Angiotensin I converting enzyme gene polymorphism in non-insulin dependent diabetes mellitus

Angiotensin-converting enzyme I/D gene polymorphism and risk of type 2 diabetes mellitus in Iranian individuals

This study aimed to examine the relationship between type 2 diabetes mellitus (T2DM) and renin-angiotensin system gene polymorphisms in the Iranian population. Additionally, we performed a straightforward meta-analysis of the present articles to better understand this role. A total of 100 Iranian individuals, 50 patients with T2DM, and 50 age-matched healthy individuals were included in this study. DNA was extracted using the salting-out approach, polymerase chain reaction was used to amplify the angiotensin-converting enzyme (ACE) gene, electrophoresis techniques were used, and genotyping was performed. We also searched PubMed, Web of Science, Scopus, and Google Scholar databases for papers published in 2023. We found a significantly higher frequency of I/D genotype in the patient group than in the control group, and the risk of T2DM was 10 times higher in individuals with the I/D genotype (OR, 10 [95% CI, 3.7 to 27]; p < 0.0001) and also 2.85 time higher in individuals with the D allele OR, 2.85 [95% CI, 1.55 to 5.24]; p < 0.001). The ACE polymorphism alleles D and I/D genotypes may increase the risk of developing T2DM in an Iranian population.

Relationship between insertion/deletion (I/D) polymorphism of angiotensin converting enzyme (ACE) gene and susceptibility to type 2 diabetes mellitus in the Middle East and North Africa Region: A meta-analysis

BACKGROUND AND AIMS

The association between insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene and the risk of type 2 diabetes mellitus (T2DM) remains controversial. This study aimed to assess the effect of the ACE I/D gene polymorphism on T2DM in the Middle East and North Africa region (MENA region).

MATERIAL AND METHODS

Our data was extracted from PubMed, Science Direct, and the Web of Science. The predefined inclusion criteria included only the human case-control studies of English Peer-reviewed papers containing the data on genotype distributions of ACE I/D polymorphism and the T2DM risk. Review articles, meeting abstracts, editorials, animal studies, and studies not providing genotype distribution data or without sufficient data were excluded from this work. Results of this meta-analysis were expressed using odds ratios (OR) and 95% confidence intervals (CI). Indeed, the potential sources of heterogeneity and bias were examined by the Egger regression.

RESULTS

Of 2755 identified articles, 10 studies were selected, including 2710 patients with T2DM and 2504 control subjects. Overall, we found a significant increased risk of T2DM susceptibility and the D allele of ACE I/D gene polymorphism (OR = 1.97; 95% CI = 1.33-2.93, p = 0.0007), recessive (OR = 2.16; 95% CI = 1.27-3.67; p = 0.004), dominant (OR = 2.45; 95% CI = 1.54-3.91; p = 0.0001), homozygote (OR = 3.35; 95% CI = 1.78-6.29; p = 0.0001) and heterozygote comparisons (OR = 1.76; 95% CI = 1.07-2.88; p = 0.024).

CONCLUSION

Our result suggests that this polymorphism may contribute to the development of T2DM in the MENA Region. This result needs to be confirmed by future well-designed studies with larger sample sizes in diverse populations and ethnicities.

Lack of relationship between Alu repetitive elements in angiotensin converting enzyme and the severity of diabetic retinopathy

Background

Angiotensin-converting enzyme (ACE) stimulates angiogenesis that leads to the development of diabetic retinopathy (DR). Alu repetitive elements in ACE gene increase the expression of this enzyme. We investigated the frequency of Alu repetitive elements, insertion/deletion (I/D) polymorphism, in angiotensin-converting enzyme among diabetic retinopathy patients and whether this polymorphism is associated with the severity of retinopathy in Jordanians with type 2 diabetes.

Methods

A total of 277 subjects participated in this case/ control study (100 diabetic patients without DR, 82 diabetic patients with DR, and 95 healthy control). Blood samples were withdrawn, followed by DNA extraction. Alu repetitive elements were examined by polymerase chain reaction followed by gel electrophoresis.

Results

The genotype and allele frequencies among diabetic patients, were close to healthy controls (genotypes, II 44.4 vs. 44.7%, ID 44.4 vs. 42.6%, DD 12.2 vs. 12.8%, P = 0.402 and 0.677 respectively, alleles, I 65.6 vs. 66%, D 34.4 vs. 34%, P=0.863). Complicated diabetics with retinopathy showed similar genotype and allele frequency to those without complications. The severity of diabetic retinopathy in affected individuals was not correlated with I/D polymorphism (P=0.862).

Conclusions

We conclude that the presence of Alu repetitive elements did not increase the development or progression risk to retinopathy in Jordanian type 2 diabetic patients. No association between I or D alleles with the severity of DR was detected.

Angiotensin converting enzyme: A review on expression profile and its association with human disorders with special focus on SARS-CoV-2 infection

Angiotensin-converting enzyme (ACE) and its homologue, ACE2, have been mostly associated with hypertensive disorder. However, recent pandemia of SARS-CoV-2 has put these proteins at the center of attention, as this virus has been shown to exploit ACE2 protein to enter cells. Clear difference in the response of affected patients to this virus has urged researchers to find the molecular basis and pathophysiology of the cell response to this virus. Different levels of expression and function of ACE proteins, underlying disorders, consumption of certain medications and the existence of certain genomic variants within ACE genes are possible explanations for the observed difference in the response of individuals to the SARS-CoV-2 infection. In the current review, we discuss the putative mechanisms for this observation.

Renin-Angiotensin-Aldosterone System Gene Polymorphisms and Type 2 Diabetic Nephropathy in Asian Populations: An Updated Meta-analysis

BACKGROUND

The association of polymorphisms in the renin-angiotensin-aldosterone system candidate genes, namely Angiotensin-Converting Enzyme (ACE) Insertion/Deletion (I/D), Angiotensinogen (AGT) M235T and Angiotensin II Receptor Type 1 (AGTR1) A1166C with Diabetic Nephropathy (DN) has been studied for decades.

OBJECTIVE

This meta-analysis aimed to assess the updated pooled effects of these polymorphisms with DN among Asian populations with type 2 diabetes mellitus.

METHODS

The PubMed electronic database was searched without duration filter until August 2017 and the reference list of eligible studies was screened. The association of each polymorphism with DN was examined using odds ratio and its 95% confidence interval based on dominant, recessive and allele models. Subgroup analyses were conducted based on region, DN definition and DM duration.

RESULTS

In the main analysis, the ACE I/D (all models) and AGTR1 A1166C (dominant model) showed a significant association with DN. The main analysis of the AGT M235T polymorphism did not yield significant findings. There were significant subgroup differences and indication of significantly higher odds for DN in terms of DM duration (≥10 years) for ACE I/D (all models), AGT M235T (recessive and allele models) and AGTR1 A1166C (recessive model). Significant subgroup differences were also observed for DN definition (advanced DN group) and region (South Asia) for AGTR1 A1166C (recessive model).

