Genetic polymorphism of renin-angiotensin system is not associated with diabetic vascular complications in Japanese subjects with long-term insulin dependent diabetes mellitus

The impact of angiotensin converting enzyme insertion/deletion gene polymorphism on diabetic kidney disease: A debatable issue

OBJECTIVE

The objective of this study was to evaluate the influence of ACE I/D gene polymorphisms on diabetic kidney disease (DKD) risk.

METHODS

All eligible investigations were identified, the number of various genotype in the case and control group were reviewed. The pooled analysis was performed using Stata software.

RESULTS

In overall subjects, 24,321 participants with 12,961 cases and 11,360 controls were included. the pooled analysis showed a significant link between D allele, DD or II genotype and DKD risk (D versus I: OR=1.316, 95% CI: 1.213-1.427, P=0.000; DD versus ID+II: OR=1.414, 95% CI: 1.253-1.595, P=0.000; II versus DD+ID: OR=0.750, 95% CI: 0.647-0.869, P=0.000). The subgroup pooled analysis showed that ACE I/D gene polymorphism was correlated with DKD both in Asian and in Chinese population. In addition, ACE I/D gene polymorphism was correlated with type 2 DKD (D versus I: OR=1.361, 95% CI: 1.243-1.490, P=0.000; DD versus ID+II: OR=1.503, 95% CI: 1.310-1.726, P=0.000; II versus DD+ID: OR=0.738, 95% CI: 0.626 -0.870, P=0.000). However, there was no obvious correlation in Caucasian subjects and type 1 diabetic patients.

CONCLUSION

ACE I/D polymorphisms were correlated with DKD in Asian and type 2 diabetic populations. ACE D allele/DD genotype might be a risk factor, while ACE II genotype might be a protective factor for DKD.

The impact of angiotensin converting enzyme insertion/deletion gene polymorphism on diabetic kidney disease: A debatable issue

OBJECTIVE

The objective of this study was to evaluate the influence of ACE I/D gene polymorphisms on diabetic kidney disease (DKD) risk.

METHODS

All eligible investigations were identified, the number of various genotype in the case and control group were reviewed. The pooled analysis was performed using Stata software.

RESULTS

In overall subjects, 24,321 participants with 12,961 cases and 11,360 controls were included. the pooled analysis showed a significant link between D allele, DD or II genotype and DKD risk (D versus I: OR=1.316, 95% CI: 1.213-1.427, P=0.000; DD versus ID+II: OR=1.414, 95% CI: 1.253-1.595, P=0.000; II versus DD+ID: OR=0.750, 95% CI: 0.647-0.869, P=0.000). The subgroup pooled analysis showed that ACE I/D gene polymorphism was correlated with DKD both in Asian and in Chinese population. In addition, ACE I/D gene polymorphism was correlated with type 2 DKD (D versus I: OR=1.361, 95% CI: 1.243-1.490, P=0.000; DD versus ID+II: OR=1.503, 95% CI: 1.310-1.726, P=0.000; II versus DD+ID: OR=0.738, 95% CI: 0.626 -0.870, P=0.000). However, there was no obvious correlation in Caucasian subjects and type 1 diabetic patients.

CONCLUSION

ACE I/D polymorphisms were correlated with DKD in Asian and type 2 diabetic populations. ACE D allele/DD genotype might be a risk factor, while ACE II genotype might be a protective factor for DKD.

Associations between angiotensinogen M235T polymorphisms and the risk of diabetic nephropathy: A meta-analysis

AIMS

The aim of the present study was to clarify the potential relationship of angiotensinogen (AGT) M235T polymorphism and diabetic nephropathy (DN) risk.

METHODS

Comprehensive electronic search in Pubmed, Web of Science, EBSCO, Embase, the Cochrane Library and China National Knowledge Infrastructure (CNKI) to find original articles about the association between AGT M235T polymorphism and DN risk published before 27 September 2017. Literature quality assessment was performed with the Newcastle-Ottawa Scale. Heterogeneity across studies was assessed using I² statistics. Random-effects model or Fixed-effects model was used to estimate the odds ratios (ORs) with 95% confidence intervals (CIs). Sensitivity analyses to assess the influence of individual studies on the pooled estimate. Publication bias was investigated using funnel plots and Egger's regression test. Analyses were performed by using Stata 15.0.

