Longitudinal progression trajectory of estimated glomerular filtration rate in children with chronic kidney disease: results from the KNOW-Ped CKD (KoreaN cohort study for Outcomes in patients With Pediatric Chronic Kidney Disease).

Background: The natural course of chronic kidney disease (CKD) progression in children varies according to their underlying conditions. This study aims to identify different patterns of subsequent decline in kidney function and investigate factors associated with different patterns of estimated glomerular filtration rate (eGFR) trajectories. Methods: We analyzed data from the KNOW-Ped CKD (KoreaN cohort study for Outcomes in patients With Pediatric Chronic Kidney Disease), which is a longitudinal, prospective cohort study. A latent class linear mixed model was applied to identify the trajectory groups. Results: In a total of 287 patients, the median baseline eGFR (mL/min/1.73 m2) was 63.3, and the median age was 11.5 years. The eGFR decline rate was -1.54 during a 6.0-year follow-up. The eGFR trajectory over time was classified into four groups. Classes 1 (n = 103) and 2 (n = 11) had a slightly reduced eGFR at enrollment with a stable trend (ΔeGFR, 0.2/year) and a rapid decline eGFR over time (ΔeGFR, -10.5/year), respectively. Class 3 had a normal eGFR (n = 16), and class 4 had a moderately reduced eGFR (n = 157); both these chasses showed a linear decline in eGFR over time (ΔeGFR, -4.1 and -2.4/year). In comparison with classes 1 and 2, after adjusting for age, causes of primary renal disease, and baseline eGFR, nephrotic-range proteinuria was associated with a rapid decline in eGFR (odds ratio, 8.13). Conclusion: We identified four clinically relevant subgroups of kidney function trajectories in children with CKD. Most children showed a linear decline in eGFR; however, there are different patterns of eGFR trajectories.

Clinical course of post-kidney transplant Schimke immuno-osseous dysplasia.

BACKGROUND: Schimke immuno-osseous dysplasia (SIOD) is a rare systemic disease characterized by short stature, proteinuria, and recurrent infections. Patients usually have spondyloepiphyseal dysplasia, and progressive steroid-resistant nephropathy that leads to kidney failure. However, their clinical course after kidney transplantation (KT) is not yet well known. Here, we present our experience with cases of SIOD treated at our institute. CASE PRESENTATION: Since 2014, three children have been diagnosed with nephropathy resulting from SIOD. They presented with proteinuria in the nephrotic range at 7, 5, and 3 years of age. Focal segmental glomerulosclerosis was confirmed and progressed to kidney failure approximately 2 years after proteinuria was detected. These patients underwent living-donor KT from their parents. After KT, Case 1 lost his graft within 7 months due to multi-organ failure caused by disseminated adenovirus infection and died. Case 2 experienced graft failure 5 years after KT due to acute rejection from poor compliance. In Case 3, the allograft was still functioning 6 years after KT with low-dose tacrolimus single medication (trough level < 5 ng/mL). Extra-renal manifestations progressed regardless of KT, namely, right renal vein thrombosis and pulmonary hypertension in Case 1, severe bilateral hip dysplasia and Moyamoya syndrome in Case 2, and neutropenia and thrombocytopenia in Case 3, in addition to recurrent infection. CONCLUSION: In SIOD patients, KT is complicated with recurrent infections due to their inherent immune dysfunction. Additionally, extra-renal symptoms may render the patients morbid despite the recovery of kidney function.

Corrigendum: Mineral bone disorder in children with chronic kidney disease: data from the KNOW-Ped CKD (Korean cohort study for outcome in patients with pediatric chronic kidney disease) study.

[This corrects the article DOI: 10.3389/fped.2023.994979.].

Mineral bone disorder in children with chronic kidney disease: Data from the KNOW-Ped CKD (Korean cohort study for outcome in patients with pediatric chronic kidney disease) study.

