The D allele of the angiotensin-converting enzyme insertion/ deletion (I/D) polymorphism is a risk factor for type 2 diabetes in a population-based Japanese sample

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.

Association of ACE I/D and PAI-1 4G/5G polymorphisms with susceptibility to type 2 diabetes mellitus

BACKGROUND

A number of studies were carried out to assess the association of angiotensin I converting enzyme (ACE) I/D and plasminogen activator inhibitor-1 (PAI-1-1) 4G/5G polymorphisms with susceptibility to type 2 diabetes mellitus (T2DM). However, there are a few studies in Iranian patients with T2DM. Here, we tested for an association of ACE I/D and PAI-1 4G/5G polymorphisms with T2DM risk.

METHODS

One hundred-eighteen patients with T2DM and 125 healthy subjects were participates in this study. The ACE I/D (rs4340) and PAI-1 4G/5G (rs1799889) polymorphisms was genotyped by conventional and PCR-RFLP assays, receptively. The associations was evaluated by calculating the odds ratio (OR) and 95% confidence interval (95% CI).

RESULTS

The genotype distribution of ACE I/D and PAI-1 4G/5G polymorphisms were not deviated from the Hardy-Weinberg equilibrium in healthy controls. The ACE II, ID, and DD genotype frequencies were 18.6%, 48.3%, and 33.1% in the T2DM patients versus 24.0%, 45.6% and 30.4% in healthy subjects, respectively. The PAI-1 4G/4G, 4G/5G, and 5G/5G genotype frequencies were 16.9%, 51.7%, and 31.4% in cases versus 24.8%, 57.6% and 17.6% in controls, respectively. There is a significant distribution in genotype/allele of PAI-1 4G/4G between cases with T2DM and healthy control, but not for ACE I/D. Moreover, the 5G/5G genotype is significantly (OR = 2.139, CI 95% 1.171-3.907, p = 0.013) increased the risk of T2DM by two folds in the cases than healthy controls.

CONCLUSIONS

Our findings suggest that PAI-1 4G/5G may be likelihood risk factor for the development of T2DM in the Iranian patients. The higher frequency of PAI-1 5G/5G genotype in patients with T2DM revealed that individuals with the 5G allele may be at higher risk of T2DM development than those with 4G. However, there was no significant association between ACE I/D polymorphism and T2DM in our population. Future rigorous, well-designed studies with larger sample should replicate this study to confirm our findings in Iranian T2DM patients.

Association of ACE I/D gene polymorphism and related risk factors in impaired fasting glucose and type 2 diabetes: a study among two tribal populations of North-East India

BACKGROUND

Type 2 diabetes is a serious public health concern in India, even the indigenous tribal populations are not left unaffected. The present study aims to understand the association of major risk factors i.e. obesity, hypertension, dyslipidemia, ACE I/D polymorphism with impaired fasting glucose (IFG) and type 2 diabetes (T2D) among two different Mendelian populations of North East India.

METHODS

Demographic, somatometric, physiological variables along with fasting blood samples were collected from 609 individuals. The participants were screened for ACE I/D polymorphism.

RESULTS

ACE I/D polymorphism was found to follow HWE among Liangmai tribe but not among Mizo tribe. Distribution of DD genotype/D allele was found to be significantly higher for T2D among Mizo tribe. Significant association were observed between DD genotype/D allele of ACE I/D polymorphism and TC as well as LDL with both IFG and T2D only in Mizo tribe.

CONCLUSIONS

The present study is an example of gene-environment interaction where DD genotype or D allele and dyslipidemia (high TC and high LDL) are posing risk for IFG and T2D both independently and in combination only among Mizo tribe with relatively less physical activity attributed to their residence in less hilly terrain however Liangmai tribe which resides in high hilly terrain shows no such association.

Association between Angiotensin-Converting Enzyme- Insertion/Deletion Polymorphism and Diabetes Mellitus-2 in Saudi Population

Objectives:

The association of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and the development of type 2 diabetes mellitus (T2DM) has been debated vigorously but still remains controversial. Therefore, the current study was designed to determine the possible association between ACE I/D polymorphism and T2DM and hypertension (HTN) in a population of Saudi Arabian participants.

Methods:

A total of 143 individuals were recruited for the study, consisting of 74 controls and 69 patients with T2DM. Genotyping was performed via polymerase chain reaction.

Results:

The genotype frequencies for DD, ID and II in controls were 52.7%, 39.2% and 8.1%, whereas in T2D patients it was 52.2%, 40.6% and 7.2% respectively. The DD frequency was highest out of the three genotypes in both the controls and the T2DM patients.

Conclusion:

There was no significant difference found in the genotype and allele frequencies between cases and controls, suggesting that insertion/deletion polymorphism in the ACE gene may not be associated with an increased susceptibility to type 2 diabetes in our study population.

Angiotensin-converting enzyme insertion/deletion (I/D) gene polymorphism in Iraqi type 2 diabetic patients: association with the risk of cardiac autonomic neuropathy

Background

Studies have shown a direct association between angiotensin-converting enzyme (ACE) and diabetic neuropathies. As such, ACE gene polymorphisms could be a risk factor for cardiac autonomic neuropathy (CAN) in patients with diabetes. The objective of our study was to investigate the association of the ACE I/D gene polymorphism with the development of CAN in Iraqi patients with type 2 diabetes mellitus (T2DM).

Results

This is a cross-sectional study that included 142 patients with T2DM comprising 62 males and 80 females, and 100 volunteers served as a healthy control group. Cardiac autonomic functions were tested using four standard Ewing’s noninvasive tests. Blood samples were taken for genetic evaluation of an ACE gene I/D polymorphism.

