Gene-gene interaction of ACE I/D, endothelial nitric oxide synthase 4 a/b and ApoE does not affect coronary artery disease severity

OBJECTIVES

Previous studies have shown the impact of angiotensin converting enzyme (ACE) insertion/deletion (I/D), endothelial nitric oxide synthase (eNOS) polymorphisms and ApoE genotypes on coronary artery disease (CAD). The aim of this study is to investigate the relationship between the genetic polymorphisms and the severity of CAD and to evaluate their potential interactions.

MATERIAL AND METHODS

All patients underwent coronary angiography; coronary score (CS) and severity score (SS) were calculated for them. ACE I/D, eNOS and ApoE polymorphisms were detected by polymerase chain reaction (PCR).

RESULTS

Neither CS nor SS showed a direct relationship with eNOS and ApoE genotypes. CS and SS were found to be high in patients carrying the ACE DD allele (p = 0.034 and p = 0.009). In the gene interactions, there was an increase in the SS only in patients with coexisting eNOS b/b genotype and ACE DD allele (p = 0.043).

CONCLUSIONS

The interactions of the gene polymorphisms investigated don't play an important role in determining an individual's risk for the severity of CAD.

ACE Gene Polymorphism in Turkish Children with Nephrotic Syndrome

Since 1990, the role of angiotensin converting enzyme (ACE) gene polymorphism in various renal and cardiac diseases is still debated. This study comprised 71 pediatric patients with nephrotic syndrome, 47 males (66%) and 24 females (34%) with a mean age of 57.4 +/- 37.6 months, and a control group of 83 healthy males (59%) and 57 healthy females (41%) with a mean age of 505 +/- 160.5 months. The distribution of the ACE genotype in the control group was II, 11%; ID, 53%; and DD, 36%, and the nephrotic syndrome was II, 4%; ID, 78%; and DD, 18%. Angiotensin-converting enzyme genotypes were significantly different between patients and control groups (p<0.05). The study groups consisted of 52 (73%) with steroid-sensitive nephrotic syndrome (SNSS) and 19 (27%) with steroid-resistant nephrotic syndrome (SRNS). The distribution of the ACE genotype was II, 6%; ID, 75%; and DD, 19% in the SSNS population and ID, 84% and DD, 16% in the SRNS population. No statistically significant difference was found between steroid sensitivity and ACE genotypes (p=0.5). The results show that ACE I/D polymorphism does not contribute to the steroid resistance, even though this study indicates that the presence of the I/D genotype has a much higher risk--approximately 2.8 times--of having nephrotic syndrome. Further studies with a larger number of patients are needed.

Genetic dilemma: eNOS gene intron 4a/b VNTR polymorphism in sepsis and its clinical features in Turkish children

The role of endothelial nitric oxide synthase gene intron 4 a/b (eNOS4a/b) variable number of tandem repeats (VNTR) polymorphism in various diseases was investigated. We investigated whether this polymorphism is associated with susceptibility to sepsis and its clinical features such as acute respiratory distress syndrome (ARDS), multiorgan dysfunction syndrome (MODS) and shock. eNOS4a/b VNTR polymorphism was determined by the polymerase chain reaction in 100 children with sepsis and in 134 healthy controls. The genotype distribution of eNOS4 was not different between the patients and controls (p=0.44). There was no statistically significant association between genotypes/allele frequency and outcomes like mortality, MODS, ARDS, and shock (p>0.05). This is the first study that evaluates the effect of eNOS4a/b polymorphism in sepsis. We were unable to show a relationship between eNOS gene intron 4 a/b VNTR polymorphism and MODS, ARDS, mortality and shock. Larger studies that do research on the interaction of such genes are needed to clarify the association between eNOS4a/b polymorphism and sepsis.

Procollagen type I carboxy-terminal peptide shows left ventricular hypertrophy and diastolic dysfunction in hypertensive patients

BACKGROUND

An excess of myocardial collagens in hypertension is a result of increased collagen synthesis and unchanged or decreased collagen degradation. Increased collagen content, which is shown by the procollagen type I carboxy-terminal peptide (PIP), promotes cardiac remodeling and function abnormalities.

OBJECTIVES

The objectives of this study were to assess PIP levels as a marker of myocardial collagen synthesis and to investigate the relationship between PIP levels and left ventricular mass index (LVMI) as well as diastolic function in patients with mild-to-moderate essential hypertension.