Background: Children with chronic kidney disease (CKD) are at high risk of mineral bone disorder (MBD), which leads to fractures, growth retardation, and cardiovascular disease. We aimed to comprehensively understand the relationship between renal function and factors related to MBD and evaluate the prevalence and distribution characteristics of MBD, specifically among Korean patients from the KNOW-PedCKD cohort. Methods: From the baseline data of the KNOW-PedCKD cohort, we examined the prevalence and distribution of MBD in 431 Korean pediatric CKD patients, including the level of corrected total calcium, serum phosphate, serum alkaline phosphatase, serum intact parathyroid hormone (iPTH), fibroblast growth factor 23 (FGF-23), serum vitamin D, fractional excretion of phosphate (FEP), and bone densitometry Z-scores. Results: The median serum calcium level remained relatively normal regardless of the CKD stage. The levels of 1,25-dihydroxy vitamin D, urine calcium-to-creatinine ratio, and bone densitometry Z-score significantly decreased with advancing CKD stage, while those of serum phosphate, FGF-23, and FEP significantly increased with CKD stage. The prevalence of hyperphosphatemia (17.4%, 23.7%, and 41.2% from CKD stages 3b, 4, and 5, respectively) and hyperparathyroidism (37.3%, 57.4%, 55.3%, and 52.9% from CKD stages 3a, 3b, 4, and 5, respectively) significantly increased with the CKD stage. Prescriptions of medications, such as calcium supplements (39.1%, 42.1%, 82.4%), phosphate binders (39.1%, 43.4%, 82.4%), and active vitamin D (21.7%, 44.7%, and 64.7%) significantly increased with CKD stage 3b, 4, and 5, respectively. Conclusions: The results demonstrated the prevalence and relationship of abnormal mineral metabolism and bone growth according to CKD stage in Korean pediatric CKD patients for the first time.

The compatibility of new blood pressure reference values for Korean children and adolescents with the US reference: the Korean Working Group of Pediatric Hypertension.

BACKGROUND: Childhood hypertension is associated with hypertension and metabolic syndrome in adulthood. Since the definition of childhood hypertension is based on the distribution of normative blood pressure (BP), a reference range is essential to create hypertension guidelines for children. We aimed to investigate the compatibility of the new Korean BP reference with the United States (US) BP reference based on the 2017 Clinical Practice Guideline. METHODS: We compared the new Korean reference BP values for children and adolescents aged 10 to 17 years with those in the 2017 Clinical Practice Guidelines. We also analyzed the differences in the prevalence of hypertension in Korean children and adolescents when reference value was applied. Considering Korean and US BP references together, linear trend lines were sought. RESULTS: Systolic BP (SBP) and diastolic BP (DBP) values in 95th percentiles showed no significant differences between the two BP references. Applying the two reference values, there was no significant difference in the prevalence of elevated BP and a combination of elevated BP and hypertension. Combining the Korean and US BP values and plotting them against age, approximate lines for the 90th and 95th SBP and DBP percentiles were observed. CONCLUSIONS: The BP values of the new Korean BP reference were similar to those of the US BP reference; they were reliable and interchangeable.

Correction: Park et al. Genetic Study in Korean Pediatric Patients with Steroid-Resistant Nephrotic Syndrome or Focal Segmental Glomerulosclerosis. J. Clin. Med. 2020, 9, 2013.

In the original article [...].

Effects of tacrolimus intrapatient variability and CYP3A5 polymorphism on the outcomes of pediatric kidney transplantation.

BACKGROUND: The intrapatient variability (IPV) of tacrolimus (Tac) is associated with the long-term outcome of kidney transplantation. The CYP3A single-nucleotide polymorphism (SNP) may affect the IPV of Tac. We investigated the impact of IPV and genetic polymorphism in pediatric patients who received kidney transplantation. METHODS: A total of 202 pediatric renal transplant recipients from 2000 to 2016 were analyzed retrospectively. The IPV was calculated between 6 and 12 months after surgery. Among these patients, CYP3A5 polymorphism was analyzed in 67 patients. RESULTS: The group with high IPV had a significantly higher rate of de novo donor-specific human leukocyte antigen antibodies (dnDSA) development (35.7% vs. 16.7%, p = .003). The high IPV group also had a higher incidence of T-cell-mediated rejection (TCMR; p < .001). The high IPV had no significant influence on Epstein-Barr virus, cytomegalovirus, and BK virus viremia but was associated with the incidence of posttransplant lymphoproliferative disorders (p = .003). Overall, the graft survival rate was inferior in the high IPV group (p < .001). The CYP3A5 SNPs did not significantly affect the IPV of Tac. In the CYP3A5 expressor group, however, the IPV was significantly associated with the TCMR-free survival rate (p < .001). CONCLUSION: The IPV of Tac had a significant impact on dnDSA development, occurrence of acute TCMR, and graft failure in pediatric patients who received renal transplantation. CYP3A5 expressors with high IPV of Tac showed worse outcomes, while the CYP3A5 polymorphism had no impact on IPV of Tac.

