Serum VEGF-C levels as a candidate biomarker of hypervolemia in chronic kidney disease

Effect of Personalized Sodium Replacement on Fluid and Sodium Balance and Thermophysiological Strain During and After Ultraendurance Running in the Heat

PURPOSE

To investigate the effect of personalized sweat sodium replacement on drinking behavior, sodium and water balance, and thermophysiological responses during and after ultraendurance running in hot conditions.

METHODS

Nine participants (7 male, 2 female) completed two 5-hour treadmill runs (60% maximum oxygen uptake, 30°C ambient temperature), in a double-blind randomized crossover design, consuming sodium chloride (SODIUM) capsules to replace 100% of previously assessed losses or placebo (PLACEBO). Fluid was consumed ad libitum.

RESULTS

No effect of SODIUM was observed for ad libitum fluid intake or net fluid balance (P > .05). Plasma sodium concentration increased in both trials, but to a greater extent in SODIUM at 2.5 hours (mean [SD]: 4 [4] mmol·L-1 vs 1 [5] mmol·L-1; P < .05) and postexercise (4 [3] mmol·L-1 vs 1 [5] mmol·L-1; P < .05). Plasma volume change was not different between trials (P > .05) but was strongly correlated with sodium balance in SODIUM (r = .880, P < .01). No effect of sodium replacement was observed for heart rate, rectal temperature, thermal comfort, perceived exertion, or physiological strain index. During the 24 hours postexercise, ad libitum fluid intake was greater following SODIUM (2541 [711] mL vs 1998 [727] mL; P = .04), as was urinary sodium excretion (NaCl: 66 [35] mmol, Pl: 21 [12] mmol; P < .01).

CONCLUSIONS

Personalized sweat sodium replacement during ultraendurance running in hot conditions, with ad libitum fluid intake, exacerbated the rise in plasma sodium concentration compared to no sodium replacement but did not substantially influence overall body-water balance or thermophysiological strain. A large sodium deficit incurred during exercise leads to substantial renal sodium conservation postexercise.

Correlation of serum VEGF-C, ANGPTL4, and activin A levels with frailty

BACKGROUND

Secretory factors linked to lymphogenesis, such as vascular endothelial growth factor C (VEGF-C), angiopoietin like protein 4 (ANGPTL4), and activin A (ACV-A), have been recognized as potential markers of chronic inflammatory status and age-related diseases. Furthermore, these factors may also be linked to frailty. The primary objective of this study was to examine the serum VEGF-C, ANGPTL4, and ACV-A levels in young individuals, healthy older individuals, and older individuals with pre-frailty and frailty, and to determine their association with pro-inflammatory factor levels.

METHODS

We conducted an observational study, enrolling a total of 210 older individuals and 20 young healthy volunteers. Participants were divided into four groups based on the Freid frailty phenotype: healthy young group, older patients without frailty group, pre-frail older group, and frail older group. Plasma and peripheral blood mononuclear cells (PBMCs) were collected from all four groups. ELISA was used to measure the serum levels of VEGF-C, ANGPTL4, ACV-A, and pro-inflammatory cytokines, while RT-qPCR was used to measure the transcription level of VEGF-C, ANGPTL4 and ACV-A in PBMCs.

RESULTS

In comparison to healthy young individuals and older participants without frailty, older participants with frailty exhibited lower renal function, higher serum levels and transcription levels of VEGF-C, ANGPTL4, ACV-A, and elevated levels of pro-inflammatory cytokines (CRP, IL-1β, and TNF-α). Multiple linear regression analysis revealed that serum levels of VEGF-C, ANGPTL4, and ACV-A were positively correlated with the frailty index, independent of age, eGFR, and comorbidities. Furthermore, the receiver operating characteristic (ROC) curve analysis demonstrated that serum levels of VEGF-C, ANGPTL4, and ACV-A have great accuracy in predicting frailty.

CONCLUSION

Elevated serum levels of VEGF-C, ANGPTL4, and ACV-A are associated with frailty status.

