Cystatin C and Cardiac Measures in Children and Adolescents With CKD

Associations Between CYP3A5 (c.6986A>G) Gene Polymorphism and Kidney Impairment in Hypertensive Adults Without Cystatin C Elevation

OBJECTIVE

This study aimed to explore the potential role of CYP3A5 (c. 6986A>G) gene polymorphism in predicting kidney function impairment in patients with hypertension who did not have elevated serum cystatin C.

METHODS

We recruited a group of patients with hypertension who did not have elevated cystatin C and analyzed the CYP3A5 (c. 6986A>G) gene polymorphism. Chi-square tests were used to compare the clinical characteristics and genotypic distribution between the two groups. Logistic regression analysis was used to explore the association between CYP3A5 (c.6986A>G) gene polymorphism and renal function impairment in hypertension with non-elevated cystatin.

RESULTS

In patients with hypertension who participated in the study, there was a significant association between CYP3A5 (c. 6986A>G) gene polymorphism and kidney function impairment (p < 0.05). Patients with the CYP3A5 (c. 6986A>G) mutation display a greater risk of kidney function impairment.

CONCLUSION

CYP3A5 (c. 6986A>G) gene AA homozygote polymorphism significantly increases risk of kidney function impairment in patients with hypertension with normal cystatin C. However, further studies are needed to validate this association and to further understand the mechanism of CYP3A5 (c. 6986A>G) gene polymorphism in kidney function impairment in patients with hypertension.

Changes in the cardiovascular risk profile in children approaching kidney replacement therapy

Background

Despite significant cardiovascular (CV) morbidity in children on dialysis and after kidney transplantation, data on the evolution of CV damage in children with chronic kidney disease (CKD) approaching kidney replacement therapy (KRT) is unknown.

Methods

The burden, progression, and predictors of CV damage before KRT onset were explored in two prospective multicenter cohorts from Europe and Canada: Cardiovascular Comorbidity in Children with CKD (4C) and Haemodiafiltration, Heart and Height (3H) studies, conducted from 2009-19 and 2013-16, respectively. CV damage and risk factors were evaluated (i) cross sectionally at KRT-start (n = 248), and (ii) longitudinally over the 2-years preceding KRT start (n = 157; 331 patient-visits). Longitudinal analyses with mixed-effects models estimated associations of modifiable CV risk factors with change in carotid intima-media thickness (cIMT) standard deviation score (SDS), pulse wave velocity (PWV-SDS), left ventricular (LV) mass and systolic dysfunction.

Findings

248 patients, age 14.3 (12.2, 16.2) years were evaluated at median 35 (28-114) days before KRT start. Elevated cIMT-SDS and PWV-SDS were present in 43% and 25%, and LV hypertrophy and systolic dysfunction in 49% and 33%. Aortic stiffness and LV hypertrophy significantly increased, especially in the year before KRT start (adjusted odds ratio, OR 0.33, P = 0.002 and OR 0.54, P = 0.01, respectively). 79% of children had >3 modifiable CV risk factors at KRT onset. Diastolic BP and BMI were strongly associated with a linear increase in all CV measures. After controlling for CV risk factors, the time to KRT onset no longer predicted the burden of CV damage.

Interpretation

This comprehensive CV evaluation shows the progressive accrual of modifiable risk factors and a high burden of CV damage in the years preceding KRT onset. CV damage in the pre-KRT period is preventable.

Funding

Supported by EU4Health Programme (101085068) and Kidney Research UK (RP39/2013).

Evidence of increased vascular stiffness and left ventricular hypertrophy in children with cystic kidney disease

BACKGROUND

Cardiovascular disease (CVD) is the most common cause of mortality in chronic kidney disease (CKD). Children with early-onset CKD arguably experience the greatest lifetime CVD burden. We utilized data from the Chronic Kidney Disease in Children Cohort Study (CKiD) to evaluate two pediatric CKD cohorts: congenital anomalies of the kidney and urinary tract (CAKUT) and cystic kidney disease for CVD risks and outcomes.

METHODS

CVD risk factors and outcomes including blood pressures, left ventricular hypertrophy (LVH), left ventricular mass index (LVMI), and ambulatory arterial stiffness index (AASI) scores were evaluated.

RESULTS

Forty-one patients in the cystic kidney disease group were compared to 294 patients in the CAKUT group. Cystic kidney disease patients had higher cystatin-C levels, despite similar iGFR. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) indexes were higher in the CAKUT group, but a significantly higher proportion of cystic kidney disease patients was on anti-hypertensive medications. Cystic kidney disease patients had increased AASI scores and a higher incidence of LVH.

