Are Platelet-Related Parameters Prognostic Predictors of Renal and Cardiovascular Outcomes in IgA Nephropathy?

Background: IgA nephropathy (IgAN) is associated with chronic inflammation. Platelet-related parameters, such as the platelet (PLT) count, platelet-to-albumin ratio (PAR), and platelet-to-lymphocyte ratio (PLR), were examined as potential prognostic indicators for renal and cardiovascular (CV) outcomes in IgAN. We were interested in whether platelet-related parameters are risk factors for ESKD and CV events in IgAN patients. Methods: In a monocentric retrospective study, 124 IgAN patients were divided into two groups based on the cut-off value of the PAR. All-cause mortality, major CV events, and end-stage renal disease were the primary combined endpoints. Secondary endpoints, such as CV or renal endpoints, were also analyzed separately. Results: The patients' mean age was 43.7 ± 13.5 years, and the follow-up time was 124 ± 67 months. The K-M curve showed that the PLR, PAR, and PLT were strongly associated with primary combined (p = 0.002, p = 0.004, p = 0.001) and renal outcomes (p < 0.001, p < 0.001, p < 0.001), but not with CV outcomes in IgAN. However, when combined with left ventricular hypertrophy (LVH) or metabolic syndrome (MetS), the PAR was found to be a significant predictor of both primary (p < 0.001, p < 0.001) and secondary outcomes (p = 0.001 and p = 0.038; p = 0.001 and p = 0.015). Additionally, the PLR correlated with albuminuria (r = -0.165, p = 0.033) and LVH (r = -0.178, p = 0.025), while PLT correlated with eGFR (r = 0.158, p = 0.040). Conclusions. Elevated PARs and PLRs may predict progression to end-stage kidney disease, but in combination with LVH and MetS, they were related to CV events in IgAN. The determination of PARs and PLRs can be useful and cost-effective parameters for assessing both cardiovascular and renal risks in IgAN.

Renal and cardiovascular prognostic significance of echocardiographic early diastolic mitral annular velocity in IgA nephropathy

In chronic kidney disease (CKD), as in IgA nephropathy (IgAN), cardiovascular (CV) mortality and morbidity are many times higher than in the general population, and diastolic dysfunction (LVDD) has prognostic significance as well. Tissue Doppler Echocardiography (TDI) is another method for measuring myocardial contractility and determining diastolic dysfunction. 79 IgAN patients (age 46 ± 11 years) with CKD stages 1-3 were investigated and followed for 70 ± 28.7 months. Doppler echocardiography was used to measure the E (early) and A (late) waves, as well as the E wave deceleration time (EDT) during mitral inflow. TDI was used to measure early (Ea) and late (Aa) diastolic velocities (lateral and septal basal wall fragment average). From these, we calculated the E/Ea and Ea/Aa ratios. The primary combined endpoints were total mortality, major CV events, and end-stage renal disease, and the secondary endpoints were cardiovascular or renal (eGFR decreased below 15 ml/min/1.73 m2 or renal replacement therapy was started). Patients with decreased Ea (< 13 cm/s) had significantly more endpoints (20/42 vs. 3/37; p = 0.001) than patients with higher Ea (≥ 13 cm/s). The secondary renal endpoints were also significantly higher (p = 0.004). In a multivariate model, the eGFR showed independent correlation with the E/A ratio (r = 0.466; p < 0.01), EDT (r = - 0.270; p < 0.01), Ea/Aa ratio (r = 0.455; p < 0.01), and decreased Ea (r = 0.544; p < 0.01). Independent factors influencing Ea were only EDT by uni- and multivariate regression but age and albuminuria by logistic regression. Decreased Ea measured by TDI seems to be an eligible factor to predict the prognosis of IgA nephropathy. The decreased Ea may be a helpful parameter to identify high-risk CKD patients.

Relationship between arterial stiffness, left ventricular diastolic function, and renal function in chronic kidney disease

AIM

In chronic kidney disease, IgA nephropathy, and left ventricular diastolic dysfunction have prognostic significance as well. However, the relationship between diastolic dysfunction, arterial stiffness, and renal function has not been fully elucidated.

METHODS

79 IgA nephropathy patients (aged 46 ± 11 years) and 50 controls were investigated. Tissue Doppler imaging was used to measure early (Ea) and late (Aa) diastolic velocities. Arterial stiffness was measured by a photoplethysmographic (stiffness index (SI)) and an oscillometric method (aortic pulse wave velocity (PWVao)).

