The frequency of factor V Leiden mutation,ACE gene polymorphism,serum ACE activity and response to ACE inhibitor and angiotensin II receptor antagonist drugs in Iranians type II diabetic patients with microalbuminuria

The aim of present study was to determine if factor V Leiden (FVL) mutation and angiotensin converting enzyme insertion/deletion (ACE I/D) polymorphism are associated with diabetic nephropathy (DN) among Kurdish population from Western Iran. This case–control study comprised 144 unrelated adult type 2 diabetic mellitus patients (T2DM) including 72 patients with microalbuminuria and 72 age and sex matched patients without nephropathy. The ACE I/D polymorphism and FVL mutation were detected by polymerase chain reaction (PCR) and PCR–RFLP, respectively. The frequency of FVL G1691A and ACE D allele in T2DM patients with microalbuminuria were 1.6 and 57%, respectively and in normoalbuminuric T2DM patients were 4.9 and 58.3%, respectively (P > 0.05). ACE genotypes affected on serum ACE activity and a better response to ACE inhibitor therapy (captopril) compared to angiotensin II receptor antagonist (losartan) was obtained with significant reduction of ACE activity in diabetic patients without nephropathy carrying DD genotype. However, the beneficial effect of losartan therapy was observed in microalbuminuric patients with II genotype compared to ID and DD genotypes.     

ACE gene polymorphism and cardiac structure in patients with insulin resistance

Aims: Angiotensin-converting enzyme (ACE) is a key enzyme in the production of angiotensin II, thus may participate in the modulation of cardiac growth. The aim of our study is to analyze the ACE gene I/D polymorphisms in patients with insulin resistance (IR) and to evaluate its relationship to left ventricular mass and functions. Methods: Eighteen subjects (13 female and 5 male, mean age 39.8 ± 14) with IR were enrolled in the present study. Twenty-three healthy people without IR were recruited as the control group. ACE amplification of DNA was performed by polymerase chain reaction methodology. Fasting glucose and insulin, postprandial glucose, homeostasis model assessment (HOMA-IR) and HOMA-beta, lipid profile, anthropometric measurements were assessed. Left ventricular structure and functions were measured by echocardiography. Results: Distribution of I/D polymorphism of the ACE gene in the study group was as follows: genotype II–0%, ID–38.9%, DD–61.1% of patients. Distribution of individual genotypes was similar in patients with and without IR. No significant difference was found between genotype groups in terms of anthropometric measurements and metabolic parameters and blood pressure. Echocardiography showed no significant changes in left ventricular structure and functions in patients with IR. Conclusions: We considered that in patients with IR, there is no relationship between I/D polymorphism of the ACE gene and LVH.     

A polymorphism in the cyclooxygenase 2 gene in type 1 diabetic patients with nephropathy

Diabetic nephropathy (DN), the most serious complication of Type 1 diabetes (DM1), has a strong genetic component. Cyclooxygenase-2 (COX-2), an inducible enzyme by a number of stimuli, has been implicated in pathophysiology of cardiovascular and renal disease, including DN. The allele -765C, of the -765G > C polymorphism (rs20417) in the COX-2 promoter has lower promoter activity compared with the -765G allele and protective effects in cardiovascular disease. This polymorphism was not investigated in patients with DM1 and nephropathy. The study was conducted in 779 Caucasian patients with DM1 and compared to a representative sample of healthy Czech population. The patients demonstrated lower frequencies of the CC genotype (P = 0.005). From the DM1 cohort, 153 patients met the criteria for low risk of the development of DN (LRDN, duration of DM1 > 10 years, normoalbuminuria, normotension) and 139 patients had manifest DN. There were no differences in -765G > C polymorphisms between LRDN and DN patients. Moreover, the C/G allele frequencies did not also differ between the groups. In conclusion, patients with DM1 display lower freqencies of the protective CC genotype as compared to healthy subjects. However, the study did not reveal associations of -765G > C polymorphism with the risk of DN.     

Lack of association between an ecNOS gene polymorphism and diabetic nephropathy in type 2 diabetic patients with proliferative diabetic retinopathy.

