VEGF genetic polymorphisms may contribute to the risk of diabetic nephropathy in patients with diabetes mellitus: a meta-analysis

Metabolic Syndrome and Tendon Disease: A Comprehensive Review

Metabolic syndrome (MS) is a multifaceted pathological condition characterized by the atypical accumulation of various metabolic components such as central obesity or excess weight, hyperlipidemia, low-density lipoprotein (LDL), hypertension, and insulin resistance. Recently, MS has been recognized as a notable contributor to heart and circulatory diseases. In addition, with increasing research, the impact of MS on tendon repair and disease has gradually emerged. Recent studies have investigated the relationship between tendon healing and diseases such as diabetes, dyslipidemia, obesity, and other metabolic disorders. However, diabetes mellitus (DM), hypercholesterolemia, obesity, and various metabolic disorders often coexist and together constitute MS. At present, insulin resistance is considered the major pathological mechanism underlying MS, central obesity is regarded as the predominant factor responsible for it, and dyslipidemia and other metabolic diseases are known as secondary contributors to MS. This review aims to evaluate the current literature regarding the impact of various pathological conditions in MS on tendon recovery and illness, and to present a comprehensive overview of the effects of MS on tendon recovery and diseases, along with the accompanying molecular mechanisms.

Association of 18bp insertion/deletion polymorphism, at -2549 position of VEGF gene, with diabetic vascular complications in type 2 diabetes mellitus

PURPOSE

Diabetes mellitus type 2 (T2DM) and its vascular complications are a serious world health problem. For this reason it is important to look for new diabetes complication risk factors. The aim of this study was to determine whether 18-bp insertion/deletion (I/D) polymorphism at -2549 position of the vascular endothelial growth factor (VEGF) gene is associated with diabetic vascular complications (DVC).

MATERIAL AND METHODS

Caucasian subjects (n = 100) with T2DM were recruited for this study. Genotyping of the VEGF gene I/D polymorphism was done by the polymerase chain reaction (PCR) method. The results were correlated with laboratory and clinical data.

RESULTS

In our population heterozygous of the VEGF gene polymorphism was observed most frequently (57%). DVC were observed in 53 patients. Heterozygous T2DM patients significantly more often suffered from heart failure (HF) and stroke (p = 0.05). Amongst all the DVC, D allele of the VEGF polymorphism had a significantly increased risk of diabetic retinopathy (DR) (OR = 1.31; p = 0.033) irrespective of the duration of diabetes, BMI, the glycemia control expressed by HbA1c, renal function, lipid values or applied treatment. The studied polymorphism did not correlate with coronary heart disease, peripheral vascular disease, cardiovascular death, diabetic kidney disease or applied treatment.

CONCLUSIONS

The multivariate logistic regression analysis showed that the D allele in the promoter region of the VEGF gene is an independent risk factor of DR irrespective of other laboratory and clinical variables in T2DM patients. Our study suggests that I/D allele in the studied gene is associated with HF and strokes.

Association of VEGFA variants with altered VEGF secretion and type 2 diabetes: A case-control study

BACKGROUND

Vascular endothelial growth factor (VEGF) contributes to type 2 diabetes (T2DM) pathogenesis, and genetic variations in VEGFA gene were suggested to influence VEGF secretion and T2DM pathogenesis.

AIM

To evaluate the association of specific VEGFA variants with altered VEGF levels, and with T2DM among Tunisians.

SUBJECTS AND METHODS

A retrospective case-control study, performed on 815 T2DM patients, and 805 healthy controls. VEGF levels were measured by ELISA, genotyping of VEGFA variants was done by allelic exclusion method (real-time PCR).