Association of vascular endothelial growth factor (VEGF) protein levels and gene polymorphism with the risk of chronic kidney disease

Vascular endothelial growth factor (VEGF) is a heparin-specific growth factor specific for vascular endothelial cells and induces angiogenesis via binding to vascular endothelial growth factor receptor (VEGFR). Chronic kidney disease (CKD), accompanied by microvascular disease, is recognized as an irreversible reduction of renal function. The effects of VEGF on CKD risk were evaluated in this study. 121 CKD patients and 50 healthy volunteers were evaluated in the current study. Data mining using the China Biological Medicine (CBM) and NCBI/PubMed databases, was performed and applicable investigations were pursued. Pooled mean differences (MD) and pooled odds ratios (OR), with corresponding confidence intervals (CIs), were calculated by meta-analysis. The levels of Scr, BUN and VEGF in the CKD group were significantly higher, when compared with the control group (P < 0.01). For the meta-analysis, thirteen articles and our current study were evaluated. VEGF levels was found to be associated with CKD risk (P < 0.00001). In the sub-group meta-analysis, we found that the pooled MD of VEGF levels was related to the early CKD group, although the difference was not notable. However, the meta-analysis itself indicated that the pooled MD of VEGF levels were in accordance with severe CKD group (P < 0.00001). Furthermore, VEGF +936C/T T allele was not associated with CKD risk (P = 0.69). VEGF levels are apparently associated with CKD risk, especially in more severe CKD. Gene polymorphism analysis indicates that the VEGF +936C/T T allele is not associated with CKD risk.

Vascular endothelial growth factor-D plasma levels in fluid overload and cardiac function evaluation of elderly patients with cardiovascular disease

This study aimed to investigate the clinical significance of vascular endothelial growth factor (VEGF) subtypes and growth differentiation factor-15 (GDF-15) plasma levels in evaluating the fluid overload and cardiac function of elderly patients with cardiovascular disease. The plasma levels of VEGF-C, VEGF-D, and GDF-15 were measured using ELISA. Their correlations with N-terminal pro B-type natriuretic peptide (NT-Pro BNP) and echocardiography data were analyzed. 1. Higher plasma levels of VEGF-D and GDF-15 were observed in elderly patients with cardiovascular disease and heart failure(P < .01). VEGF-D plasma levels were higher in patients with chronic heart failure than those with acute myocardial infarction (P < .01). VEGF-D plasma levels were positively correlated with amino-terminal pro-B type natriuretic peptide (NT-pro BNP) (P < .001). VEGF-D plasma levels were positively correlated with echocardiographic parameters, including left atrial diameter, left ventricular end-diastolic diameter and left ventricular ejection fraction, in patients with cardiovascular disease (P < .01). 2. VEGF-C plasma levels were higher in acute myocardial infarction group (P < .05). The plasma levels of VEGF-C were not correlated with either VEGF-D or NT-pro BNP plasma levels. VEGF-C plasma levels had no correlation with echocardiographic parameters. 3. GDF-15 plasma levels were positively correlated with sera biomarkers of cardiac injury (creatine kinase isoenzyme MB and cardiac troponin I). GDF-15 plasma levels were positively correlated with urinary biomarkers of tubular injury (N-acetyl-β-galactosidase and α1-microglobulin). Both GDF-15 and NT-pro BNP plasma levels were correlated with age, estimated glomerular filtration rate (eGFR), and nutritional biomarkers (albumin and hemoglobin plasma levels). VEGF-D plasma levels is a potential biomarker of fluid overload and cardiac function in elderly patients with cardiovascular disease. Age, nutrition, and kidney injury are factors influencing both GDF-15 and NT-pro BNP plasma levels in estimating cardiac function and fluid overload.

The Growth Factors: Potential Biomarkers and Therapeutic Targets in Kidney Diseases

BACKGROUND

Kidney diseases are a prevalent health problem worldwide. Although substantial progress has been made in understanding the pathophysiology of kidney disease, currently there is no satisfactory clinical treatment available to prevent or treat kidney disease. Therefore, strategies to establish early diagnosis, identify the key molecules, and develop novel therapeutic interventions to slow the progression of kidney diseases and reduce their complications are encouraged.