RESULTS

We compared the IgAN patients to a similar cardiovascular risk group with a preserved eGFR. A strong correlation was found between Ea/Aa and SI (p < 0.001), also with PWVao (p < 0.001), just in IgAN, and with eGFR (p < 0.001) in both groups. IgAN patients were divided into groups CKD1-2 vs. CKD3-5. In the CKD 3-5 group, the incidence of diastolic dysfunction increased significantly: 39% vs. 72% (p = 0.003). Left ventricle rigidity (LVR) was calculated, which showed a close correlation with SI (p = 0.009) and eGFR (p = 0.038). By linear regression analysis, the independent predictors of SI were age, E/A, and E/Ea; SI was the predictor of LVR; and E/A and hypertension were the predictors of eGFR.

CONCLUSION

In chronic kidney disease, increased cardiac rigidity and vascular stiffness coexist with decreased renal function, which is directly connected to diastolic dysfunction and vascular stiffness. On the basis of comparing the CKD group to the control group, vascular alterations in very early CKD can be identified.

The Role of Two Heart Biomarkers in IgA Nephropathy

Cardiovascular mortality is a leading cause of death in chronic kidney disease (CKD), as is IgA nephropathy (IgAN). The purpose of this study is to find different biomarkers to estimate the outcome of the disease, which is significantly influenced by the changes in vessels (characterized by arterial stiffness) and the heart. In our cross-sectional study, 90 patients with IgAN were examined. The N-terminal prohormone of brain natriuretic peptide (NT-proBNP) was measured as a heart failure biomarker by an automated immonoassay method, while the carboxy-terminal telopeptide of collagen type I (CITP) as a fibrosis marker was determined using ELISA kits. Arterial stiffness was determined by measuring carotid-femoral pulse wave velocity (cfPWV). Renal function and routine echocardiography examinations were performed as well. Based on eGFR, patients were separated into two categories, CKD 1-2 and CKD 3-5. There were significantly higher NT-proBNP (p = 0.035), cfPWV (p = 0.004), and central aortic systolic pressure (p = 0.037), but not CITP, in the CKD 3-5 group. Both biomarker positivities were significantly higher in the CKD 3-5 group (p = 0.035) compared to the CKD 1-2 group. The central aortic systolic pressure was significantly higher in the diastolic dysfunction group (p = 0.034), while the systolic blood pressure was not. eGFR and hemoglobin levels showed a strong negative correlation, while left ventricular mass index (LVMI), aortic pulse pressure, central aortic systolic pressure, and cfPWV showed a positive correlation with NT-proBNP. cfPWV, aortic pulse pressure, and LVMI showed a strong positive correlation with CITP. Only eGFR was an independent predictor of NT-proBNP by linear regression analysis. NT-proBNP and CITP biomarkers may help to identify IgAN patients at high risk for subclinical heart failure and further atherosclerotic disease.

Left ventricular myocardial mass index associated with cardiovascular and renal prognosis in IgA nephropathy

Introduction

In chronic kidney disease (CKD), like in IgA nephropathy (IgAN), cardiovascular (CV) mortality and morbidity are many times higher than in the general population, and left ventricular hypertrophy (LVH) is an independent risk factor for CV disease. This follow-up study investigated the association between left ventricular mass index (LVMI) and renal or cardiovascular outcomes.

Methods

We examined 118 IgAN patients prospectively. LVMI and LV geometry was investigated using echocardiography. The primary combined endpoints were total mortality, major CV events, and end-stage renal disease. Secondary endpoints, i.e.—cardiovascular or renal endpoints,—were also examined separately.

Results

Sixty seven percent were males, mean age 53.5 ± 13.5. Mean follow-up time: 184 months. LVMI inversely correlated with eGFR (corr. coefficient: -0.365; p < 0.01). We divided the patients into two groups based on the LVMI cut-off suggested by the literature. The presence of LVH caused a worse prognosis in primary (p < 0.001), renal endpoints (p = 0.01), and also in CV endpoints (p = 0.001). The higher LVMI in men significantly worsened the prognosis in all endpoints. Concentric hypertrophy meant a worse prognosis. Independent predictors of LVMI were gender and eGFR in uni- and multivariate regression and hemoglobin levels only in logistic regression. Independent predictors of the primary endpoint were LVMI, eGFR, gender, obesity, HT, DM, and metabolic syndrome in Cox regression analysis.