CONCLUSION

In the Asian populations, ACE I/D and AGTR1 A1166C may contribute to DN susceptibility in patients with T2DM by different genetic models. However, the role of AGT M235T needs to be further evaluated.

Association between the Angiotensin-Converting Enzyme (ACE) Genetic Polymorphism and Diabetic Retinopathy-A Meta-Analysis Comprising 10,168 Subjects

Aims-to address the inconclusive findings of the association of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism on risk of diabetic retinopathy (DR), a meta-analysis was conducted. Methods-we conducted a meta-analysis on 4252 DR cases and 5916 controls from 40 published studies by searching electronic databases and reference lists of relevant articles. A random-effects or fixed-effects model was used to estimate the overall and stratification effect sizes on ACE I/D polymorphism on the risk of DR. Results-we found a significant association between the ACE I/D polymorphism and the risk of DR for all genetic model (ID vs. II: OR = 1.14, 95% CI: 1.00-1.30; DD vs. II: OR = 1.38, 95% CI: 1.11-1.71; Allele contrast: OR = 1.17, 95% CI: 1.05-1.30; recessive model: OR = 1.24, 95% CI: 1.02-1.51 and dominant model: OR = 1.21, 95% CI: 1.06-1.38, respectively). In stratified analysis by ethnicity and DM type, we further found that the Asian group with T2DM showed a significant association for all genetic models (ID vs. II: OR = 1.14, 95% CI: 1.01-1.30; DD vs. II: OR = 1.54, 95% CI: 1.14-2.08; Allele contrast: OR = 1.26, 95% CI: 1.09-1.47; recessive model: OR = 1.42, 95% CI: 1.07-1.88 and dominant model: OR = 1.26, 95% CI: 1.07-1.49, respectively). Conclusion-our study suggested that the ACE I/D polymorphism may contribute to DR development, especially in the Asian group with type 2 diabetes mellitus (T2DM). Prospective and more genome-wide association studies (GWAS) are needed to clarify the real role of the ACE gene in determining susceptibility to DR.

The angiotensin-I converting enzyme gene I/D variation contributes to end-stage renal disease risk in Chinese patients with type 2 diabetes receiving hemodialysis

Whether the DD genotype of the angiotensin-I converting enzyme (ACE) I/D variation contributes to end-stage renal disease (ESRD) risk in type 2 diabetes mellitus (T2DM) remains controversial. Differences in study design, case and control definition, sample size and ethnicity may contribute to the discrepancies reported in association studies. We performed a case-control study to evaluate the association of the ACE I/D variation with ESRD risk in Chinese patients with T2DM receiving hemodialysis and analyzed the genotype-phenotype interaction. Unrelated Chinese patients (n = 432) were classified into the non-diabetic nephropathy (DN) control group (n = 222, duration of diabetes >10 years, no signs of renal involvement) and the DN-ESRD group (n = 210; ESRD due to T2DM, receiving hemodialysis). Polymerase chain reaction was used to genotype ACE I/D for all 432 subjects. The frequencies of the ID + DD genotypes were higher in the DN-ESRD group than non-DN control group (65.2 vs. 50.9 %; adjusted OR 1.98 (95 % CI, 1.31-3.00; P = 0.001). In the DN-ESRD group, the DD genotypic subgroup had significantly elevated HbA1c and diastolic blood pressure (DBP) compared to the II subgroup (both P < 0.05). The DD genotype of the ACE I/D variation may be associated with more elevated blood pressure and HbA1c, and therefore may predict the development, progression and severity of DN-ESRD in Chinese patients with T2DM undergoing hemodialysis.

Inhibition of RAS in diabetic nephropathy

Diabetic kidney disease (DKD) is a progressive proteinuric renal disorder in patients with type 1 or type 2 diabetes mellitus. It is a common cause of end-stage kidney disease worldwide, particularly in developed countries. Therapeutic targeting of the renin-angiotensin system (RAS) is the most validated clinical strategy for slowing disease progression. DKD is paradoxically a low systematic renin state with an increased intrarenal RAS activity implicated in its pathogenesis. Angiotensin II (AngII), the main peptide of RAS, is not only a vasoactive peptide but functions as a growth factor, activating interstitial fibroblasts and mesangial and tubular cells, while promoting the synthesis of extracellular matrix proteins. AngII also promotes podocyte injury through increased calcium influx and the generation of reactive oxygen species. Blockade of the RAS using either angiotensin converting enzyme inhibitors, or angiotensin receptor blockers can attenuate progressive glomerulosclerosis in animal models, and slows disease progression in humans with DKD. In this review, we summarize the role of intrarenal RAS activation in the pathogenesis and progression of DKD and the rationale for RAS inhibition in this population.

M235T polymorphism in the AGT gene and A/G(I8-83) substitution in the REN gene correlate with end-stage renal disease

BACKGROUND/AIMS

This study aimed at investigating if M235T polymorphism in the AGT gene and A/G(I8-83) polymorphism in the REN gene correlate with end-stage renal disease (ESRD).

METHODS

We analyzed 173 ESRD patients and 329 individuals with normal kidney function for differences in the genotype distribution of AGT-M235T and REN-A/G(I8-83) polymorphisms between the two groups. The data for cases and controls were compared using the χ(2) test.

RESULTS

We found significantly higher levels of serum creatinine and CRP in cases in comparison to controls (p < 0.0001). Data comparison showed a significant association of AGT M235T substitution with ESRD in the dominant model (p = 0.008) and in the comparison of the heterozygous substitution with the homozygous common genotype (p = 0.005). Similarly, REN A/G(I8-83) polymorphism showed a significant difference in the distribution of genotypes between cases and controls (p < 0.038) such that a heterozygous substitution was significantly more common in the ESRD cases in comparison to the homozygous common genotype (p = 0.023).

CONCLUSION

We conclude that heterozygous substitutions at the AGT M235T and REN A/G(I8-83) loci correlate significantly with ESRD in a north Indian population.

