Impact of PCSK9 inhibitors in glycaemic control and new-onset diabetes.

BACKGROUND: The diabetogenic effect of statins has been well established by clinical trials, Mendelian randomisation studies and meta-analyses. According to large clinical trials, PCSK9 inhibitors (PCSK9i) have no deleterious impact on glucose metabolism. However, few real-life studies have yet evaluated the long-term effects of these drugs on glucose homeostasis and their impact on new-onset diabetes (NODM). METHODS: We studied 218 patients treated with either alirocumab or evolocumab (70% with familial hypercholesterolemia) for at least three years (PCSK9iG). We studied the NODM rate in the nondiabetic group at baseline (168) and overall glucose metabolism control in the whole group. Incidental DM was compared with two groups. The first was a propensity score matching (PSM)-selected group (n = 168) from the database of patients attending the Reus lipid unit (Metbank, n = 745) who were not on PCSK9i (PSMG). The second was a subgroup with a similar age range (n = 563) of the Di@bet.es study (Spanish prospective study on diabetes development n = 5072) (D@G). The incidence was reported as the percentage of NODM cases per year. RESULTS: The fasting glucose (FG) level of the subjects with normoglycaemia at baseline increased from 91 (86-95.5) to 93 (87-101) mg/dL (p = 0.014). There were 14 NODM cases in the PCSK9i group (2.6%/y), all among people with prediabetes at baseline. The incidence of NODM in PSMG and D@G was 1.8%/y (p = 0.69 compared with the PCSK9iG). The incidence among the subjects with prediabetes was 5.1%/y in the PCSK9iG, 4.8%/y in the PSMG and 3.9%/y in the D@G (p = 0.922 and p = 0.682, respectively). In the multivariate analysis, only the FG level was associated with the development of NODM in the PCSK9iG (OR 1.1; 95% CI: 1.0-1.3; p = 0.027). Neither FG nor A1c levels changed significantly in patients with DM at baseline. CONCLUSION: A nonsignificant increase in NODM occurred in the PCSK9iG, particularly in patients with prediabetes, compared with the PSMG and D@G groups. Baseline FG levels were the main variable associated with the development of DM. In the subjects who had DM at baseline, glucose control did not change. The impact of PCSK9i on glucose metabolism should not be of concern when prescribing these therapies.

Age, Origin and Functional Study of the Prevalent LDLR Mutation Causing Familial Hypercholesterolaemia in Gran Canaria.

The p.(Tyr400_Phe402del) mutation in the LDL receptor (LDLR) gene is the most frequent cause of familial hypercholesterolaemia (FH) in Gran Canaria. The aim of this study was to determine the age and origin of this prevalent founder mutation and to explore its functional consequences. For this purpose, we obtained the haplotypic information of 14 microsatellite loci surrounding the mutation in one homozygous individual and 11 unrelated heterozygous family trios. Eight different mutation carrier haplotypes were identified, which were estimated to originate from a common ancestral haplotype 387 (110-1572) years ago. This estimation suggests that this mutation happened after the Spanish colonisation of the Canary Islands, which took place during the fifteenth century. Comprehensive functional studies of this mutation showed that the expressed LDL receptor was retained in the endoplasmic reticulum, preventing its migration to the cell surface, thus allowing us to classify this LDLR mutation as a class 2a, defective, pathogenic variant.

Estrategias de tratamiento de las dislipemias en prevención primaria y secundaria. Registro de la Sociedad Española de Arteriosclerosis / Dyslipidemia treatment strategies in primary and secondary prevention. Dyslipemia Registry of the Spanish Arteriosclerosis Society