The development of diabetic nephropathy shows remarkable variation among individuals. Therefore, not only hyperglycemia but also genetic factors may contribute to the development of diabetic nephropathy. The aim of the present study was to examine the contribution of the 27-bp repeat polymorphism in intron 4 of the endothelial constitutive nitric oxide synthase gene (ecNOS4) to the development of diabetic nephropathy. For this purpose, we analyzed this polymorphism in 167 Japanese type 2 diabetic patients with proliferative diabetic retinopathy consisting of 102 patients with diabetic nephropathy (with macroalbuminuria) and 65 patients without diabetic nephropathy (with normoalbuminuria). The genotype and allele frequencies were not significantly different between patients with diabetic nephropathy and those without diabetic nephropathy (ecNOS4 "b/b" 79.4% vs. 84.6%, ecNOS4 "b/a" 20.6% vs. 15.4%, "b" allele 89.7% vs. 92.3%, "a" allele 10.3% vs. 7.7%). We conclude that the ecNOS4 polymorphism does not contribute to the development of diabetic nephropathy.     

Association of soluble epoxide hydrolase gene polymorphism with insulin resistance in type 2 diabetic patients

The insulin resistance found in diabetes is influenced by vascular tone and local blood flow. Endothelial-derived hyperpolarizing factor (EDHF) functions as a potent vasodilator to regulate vascular tone, and its production is regulated by soluble epoxide hydrolase (sEH). In this study, we examined the genotype distribution and allele frequency of sEH gene G860A (Arg287Gln) polymorphism in Japanese subjects (n=499) (non-diabetic subjects, n=205; type 2 diabetic patients, n=294). Also, to accurately evaluate insulin resistance, we performed the euglycemic hyperinsulinemic clamp test for each type 2 diabetic patient (n=86) from whom agreement was obtained, and then examined a possible association of sEH gene G860A polymorphism with insulin resistance status. There was no significant difference in genotype distribution and allele frequency between non-diabetic subjects and type 2 diabetic patients. Interestingly, however, there was close association of sEH gene G860A (Arg287Gln) polymorphism with insulin resistance in type 2 diabetic patients, which was not observed in non-diabetic subjects. These results suggest that sEH and EDHF play some important role in the pathogenesis of insulin resistance found in type 2 diabetes.     

Q192R polymorphism of PON-1 gene in type 2 diabetic patients

Polymorphism of PON-1 gene in 192 position of amino acid sequence of enzyme paraoxonase 1 was studied. For this research we have used the blood samples of 96 patients with T2DM and 123 healthy habitants of Kharkiv. Frequencies of alleles for the patients (pQ = 0,65, pR = 0,35) and the healthies (PQ = 0,70 and pR = 0,30) did not differentiate meaningfully. Distribution of the genotypes for healthy people does not correspond to Hardy-Weinberg equilibrium, the patients of T2DM have surplus of both homozygotes and shortage of heterozygotes. The risk of illness of T2DM for QQ homozygotes is 1,46-times higher and for QR heterozygotes is two times lower than on the average in the population (2%). The risk of illness of T2DM for RR homozygotes 1,86-times exceeds a middle population risk but is not significant.     

Uncoupling protein 2 G(-866)A polymorphism: a new gene polymorphism associated with C-reactive protein in type 2 diabetic patients C-reactive protein in type 2 diabetic patients

Objective

To evaluate glycemic variability associated with two different premixed insulin analogue formulations when used in a twice-daily regimen.

Patients and Methods

Subjects comprised type 2 diabetic patients aged 20-79 years, treated with twice daily premixed insulin or insulin analogue formulations. All subjects were hospitalized for 6 days and randomized to receive either Humalog Mix 25 (Mix 25) or Humalog Mix 50 (Mix 50). They were then crossed over to the other arm between day 3 and day 4 of the study. Continuous glucose monitoring (CGM) was performed on all subjects to examine the differences in glycemic variability.

Results

Eleven type 2 diabetic patients were enrolled. No significant difference was found in 24-hour mean glucose values and their SDs, pre-meal glucose values, increases from pre-meal to peak glucose values, or time to peak glucose levels between either group. However, the mean glucose values observed during 0-8 hrs were significantly lower with Mix 25 compared to Mix 50 (128 vs. 147 mg/dL; p = 0.024).

Conclusions

The twice-daily Mix 25 regimen provided superior overnight glycemic control compared to the Mix 50 regimen in Japanese patients with type 2 diabetes. However, both twice-daily regimens with either Mix 25 or Mix 50 provided inadequate post-lunch glycemic control.