RESULTS

MAF of rs1570360, rs2010963, rs25648, rs833068, rs3025036, and rs3025039 were significantly different between T2DM cases and controls. Increased T2DM risk was associated with rs699947, rs1570360, and rs3025020, while reduced T2DM risk was seen with rs1547651, rs2010963, rs25648, rs3025036, and rs3025039 genotypes, thus assigning T2DM susceptibility and protection, respectively. Reduced VEGF levels were associated with rs833061, rs2010963, and rs3025039 heterozygosity and rs3025036 major allele homozygosity in T2DM cases, while increased VEGF levels were seen in rs833070 homozygous major allele genotype. Both rs699947 and rs1570360 positively, while rs2010963 and rs3025036 negatively correlated with fasting glucose. In addition, rs699947 positively correlated with LDL-cholesterol, and rs3025039 positively correlated with diabetes duration, but negatively with HbA1c and serum triglycerides. Haploview analysis identified Block 1 containing 8 loci, and Block 2 with the remaining 3 loci. Haplotypes ACTGCCGG and AACGGCGA (Block 1) were negatively associated with T2DM, while haplotype CCC was positively and haplotype CGC (Block 2) were negatively associated with T2DM.

CONCLUSION

This study confirms the contribution of altered VEGF secretion, resulting from genetic variation in VEGFA gene into T2DM pathogenesis, hence supporting role for VEGFA as T2DM candidate locus.

Association between the vascular endothelial growth factor single nucleotide polymorphisms and diabetic retinopathy risk: A meta-analysis

BACKGROUND

The aim of the present study was to reveal the relationship between vascular endothelial growth factor (VEGF) single nucleotide polymorphisms (SNPs) and susceptibility to diabetic retinopathy (DR).

METHODS

A literature review was conducted (PubMed, Web of Science, Embase) to identify papers about VEGF SNPs and DR published up to 23 September 2015. The VEGF gene SNPs analyzed with regard to DR susceptibility were rs2010963 (G > C), rs833061 (T > C), rs699947 (C > A), rs3025039 (C > T) and rs1570360 (G > A). Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated, and meta-analyses were performed using fixed or random effects models.

RESULTS

Sixteen studies were included in the meta-analysis. Significant associations between the rs3025039 (C > T) polymorphism and increased DR risk were found in the allele model (T/C; pooled OR 1.60, 95% CI 1.07-2.41, P = 0.02), homozygote model (TT/CC; pooled OR 2.08, 95% CI 1.29-3.35, P = 0.003), heterozygote model (TC/CC; pooled OR 1.68, 95% CI 1.04-2.72, P = 0.04), dominant model (TT+TC/CC; pooled OR 1.72, 95% CI 1.06-2.80, P = 0.03), and recessive model (TT/TC+CC; pooled OR 1.80, 95% CI 1.12-2.90, P = 0.02). For rs833061, a significant association between VEGF SNPs and DR was found only in the allele model (C/T; pooled OR 6.34, 95% CI 2.10-19.14, P = 0.001).

CONCLUSIONS

The rs3025039 and rs833061 SNPs are most likely associated with an increased risk of DR. The T allele in rs3025039 and the C allele in rs833061 are associated with increased DR susceptibility.

Association between VEGF Gene Polymorphisms and In-Stent Restenosis after Coronary Intervention Treated with Bare Metal Stent

Background. In-stent restenosis (ISR) is the gradual narrowing of the vessel lumen after coronary stent implantation due to the increase in vascular smooth muscle cell proliferation. Vascular endothelial growth factor (VEGF) protein plays an important role in this process. Our aim was to analyze the association of single nucleotide polymorphisms of the VEGF gene (rs2010963 and rs6999447) with the occurrence of ISR after coronary artery bare metal stent (BMS) implantation. Methods. 205 patients with a history of BMS implantation and a repeated coronarography were prospectively enrolled. Patients were assigned to diffuse restenosis group (n = 105) and control group (n = 100) and VEGF genotypes were determined. Results. Diffuse ISR was significantly more frequently observed in patients with homozygous normal genotype of rs2010963 polymorphism, and this polymorphism was independently associated with diffuse ISR. Conclusions. RS2010963 is associated with higher incidence of development of diffuse coronary ISR in patients treated with BMS implantation.