Introducción: Los estudios clínicos reflejan que los pacientes con riesgo cardiovascular elevado todavía están lejos de alcanzar los objetivos terapéuticos, especialmente de los niveles de cLDL. Si el manejo de estos pacientes en unidades especializadas difiere de otros escenarios no es conocido. Pacientes y métodos: Se seleccionaron 61 Unidades de Lípidos certificadas en el Registro de Dislipemias de la Sociedad Española de Arteriosclerosis para la recogida de datos del estudio. Se incluyeron 3.58 sujetos > 18 años que cumplían los criterios de hipercolesterolemia (colesterol LDL ≥ 160 mg/dL o colesterol no HDL ≥ 190 mg/dL) sin hipercolesterolemia familiar. Un total de 1.665 sujetos fueron estudiados con un tiempo medio de seguimiento de 4,2 años. Resultados y conclusiones: Un total de 42 sujetos tuvieron un evento cardiovascular desde su inclusión en el Registro, que supone 0,6%. No hubo diferencias en el tratamiento utilizado al inicio del seguimiento entre los sujetos con y sin evento prospectivo. El cLDL mejoró durante el seguimiento, pero 50% de los pacientes no alcanzaron los objetivos terapéuticos en la visita final del seguimiento. Se observó un aumento del uso de tratamiento hipolipemiante de alta potencia, incluyendo los inhibidores de PCSK9 en un 16,7% de los sujetos con recurrencias.(AU)

Introduction: Clinical studies show that patients with high cardiovascular risk are still far from reaching the therapeutic objectives, especially of the levels of LDL cholesterol. If the management of these patients in specialized units differs from other scenarios is known. Patients and methods: 61 certified Lipid Units were selected in the Registry of Dyslipemias of the Spanish Arteriosclerosis Society for the collection of study data. The study included 3958 subjects >18 years of age who met the criteria for hypercholesterolemia (LDL cholesterol ≥160 mg/dL or non-HDL cholesterol ≥190 mg/dL) without familial hypercholesterolemia. A total 1,665 subjects were studied with a mean follow-up time of 4.2 years. Results and conclusions: A total of 42 subjects had a cardiovascular event since their inclusion in the Registry, which represents 0.6%. There were no differences in the treatment used at follow-up, but 50% of the patients did not reach the therapeutic goals at the visit end of follow-up. An increase in the potency of the lipid-lowering treatment was observed, including PCSK9 inhibitors use in 16.7% of subjects with recurrences.(AU)

Dyslipidemia treatment strategies in primary and secondary prevention. Dyslipemia Registry of the Spanish Arteriosclerosis Society. / Estrategias de tratamiento de las dislipemias en prevención primaria y secundaria. Registro de la Sociedad Española de Arteriosclerosis.

INTRODUCTION: Clinical studies show that patients with high cardiovascular risk are still far from reaching the therapeutic objectives, especially of the levels of LDL cholesterol. If the management of these patients in specialized units differs from other scenarios is known. PATIENTS AND METHODS: 61 certified Lipid Units were selected in the Registry of Dyslipemias of the Spanish Arteriosclerosis Society for the collection of study data. The study included 3958 subjects >18 years of age who met the criteria for hypercholesterolemia (LDL cholesterol ≥160 mg/dL or non-HDL cholesterol ≥190 mg/dL) without familial hypercholesterolemia. A total 1,665 subjects were studied with a mean follow-up time of 4.2 years. RESULTS AND CONCLUSIONS: A total of 42 subjects had a cardiovascular event since their inclusion in the Registry, which represents 0.6%. There were no differences in the treatment used at follow-up, but 50% of the patients did not reach the therapeutic goals at the visit end of follow-up. An increase in the potency of the lipid-lowering treatment was observed, including PCSK9 inhibitors use in 16.7% of subjects with recurrences.

Leu22_Leu23 Duplication at the Signal Peptide of PCSK9 Promotes Intracellular Degradation of LDLr and Autosomal Dominant Hypercholesterolemia.

