Perfil de Prescrição de Estatinas e de Níveis Lipêmicos em Ambulatórios de Hospital Terciário Público / Statins Prescriptions and Lipid Levels in a Tertiary Public Hospital

Resumo Fundamento: O surgimento de nova classe de medicamentos com elevada capacidade de reduzir o LDL-colesterol (LDL-c) renovou o interesse na caracterização da hipercolesterolemia familiar (HF). Pouco se conhece do perfil lipídico de pacientes em atendimento terciário em nosso meio para caracterizar a real ocorrência de HF, que começa a ser suspeitada com níveis de LDL-c acima de 190mg/dL. Objetivos: O estudo avaliou o perfil lipídico (colesterol total [CT] e LDL-c) de pacientes de hospital público terciário. Métodos: Estudo retrospectivo de avaliação de prescrições de estatinas e resultados dos lipídios. O nível de significância foi estabelecido em 5%. Resultados: Em 1 ano, 9.594 indivíduos receberam prescrição ambulatorial de estatinas, 51,5% do gênero feminino, idade média de 63,7±12,9 anos (18 a 100 anos). Trinta e duas especialidades prescreveram estatinas, sendo a cardiologia responsável por 43%. Cerca de 15% das prescrições não tinham dosagem recente de CT, e 1.746 (18,0%) não apresentavam resultado recente de LDL-c. A ocorrência de LDL-c > 130mg/dL e < 190mg/dL ocorreu em 1.643 (17,1%) casos, e 228 (2,4%) apresentaram LDL-c ≥ 190mg/dL dentre os que utilizavam estatinas nas diversas doses. Apenas duas estatinas foram utilizadas: sinvastatina e atorvastatina, e a primeira foi prescrita em 77,6% das receitas. Conclusão: Nesta coorte transversal de hospital terciário, foi possível verificar que a prescrição de estatinas é disseminada, mas que a obtenção de metas adequadas de CT e LDL-c não é atingida em grande percentual, e que há, possivelmente, significativo contingente de portadores de HF que necessitariam ser investigados por suas implicações prognósticas.

Abstract Background: The development of a new class of medications that are highly capable of reducing LDL-cholesterol renewed the interest in the characterization of familial hypercholesterolemia patients. Nevertheless, little is known about the lipid profile of patients in tertiary healthcare centers in Brazil in order to better estimate the real occurrence of familial hypercholesterolemia, with initial suspect of LDL-cholesterol levels above 190 mg/d/L. Objectives: This study evaluated the lipid profile (total cholesterol and LDL-cholesterol) in ambulatory patients from a general tertiary public hospital. Methods: Retrospective study comparing prescriptions of statins and lipid profile results. The significance level was established in 5%. Results: In one year, 9,594 individuals received statin prescriptions, of whom 51.5% were females and the mean age was 63.7±12.9 years-old (18 to 100 years-old). Thirty-two medical specialties prescribed statins. Cardiology was responsible for 43% of the total. Nearly 15% of those patients with a prescription did not have a recent total cholesterol result and 1,746 (18%) did not have a recent LDL-cholesterol measurement. The occurrence of the latter between 130 and 190 mg/dL was present in 1,643 (17.1%) individuals, and 228 (2.4%) patients had an LDL-cholesterol ≥190mg/dL among those using statins at distinct doses. Only two statins were used: simvastatin and atorvastatin. The first was prescribed in 77.6% of the prescriptions. Conclusion: In this cross-sectional cohort at a tertiary general hospital, statins have been widely prescribed but with little success in achieving recognized levels of control. There is probably a significant number of FH individuals in this cohort that need to be properly diagnosed in order to receive adequate treatment due to its prognostic implications.

Nuevos fármacos para el tratamiento de la hipercolesterolemia / New lipid lowering agents

Statins are the preferred treatment for hypercholesterolemia and several studies have demonstrated their long-term safety and efficacy in reducing cardiovascular morbidity and mortality. However, in some cases of severe hypercholesterolemia such as homozygous and heterozygous familial hypercholesterolemia or statin intolerant patients, statins can be less efficient. In recent years, new lipid-lowering agents with novel mechanisms of action have been developed to reduce LDL-cholesterol in patients with severe hypercholesterolemia, associated or not to conventional lipid-lowering therapy. These therapies include microsomal transfer protein inhibitor (Lomitapide), antisense oligonucleotide to Apo B100 (Mipomersen) and monoclonal antibodies against Proprotein convertase subtilisin/kexin type 9 (PCSK9). Different studies have shown the great effectiveness of these new therapies. Short-term studies confirmed their adequate security profile, especially in patients with homozygous familiar hypercholesterolemia or severe hypercholesterolemia. Some of these agents have been also tested in statin-intolerant patients. However, long-term studies are needed to evaluate their safety, effectiveness and impact on cardiovascular risk reduction.