SUMMARY

The growth factors play a crucial role in the development of kidney diseases. The altered levels of growth factors are usually detected in circulation and urine in the disease course. A growing body of studies has suggested that growth factors, receptors, and related regulators are promising biomarkers for the diagnosis and/or prognosis and potential therapeutic targets for the treatment of kidney diseases. In this review, we summarize recent advances in the potential applications of growth factors for diagnostic biomarkers and therapeutic targets in kidney diseases and highlight their performances in clinical trials.

KEY MESSAGES

Most diagnostic and therapeutic strategies targeting growth factors are still far from clinical implementation. The better understanding of growth factor-regulated pathophysiology and the progress of new intervention approaches are expected to facilitate the clinical translation of growth factor-based diagnosis and therapy of kidney diseases.

Modelling sodium requirements of athletes across a variety of exercise scenarios - identifying when to test and target, or season to taste

AbstractEvidence suggests the focus for sodium replacement during exercise should be maintenance of plasma sodium concentration ([Na⁺]_plasma) for any given total body water (TBW) volume. The sodium intake to achieve stable [Na⁺]_plasma given known fluid and electrolyte intakes and losses can be mathematically estimated. Therefore the aim of this investigation was to model sodium requirements of athletes during exercise, observing the influence of sweat rate, exercise duration, body mass, baseline [Na⁺]_plasma and sweat potassium [K⁺]_sweat, and relevance to competition (soccer, elite marathon, and 160 km ultramarathon running). Models were constructed across a range of sweat sodium concentrations ([Na⁺]_sweat) (20-80 mmol·L^-1), sweat rates (0.5-2.5 L·h^-1) and fluid replacement (10-90% of losses). In the competition-specific scenarios, fluid replacement was calculated to achieve 2% TBW losses. Sodium requirements were driven by fluid replacement (% of losses) and [Na⁺]_sweat, with minimal or no influence of other variables. Replacing sodium was unnecessary in all realistic scenarios modelled for a soccer match and elite marathon. In contrast, the 160 km ultramarathon required ≥47% sodium replacement when [Na⁺]_sweat was ≥40 mmol·L^-1 and >80% of fluid losses were replaced. In conclusion, sodium requirements to maintain stable [Na⁺]_plasma during exercise depend on both the proportion of fluid losses replaced, and [Na⁺]_sweat. Only when prolonged exercise is coupled with aggressive fluid replacement (>80%) and whole body [Na⁺]_sweat ≥40 mmol·L^-1 does sweat composition testing and significant, targeted sodium replacement appear necessary.

Serum VEGF-D level is correlated with renal dysfunction and proteinuria in patients with diabetic chronic kidney disease

Biomarkers associated with chronic kidney disease (CKD) may play a crucial role in the early diagnosis of diabetic kidney disease. However, there have been few reports published on serum vascular endothelial cell growth factor (VEGF)-D in patients with diabetic CKD. We divided patients with diabetic CKD into two groups: CKD 3-4 and CKD 5. In total, 42 patients with diabetic kidney disease and seven healthy controls without diabetes mellitus were enrolled in this study. An observational study was conducted to evaluate the serum VEGF-D levels and other clinical parameters in each group and to assess the relationship among these factors. The serum levels of VEGF-D were higher in the CKD 3-4 group and CKD 5 group than in the control group. However, there was no significant difference in serum levels of VEGF-D between CKD stage 3-4 group and CKD stage 5 group. Correlation analysis showed that serum VEGF-D was negatively correlated with estimated glomerular filtration rate but positively correlated with serum creatinine, urine albumin-to-creatinine ratio, and urine protein-to-creatinine ratio. Serum VEGF-D was a good biomarker in receiver operating characteristic analysis and independently associated with CKD stages in multiple linear regression analysis. Circulating VEGF-D was positively correlated with blood growth/differentiation factor-15, endostatin, and chemokine (C-X-C motif) ligand 16 levels. Serum VEGF-D levels were correlated with renal dysfunction, albuminuria, and proteinuria in patients with diabetic kidney disease. Elucidation of the role of VEGF-D as a biomarker requires further study.

