Sérgio Diogo Giannini

Seven DNA polymorphisms at the candidate genes of atherosclerosis in Brazilian women with angiographically documented coronary artery disease.

The possible association of genetic markers at the apolipoprotein E (HhaI polymorphism), apolipoprotein B (XbaI, EcoRI and Ins/Del polymorphisms), and low-density lipoprotein receptor (LDLR) (AvaII, HincII and PvuII polymorphisms) with coronary artery disease (CAD) was evaluated in 50 Brazilian women with CAD diagnosed by angiography and in 100 healthy women (controls). The frequency of E3/E4 genotype for HhaI polymorphism at the Apo E gene was significantly higher in CAD patients than in controls (40% vs. 14%, respectively, P<0.001). Similarly, the X-X- genotype for XbaI polymorphism was more frequent in CAD individuals than controls (42% vs. 12%, P<0.0001). The A+A+ and P1P1 genotypes for AvaII and PvuII polymorphisms at the LDLR locus were also higher in CAD subjects than controls (44% vs. 16%, P<0.001 and 64% vs. 39%, P<0.05, respectively). The estimated relative risks for CAD in women carrying the E3/E4, X-X-, A+A+ and P1P1 genotypes were 4.1 [95% confidence interval (CI), 3.0-5.6], 5.3 (95% CI, 3.8-7.5), 4.1 (95% CI, 3.0-5.5), and 2.8 (95% CI, 2.2-3.6), respectively. This study demonstrates that Apo E, Apo B and LDLR gene polymorphisms are associated with CAD in Brazilian Caucasian women.

Pvu II intron 15 polymorphism at the LDL receptor gene is associated with differences in serum lipid concentrations in subjects with low and high risk for coronary artery disease from Brazil.

Coronary artery disease (CAD) has a high prevalence in the Brazilian population. Nevertheless, studies of genetic risk factors for CAD in this country have not been sufficiently conducted. We used the Pvu II polymorphism (intron 15) at the low-density lipoprotein receptor (LDLR) gene to study the effect of variation at this locus in determining plasma lipid concentrations in 128 white subjects presenting a lipid profile suggesting high risk for CAD (HRG) and 100 white normolipidemic individuals (controls, CG). The Pvu II polymorphism was detected by PCR-RFLP. The P1P1 genotype for Pvu II polymorphism (homozygous for absence of restriction site) was greater in HRG individuals than in CG subjects (57% vs. 38%, P<0.05). Moreover, the P1P1 genotype was strongly associated with high concentrations of total cholesterol (P=0.0001), triglycerides (P=0. 0295), LDL-C (P=0.0001), and VLDL-C concentrations (P=0.0280) and lower HDL-C concentrations (P=0.0051) in HRG subjects. Similarly, the CG individuals with P1P1 genotype presented high concentrations of total cholesterol and LDL-C compared to other genotypes (P=0. 0001). This study demonstrates the influence of Pvu II polymorphism of the LDLR on serum lipid concentrations of individuals with low and high risk for CAD from Brazil.

Effects of Ava II and Hinc II polymorphisms at the LDL receptor gene on serum lipid levels of Brazilian individuals with high risk for coronary heart disease.

Coronary heart disease (CHD) has presented high prevalence in the Brazilian population. Nevertheless, studies of genetic risk factors for CHD in our country are insufficiently carried out. We have investigated the effects of Ava II (exon 13) and Hinc II (exon 12) polymorphisms at the low‐density lipoprotein receptor (LDLR) gene on circulating lipids of 170 white unrelated individuals presenting a lipid profile with high risk for CHD (HRG) and 130 controls (CG) from São Paulo City, Brazil. Ava II and Hinc II polymorphic regions at the LDLR gene were amplified by PCR and analyzed by enzymatic isotyping. The frequency of the genotypes A+A+ (Ava II) and H+H+ (Hinc II) was greater in HRG group compared to that of the controls (32 vs. 16% and 32 vs. 18%, respectively). Moreover, in the HRG group, A+A+ and H+H+ genotypes were associated with high concentrations of total cholesterol and LDL‐C in serum (P = 0.0001). Our results indicate that Ava II and Hinc II polymorphisms at the LDLR locus contribute to the variability of total cholesterol and LDL‐C levels in HRG individuals. These data suggest that the LDLR polymorphism remains a useful genetic marker for predicting CHD risk. J. Clin. Lab. Anal. 13:251–258, 1999.