Interaction between angiotensin-converting enzyme gene insertion/deletion polymorphism and angiotensin-converting enzyme inhibition on survival in hemodialyzed patients

The association between ACE (angiotensin-converting enzyme) gene insertion/deletion (I/D) polymorphism and mortality has been inconsistently observed in earlier studies in patients on maintenance hemodialysis. We hypothesized that the effect of ACE gene I/D polymorphism on mortality may be influenced by concurrent ACE inhibitor therapy in this population. In this prospective, multicenter cohort, observational study, data was collected from 716 prevalent chronic hemodialysis patients, blood samples were genotyped for I/D single nucleotide polymorphism. Patient mortality was assessed in tree genotype groups insertion/insertion, insertion/deletion and deletion/deletion (I/I, I/D, and D/D) using multivariate Cox proportional hazard models. The most frequent genotype was I/D (42.6%), followed by D/D (37.7%) and I/I (19.7%) genotypes. The mean age was 54.9±15.5 years, 53.2% of all patients were male and in the total group the prevalence of diabetes was 19.3%. ACE inhibitor therapy was prescribed for 47.9% of all patients. The median duration of dialysis before blood sampling was 23.8 months (IQR 11.2-47.1). Patients were followed for 10 years, the median follow-up time was 29.8 months (IQR 12.6-63.4). Patient characteristics were well balanced among the genotype groups. D/D genotype, was associated with inferior survival (I/I vs D/D: log-rank test: P=0.04) in patients not receiving ACE inhibitor therapy, and the presence of this therapy diminished this difference. There was no difference in survival among unselected patients with different genotypes. In multivariate Cox regression models, D/D genotype (compared to I/I) was a significant predictor of mortality only in patients without ACE inhibitor therapy (HR 0.67, 95% CI 0.46-0.97, P=0.03). Our data suggests that hemodialyzed patients with the deletion/deletion (D/D) genotype might have inferior outcome, and ACE inhibitor therapy may be associated with improved survival in this subgroup.

Susceptibility and progression of end stage renal disease are not associated with angiotensin II type 1 receptor gene polymorphism

CONTEXT

The role of the angiotensin II type 1 receptor (AT1R) gene polymorphism, A1166C, has been shown to be associated with end stage renal disease (ESRD) and its progression. There is also some evidence that HLA class II alleles are associated with ESRD independent of other factors.

OBJECTIVE

To examine the association between AT1R gene polymorphism in the susceptibility and progression to ESRD in patients with chronic renal failure and to investigate if the AT1R genotypes and HLA-DR alleles predict the time to ESRD.

MATERIALS AND METHODS

Genotyping was performed in 50 ESRD patients and 44 control subjects for the AT1R A1166C gene polymorphism using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). ESRD patients were examined for HLA-DRB1 alleles according to a reverse hybridization line probe assay.

RESULTS

Allele and genotype frequencies of the AT1R polymorphism did not differ significantly between ESRD patients and controls. Furthermore, there was no association between the AT1R gene polymorphism or HLA-DRB1 alleles with the time to the occurrence of end stage failure.

DISCUSSION AND CONCLUSION

We concluded that the AT1R genotype does not contribute to the genetic susceptibility of ESRD and is not associated with progression of chronic kidney failure to ESRD.

Angiotensin-converting enzyme I/D polymorphism and diabetic peripheral neuropathy in type 2 diabetes mellitus: A meta-analysis

BACKGROUND

Several molecular epidemiological studies have been conducted to examine the association between angiotensin-converting enzyme (ACE) I/D polymorphism and diabetic peripheral neuropathy (DPN) risk. However, the conclusions remained controversial. We therefore performed this meta-analysis.

METHODS

PubMed and EMBASE were searched to identify case-control studies investigating the associations of ACE I/D polymorphism with risk of DPN. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association between ACE I/D polymorphism and risk of DPN.

RESULTS

A total of seven case-control studies including 1316 cases and 1617 controls were included. ACE I/D polymorphism was associated with a significantly increased risk of DPN (OR=1.46, 95%CI 1.11-1.92, p=0.006, I(2)=48%). This result remained statistically significant when the adjusted ORs were combined (OR=1.84, 95%CI 1.14-2.99, p=0.01, I(2)=53%). In the subgroup of ethnicity, a significantly elevated risk was observed in Caucasians (OR=1.32, 95%CI 1.10-1.59, p=0.003, I(2)=43%).

CONCLUSIONS

Our meta-analysis confirmed that ACE I/D polymorphism was associated with the risk of DPN.

Survival and predictive factors of lethality in hemodialysis: D/I polymorphism of the angiotensin I-converting enzyme and of the angiotensinogen M235T genes

BACKGROUND

End-stage kidney disease patients continue to have markedly increased cardiovascular disease morbidity and mortality. Analysis of genetic factors connected with the renin-angiotensin system that influences the survival of the patients with end-stage kidney disease supports the ongoing search for improved outcomes.

OBJECTIVE

To assess survival and its association with the polymorphism of renin-angiotensin system genes: angiotensin I-converting enzyme insertion/deletion and angiotensinogen M235T in patients undergoing hemodialysis.

METHODS

Our study was designed to examine the role of renin-angiotensin system genes. It was an observational study. We analyzed 473 chronic hemodialysis patients in four dialysis units in the state of Rio de Janeiro. Survival rates were calculated by the Kaplan-Meier method and the differences between the curves were evaluated by Tarone-Ware, Peto-Prentice, and log rank tests. We also used logistic regression analysis and the multinomial model. A p value ≤ 0.05 was considered to be statistically significant. The local medical ethics committee gave their approval to this study.

RESULTS

The mean age of patients was 45.8 years old. The overall survival rate was 48% at 11 years. The major causes of death were cardiovascular diseases (34%) and infections (15%). Logistic regression analysis found statistical significance for the following variables: age (p = 0.000038), TT angiotensinogen (p = 0.08261), and family income greater than five times the minimum wage (p = 0.03089), the latter being a protective factor.

CONCLUSIONS

The survival of hemodialysis patients is likely to be influenced by the TT of the angiotensinogen M235T gene.

ACE insertion/deletion polymorphism and diabetic nephropathy: clinical implications of genetic information

Approximately 20-40% of diabetic patients develop nephropathy which is the leading cause of ESRD in developed countries. The ACE I/D polymorphism is thought to be a marker for functional polymorphism which regulates circulating and tissue ACE activity. While the initial study found a protective effect of the II genotype on the development of nephropathy in IDDM patients, subsequent studies have addressed the role of ACE I/D polymorphism in the development and progression of diabetic nephropathy. RAAS blockers are the first line drugs for the treatment hypertension associated with diabetes and have been widely used in everyday clinical practice for the purpose of reducing proteinuria in patients with various renal diseases. However, the antiproteinuric effect of RAAS blockers is variable and the percentage of reducing proteinuria is in the range of 20-80%. The antiproteinuric effect of RAAS blockers may be related to a number of factors: the type or the dose of RAAS blockers, the duration of therapy, the level of sodium intake, and the type of patient's ACE I/D genotype. Besides the nongenetic factors, drug responses, can be influenced by ACE gene polymorphism. In this review, we discuss the relationship between ACE I/D polymorphism and diabetic nephropathy and therapeutic response of RAAS blockers.

