The relationship between ACE/AGT gene polymorphisms and the risk of diabetic retinopathy in Chinese patients with type 2 diabetes

No Association of Angiotensin-Converting Enzyme Insertion/Deletion (ACE I/D) Gene Polymorphism in the Susceptibility to Diabetic Retinopathy in Type 2 Diabetes Mellitus Patients: An Updated Meta-Analysis

Diabetic retinopathy (DR) is a complex and multifactorial pathology encompassing environmental, metabolic, and polygenic influences. Among the genes possibly involved in the development and progression of DR, the Angiotensin I-converting enzyme (ACE) gene stands out, which presents an insertion (I) or deletion (D) polymorphism of a 287 bp Alu repetitive sequence in intron 16. Thus, this study aimed to perform a systematic review with meta-analysis to elucidate the relationship between the ACE gene (I/D) polymorphism (rs1799752) and the development and progression of DR in type 2 diabetic patients. PubMed/MEDLINE, Embase, Web of Science, and Scopus databases were systematically searched to retrieve articles that investigated the association between ACE gene (I/D) polymorphism in DR patients. Sixteen articles were included in the systematic review. The results describe no significant association between the polymorphism and DR risk (OR = 1.12; CI = 0.96-1.31; and p = 0.1359) for genotypic analysis by the dominant model (II vs. ID+DD). Moreover, we also observed no significant association between the D allele on the allele frequency analysis (I vs. D) and the DR risk (OR = 1.10; CI = 0.98-1.23; and p = 0.1182). Forest plot analysis revealed that the discrepancy between previous studies most likely arose from variations in their sample sizes. In conclusion, I/D polymorphism appears to be not involved in the susceptibility to and progression of the DR in type 2 diabetic patients.

Association of gene polymorphisms of ACE, AGT, and ARNT-like protein 1 with susceptibility to gestational diabetes

Background and aims

Gestational diabetes mellitus is well-defined as glucose intolerance first documented during pregnancy. In this study, we examined the possible associations between I/D polymorphism of the angiotensin-converting enzyme gene, the M235T variant of angiotensinogen gene, and the rs7950226 polymorphism of the ARNT-like protein-1 (BMAL1) gene and the risk for diabetes in Egyptian pregnant women.

Subjects and methods

This study recruited 160 gestational diabetes cases and 165 controls. Genomic DNA was derived from peripheral blood leukocytes and ACE gene (I/D) genotyping was performed using the method of polymerase chain reaction and the polymerase chain reaction-based restriction fragment length polymorphism was used for identifying the M235T variant of AGT gene and the rs7950226 polymorphism of the BMAL1.

Results

The II, ID, and DD genotypes of the ACE gene have significant differences in cases compared to controls (P = 0.000 and X2 = 81.77). The M235T polymorphism of the AGT gene was increased with gestational diabetes risk. Furthermore, the AA genotype of the BMAL1 rs7950226 gene was significantly related to the gestational diabetes risk (P = 0.000 and X2 = 52.82). Furthermore, the allele frequencies of the three variants have significant variances between cases and control.

Conclusion

This study suggested significant associations between ACE (DD), AGT (TT), and BMAL1 rs7950226 (AA) gene polymorphisms with gestational diabetes susceptibility and there was a possibility to identify that II + MM + GG as protective haplotypes and DD + TT + AA as risk haplotypes for gestational diabetes.

Genetics of Diabetic Retinopathy, a Leading Cause of Irreversible Blindness in the Industrialized World

Diabetic retinopathy (DR) is a chronic complication of diabetes and a leading cause of blindness in the industrialized world. Traditional risk factors, such as glycemic control and duration of diabetes, are unable to explain why some individuals remain protected while others progress to a more severe form of the disease. Differences are also observed in DR heritability as well as the response to anti-vascular endothelial growth factor (VEGF) treatment. This review discusses various aspects of genetics in DR to shed light on DR pathogenesis and treatment. First, we discuss the global burden of DR followed by a discussion on disease pathogenesis as well as the role genetics plays in the prevalence and progression of DR. Subsequently, we provide a review of studies related to DR’s genetic contribution, such as candidate gene studies, linkage studies, and genome-wide association studies (GWAS) as well as other clinical and meta-analysis studies that have identified putative candidate genes. With the advent of newer cutting-edge technologies, identifying the genetic components in DR has played an important role in understanding DR incidence, progression, and response to treatment, thereby developing newer therapeutic targets and therapies.

Association of angiotensin-converting enzyme insertion/deletion (ACE I/D) and angiotensinogen (AGT M235T) polymorphisms with the risk of obesity in a Tunisian population

Objective:

This study aims to determine whether genetic variants in ACE I/D and AGT M235T are associated with overweight-obesity and body mass index (BMI) in a Tunisian population.

Methods:

We designed an age- and sex-matched case-control study. The height and weight were measured and BMI was calculated. A total of 259 overweight-obese patients and 369 healthy controls were genotyped for the ACE I/D and AGT M235T genes using polymerase chain reaction and restriction fragment length polymorphism.

Results:

ACE I/D and AGT M235T genes were associated with BMI, waist circumference and overweight-obesity (p⩽0.001). In an additive model, the I and the M alleles in ACE and AGT variants, respectively, were associated with a lower BMI: –1.45 and −2.29 units, respectively. ACE I/D genotypes were associated with dyslipidemia; AGT M235T genotypes with dyslipidemia and total cholesterol.

Conclusion:

These data suggest that variations in ACE I/D and AGT M235T affect the risk of overweight-obesity, BMI and dyslipidemia, and could point to a key molecular pathway of metabolic syndrome and its related comorbidities.

Association between angiotensinogen T174M polymorphism and the risk of diabetic nephropathy: A meta-analysis

Objective:

Although the angiotensinogen (AGT) gene T174M polymorphism has been implicated in the pathogenesis of diabetic nephropathy (DN), study results have been inconsistent. The present meta-analysis was conducted to determine the correlation of AGT T174M polymorphism with DN.

Methods:

We retrospectively extracted relevant studies from Embase as well as PubMed databases. Additionally, a fixed- or random-effects model was employed for calculation of pooled odds ratio (OR) along with 95% confidence interval (CI).

Results:

In total, we identified six studies (1179 cases and 927 controls) regarding the AGT gene T174M polymorphism. The pooled ORs for the association between the AGT T174M polymorphism and DN risk were not statistically significant under all genetic models (M vs T: OR = 1.22, 95% CI = 0.84–1.75; MM vs TT: OR = 1.94, 95% CI = 0.93–4.04; MT vs TT: OR = 1.11, 95% CI = 0.76–1.63; the dominant model: OR =1.19, 95% CI = 0.80–1.77; the recessive model: OR = 1.94, 95% CI = 0.93–4.03). Subgroup analyses based on the type of race showed the M allele of the AGT T174M polymorphism increased DN risk in Asians, but not in Caucasians.

Conclusions:

Our study indicated that the T174M polymorphism in the AGT gene was associated with DN in Asians.