BACKGROUND: PCSK9 (Proprotein convertase subtilisin/kexin type 9) regulates LDL-C (low-density lipoprotein cholesterol) metabolism by targeting LDLr (LDL receptor) for lysosomal degradation. PCSK9 gain-of-function variants cause autosomal dominant hypercholesterolemia by reducing LDLr levels, the D374Y variant being the most severe, while loss-of-function variants are associated with low LDL-C levels. Gain-of-function and loss-of-function activities have also been attributed to variants occurring in the PCSK9 signal peptide. Among them, L11 is a very rare PCSK9 variant that seems to increase LDL-C values in a moderate way causing mild hypercholesterolemia. METHODS: Using molecular biology and biophysics methodologies, activities of L8 and L11 variants, both located in the leucine repetition stretch of the signal peptide, have been extensively characterized in vitro. RESULTS: L8 variant is not associated with increased LDLr activity, whereas L11 activity is increased by ≈20% compared with wt PCSK9. The results suggest that the L11 variant reduces LDLr levels intracellularly by a process resulting from impaired cleavage of the signal peptide. This would lead to less efficient LDLr transport to the cell membrane and promote LDLr intracellular degradation. CONCLUSIONS: Deletion of a leucine in the signal peptide in L8 variant does not affect PCSK9 activity, whereas the leucine duplication in the L11 variant enhances LDLr intracellular degradation. These findings highlight the importance of deep in vitro characterization of PCSK9 genetic variants to determine pathogenicity and improve clinical diagnosis and therapy of inherited familial hypercholesterolemia disease.

Hipercolesterolemia familiar en Gran Canaria: mutación con efecto fundador y alta frecuencia de diabetes / Familial hypercholesterolemia in Gran Canaria: Founder mutation effect and high frequency of diabetes

Introducción: Gran Canaria es una región de aislamiento genético para hipercolesterolemia familiar, debido a una mutación fundadora, p.[Tyr400_Phe402del], en el gen del receptor de LDL (LDLR). Datos iniciales indican que sus portadores podrían tener una alta prevalencia de diabetes. Material y métodos: Se reclutó a los pacientes mayores de 30 años con hipercolesterolemia familiar y mutación confirmada en LDLR en un hospital de tercer nivel de Gran Canaria y se comparó la prevalencia de diabetes y otros datos clínicos entre los portadores de p.[Tyr400_Phe402del] y los de otras mutaciones en LDLR. Resultados: El 76,4% de los 89 participantes era portador de p.[Tyr400_Phe402del]. En ese grupo la prevalencia de diabetes fue significativamente más alta (25 vs. 4%, p=0,045). Dichos casos también tenían mayor prevalencia de enfermedad cardiovascular y niveles más altos de colesterol LDL y triglicéridos. No hubo diferencias en edad, peso, índice de masa corporal, cintura, edad de inicio y tiempo de tratamiento con estatinas. Sin embargo, sí precisaban más a menudo inhibidores de PCSK9 (51,5 vs. 24%, p=0,027). Conclusiones: La mutación p.[Tyr400_Phe402del] se asocia a una elevada prevalencia de diabetes, no explicada por factores de riesgo clásicos, como la edad, la obesidad o el uso prolongado de estatinas.(AU)

Introduction: Gran Canaria is a region of genetic isolation of familial hypercholesterolemia due to a founder mutation, p. [Tyr400_Phe402del], in the LDL receptor (LDLR) gene. Initial data suggest that its carriers could have a high prevalence of diabetes. Material and methods: Patients over 30 years of age with familial hypercholesterolemia and a confirmed mutation in LDLR were recruited from a tertiary hospital in Gran Canaria. The prevalence of diabetes and other clinical data were compared among carriers of p. [Tyr400_Phe402del] and those with other LDLR mutations. Results: 76.4% of the 89 participants were carriers of p.[Tyr400_Phe402del]. The prevalence of diabetes in this group was significantly higher (25 vs. 4%, P=.045). These cases also had a higher prevalence of cardiovascular disease and higher levels of LDL cholesterol and triglycerides. There were no differences in age, weight, body mass index, waist, age of onset, and time of statin treatment. However, they required PCSK9 inhibitors more often (51.5 vs 24%, P=.027). Conclusions: The mutation p.[Tyr400_Phe402del] is associated with a high prevalence of diabetes, not explained by classic risk factors, such as age, obesity, or long-term use of statins.(AU)

Cataract Surgery in Elderly Subjects with Heterozygous Familial Hypercholesterolemia in Prolonged Treatment with Statins.