CONCLUSIONS

This study provides a nuanced analysis of CVD risk factors and outcomes including AASI and LVH in two pediatric CKD cohorts. Cystic kidney disease patients had increased AASI scores, higher incidence of LVH, and higher rates of anti-hypertensive medication use which could imply a greater burden of CVD despite similar GFR. Our work suggests that additional mechanisms may contribute to vascular dysfunction in cystic kidney disease, and that these patients may need additional interventions to prevent the development of CVD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Serum cystatin C is associated with peripheral artery stiffness in patients with type 2 diabetes mellitus combined with chronic kidney disease

OBJECTIVE

Cystatin C (CysC) is associated with arterial stiffness. However, its suitability for evaluating patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) remains unclear. We aimed to investigate the relationship between CysC levels and peripheral arterial stiffness (PAS) in patients with T2DM combined with CKD.

METHODS

Participants' arterial stiffness was assessed using brachial-ankle pulse wave velocity (baPWV), and those with a baPWV ≥ 1800 cm/s were included in the PAS group. Additionally, patients were divided into young (18-44 years old), middle-aged (45-59 years old), and older (≥60 years old) groups.

RESULTS

Of 200 patients, 94 (47%) were diagnosed with PAS. Multivariate logistic regression revealed that age, pulse pressure, and CysC levels (odds ratio = 1.525, 95% confidence interval: 1.072-2.168, P = 0.019) were independently correlated with PAS in patients with T2DM combined with CKD. The levels of CysC in different age groups were positively correlated with baPWV, and the correlation was significantly higher in the young group (r = 0.739, P < 0.001) than in the middle-aged (r = 0.329, P < 0.001) and older (r = 0.496, P < 0.001) groups. The multifactor linear regression analysis revealed that CysC was significantly correlated with baPWV in the young group (β = 0.455, P = 0.002).

CONCLUSION

CysC was an independent predictor of PAS in patients with T2DM combined with CKD and was more significantly associated with baPWV in young patients than in middle-aged and older patients. CysC may may be an early predictor of peripheral arteriosclerosis in patients with T2DM combined with CKD.

Serum Cystatin C as a Biomarker for Early Diabetic Kidney Disease and Dyslipidemia in Young Type 1 Diabetes Patients

Background and objectives: This study aimed to assess the clinical significance of serum cystatin C in the early diagnosis of renal injury and its association with dyslipidemia in young T1D patients. Materials and Methods: A total of 779 subjects were evaluated for kidney function by estimating glomerular filtration rate (eGFR) based on serum creatinine (eGFRcreat) and cystatin C (eGFRcys). Results: The median age of study subjects was 16.2 years (2.1;26.4), diabetes duration—5.3 years (0.51;24.0). The median of HbA1c was 8% (5.2;19.9) (64 mmol/mol (33.3;194)); 24.2% of participants had HbA1c < 7% (53 mmol/mol). Elevated albumin excretion rate was found in 13.5% of subjects. The median of cystatin C was 0.8 mg/L (0.33;1.71), the median of creatinine—63 µmol/L (6;126). The median of eGFRcys was lower than eGFRcreat (92 mL/min/1.73 m² vs. 101 mL/min/1.73 m², p < 0.001). A total of 30.2% of all patients were classified as having worse kidney function when using cystatin C vs. creatinine for eGFR calculation. Linear correlations were found between cystatin C and HbA1c, r = −0.088, p < 0.05, as well as cystatin C and HDL, r = −0.097, p < 0.01. Conclusions: This study showed that cystatin C might be used as an additional biomarker of early kidney injury in young patients with T1D.

Cardiovascular Disease Risk Factors in Chronic Kidney Disease in Children

Over the past 2 decades, cardiovascular (CV) disease has been recognized as one of the most important complications of chronic kidney disease (CKD) and one of the leading causes of death in children with advanced CKD and in young adults who developed CKD during childhood. CV abnormalities develop early and progress during the course of CKD in children. Characterization of the prevalence and evolution of CV disease risk factors in progressive CKD is one of the primary aims of the Chronic Kidney Disease in Children study. In this review, we summarize up-to-date findings from the Chronic Kidney Disease in Children study with a focus on traditional and CKD-related CV risk factors and early subclinical markers of cardiac and vascular structure and function. We also discuss the effect of CV risk factors on progression of CKD.