RESULTS

Overall, 20 eligible studies involving a total of 3822 cases and 3911 controls were included in our meta-analysis. The results showed that AGT M235T polymorphism significantly increased DN risk in recessive model (T/T versus M/T + M/M: OR = 1.35, 95%CI (1.07-1.69), I² = 63.8%, Z = 2.56, P = 0.010), homozygote model (T/T versus M/M: OR = 1.46, 95%CI (1.11-1.92), I² = 62.4%, Z = 2.69, P = 0.007) and allele model (T versus M: OR = 1.17, 95%CI (1.01-1.35), I² = 72.5%, Z = 2.14, P = 0.032); Subgroup analysis by ethnicity showed that AGT M235T polymorphism significantly increased DN risk in recessive model (T/T versus M/T + M/M: OR = 1.39, 95%CI (1.06-1.81), I² = 66.6%, Z = 2.42, P = 0.016), homozygote model (T/T versus M/M: OR = 1.47, 95%CI (1.08-2.01), I² = 67.7%, Z = 2.47, P = 0.013) and allele model (T versus M: OR = 1.18, 95%CI (1.02-1.37), I² = 69.4%, Z = 2.26, P = 0.024) in Caucasian DM population; Subgroup analysis by clinical subtype of DM also showed that AGT M235T polymorphism significantly increased DN risk in recessive model (T/T versus M/T + M/M: OR = 1.28, 95%CI (1.05-1.57), I² = 21.3%, Z = 2.40, P = 0.016), homozygote model (T/T versus M/M: OR = 1.41, 95%CI (1.04-1.92), I² = 30.2%, Z = 2.23, P = 0.026) and allele model (T versus M: OR = 1.14, 95%CI (1.03-1.28), I² = 35.5%, Z = 2.44, P = 0.015) in type 1 diabetes patients.

CONCLUSION

Our study showed that AGT M235T homozygous mutation significantly increase DN risk in Caucasian DM population and type 1 diabetes patients.

Angiotensin II receptor type 1 A1166C modifies the association between angiotensinogen M235T and chronic kidney disease

Single nucleotide polymorphisms (SNPs) in renin-angiotensin system (RAS) genes are associated with RAS imbalance and chronic kidney disease (CKD). We performed a case-control study and meta-analysis to investigate the association between angiotensinogen (AGT) M235T polymorphism and CKD. A total of 634 patients with end-stage renal disease and 739 healthy controls were studied. We also searched PubMed and the Cochrane Library to identify prospective observational studies published before December 2015. We found that the TT and MT genotypes were associated with a higher risk of CKD than the MM genotype (odds ratio [OR]: 3.56; 95% confidence interval [CI]: 1.14-11.16 and OR: 2.93; 95% CI: 0.91-9.46, respectively). Thirty-eight study populations were included in the meta-analysis. The T allele was associated with a higher risk of CKD than the M allele in all populations (OR: 1.19; 95% CI: 1.08-1.32). The OR was 1.33 in Asians (95% CI: 1.06-1.67) and 1.10 in Caucasians (95% CI: 1.02-1.18). Evaluation of gene-gene and gene-environment interactions using epistasis analysis revealed an interaction between AGT M235T and angiotensin II receptor type 1 A1166C in CKD (OR: 0.767; 95% CI: 0.609-0.965). Genetic testing for CKD in high-risk individuals may be an effective strategy for CKD prevention.

Association of Angiotensin-Converting Enzyme Gene Polymorphisms and Nephropathy in Diabetic Patients at a Tertiary Care Centre in South India

Background:

Genetic polymorphisms of the angiotensin-renin pathway have been thought to influence the development of diabetic nephropathy. However, there are conflicting results regarding this association in previous studies on populations with varying ethnicity.

Aims:

Primary aim was to compare the frequency of distribution of angiotensin-converting enzyme (ACE) gene (insertion/deletion [I/D]) polymorphism in Tamilian Indian type 2 diabetic individuals with and without microalbuminuria. Secondary objective was to compare the frequency of distribution of the 3 genotypes in diabetic patients with urinary albumin/creatinine ratio (ACR) < 30 mg/dL, urinary ACR = 30 to 300 mg/dL, and urinary ACR > 300 mg/dL.