Polymorphisms of the low-density lipoprotein receptor gene in Brazilian individuals with heterozygous familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a metabolic disorder inherited as an autosomal dominant trait characterized by an increased plasma low-density lipoprotein (LDL) level. The disease is caused by several different mutations in the LDL receptor gene. Although early identification of individuals carrying the defective gene could be useful in reducing the risk of atherosclerosis and myocardial infarction, the techniques available for determining the number of the functional LDL receptor molecules are difficult to carry out and expensive. Polymorphisms associated with this gene may be used for unequivocal diagnosis of FH in several populations. The aim of our study was to evaluate the genotype distribution and relative allele frequencies of three polymorphisms of the LDL receptor gene, HincII(1773) (exon 12), AvaII (exon 13) and PvuII (intron 15), in 50 unrelated Brazilian individuals with a diagnosis of heterozygous FH and in 130 normolipidemic controls. Genomic DNA was extracted from blood leukocytes by a modified salting-out method. The polymorphisms were detected by PCR-RFLP. The FH subjects showed a higher frequency of A+A+ (AvaII), H+H+ (HincII(1773)) and P1P1 (PvuII) homozygous genotypes when compared to the control group (P<0.05). In addition, FH probands presented a high frequency of A+ (0.58), H+ (0.61) and P1 (0.78) alleles when compared to normolipidemic individuals (0.45, 0.45 and 0.64, respectively). The strong association observed between these alleles and FH suggests that AvaII, HincII(1773) and PvuII polymorphisms could be useful to monitor the inheritance of FH in Brazilian families.

A method to detect the G894T polymorphism of the NOS3 gene. Clinical validation in familial hypercholesterolemia

Abstract An endothelial nitric oxide synthase gene (NOS3) polymorphism in exon 7 (G894T), resulting in Glu298Asp substitution at protein level, has been associated with myocardial infarction, hypertension and coronary atherosclerosis in some populations. This polymorphism is usually identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). However, the procedures described to date do not eliminate the possibility of misclassification and either require confirmation by DNA sequencing or are timeconsuming. In this study, a PCR-RFLP procedure to detect the G894T polymorphism at the NOS3 was optimized by the introduction of a constitutive cleavage site in the amplification product. This cleavage site provides an internal control for enzymatic activity to avoid mistyping. The method was validated by the study of 35 white unrelated individuals with familial hypercholesterolemia and 70 controls. The frequency of the variant allele (T) was similar between both groups (27% vs. 22%, NS), and comparable to the frequency found in other white populations. However, future studies are necessary to confirm these data. In summary, the optimized procedure for detection of the G894T NOS3 polymorphism is rapid, simple, and does not require confirmatory tests. Using this method, we found no association between this polymorphism and familial hypercholesterolemia.

Intervenção sobre tabagismo realizada por cardiologista em rotina ambulatorial

OBJETIVO: Avaliar a efetividade da intervencao sobre o tabagismo, realizada por medico cardiologista em rotina de ambulatorio, utilizando a prescricao de adesivos de nicotina. METODOS: Foram avaliados, consecutivamente, 100 pacientes (50 homens e 50 mulheres), incluindo consulta medica, aplicacao de escore para definicao do grau de dependencia a nicotina, determinacao da concentracao de monoxido de carbono expirado e peso corporeo. Os adesivos foram utilizados entre 8 e 12 semanas, com reducao progressiva da concentracao ate a suspensao (concentracoes de 21, 14 e 7mg) RESULTADOS: A taxa de abstinencia um ano apos o inicio do tratamento foi de 41%, confirmada pela concentracao do monoxido de carbono. CONCLUSAO: A intervencao sobre o tabagismo pode ser realizada em rotina de atendimento cardiologico com resultados satisfatorios. Os adesivos de nicotina sao seguros, bem tolerados, e devem ser utilizados, mais frequentemente, no auxilio aos fumantes, para deixarem de fumar.

