC in Spain, the importance of HC is not reflected in health policies. There is a lack of HC control measures, even when they are shown to be highly feasible and beneficial. This article proposes specific measures to improve control of this issue.

Clinically used selective oestrogen receptor modulators increase LDL receptor activity in primary human lymphocytes

BACKGROUND AND PURPOSE

Treatment with selective oestrogen receptor modulators (SERMs) reduces low-density lipoprotein (LDL) cholesterol levels. We assessed the effect of tamoxifen, raloxifene and toremifene and their combinations with lovastatin on LDL receptor activity in lymphocytes from normolipidaemic and familial hypercholesterolaemic (FH) subjects, and human HepG2 hepatocytes and MOLT-4 lymphoblasts.

EXPERIMENTAL APPROACH

Lymphocytes were isolated from peripheral blood, treated with different compounds, and 1,1'-dioctadecyl-3,3,3,3'-tetramethylindocarbocyanine perchlorate (DiI)-labelled LDL uptake was analysed by flow cytometry.

KEY RESULTS

Tamoxifen, toremifene and raloxifene, in this order, stimulated DiI-LDL uptake by lymphocytes by inhibiting LDL-derived cholesterol trafficking and subsequent down-regulation of LDL receptor expression. Differently to what occurred in HepG2 and MOLT-4 cells, only tamoxifen consistently displayed a potentiating effect with lovastatin in primary lymphocytes. The SERM-mediated increase in LDL receptor activity was not altered by the anti-oestrogen ICI 182,780 nor was it reproduced by 17β-oestradiol. However, the tamoxifen-active metabolite endoxifen was equally effective as tamoxifen. The SERMs produced similar effects on LDL receptor activity in heterozygous FH lymphocytes as in normal lymphocytes, although none of them had a potentiating effect with lovastatin in heterozygous FH lymphocytes. The SERMs had no effect in homozygous FH lymphocytes.

CONCLUSIONS AND IMPLICATIONS

Clinically used SERMs up-regulate LDL receptors in primary human lymphocytes. There is a mild enhancement between SERMs and lovastatin of lymphocyte LDLR activity, the potentiation being greater in HepG2 and MOLT-4 cells. The effect of SERMs is independent of oestrogen receptors but is preserved in the tamoxifen-active metabolite endoxifen. This mechanism may contribute to the cholesterol-lowering action of SERMs.

Validation of a food frequency questionnaire in Spanish patients with familial hypercholesterolaemia

BACKGROUND AND AIMS

The aim of this study is to validate a semi-quantitative Food Frequency Questionnaire (FFQ) used for general population in Spain, in patients with familial hypercholesterolaemia (FH).

SUBJECTS AND METHODS

Subjects with genetic diagnosis of FH were randomly selected from the Spanish FH Registry. They completed an FFQ based in 113 food items at inclusion (FFQ1) and after 1 year (FFQ2), and a 3-day dietary records (DR) every 3 months. Detailed instruction about how to register foods and beverages was given by a trained nutritionist. Each DR and FFQ was systematically coded, and the daily nutrients intake in absolute, percentage and nutrient density terms were estimated using a software system based on food composition tables. Pearson correlation coefficient was calculated with correction-repeated measurements to assess the reproducibility of both FFQ and the four 3-day DRs, as well as the validity of FFQ comparing to the mean of 3 days' DR.

RESULTS

A total of 112 subjects (58 females and 54 males, aged 43 ± 16 years) finished the study. There were no differences between FFQ1, FFQ2 and mean FFQ (FFQa) in mean absolute and percentage values of selected daily nutrients' intake. Comparison between FFQ1, FFQ2, FFQa and the mean of four 3-day DRs was statistically significant in all absolute values, but not in percentage or nutrient density terms. Corrected Pearson correlation coefficient ranged from 0.470 to 0.952 for mean values of all nutrients, except alcohol.

CONCLUSION

This study demonstrated that FFQ is a reliable tool to assess the dietary pattern in FH patients.

Polymorphism at the TRIB1 gene modulates plasma lipid levels: insight from the Spanish familial hypercholesterolemia cohort study

BACKGROUND AND AIMS

rs17321515 SNP has been associated with variation in LDL-C, high density lipoprotein cholesterol and triglycerides concentrations. This effect has never been studied in patients with severe hypercholesterolemia. Therefore, our aims were to assess the association of the rs17321515 (TRIB1) SNP with plasma lipids concentrations and anthropometric variables and to explore the interaction between this SNP and some classic risk factors in patients with familial hypercholesterolemia (FH).