Methods:

A total of 179 consecutive diabetic individuals between 40 and 70 years, from Puducherry and Tamilnadu of Dravidian descent participated in the study conducted from 2012 to 2014. Inclusion criteria were as follows: age ≥ 40 years and duration of type 2 diabetes mellitus for ≥5 years. Patients were divided into 2 groups based on ACR values. Group 1 consisted of 50 individuals with urinary ACR < 30 mg/g of creatinine, and group 2 consisted of 129 individuals with urinary ACR > 30 mg/g. Angiotensin I–converting enzyme (ACE) gene polymorphism was determined by allele-specific polymerase chain reaction method using a primer pair flanking the polymorphic region of its intron 16. Furthermore, group 2 patients were subdivided into those with urinary ACR = 30 to 300 mg/g of creatinine and those with urinary ACR > 300 mg/g of creatinine, and distribution of ACE gene polymorphism was compared in the three groups.

Statistics:

Statistical analysis was done using SPSS version 17.0. Independent Student t test was used to compare mean values between the 2 groups. Odds ratio was calculated for testing association between ACE gene (I/D) polymorphism and presence of microalbuminuria. P < .05 was considered significant. Comparison of ACE genotypes among 3 groups of patients (ACR < 30 mg/g, ACR = 30-300 mg/g, and ACR > 300 mg/g) was done using 1-way analysis of variance with Bonferroni multiple comparison test as post hoc analysis.

Conclusions:

Heterozygous I/D genotype was more frequent in the study population (45.8%) than the other genotypes. There was no difference in the genotype distribution in patients with varying levels of albuminuria.

Angiotensin-converting enzyme insertion/deletion polymorphism contributes high risk for chronic kidney disease in Asian male with hypertension--a meta-regression analysis of 98 observational studies

Background

Associations between angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphisms and chronic kidney disease (CKD) have been extensively studied, with most studies reporting that individuals with the D allele have a higher risk. Although some factors, such as ethnicity, may moderate the association between ACE I/D polymorphisms and CKD risk, gender-dependent effects on the CKD risk remain controversial.

Objectives

This study investigated the gender-dependent effects of ACE I/D polymorphisms on CKD risk.

Data sources

PubMed, the Cochrane library, and EMBASE were searched for studies published before January 2013.

Study eligibility criteria, participants, and interventions

Cross-sectional surveys and case–control studies analyzing ACE I/D polymorphisms and CKD were included. They were required to match the following criteria: age >18 years, absence of rare diseases, and Asian or Caucasian ethnicity.

Study appraisal and synthesis methods

The effect of carrying the D allele on CKD risk was assessed by meta-analysis and meta-regression using random-effects models.

Results

Ethnicity [odds ratio (OR): 1.24; 95% confidence interval (CI): 1.08–1.42] and hypertension (OR: 1.55; 95% CI: 1.04–2.32) had significant moderate effects on the association between ACE I/D polymorphisms and CKD risk, but they were not significant in the diabetic nephropathy subgroup. Males had higher OR for the association between ACE I/D polymorphisms and CKD risk than females in Asians but not Caucasians, regardless of adjustment for hypertension (p<0.05). In subgroup analyses, this result was significant in the nondiabetic nephropathy group. Compared with the I allele, the D allele had the highest risk (OR: 3.75; 95% CI: 1.84–7.65) for CKD in hypertensive Asian males.

Conclusions and implications of key findings

The ACE I/D polymorphisms may incur the highest risk for increasing CKD in hypertensive Asian males.

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.

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.

Effect of angiotensin II on iron-transporting protein expression and subsequent intracellular labile iron concentration in human glomerular endothelial cells

Angiotensin II (Ang II)-induced endothelial injury, which is associated with atherosclerosis, is believed to be mediated by intracellular reactive oxygen species (ROS) through stimulation of nicotinamide adenine dinucleotide phosphate oxidase (NOX). Iron is essential for the amplification of oxidative stress. In this study, we investigated whether Ang II altered iron metabolism and whether the Ang II-induced endothelial injury is attributable to changes in iron metabolism of human glomerular endothelial cells (HGECs). When 90% iron-saturated human transferrin (90% Tf) was applied to HGECs without Ang II, the labile ferrous iron level was same as the effect of control in spite of a significant increase in the total cellular iron concentration. Treatment with Ang II and 30% Tf or 90% Tf significantly (P<0.01) increased the intracellular iron concentration, as well as labile ferrous iron and protein oxidation levels, compared with the effect of separate administration of each compound. Ang II treatment facilitated the protein expression of the Tf receptor, divalent metal transporter 1, and ferroportin 1 in a dose- and time-dependent manner. It was also found that simultaneous exposure of HGECs to Ang II and 90% Tf accelerated hydroxyl radical production, as shown by using an electron paramagnetic resonance spectrometer. These results suggest that Ang II not only induces production of ROS by NOX activation but also iron incorporation followed by an increase in labile iron in HGECs. Both of these events may participate in the progression of oxidative stress because of endothelial cell dysfunction through ferrous iron-mediated ROS generation.