Analyzing ACE gene polymorphism revealed that the D allele was far more frequent among patients with diabetes than healthy control subjects (76.07% vs. 62.67%). The frequency of I/I, I/D, and D/D genotypes in patients with diabetes was 8.55%, 30.77%, and 60.68%, respectively, compared with 18.67%, 37.33%, and 44%, respectively, in controls with a significant difference in mutant homozygous genotype. However, there were no significant differences in these genotypes between patients with and without CAN. Although patients with CAN showed a much higher frequency of D allele than those without CAN, the difference did not reach significance (p = 0.054).

Conclusion

The DD genotype and D allele of the ACE I/D gene polymorphism can be a risk factor for T2DM, and the D allele of this polymorphism can even be associated with the development of CAN in these patients.

Angiotensin-converting enzyme gene polymorphism and digestive system cancer risk: A meta-analysis based on 9656 subjects

The angiotensin-converting enzyme (ACE) is the major regulator of the renin-angiotensin system, and it has been reported that genetic polymorphisms at this locus are associated with risk in numerous types of human cancers. In the current meta-analysis, we aimed to evaluate the association between the ACE Gene insertion/deletion (I/D) polymorphism (DD vs II) and digestive system cancer susceptibility. A total of 19 case-control studies among 3722 patients with seven different types of cancer were included in this meta-analysis. In the pooled analysis, the relationship between the ACE I/D polymorphism and digestive system cancer risk was not statistically significant (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.68-1.29; P = 0.65; random model). Furthermore, subgroup analyses by cancer type also did not reveal an association between ACE polymorphisms and colorectal cancer (OR, 1.14; 95% CI, 0.823-1.58; P = 0.43; random effect model) and gastric cancer (OR, 0.79; 95% CI, 0.51-1.22; P = 0.28; random effect model). These findings indicate that ACE polymorphisms in the digestive tract may still affect the survival of cancer patients, and future studies into the topic of effect of ACE on cancer prognosis are warranted.

Association of eNOS and ACE gene polymorphisms as a genetic risk factor in gestational diabetes in Iranian women

Background

Gestational diabetes mellitus (GDM) is the most popular metabolic disease during pregnancy. The aim of the present study was to investigate any possible association between eNOS Glu298Asp and ACE I/D gene polymorphisms and the risk of GDM in a group of Iranian pregnant women.

Methods

In this case-control study 204 pregnant women were recruited (94 cases and 110 controls). Genomic DNA was isolated from whole blood and genotyping was performed by the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR- RFLP) and only PCR for eNOS and ACE polymorphisms respectively.

Results

Frequencies of GT and TT genotype of eNOS polymorphism among women with and without GDM were 67.90% vs. 74.47 and 7.41% vs. 8.51% respectively (P = 0.4). Corresponding figures for DD genotype of ACE polymorphism among GDM patients was more than that in healthy women (51.65% vs. 63.81% respectively). Conversely, ACE heterozygote genotype was more common in diabetic women (35.16% vs. 26.67% respectively). Although these differences were not statistically significant (P = 0.2).

Conclusions

Our study showed that there is no association between the presence of eNOS and ACE gene polymorphisms and developing gestational diabetes mellitus among pregnant women in our population. Further longitudinal and multicenter studies should be carried out to assess the exact metabolic effects of these polymorphisms.

The relationship between of ACE I/D and the MTHFR C677T polymorphisms in the pathophysiology of type 2 diabetes mellitus in a population of Brazilian obese patients

Objectives This study aimed to evaluate the frequencies of the angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) and methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphisms in obese patients with and without type 2 diabetes mellitus (T2DM). Subjects and methods These polymorphisms were analyzed by polymerase chain reaction in 125 patients with obesity, 47 (T2DM) and 78 (Control Group). Results No significant difference was found on comparing the T2DM and Control Groups in respect to the genotypic frequencies of the polymorphisms - (II: 13.3% vs. 12.0%; ID: 37.8% vs. 37.3; DD: 48.9% vs. 50.7%; CC: 36.2% vs. 39.0%; CT: 46.8% vs. 49.3%; TT: 17.0% vs. 11.7%), and alleles (I: 32.2% vs. 30.7%; D: 67.8% vs. 69.3%; C: 59.6% vs. 63.6%; T: 40.4% vs. 36.4%) and their synergisms in the pathophysiology of T2DM. On analyzing the T2DM Group, there were no significant differences in the presence of complications. In this population of Brazilian obese patients, no correlation was found between the ACE and MTHFR polymorphisms in the development of T2DM. Conclusion Analyzing only the group with diabetes, there was also no relationship between these polymorphisms and comorbidities.

Association between risk of type 2 diabetes mellitus and angiotensin-converting enzyme insertion/deletion gene polymorphisms in a Saudi Arabian population

The link between the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and the prevalence of type 2 diabetes mellitus (T2DM) developing in the Saudi Arabian population remains controversial. The aim of the present study was to evaluate the association between the ACE I/D gene polymorphism and the risk of developing T2DM and hypertension (HTN) in Saudi Arabian individuals. A total of 220 individuals consisting of 48 control subjects, 70 T2DM, 48 HTN, and 54 T2DM with HTN patients were recruited. Genotyping was performed by polymerase chain reaction initially and mistyping of the DD genotypes was conducted with an insertion-specific primer. The genotyping frequency for the II, ID and DD polymorphism of the ACE gene was 6.8, 42.6 and 48.6% in T2DM patients, 4.2, 50 and 45.8% in HTN patients, 5.6, 55.5 and 38.9% in T2DM patients with HTN and 58.3, 37.5 and 4.2% in control subjects, respectively. The frequency for the D allele was 70% in T2DM patients, 70.8% in HTN patients and 66.7% in T2DM patients with HTN as compared with 22.9% in the control subjects. The genotype and allele frequency of the ACE gene polymorphism varied significantly (P<0.05) in the patients when compared with the control subjects. The current study demonstrated that the ID/DD genotype and the D allele of the ACE gene I/D polymorphism were strongly associated with the risk of T2DM and HTN developing in a Saudi Arabian population.