BACKGROUND: Cataracts are the main cause of blindness and represent one fifth of visual problems worldwide. It is still unknown whether prolonged statin treatment favors the development of cataracts. We aimed to ascertain the prevalence of cataract surgery in elderly subjects with genetically diagnosed heterozygous familial hypercholesterolemia (HeFH) receiving statin treatment for ≥5 years, and compare this with controls. METHODS: This is an observational, multicenter, case-control study from five lipid clinics in Spain. We collected data with the following inclusion criteria: age ≥65 years, LDL cholesterol levels ≥220 mg/dL without lipid-lowering drugs, a pathogenic mutation in a candidate gene for HeFH (LDLR, APOB, or PCSK9) and statin treatment for ≥5 years. Controls were selected from relatives of HeFH patients without hypercholesterolemia. Linear and logistic regressions based on generalized linear models and generalized estimating equations (GEE) were used. Cataract surgery was used as a proxy for cataract development. RESULTS: We analyzed 205 subjects, 112 HeFH, and 93 controls, with a mean age of 71.8 (6.5) and 70.0 (7.3) years, respectively. HeFH subjects presented no difference in clinical characteristics, including smoking, hypertension, and type 2 diabetes mellitus, compared with controls. The mean duration of lipid-lowering treatment in HeFH was 22.5 (8.7) years. Cataract surgery prevalence was not significantly different between cases and controls. The presence of cataracts was associated neither with LDLc nor with the length of the statin therapy. CONCLUSION: In the present study, HeFH was not a risk factor for cataract surgery and prolonged statin treatment did not favor it either. These findings suggest that statin treatment is not related with cataracts.

Familial hypercholesterolemia in Gran Canaria: Founder mutation effect and high frequency of diabetes. / Hipercolesterolemia familiar en Gran Canaria: mutación con efecto fundador y alta frecuencia de diabetes.

INTRODUCTION: Gran Canaria is a region of genetic isolation of familial hypercholesterolemia due to a founder mutation, p. [Tyr400_Phe402del], in the LDL receptor (LDLR) gene. Initial data suggest that its carriers could have a high prevalence of diabetes. MATERIAL AND METHODS: Patients over 30 years of age with familial hypercholesterolemia and a confirmed mutation in LDLR were recruited from a tertiary hospital in Gran Canaria. The prevalence of diabetes and other clinical data were compared among carriers of p. [Tyr400_Phe402del] and those with other LDLR mutations. RESULTS: 76.4% of the 89 participants were carriers of p.[Tyr400_Phe402del]. The prevalence of diabetes in this group was significantly higher (25 vs. 4%, P=.045). These cases also had a higher prevalence of cardiovascular disease and higher levels of LDL cholesterol and triglycerides. There were no differences in age, weight, body mass index, waist, age of onset, and time of statin treatment. However, they required PCSK9 inhibitors more often (51.5 vs 24%, P=.027). CONCLUSIONS: The mutation p.[Tyr400_Phe402del] is associated with a high prevalence of diabetes, not explained by classic risk factors, such as age, obesity, or long-term use of statins.

Maternally inherited hypercholesterolemia does not modify the cardiovascular phenotype in familial hypercholesterolemia.