Assessing genetic susceptibility to diabetic nephropathy

Diabetic nephropathy is a serious complication of diabetes and the leading cause of end-stage renal disease. Studies indicate both environmental and genetic factors contribute to the development and progression of diabetic nephropathy. In particular, epidemiological evidence shows a familial clustering of nephropathy in siblings with diabetes, supporting an important role of genetic susceptibility in the pathogenesis of diabetic nephropathy. A common approach in genetic research is assessment of candidate gene polymorphisms using case-control analysis; a number of studies have evaluated predictable candidate genes for diabetic nephropathy. In contrast, only a few studies have used a whole genome approach, such as scanning of micro-satellite markers, in the assessment of genetic susceptibility to diabetic nephropathy. A whole genome linkage analysis using families of Pima Indians showed susceptibility loci for diabetic nephropathy on chromosome 3, 7, and 20. Another linkage analysis using discordant sib-pairs of Caucasian families with type 1 diabetes identified a critical area on chromosome 3q. However, these results have been inconclusive and further investigation is required. Recently, a genome-wide, case-control analysis identifying susceptibility genes for diabetic nephropathy was performed. As a result, a single nucleotide polymorphism in exon 23 of the solute carrier family 12 (sodium-chloride cotransporter) member 3 gene was found to be strongly associated with diabetic nephropathy. Although further assessment of this polymorphism is needed, this strategy offers great promise in the identification of genetic factors predisposing patients to diabetic nephropathy. Identification of genetic susceptibility markers may offer new hope in the diagnosis and treatment of diabetic nephropathy.

Frequency of angiotensin-converting enzyme gene polymorphism in Turkish type 2 diabetic patients

We aimed to investigate the angiotensin-converting enzyme (ACE) gene polymorphism, ACE activity and their associations with diabetic complications in Turkish patients with type 2 diabetes mellitus. A total of 143 patients and 133 controls were screened for ACE gene I/D polymorphism by using polymerase chain reaction. Serum ACE activities were determined spectrophotometrically. There was no significant difference in the distribution of ACE I/D genotypes between patients and controls. The patients with DD genotype had a higher ACE activity than those with ID and II. Hypertensive diabetic patients with DD genotype had higher ACE activities than those with ID and II. There was no significant difference in the distribution of ACE I/D genotypes between patients with and without nephropathy, retinopathy and hypertension except for patients with and without neuropathy. In patients with DD genotype, creatinine clearance correlated with duration of diabetes. The grade of retinopathy was correlated with duration of diabetes in DD and ID genotypes. The highest ACE activity was measured in hypertensive diabetics with DD genotype. ID genotype was suggested to be a risk factor and II was suggested to be protective for diabetic neuropathy. The DD and ID genotypes might be a predictor for the development of retinopathy in relation to duration of diabetes.

Angiotensin-I converting enzyme insertion/deletion polymorphism and its association with diabetic nephropathy: a meta-analysis of studies reported between 1994 and 2004 and comprising 14,727 subjects

AIMS/HYPOTHESIS

The ACE insertion/deletion polymorphism has been examined for association with diabetic nephropathy over the past decade with conflicting results. To clarify this situation, we conducted a comprehensive meta-analysis encompassing all relevant studies that were published between 1994 and 2004 and investigated this potential genetic association.

METHODS

A total of 14,727 subjects from 47 studies was included in this meta-analysis. Cases (n=8,663) were type 1 or 2 diabetic subjects with incipient (microalbuminuria) or advanced diabetic nephropathy (proteinuria, chronic renal failure, end-stage renal disease). Control subjects (n=6,064) were predominantly normoalbuminuric.