Relationship between angiotensin I-converting enzyme insertion/deletion gene polymorphism and retinal vein occlusion

To evaluate the association between angiotensin I-converting enzyme insertion/deletion (ACE I/D) gene polymorphism and retinal vein occlusion (RVO). A total of 80 patients with retinal vein occlusion who was admitted to the Eye Department of Kartal Training and Research Hospital between 2008 and 2011, and 80 subjects were enrolled in this retrospective case–control study. Patients who experienced RVO within one week to six months of study enrolment were included, and those with coronary artery diseases, prior myocardial infarction history and coagulation disturbances were excluded from the study. The diagnosis was made by ophthalmoscopic fundus examination and fluorescein angiography. The ACE gene I/D polymorphism was determined by polymerase chain reaction, and the ACE gene was classified into three types: I/I, I/D and D/D. In multivariate logistic regression analysis, ACE D/D genotype (p = 0.035), diabetes-mellitus (p = 0.019) and hypertension (p = 0.001) were found to be independent predictive factors for RVO. The results of the present study reveal that ACE D/D polymorphism is an independent predictive factor for RVO. However, one cannot definitely conclude that ACE gene polymorphism is a risk factor for retinal vein occlusion.

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.

Angiotensinogen polymorphisms and post-transplantation diabetes mellitus in Korean renal transplant subjects

BACKGROUND

Post-transplant diabetes mellitus (PTDM) is a common and serious metabolic complication. Genetic polymorphisms of angiotensin-converting enzyme (ACE) and angiotensinogen (AGT) genes have been reported to be related to diabetes mellitus and insulin sensitivity; however, the role of these genes in the development of PTDM is not known. For this purpose, we investigated the association of ACE and AGT genetic polymorphisms with PTDM.

METHODS

A total of 302 subjects without previously diagnosed diabetes who had received kidney transplants were included. One ACE single nucleotide polymorphism (SNP) (rs4291) and two AGT SNPs (rs 699 and rs 4762) were genotyped from genomic DNA with direct sequencing.

RESULTS

PTDM developed in 49 (16.2%) of 302 subjects. Subjects in the PTDM were older than those in the non-PTDM. There was a significant difference between the two groups in tacrolimus use (p=0.03). Of the three SNPs, the rs4762 of the AGT gene was significantly associated with the development of PTDM in the dominant models (p = 0.03) after adjusting for age and tacrolimus usage.

CONCLUSIONS

AGT gene rs4762 polymorphisms may serve as genetic markers for the development of PTDM. The exact molecular mechanisms still need to be clarified.

Association of angiotensin-converting enzyme (ACE) and fatty acid binding protein 2 (FABP2) genes polymorphism with type 2 diabetes mellitus in Northern India

BACKGROUND

Type 2 diabetes mellitus (T2DM) is growing in an epidemic manner across the world with an expected doubling of the incidence to millions of affected individuals in the last decades. At present, adequate data are not available regarding the ACE and FABP2 polymorphisms and their susceptibility with T2DM cases in the North Indian population. Thus we conceived the need for further study of ACE (I/D) and FABP2 (Ala54Thr) genes polymorphism and its susceptibility to T2DM in the North Indian population.

MATERIALS AND METHODS

In this study, a total of 300 subjects (including 190 T2DM cases and 110 controls) participated. ACE and FABP2 gene polymorphisms in the cases and controls were evaluated by polymerase chain reaction and restriction fragment length polymorphism.

RESULTS

The frequencies of ACE I/I, I/D and D/D genotypes in T2DM cases and controls were 28.73%, 55.17%, 16.09% and 13.63%, 57.95%, 28.40%, respectively. The frequencies of FABP2 Ala54Ala, Ala54Thr and Thr54Thr in T2DM cases were 18.39%, 66.66%, 14.94% and 22.72%, 61.36%, 15.90% in controls, respectively. ACE I/I genotype was significantly more frequent in cases as compared to controls (p = 0.003, χ(2) = 9.13).

CONCLUSION

It appears that the ACE I/I genotype frequency was significantly higher in the T2DM cases as compared to the controls.

ACE I/D and MTHFR C677T polymorphisms are significantly associated with type 2 diabetes in Arab ethnicity: a meta-analysis

