VEGF: a surrogate marker for peripheral vascular disease

Regular assessment of serum vascular endothelial growth factor levels to monitor POEMS syndrome

BACKGROUND

To investigate the utility of regular serum VEGF (sVEGF) levels assessment in the monitoring of POEMS syndrome.

METHODS

We retrospectively reviewed data of 30 patients with POEMS syndrome whose sVEGF was tested regularly every 6 months. sVEGF levels after treatment were measured and correlated with disability (Overall Neuropathy Limitations Scale, ONLS), clinical impairment (measured with the modified Clinical Response Evaluation Scale, mCRES), and relapse-free survival. The ability of sVEGF to predict disease flares during remission and refractory disease was also analysed.

RESULTS

Patients with normalised serum VEGF levels (< 1000 pg/ml) at 6 months showed prolonged relapse-free survival (at 3-year 94% for complete VEGF response, 57% partial, 0% none, p < 0.001) and greater later clinical improvement (median ΔmCRES complete VEGF response -5 vs partial -4, p = 0.019, and vs no VEGF response -2, p = 0.006). After remission, the sensitivity of 6-month sVEGF monitoring in predicting clinical relapse was 58% with a specificity of 100%. In patients refractory to treatment, the sensitivity in predicting further clinical worsening was 15%. In addition, in 25% of the patients in remission and 16% of those refractory to therapy, sVEGF levels only increased at the time of relapse.

CONCLUSIONS

Regular sVEGF assessment is a valid biomarker in the prediction of disease reactivation in POEMS syndrome and was particularly useful during the phase of remission.

Sex, Endothelial Cell Functions, and Peripheral Artery Disease

Peripheral artery disease (PAD) is caused by blocked arteries due to atherosclerosis and/or thrombosis which reduce blood flow to the lower limbs. It results in major morbidity, including ischemic limb, claudication, and amputation, with patients also suffering a heightened risk of heart attack, stroke, and death. Recent studies suggest women have a higher prevalence of PAD than men, and with worse outcomes after intervention. In addition to a potential unconscious bias faced by women with PAD in the health system, with underdiagnosis, and lower rates of guideline-based therapy, fundamental biological differences between men and women may be important. In this review, we highlight sexual dimorphisms in endothelial cell functions and how they may impact PAD pathophysiology in women. Understanding sex-specific mechanisms in PAD is essential for the development of new therapies and personalized care for patients with PAD.

Endothelial cell dysfunction: Implications for the pathogenesis of peripheral artery disease

Peripheral artery disease (PAD) is caused by occluded or narrowed arteries that reduce blood flow to the lower limbs. The treatment focuses on lifestyle changes, management of modifiable risk factors and vascular surgery. In this review we focus on how Endothelial Cell (EC) dysfunction contributes to PAD pathophysiology and describe the largely untapped potential of correcting endothelial dysfunction. Moreover, we describe current treatments and clinical trials which improve EC dysfunction and offer insights into where future research efforts could be made. Endothelial dysfunction could represent a target for PAD therapy.

Circulating Biomarkers in Lower Extremity Artery Disease

Lower extremity artery disease (LEAD), a chronic condition with disturbed lower extremity circulation due to narrowing of the arteries, is predominantly caused by atherosclerosis and is associated with the presence of cardiovascular risk factors and an increased risk of cardiovascular events. LEAD is prevalent among older individuals and predicted to rise with the ageing population. In progressive disease, the patient experiences symptoms of ischaemia when walking and, in advanced critical limb-threatening ischaemia, even at rest. However, LEAD is asymptomatic in most patients, delaying diagnosis and treatment. In this setting, circulating biomarkers may facilitate earlier diagnosis in selected individuals. This review provides a broad overview of the circulating biomarkers investigated to date in relation to LEAD and discusses their usefulness in clinical practice.