RESULTS

No obvious publication bias was detected. Using a minimal-case definition based on incipient diabetic nephropathy, subjects with the II genotype had a 22% lower risk of diabetic nephropathy than carriers of the D allele (pooled odds ratio [OR]=0.78, 95% CI=0.69-0.88). While there was a reduced risk of diabetic nephropathy associated with the II genotype among Caucasians with either type 1 or type 2 diabetes, the association was most marked among type 2 diabetic Asians (Chinese, Japanese, Koreans) (OR=0.65, 95% CI=0. 51-0.83). This OR is significantly different from the OR of 0.90 (95% CI= 0.78-1.04) that was obtained for type 2 diabetic Caucasians (p=0.019). Using a stricter case definition based on advanced diabetic nephropathy, a comparable risk reduction of 24-32% was observed among the three subgroups, although statistical significance was reached only among Asians.

CONCLUSIONS/INTERPRETATION

The results of our meta-analysis support a genetic association of the ACE Ins/Del polymorphism with diabetic nephropathy. These findings may have implications for the management of diabetic nephropathy using ACE inhibitors especially among type 2 diabetic Asians.

ACE gene polymorphism, left ventricular geometry, and mortality in diabetic patients with end-stage renal disease

The objectives of this study were to determine the association between angiotensin converting enzyme (ACE) gene polymorphism and left ventricular (LV) geometry, and to clarify independent effects of ACE genotype on mortality after commencing dialysis in diabetic patients with end-stage renal disease (ESRD). A total of 106 diabetic patients, 71 men and 35 women, 11 type 1 and 95 type 2 diabetic, 57 +/- 12 (mean +/- standard deviation (S.D.)) years of age, who started dialysis were studied. Patients with cardiac diseases and those treated with ACE inhibitors were excluded because of potential effects on LV performance. Echocardiographic examination was performed within +/-2 months of the start of dialysis. Relation between ACE genotype and LV mass index (LVMI) or relative wall thickness (RWT) at onset of dialysis, and impact of ACE genotype on survival after commencing dialysis were evaluated. There were no significant differences in LVMI or RWT in the three ACE genotype groups at onset of dialysis. However, mortality of patients with the ACE-DD genotype was significantly higher than patients with the DI and II genotypes (hazard ratio, 2.318; P=0.043), based on a survival analysis with a mean follow-up duration of 60 months. The higher mortality in patients with the DD genotype was confirmed to be independent of LV hypertrophy and increases in RWT. In diabetic patients with ESRD, ACE genotype has no association with LV mass or RWT at the start of dialysis, but does have an independent impact on patient survival thereafter.

Angiotensin-converting enzyme gene polymorphism as a potent risk factor for developing microalbuminuria in Japanese patients with type 2 diabetes mellitus: a 9-year follow-up study

To clarify the risk factors for developing microalbuminuria in patients with type 2 diabetes mellitus, a longitudinal observational study was performed. Fifty patients with normoalbuminuria were recruited and treated conventionally for 9 years. Polymorphisms of the angiotensin-converting enzyme (ACE) gene and the angiotensinogen M235T polymorphism were examined. During the study period, 12 of the 50 patients developed microalbuminuria; no patients progressed to macroalbuminuria. Multiple logistic regression analysis was performed using age, duration of diabetes, body mass index, haemoglobin A1c' blood pressure, serum lipid profile and genetic polymorphisms as independent variables and development of microalbuminuria as the dependent variable. The D allele of the ACE gene was an independent and significant variable. We conclude that the ACE gene D allele polymorphism is a potent risk factor for developing microalbuminuria in type 2 diabetic patients.

Angiotensin-converting enzyme gene polymorphisms in renal disease: clinically relevant?

The most recent studies of the effect of polymorphisms of the angiotensin-converting enzyme gene on the pathogenesis of renal diseases and the response to treatment with angiotensin-converting enzyme inhibitors continue to produce conflicting results. Large prospective studies are required before angiotensin-converting enzyme genotyping will provide information that will assist in the assessment of prognosis and response to angiotensin-converting enzyme inhibitor treatment in individual patients. Until such studies are performed, all patients with chronic renal disease, regardless of angiotensin-converting enzyme genotype, should be considered candidates for angiotensin-converting enzyme inhibitor therapy.