Clinical outcome of patients with familial hypercholesterolemia and coronary artery disease undergoing partial ileal bypass surgery

Familial hypercholesterolemia is characterized by high serum levels of total cholesterol and LDL-cholesterol. It may be homozygous or heterozygous. In homozygous patients, LDL-cholesterol levels range from 500 to 1000 mg/dL and coronary artery disease is precocious, usually manifesting itself between the 2nd and 3rd decades of life. The diagnosis is often made by the presence of xanthoma tuberosum and tendinous xanthomas that appear between the 1st and 2nd decades of life. The use of high doses of statins or even unusual procedures (apheresis, partial ileal bypass surgery, liver transplantation, gene therapy), or both, is necessary for increasing survival and improving quality of life, because a reduction in cholesterol levels is essential for stabilizing the coronary artery disease and reducing xanthomas. We report our experience with 3 patients with xanthomatous familial hypercholesterolemia and coronary artery disease, who underwent partial ileal bypass surgery. Their follow-up over the years (approximately 8 years) showed a mean 30% reduction in total cholesterol, with a significant reduction in the xanthomas and stabilization of the coronary artery disease.

First-degree kinship with young coronary artery disease patients markedly increases lipid-level disorders in asymptomatic hypertensives.

Background Association of hypertension and serum lipid disorders has been demonstrated in previous studies. However, there are no investigations about the behaviour of serum lipids in asymptomatic hypertensive individuals who are first degree relatives of young coronary patients. Objective To determine the degree of lipid disorders in Brazilian hypertensive individuals who are first degree relatives of young coronary patients. Methods There were four study groups, 2 in each arm of the study: A) 846 subjects without any evidence of heart disease or diabetes who were first degree relatives of patients who underwent coronary artery bypass grafting (CABG) surgery before 55 years-of-age. Of these subjects, 226 individuals were hypertensive (group Hyp F), and 620 were normotensive (group Normo F): B) 910 hospital employees without evidence of cardiovascular disease and family history of coronary artery disease of whom 152 were hypertensive (group Hyp NF), and 758 were normotensive (group Normo NF). Hypertension was defined as blood pressure greater than 140/90 mmHg. The following serum lipid measurements were performed: Total cholesterol, high-density lipoprotein cholesterol (HDLC), low-density lipoprtein cholesterol (LDLC), and triglycerides. Lipid disorders were defined according to the 2nd Report of the National Cholesterol Education Program (NCEP) (total cholesterol >240 mg/dl; LDL0160 mg/dl; triglycerides > 200mg/dl). The frequency of lipid disorders in each group was calculated. Subjects were classified according to their body mass index (BMI) as normal, overweight, or obese. The following statistical analyses were performed as indicated: ANOVA (with Tukeys corrections for multiple comparisons), chi-square (χ2), and odds ratio (OR). Results Hyp F subjects had significantly higher total cholesterol, LDLC and triglyceride levels, and significantly lower levels of HDLC than all other groups. There was a higher frequency of lipid disorders in Hyp F subjects than in Hyp NF individuals, with a significant OR of 1.71 (Cl 1.26-2.32) and 2.09 (Cl 1.48-2.72) for total cholesterol and LDLC respectively. When compared to Normo F subjects, Hyp F individuals had significantly higher risk of having lipid disorders: Total cholesterol (OR = 8), LDLC (OR = 6), and triglycerides (OR = 5). There was a higher frequency of obesity among Hyp F patients than in all other groups. The frequency of subjects who were overweight or obese was higher in Hyp F than in Hyp NF subjects. Conclusion Hypertensive patients who were first degree relatives of patients revascularized at a young age had a higher prevalence of lipid disorders, particularly higher total cholesterol and LDLC, than hypertensive individuals without this family history. These individuals may have a greater genetic propensity to develop lipid disorders.