Familial Hypercholesterolemia and the Atherosclerotic Disease

Familial hypercholesterolemia (FH) is associated with premature atherosclerotic cardiovascular diseases, and is inherited as an autosomal dominant trait. The prevalence of heterozygous FH is one in five hundred people. Owing to dysfunctional low density lipoprotein (LDL) receptors due to genetic mutations, serum low density lipoprotein-cholesterol (LDL-C) levels are considerably increased from birth. FH is clinically diagnosed by confirmation of family history and characteristic findings such as tendon xanthoma or xanthelasma. Thus, clinical concern and suspicion are important for early diagnosis of the disease. Current guidelines recommend lowering LDL-C concentration to at least 50% from baseline. Statins are shown to lower LDL-C levels with high safety, and thus, have been the drug of choice. However, it is difficult to achieve an ideal level of LDL-C with a single statin therapy in the majority of FH patients. Alternatively, lipid lowering combination therapy with the recently-introduced ezetimibe has shown more encouraging results.

SSCP screening of mutation in exon 13 of low density lipoprotein receptor gene in Chinese familial hypercholesterolemia patients / 中华检验医学杂志

Objective To investigate the application of polymerase chain reaction and single strand conformation polymorphism analysis(PCR-SSCP)to the screening of gene mutation of exon 13 of the LDLR gene in familial hypercholesterolemia(FH).Methods Peripheral blood DNA of 16 clinically diagnosed FH patients was extracted and the exon 13 coding region of the LDLR gene was amplified by PCR.PCR products were separated by optimized SSCP electrophoresis and visualized by silver staining.DNA fragments with abnormal mobility were sequenced to determine the nature and position of mutations.Results The SSCP electrophoresis conditions were optimized as 8%polyaerylamide(degree of cross linking 49:1)gel without glycerin at a electrophoresis temperature of 10℃ or 8%polyacrylamide gel with 5%glycerin at room temperature,gel thickness of＜0.4 mm,and a voltage of 5 V/cm.DNA fragments were well resolved with the conditions and sequencing of the abnormal bands resuhed in detections of missense mutations of A606T,D601N,Y601D and G636V together with a synonymous mutation of 1959C→T in 4 patients and a sole synonymous mutation of 1959C→T in other 4 patients.Conclusion PCR-SSCP is an effective method for the screening of exon13 mutations of LDLR gene in FH patients.

Gene mutations in low-density lipoprotein receptor in one Chinese padigree with homozygous familial hypercholesterolemia / 中华检验医学杂志

Objective To investigate low density lipoprotein receptor (LDLR)gene mutation in familial hypercholesterolemia (FH) patients. Methods The proband was given clinical diagnosis of homozygous FH based on marked features and blood lipid tests results. After apoB100R3500Q mutation was excluded, the promoter region and all of the 18 exons of LDLR gene were amplified by touch-downpolymerase chain reaction (PCR). The PCR products were analyzed by single-strand conformationalpolymorphism (SSCP). The PCR products with abnormal single strands were sequenced directly. Thesecondary structures of the mutational and wild type proteins were analyzed and compared byANTHEPROT5.0, and then the tertiary structures of the mutant and wild type LDLR were predicted atSWISS MODEL homepage online. Results A homozygous mutation A606T at exon 13 of the patients wasfound by SSCP and confirmed by DNA sequencing. GOR Ⅰ method in ANTHEPROT5.0 indicates that therandom coils and turns would replace some helixes at the mutation site. The online prediction from theSWISS MODEL homepage indicates the backbone structure of the mutant LDLR has no difference from thewild type one. Conclusion The results suggest the A606T mutation of LDLR gene is the cause of the FH inthis pedigree.

A clinical study on quantitative evaluation of carotid elasticity in familial hypercholesterolemia by echo tracking technique / 中华超声影像学杂志

Objective With a newly developed ultrasoundbased technique named as echo tracking,to determine the carotid stiffness and compliance in familial hypercholesterolemia(FH) patients.Methods The study population included 8 FH patients with 3 male and 4 female at a mean age of((17.22)?(5.69)) years and 7 normal controls. With the echo tracking technique,the quantitative parameters of Ep,? and the arterial compliance(AC) were detected.Results Ep,? and AC of the subtotal FH patients were higher than that of controls,the statistical significance was found in ? of both common carotid arteries,Ep of right common artery and AC of left artery in two groups.Conclusions The echo tracking technique may be a promising modality for noninvasive estimation of the atherosclerotic proceeding in FH patients.

A simple assay for LDL receptor activities in human periphral lymphocytes / 中国病理生理杂志

Periphral lymphocytes suspended in RPMI-1640 were incubated in plates of 96 wells for 96 hours with 50 ?g/ml of PHA, various concentrations of LDL-ch and0.6 ?M of mevinolin (experimental) or equal volume of its solvent-dimethyl sulfoxide (control). 6 hours before harvesting cells, 0.5?Ci of ~3H-TdR was added to each well, then cells were harvested and their cpm counted. The LDL receptor activity was expressed as mevinolin-mediated lymphocyte proliferation inhibition rate which can be calculated by the following equation:Percent Inhibition Rate=(1-cpm exp./cpm con.)100%.It was found that the lymphocyte proliferation inhibition rate at 5?g/ml of LDL-ch was less than 20% for normal and non-FH hyperlipidemic subjects, 25-55% for FH heterozygotes and over 60% for FH homozygotes. Thus, FH patients were distinguished from normal subjects and non-FH hyperlipidemic patients.