An association of ABCG8: rs11887534 polymorphism and HDL-cholesterol response to statin treatment in the Polish population.

BACKGROUND: Variation in lipid changes in response to statin treatment is associated with genetic polymorphism. Sterolin-1, encoded by ABCG5, and sterolin-2, encoded by ABCG8, together form a sterol transporter. There are some reports indicating association of rs11887534 (ABCG8:c.55G > C) polymorphism with lipid concentrations, both prior to and after statin treatment. The aim of this study was to analyze both baseline plasma lipids and their concentrations in response to statin treatment with regard to ABCG8: rs11887534 polymorphism in Caucasian patients of Polish origin. METHODS: The study group consisted of 170 consecutive adult out-patients treated with atorvastatin or simvastatin for a minimum of 2 months. Concentrations of triglycerides (TG), total cholesterol (TC), LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) were measured before and after statin treatment. The ABCG8 polymorphism was identified by mini-sequencing genomic DNA extracted from peripheral blood leukocytes. RESULTS: There were no significant differences in regard to ABCG8 variants for baseline TG, TC, LDL-C and HDL-C as well as for TG, TC or LDL-C concentrations after statin treatment. However, patients carrying at least one C allele showed a decrease in post-statin HDL-C concentrations and the absolute and relative changes between post- and pre-statin HDL-C concentrations were negative in contrast to positive values in wild-type homozygotes. CONCLUSIONS: Our results suggest that the c.55C allele of the ABCG8: rs11887534 polymorphism might be associated with decrease in HDL-cholesterol in response to statin treatment in Polish patients.

C677T polymorphism of the methylenetetrahydrofolate reductase gene and the risk of ischemic stroke in Polish subjects.

Hyperhomocysteinemia is reported to be an independent risk factor for the development of ischemic stroke. Several studies on genetic variants of methylenetetrahydrofolate reductase (MTHFR, which plays a crucial role in regulation of plasma homocysteine concentration) reported an association between C677T gene polymorphism and stroke in some Asian populations. No study but one detected this association in Caucasians. The purpose of the present case-control study was to find a relationship between MTHFR genotypes and stroke in a Polish population. MTHFR genotypes were determined by PCR in 152 patients with ischemic stroke from northwestern Poland and in 135 consecutive newborns from the same population. The TT genotype and the T allele were significantly more frequent in patients than in the control group (11.8% vs. 4.4%, and 34.5% vs. 21.5%, P<0.01). When males and females were analyzed separately, the differences were statistically significant in both genders. It is concluded that presence of the T allele is a risk factor for ischemic stroke in Polish subjects.

[Polymorphism of genes coding for angiotensin I converting enzyme and methylenetetrahydrofolate reductase in patients with ischemic heart disease]. / Polimorfizm genów enzymu konwertujacego angiotensyne I oraz reduktazy metylenotetrahydrofolianu u pacjentów z choroba niedokrwienna serca.

Due to its multifarious biological activity the renin-angiotensin system occupies a special position among risk factors of ischemic heart disease. The discovery of I/D polymorphism of the ACE gene led to a better understanding of genetic control of this enzyme. Hyperhomocysteinemia is an independent risk factor of ischemic heart disease. Elevated plasma levels of homocysteine may be due to improper diet (e.g. shortage of folic acid) and/or genetic influence. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the metabolism of homocysteine. The present study was performed in 100 patients (14 women and 86 men, mean age 54.2 +/- 9.2 years) with a history of myocardial infarction. The control group included 100 patients (10 women and 90 men, mean age 52.3 +/- 10 years) without such history. PCR was used to detect I/D ACE and C677T MTHFR polymorphisms. Genomic DNA was isolated from peripheral blood nuclear cells and amplified by PCR with two pairs of primers flanking the polymorphic regions. The restriction enzyme Hinf I was used to identify genotypes of the MTHFR polymorphism. No difference between both groups was found concerning the distribution of I/D ACE genotypes (31% II, 51% ID, 18% DD in the study group; 30% II, 57% ID, 13% DD in the control group; Tab. 1) or the distribution of C677T MTHFR genotypes (46% CC, 45% CT, 9% TT in the study group; 39% CC, 50% CT, 11% TT in the control group; Tab. 2). There was a significant effect of I/D genotype on ACE activity (IU/L) in the study (II = 18.2 +/- 17.9; ID = 33.5 +/- 19.9; DD = 68.9 +/- 21.9) and in the control group (II = 24.2 +/- 18.1; ID = 31.5 +/- 20.9; DD = 51.4 +/- 19.5; Tab. 3). No correlation was confirmed between ACE or MTHFR genotypes and age at infarction or left ventricular mass (Tabs. 4, 5, 6). The results indicate that neither the I/D ACE nor the C677T MTHFR polymorphisms are associated with risk of myocardial infarction in the Polish population.