Simvastatin in the treatment of elderly patients with primary hypercholesterolemia

Abstract Twenty elderly patients (14 women, 6 men) with primary hypercholesterolemia (total cholesterol >260 mg/dl) were treated for 42 months with simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. Mean age was 69 ± 3 years (range, 65 to 72 years). Eighteen patients had coronary heart disease and two had transient cerebral ischemia; all patients were unresponsive to dietary changes. Clinical, ophthalmologic, and laboratory evaluations were performed periodically. Simvastatin dosages ranged from 2.5–20 mg/day initially, with maintenance doses from 5–40 mg/day (mean, 22 ± 12 mg/day). Total cholesterol (TC), plasma triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and very low-density lipoprotein cholesterol (VLDL-C) levels and TC:HDL-C and LDL-C:HDL-C ratios were determined during the placebo baseline period and active treatment period. When the placebo baseline period was compared with the final active treatment period significant reductions of TC levels (306.1 ± 22.7 and 213.1 ± 22.5; mean reduction = 30.2%) and LDL-C levels (223.3 ± 27.3 and 136.3 ± 20.3; mean reduction = 40.4%) were seen. There was a significant increase in HDL-C levels (49.9 ± 8.7 and 51.9 ± 8.9; mean increase = 5.1%). There were also significant reductions in TC:HDL-C and LDL-C:HDL-C ratios, of 6.2 ± 1.0 and 4.2 ± 0.8 (mean reduction = 34.0%) and 4.5 ± 0.9 and 2.7 ± 0.6 (mean reduction = 43.4%), respectively. Although a 20.4% reduction in TG levels (166.4 ± 53.7 to 117.5 ± 34.8) was seen, it was not statistically significant. In conclusion, simvastatin had significant effects on TC, LDL-C, and HDL-C levels as well as TC:HDL-C and LDL-C:HDL-C ratios compared with placebo and the reductions observed at the beginning of the study remained constant throughout the investigation. TG, VLDL-C, and HDL-C levels did not show uniform responses for all patients. There were no adverse effects requiring interruption of treatment. The present study confirms the validity of long-term therapy with simvastatin in the elderly.

MUSCULAR RESPONSE TO MECHANICAL OVERLOAD IN HYPERCHOLESTEROLEMIC PATIENTS TREATED WITH SIMVASTATIN: ISOKINETIC EVALUATION THROUGH COMPUTERIZED DYNAMOMETRY

Abstract This study was designed to evaluate changes in the functioning of striated muscle during treatment with simvastatin. Muscular activity was assessed by computerized dynamometry, which was used to determine maximum torque, total work performed, maximum power, torque acceleration energy, endurance ratio, and recovery ratio. Total cholesterol, triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol (LDL-C) were determined using Friedewalds formula. Fifteen outpatients (10 women and 5 men; mean age, 55.7 ± 7.8 years) with primary hypercholesterolemia (LDL-C >4.14 mmol/L) who had not received lipid-lowering therapy in the previous 30 days and who were participating in atherosclerotic-disease primary-prevention programs were selected. All patients received simvastatin 10 mg/d for 30 days, followed by 20 mg/d for 30 more days. Dynamometric measurements were obtained on three occasions: (1) at baseline; (2) after 30 days of treatment with simvastatin 10 mg/d; and (3) after 30 more days of treatment with simvastatin 20 mg/d. On the same days, blood samples were collected for determination of serum lipid levels (total cholesterol, triglycerides, and high-density lipoprotein cholesterol) and serum enzyme activities (creatine kinase, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyltransferase), and electroneuromyographic tests were performed to analyze sensitive and motoneuron conduction response.