Association of genetic polymorphism of PPARγ-2, ACE, MTHFR, FABP-2 and FTO genes in risk prediction of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a non-autoimmune, complex, heterogeneous and polygenic metabolic disease condition characterized by persistent elevated blood glucose levels (hyperglycemia). India as said to be the diabetic capital of the world is likely to experience the largest increase in T2DM and a greater number of diabetic individuals in the world by the year 2030. Identification of specific genetic variations in a particular ethnic group has a critical role in understanding the risk of developing T2DM in a much efficient way in future. These genetic variations include numerous types of polymorphisms among which single nucleotide polymorphisms (SNPs) is the most frequent. SNPs are basically located within the regulatory elements of several gene sequences. There are scores of genes interacting with various environmental factors affecting various pathways and sometimes even the whole signalling network that cause diseases like T2DM. This review discusses the biomarkers for early risk prediction of T2DM. Such predictions could be used in order to understand the pathogenesis of T2DM and to better diagnostics, treatment, and eventually prevention.

Genetic predisposition for development of nephropathy in type 2 diabetes mellitus

The aim of the study was to explore the association of the angiotensin-converting enzyme (ACE) gene I/D polymorphism and the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism with development of diabetic nephropathy in type 2 diabetes mellitus. Three groups were recruited during 2007-2011: 232 normal controls, 185 type 2 diabetics without nephropathy, and 407 type 2 diabetics with nephropathy. The ACE I/D and MTHFR C677T polymorphisms were examined using PCR and PCR-RFLP methods. We found no significant association of the ACE I/D polymorphism with diabetic nephropathy in genotype, allele, dominant, and recessive models. We observed a significant association of MTHFR C677T with development of diabetic nephropathy in type 2 diabetics. The MTHFR C677T polymorphism plays a significant role in predisposition of renal insufficiency in diabetic patients.

Role of the ACE ID and PPARG P12A Polymorphisms in Genetic Susceptibility of Diabetic Nephropathy in a South Indian Population

BACKGROUND

Diabetic nephropathy (DN) is one of the life-threatening disorders characterized by persistent albuminuria, raised arterial blood pressure, a lowered glomerular filtration rate, and high risk of cardiovascular morbidity and mortality. The vascular genes ACE (Angiotensin-converting enzyme), and PPARG (peroxisome proliferator activated receptor gamma) are involved in alterations in vascular endothelium, and are suggested to play a role in the susceptibility of diabetic nephropathy.

OBJECTIVES

The aim of our study was to find out the role of ACE ID and PPARG P12A polymorphisms in genetic susceptibility of diabetic nephropathy in south Indian population.

PATIENTS AND METHODS

A total of 54 cases with diabetic nephropathy and 67 control subjects with diabetes were enrolled for our study. DNA was isolated from peripheral blood leucocytes, and genotyped using PCR-electrophoresis (ACE ID) or PCR-RFLP (PPARG P12A) methods.

RESULTS

ACE ID genotypes followed Hardy-Weinberg equilibrium in both cases and controls. But P12A genotypes deviated from Hardy-Weinberg equilibrium in diabetic controls. Chi(2) test was applied for the analysis of genotypic distributions in genotypic and dominant models. Odds ratios were also calculated. No significant differences in genotype frequencies of ACE ID and PPARG P12A polymorphisms were found on comparing patients with diabetic nephropathy with diabetic controls. The synergistic role of ACE ID* PPARG P12A interaction, did not show any association in patients with diabetic nephropathy when compared to diabetic controls.

CONCLUSIONS

In conclusion, the ACE and PPARG genes do not have a key role in conferring risk for diabetic nephropathy.

Meta-analysis of the relationship between ACE I/D gene polymorphism and end-stage renal disease in patients with diabetic nephropathy

AIMS

  Diabetic nephropathy (DN) is the major cause for end-stage renal disease (ESRD) and the pathogenesis for DN developing into ESRD is not clear at present. Results from published studies on the relationship between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and ESRD risk in DN patients are still conflicting. This meta-analysis was performed to evaluate the association between ACE I/D gene polymorphism and ESRD risk in DN patients.

METHODS

  Association studies were identified from the databases of PubMed, Embase and Cochrane Library on 1 October 2011, and eligible investigations were identified and synthesized using the meta-analysis method. Results were expressed using odds ratios (OR) for dichotomous data and 95% confidence intervals (CI) were also calculated.

RESULTS

  Twelve studies reporting the relation between ACE I/D gene polymorphism and ESRD risk in DN patients were identified. In overall populations, there was a notable association between D allele or DD genotype and ESRD susceptibility (D: OR = 1.32, 95% CI: 1.11-1.56, P = 0.002; DD: OR = 1.67, 95% CI: 1.25-2.21, P = 0.0004). In the sub-group analysis according to ethnicity, D allele or DD genotype was associated with ESRD risk in Asians. In Caucasians, the association of DD genotype with ESRD risk was observed, but the D allele was not. Furthermore, ACE I/D gene polymorphism was associated with ESRD risk in patients with DN due to diabetes mellitus type 2, but the association was not found for patients with DN due to diabetes mellitus type-1.

CONCLUSIONS

  Our results indicate that D allele or DD homozygous is associated with the ESRD susceptibility in DN patients. However, more investigations are required to further this association.

ACACβ gene (rs2268388) and AGTR1 gene (rs5186) polymorphism and the risk of nephropathy in Asian Indian patients with type 2 diabetes

Patients with type 2 diabetes (T2DM) are usually obese and concurrent obesity results into activation of the renin-angiotensin-system (RAS) which is a risk factor for diabetic nephropathy (DN). Gene-gene interaction between acetyl-coenzymeA carboxylase beta (ACACβ) gene, which is involved in fatty acid metabolism and angiotensin II receptors (AGTR1) gene, which mediates RAS proteins actions on renal tissue, polymorphism with DN have not been studied earlier. The present study was designed with the aim to examine the association of an ACACβ (rs2268388) and AGTR1 (rs5186) gene polymorphism with the risk of DN in Asian Indians. 1,158 patients with T2DM belonging to two independently ascertained North Indian and one South Indian cohorts were genotyped for ACACβ (rs2268388) and AGTR1 (rs5186) polymorphism using real time PCR-based Taq-man assay and PCR-RFLP assays. In all the three cohorts, a significantly higher frequency of T allele and TT genotypes of ACACβ and C allele and CC genotypes of AGTR1 were found in patients with DN as compared to patients without nephropathy. Further, T allele of ACACβ and C allele of AGTR1 were found to be significantly associated with proteinuria, a hallmark of DN. We also found significant epistatic interactions between these two genes. TT genotypes of ACACβ gene and CC genotype of AGTR1 gene confers the risk of DN and both genes had significant epistatic interaction in Asian Indian patients with T2DM.