Trial Registration

Current Controlled Trials UMIN000001327     

Frequency of angiotensin II type 1 receptor gene polymorphism in Turkish acute stroke patients

This study was performed in acute stroke patients in the Turkish population to determine the frequency of the A1166C polymorphism in the AT1 gene and to examine the role of this polymorphism in acute stroke development. In this study, 257 genomic DNA samples were analysed (from 206 acute stroke patients and 51 healthy individuals). Genomic DNA was prepared from peripheral blood using the salt‐extraction method. The presence of the A1166C polymorphism in the AT1 gene was determined using the polymerase chain reaction (PCR)‐restriction fragment length polymorphism (RFLP) method. PCR products were separated by 2% agarose gel electrophoresis and visualized by a charge‐coupled device (CCD) camera. In this study, the allele frequency at the A1166C position was 92% A and 8% C for control and 97% A and 3% C for patients. This difference in allele frequency between the control group and the patient group was not statistically significant. However, genotype and allele frequencies showed a significant difference (P < 0.001) in the control and the patient groups. The results of this study show no relationship between the A1166C polymorphism in the AT1 gene and acute stroke in the Turkish population.     

ACE gene polymorphism in peripheral vascular disease.

Peripheral vascular disease is an atherosclerotic process. It has been suggested that angiotensin converting enzyme insertion/deletion polymorphism is associated with atherosclerosis. The aim of this study was to investigate the role of the insertion/deletion polymorphism of the angiotensin-converting enzyme in Turkish patients with peripheral vascular disease in Western part of Turkey. We also investigated the relationship between serum angiotensin converting enzyme activity and distribution of genotypes in both patients and control group. The study group consisted of 78 patients with peripheral vascular disease. The control group consisted of 73 healthy adults. Serum angiotensin converting enzyme activities in patients were higher than those of the control group (p<0.05). Angiotensin converting enzyme genotype frequencies in patients were observed as 28.2%, 18% and 53.8% for DD, II and ID polymorphism, respectively. These frequencies in controls were 42.5%, 20.5% and 37% for DD, II and ID, respectively. Serum angiotensin converting enzyme activities in both groups with II genotype were significantly lower than those with ID and DD genotype (p<0.05). Although conflicting results have been reported about this polymorphism in patients with peripheral vascular disease, we suggest that the angiotensin converting enzyme ID genotype may be a risk factor for peripheral vascular disease.     

Association between I/D polymorphism in the ACE gene and sarcoidosis in Turkish patients

Sarcoidosis is a chronic inflammatory disease with a complex pathogenesis and unknown etiology characterized by noncaseating granulomas that invade the lungs, eyes, liver and other organs. Insertion (I)/deletion (D) polymorphism in the gene encoding the angiotensin-converting enzyme (ACE) has been studied to examine the genetic predisposition to sarcoidosis in different populations, but the results have been inconsistent and inconclusive. This study aimed to determine the frequencies of the genotypes and alleles of I/D polymorphism in the ACE gene in Turkish patients as a distinct ethnic group and to investigate whether such polymorphism is associated with predisposition to sarcoidosis. Genomic DNA samples obtained from 154 individuals (70 patients with sarcoidosis and 84 healthy controls) were used in the study. The DNA was amplified using polymerase chain reactions using allele-specific primers. The amplified products were analyzed by 2 % agarose gel electrophoresis followed by UV transillumination. The allele frequencies and genotype distribution of the groups were analyzed using the Chi square test. There were no significant differences between the controls and sarcoidosis cases with respect to genotype distribution (χ² = 4.202, p = 0.122) and allele frequencies (χ² = 1.358, p = 0.244). Our results suggest that I/D polymorphism in the ACE gene does not cause a genetic predisposition to sarcoidosis in Turkish patients.     

VEGF gene polymorphism association with diabetic neuropathy

Vascular factors beside metabolic problems are involved in both etiopathogenesis of diabetic neuropathy, and more remarkably, later in “repair” phase, that governs the net balance between neuro-regenerative/degenerative reactions. Regarding ischemic nature of diabetic neuropathy that highlights necessity of blood vessels re-establishment during tissue healing, VEGF (vascular endothelial growth factor) has been recently the subject of extensive investigations in diabetic neuropathy (DNU). This growth factor possesses angiogenic potentials in addition to the hemodynamic functions. The distribution of VEGF gene polymorphisms at positions −7*C/T, −1001*G/C, −1154*G/A and −2578*C/A were analysed by ARMS–PCR in 248 type 1 diabetic British-Caucasian subjects (81 DNU+, 167 DNU−). We have found that distribution of a VEGF gene polymorphism at promoter region (−7*C/T) was significantly different between diabetic subjects with vs. without neuropathy and the allele (C) conferred susceptibility to DNU (P = 0.02; OR = 1.78, 95% CI 1.0–3.1). The present study indicates that polymorphism of the VEGF gene at position −7*C/T might be implicated in the pathogenesis of diabetic neuropathy as it may harbour some functional/regulatory potential in VEGF gene expression. However, this requires further studies in order to better understand its phenotypic impact and to investigate the prognostic value of this polymorphism in diabetic neuropathy as a chronic complication of diabetes.     