VASCULAR-1 and VASCULAR-2 as a New Potential Angiogenesis and Endothelial Dysfunction Markers in Peripheral Arterial Disease

The quotient of concentrations concerning the key proangiogenic factor, that is, the vascular endothelial growth factor (VEGF-A) and the angiogenesis inhibitor, namely, its soluble receptors (sVEGFR-1 or sVEGFR-2), seems to reflect increased hypoxia and intensity of compensation angiogenesis. Therefore, it can be an ischemic and endothelial dysfunction marker reflected in intermittent claudication (IC) or critical limb ischemia (CLI) in patients with symptomatic peripheral arterial disease (PAD). The main objective of this study was to evaluate the levels of VEGF-A/sVEGFR-1 and VEGF-A/sVEGFR-2—presented using a novelty acronym VASCULAR-1 and VASCULAR-2—in patients with IC and CLI, as well as displayed in 4 classes of severity of PAD. VASCULAR-1 and VASCULAR-2 were calculated using the plasma of venous blood sampled from 80 patients with IC (n = 65) and CLI (n = 15) and the control group (n = 30). Patients with CLI were reported to have a slightly higher index of VASCULAR-1 and double VASCULAR-2 levels as compared to patients with IC (P = nonsignificant), and these markers were significantly higher than controls (P < .01 and P < .01, respectively). VASCULAR-2 levels were observed to have an increasing tendency in the subsequent degrees of PAD severity according to the Fontaine classification (P = .02). In view of the need to consider the role of the proangiogenic and antiangiogenic factor in the assessment of the so-called “angiogenic potential,” VASCULAR-1 ratio and VASCULAR-2 ratio may be a new useful biomarker of limb ischemia in patients with IC and CLI. However, this requires further studies and evidence on a very large group of patients with PAD.

Early Prediction of Persistent Organ Failure by Circulating Endothelial Progenitor Cells in Patients With Acute Pancreatitis

INTRODUCTION

Increased circulating endothelial progenitor cells (cEPC) have been observed in patients with vascular injury associated with sepsis and acute lung injury. However, a role for cEPC in severe acute pancreatitis (SAP) remains unclear. We therefore conducted a prospective study to study whether the quantities of cEPC can predict persistent organ failure (POF) in patients with predicted SAP.

METHODS

A total of 42 predicted SAP patients who were admitted within 24 h after symptom onset and 10 healthy control subjects were enrolled in our study. The proportions of cEPC were analyzed based on flow cytometry simultaneously. Vascular endothelial growth factor (VEGF) levels were measured by enzyme-linked immunosorbent assay.

RESULTS

The percentage of cEPC was significantly higher in patients with predicted SAP compared with healthy controls. Similarly, the levels of VEGF in peripheral blood were also significantly higher in predicted SAP patients than in the controls. Notably, patients with POF had lower proportion of cEPC compared with patients with transient organ failure (TOF). In contrast, patients with POF had a significantly higher level of VEGF compared with TOF. Of note, the percentages of cEPC were significantly inversely correlated with disease severity scores. More importantly, cEPC showed an excellent discriminative power for predicting POF among predicted SAP patients, whereas plasma VEGF and disease severity scores showed moderate accuracy in predicting future POF.

CONCLUSIONS

Peripheral EPC as a novel biomarker is elevated and may aid to predict the development of POF in patients with predicted SAP.

Coexistence of proangiogenic potential and increased MMP-9, TIMP-1, and TIMP-2 levels in the plasma of patients with critical limb ischemia

The objective of this study was to assess the angiogenic potential expressed as a quotient of vascular endothelial growth factor A (VEGF-A), as an indicator of proangiogenic activity, and the circulating receptors (soluble VEGF receptor protein R1 (sVEGFR-1) and sVEGFR-2), as indicators of the effect of angiogenic inhibition, depending on the concentrations of matrix metalloproteinase 2 (MMP-2) and MMP-9 and their tissue inhibitor 1 (TIMP-1) and TIMP-2 in the plasma of patients with lower extremity artery disease (LEAD). These blood parameters in patients with intermittent claudication (IC) and critical limb ischemia (CLI) were compared for select clinical and biochemical features. Stimulation of angiogenesis in the plasma of individuals with LEAD was evident as indicated by the significant increase in VEGF-A concentration along with reduced inhibition depending on circulating receptors sVEGFR-1 and sVEGFR-2. Critical ischemia was associated with higher VEGF-A, MMP-9, TIMP-1, and TIMP-2 concentrations than in the case of IC.