In this meta-analysis study, SNPs were investigated for their association with type 2 diabetes (T2D) in both Arab and Caucasian ethnicities. A total of 55 SNPs were analyzed, of which 11 fulfilled the selection criteria, and were used for analysis. It was found that TCF7L2 rs7903146 was significantly associated with a pooled OR of 1.155 (95%C.I.=1.059-1.259), p<0.0001 and I(2)=78.30% among the Arab population, whereas among Caucasians, the pooled OR was 1.45 (95%C.I.=1.386-1.516), p<0.0001 and I(2)=77.20%. KCNJ11 rs5219 was significantly associated in both the populations with a pooled OR of 1.176(1.092-1.268), p<0.0001 and I(2)=32.40% in Caucasians and a pooled OR of 1.28(1.111-1.475), p=0.001 among Arabs. The ACE I/D polymorphism was found to be significantly associated with a pooled OR of 1.992 (95%C.I.=1.774-2.236), p<0.0001 and I(2)=83.20% among the Arab population, whereas among Caucasians, the pooled OR was 1.078 (95%C.I.=0.993-1.17), p=0.073 and I(2)=0%. Similarly, MTHFR C677T polymorphism was also found to be significantly associated among Arabs with a pooled OR of 1.924 (95%C.I.=1.606-2.304), p<0.0001 and I(2)=27.20%, whereas among Caucasians, the pooled OR was 0.986 (95%C.I.=0.868-1.122), p=0.835 and I(2)=0%. Meanwhile PPARG-2 Pro12Ala, CDKN2A/2B rs10811661, IGF2BP2 rs4402960, HHEX rs7923837, CDKAL1 rs7754840, EXT2 rs1113132 and SLC30A8 rs13266634 were found to have no significant association with T2D among Arabs. In conclusion, it seems from this study that both Arabs and Caucasians have different SNPs associated with T2D. Moreover, this study sheds light on the profound necessity for further investigations addressing the question of the genetic components of T2D in Arabs.

ACE I/D and eNOS E298D gene polymorphisms in Saudi subjects with hypertension

BACKGROUND

Hypertension has a multifactorial background based on genetic and environmental interactive factors.

OBJECTIVES

We aimed to test for the association of the angiotensin-converting enzyme (ACE) and endothelial nitric oxide synthase (eNOS) gene polymorphisms with hypertension.

SUBJECTS AND METHODS

Participants included 120 Saudi patients with hypertension and 250 normal healthy controls. For all participants, DNA was processed for characterization of ACE I/D and eNOS E298D gene polymorphisms.

RESULTS

Hypertensive cases showed a significantly higher frequency of the ACE mutant D allele carriage (98.3% vs. 92.4%, p = 0.028, OR = 4.8). Cases with hypertension associated with diabetes and obesity showed 100% mutant D allele carriage. Regarding the eNOS E298D polymorphism, the frequency of the mutant D allele carriage was only observed to be higher among cases with hypertension associated with diabetes and obesity, in comparison with controls, yet not reaching statistical significance (41.2% vs. 34%, p > 0.05).

CONCLUSIONS

There is increased frequency of ACE and eNOS mutant allele carriage among Saudi patients affected with hypertension, particularly if accompanied by obesity and diabetes.

Association of angiotensin I converting enzyme, angiotensin II type 1 receptor and angiotensin I converting enzyme 2 gene polymorphisms with the dyslipidemia in type 2 diabetic patients of Chinese Han origin

OBJECTIVE

To investigate whether the genetic polymorphisms in the angiotensin I converting enzyme (ACE) (insertion/ deletion, or I/D), angiotensin II type 1 receptor (AT1R) (rs5186), and ACE2 (rs2285666) could be associated with dyslipidemia in Type 2 diabetic (T2D) patients of Chinese Han origin.

DESIGN AND METHODS

The above 3 polymorphisms were genotyped in a total of 282 patients with T2D and dyslipidemia (Group A), 182 patients with T2D but without dyslipidemia (Group B), and 324 healthy controls. The association between a certain polymorphism and each group was assessed by an odds ratio (OR).

RESULTS

The D allele of the ACE (I/D) was significantly associated with the risk of T2D accompanying dyslipidemia between group A and controls [OR=1.37, 95% confidence interval (CI)=1.08-1.74; p=0.010], and significant association of the D allele with dyslipidemia was also observed in diabetic patients (OR=1.88, 95% CI=1.40-2.54; p<0.001). Furthermore, the ID genotype had a decreased risk of developing T2D without dyslipidemia as compared with controls (OR=0.52, 95% CI=0.32-0.82; p=0.0060). The distributions of the AT1R (rs5186) and ACE2 (rs2285666) genotypes and alleles did not differ between T2D patients with or without dyslipidemia and the controls.

CONCLUSIONS

This study demonstrates that the ACE (I/D) polymorphism is associated with T2D, regardless of the absence or presence of dyslipidemia. The polymorphisms in the AT1R (rs5186) and ACE2 (rs2285666) seem to play lesser roles in the development of T2D.

No association between ACE polymorphism and risk of nasopharyngeal carcinoma

Emerging evidence has shown that angiotensin I-converting enzyme (ACE) plays pivotal roles not only in the regulation of cardiovascular homeostasis but also in the process of tumorigenesis. A common ACE I/D polymorphism has been found to be functional, with the D allele displaying a higher plasma ACE level and ACE activity. The purpose of this study was to investigate whether the ACE I/D polymorphism was related to the risk of nasopharyngeal carcinoma (NPC). The study included 175 patients with NPC and 279 age- and sex-matched control subjects. The ACE I/D polymorphism was identified by a polymerase chain reaction analysis. No association was found between the ACE I/D polymorphism and risk of NPC (ID vs. II: odds ratio [OR] = 0.77, 95% confidence interval [CI] 0.51-1.17; DD vs. II: OR = 0.98, 95%CI 0.56-1.72, respectively). This finding indicates that the ACE I/D polymorphism may not play a role in susceptibility to NPC. Further studies are warranted to confirm this finding, especially in ethnically disparate populations.

The association between ACE polymorphism and risk of colorectal cancer in a Chinese population

OBJECTIVES

Angiotensin I-converting enzyme (ACE) plays crucial roles not only in the regulation of circulatory homeostasis but also in the pathology of carcinomas. An insertion-deletion (I/D) polymorphism in intron 16 of ACE gene was identified to be functional. We aimed to investigate the association between ACE I/D polymorphism and risk of colorectal cancer (CRC).