[C677T gene polymorphism of methylenetetrahydrofolate reductase (MTHFR) in patients with myocardial infarction]. / Polimorfizm C677T genu reduktazy metylenotetrahydrofolianu (MTHFR) u chorych po przebytym zawale miesnia sercowego.

Hyperhomocysteinemia is thought to be an independent risk factor for coronary heart disease. Increased plasma homocysteine level can result from malnutrition (e.g. folate deficiency) and/or genetic-related disturbances. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the synthesis of 5-methyltetrahydrofolate, the methyl donor for homocysteine remethylation to methionine. Transition of cytosine (C) to thymidine (T) at nucleotide position 677 of MTHFR gene causes alanine 226-to-valine substitution, and in consequence results in decreased enzyme activity and increased homocysteine level. Therefore, the aim of our study was to estimate the frequency distribution of C677T MTHFR polymorphism in patients with past myocardial infarction (MI), and to evaluate the association between this polymorphism and age of MI onset or left ventricular mass (LVM). The study was performed in 100 MI patients aged from 34 to 76 years and in control group consisted of 100 age- and gender-matched non-MI subjects. Applying PCR followed by Hinf I digestion of amplification products no significant difference in the frequency distribution of C677T MTHFR genotypes has been found between both groups (MI patients: 46% CC, 45% CT and 9% TT, and control group: 39% CC, 50% CT and 11% TT, respectively). No significant association between MTHFR genotypes and age of MI onset or LVM has been found in MI group. The results of our study suggest that C677T polymorphism of MTHFR gene is not a risk factor for myocardial infarction in Polish population.

[Fibrinogen (Fb) concentrations in patients with ischaemic heart disease undergoing coronary angiography]. / Analiza stezenia fibrynogenu (Fb) u chorych z angiograficznie udokumentowana choroba niedokrwienna serca.

Increasing evidence suggests the role of hemostatic risk factors in the development of ischemic heart disease (IHD). A raised plasma fibrinogen has been related to increased risk of IHD. The aim of the study was to determine the relationship between plasma fibrinogen and the coronary vessels state based on the coronary angiogram. 119 patients undergoing coronary angiography were classified into 5 groups according the severity of IHD: Group 0 without significant atherosclerotic lesions (control group), Group 1 with single vessel disease, Groups 2, 3 with multivessel disease (two and three affected arteries, respectively) and Group 4 with positive history of myocardial infarction. A statistically nonsignificant rise in fibrinogen levels in Groups 1, 2, 3 (3.9 +/- 0.8 g/l, 4.0 +/- 0.9 g/l, 4.1 +/- 0.9 g/l, respectively) as compared to control Group 0 (3.7 +/- 0.7 g/l) was found. In Group 4 plasma fibrinogen was significantly lower (2.8 +/- 0.6 g/l) comparing to Group 0 (p < 0.05). In addition plasma fibrinogen was positively correlated with blood pressure. These results supports the role of raised plasma fibrinogen in the pathogenesis and development of IHD.

Effects of perindopril treatment on hemostatic function in patients with essential hypertension in relation to angiotensin converting enzyme (ACE) and plasminogen activator inhibitor-1 (PAI-1) gene polymorphisms.

BACKGROUND AND AIM: An imbalance in the hemostatic system is a frequent finding in untreated essential hypertension (HT), and it has been shown that treatment with angiotensin converting entyme (ACE) inhibitors improves hemostatic function. In order to elucidate the role of genetic factors, we studied hemostasis in patients with untreated and treated HT and correlated the results with ACE I/D and plasminogen activator enhibitor-1 (PAI-1) 4G/5G gene polymorphisms. METHODS AND RESULTS: Forty-three males with HT (mean age 31.7 +/- 6.8 years) were compared with 34 age and gender-matched controls. All of the patients were treated with perindopril (4 mg/day) and, after one and six months of therapy, their levels of plasma fibrinogen (Fb), t-PA antigen, PAI-1 antigen, von Willebrand factor (vWF), ACE activity and blood pressure were measured. ACE and PAI-1 genotypes were identified by means of the polymerase chain reaction on DNA isolated from peripheral blood lymphocytes. Untreated patients had significantly higher levels of Fb, PAI-1 (p < 0.01) and t-PA (p < 0.05) regardless of their ACE or PAI-1 genotypes. Perindopril reduced blood pressure regardless of ACE or PAI-1 genotype (p < 0.001). ACE II homozygotes showed the greatest decrease in ACE activity (p < 0.01) and a significant reduction in Fb levels (p < 0.05) after just one month of treatment. Analysis of the group as a whole revealed an increase in t-PA antigen levels after six months of treatment, regardless of ACE or PAI-1 genotype (p < 0.01). CONCLUSIONS: Our results show that essential hypertension predisposes to the procoagulant state characterized by hyperfibrinogenemia and hypofibrinolysis. Perindopril reduced fibrinogen levels in ACE II homozygotes due to its more potent inhibitory action on the renin-angiotensin system in such patients. It improved fibrinolysis by increasing t-PA levels regardless of ACE and PAI-1 genotype.