Heat therapy vs. supervised exercise therapy for peripheral arterial disease: a 12-wk randomized, controlled trial

Peripheral arterial disease (PAD) is characterized by lower limb atherosclerosis impairing blood supply and causing walking-induced leg pain or claudication. Adherence to traditional exercise training programs is poor due to these symptoms despite exercise being a mainstay of conservative treatment. Heat therapy improves many cardiovascular health outcomes, so this study tested if this was a viable alternative cardiovascular therapy for PAD patients. Volunteers with PAD were randomized to 12 wk of heat ( n = 11; mean age 76 ± 8 yr, BMI 28.7 ± 3.5 kg/m2, 4 females) or exercise ( n = 11; 74 ± 10 yr, 28.5 ± 6.8 kg/m2, 3 females). Heat involved spa bathing at ∼39°C, 3–5 days/wk for ≤30 min, followed by ≤30 min of callisthenics. Exercise involved ≤90 min of supervised walking and gym-based exercise, 1–2 days/wk. Following the interventions, total walking distance during a 6-min walk test increased (from ∼350 m) by 41 m (95% CI: [13, 69], P = 0.006) regardless of group, and pain-free walking distance increased (from ∼170 m) by 43 m ([22, 63], P < 0.001). Systolic blood pressure was reduced more following heat (−7 mmHg, [−4, −10], P < 0.001) than following exercise (−3 mmHg, [0, −6], P = 0.078), and diastolic and mean arterial pressure decreased by 4 mmHg in both groups ( P = 0.002). There were no significant changes in blood volume, ankle-brachial index, or measures of vascular health. There were no differences in the improvement in functional or blood pressure outcomes between heat and exercise in individuals with PAD.

NEW & NOTEWORTHY Heat therapy via hot-water immersion and supervised exercise both improved walking distance and resting blood pressure in peripheral arterial disease (PAD) patients over 12 wk. Adherence to heat therapy was excellent, and the heat intervention was well tolerated. The results of the current study indicate that heat therapy can improve functional ability and has potential as an effective cardiovascular conditioning tool for individuals with PAD.

Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/heat-therapy-vs-exercise-in-peripheral-arterial-disease/ .

VEGF-A inhibits agonist-mediated Ca2+ responses and activation of IKCa channels in mouse resistance artery endothelial cells

KEY POINTS

Prolonged exposure to vascular endothelial growth factor A (VEGF-A) inhibits agonist-mediated endothelial cell Ca²⁺ release and subsequent activation of intermediate conductance Ca²⁺ -activated K⁺ (IK_Ca ) channels, which underpins vasodilatation as a result of endothelium-dependent hyperpolarization (EDH) in mouse resistance arteries. Signalling via mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) downstream of VEGF-A was required to attenuate endothelial cell Ca²⁺ responses and the EDH-vasodilatation mediated by IK_Ca activation. VEGF-A exposure did not modify vasodilatation as a result of the direct activation of IK_Ca channels, nor the pattern of expression of inositol 1,4,5-trisphosphate receptor 1 within endothelial cells of resistance arteries. These results indicate a novel role for VEGF-A in resistance arteries and suggest a new avenue for investigation into the role of VEGF-A in cardiovascular diseases.