DESIGN AND METHODS

Using genomic DNA from 241 CRC patients and 299 control subjects, we genotyped the ACE I/D polymorphism using a polymerase chain reaction analysis.

RESULTS

We found that patients carrying the D allele were associated with an increased risk of developing poorly differentiated cancer and metastasis compared with those carrying the I allele (OR=1.54, 95%CI, 1.04-2.28; OR=1.56, 95%CI, 1.08-2.26, respectively), although no significant association was observed between cases and controls in overall analysis.

CONCLUSIONS

These findings indicate that the ACE I/D polymorphism is likely to play a role in CRC progression.

Angiotensinogen t235 and angiotensin-converting enzyme insertion/deletion polymorphisms associated with the development of posttransplantation diabetes mellitus in renal allograft recipients

BACKGROUND

Genetic polymorphisms of the renin-angiotensin system (RAS) have been reported to play an important role in the pathogenesis of diabetes mellitus and hypertension. In addition, a close association has been reported between RAS and the progression of both diabetes and hypertension. But the role of RAS on the development of posttransplantation diabetes mellitus (PTDM) is not known. For this purpose we investigated the association of polymorphisms in the genes for angiotensin-converting enzyme (ACE) and angiotensinogen (AGT) with the development of PTDM.

METHODS

Genotyping for ACE insertion/deletion (I/D) and AGT M235T polymorphisms was performed in 50 patients who underwent renal transplantation during a 5-year period. Group 1 consisted of 23 recipients who developed PTDM and group 2 consisted of 27 recipients that did not have PTDM.

RESULTS

Of 50 patients, 13 (26%) showed the ACE DD, 21 (42%) the ACE ID, and 16 the ACE II genotype. The frequencies of AGT MM, AGT MT, and AGT TT were 0, 54%, and 46%, respectively. Compared with group 2, there were high frequencies of the AGT TT genotype in group 1 recipients (P<.001). In addition the ACE DD genotype was found significantly higher in group 1 patients compared with group 2 patients (P=.001).

CONCLUSION

The high frequencies of the AGT TT genotype and ACE DD genotype in recipients may contribute to the high prevalence of PTDM. Our data suggest a synergistic effect between the ACE and AGT polymorphism in the risk of PTDM, but to support this theory a larger patient group must be studied.

Renin-angiotensin system polymorphisms in relation to hypertension status and obesity in a Tunisian population

Essential hypertension (HTA) is the clinical expression of a disordered interaction between the genetic, physiological, and biochemical systems that under usual conditions maintain cardiovascular homeostasis. We studied the effects of the angiotensinogen M235T, angiotensin converting enzyme insertion/deletion (ACE I/D), and angiotensin II receptor 1 (AT1R) A1166C gene polymorphisms on the risk of HTA and to evaluate the relationship between these polymorphisms and obesity. We performed AGT, ACE and AGTR genotyping in 142 hypertensive patients and 191 control subjects using PCR-RFLP methods and PCR, respectively. The three polymorphisms were significantly associated with HTA. Individuals carrying the mutated TT of AGT, DD of ACE and CC of AT1R genotypes had an 1.67 (P = 0.032), 3.09 (P < 0.001) and 3.45 (P < 0.001)-fold increased risk of HTA. After adjustment for sex, smoking, diabetes, dyslipidemia, BMI, triglycerides and DD, TT and CC genotypes, BMI was independent risk factor of HTA (OR = 3.14; P < 0.001). An association of BMI with ACE gene polymorphism (P = 0.035), whereas no association with AGT and AT1R gene polymorphisms was obtained. The proportion of hypertensives is as high as 21.8 and 13.4% in the overweight and the obese DD group. The present study implies that the genotyping for the variants of RAS gene could in the future become an important part of the clinical process of risk identification for HTA.

Null association between ACE gene I/D polymorphism and diabetic nephropathy among multiethnic Malaysian subjects

BACKGROUND:

Wide inter-ethnic allelic variations of the Angiotensin Converting Enzyme (ACE) i nsertion-deletion (I/D) gene polymorphism were thought to be responsible for the conflicting gene–diabetic nephropathy disease association worldwide. We have investigated the genetic susceptibility of the ACE gene to diabetic nephropathy in the multiethnic Malaysian population.

MATERIALS AND METHODS:

A total of 137 healthy (control) and 256 diabetic subjects were recruited. The diabetic subjects were further subdivided according to their nephropathy status based on urinary albumin-creatinine ratio (ACR) and glomerular filtration rate (GFR). Triple primer polymerase chain reaction (PCR) was used for ACE I/D genotyping. Subsequently, populationwide genetic analysis and gene-disease association studies were performed.

RESULTS:

The genotype frequencies in all subgroups were in Hardy-Weinberg equilibrium. Similar allelic and genotypic frequency of ACE I/D gene polymorphism was observed between healthy controls versus pooled type 2 diabetes mellitus (T2DM) subjects, and normoalbuminuria versus microalbuminuria, macroalbuminuria and End Stage Renal Failure (ESRF) (P > 0.05). Neither ethnicity nor gender exerted any influence on the ACE I/D gene polymorphism (P > 0.05), with the exception of the Chinese ethnic group which exhibited a higher frequency of ID genotype (P = 0.042). A multinomial logistic regression model showed that predictive factors including age, systolic blood pressure (SBP), high density lipoprotein (HDL) and glycosylated hemoglobin (HbA1C) were independently associated with diabetic nephropathy, in that order.