High dose Losartan and ACE gene polymorphism in IgA nephritis

Background/aims Several studies have reported varying results of the influence of ACE gene on ACEI/ARB therapy. The efficacy of high dose ARB and its influence on ACE gene have not been explored. This is a 6 year randomised trial in IgA nephritis comparing high dose ARB (Losartan 200 mg/day) with normal dose ARB (Losartan 100 mg/day), normal dose ACEI (20 mg/day) and low dose ACEI (10 mg/day). Results Patients on high dose ARB had significantly lower proteinuria, 1.0 ± 0.8 gm/day compared to 1.7 ± 1.0 g/day in the other groups (P = 0.0005). The loss in eGFR was 0.7 ml min^?1year^?1 for high dose ARB compared to 3.2–3.5 ml min^?1year^?1 for the other three groups (P = 0.0005). There were more patients on high dose ARB with improvement in eGFR compared to other three groups (P < 0.001). Comparing patients with the three ACE genotypes DD, ID and II, all three groups responded well to therapy with decrease in proteinuria (P < 0.002). Only those on low dose ACEI (10 mg/day) with the I allele had increased in ESRF (P = 0.037). Conclusion High dose ARB is more efficacious in reducing proteinuria and preserving renal function when compared with normal dose ARB and ACEI, and also obviates the genomic influence of ACE gene polymorphism on renal survival.     

Angiotensin converting enzyme (ACE) activity levels in insulin-independent diabetes mellitus and effect of ACE levels on diabetic patients with nephropathy

Involvement of complications is considered to be one of the major factors in the prognosis of diabetes mellitus (DM). Recent studies indicate that most diabetic complications such as nephropathy and hypertension are vascular-originated. Renin-angiotensin involvement, especially changes in ACE activity level, is considered to be a key factor since ACE converts angiotensin I to angiotensin II which is a potent vasoconstrictor and plays a vital role in the regulation of blood pressure. Our present study focused on ACE activity levels along with blood glucose and HbA(1c) levels in diabetic patients with (n=18) or without (n=25) nephropathy as compared to control subjects (n=25). Blood glucose levels were significantly higher in both diabetic groups compared to controls (p<0.001). On the other hand, compared to controls, blood HbA(1c) levels were slightly higher in DM patients without complications whereas they were significantly increased in nephropatic DM patients (p<0.001). There was a very strong increase (p<0.001) at the level of ACE activity in both of the diabetic groups (with nephropathy: 47.11+/-3.70 U l(-1); without complications: 43.72+/-2.93 U l(-1); controls: 25.15+/-2.30 U l(-1)). ACE activity levels were also significantly higher in diabetic patients with nephropathy than in type II DM patients without complication (p<0.01). Our results demonstrate that ACE activity levels are increased in diabetic patients. Additional significant increase in ACE activity levels in diabetic patients with complications such as nephropathy supports the hypothesis that ACE activity has an essential role in the development of complications in diabetes.     

E-selectin-inducing activity in plasma from type 2 diabetic patients with maculopathy

Diabetic maculopathy (DMa) is a leading cause of visual loss in the western world. We examined whether plasma from type 2 diabetic patients with DMa contains factor(s) capable of inducing expression of the adhesion molecules E-selectin and VCAM-1 or cellular proliferation in cultured endothelial cells. Four gender-, age-, and duration (diabetes groups)-matched groups of 20 subjects each participated: 1) subjects with normal glucose tolerance (NGT), 2) subjects with impaired glucose tolerance (IGT), 3) type 2 diabetic patients without retinopathy, and 4) type 2 diabetic patients with DMa. Fasting plasma was added to in vitro-grown human umbilical vein endothelial cells for 6 h, after which E-selectin and VCAM-1 expression was measured. Proliferation was evaluated by thymidine incorporation. The individuals were characterized by measurement of 24-h ambulatory blood pressure, urinary albumin excretion rate, Hb A(1c), and blood lipids. Plasma from type 2 diabetic patients with DMa induced a significantly higher expression of E-selectin in endothelial cells than did plasma from subjects with NGT (259 +/- 23 x 10(3) vs. 198 +/- 19 x 10(3); arbitrary absorbance units; P < 0.05). There were no significant differences in plasma stimulatory effects on VCAM-1 expression or on thymidine incorporation between groups. These findings suggest that plasma from type 2 diabetic patients with DMa contains factor(s) capable of inducing the expression of E-selectin in endothelial cells. Enhanced expression of E-selectin may contribute to the development of DMa in type 2 diabetes.     