BACKGROUND AND AIMS: Familial hypercholesterolemia (FH) is a codominant autosomal disease characterized by a high risk of cardiovascular disease when not in lipid-lowering treatment. However, there is a large variability in the clinical presentation in heterozygous subjects (HeFH). Maternal hypercholesterolemia has been proposed as a cardiometabolic risk factor later in life. Whether this phenotype variability depends on the mother or father origin of hypercholesterolemia is unknown. The objective of this study was to analyze potential differences in anthropometry, superficial lipid deposits, comorbidities, and lipid concentrations depending on the parental origin of hypercholesterolemia within a large group of HeFH. METHODS: This is a cross-sectional observational, multicenter, nation-wide study in Spain. We recruited adults with HeFH to study clinical differences according to the parental origin. Data on HeFH patients were obtained from the Dyslipidemia Registry of the Spanish Atherosclerosis Society. RESULTS: HeFH patients were grouped in 1231 HeFH-mother-offspring aged 45.7 (16.3) years and 1174 HeFH-father-offspring aged 44.8 (16.7) years. We did not find any difference in lipid parameters (total cholesterol, triglycerides, LDLc, HDLc, and Lp(a)), nor in the comorbidities studied (cardiovascular disease prevalence, age of onset of cardiovascular disease, obesity, diabetes, and hypertension) between groups. Lipid-lowering treatment did not differ between groups. The prevalence of comorbidities did not show differences when they were studied by age groups. CONCLUSIONS: Our research with a large group of subjects with HeFH shows that a potential maternal effect is not relevant in FH. However, due to the size of our sample, potential differences between genders cannot be completely ruled out. This implies that severe maternal hypercholesterolemia during pregnancy is not associated with additional risk in the FH affected offspring.

Diferencias clínicas y genéticas de los pacientes con hipercolesterolemia familiar heterocigota con y sin diabetes mellitus tipo 2 / Clinical and genetic differences between heterozygous familial hypercholesterolemia patients with and without type 2 diabetes

INTRODUCCIÓN Y OBJETIVOS: La menor prevalencia de diabetes mellitus tipo 2 (DM2) en pacientes con hipercolesterolemia familiar heterocigota (HFHe) podría explicar por qué la DM2 no siempre se ha descrito como un predictor de enfermedad cardiovascular (ECV) en estos pacientes. El objetivo del presente estudio fue evaluar los aspectos clínicos y genéticos de pacientes con HFHe y DM2 del registro de dislipidemias de la Sociedad Española de Arteriosclerosis. MÉTODOS: Los pacientes con HFHe se clasificaron según la presencia/ausencia de DM2. Se compararon las características clínicas, bioquímicas y genéticas de ambos grupos. RESULTADOS: De los 2.301 casos de hipercolesterolemia primaria del registro, se incluyeron 1.724 casos con el diagnóstico cierto o probable según la Dutch Lipid Clinic Network para la hipercolesterolemia familiar. Los pacientes con HFHe y DM2 presentaron una tasa más elevada de ECV y un perfil lipídico menos favorable, con niveles más elevados de colesterol total (366,9±86,7 mg/dl frente a 342,0±74,7 mg/dl; diferencia media 24,894; IC95%, 5,840-43,949) y colesterol no-unido a lipoproteínas de alta densidad (316,9±87,8 mg/dl frente a 286,4±75,4 mg/dl; diferencia media 30,500; IC95%, 11,211-49,790). No se encontraron diferencias significativas entre los grupos con respecto al tipo de mutación (p = 0,720). Después de ajustar por los principales factores de riesgo, el análisis de regresión logística confirmó una relación entre la DM2 y la ECV (OR=2,01; IC95%, 1,18-3,43; p = 0,010). CONCLUSIONES: Los pacientes con HFHe y DM2 presentan una tasa más elevada de ECV y un perfil lipídico menos favorable, independientemente del tipo de mutación. La diabetes mellitus es un factor asociado a la presencia de ECV en estos pacientes