Allele rs2010963 C of the VEGFA gene is associated with the decreased risk of primary varicose veins in ethnic Russians

Objective To study the association of polymorphisms rs699947, rs2010963, rs3025039 in the VEGFA gene region and rs1870377, rs2305949, rs2071559 in the VEGFR2 gene region with the risk of primary varicose veins in ethnic Russians. Methods Genotypes were determined by real-time PCR allelic discrimination. The case group consisted of 448 patients with primary varicose veins and the control group comprised 609 individuals without a history of chronic venous disease. Association was studied by logistic regression analysis. Results Allele rs2010963 C was associated with the decreased risk of varicose veins (additive model of inheritance: odds ratio = 0.73, 95% confidence interval = 0.59-0.91, P = 0.004). Conclusions Our results provide evidence that polymorphism rs2010963 located in the 5' untranslated region of the VEGFA gene can influence genetic susceptibility to primary varicose veins in Russians. Otherwise, it can be in linkage disequilibrium with another functional single nucleotide polymorphism that can alter the level of vascular endothelial growth factor A protein.

Association between Genetic Variants and Diabetes Mellitus in Iranian Populations: A Systematic Review of Observational Studies

INTRODUCTION

Diabetes mellitus as the most prevalent metabolic disease is a multifactorial disease which is influenced by environmental and genetic factors. In this systematic review, we assessed the association between genetic variants and diabetes/its complications in studies with Iranian populations.

METHODS

Google Scholar, PubMed, Scopus, and Persian web databases were systematically searched up to January 2014. The search terms were "gene," "polymorphism," "diabetes," and "diabetic complications"; nephropathy, retinopathy, neuropathy, foot ulcer, and CAD (coronary artery diseases); and Persian equivalents. Animal studies, letters to editor, and in vitro studies were excluded.

RESULTS

Out of overall 3029 eligible articles, 88 articles were included. We found significant association between CTLA-4, IL-18, VDR, TAP2, IL-12, and CD4 genes and T1DM, HNFα and MODY, haptoglobin, paraoxonase, leptin, TCF7L2, calreticulin, ERα, PPAR-γ2, CXCL5, calpain-10, IRS-1 and 2, GSTM1, KCNJ11, eNOS, VDR, INSR, ACE, apoA-I, apo E, adiponectin, PTPN1, CETP, AT1R, resistin, MMP-3, BChE K, AT2R, SUMO4, IL-10, VEGF, MTHFR, and GSTM1 with T2DM or its complications.

DISCUSSION

We found some controversial results due to heterogeneity in ethnicity and genetic background. We thought genome wide association studies on large number of samples will be helpful in identifying diabetes susceptible genes as an alternative to studying individual candidate genes in Iranian populations.

Identifying Common Genetic Risk Factors of Diabetic Neuropathies

Type 2 diabetes mellitus (T2DM) is a global public health problem of epidemic proportions, with 60-70% of affected individuals suffering from associated neurovascular complications that act on multiple organ systems. The most common and clinically significant neuropathies of T2DM include uremic neuropathy, peripheral neuropathy, and cardiac autonomic neuropathy. These conditions seriously impact an individual's quality of life and significantly increase the risk of morbidity and mortality. Although advances in gene sequencing technologies have identified several genetic variants that may regulate the development and progression of T2DM, little is known about whether or not the variants are involved in disease progression and how these genetic variants are associated with diabetic neuropathy specifically. Significant missing heritability data and complex disease etiologies remain to be explained. This article is the first to provide a review of the genetic risk variants implicated in the diabetic neuropathies and to highlight potential commonalities. We thereby aim to contribute to the creation of a genetic-metabolic model that will help to elucidate the cause of diabetic neuropathies, evaluate a patient's risk profile, and ultimately facilitate preventative and targeted treatment for the individual.