Exertional heat stress and sodium balance: Leaders, followers, and adaptations

Exertional heat stress presents a different acute challenge to salt balance compared to at rest. Sodium (Na⁺) and chloride (Cl^-) losses during exercise are overwhelmingly driven by eccrine sweat glands (the "leader"), with minimal urinary excretion. Total salt losses are therefore largely influenced by thermoregulatory need, although adaptations from prior heat exposure or altered dietary intake influences sweat gland ion reabsorption, and therefore sweat Na⁺ ([Na⁺]_sweat) and Cl^- concentrations. The hypotheses that body Na⁺ and Cl^- conservation, or their release from osmotically inactive stores, can occur during the timeframe of a single bout of exertional heat stress, has not been studied to date. The consequences of unreplaced Na⁺ and Cl^- losses during exertional heat stress appear limited primarily to their interactions with water balance. However, the water volume ingested is substantially more influential than salt intake on total body water, plasma volume, osmolality, and thermoregulation during exercise. Acute salt and water loading 1-3 h prior to exercise can induce isosmotic hyperhydration in situations where this is deemed beneficial. During exercise, only scenarios of whole body [Na⁺]_sweat > 75th centile, combined with fluid replacement >80% of losses, are likely to require significant replacement to prevent hyponatremia. Post-exercise, natriuresis resumes as the main regulator of salt losses, with the kidneys (the "follower") working to restore salt balance incurred from any exercise-induced deficit. If such a deficit exceeds usual dietary intake, and rapid restoration of hydration status is desirable, a deliberate increase in salt intake may assist in volume restoration.

HIV-Associated Cancer Biomarkers: A Requirement for Early Diagnosis

Globally, HIV/AIDS and cancer are increasingly public health problems and continue to exist as comorbidities. The sub-Saharan African region has the largest number of HIV infections. Malignancies previously associated with HIV/AIDS, also known as the AIDS-defining cancers (ADCs) have been documented to decrease, while the non-AIDS defining cancer (NADCs) are on the rise. On the other hand, cancer is a highly heterogeneous disease and precision oncology as the most effective cancer therapy is gaining attraction. Among HIV-infected individuals, the increased risk for developing cancer is due to the immune system of the patient being suppressed, frequent coinfection with oncogenic viruses and an increase in risky behavior such as poor lifestyle. The core of personalised medicine for cancer depends on the discovery and the development of biomarkers. Biomarkers are specific and highly sensitive markers that reveal information that aid in leading to the diagnosis, prognosis and therapy of the disease. This review focuses mainly on the risk assessment, diagnostic, prognostic and therapeutic role of various cancer biomarkers in HIV-positive patients. A careful selection of sensitive and specific HIV-associated cancer biomarkers is required to identify patients at most risk of tumour development, thus improving the diagnosis and prognosis of the disease.

Vascular endothelial growth factor D is a biomarker of fluid overload in haemodialysis patients

BACKGROUND

Improved understanding and assessment of the complex physiology of volume regulation in haemodialysis (HD) patients are required to improve patient care and reduce mortality associated with fluid overload (FO).

METHODS

We searched for FO-related biomarkers among 184 peptides associated with cardiovascular disease in a cohort of 30 HD patients. First, we assessed the direct impact of HD on the peptides of interest by comparing plasma concentrations before and after treatment. Then, we compared cardiovascular peptide profiles between patients with and without FO as defined by bioimpedance analysis (BIA). The plasma concentration of selected candidate biomarkers for FO was determined by enzyme-linked immunosorbent assay (ELISA) and correlated with previously described FO-related clinical and laboratory parameters. For validation, results were confirmed in an independent cohort of 144 HD patients.

RESULTS

We found seven peptides positively [NT-proBNP, B-type natriuretic peptide (BNP), vascular endothelial growth factor D (VEGFD), tumour necrosis factor-related apoptosis-inducing ligand receptor 2, growth differentiation factor 15, tumour necrosis factor ligand superfamily member 13B, chitinase-3-like protein 1] and five negatively (leptin, renin, epidermal growth factor receptor, interleukin-1 receptor antagonist, myeloblastin) correlated to FO. In addition to natriuretic peptides, VEGFD emerged as third peptide highly correlated with BIA (ρ = 0.619, P < 0.0001). In line with this, VEGFD concentration verified by ELISA correlated with BIA, BNP and soluble CD146 but not with vascular endothelial growth factor C (VEGFC). Notably, levels of VEGFD were unrelated to cardiac systolic function (P = 0.63), contrary to BNP (P = 0.0003). Finally, we observed that 1-year all-cause mortality was higher in patients with high BNP (P = 0.0002), FO (defined by BIA, P = 0.04) and high VEGFD (P = 0.02), but not with high VEGFC (P = 0.48).