METHODS AND RESULTS

rs17321515 SNP was genotyped in 531 subjects with genetic diagnosis of FH. Homozygous A/A had significantly higher waist circumference compared with G/G subjects (P = 0.006) and carriers of the minor allele G (P = 0.039). Interestingly, smokers homozygous for the A allele displayed higher plasma triglycerides concentrations (P = 0.029), higher VLDL-C levels (P = 0.023) and higher TC/HDL-C ratio (P = 0.035) than carriers of the minor allele G. In addition, homozygous A/A with the presence of arcus cornealis displayed lower plasma ApoA-I levels (P = 0.024) and higher TC/HDL-C ratio (P = 0.046) than carriers of the minor allele G.

CONCLUSIONS

Smoking status and presence of arcus cornealis modulate the effect of rs17321515 (TRIB1) polymorphism on plasma lipids levels in patients with FH. These results could explain the differences in the susceptibility to coronary heart disease in these patients.

Airways changes related to air pollution exposure in wheezing children

In this study, we aimed to evaluate the relationship between individual total exposure to air pollution and airway changes in a group of 51 wheezing children. Respiratory status was assessed four times (January 2006, June 2006, January 2007 and June 2007) during a 1-week period through a standardised questionnaire, spirometry, exhaled nitric oxide fraction and pH in exhaled breath condensate (EBC). Concentrations of particles with a 50% cut-off aerodynamic diameter of 10 µm (PM(10)), O(3), NO(2) and volatile organic compounds were estimated through direct measurements with an ad hoc device or air pollution modelling in the children's schools and at their homes in the same 4 weeks of the study. For each child, total exposure to the different air pollutants was estimated as a function of pollutant concentrations and daily activity patterns. Increasing total exposure to PM(10), NO(2), benzene, toluene and ethylbenzene was significantly associated with a decrease of forced expiratory volume in 1 s (FEV(1)) and with an increase of change in FEV(1). Increasing exposure to NO(2) and benzene was also related to a significant decrease of FEV(1)/forced vital capacity. Increasing exposure to PM(10), NO(2), benzene and ethylbenzene was associated with acidity of EBC. This study suggests an association in wheezing children between airway changes and total exposure to air pollutants, as estimated by taking into account the concentration in the various microenvironments attended by the children.

Olive oil and health: summary of the II international conference on olive oil and health consensus report, Jaén and Córdoba (Spain) 2008

Olive oil (OO) is the most representative food of the traditional Mediterranean Diet (MedDiet). Increasing evidence suggests that monounsaturated fatty acids (MUFA) as a nutrient, OO as a food, and the MedDiet as a food pattern are associated with a decreased risk of cardiovascular disease, obesity, metabolic syndrome, type 2 diabetes and hypertension. A MedDiet rich in OO and OO per se has been shown to improve cardiovascular risk factors, such as lipid profiles, blood pressure, postprandial hyperlipidemia, endothelial dysfunction, oxidative stress, and antithrombotic profiles. Some of these beneficial effects can be attributed to the OO minor components. Therefore, the definition of the MedDiet should include OO. Phenolic compounds in OO have shown antioxidant and anti-inflammatory properties, prevent lipoperoxidation, induce favorable changes of lipid profile, improve endothelial function, and disclose antithrombotic properties. Observational studies from Mediterranean cohorts have suggested that dietary MUFA may be protective against age-related cognitive decline and Alzheimer's disease. Recent studies consistently support the concept that the OO-rich MedDiet is compatible with healthier aging and increased longevity. In countries where the population adheres to the MedDiet, such as Spain, Greece and Italy, and OO is the principal source of fat, rates of cancer incidence are lower than in northern European countries. Experimental and human cellular studies have provided new evidence on the potential protective effect of OO on cancer. Furthermore, results of case-control and cohort studies suggest that MUFA intake including OO is associated with a reduction in cancer risk (mainly breast, colorectal and prostate cancers).

[Worsening of migraine symptoms due to giant pineal cyst apoplexy]

INTRODUCTION

Although the association between headaches and pineal gland cysts has been suggested on a number of occasions, no precise evidence of exactly what this relation involves has been produced to date. It is known, however, that a cyst in the pineal gland can bring on or worsen headaches, especially if it is large or there has been bleeding, due to obstructive compromise in the third ventricle and the resulting hydrocephalus that is produced.