Association of angiotensinogen M235T gene polymorphism with end-stage renal disease risk: a meta-analysis

Association between angiotensinogen (AGT) M235T gene polymorphism and end-stage renal disease (ESRD) risk is still controversial. This meta-analysis was performed to evaluate the association of AGT M235T gene polymorphism with ESRD susceptibility. A predefined literature search and selection of eligible relevant studies were performed to collect data from electronic databases of PubMed, Embase and Cochrane Library. Sixteen literatures were identified for the analysis of association of AGT M235T gene polymorphism with ESRD risk. T allele and TT genotype were associated with ESRD susceptibility in Caucasians (T: OR = 1.13, 95 % CI: 1.02-1.25, P = 0.02; TT: OR = 1.22, 95 % CI: 1.03-1.45, P = 0.02). However, MM genotype might not play a protective role against ESRD risk in Caucasians. Furthermore, there was no a markedly positive association between AGT M235T gene polymorphism and ESRD susceptibility in overall populations, Asians and Africans. In conclusion, T allele or TT homozygote is associated with the onset of ESRD in Caucasians. However, more studies should be performed in the future.

Association between genetic polymorphism of the angiotensin-converting enzyme and diabetic nephropathy: a meta-analysis comprising 26,580 subjects

Introduction: The effect of angiotensin-converting enzyme ( ACE) insertion/deletion (I/D) polymorphism on risk of diabetic nephropathy (DN) is still conflicting. The present meta-analysis was performed to evaluate the overall risk of this polymorphism associated with DN in different groups.

Materials and methods: A predefined search was performed on 14,108 DN cases and 12,472 controls from 63 published studies by searching electronic databases and reference lists of relevant articles.

Results: In this meta-analysis, we found a significant association between the ACE I/D polymorphism and the risk of DN for all genetic models (ID versus II: odds ratio [OR] = 1.12, 95% confidence interval [CI] 1.02–1.24; DD versus II: OR = 1.27, 95% CI 1.13–1.44; allele contrast: OR = 1.15, 95% CI 1.08–1.23; dominant model: OR = 1.18, 95% CI 1.07–1.31; and recessive model: OR = 1.18, 95% CI 1.08–1.30, respectively). In stratified analysis by ethnicity and DM type, we further found that the Asian group with type 2 diabetes mellitus (T2DM) showed a significant association for all genetic models (ID versus II: OR = 1.25, 95% CI 1.07–1.47; DD versus II: OR = 1.57, 95% CI 1.24–1.98; allele contrast: OR = 1.30, 95% CI 1.15–1.46; dominant model: OR = 1.37, 95% CI 1.10–1.69; and recessive model: OR = 1.34, 95% CI 1.15–1.56, respectively).

Conclusions: Our study suggested that the ACE I/D polymorphism may contribute to DN development, especially in the Asian group with T2DM.

Angiotensin converting enzyme gene polymorphism in type II diabetics with nephropathy

Nephropathy is an important and a frequent complication of long-term type II diabetic nephropathy. Strong evidence exists that genetic predisposition plays a major role in the development of diabetic nephropathy. Recent studies have implicated association between angiotensin converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and nephropathy. The deletion gene polymorphism of ACE gene has been shown to be associated with increased activity of this enzyme. This study examines the association of ACE I/D polymorphism with type II diabetes without nephropathy in 30 patients and type II diabetes with nephropathy in 30 patients. The results of the study suggest the association between the DD polymorphism and type II diabetes with nephropathy.

Management of hypertension in patients with diabetes mellitus

OBJECTIVE

To investigate the management of hypertension in patients with diabetes mellitus, living in a rural setting.

METHOD

A community health screening clinic was conducted at Charles Sturt University, Albury-Wodonga, in rural southeastern Australia. Patients with either diagnosed hypertension or high blood pressure who attended the clinic were eligible for inclusion in the present study. The awareness and control of hypertension was compared between patients with and without diabetes mellitus.

RESULTS

A total of 449 patients with hypertension were analyzed. One hundred twenty-one (26.9%) had hypertension and diabetes mellitus, and 328 (73.1%) had hypertension without diabetes mellitus. Hypertension awareness (61.2% versus 36.9%, P=0.014) and control (17.4% versus 7.0%, P=0.040) were significantly better in the hypertensive patients with diabetes mellitus than in the hypertensive patients without diabetes mellitus. Antihypertensive medication use was also significantly higher in patients with diabetes mellitus than in patients without diabetes mellitus (one antihypertensive medication, 41.3% versus 25.0%, P=0.045).

CONCLUSION

Awareness and control of hypertension were suboptimal in the patients in the present study. Diabetes mellitus, however, was associated with both higher awareness and better control of hypertension than having hypertension alone. This may be partially due to a higher use of antihypertensive medications by patients with diabetes mellitus.

Does angiotensin-converting enzyme polymorphism have association with symptomatic benign prostatic hyperplasia?

Objectives:

The aim of the study was to explore the putative significance of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and its correlation with the lower urinary tract symptoms (LUTS) in benign prostatic hyperplasia (BPH).

Materials and Methods:

ACE I/D polymorphisms were determined by polymerase chain reaction (PCR) in 200 patients with moderate to severe LUTS due to BPH and 200 patients of same age group without the LUTS having normal size prostate. ACE levels were estimated by spectrophotometer method. Logistic regression models were used to determine the genetic effects using SPSS statistical software (version 12.0).

Results and Conclusions:

The distribution of genotypes along with allelic frequency and carriage rate did not significantly differ between study and control groups. This study suggests that I/D polymorphisms within the ACE gene are not associated with the presence of LUTS in BPH patients. Future studies in large cohorts are needed that may reveal the spectrum of cellular mechanism mediated by ACE relevant to pathophysiology of BPH and effect of ethnic differences.

Renin-angiotensin-aldosterone system blockade and urinary albumin excretion in community-based patients with Type 2 diabetes: the Fremantle Diabetes Study

AIMS

To determine whether the reduction in urinary albumin excretion through renin-angiotensin-aldosterone system blockade found in intervention trials extends to community-based patients with Type 2 diabetes.

METHODS

We analysed data from 302 participants in the longitudinal observational Fremantle Diabetes Study who commenced angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy during follow-up and who had an annual assessment on either side of this therapeutic change.