CONCLUSION:

The I/D polymorphism of the ACE gene is not significantly associated with both T2DM and/or diabetic nephropathy in this Malaysian population regardless of ethnicity and gender.

Pharmacogenetic association of hypertension candidate genes with fasting glucose in the GenHAT Study

BACKGROUND

Several clinical studies report increased risk of diabetes mellitus with pharmacologic treatment for hypertension (HTN). HTN genes may modify glycemic response to antihypertensive treatment.

METHOD

The current study examined the association of 24 single nucleotide polymorphisms (SNPs) in 11 HTN candidate genes with fasting glucose measured at 2, 4, and 6 years after treatment initiation. The study sample included participants free of diabetes at baseline in the Genetics of Hypertension Associated Treatment (GenHAT) study (N = 9309). GenHAT participants were randomized to receive treatment with a diuretic (chlorthalidone), calcium channel blocker (amlodipine), or angiotensin-converting enzyme (ACE) inhibitor (lisinopril). Mixed models for repeated measures were employed to test for gene and pharmacogenetic associations with fasting glucose during follow-up.

RESULTS

Fasting glucose at year 2 increased on average 6.8, 4.8 and 3.0 mg/dl from baseline in the chlorthalidone, amlodipine and lisinopril groups, respectively. Carrying the I allele (rs1799752) of the ACE I/D polymorphism was associated with lower fasting glucose levels (P = 0.02). Additionally, an ACE promoter polymorphism (-262, rs4291) was associated with lower fasting glucose for the model AA/AT vs. TT, which remained significant after correction for multiple testing (P = 0.001). Finally, a SNP in the α-subunit of the amiloride-sensitive epithelial sodium channel (SCNN1A, rs2228576) modified the association of amlodipine vs. chlorthalidone treatment with fasting glucose (P < 0.001).

CONCLUSION

Further examination of these genes and their relationships with cardiometabolic disease could foster development of pharmacogenetic guidelines aimed to prevent increases in fasting glucose during antihypertensive treatment.

Genotypic interactions of renin-angiotensin system genes with diabetes type 2 in a Tunisian population

AIMS

To explore the role of genetic variants of angiotensinogen (AGT M235T), angiotensin-converting enzyme (ACE I/D), and angiotensin type 1 receptor (AT1R A1166C) as predictors of diabetes risk and to examine their combined effects on type 2 diabetes mellitus (T2DM) patients.

MAIN METHODS

One hundred and fourteen T2DM patients were compared to 175 healthy controls with similar age and sex.

KEY FINDINGS

The genotypic frequencies for all three genes alone were significantly associated with increased risk of developing diabetes. Logistic regression analysis of classic coronary risk factors and the genetic polymorphisms demonstrated that hypertension and ACE DD genotype were the most significant contributors to T2DM. For the renin-angiotensin system (RAS) genes, the risk of T2DM in individuals with one risk genotype was 1.9 (95%CI: 1.1-3.0, p=0.017) higher than those with zero risk genotype. Individuals who carried two risk genotypes had a 4.0 (95%CI 1.7-9.4, p=0.001) times higher risk of T2DM than those who did not carry any risk genotypes of the RAS genes. Most interestingly, the risk of T2DM for individuals with three risk genotypes was 26.2 (95%CI: 5.8-117.9, p<0.001) higher than those with zero risk genotype.

SIGNIFICANCE

The results of the present study imply that genotyping of renin-angiotensin system genes could become an important part of the clinical process of risk identification for T2DM in Tunisian population.

Angiotensin converting enzyme D allele is associated with an increased risk of type 2 diabetes: evidence from a meta-analysis

Associations of angiotensin converting enzyme gene (ACE) insertion/deletion (I/D) polymorphism with type 2 diabetes (T2D) have been inconsistent with both positive, null and negative results. We thereby performed a meta-analysis from all English-published reports to examine ACE I/D polymorphism in association with T2D risk. Case-control studies were identified from MEDLINE, EMBASE and Web of Science as of Dec 10, 2009. A total of 14 studies with 1985 patients with T2D and 4602 controls were finally identified. Random-effects model was applied irrespective of between-study heterogeneity. Study quality was assessed in duplicate. Compared with ACE I allele, presence of D allele conferred a significant increased risk for T2D (OR=1.33; 95% CI, 1.10-1.61; p=0.003). This trend was potentiated after comparing homozygotes of D allele with I allele with a 90% increased risk (p=0.0008). Carriers of D allele had a moderate increased risk for T2D compared with the II genotype carriers (OR=1.34; 95% CI, 1.04-1.72; p=0.02), whereas under recessive model this effect was significantly enhanced (OR=1.73; 95% CI, 1.26-2.38; p=0.0008). Subgroup analyses indicated significant association for population-based study design only, as well as among populations from Africa and Europe ancestries rather than from Asia ancestry. No publication bias was observed using the fail-safe number at the level of 0.05. Our results demonstrated that ACE D allele was significantly associated with an increased risk of T2D, and this effect appeared to be additive. Moreover, this association was more prominent for population-based studies and among Africans and Caucasians.

Angiotensin-converting enzyme gene polymorphism is associated with type 2 diabetes: a meta-analysis

The association of angiotensin-converting enzyme gene polymorphism with type 2 diabetes was investigated in many studies with conflicting results. To clarify this conflict, we performed a meta-analysis on recent previous reports on ACE gene polymorphism and its correlation to type 2 diabetes. A total of 15,166 subjects from 24 studies were included in this meta-analysis. Summary odds ratios (ORs) were estimated. Potential sources of heterogeneity and bias were explored. The D variant was associated with a 14% increased risk of T2D relative to the I variant (OR 1.14; 95% CI: 1.04-1.24). In subgroup analysis, Caucasian and East Asians showed significant association. No association was found in the Turkish groups. No publication bias was observed in this meta-analysis by using the Egger method (tau = 1.63, P = 0.12), as well as the Begg's test (z = 1.66, P = 0.10). Cumulative meta-analysis for the allelic contrast showed a trend of association as information accumulated. These data suggested that the variant of ACE I/D had a moderate positive association with type 2 diabetes.