CASE REPORT

A 15 years-old male who had suffered from migraine from the age of 6 years and who suddenly experienced a worsening of his headaches, both as regards their frequency and their intensity, over the previous days; no known precipitating factor appeared to be involved. Magnetic resonance imaging of the brain revealed the presence of a giant cyst in the pineal gland, with a notable amount of blood inside it, which was producing an obstructive hydrocephalus. The decision was made to resort to surgical treatment, with resection of the cyst and placement of a shunt valve. As a result the patient's headaches improved greatly and this improvement continued throughout a six-month follow-up.

CONCLUSIONS

Worsening of a headache, in this case migraine, for no apparent cause must make us consider secondary processes, although they may be as rare as the one described here.

Electrical conductivity measurement: a new technique to detect iatrogenic initial pedicle perforation

Pedicle screw fixation has achieved significant popularity amongst spinal surgeons for both single and multi-level spinal fusion. Misplacement and pedicle cortical violation occurs in over 20% of screw placement and can result in potential complications such as dysthesia, paraparesis or paraplegia. There have been many advances in techniques available for navigating through the pedicle; however, these techniques are not without drawbacks. A new electrical conductivity-measuring device, previously evaluated on the porcine model to detect the pedicle violation, was evaluated amongst nine European Hospitals to be used in conjunction with the methods currently used in that centre. This new device is based on two original principles; the device is integrated in the drilling or screwing tool. The technology allows real-time detection of perforation through two independent parameters, impedance variation and evoked muscle contractions. Data was collected twofold. Initially, the surgeon was given the device and a comparison was made between the devices ability to detect a breech and the surgeon's ability to detect one using his traditional methods of pedicle preparation. In the second module of the study, the surgeon was limited to using the electrical conductivity detection device as their sole guide to detect pedicle breaches. A comparison was made between the detection ability of the device and the other detection possibilities. Post-operative fine cut CT scanning was used to detect the pedicle breaches. Overall, the 11 trial surgeons performed a total of 521 pedicle drillings on 97 patients. Initially there were 147 drillings with 23 breaches detected. The detection rate of these breaches were 22/23 for the device compared to 10/23 by the surgeon. Over both parts of the study 64 breaches (12.3%) were confirmed on post-operative CT imaging. The electrical conductivity detection device detected 63 of the 64 breaches (98.4%). There was one false negative and four false positives. This gives the device an overall sensitivity of 98% and specificity of 99% for detecting a pedicle breach. The negative predictive value was 99.8%, with a positive predictive value of 94%. No adverse event was noted with the use of the electrical conductivity device. Electrical conductivity monitoring may provide a simple, safe and sensitive method of detecting pedicle breech during routine perforation of the pedicle, in the course of pedicle screw placement.

[Aneurysmal bone cyst of the sphenoid sinus]

Aneurysmal bone cyst is an uncommon lesion that occurs mainly in long bones and vertebrae, being the location in the sphenoid sinus extremely rare. Its origin is unknown, but it can be considered as a vascular phenomenon secondary to a primary lesion. Other primary diseases that may be associated to aneurysmal bone cyst are polyostotic fibrous dysplasia and giant-cell tumors. We report the case of a patient with an aneurysmal bone cyst in the sphenoid sinus causing vision dysfunction.

International conference on the healthy effect of virgin olive oil

1. Ageing represents a great concern in developed countries because the number of people involved and the pathologies related with it, like atherosclerosis, morbus Parkinson, Alzheimer's disease, vascular dementia, cognitive decline, diabetes and cancer. 2. Epidemiological studies suggest that a Mediterranean diet (which is rich in virgin olive oil) decreases the risk of cardiovascular disease. 3. The Mediterranean diet, rich in virgin olive oil, improves the major risk factors for cardiovascular disease, such as the lipoprotein profile, blood pressure, glucose metabolism and antithrombotic profile. Endothelial function, inflammation and oxidative stress are also positively modulated. Some of these effects are attributed to minor components of virgin olive oil. Therefore, the definition of the Mediterranean diet should include virgin olive oil. 4. Different observational studies conducted in humans have shown that the intake of monounsaturated fat may be protective against age-related cognitive decline and Alzheimer's disease. 5. Microconstituents from virgin olive oil are bioavailable in humans and have shown antioxidant properties and capacity to improve endothelial function. Furthermore they are also able to modify the haemostasis, showing antithrombotic properties. 6. In countries where the populations fulfilled a typical Mediterranean diet, such as Spain, Greece and Italy, where virgin olive oil is the principal source of fat, cancer incidence rates are lower than in northern European countries. 7. The protective effect of virgin olive oil can be most important in the first decades of life, which suggests that the dietetic benefit of virgin olive oil intake should be initiated before puberty, and maintained through life. 8. The more recent studies consistently support that the Mediterranean diet, based in virgin olive oil, is compatible with a healthier ageing and increased longevity. However, despite the significant advances of the recent years, the final proof about the specific mechanisms and contributing role of the different components of virgin olive oil to its beneficial effects requires further investigations.

