Hypertension and its severity in children with steroid sensitive nephrotic syndrome during remission

Long-term complications in patients with childhood-onset nephrotic syndrome

BACKGROUND

Reports on long-term complications of childhood-onset nephrotic syndrome (NS), such as obesity, osteoporosis, growth failure, and hypertension, are mostly from developed countries not representing South Asian ethnicities. Furthermore, data on cardiovascular health among patients with childhood-onset NS are limited.

METHODS

This was an observational study involving patients attending a tertiary care center. Patients aged 15 years and older were examined for long-term complications and remission of NS at their visit in December 2021. Childhood-onset NS meant onset of NS before 10 years of age. Long-term complications included obesity, growth failure, low bone mineral density (BMD) Z score, hypertension, and increased carotid intima-media thickness (cIMT). Long-term remission was defined as no relapse for the last [Formula: see text] 3 consecutive years without immunosuppressive medication to maintain remission.

RESULTS

Of 101 patients studied (~ 80% with frequent relapsing (FR)/steroid-dependent (SD) NS), the mean age was 17.6 (± 2.4) years at the time of study. Long-term complications were noted in 89.1% of patients which included one or more of the following: obesity (22.7%), growth failure (31.7%), low BMD Z score (53.5%), hypertension (31.7%), and high cIMT (50.5%). Thirty-nine patients (38.6%) were in long-term remission at the time of the study. Growth failure and low BMD Z scores were less frequent in patients with long-term remission compared to those without long-term remission.

CONCLUSIONS

In patients with childhood-onset NS (predominantly FR/SDNS) who were studied at [Formula: see text] 15 years of age, ~ 90% had long-term complications which included high cIMT in 50%. Only ~ 40% were in long-term remission. A higher resolution version of the Graphical abstract is available as Supplementary information.

IPNA clinical practice recommendations for the diagnosis and management of children with steroid-sensitive nephrotic syndrome

Idiopathic nephrotic syndrome is the most frequent pediatric glomerular disease, affecting from 1.15 to 16.9 per 100,000 children per year globally. It is characterized by massive proteinuria, hypoalbuminemia, and/or concomitant edema. Approximately 85-90% of patients attain complete remission of proteinuria within 4-6 weeks of treatment with glucocorticoids, and therefore, have steroid-sensitive nephrotic syndrome (SSNS). Among those patients who are steroid sensitive, 70-80% will have at least one relapse during follow-up, and up to 50% of these patients will experience frequent relapses or become dependent on glucocorticoids to maintain remission. The dose and duration of steroid treatment to prolong time between relapses remains a subject of much debate, and patients continue to experience a high prevalence of steroid-related morbidity. Various steroid-sparing immunosuppressive drugs have been used in clinical practice; however, there is marked practice variation in the selection of these drugs and timing of their introduction during the course of the disease. Therefore, international evidence-based clinical practice recommendations (CPRs) are needed to guide clinical practice and reduce practice variation. The International Pediatric Nephrology Association (IPNA) convened a team of experts including pediatric nephrologists, an adult nephrologist, and a patient representative to develop comprehensive CPRs on the diagnosis and management of SSNS in children. After performing a systematic literature review on 12 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, recommendations were formulated and formally graded at several virtual consensus meetings. New definitions for treatment outcomes to help guide change of therapy and recommendations for important research questions are given.

Diastolic hypertension is associated with proteinuria in pediatric patients

BACKGROUND AND AIMS

Blood pressure lability has been observed in certain cohorts of pediatric patients with variable degrees of proteinuria; however, the impact of proteinuria on blood pressure is not fully elucidated. The objective of our study was to analyze blood pressure and heart rate in pediatric patients with proteinuria.

METHODS

We performed a retrospective chart review of patients (age 1-18) diagnosed with idiopathic nephrotic syndrome, with varying degrees of proteinuria. Blood pressure and heart rate data were analyzed in relation to anthropometric and biochemical parameters. A total of 72 urine sample analyses, along with associated blood pressure measurements, were obtained from the charts of 33 children (males = 25).

RESULTS

Diastolic blood pressure Z-scores were significantly higher in proteinuric patients (urine protein/creatinine >0.02 g/mmol) compared to non-proteinuric patients (P = .006; Cohen-d 0.97 [0.41; 1.53]). Systolic blood pressure was also significantly higher in proteinuric patients (P = .04), but with a less significant effect size (Cohen-d 0.54 [-0.002; 1.08]). Proteinuria (>0.02 g/mmol) was the most significant predictor of diastolic (β = .79, P = .04), but not systolic blood pressure elevation on multivariate analysis.

CONCLUSIONS

We observed a disproportionate increase in diastolic blood pressure vs systolic blood pressure in patients with proteinuria.

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.