RESULTS

At baseline, the patients had a mean age of 63.8 years, a median diabetes duration of 4 years, a median HbA(1c) of 7.6% (60 mmol/mol) and a geometric mean (sd range) urinary albumin:creatinine ratio of 3.3 mg/mmol (0.8-13.1 mg/mmol). The percentages with normo-, micro- and macroalbuminuria were 49.0, 38.4 and 12.6%, respectively. During 6.1 ± 1.7 years of follow-up, initiation of renin-angiotensin-aldosterone system blockade was associated with a larger geometric mean (sd range) absolute albumin:creatinine ratio reduction in the patients with macroalbuminuria compared with those who had either normo- or microalbuminuria [-40.9 (-825.7 to 159.9) mg/mmol) vs. 1.7 (-1.6 to 20.0) mg/mmol and -0.5 (-23.0 to 39.5) mg/mmol, respectively; P < 0.001]. These changes remained significant after adjustment for changes in blood pressure and other potentially confounding variables, including drug dose and angiotensin-converting enzyme genotype. The post-treatment median albumin:creatinine ratios were 35.4 and 27.4% lower than before treatment in those with micro- or macroalbuminuria, respectively.

CONCLUSIONS

Usual-care initiation of renin-angiotensin-aldosterone system blockade confers a quantitatively similar renal benefit to that in intervention trials in Type 2 diabetes.

Angiotensin-converting enzyme gene polymorphism is associated with proliferative diabetic retinopathy: a meta-analysis

The association of angiotensin-converting enzyme (ACE) gene polymorphism with diabetic retinopathy (DR) was investigated in many studies with conflicting results. To shed light on these inconclusive findings, a meta-analysis of all available studies relating I (insert)/D (delete) polymorphism to the risk of developing DR was conducted. This meta-analysis included genotype data on 2,342 cases with DR and 2,048 controls free of DR. Summary odds ratios were estimated. Potential sources of heterogeneity and bias were explored. Overall, in allelic genetic model, heterogeneity between studies was nonsignificant (P = 0.12). No publication bias was observed in the regression asymmetry test (τ = 0.84, P = 0.41). There was no significant association between this variant and DR. In additional analysis, the association of I/D variant with retinopathy was nonsignificant both in patients with type 1 diabetes (T1D) (1.01 [95% CI: 0.79-1.29]) and in patients with type 2 diabetes (T2D) (1.12 [95% CI: 0.93-1.35]). Significant association was not also observed between I/D variant and the background diabetic retinopathy (BDR). For the I/D polymorphism and its relationship to proliferative diabetic retinopathy (PDR), the dominant model showed nonsignificant heterogeneity among studies (P = 0.52; I (2) = 0%), and the fixed estimate pooled odd ratio (OR) JOP was significant, at 1.37 [95% CI: 1.02-1.84]. No association was observed between ACE I/D variant and DR, irrespective of the diabetic type. There was moderate evidence of its relationship to PDR, while its relationship to BDR was not found. Studies exploring the association between ACE I/D polymorphism and BDR or PDR may help us better understand the genetics of DR.

Progression of glomerular and tubular disease in pediatrics

Chronic kidney disease may be stimulated by many different etiologies, but its progression involves a common, yet complex, series of events that lead to the replacement of normal tissue with scar. These events include altered physiology within the kidney leading to abnormal hemodynamics, chronic hypoxia, inflammation, cellular dysfunction, and activation of fibrogenic biochemical pathways. The end result is the replacement of normal structures with extracellular matrix. Treatments presently are focused on delaying or preventing such progression, and are largely nonspecific. In pediatrics, such therapy is complicated further by pathophysiological issues that render children a unique population.

Association Between Activated Renin Angiotensin System and Bone Formation in Hemodialysis Patients: Is the Bone Mass Genetically Determined by ACE Gene Polymorphism?

BACKGROUND

Angiotensin II (ang II) receptor subtype I binding sites has been recently demonstrated on bone cell precursors. Ang II stimulates DNA and collagen synthesis in human adult bone cells. The aim of this study is to evaluate the role of renin angiotensin system in the bone metabolism and to address the genetic influence of angiotensin converting enzyme (ACE) gene polymorphism on bone mass in hemodialysis patients.

METHODS

Forty-eight end-stage renal disease patients (28 male, 20 female mean age 42+/-13 years,) on maintenance hemodialysis were included in the study. Bone mineral density (BMD) was estimated at lumbar spine and T score worse than -1.5 were considered as osteopenia. Serum parathyroid hormone (iPTH) and osteocalcin (OC), bone alkaline phosphatase (bAP) and carboxy terminal propeptide type 1 collagen (PICP) levels were measured as markers of bone metabolism. Plasma renin activity (PRA), serum ACE activity and ACE gene polymorphism (II, ID, DD) were determined.

RESULTS

Bone mineral density and T score of the hemodialysis patients were 0.92+/-0.17 g/cm2 and -1.36+/-1.50, respectively. Twenty-one patients (43,7%) were osteopenic (T score worse than -1.5) and mean T score of osteopenic patients was -2.72+/-0.72. T score of nonosteopenic group was -0.29+/-0.99. Serum calcium, serum, phosphorus, serum OC, serum bAP, serum PCIP, serum PTH levels were similar in osteopenics and nonosteopenics. No difference was observed in predialysis PRA and in both pre- and postdialysis serum ACE activity of patients in both groups. PRA after hemodialysis in nonosteopenic group was higher than osteopenics (p<0.05). Percent increment in PRA in hemodialysis patients was correlated with T score (R=0.48 p <0.05). Serum ACE activity was positively correlated with serum iPTH (R=0.29, p=0.02), serum OC (R=0.35, p=0.01), serum bAP (R=0.34, p=0.01), serum PCIP (R=0.36, p=0.01). T score (-0.7+/-1.5, vs -1.7+/-1.3 p <0.05) was higher in DD group (n=19) compared to II+ID group (n=29).

CONCLUSIONS

Association of biochemical and radiological signs of increased bone formation with activated RAS in hemodialysis patients might be an evidence for the involvement of this system in the regulation of bone metabolism.

Angiotensin converting enzyme insertion/deletion polymorphism and renoprotection in diabetic and nondiabetic nephropathies

Despite the huge amount of studies looking for candidate genes, the ACE gene remains the unique, well-characterized locus clearly associated with pathogenesis and progression of chronic kidney disease, and with response to treatment with drugs that directly interfere with the renin angiotensin system (RAS), such as angiotensin converting enzyme (ACE) inhibitors and angiotensin II receptor antagonists (ARA). The II genotype is protective against development and progression of type I and type II nephropathy and is associated with a slower progression of nondiabetic proteinuric kidney disease. ACE inhibitors are particularly effective at the stage of normoalbuminuria or microalbuminuria in both type I and type II diabetics with the II genotype, whereas the DD genotype is associated with a better response to ARA therapy in overt nephropathy of type II diabetes and to ACE inhibitors in male patients with nondiabetic proteinuric nephropathies. The role of other RAS or non-RAS polymorphisms and their possible interactions with different ACE I/D genotypes are less clearly defined. Thus, evaluating the ACE I/D polymorphism is a reliable tool to identify patients at risk and those who may benefit the most of renoprotective therapy with ACE inhibitors or ARA. This may guide pharmacologic therapy in individual patients and help design clinical trials in progressive nephropathies. Moreover, it might help optimize prevention and intervention strategies at population levels, in particular, in countries where resources are extremely limited and 1 million patients continue to die every year of cardiovascular or renal disease.

