Cardiovascular outcomes of Nephrotic syndrome in childhood (CVONS) study: a protocol for prospective cohort study

Disease-Associated Systemic Complications in Childhood Nephrotic Syndrome: A Systematic Review

Introduction

Nephrotic syndrome (NS) is one of the most common childhood kidney diseases. During the active phase, the disease pathogenesis affects various biological functions linked to loss of proteins negatively, which can result in systemic complications. Complications of childhood NS are divided into two categories: disease-associated complications and drug-associated complications. However, complications in pediatric patients with NS, especially disease-associated complications are still limited. Although reported in the literature, information is not comprehensive and needs to be updated. This study aimed to systematically assess systemic complications in children with NS, especially disease-associated complications, to better understand how they impact outcomes.

Methods

We conducted a systematic search of several databases: BioMed Central Pediatrics, PubMed, Google Scholar, the National Library of Medicine, Cochrane Library, CINAHL/EBSCO, British Medical Journal, Science Direct, Scopus, and Elsevier’s ClinicalKey. We followed the PRISMA guidelines to plan, conduct, and report this review. We used the Joanna Briggs Institute’s critical appraisal tools for assuring the quality of the journal articles that were chosen.

Results

Eleven articles concerning complications in childhood NS were analyzed. Systemic disease-associated complications in covered were cardiovascular complications, infections, thyroid-hormone complication, kidney complications, and oral health complications.

Conclusion

NS is marked by heavy proteinuria, hypoalbuminemia, edema, and hyperlipidemia, which can result in systemic disease-associated complications. Cardiovascular complications, infections, thyroid-hormone complications, kidney complications, and oral health complications are the main systemic complications in childhood NS. It is essential that health-care providers prevent these complications for proper maintenance of patients’ health.

Hypoalbuminemia linked to myocardial dysfunction in recent-onset nephrotic syndrome: a cross-sectional case control 3DSTE study

Background

Although myocardial dysfunction in the context of longstanding steroid-resistant nephrotic syndrome (NS) has been the focus of many series, the detection of myocardial involvement in recent-onset NS has not taken sufficient attention. The primary outcome parameter of our study is the detection of myocardial dysfunction in the initial episode of NS (first 4 weeks after the onset), while the secondary outcome parameter is the determination of the best predictor of such dysfunction among systolic blood pressure, diastolic blood pressure, the duration of the initial episode of NS, and biochemical parameters such as serum albumin and cholesterol.

Methods

Forty NS patients during the initial episode of NS (first 4 weeks from the onset) were examined for anthropometric data as well as for serum albumin and cholesterol. Motion-mode echocardiography was used to determine Fractional shortening, while 3D echocardiography was applied to determine left ventricular (LV) ejection fraction (EF) and GLS (global longitudinal strain). Finally, we employed combined conventional and tissue doppler to determine LV E/e′ ratio (ratio of early transmitral inflow and average early diastolic basal septal and mitral annular velocities). Forty healthy, age- and sex-matched controls were enrolled to control advanced echocardiographic parameters.

Results

LV GLS was markedly reduced in cases compared to controls, denoting subtle systolic dysfunction, while, LV E/e′ ratio was significantly higher in cases denoting diastolic dysfunction in early NS. Hypoalbuminemia was found to be the best predictor of both LV GLS and LV E/e′ ratio.

Conclusion

Myocardial dysfunction should be considered in any NS patient even in recent-onset NS, the severity of hypoalbuminemia seems to be the best determinant of this dysfunction either by increasing endothelial dysfunction or through triggering inflammation. Further studies are needed on the mechanism by which hypoalbuminemia induces myocardial dysfunction in NS patients

Atherosclerosis in Chronic Kidney Disease: More, Less, or Just Different?

Patients with chronic kidney disease (CKD) are at an increased risk of premature mortality, mainly from cardiovascular causes. The association between CKD on hemodialysis and accelerated atherosclerosis was described >40 years ago. However, more recently, it has been suggested that the increase in atherosclerosis risk is actually observed in early CKD stages, remaining stable thereafter. In this regard, interventions targeting the pathogenesis of atherosclerosis, such as statins, successful in the general population, have failed to benefit patients with very advanced CKD. This raises the issue of the relative contribution of atherosclerosis versus other forms of cardiovascular injury such as arteriosclerosis or myocardial injury to the increased cardiovascular risk in CKD. In this review, the pathophysiogical contributors to atherosclerosis in CKD that are shared with the general population, or specific to CKD, are discussed. The NEFRONA study (Observatorio Nacional de Atherosclerosis en NEFrologia) prospectively assessed the prevalence and progression of subclinical atherosclerosis (plaque in vascular ultrasound), confirming an increased prevalence of atherosclerosis in patients with moderate CKD. However, the adjusted odds ratio for subclinical atherosclerosis increased with CKD stage, suggesting a contribution of CKD itself to subclinical atherosclerosis. Progression of atherosclerosis was closely related to CKD progression as well as to the baseline presence of atheroma plaque, and to higher phosphate, uric acid, and ferritin and lower 25(OH) vitamin D levels. These insights may help design future clinical trials of stratified personalized medicine targeting atherosclerosis in patients with CKD. Future primary prevention trials should enroll patients with evidence of subclinical atherosclerosis and should provide a comprehensive control of all known risk factors in addition to testing any additional intervention or placebo.

Hypertension in Childhood Nephrotic Syndrome

Arterial hypertension (HTN) is commonly encountered by clinicians treating children with steroid sensitive (SSNS) and steroid resistant nephrotic syndrome (SRNS). Although the prevalence of HTN in SSNS is less documented than in SRNS, recent studies reported high prevalence in both. Studies have estimated the prevalence of HTN in different patient populations with NS to range from 8 to 59.1%. Ambulatory HTN, abnormalities in BP circadian rhythm, and measures of BP variability are prevalent in patients with NS. Multiple mechanisms and co-morbidities contribute to the pathophysiology of HTN in children with NS. Some contributing factors are known to cause acute and episodic elevations in blood pressure such as fluid shifts, sodium retention, and medication side effects (steroids, CNIs). Others are associated with chronic and more sustained HTN such as renal fibrosis, decreased GFR, and progression of chronic kidney disease. Children with NS are more likely to suffer from other cardiovascular disease risk factors, such as obesity, increased measures of arterial stiffness [increased carotid intima-media thickness (cIMT), endothelial dysfunction, increased pulse wave velocity (PWV)], impaired glucose metabolism, dyslipidemia, left ventricular hypertrophy (LVH), left ventricular dysfunction, and atherosclerosis. Those risk factors have been associated with premature death in adults. In this review on HTN in patients with NS, we will discuss the epidemiology and pathophysiology of hypertension in patients with NS, as well as management aspects of HTN in children with NS.