Conclusion

Increased LVMI may predict the progression to end-stage renal disease and CV events in IgAN. Determining LVMI may be a useful parameter not only in CV risk but also in the stratification of renal risk in CKD.

The prognostic role of heart rate recovery after exercise and metabolic syndrome in IgA nephropathy

Background

Cardiovascular (CV) morbidity and mortality are higher in chronic kidney disease (CKD) than in the general population. Reduced heart rate recovery (HRR) is an independent risk factor for CV disease. The aim of the study was to determine the prognostic role of HRR in a homogenous group of CKD patients.

Methods

One hundred and twenty-five IgA nephropathy patients (82 male, 43 female, age 54.7 ± 13 years) with CKD stage 1–4 were investigated and followed for average 70 months. We performed a graded exercise treadmill stress test. HRR was derived from the difference of the peak heart rate and the heart rate at 1 min after exercise. Patients were divided into two groups by the mean HRR value (22.9 beats/min). The composite (CV and renal) endpoints included all-cause mortality and any CV event such as stroke, myocardial infarction, revascularisation (CV) and end-stage renal disease, renal replacement therapy (renal).

Results

Patients with reduced HRR (< 23 bpm) had significantly more end point events (22/62 patients vs. 9/53 patients, p = 0.013) compared to the higher HRR (≥23 bpm). Of the secondary the endpoints (CV or renal separately) rate of the renal endpoint was significantly higher in the lower HRR group (p = 0.029), while there was no significant difference in the CV endpoint between the two HRR groups (p = 0.285). Independent predictors of survival were eGFR and diabetes mellitus by using Cox regression analysis. Kaplan-Meier curves showed significant differences in metabolic syndrome and non-metabolic syndrome when examined at the combined endpoints (cardiovascular and renal) or at each endpoint separately. The primary endpoint rate was increased significantly with the increased number of metabolic syndrome component (Met.sy. comp. 0 vs. Met. sy. comp. 2+, primary endpoints, p = 0.012).

Conclusion

Our results showed that reduced HRR measured by treadmill exercise test has a predictive value for the prognosis of IgA nephropathy. The presence of metabolic syndrome may worsen the prognosis of IgA nephropathy.

Cardiometabolic Effects of Irisin in Patients with End-Stage Renal Disease on Regular Hemo- or Peritoneal Dialysis

INTRODUCTION

Data on the role of irisin in vascular calcification in patients with end-stage renal diseases on regular dialysis are inconsistent, and the underlying mechanisms are not clearly defined. The present study was designed to explore the association of serum irisin with vascular stiffness and with the impact of well-established risk factors.

METHODS

The clinical study enrolled 52 hemodialysis (HD) and 15 continuous ambulatory peritoneal dialysis (PD) patients with an age of >18 years receiving dialysis therapy for >3 months. Patients who had major pathologies affecting carbohydrate, lipid, and bone metabolism and those who had acute cardiovascular events were excluded. Thirty-seven healthy subjects matched for age and sex served as controls. Routine biochemical parameters were measured in fasting serum samples by standard methods. Serum irisin was determined using the commercial ELISA kit (BioVendor Laboratory Medicine Inc., Brno, Czech Republic). Arterial stiffness parameters - carotid-femoral pulse wave velocity (cf PWV) and augmentation index (Aix) - were measured using applanation tonometry (SphygmoCor System; AtCor Medical, Sydney, Australia). Body composition was assessed by segmental bioelectric impedance (InBody 2.0; Biospace Co. Ltd., Seoul, Korea).

RESULTS

It was demonstrated that serum irisin levels were markedly depressed (p < 0.05), while the cf PWV significantly increased (p < 0.05) in HD/PD patients as compared to controls. Serum irisin proved to be independent of serum insulin, glucose, and HOMA-IR. However, it was inversely related to HbA1c (β = -0.544, p = 0.035), iPTH (β = -0.260, p = 0.035), and alkaline phosphatase (r = -0.325, p = 0.007). Furthermore, significant negative relationships were found of irisin to serum triglyceride and indices of body fat mass. Retrospective analysis at a follow-up period of 40 months revealed a direct relationship of irisin to all-cause mortality (p = 0.039).