ABSTRACT

Vascular endothelial growth factor A (VEGF-A) is a potent permeability and angiogenic factor that is also associated with the remodelling of the microvasculature. Elevated VEGF-A levels are linked to a significant increase in the risk of cardiovascular dysfunction, although it is unclear how VEGF-A has a detrimental, disease-related effect. Small resistance arteries are central determinants of peripheral resistance and endothelium-dependent hyperpolarization (EDH) is the predominant mechanism by which these arteries vasodilate. Using isolated, pressurized resistance arteries, we demonstrate that VEGF-A acts via VEGF receptor-2 (R2) to inhibit both endothelial cell (EC) Ca²⁺ release and the associated EDH vasodilatation mediated by intermediate conductance Ca²⁺ -activated K⁺ (IK_Ca ) channels. Importantly, VEGF-A had no direct effect against IK_Ca channels. Instead, the inhibition was crucially reliant on the downstream activation of the mitogen-activated protein/extracellular signal-regulated kinase kinase 1/2 (MEK1/2). The distribution of EC inositol 1,4,5-trisphosphate (IP₃ ) receptor-1 (R1) was not affected by exposure to VEGF-A and we propose an inhibition of IP₃ R1 through the MEK pathway, probably via ERK1/2. Inhibition of EC Ca²⁺ via VEGFR2 has profound implications for EDH-mediated dilatation of resistance arteries and could provide a mechanism by which elevated VEGF-A contributes towards cardiovascular dysfunction.

Correlation between increasing tissue ischemia and circulating levels of angiogenic growth factors in peripheral artery disease

INTRODUCTION

The aim of the present study was to assess the circulating levels of vascular endothelial growth factor (VEGF) and other suggested therapeutic growth factors with the degree of ischemia in patients with different clinical manifestations of peripheral arterial disease (PAD) according to the Rutherford grades.

METHODS

The study cohort consists of 226 consecutive patients admitted to a Department of Vascular Surgery for elective invasive procedures. PAD patients were grouped according to the Rutherford grades after a clinical assessment. Ankle-brachial pressure indices (ABI) and absolute toe pressure (TP) values were measured. Serum levels of circulating VEGF, hepatocyte growth factor (HGF), basic fibroblast growth factor (bFGF), and platelet derived growth factor (PDGF) were measured from serum and analysed against Rutherford grades and peripheral hemodynamic measurements.

RESULTS

The levels of VEGF (P = 0.009) and HGF (P < 0.001) increased significantly as the ischaemic burden became more severe according to the Rutherford grades. PDGF behaved in opposite manner and declined along increasing Rutherford grades (P = 0.004). A significant, inverse correlations between Rutherford grades was detected as follows; VEGF (Pearson's correlation = 0.183, P = 0.004), HGF (Pearson's correlation = 0.253, P < 0.001), bFGF (Pearson's correlation = 0.169, P = 0.008) and PDGF (Pearson's correlation = 0.296, P < 0.001). In addition, VEGF had a clear direct negative correlation with ABI (Pearson's correlation -0.19, P = 0.009) and TP (Pearson's correlation -0.20, P = 0.005) measurements.

CONCLUSIONS

Our present observations show that the circulating levels of VEGF and other suggested therapeutic growth factors are significantly increased along with increasing ischemia. These findings present a new perspective to anticipated positive effects of gene therapies utilizing VEGF, HGF, and bFGF, because the levels of these growth factors are endogenously high in end-stage PAD.

Overweight and obesity versus concentrations of VEGF-A, sVEGFR-1, and sVEGFR-2 in plasma of patients with lower limb chronic ischemia

OBJECTIVE

Being overweight or obese comprises a significant risk factor for atherosclerosis. Fat tissue also generates factors stimulating angiogenesis, the process by which new blood vessels form. The purpose of this paper is to assess concentrations of the vascular endothelial growth factor A (VEGF-A) and its soluble type-1 and type-2 receptors (sVEGFR-1 and sVEGFR-2) in plasma of patients with peripheral arterial disease (PAD) depending on the level of nutrition according to body mass index (BMI).