METHODS

The study subjects were divided into three groups: healthy subjects (Group I, n=30); hypertensive patients without left ventricular hypertrophy (Group II, n=30); and patients with left ventricular hypertrophy (Group III, n=30). Left ventricular diastolic function was assessed by standard echocardiography and tissue Doppler imaging. Serum PIP was measured by radioimmunoassay.

RESULTS

The serum concentration of PIP was higher in Group III than in Groups I and II (P<.001). A positive correlation was found between serum PIP and LVMI in hypertensive patients (r=.57, P<.001). Patients with diastolic dysfunction (DD) had significantly higher PIP levels as compared with patients without DD (177.3+/-52.25 vs. 138.8+/-38.0 microg/L, P<.001). The cutoff values of PIP to predict left ventricular hypertrophy and DD were 155.0 microg/L (sensitivity, 84%; specificity, 73%) and 150.2 microg/L (sensitivity, 71%; specificity, 70%), respectively.

CONCLUSION

An elevated serum concentration of PIP shows left ventricular hypertrophy and DD in the course of hypertension and may be used to follow up on the efficacy of the antihypertensive treatment used.

Biochemical indicators and cardiac function tests in chronic alcohol abusers

AIM

To determine the effect of chronic alcohol abuse on cardiac function, antioxidant system, trace elements, and liver function tests.

METHODS

Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT), superoxide dismutase (SOD), malondialdehyde (MDA), as well as zinc, magnesium, and copper were assayed in 25 chronic alcoholic patients and their 25 healthy relatives matched in age and gender. Echocardiographic parameters were evaluated for subjects.

RESULTS

Mean corpuscular volume (96.7 fL vs 92.4 fL) and mean corpuscular hemoglobin levels (31.4 pg vs 30.5 pg) were found to be significantly increased in the patient group (P=0.002 and P=0.048, respectively). The results of the SOD and MDA assays showed no significant differences between the two groups. AST (38.7 U/L vs 22.1 U/L) and GGT (104.2 U/L vs 34.2 U/L) levels were found to be significantly increased in the patient group compared with controls (P=0.005 and P<0.001, respectively). Magnesium (1.6 mmol/L vs 1.8 mmol/L) and zinc levels (14.9 micromol/L vs 19.2 micromol/L) were significantly decreased, whereas copper levels (19.3 micromol/L vs 17.9 micromol/L) were increased in alcoholics (P=0.042, P<0.001 and P=0.003, respectively). Echocardiographic examination showed a significant decrease in mitral and tricuspid ratio of peak early and atrial flow velocity (E/A ratio) in alcoholics.

CONCLUSION

Decrease in mitral and tricuspid E/A ratios accompanied with low levels of magnesium and zinc, and increased levels of copper indicate that alcoholics already have heart muscle disease even chronic alcohol exposure.

eNOS gene intron 4 a/b VNTR polymorphism is a risk factor for coronary artery disease in Southern Turkey

BACKGROUND

Nitric oxide (NO) plays a major role in the regulation of vascular tone Associations between NO genotypes, coronary artery disease (CAD) and other risk factors have been described by many authors. The aim of this study was to investigate the role of endothelial nitric oxide synthase (eNOS) gene intron 4 a/b variable number of tandem repeats (VNTR) polymorphism and other risk factors in the development of CAD in subjects living in Southern Turkey.

METHODS

Two-hundred and sixty-six patients (154 males and 112 females, aged between 30 and 80 years, mean 52.4+/-10.3) whose coronary arteries were evaluated by means of coronary angiography were enrolled in the study. Of the total, 133 had CAD (Group I) and the remaining had normal coronary arteries (Group II). The eNOS gene intron 4 a/b VNTR polymorphism was analyzed by polymerase chain reaction. The plasma lipid levels and other risk factors were also determined in all subjects.

RESULTS

The a allele frequencies and genotypes carrying a allele were significantly higher in Group I. Plasma lipids, except HDL-C, were also increased in this group. We found that hypertension (HT), diabetes mellitus (DM), male gender, age and smoking were the independent predictors of CAD.

CONCLUSION

a allele of eNOS intron 4 a/b VNTR polymorphism is not an independent predictor of CAD. eNOS intron 4 a/b polymorphism (presence of a allele) is a risk factor in addition to HT, DM, male gender, age and smoking for the development of CAD in Southern Turkey.