CONCLUSION

VEGFD is a novel FO-related biomarker with unique diagnostic and prognostic properties.

On-line hemodiafiltration modulates atherosclerosis signaling in peripheral lymphomonocytes of hemodialysis patients

Background

Hemodialysis patients present a dramatic increase in cardiovascular morbidity/mortality. Circulating immune cells, activated by both uremic milieu and dialysis, play a key role in the pathogenesis of dialysis-related vascular disease. The aim of our study was to identify, through a high-throughput approach, differences in gene expression profiles in the peripheral blood mononuclear cells (PBMCs) of patients treated with on-line hemodiafiltration and bicarbonate hemodialysis.

Methods

The transcriptomic profile was investigated in PBMCs isolated from eight patients on on-line hemodiafiltration and eight patients on bicarbonate hemodialysis by microarray analysis. The results were evaluated by statistical and functional pathway analysis and validated by real time PCR (qPCR) in an independent cohort of patients (on-line hemodiafiltration N = 20, bicarbonate hemodialysis n = 20).

Results

Eight hundred and forty-seven genes were differentially expressed in patients treated with  on-line hemodiafiltration and bicarbonate hemodialysis. Thirty-seven functional gene networks were identified and atherosclerosis signaling was the top canonical pathway regulated by on-line hemodiafiltration. Among the genes of this pathway, on-line hemodiafiltration was associated with a reduced expression of Platelet-derived growth factor A chain (PDGF A), Clusterin, Monoamine Oxidase A, Interleukin-6 (IL-6) and Vascular Endothelial Growth Factor C (VEGF-)C and with an increase of Apolipoprotein E. qPCR confirmed the microarray results. Platelet derived growth factor AA (PDGF-AA), IL-6 and VEGF-C serum levels were significantly lower in the on-line hemodiafiltration group. Finally, 10 patients previously on bicarbonate hemodialysis  were switched to on-line hemodiafiltration and PBMCs were harvested after 6 months. The qPCR results from this perspective group confirmed the modulation of atherosclerotic genes observed in the cross-sectional analysis.

Conclusions

Our data suggest that type of dialysis (on-line hemodiafiltration versus bicarbonate hemodialysis) may modulate the expression of several genes involved in the pathogenesis of atherosclerotic disease.

Comparison of lung ultrasound and other volumetric methods in peritoneal dialysis patients

Although many alternative methods are present, maintaining ideal volume status in peritoneal dialysis (PD) patients still rely on clinical evaluation due to lack of an evidence-based method. Lung ultrasound (LUS) is a new method for evaluation of hidden congestion in this group.LUS findings and its relationship with other volumetric methods are investigated in this observational cross-sectional study.In this observational cross sectional study, LUS was performed to all PD patients and compared with symptoms of hypervolemia, physical examination, vascular endothelial growth factor-C (VEGF-C), and N-terminal pro-brain natriuretic peptide levels, chest radiography, echocardiography, bioelectrical impedance analysis.Data of 21 PD patients were evaluated. There was correlation between number of B lines and VEGF-C levels (r = 0.447, P = .042), daily urine output (r = 0.582, P = .007) and left ventricle mass index (r = -0.456, P = .038). Correlations with all other parameters were not significant. Daily urine output and VEGF-C levels were significantly different when B lines were grouped into 2 according to the median level (P < .05 for all).This is the widest spectrum study looking for LUS findings and other volumetric parameters in a small PD cohort. LUS might be useful to evaluate hidden hypervolemia. Its correlation with VEGF-C level is a novel finding.