METHODS

The study group included patients suffering from symptomatic PAD (n=46) in Fontaine classes IIa-IV without any history of neoplastic disease and who have a normal BMI (n=15), are overweight (n=21) or are obese (n=10). The control group (n=30) consisted of healthy non-smoking volunteers who were neither overweight nor obese. Venous blood plasma samples were collected from both groups at rest in the morning to determine plasma concentrations of VEGF-A, sVEGFR-1, and sVEGFR-2 using the enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

The group of patients with PAD co-existent with being overweight or obese tended to have higher mean concentration levels of VEGF-A and sVEGFR-2 when compared with patients suffering from PAD with normal BMI. A statistically significant positive correlation was obtained between BMI and average plasma concentrations of sVEGFR-2 (R=0.37, P=0.0103). However, no significant correlation was noticed between BMI and VEGF-A or sVEGFR-1 concentrations.

CONCLUSIONS

A positive correlation determined between the level of antiangiogenic factor and BMI value may be indicative of the linearly growing prevalence of some antiangiogenic factors in patients with metabolic disorders, which may be one of numerous factors contributing to incomplete efficiency of collateral circulation development in patients with PAD.

Limb ischemia and vessel regeneration: Is there a role for VEGF?

Vascular endothelial growth factor (VEGF), as an endothelial cell-specific mitogen, is crucial for new blood vessels formation. Atherosclerosis affecting the cardiovascular system causes ischemia and functio laesa in tissues supplied by the occluded vessels. When such a situation occurs in the lower extremities, it causes critical limb ischemia (CLI) often requiring leg amputation. Low oxygen tension leads to upregulation of hypoxia-regulated genes (i.e. VEGF), that should help to restore the impaired blood flow. In CLI these rescue mechanisms are, however, often inefficient. Moreover, there are many contradictory reports showing either induction, no changes or even down-regulation of VEGF in specimens taken from patients with CLI, as well as in samples collected from animals subjected to hindlimb ischemia. Additionally, taking into account numerous experimental and clinical data demonstrating rather insufficient therapeutic potential of VEGF, we called into question the role of this protein in limb ischemia and vessel regeneration. In this review we are also summarizing several aspects which can influence VEGF expression and its measurement in the ischemic tissues.

Compared to Intermittant Claudication Critical Limb Ischemia Is Associated with Elevated Levels of Cytokines

Critical limb ischemia (CLI) is the advanced stage of peripheral artery disease (PAD) and associated with an extremely poor clinical outcome. In order to understand the possible role of circulating cytokines and poor outcome associated with CLI we compared the circulating cytokine profile of patients with CLI against patients with intermittent claudication (IC). The levels of 48 circulating cytokines were examined in 226 consecutive patients with peripheral artery disease (PAD) admitted for elective, non-urgent, invasive treatment of IC or CLI. The PAD patient cohort was evenly distributed between subjects with IC (46.5%) and CLI (53.5%). As accustomed in PAD, CLI was associated with higher age, chronic kidney disease and diabetes when compared to IC (P < 0.01 for all). In multivariable linear regression modeling taking into account the baseline differences between IC and CLI groups CLI was independently associated with elevated levels of a large number of cytokines: IL-1β, IL-1ra, IL-2Rα, IL-4, IL-6, IL-10, IFN-γ, GM-CSF, G-CSF (P < 0.01 for all), and IL-2, IL-7, IL-12, IL-13, IL-17, bFGF, VEGF, SCGF-β (P < 0.05 for all). The current findings indicate that CLI is associated with a circulating cytokine profile, which resembles serious medical conditions such as severe pancreatitis, sepsis, or even cancer. Compared to IC, CLI is a systemic inflammatory condition, which may explain the extremely poor outcome associated with it.