Balneotherapy and platelet glutathione metabolism in type II diabetic patients

Effects of balneotherapy on platelet glutathione metabolism were investigated in 12 type II (non-insulin-dependent) diabetic patients. Levels of the reduced form of glutathione (GSH) on admission were well correlated with those of fasting plasma glucose (FPG;r=0.692,P<0.02). After 4 weeks of balneotherapy, the mean level of GSH showed no changes; however, in well-controlled patients (FPG <150 mg/dl), the level increased (P<0.01) and in poorly controlled patients (FPG >150 mg/dl), the value decreased (P<0.05). There was a negative correlation between glutathione peroxidase (GPX) activities and the levels of FPG (r=–0.430,P<0.05). After balneotherapy, the activity increased in 5 patients, decreased in 3 patients and showed no changes (alteration within ±3%) in all the other patients. From these findings in diabetic patients we concluded: (1) platelet GSH synthesis appeared to be induced in response to oxidative stress; (2) lowered GPX activities indicated that the antioxidative defense system was impaired; and (3) platelet glutathione metabolism was partially improved by 4 weeks balneotherapy, an effect thought to be dependent on the control status of plasma glucose levels. It is suggested that balneotherapy is beneficial for patients whose platelet antioxidative defense system is damaged, such as those with diabetes mellitus and coronary heart disease.     

The ACE polymorphism is associated with BMI in patients with metabolic syndrome

The angiotensin-converting enzyme (ACE) polymorphism is well known to be associated with cardiovascular diseases. Until now, however, evidence for the role of ACE polymorphism in susceptibility to metabolic syndrome (MS) has not been well studied. Thus, we investigated an association between ACE polymorphisms and Korean patients with MS. DNA samples from 214 MS patients and 193 age-matched non-MS subjects were amplified using the polymerase chain reaction for detection of the ACE insertion/deletion (I/D) and BstUI polymorphisms. Anthropometric and physiological parameters including body mass index (BMI), waist circumference, blood pressure, glucose, triglycerides, total cholesterol and HDL cholesterol were measured. The genotype frequencies of the ACE I/D and BstUI polymorphisms were not significantly different between the non-MS and the MS group. The BB genotype distribution of the BstUI polymorphism in the female subgroup, however, was associated with an increased risk of MS (P = 0.008). When the data were stratified by BMI values, the high BMI groups showed significant differences between the non-MS and the MS groups, compared to the low BMI group, in all genotype frequencies of the ACE I/D and BstUI polymorphisms. The trend remained even when the genotypes of the two polymorphisms were combined. Although no consistent results were obtained on the association between the ACE polymorphism and MS in the populations studied, the ACE polymorphism, at least in Koreans, may be a genetic determinant of BMI in MS patients. Therefore, further studies are required on the association between the ACE polymorphism and MS patients in other racial or ethnic groups.     

Angiotensin II type 1 receptor gene polymorphism and telomere shortening in essential hypertension

Several genetic studies were carried out among hypertensive patients to assess allelic association at the 1166 position of the 3' untranslated region of angiotensin II type 1 receptor gene. In addition, attempts have also been made to find out whether telomere length attrition is associated with hypertension. The main aim of this study was to examine the association of A1166C polymorphism of angiotensin II type 1 receptor and telomere length with essential hypertension in Egyptian people. Angiotensin II type 1 genotyping and relative telomere length were investigated by PCR in 40 patients of essential hypertension and 15 healthy controls. The homozygous AA1166 allele frequency was 92.8% among the studied subjects. There was no intergroup variation in A allele frequency in normotensive group. The frequency of homozygous A allele was significantly higher in hypertensive than normotensive subjects (97.5 and 80%, respectively) with higher frequencies in male patients. The average telomere length ratio was significantly shorter in hypertensive than in normal subjects (1.08?±?0.3 and 1.54?±?0.18, respectively). No correlation was observed between telomere length ratio and body mass index. This study suggests that the homozygous A1166 allele of angiotensin II type 1 and short telomeres may be predisposing factors for essential hypertension in Egyptians and may be involved in the pathogenesis of the disease. Further strategies for treating high-risk patients could result in prevention or delay of end organ damage.