CONCLUSIONS

Our study demonstrated that serum irisin levels are reduced in uremic patients on regular HD/PD but failed to establish significant associations of irisin deficiency with vascular stiffness. However, the significant negative relationship of irisin to HbA1c, iPTH, and alkaline phosphatase suggests that it improves insulin sensitivity, inhibits bone resorption, mitigates bone-vascular interaction, and protects vascular function.

Arterial stiffness may predict renal and cardiovascular prognosis in autosomal-dominant polycystic kidney disease

Background and aims

Autosomal-dominant polycystic kidney disease (ADPKD) is one of the most common causes of end-stage renal disease (ESRD). The most important cause of death among ADPKD patients is cardiovascular (CV). The aim of this study was to examine the prognostic significance of arterial stiffness on CV and renal outcomes in ADPKD.

Methods

A total of 55 patients with ADPKD were examined. Pulse wave velocity was determined and stiffness index (SIDVP) was calculated. Combined primary endpoints (CV and renal) were major CV events (myocardial infarction, stroke, and CV intervention) as CV endpoints, and attaining of ESRD or start of renal replacement therapy as renal endpoints. Secondary endpoints were CV or renal endpoints separately.

Results

The mean age of those 55 ADPKD patients was 45 ± 12 years, 21 patients were male. The average value of the SIDVP was 11.11 ± 2.22 m/s. The patients were divided into two groups by the cutoff value of 11 m/s of SIDVP and then outcomes were analyzed. In the higher arterial stiffness group (SIDVP > 11 m/s), occurrence of combined primary endpoint (CV and renal) was significantly higher than in the group with more elastic arteries (p = 0.033). A statistically significant difference was found in the renal endpoints (p = 0.018), but not in the CV endpoints (p = 0.952) between the two groups.

Conclusions

Increased arterial stiffness predicts the onset of ESRD in ADPDK. Assessment of SIDVP appears to be a useful method for estimating the renal and CV prognosis in ADPKD.

The Impact of Osteocalcin, Osteoprotegerin and Osteopontin on Arterial Stiffness in Chronic Renal Failure Patients on Hemodialysis

BACKGROUND/AIMS

This cross-sectional study was designed to assess the relationship between vascular stiffness (VS) and bone-related proteins involved in the development of arteriosclerosis in patients on regular hemodialysis (HD).

METHODS

68 consecutive patients in stable clinical condition who received regular HD in the FMC Dialysis Center, Pécs were included. VS parameters (carotid-femoral pulse wave velocity - PWV, aortic augmentation index - AIx) were determined by applanation tonometry (SphygmoCor, AtCor Medical, Sidney) and the routine latoratory test were completed with measurements of osteocalcin (OC), osteopontin (OP) and osteoprotegerin (OPG) by using commercially available ELISA kits. 35 heathcare workers served as controls.

RESULTS

In patients on regular HD PWV markedly increased and there was several-fold elevation in the interrelated bone-specific proteins (OC, OP, OPG). PWV was found to be independently associated only with OC (β:-0.25, p<0.029) and age (r=0.411,p<0.000), but risk factors for arterial calcification had significant impact on OC (systolic blood pressure, hsCRP, BMI), OPG (age, BMI) and OP (LDL-cholesterol).

CONCLUSION

Except for OC, our results failed to document direct association of vascular lesion with OP and OPG, therefore their high circulating levels may be an epiphenomenon or they may have counter-regulatory role to attenuate the uremic calcification process.

[Considerations on the treatment of IgA nephropathy on the basis of the results of the latest studies (STOP-IgAN, TESTING, NEFIGAN)]

IgA nephropathy is an immune-mediated chronic glomerulonephritis with a great variability in clinical presentation and outcome. The disease can progress to end-stage renal failure in 25% of patients. For this reason we should identify patients with potential to progress. Most important risk factors for progression are persistent proteinuria, hypertension, decreased renal function and some histological lesions. The actually suggested treatment is summarized in KDIGO Clinical Practice Guideline from 2012. They suggest to give firstly non-specific supportive treatment (especially renin-angiotensin system blocking agents). Recommendation about steroid/immunosuppression treatment is based on low level of evidence. Recently three studies were organised concerning benefits and risk of steroid/immunosuppressive treatment added together with specific supportive treatment. In the STOP-IgAN study, systemic steroid/immunosuppressive treatment significantly decreased proteinuria but did not stop progression. In the TESTING study, systemic steroid treatment significantly decreased proteinuria and progression. However, the study was recently discontinued due to several severe side effects of steroid treatment. Involvement of intestinal mucosal immunity in the pathogenesis of IgA nephropathy suggested the NEFIGAN study with budesonide treatment. Budesonide releases corticosteroid in distal small intestine and colon. Proteinuria was significantly decreased and renal function remained stabile. High number of withdrawals owing to adverse effects is a major concern implying a substantial systemic effect of budesonide. We need further information on the characteristics of patients who most likely benefit from steroid/immunosuppressive treatment given after or together with specific supportive treatment. Orv Hetil. 2017; 158(49): 1946-1952.