Relation between age and gender differences in plasma triglyceride concentrations and coronary artery disease in Southern Turkey

BACKGROUND

Coronary artery disease (CAD) is still a leading cause of morbidity and mortality in both genders in Turkey as well as other countries. The role of plasma triglycerides (TG) as a CAD risk factor has been controversial. We investigated the relation between age and gender differences in plasma TG and CAD in patients with angiographically proven CAD.

METHODS

The study population consisted of 937 patients (605 males and 332 females, aged between 32 and 82 years). The patients were divided into three age groups as < 45, 45-59 and > or = 60 years. Risk factors were considered as hypertension, hyperlipidemia, diabetes mellitus, cigarette smoking and family history. Hypertriglyceridemia was defined as TG concentration > 150 mg/dl (> 1.69 mmol/l).

RESULTS

Of the total, 608 had CAD. TG was an independent risk factor for CAD only in women (p < 0.05). There was also a positive correlation between TG concentrations and number of the diseased vessels only in women (p = 0.001, r = 0.2).

CONCLUSION

High TG concentrations increase CAD risk more in women than in men in Southern Turkey. Triglycerides should be taken into consideration as an important risk factor especially in women > 45 years of age.

Effects of apolipoprotein E genotypes and other risk factors on the development of coronary artery disease in Southern Turkey

BACKGROUND

Apolipoprotein E (apoE) plays a major role in lipoprotein metabolism and lipid transport. Associations between apoE genotypes, coronary artery disease (CAD) and other risk factors have been described by many investigators. The aim of this study was to investigate the role of apoE gene polymorphism and other risk factors in the development of CAD in subjects whose coronary arteries were evaluated by means of coronary angiography.

METHODS

The study population consisted of 199 subjects (114 male and 55 female). Of the total, 107 had CAD. The apoE gene was amplified by polymerase chain reaction (PCR) and then digested by CfoI restriction enzyme. The plasma lipid levels and other risk factors were also determined in all subjects.

RESULTS

The epsilon2 and epsilon4 allele frequencies and genotypes carrying epsilon4 allele were significantly higher in CAD (+) patients. Plasma lipids except triglycerides were increased in CAD (+) cases. We found that apoE genotypes, HT, DM, male gender, age and smoking were the independent predictors of CAD. There was no association between apoE alleles and lipids.

CONCLUSION

We conclude that apoE polymorphism (presence of epsilon4 allele) is associated with the development of CAD in Southern Turkey. In our study, we did not observe any effect of apoE alleles on lipid levels.

Genetic heterogeneity of beta-thalassemia at Cukurova in southern Turkey

Beta-thalassemia is the most common genetic abnormality causing health problems worldwide. Cukurova, in the southern part of Turkey, being on the Mediterranean, is in the thalassemic belt. Since there is no cure for the disease at present, the frequency of the mutation types of beta-thalassemia must first be identified to aid in clinical follow-up and prenatal diagnosis. Carriers identified during a screening survey and patients referred to our laboratory were studied for this purpose. After routine hematological analysis molecular screening was performed by the amplification refractory mutation system and DNA sequencing. The frequency of the common mutations were: IVS-I-110 (G-->A) 57.3%, IVS-I-1 (G-->A) 8.3%, codon 39 (C-->T) 6.4%, IVS-I-6 (T-->C) 5.7%, frameshift codon 8 (-AA) 5.7%, -30 (T-->A) 4.7%, IVS-II-1 (G-->A) 3.4%, IVS-II-745 (G-->C) 2.8%, and frameshift codon 5 (-CT) 1.1%. Some rare mutations (1%) such as frameshift codon 44 (-C) 0.7%, frameshift codons 74/75 (-C) 0.7%, IVS-1-5 (G-->C) 0.7%, frameshift codons 8/9 (+G) 0.4%, frameshift codons 36/37 (-T) 0.4%, frameshift codons 22/23/24 (-AAGTTGG) 0.4%, IVS-1-130 (G-->C) 0.4%, IVS-1-5 (G-->T) 0.2%, -28 (A-->C) 0.2%, codon 15 (TGG-->TGA) 0.2%, and frameshift codons 82/83 (-G) 0.2%, were detected by sequence analysis. The codon 15 (TGG-->TGA) and frameshift codons 82/83 (-G) mutations were seen in Turkey for the first time.