Reductions in circulating levels of IL-16, IL-7 and VEGF-A in myalgic encephalomyelitis/chronic fatigue syndrome

Recently, differences in the levels of various chemokines and cytokines were reported in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) as compared with controls. Moreover, the analyte profile differed between chronic ME/CFS patients of long duration versus patients with disease of less than 3years. In the current study, we measured the plasma levels of 34 cytokines, chemokines and growth factors in 100 chronic ME/CFS patients of long duration and in 79 gender and age-matched controls. We observed highly significant reductions in the concentration of circulating interleukin (IL)-16, IL-7, and Vascular Endothelial Growth Factor A (VEGF-A) in ME/CFS patients. All three biomarkers were significantly correlated in a multivariate cluster analysis. In addition, we identified significant reductions in the concentrations of fractalkine (CX3CL1) and monokine-induced-by-IFN-γ (MIG; CXCL9) along with increases in the concentrations of eotaxin 2 (CCL24) in ME/CFS patients. Our data recapitulates previous data from another USA ME/CFS cohort in which circulating levels of IL-7 were reduced. Also, a reduced level of VEGF-A was reported previously in sera of patients with Gulf War Illness as well as in cerebral spinal fluid samples from a different cohort of USA ME/CFS patients. To our knowledge, we are the first to test for levels of IL-16 in ME/CFS patients. In combination with previous data, our work suggests that the clustered reduction of IL-7, IL-16 and VEGF-A may have physiological relevance to ME/CFS disease. This profile is ME/CFS-specific since measurement of the same analytes present in chronic infectious and autoimmune liver diseases, where persistent fatigue is also a major symptom, failed to demonstrate the same changes. Further studies of other ME/CFS and overlapping disease cohorts are warranted in future.

A review of the pathophysiology and potential biomarkers for peripheral artery disease

Peripheral artery disease (PAD) is due to the blockage of the arteries supplying blood to the lower limbs usually secondary to atherosclerosis. The most severe clinical manifestation of PAD is critical limb ischemia (CLI), which is associated with a risk of limb loss and mortality due to cardiovascular events. Currently CLI is mainly treated by surgical or endovascular revascularization, with few other treatments in routine clinical practice. There are a number of problems with current PAD management strategies, such as the difficulty in selecting the appropriate treatments for individual patients. Many patients undergo repeated attempts at revascularization surgery, but ultimately require an amputation. There is great interest in developing new methods to identify patients who are unlikely to benefit from revascularization and to improve management of patients unsuitable for surgery. Circulating biomarkers that predict the progression of PAD and the response to therapies could assist in the management of patients. This review provides an overview of the pathophysiology of PAD and examines the association between circulating biomarkers and PAD presence, severity and prognosis. While some currently identified circulating markers show promise, further larger studies focused on the clinical value of the biomarkers over existing risk predictors are needed.

Impact of VEGF polymorphisms on the severity of peripheral artery disease in diabetic patients

OBJECTIVE

To determine the potential genotype vascular endothelial growth factor (VEGF) gene differences in diabetic patients with peripheral arterial disease (PAD), which might be associated with different stages of the vascular disease.

METHODS

A study was conducted with type 2 diabetic patients with PAD [n = 70; 32 intermittent claudication and 38 critical limb ischaemia (CLI)]. Genotyping of the VEGF gene insertion/deletion - 2549, - 2578 C/A and +405 G/C polymorphisms was done in both groups and correlated them with the severity of PAD. We compared serum VEGF levels in both groups.

RESULTS

There was a higher frequency of +405 CC and - 2578 CC genotypes in claudication group [(31.3% vs. 5.4%, p = 0.01) and (37.5% vs. 15.8%, p = 0.05), respectively]. The presence of +405 GG and - 2578 AA genotypes was more common among CLI patients [(57.8% vs. 37.5%, p = 0.01) and (42.1% vs. 18.8%, p = 0.05), respectively]. There were higher serum VEGF levels in patients with CLI (p = 0.029).

CONCLUSIONS

We found preliminary evidence regarding the association between VEGF polymorphisms and different stages of PAD in diabetic patients.