ACE gene polymorphism and losartan treatment in type 2 diabetic patients with nephropathy

Losartan treatment reduced renal outcomes in proteinuric patients with type 2 diabetes in the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) study. It is unknown whether an insertion (I)/deletion (D) polymorphism in the angiotensin I-converting enzyme (ACE) gene predicts renal outcomes and death and influences the effect of losartan in these patients. Pharmacogenetic analyses were performed comparing losartan with placebo administered with conventional blood pressure-lowering therapy in 1435 (95%) of the 1513 RENAAL study patients. The primary endpoint was the composite of doubling of baseline serum creatinine concentration, end-stage renal disease (ESRD) or death. Cox regression models were stratified on baseline proteinuria and included treatment, geographic region, ACE/ID genotype, and treatment x genotype interaction. Within the placebo group, subjects with the ID or DD genotype were more likely than those with the II genotype to reach the composite endpoint (by 17.5% and 38.1%, respectively, P = 0.029) or its individual components. Within the losartan group, genotype did not correlate with reaching the composite endpoint. Compared with placebo, however, losartan reduced the risk of reaching the composite endpoint by 5.8% (95% confidence interval, -23.3, 28.0), 17.6% (3.8, 29.4), and 27.9% (7.0, 44.1) among those with the II, ID, and DD genotypes, respectively. Similar trends were demonstrated for the individual endpoints. In conclusion, proteinuric type 2 diabetic patients with the D allele of the ACE gene have an unfavorable renal prognosis, which can be mitigated and even improved by losartan.

Myxoma of donor origin in a transplanted heart

Myxomas are the most common primary cardiac tumors but their presence in the transplanted heart is extremely rare. We report a case of left atrial myxoma in a patient after heart transplantation. DNA analysis confirmed a donor origin. To our knowledge, this is the first report of myxoma of donor origin in a transplanted heart.

Polimorfismo inserción/deleción del gen de la enzima de conversión de la angiotensina en una población mexicana con nefropatía diabética

BACKGROUND AND OBJECTIVE

Diabetic nephropathy is a polygenic and multifactorial disease. Studies of familial clustering and genetic predisposition suggest that genetic factors are involved. Among candidate genes, the coding for angiotensin-converting enzyme (ACE) polymorphism has been described. Our objective was to investigate the association ACE gene insertion/deletion (I/D) polymorphism with the development of diabetic nephropathy in a Mexican population.

PATIENTS AND METHOD

In a cross-sectional study, we evaluated 204 patients with type 2 diabetes: 43 with incipient diabetic nephropathy, 45 with established diabetic nephropathy and 116 without diabetic nephropathy. Diabetic nephropathy was defined according the American Diabetes Association criteria. The ACE I/D gene polymorphism was detected by polymerase chain reaction.

RESULTS

Patients with type 2 diabetes with both incipient diabetic nephropathy and established diabetic nephropathy significantly differed from controls with respect to variables that determined kidney damage (P<.0001) and serum lipids ( P<.01). The genotype DD was strongly associated with the development of incipient diabetic nephropathy (odds ratio [OR] adjusted = 2.83; 95% confidence interval, 1.74-4.59; P<.0001) and established diabetic nephropathy (OR adjusted = 2.95; 95% CI, 1.83-4.73; P<.0001).

CONCLUSIONS

The ACE DD genotype is associated with the development of incipient diabetic nephropathy and established diabetic nephropathy in a Mexican population.

Renin-angiotensin-aldosterone system polymorphisms: a role or a hole in occurrence and long-term prognosis of acute myocardial infarction at young age

Background

The renin-angiotensin-aldosterone system (RAAS) is involved in the cardiovascular homeostasis as shown by previous studies reporting a positive association between specific RAAS genotypes and an increased risk of myocardial infarction. Anyhow the prognostic role in a long-term follow-up has not been yet investigated.

Aim of the study was to evaluate the influence of the most studied RAAS genetic Single Nucleotide Polymorphisms (SNPs) on the occurrence and the long-term prognosis of acute myocardial infarction (AMI) at young age in an Italian population.

Methods

The study population consisted of 201 patients and 201 controls, matched for age and sex (mean age 40 ± 4 years; 90.5% males). The most frequent conventional risk factors were smoke (p < 0.001), family history for coronary artery diseases (p < 0.001), hypercholesterolemia (p = 0.001) and hypertension (p = 0.002). The tested genetic polymorphisms were angiotensin converting enzyme insertion/deletion (ACE I/D), angiotensin II type 1 receptor (AGTR1) A1166C and aldosterone synthase (CYP11B2) C-344T. Considering a long-term follow-up (9 ± 4 years) we compared genetic polymorphisms of patients with and without events (cardiac death, myocardial infarction, revascularization procedures).

Results

We found a borderline significant association of occurrence of AMI with the ACE D/I polymorphism (DD genotype, 42% in cases vs 31% in controls; p = 0.056). DD genotype remained statistically involved in the incidence of AMI also after adjustment for clinical confounders.

On the other hand, during the 9-year follow-up (65 events, including 13 deaths) we found a role concerning the AGTR1: the AC heterozygous resulted more represented in the event group (p = 0.016) even if not independent from clinical confounders. Anyhow the Kaplan-Meier event free curves seem to confirm the unfavourable role of this polymorphism.

Conclusion

Polymorphisms in RAAS genes can be important in the onset of a first AMI in young patients (ACE, CYP11B2 polymorphisms), but not in the disease progression after a long follow-up period. Larger collaborative studies are needed to confirm these results.

Mechanisms of progression of chronic kidney disease

Chronic kidney disease (CKD) occurs in all age groups, including children. Regardless of the underlying cause, CKD is characterized by progressive scarring that ultimately affects all structures of the kidney. The relentless progression of CKD is postulated to result from a self-perpetuating vicious cycle of fibrosis activated after initial injury. We will review possible mechanisms of progressive renal damage, including systemic and glomerular hypertension, various cytokines and growth factors, with special emphasis on the renin-angiotensin-aldosterone system (RAAS), podocyte loss, dyslipidemia and proteinuria. We will also discuss possible specific mechanisms of tubulointerstitial fibrosis that are not dependent on glomerulosclerosis, and possible underlying predispositions for CKD, such as genetic factors and low nephron number.