DD genotype of angiotensin-converting enzyme in type 2 diabetes mellitus with renal disease in Mexican Mestizos

AIM

The DD genotype of angiotensin-converting enzyme (ACE) has been suggested as a major contributor of diabetic nephropathy in several populations. The purpose of the present study was to determine whether micro/macroalbuminuria is associated with ACE insertion/deletion (I/D) polymorphism in Mexican Mestizos with type 2 diabetes mellitus.

METHODS

A total of 435 patients with type 2 diabetes mellitus, of whom 233 had albuminuria, were characterized for the ACE I/D polymorphism by the polymerase chain reaction method.

RESULTS

Clinical and biochemical characteristics and frequencies according to DD, ID and II genotypes in patients with and without albuminuria showed no significant differences. However, only females with micro/macroalbuminuria showed higher frequency of a DD genotype than those without albuminuria (27.9%, 21.2% and 10.5%, respectively; P <or= 0.044). In addition, female patients with macroalbuminuria without dialysis showed no significant differences with patients undergoing dialysis.

CONCLUSION

The ACE DD genotype is a risk factor for the development of renal disease in Mexican Mestizo females with type 2 diabetes, indicating a possible DD genotype-associated sex effect in renal disease.

Lack of genetic association between the angiotensin-converting enzyme gene insertion/deletion polymorphism and longevity in a Han Chinese population

Introduction. The insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene has been reported to associate with human longevity. However, little information is available in a Han Chinese longevity population.Therefore, we investigated the association of the ACE gene insertion/ deletion polymorphism with longevity in a Han Chinese population.

Materials and methods. We compared the distribution of ACE insertion/deletion genotype and allele frequencies in two groups: a longevity group (399 subjects) aged over 90 years and a control group (302 subjects) aged less than 60 years.

Results. No difference in genotype and allele frequencies of the ACE gene insertion/deletion polymorphism was observed between the longevity group and the control group.When adjusting for gender, the difference between the longevity group and the control group was also not significant regarding the frequencies of the genotypes (male, p=0.994 and female, p=0.797) as well as allele frequencies (male, p=0.969 and female, p=0.884).

Conclusions. No association of the ACE gene insertion/deletion polymorphism with longevity was observed in our Han Chinese population.

Association of insertion/deletion polymorphism of angiotensin-converting enzyme gene with essential hypertension and type 2 diabetes mellitus in Malaysian subjects

INTRODUCTION

The deletion (D) allele of the angiotensin-converting enzyme (ACE) gene has been studied in various populations in relation to hypertension (HTN) and type 2 diabetes mellitus (T2DM) with contradictory results. This study sought to determine the association of insertion (I)/D polymorphism of the ACE gene in hypertensive and T2DM subjects in a Malaysian population.

MATERIALS AND METHODS

A total of 260 subjects consisting of 65 HTN, 60 T2DM, 65 T2DM with HTN and 70 controls were recruited. Genotyping was performed by polymerase chain reaction initially and mistyping of DD genotypes was performed with an insertion-specific primer.

RESULTS

The frequency for II, ID and DD genotypes of the ACE gene was 36.92%, 52.31% and 10.77% in HTN, 40.00%, 41.67% and 18.33% inT2DM, 30.77%, 53.85% and 15.38% inT2DM with HTN and 57.14%, 40.00% and 2.86% in controls, respectively. The frequency for the D allele was 36.92% in HTN, 39.17% in T2DM and 42.31% in T2DM with HTN compared to 22.86% in controls. The genotype and allele frequency of the ACE gene polymorphism differed significantly in patients when compared to controls (p < 0.05).

CONCLUSION

The D allele of the ACE gene is associated with essential HTN and T2DM in Malaysian subjects.

Evolutionary changes of astroglia in Elasmobranchii comparing to amniotes: a study based on three immunohistochemical markers (GFAP, S-100, and glutamine synthetase)

This paper supplements former studies on elasmobranch species with an immunohistochemical investigation into glutamine synthetase and S-100 protein, in addition to GFAP, and extends its scope to the representatives of almost every group of Elasmobranchii: squalomorph sharks, galeomorph sharks, skates (Rajiformes) and rays (Torpediniformes and Myliobatifomes). More glial elements were labeled by S-100 protein, and even more so by using glutamine synthetase immunostaining than by GFAP: more astrocytes (mainly non-perivascular ones) were detected in the telencephalon of sharks, skates and rays. Only the markers S-100 and glutamine synthetase, but not GFAP, characterized the Bergmann-glia of skates and rays and astrocyte-like non-ependymal cells in Squalus acanthias. Another squalomorph shark species, Pristiophorus cirratus, however, had GFAP immunopositive astrocytes. Of all the species studied, the greatest number of GFAP positive astrocytes could be observed in Mobula japanica (order Myliobatiformes), in each major brain part. According to anatomical location, perivascular glia comprised varied types, including even a location in Mobula, which can also be found in mammals. Remnants of radial glia were found in confined areas of skates, less so in rays. In the rhombencephalon and in the spinal cord modified ependymoglia predominated in every group. In conclusion, there was no meaningful difference between the astroglial architectures of squalomorph and galeomorph sharks. The difference in the astroglial structure between sharks and batoids, however, was confined to the telencephalon and mesencephalon, and did not take place in the rhombencephalon, the latter structure being quite similar in all the species studied. The appearance of astrocytes in the relatively thin-walled shark telencephalon, however, indicates that the brain thickening promoted the preponderance of astrocytes rather than their appearance itself. Although the evolutionary changes of astroglia had some similarities in Elasmobranchii and Amniota, there was one meaningful difference: in Elasmobranchii astrocytes did not prevail in conservative brain regions as they did in the progressive brain regions.