Significance of vascular endothelial growth factor in growth and peritoneal dissemination of ovarian cancer

Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis which drives endothelial cell survival, proliferation, and migration while increasing vascular permeability. Playing an important role in the physiology of normal ovaries, VEGF has also been implicated in the pathogenesis of ovarian cancer. Essentially by promoting tumor angiogenesis and enhancing vascular permeability, VEGF contributes to the development of peritoneal carcinomatosis associated with malignant ascites formation, the characteristic feature of advanced ovarian cancer at diagnosis. In both experimental and clinical studies, VEGF levels have been inversely correlated with survival. Moreover, VEGF inhibition has been shown to inhibit tumor growth and ascites production and to suppress tumor invasion and metastasis. These findings have laid the basis for the clinical evaluation of agents targeting VEGF signaling pathway in patients with ovarian cancer. In this review, we will focus on VEGF involvement in the pathophysiology of ovarian cancer and its contribution to the disease progression and dissemination.

Enhanced vascular endothelial growth factor gene expression in ischaemic skin of critical limb ischaemia patients

Objectives. To perform a quantitative analysis of the vascular endothelial growth factor (VEGF) gene transcription in the skin of ischemic legs and provide information for VEGF in the pathogenesis in critical limb ischemia (CLI). Methods. Skin biopsies were obtained from 40 patients with CLI. Control samples came from 44 patients with chronic venous disease. VEGF gene expression was analysed using quantitative polymerase chain reaction. Results. Patients with CLI had higher skin VEGF expression than control group (RQ: 1.3 ± 0.1 versus 1, P = 0.04). Conclusions. We found an association between ischemic skin and an elevated VEGF expression in legs from patients with CLI. These data support that the mechanism for VEGF upregulation in hypoxia conditions is intact and acts appropriately in the ischaemic limbs from patients with CLI.

Assessment of levels of vascular endothelial growth factor in patients with ESRD and its possible role in cardiovascular morbidity and mortality

Patients with end-stage renal disease (ESRD) are known to have an elevation of a variety of abnormal thrombotic and inflammatory markers associated with high cardiovascular mortality. Vascular endothelial growth factor (VEGF) is also dysregulated in ESRD but not much is known about the serum levels of VEGF in patients with ESRD. Published reports suggest that elevated levels of VEGF may be protective to the kidney during periods of acute injury and may maintain local glomerular function. Impaired production of VEGF may lead to proteinuria, hypertension, and thrombotic microangiopathy. However, its role in chronic kidney disease or ESRD remains undefined. In our study, we analyzed blood samples of 52 patients with ESRD on stable hemodialysis regimen and measured predialysis serum levels of VEGF and compared these with blood samples obtained from 50 healthy volunteers in order to study differences between baseline levels of VEGF and also attempted to determine its role in ESRD-related cardiovascular mortality.

Vascular endothelial growth factor polymorphisms are involved in the late vascular complications in Type II diabetic patients

AIM

To determine the potential genotype differences in the vascular endothelial growth factor (VEGF) gene in diabetic patients, which might explain the difference in terms of the development of clinical vascular complications: great vessels atherosclerosis vs. retinopathy.

METHODS

Genotyping of the VEFG gene insertion/deletion -2549, the C-2578A and the G+405C polymorphisms was done in 40 diabetic patients (26 with peripheral artery disease (PAD) and 14 with diabetic retinopathy (DR)).

RESULTS

There was a significant increase in the frequency of the VEGF -2549 DD genotype in PAD patients compared with the DR group (34.6 vs. 0; p = 0.016), as well as in the distribution of the VEGF -2549 ID genotype in DR compared with PAD patients (85.7 vs. 38.4; p = 0.005). There was a significant increase in the frequency of the VEGF -2578 CC genotype in the PAD group compared with DR (34.6 vs. 0; p = 0.016), as well as in the VEGF -2578 CA genotype in DR patients compared with PAD (85.7 vs. 34.6; p = 0.002). The VEGF +405 genotype was not associated with diabetic vascular complications.

CONCLUSION

This study provides preliminary evidence that VEGF polymorphisms are associated with a differential presentation of diabetic vascular complications.