Cystatin C as a biomarker of chronic kidney disease: latest developments

INTRODUCTION

Chronic kidney disease (CKD) is common, occurring in over 10% of individuals globally, and is increasing in prevalence. The limitations of traditional biomarkers of renal dysfunction, such as serum creatinine, have been well demonstrated in the literature. Therefore, augmenting clinical assessment with newer biomarkers, such as serum cystatin C, has the potential to improve disease monitoring and patient care.

AREAS COVERED

The present paper assesses the utility and limitations of serum cystatin C as a biomarker for CKD in light of the current literature.

EXPERT OPINION

Serum cystatin C has been well established as an early and accurate biomarker of CKD that is particularly helpful in patients for whom creatinine is an inadequate marker or for whom more cumbersome methods of glomerular filtration rate (GFR) measurement are impractical. Current research questions are no longer focused on if, but rather when and how often cystatin C should be used in the evaluation of CKD patients. However, transition of all reagents and estimated GFR equations to the newly established International Standard is critical for developing generalizable data.

Myocardial function in fetuses with lower urinary tract obstruction: Is there a cardiac remodeling effect due to renal damage?

OBJECTIVES

Cardiac remodeling due to renal dysfunction may have an impact on myocardial function (MF) of fetuses with lower urinary tract obstruction (LUTO). The aim was to identify possible differences in MF in LUTO fetuses compared with healthy controls and to look for interactions between urine biochemistry and MF indices.

METHODS

This is a cohort study consisting of 31 LUTO fetuses and 45 healthy controls. Subgroups were generated according to intrauterine therapy (group 1: LUTO after therapy, group 2: LUTO without therapy at the time of examination, and group 3: controls). MF indices were measured using pulsed wave tissue Doppler imaging and M-mode. Furthermore, results of fetal urine biochemistry were gathered retrospectively.

RESULTS

Among other findings, right ventricular (RV) e'/a' ratio was lower in group 1 compared with group 3 (p = .050). According to gestational age (GA) level-dependent analysis, RV isovolumetric relaxation time was significantly longer in group 2 compared with group 1 and group 3 at GA level 1 (19 wk of gestation). A significant positive correlation between RV e'/a' ratio and β-2-microglobulin as well as α-1-microglobulin and potassium could be observed.

CONCLUSION

We observed differences in MF and an association between ventricular filling pattern and renal protein secretion in LUTO fetuses. This can be interpreted as a sign of intrauterine cardiac remodeling.

Cardiovascular Disease in Children and Adolescents With Chronic Kidney Disease

The lifespan of children with advanced chronic kidney disease (CKD), although improved over the past 2 decades, remains low compared with the general pediatric population. Similar to adults with CKD, cardiovascular disease accounts for a majority of deaths in children with CKD because these patients have a high prevalence of traditional and uremia-related risk factors for cardiovascular disease. The cardiovascular alterations that cause these terminal events begin early in pediatric CKD. Initially, these act to maintain hemodynamic homeostasis. However, as the disease progresses, these modifications are unable to sustain cardiovascular function in the long term, leading to left ventricular failure, depressed cardiorespiratory fitness, and sudden death. In this review, we discuss the prevalence of the risk factors associated with cardiovascular disease in pediatric patients with CKD, the pathophysiology that stimulates these changes, the cardiac and vascular adaptations that occur in these patients, and management of the cardiovascular risk in these patients.

Application of echocardiographic data in patients with chronic kidney disease

PURPOSE OF REVIEW

Patients with chronic kidney disease (CKD) are at a high risk for cardiovascular events and mortality, particularly heart failure. Echocardiography is the most commonly used diagnostic imaging modality for heart failure. The purpose of this review is to summarize recent literature that demonstrates how echocardiography may be used to define cardiac structure and function in the CKD population and to identify echocardiographic abnormalities that have utility in predicting clinical outcomes in this population.

RECENT FINDINGS

Recent studies have highlighted the high prevalence of echocardiographic abnormalities in this population, and the challenge of identifying specific echocardiographic criteria for heart failure. There have been advances in application of strain echocardiography for evaluating systolic function in patients with normal ejection fraction, understanding pulmonary hypertension and identifying echocardiographic correlates of albuminuria. Additional studies have focused on diastolic dysfunction, left ventricular hypertrophy and echocardiographic findings in children with CKD.

SUMMARY

Recent studies demonstrate the utility of echocardiography in characterizing heart structure and function and in providing potential tools for risk stratification in the high-risk CKD population.