Experimental and interventional dietary study in humans on the role of HDL fatty acid composition in PGI2 release and Cox-2 expression by VSMC

BACKGROUND

High-density lipoproteins (HDLs) induce prostacyclin (PGI2) release in vascular smooth muscle cells (VSMCs) by up-regulation of cyclooxygenase-2 (Cox-2). Our goal was to analyze the role of human HDL lipid moiety on Cox-2-dependent PGI2 synthesis in human VSMCs and to assess the impact that the intake of diets with different fatty acid composition exert on HDL-induced PGI2 release.

MATERIALS AND METHODS

Human VSMCs were treated with HDL or fatty acids in the presence or absence of different cell signalling inhibitors and PGI2 (by enzyme immunoassay) and Cox-2 protein levels (by Western blot) were analyzed. High-density lipoproteins were obtained from a plasma pool or from plasma of 12 volunteers subjected to a longitudinal dietary interventional study of three consecutive diets periods enriched in monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids n-6 (PUFA n-6) or n-3 (PUFA n-3).

RESULTS

High-density lipoprotein delipidation attenuated the effect of HDL on both PGI2 synthesis and Cox-2 up-regulation, while arachidonic acid (AA) but not other fatty acids mimicked the effects of HDL. Arachidonic acid induced PGI2 synthesis and Cox-2 expression through similar mechanisms to those activated by HDL [pertussis toxin-sensitive G proteins, p42/44 mitogen-activated protein kinase (MAPK), p38MAPK, and c-Jun N-terminal kinase-1 (JNK-1) pathways]. Finally, we observed that HDL from the PUFA n-3 dietary period induced lower PGI2 release than that from the PUFA n-6 period (64% vs. 100%).

CONCLUSIONS

Our results suggest that lipid moiety modulates HDL-induced PGI2 release/Cox-2 up-regulation in human VSMCs, and that changes in fatty acids as accomplished with the diet can modulate vascular PGI2 homeostasis.

Apolipoprotein E genotype is not associated with cardiovascular disease in heterozygous subjects with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) is a genetic disorder characterized by high low-density lipoprotein cholesterol levels and premature cardiovascular disease (CVD). There are important differences in the presence of CVD among heterozygous subjects with FH. Some of this variability can be explained by genetic factors, and the apolipoprotein (apo) E genotype has been proposed as a useful marker.

METHODS

We analyzed the apo E genotype in 706 non-related subjects who were heterozygous for FH from Spain. CVD was present in 198 subjects (28%), 132 men (41%) and 66 women (17%).

RESULTS

Apo E allele frequencies for the epsilon 3, epsilon 4, and epsilon 2 alleles were 0.89, 0.09, and 0.02 respectively. Age, body mass index, smoking status, high blood pressure, diabetes mellitus, presence of tendon xanthomas, total cholesterol level, triglyceride levels, high-density lipoprotein cholesterol level, low-density lipoprotein cholesterol level, and Lp(a) did not differ among genotypes. The incidence of CVD and the age of onset of CVD did not differ among genotypes either. In the multivariant analysis, apo E genotype did not contribute significantly to CVD.

CONCLUSIONS

Heterozygous men with FH have a very high risk of coronary disease in a Mediterranean country, and the apo E genotype in this large group of adults with FH is not associated either with CVD or lipid values, in contrast with the established effect in the general population.