INTRODUCTION AND OBJECTIVES: The lower prevalence of type 2 diabetes mellitus (T2DM) in patients with heterozygous familial hypercholesterolemia (HeFH) could explain why T2DM has not always been identified as an independent predictor of cardiovascular disease (CVD) in different familial hypercholesterolemia cohort studies. The aim of the present study was to evaluate clinical and genetic aspects of HeFH patients with T2DM in the dyslipidemia registry of the Spanish Arteriosclerosis Society. METHODS: HeFH patients were classified according to the presence or absence of T2DM. The clinical, biochemical and genetic characteristics of the 2 groups were compared. RESULTS: Of the 2301 patients with primary hypercholesterolemia included in the registry, 1724 with a probable or definite diagnosis according to the Dutch Lipid Clinic Network score were finally included. HeFH patients with T2DM had a higher rate of CVD and a less favorable lipid profile, with higher total cholesterol (366.9±86.7mg/dL vs 342.0±74.7mg/dL; mean difference 24.894; 95%CI, 5.840-43.949) and non-high-density lipoprotein cholesterol (316.9±87.8mg/dL vs 286.4±75.4mg/dL; mean difference 30.500; 95%CI, 11.211-49.790) levels. No significant differences were found between the groups concerning the specific type of HeFH-causing mutation (P=.720). After adjustment for major risk factors, logistic regression analysis confirmed a relationship between T2DM and the presence of CVD (OR, 2.01; 95%CI, 1.18-3.43; P=.010). CONCLUSIONS: HeFH patients with T2DM have a higher rate of CVD and a less favorable lipid profile, regardless of genetic mutation type. In these patients, T2DM is associated with the presence of CVD

Clinical and genetic differences between heterozygous familial hypercholesterolemia patients with and without type 2 diabetes.

INTRODUCTION AND OBJECTIVES: The lower prevalence of type 2 diabetes mellitus (T2DM) in patients with heterozygous familial hypercholesterolemia (HeFH) could explain why T2DM has not always been identified as an independent predictor of cardiovascular disease (CVD) in different familial hypercholesterolemia cohort studies. The aim of the present study was to evaluate clinical and genetic aspects of HeFH patients with T2DM in the dyslipidemia registry of the Spanish Arteriosclerosis Society. METHODS: HeFH patients were classified according to the presence or absence of T2DM. The clinical, biochemical and genetic characteristics of the 2 groups were compared. RESULTS: Of the 2301 patients with primary hypercholesterolemia included in the registry, 1724 with a probable or definite diagnosis according to the Dutch Lipid Clinic Network score were finally included. HeFH patients with T2DM had a higher rate of CVD and a less favorable lipid profile, with higher total cholesterol (366.9±86.7mg/dL vs 342.0±74.7mg/dL; mean difference 24.894; 95%CI, 5.840-43.949) and non-high-density lipoprotein cholesterol (316.9±87.8mg/dL vs 286.4±75.4mg/dL; mean difference 30.500; 95%CI, 11.211-49.790) levels. No significant differences were found between the groups concerning the specific type of HeFH-causing mutation (P=.720). After adjustment for major risk factors, logistic regression analysis confirmed a relationship between T2DM and the presence of CVD (OR, 2.01; 95%CI, 1.18-3.43; P=.010). CONCLUSIONS: HeFH patients with T2DM have a higher rate of CVD and a less favorable lipid profile, regardless of genetic mutation type. In these patients, T2DM is associated with the presence of CVD.

Comparative efficacy between atorvastatin and rosuvastatin in the prevention of cardiovascular disease recurrence.

BACKGROUND: There is no randomized clinical trials with recurrence of atherosclerotic cardiovascular disease (ASCVD) as a major outcome with rosuvastatin. In order to analyze potential differences in the clinical response to atorvastatin and rosuvastatin in secondary ASCVD prevention, we have analyzed the clinical evolution of those subjects of the Dyslipemia Registry of the Spanish Society of Arteriosclerosis (SEA) who at the time of inclusion in the Registry had already suffered an ASCVD. METHODS: This observational, retrospective, multicenter, national study was designed to determine potential differences between the use of atorvastatin and rosuvastatin in the ASCVD recurrence. Three different follow-up start-times were performed: time of inclusion in the registry; time of first event if this occurred after 2005, and time of first event without date restriction. RESULTS: Baseline characteristics were similar between treatment groups. Among atorvastatin or rosuvastatin users, 89 recurrences of ASCVD were recorded (21.9%), of which 85.4% were coronary. At the inclusion of the subject in the registry, 345 participants had not suffered a recurrence yet. These 345 subjects accumulated 1050 person-years in a mean follow-up of 3 years. Event rates were 2.73 (95% CI: 1.63, 4.25) cases/100 person-years and 2.34 (95% CI: 1.17, 4.10) cases/100 person-years in the atorvastatin and rosuvastatin groups, respectively. There were no statistically significant differences between the two groups independently of the follow-up start-time. CONCLUSIONS: This study does not find differences between high doses of rosuvastatin and atorvastatin in the recurrence of ASCVD, and supports their use as clinically equivalent in secondary prevention of ASCVD.