Association of APOE (Hha1) and ACE (I/D) gene polymorphisms with type 2 diabetes mellitus in North West India

Familial and epidemiological studies have shown that genetic factors play a role in the development and progression of type 2 diabetes mellitus (T2DM). Asian Indians have shown an increasing prevalence of T2DM. Apolipoprotein E (APOE) and Angiotensin-1 converting enzyme (ACE) I/D polymorphisms have been associated with T2DM. This study examined the association of APOE and ACE genes with T2DM patients of Punjab, India. APOE (HhaI) and ACE (I/D) genotypes analysed by polymerase chain reaction were available from 90 patients and 97 random healthy controls. All loci and populations are in Hardy-Weinberg equilibrium. There is no significant association of APOE vis-à-vis T2DM, however APOE*4 allele frequency is low in diabetics (3.9% and 8.8%). DD genotype and *D allele of ACE are associated with T2DM (OR=1.90, p<0.05, and OR=1.58, p<0.05, respectively). Recessive and multiplicative mode of inheritance for *D allele provided the strongest support for the association. Height, weight and BMI did not reveal any significant association with APO or ACE. DD-33 and ID-23 combinations (ACE-APOE) showed higher odds of 2.01 and 2.14, respectively. ACE but not APOE polymorphism is positively associated with T2DM in Indian population, however, the synergistic effects of DD-33 and ID-23 are also evident.

Clinical and Genetic Risk Factors for Posttransplant Diabetes Mellitus in Adult Renal Transplant Recipients Treated with Tacrolimus

BACKGROUND

The present study investigated the incidence of posttransplant diabetes mellitus (PTDM) and calculated the risk of developing PTDM under a tacrolimus-based immunosuppression based on clinical characteristics, tacrolimus pharmacokinetics, and genetic polymorphisms related to tacrolimus pharmacokinetics or diabetes mellitus.

METHODS

Seventy nondiabetic adult kidney recipients were studied. Patients with continuous high plasma glucose levels, over 6.5 mg/dl of hemoglobin A1c, or requiring insulin and/or oral antidiabetic agents for more than 3 months after transplantation 6 months postoperatively were diagnosed as having PTDM. Twelve genomic polymorphisms were assessed.

RESULTS

Six months after transplantation, 10 recipients (14.3%) developed PTDM. Positive risk factors were age (P=0.019) and body mass index (P=0.038). There were no significant differences in acute rejection rate, total steroid doses, tacrolimus pharmacokinetics or its related to genetic polymorphisms between the two groups. The frequency of PTDM was significantly higher in patients with the vitamin D receptor (VDR) TaqI t allele than in those with the TT genotype (P=0.013). On multivariate analysis, age over 50 years (odds ratio 9.28, P=0.003) and the presence of the VDR TaqI t allele (odds ratio 7.05, P=0.048) were correlated with the development of PTDM.

CONCLUSION

The incidence of PTDM was 14.3% in our cohort. Age over 50 years was a risk factor. The presence of the VDR TaqI t allele may also be a risk factor for PTDM, suggesting that genotyping of diabetes-related polymorphisms is a possible method of predicting a patient's risk for developing PTDM and would be a valuable asset in selecting appropriate immunosuppressive regimens for individuals.

Weight Gain after Liver Transplantation and the Insertion/Deletion Polymorphism of the Angiotensin-Converting Enzyme Gene

BACKGROUND

Subjects who carry the D allele of the angiotensin-converting enzyme (ACE) gene have higher plasma and tissue angiotensin II levels, possibly concurrent with the development of obesity. In transplant recipients, treatment with calcineurin antagonists would magnify these effects. The present study verifies whether the allelic variants of ACE are a factor involved in excess weight gain after liver transplantation.

METHODS

A consecutive series of 108 liver transplant recipients (73 males) were studied. Recipient ACE genotypes, determined by a polymerase chain reaction-based method, were related to body mass changes 1 year after transplant.

RESULTS

Body mass index (BMI) increased from the pretransplant value of 25.1+/-3.3 kg/m2 to 25.9+/-3.5 kg/m2 (P<0.005). The difference was mainly attributable to recipients carrying 1 D allele or more (N=88) in whom the BMI increased from 25.3+/-3.1 kg/m2 to 26.3+/-3.3 kg/m2 (P<0.005). A BMI of 25 kg/m or greater was measured in 30 of 45 deletion/deletion homozygotes and 25 of 43 insertion/deletion heterozygotes; in contrast, 14 of 20 insertion/insertion homozygotes had a normal body mass (P<0.01). Among patients with normal body mass pretransplant (N=56), none of 13 insertion/insertion homozygotes reached a BMI value 25 kg/m or greater posttransplant (P<0.005). At multivariate analysis, pretransplant body mass and carriage of 1 D allele or more were independent predictors of body mass gain greater than 2 kg/m.

CONCLUSIONS

Carriage of the D allele of the ACE gene is a strong, independent risk factor for excess weight gain after liver transplantation.