A common variant in the ABCA1 gene is associated with a lower risk for premature coronary heart disease in familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is a common autosomal codominant hereditary disease caused by defects in the LDL receptor (LDLR) gene, and one of the most common characteristics of affected subjects is premature coronary heart disease (CHD). In heterozygous FH patients, the clinical expression of FH is highly variable in terms of the severity of hypercholesterolaemia and the age of onset and severity of CHD. Identification of mutations in the ATP binding cassette transporter 1 (ABCA1) gene in patients with Tangier disease, who exhibit reduced HDL cholesterol and apolipoprotein A1 concentrations and premature coronary atherosclerosis, has led us to hypothesise that ABCA1 could play a key role in the onset of premature CHD in FH. In order to know if the presence of the R219K variant in the ABCA1 gene could be a protective factor for premature CHD in FH, we have determined the presence of this genetic variant by amplification by PCR and restriction analysis in a group of 374 FH subjects, with and without premature CHD. The K allele of the R219K variant was significantly more frequent in FH subjects without premature CHD (0.32, 95% CI 0.27 to 0.37) than in FH subjects with premature CHD (0.25, 95% CI 0.21 to 0.29) (p<0.05), suggesting that the genetic variant R219K in ABCA1 could influence the development and progression of atherosclerosis in FH subjects. Moreover, the K allele of the R219K polymorphism seems to modify CHD risk without important modification of plasma HDL-C levels, and it appears to be more protective for smokers than non-smokers.

A double mutant [N543H+2393del9] allele in the LDL receptor gene in familial hypercholesterolemia: effect on plasma cholesterol levels and cardiovascular disease

Familial hypercholesterolemia is a genetic disorder caused by mutations in the LDL receptor gene. During a survey of mutations of LDL receptor gene in Spanish FH patients we found two mutations in the same allele: a missense N543H mutation in exon 11 and a 9bp inframe deletion (2393del9) located in exon 17. This double mutant allele was founded in 10 out of 458 unrelated patients: one homozygous FH [N543H+2393del9] + [N543H+2393del9], one compound heterozygote [N543H+2393del9] + [W-18X+E256K] and 8 heterozygotes. Flow cytometric analysis showed a defective LDL binding (20% of normal value) and internalization (23%) in lymphocytes from the homozygous patient; furthermore, studies of mitogen-stimulated lymphocytes demonstrated that the ability of LDL to support cell proliferation was impaired. Unexpectedly, not all carriers of the double mutant allele develop hypercholesterolemia and, furthermore, cholesterol-lowering treatment of the homozygous patient resulted in a 58% LDL cholesterol reduction. In conclusion, the phenotypic expression in the homozygous and heterozygous patients presented here, as well as the LDL-receptor residual activity, allowed the classification of this mutation as mild extending the group of mild mutations found at homozygosity.

Sustained long-term improvement of arterial endothelial function in heterozygous familial hypercholesterolemia patients treated with simvastatin

Patients with heterozygous familial hypercholesterolemia (hFH) are at very high risk for premature coronary heart disease. In the last decade, treatment with statins has reduced cardiovascular mortality in these patients. The aim of this study was to analyze arterial endothelial function assessed as flow-mediated dilatation (FMD) and soluble E-selectin (sE-selectin) levels in patients with hFH under a long-term lipid-lowering treatment. Twenty-five patients who completed the study received a dose of simvastatin to achieve a treatment goal of at least 30% reduction in serum low-density lipoprotein (LDL)-cholesterol (LDL-C) for 52 weeks. Functional and biochemical measurements were taken at entry, and at week 12 and 52 of treatment. FMD was measured by vascular ultrasound of the brachial artery. sE-selectin, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 were determined by enzyme linked immunosorbent assay (ELISA). LDL-C levels were significantly reduced by treatment at week 12 and maintained at week 52 (reduction vs. baseline, 44+/-12 and 43+/-11%, respectively, P<0.0001). A significant improvement in endothelial function, measured as FMD (baseline, 4.7+/-6.2%; 12 weeks, 12.3+/-5.9%; 52 weeks, 9.7+/-4.7%; P<0.005) and a reduction in sE-selectin levels (baseline, 16.2+/-3.4 ng/ml; 12 weeks, 11.0+/-3.2 ng/ml; 52 weeks, 12.3+/-4.2 ng/ml; P<0.01) were observed. Endothelial-independent relaxation induced by nitroglycerin was not modified during the study. Our results indicate that a long-term treatment with simvastatin produced a sustained beneficial effect in endothelial function in hFH patients.

Atmospheric baseline levels of PCDD and PCDF in the region of Oporto

An external monitoring plan (EMP) is being implemented in the region of Oporto, Portugal, to follow the potential effects of a future incinerator of municipal solid waste. Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) were measured during 1998 and the first semester of 1999, prior to the working up of the incineration unit. The baseline levels obtained through this intensive monitoring work are presented and discussed in the present paper.