Aortic Valvular Disease in Elderly Subjects with Heterozygous Familial Hypercholesterolemia: Impact of Lipid-Lowering Therapy.

Hypercholesterolemia and statins are risk factors for aortic stenosis (AS) and vascular calcification, respectively. Whether heterozygous subjects with familial hypercholesterolemia (HeFH) treated with statins are at risk of AS is unknown. We study the prevalence of AS, aortic valve calcification (AoVC), and aortic sclerosis (ASc) in elderly subjects with HeFH in a prolonged statin treatment. Case-control study, cases were adults ≥65 years of age with a genetic diagnosis of HeFH, LDLc >220 mg/dl, and statin treatment ≥5 years. Controls were relatives of HeFH patients, with LDLc <190 mg/dl. Participants underwent a cardiac ultrasound for aortic valve analysis. We studied 205 subjects, 112 HeFH and 93 controls, with mean age 71.8(6.5) years and 70.0(7.3) years, respectively. HeHF, with respect to controls, presented greater gradients of aortic transvalvular pressure, 7.4(7.3) mmHg versus 5.0(2.8) mmHg, and maximum aortic velocity, 1.7(0.7) m/s versus 1.5(0.4) m/s, and lower aortic valve opening area, 2.0(0.7) cm2 versus 2.4(0.6) cm2 (all p < 0.05). AoVC and ASc were also more prevalent in HeFH (p < 0.05 between groups). Moderate/severe AS prevalence was higher among HeFH: 7.1% versus 1.1% (age- and sex-adjusted odds ratio (OR) 8.33, p = 0.03). Independent risk factors for aortic valve disease in HeFH were age and LDLc before treatment. The number of years under statin treatment was not associated with any aortic valve measurement. Subjects ≥65 years with HeFH in prolonged statin treatment show more aortic valvular disease and higher frequency of AS than controls. Life-long elevated LDLc exposure, rather than time of exposure to statins, explains this higher risk.

The Arg499His gain-of-function mutation in the C-terminal domain of PCSK9.

BACKGROUND AND AIMS: Familial hypercholesterolemia (FH) is a monogenic disease characterized by high levels of low-density lipoprotein cholesterol and premature atherosclerotic cardiovascular disease. FH is caused by loss of function mutations in genes encoding LDL receptor (LDLR), and Apolipoprotein B (APOB) or gain of function (GOF) mutations in proprotein convertase subtilisin/kexin type 9 (PCSK9). In this study, we identified a novel variant in PCSK9, p.(Arg499His), located in the C-terminal domain, in two unrelated FH patients from Spain and Italy. METHODS: We studied familial segregation and determined variant activity in vitro. RESULTS: We determined PCSK9 expression, secretion and activity of the variant in transfected HEK293 cells; extracellular activity of the recombinant p.(Arg499His) PCSK9 variant in HEK 293 and HepG2 cells; PCSK9 affinity to the LDL receptor at neutral and acidic pH; the mechanism of action of the p.(Arg499His) PCSK9 variant by co-transfection with a soluble construct of the LDL receptor and by determining total PCSK9 intracellular accumulation when endosomal acidification is impaired and when an excess of soluble LDLr is present in the culture medium. Our results show high LDL-C concentrations and FH phenotype in p.(Arg499His) carriers. In vitro functional characterization shows that p.(Arg499His) PCSK9 variant causes a reduction in LDLr expression and LDL uptake. An intracellular activity for this variant is also shown when blocking the activity of secreted PCSK9 and by inhibiting endosomal acidification. CONCLUSIONS: We demonstrated that p.(Arg499His) PCSK9 variant causes a direct intracellular degradation of LDLr therefore causing FH by reducing LDLr availability.