Evaluation of atrial and brain natriuretic polypeptides in association with angiotensin-converting enzyme gene polymorphism in Japanese non-diabetic hemodialysis patients

OBJECTIVE

Insertion (I)/deletion (D) polymorphisms in the angiotensin-converting enzyme (ACE) gene have the potential to serve as a marker for an increased risk of cardiovascular events. Increased plasma levels of human atrial natriuretic polypeptide (ANP) and brain natriuretic polypeptide (BNP) are important indexes of cardiac function. The aim of this study was to examine possible relationships between I/D polymorphisms and the myocardial release of ANP and BNP in Japanese hemodialysis (HD) patients (n=131).

MATERIAL AND METHODS

We studied 131 non-diabetic hemodialysis patients. The genotype of ACE gene was determined by polymerase chain reaction with a set of specific timers. ANP and BNP levels were measured before HD.

RESULTS

The plasma levels of ANP and BNP were significantly lower in the DD genotype group compared to those in the II group. Corresponding levels in the ID genotype group were intermediate between those in the DD and II groups. ACE polymorphism was associated with neither ejection fraction nor left ventricular mass/height index (LVMI), as evidenced by echocardiographic findings (n=107). Plasma levels of ANP were significantly correlated with left atrial diameter (LAD) in patients as a whole, but this correlation was only observed in the II genotype group, and not in the DD or ID groups. Plasma levels of BNP were significantly correlated with LAD, left ventricular end systolic diameter and LVMI in patients as a whole, but these correlations were seen only in the II genotype group.

CONCLUSION

The results suggest that the plasma levels of these natriuretic peptides should be evaluated on the basis of ACE polymorphism for assessing cardiac diseases due to volume overload in Japanese HD patients.

Angiotensin-converting enzyme (ACE) inhibition in type 2, diabetic patients – interaction with ACE insertion/deletion polymorphism

Angiotensin-converting enzyme (ACE) insertion(I)/deletion (D) polymorphism may modify the effect of inhibition of the renin-angiotensin-aldosterone system (RAAS) on survival and cardiorenal outcomes in type 2, diabetes. A consecutive cohort of 2089 Chinese type 2 diabetic patients with mean (+/- standard deviation) age of 59.7 +/- 13.1 years were genotyped for this polymorphism by polymerase chain reaction method and were followed prospectively for a median period of 44.6 (interquartile range: 23.7, 57.5) months. Clinical outcomes, including all-cause mortality, cardiovascular and renal end points, were examined. The frequency for I allele was 67.1 and 32.9% for D allele, with observed genotype frequencies of 45.8, 42.6, and 11.6% for 3, DI and DD, respectively. ACE DD polymorphism was an independent predictor for renal end point with hazard ratio (HR) (95% confidence interval) of 1.72 (1.16, 2.56), but not for cardiovascular end point or mortality. After controlling for confounding factors, including ACE I/D genotype, the usage of RAAS inhibitors was associated with reduced risk of mortality (HR 0.34 (0.23, 0.50)) and renal end point (HR 0.55 (0.40, 0.75)). On subgroup analysis, the beneficial effects on survival (II vs DI vs DD: HR 0.29 (0.16, 0.51) vs 0.25 (0.14, 0.46) vs 1.33 (0.41, 4.31)) and renoprotection (II vs DI vs DD: 0.52 (0.30, 0.90) vs 0.43 (0.25, 0.72) vs 0.95 (0.43, 2.12)) were most evident in II and DI carriers. In conclusion, inhibition of RAAS was associated with reduced risk of mortality and occurrence of renal end point in Chinese type 2 diabetic patients. These benefits were most evident among II and DI carriers.

Renin–angiotensin system gene polymorphisms: association with susceptibility to Henoch–Schonlein purpura and renal involvement

The clinical course of Henoch-Schönlein Purpura (HSP) in children is variable, with some patients having a much more rapidly progressing course than others. We investigated whether polymorphisms of the renin-angiotensin system (RAS) genes are involved in HSP. Three RAS genotypes were examined in 114 children with HSP and in 164 healthy children: the angiotensin I converting enzyme (ACE) insertion/deletion polymorphism, the M235T mutation in the angiotensinogen gene (Agt), and the A1166C in the angiotensin II type I receptor (AT1R) gene. Significant differences were observed between HSP patients and control group in the frequency of ACE and Agt genotypes (p=0.004 and p=0.003, respectively). The TT genotype of Agt gene was associated with a 3.5-fold increased risk for Henoch-Schönlein nephritis (HSN) compared with the MM/MT genotype (odds ratio, 3.5; 95% confidence interval, 1.2-10.4). There was a trend to a higher prevalence of the TT genotype of the Agt gene among patients with nephrotic range proteinuria when compared to the patients with mild proteinuria, although the difference did not reach a statistical significance. The results of this study suggest that polymorphisms of ACE gene and Agt gene likely influence the risk of developing HSP. However, among the three genes of the RAS studies, only Agt gene was associated with the susceptibility to HSN. RAS gene polymorphisms studied are not associated with the presence of nephrotic range proteinuria. Additional studies are warranted to verify the correlation between RAS gene polymorphisms and susceptibility to HSP.

Association of the genetic polymorphisms of the renin-angiotensin system with kidney graft long-term outcome: preliminary results

Recent studies have demonstrated some association between the renin-angiotensin system (RAS) activity and the development and progression of different entities as diabetes mellitus (DM) or chronic allograft nephropathy. To investigate these associations, we studied some gene polymorphisms of RAS in a group of renal transplant recipients. We retrospectively analyzed 42 patients who underwent a primary renal transplantation for 2 years. A subgroup of 23 patients (55%) was diagnosed with postransplant DM in accordance with American Diabetes Association 2001 criteria. We studied two RAS gene polymorphisms: the angiotensin-converting enzyme insertion/deletion (ACE I/D) and angiotensinogen (AGTM235T). Genotyping was performed by DNA purification and amplification with a polymerase chain reaction technique. The distributions of genotypes were ACE DD, ID, II: 33%, 48%, 19%; and AGT TT, MT, MM: 15%, 45%, 40%, respectively. We observed a progressive loss in renal function measured by creatinine clearance (Cockroft) in D-allele carriers (DD+ID) between the first and the second transplantation year: 65.3 +/- 4.3 vs 59.8 +/- 4.6 mL/min (P = 0.02); that was not seen in II patients: 68.8 +/- 4.6 vs 68.4 +/- 4 mL/min (P = 0.87). Fifty percent of D-allele carriers developed DM vs 25% of non-D-allele carriers (P = 0.19). Eighty-three percent of homozygous patients for the AGT-TT allele developed DM vs 35% of non TT patients (P = 0.04). There were no significant differences regarding recipient demographic characteristics, type of donor, number and severity of acute rejections, and immunosuppressant treatment between the groups. In conclusion, ACE D-allele seems to be associated with a poorer kidney graft long-term outcome. ACE D and AGT T alleles may be implicated in glucose metabolism disorders after transplantation.