Quality assessment of unsaturated iron-binding protein capacity in Iraqi patients undergoing hemodialysis

Hemodialysis is autoimmune disease result from inflammation, oxidative stress, and fibrosis. It is characterized by renal glomeruli damage, podocyte injury, tubule interstitial, and proteinuria. Electrolyte balance is the main function of the renal and any form of electrolyte disorders may lead to excess blood volume, hypertension, and difficulty in maintaining natural blood sodium. Renal erythropoietin has an important role in the balance of vascular active substances, such as prostaglandins and thromboxanes; therefore, patients undergoing hemodialysis observe decreased production of erythropoietin with iron loss through hemodialysis machine as well as weakened iron absorption and mobilization from the intestine to the bloodstream. Ferritin, total iron-binding capacity (TIBC), unsaturated iron-binding protein capacity (UIBC), iron free, and transferrin are used to confirm iron status. According the clinical characterization of the results, no normality was observed in patients undergoing hemodialysis. There was hypertension, anemia, lean symptoms and equal distribution of age parallel with developed disease, there was significant increased in renal function except albumin, it was decreased in the patients compared with control groups. In addition, there was a decreased level of iron status in all parameters such as packed cell volume (%), TIBC, UIBC, iron free, and transferrin except ferritin; there was an increased level of iron status in all parameters in patients compared with control groups.

Intradialytic hypotension: beyond hemodynamics

Intradialytic hypotension is a major complication during hemodialysis session, associated with increased risk of cardiovascular events and mortality. Its pathophysiology is believed to be multifactorial and remains not well elucidated. The aim of this study is to put forward new mechanisms behind the development of intradialytic hypotension. The study included sixty-five subjects on chronic hemodialysis, divided into two groups: intradialytic hypotensive (n=12) and normotensive (n=53), according to the variation of systolic blood pressure between post-dialysis and pre-dialysis measurements. Renin and angiotensin converting enzyme I plasma concentrations increased in both groups but more likely in normotensive group. Aldosterone plasma concentration is increased in the normotensive group while it decreased in the intradialytic hypotension group. Plasma endothelin concentrations showed higher values in intradialytic hypotension group. Post-dialysis asymmetric dimethylarginine and angiotensin converting enzyme 2 plasma concentrations were significantly higher in intradialytic hypotension group as compared to normotensive one. Collectrin plasma concentrations were significantly lower in intradialytic hypotension group. Finally, post-dialysis vascular endothelial growth factor C plasma concentration significantly increased in intradialytic hypotension group. In conclusion, endothelial dysfunction characterized by a lower level of vasoactive molecule seems to play a critical role in intradialytic hypotension development.

Risks of female genital tract related cancers (gynecological cancers) or breast cancer in women with and without chronic kidney disease: A population-based cohort study in Taiwan

This article aims to test the hypothesis that the risk of female genital tract related cancer (gynecological cancer: GC) or breast cancer (BC) of women with chronic kidney disease (CKD) might be different from that of those women without CKD.A nationwide 17-year historic cohort study using the National Health Insurance Research Database (NHIRD) of Taiwan and the Registry for Catastrophic Illness Patients was conducted. A total of 3045 women with a diagnosis of CKD from 1996 to 2013 and 3045 multivariable-matched controls (1:1) were selected. We used Cox regression, and computed hazard ratios (HRs) with 95% confidence intervals (95% CIs) to determine the risk of GC or BC in women.The GC incidence rates (IRs, per 10,000 person-years) of the CKD and non-CKD women were 11.02 and 19.09, respectively, contributing to a significantly decreased risk of GCs (crude HR 0.57, 95% CI 0.39-0.81; adjusted HR 0.44, 95% CI 0.30-0.65) in the CKD women. The GC IR was relatively constant in the CKD women among the different age categories (IR ranged from 8.10 to 12.29). On contrast, the non-CKD women had a progressive and continuous increase of GC IR in the advanced age, which was more apparent at age ≥50 years (IR 17.16 for 50-59; IR 23.05 for 60-69; and IR 31.62 for ≥70, respectively), contributing to the lower risk of GC in the CKD women than that in the non-CKD women. There was no difference of BC incidence between women with and without CKD.The findings of the lower risk of GCs in the CKD women in Taiwan are worthy of further evaluation.