The island of Gran Canaria: A genetic isolate for familial hypercholesterolemia.

BACKGROUND: Genetic diagnosis of familial hypercholesterolemia (FH) has not been universally performed in the Canary Islands (Spain). OBJECTIVES: This study aimed to genetically characterize a cohort of patients with FH in the island of Gran Canaria. METHODS: Study subjects were 70 unrelated index cases attending a tertiary hospital in Gran Canaria, with a clinical diagnosis of FH, according to the criteria of the Dutch Lipid Clinic Network. Given that 7 of the first 10 cases with positive genetic study were carriers of a single mutation in the LDLR gene [p.(Tyr400_Phe402del)], a specific polymerase chain reaction-based assay was developed for the detection of this variant as a first screening step on the remaining subjects. In those without this mutation, molecular diagnosis was completed using a next-generation sequencing panel including LDLR, APOB, PCSK9, LDLRAP1, APOE, STAP1, and LIPA genes and incorporating copy number variation detection in LDLR. RESULTS: On the whole, 44 subjects (62%) had a positive genetic study, of whom 30 (68%) were heterozygous carriers of the p.(Tyr400_Phe402del) variant. Eleven subjects carried other mutations in LDLR, including the novel mutation NM_000527.4: c.877dupG; NP_000518.1: p.(Asp293Glyfs*8). An unclassified PCSK9 gene variant was found in one subject [(NM_174936.3:c.1496G>A; NP_777596.2: p.(Arg499His)]. Other single patients had mutations in APOB (heterozygous) and in LIPA (homozygous). All identified variants co-segregated with the disease phenotype. CONCLUSIONS: These findings suggest a founder effect for the p.(Tyr400_Phe402del) LDLR mutation in Gran Canaria. A cost-effective local screening strategy for genetic diagnosis of FH could be implemented in this region.

Real-World Outcomes with Lomitapide Use in Paediatric Patients with Homozygous Familial Hypercholesterolaemia.

INTRODUCTION: Homozygous familial hypercholesterolaemia (HoFH) is a rare, autosomal disease affecting the clearance of low-density lipoprotein cholesterol (LDL-C) from circulation, and leading to early-onset atherosclerotic cardiovascular disease (ASCVD). Treatment consists mainly of statins, lipoprotein apheresis (LA) and, more recently, the microsomal triglyceride transfer protein inhibitor lomitapide. Lomitapide is not licensed for use in children, but has been made available through an expanded access programme or on a named patient basis. METHODS: This case series includes 11 HoFH patients in 10 different centres in eight countries, less than 18 years of age (mean 11.6 ± 1.1 years, 64% male), with signs of ASCVD, and who have received treatment with lomitapide (mean dose 24.5 ± 4.3 mg/day; mean exposure 20.0 ± 2.9 months). Background lipid-lowering therapy was given according to local protocols. Lomitapide was commenced with a stepwise dose escalation from 2.5 mg or 5 mg/day; dietary advice and vitamin supplements were provided as per the product label for adults. Laboratory analysis was conducted as part of regular clinical care. RESULTS: In the 11 cases, mean baseline LDL-C was 419 ± 74.6 mg/dL and was markedly reduced by lomitapide to a nadir of 176.7 ± 46.3 mg/dL (58.4 ± 6.8% decrease). Six patients achieved recommended target levels for children below 135 mg/dL, five of whom had LA frequency reduced. In one case, LDL-C levels were close to target when lomitapide was started but remained stable despite 75% reduction in LA frequency (from twice weekly to biweekly). Adverse events were mainly gastrointestinal in nature, occurred early in the treatment course and were well managed. Three patients with excursions in liver function tests were managed chiefly without intervention; two patients had decreases in lomitapide dose. CONCLUSIONS: Lomitapide demonstrated promising effectiveness in paediatric HoFH patients. Adverse events were manageable, and the clinical profile of the drug is apparently similar to that in adult patients. FUNDING: Amryt Pharma.