Metabolic syndrome and other cardiovascular risk factors associated with the progression of IgA nephropathy

Background

The metabolic syndrome is associated with modest but independent and additive risk of new onset chronic kidney disease (CKD) in several studies. The purpose of our study was to determine whether metabolic syndrome and other cardiovascular risk factors (hyperuricaemia and smoking) are associated with the progression of IgA nephropathy (IgAN).

Methods

Two hundred and twenty three IgAN patients (107 with and 116 without metabolic syndrome) were examined. The primary renal end point was doubling of serum creatinine; secondary end points were reaching eGFR of ≤ 60 ml/min/1,73m² or eGFR of ≤30 ml/min/1.73 m², and end-stage renal disease, ESRD (the composite of serum creatinine ≥500 μmol/l, initiation of dialysis treatment or transplantation). The association of metabolic syndrome with renal end points was examined using the Kaplan-Meier method and Cox models.

Results

Metabolic syndrome established at the diagnosis or during follow-up of IgAN patients was significantly associated with the primary renal end point (unadjusted hazard ratio of doubling of serum creatinine, 95% confidence interval: 1.96 (1.17–1.33, p = 0.011). The association remained significant after adjustment for confounders: 1.70 (1.02–3.83, p = 0.040). Results were similar for secondary end points except ESRD which was not associated with the presence of metabolic syndrome. Hyperuricaemia and smoking were independent risk factors of progression. Survival curves stratified on metabolic syndrome status showed significant differences for the end points (p = 0.017–0.001) except for ESRD.

Conclusions

Early diagnosis and treatment of metabolic syndrome, hyperuricaemia and smoking may be an additional cost-effective strategy for preventing the progression of IgAN.

[Therapy in IgA nephropathy--when and how to do it]

IgA nephropathy is the most common primary glomerulonephritis worldwide. The clinical spectrum covers a wide range of features from minor urinary abnormalities (asymptomatic hematuria and mild proteinuria with normal renal function) to acute and chronic renal insufficiency. Ideally, the goal of treatment would be to correct any defects in IgA1 glycosylation and to modify mesangial deposition or removal of IgA1 deposits. There are only a few randomized controlled trials in IgA nephropathy; for this reason most treatment options are largely based on expert opinion. Authors discuss therapeutic options of different clinical pictures and the optimized renoprotective treatment of all IgA nephropathy patients.

Cardiorenal syndromes

Cardiac and kidney diseases are very common, and increasingly coexist. Classification for cardiorenal syndrome and for its specific subtypes has been developed and published recently by a consensus group of the Acute Dialysis Quality Initiative. Cardiorenal syndromes have been classified according to whether the impairment of each organ is primary, secondary or whether heart and kidney dysfunction occurs simultaneously as a systemic disease. The different syndromes were classified into five subtypes. Type-1: acute cardiorenal syndrome: an abrupt worsening of cardiac function leading to acute kidney injury and/or dysfunction. Type-2: chronic cardiorenal syndrome: chronic abnormalities in cardiac function causing kidney injury and/or dysfunction. Type-3: acute renocardiac syndrome: abrupt worsening of kidney function leading to heart injury and/or dysfunction. Type-4: chronic renocardiac syndrome: chronic kidney diseases leading to heart injury, disease and/or dysfunction. Type-5: secondary cardiorenal syndrome: acute or chronic systemic diseases leading to simultaneous injury and/or dysfunction of heart and kidney. The identification of patients and the pathophysiological mechanisms underlying each syndrome subtype will help cardiologists, nephrologists and physicians working on intensive care units to characterize groups of their patients with cardiac and renal impairment and to provide a more accurate treatment for them. Orv. Hetil., 2011, 152, 1520–1527.