Baseline characteristics of participants enrolled in the KoreaN cohort study for Outcomes in patients With Pediatric Chronic Kidney Disease (KNOW-Ped CKD).

BACKGROUND: We developed the KoreaN cohort study for Outcomes in patients With Pediatric Chronic Kidney Disease (KNOW-Ped CKD) as a subcohort of KNOW-CKD to investigate the different characteristics of pediatric CKD between countries and races. METHODS: Children aged younger than 18 years with stage 1 ~ 5 CKD were recruited at seven major pediatric nephrology centers in Korea. Blood and urine samples, as well as demographic and clinical data, were collected. From 2011 to 2016, 458 children were enrolled, and the baseline profiles of 437 children were analyzed. RESULTS: The median age of the cohort was 10.9 years old, and 68.0% were males. The median estimated glomerular filtration rate was 53.1 mL/min/1.73 m2. The most common etiology of CKD was congenital anomalies of the kidney and urinary tract (42.6%), followed by glomerulopathies (25.6%). CONCLUSION: We report a cross-sectional analysis of the overall baseline characteristics such as age, CKD stage, and underlying kidney disease of the KNOW-Ped CKD. The cohort will be longitudinally followed for ten years. "A higher resolution version of the Graphical abstract is available as Supplementary information."

Gordon syndrome caused by a CUL3 mutation in a patient with short stature in Korea: a case report.

Objectives: Gordon syndrome (GS), also known as pseudohypoaldosteronism type II, is a rare tubular disease characterized by hypertension, hyperkalemia, and metabolic acidosis. Its causative genes are CUL3, KLHL3, WNK1, and WNK4, and they are associated with varying severity of the disease. Herein, we report the first case of GS caused by a CUL3 mutation in a patient with short stature in Korea.Case presentation: A 7-year-old boy had hypertension, metabolic acidosis, and persistent hyperkalemia, which were initially detected during the evaluation of short stature. He was born small for gestational age at late preterm gestation. Laboratory test findings showed hyperkalemia with low trans-tubular potassium gradient, hyperchloremic metabolic acidosis with a normal anion gap, and low plasma renin levels. Genetic analysis revealed a heterozygous de novo mutation in the CUL3 gene (c.1377+1G > C in intron 9). Thus, a diagnosis of GS was made. The results of the endocrine function test (including growth hormone stimulation tests) were normal. After thiazide treatment, the patient's electrolyte levels were normalized. However, he presented with persistent hypertension and short stature.Conclusions: GS should be considered in children with short stature, hypertension, and hyperkalemia, and early treatment may reduce complications.

Characteristics of pediatric rhabdomyolysis and the associated risk factors for acute kidney injury: a retrospective multicenter study in Korea.

BACKGROUND: The clinical features of pediatric rhabdomyolysis differ from those of the adults with rhabdomyolysis; however, multicenter studies are lacking. This study aimed to investigate the characteristics of pediatric rhabdomyolysis and reveal the risk factors for acute kidney injury (AKI) in such cases. METHODS: This retrospective study analyzed the medical records of children and adolescents diagnosed with rhabdomyolysis at 23 hospitals in South Korea between January 2007 and December 2016. RESULTS: Among 880 patients, those aged 3 to 5 years old composed the largest subgroup (19.4%), and all age subgroups were predominantly male. The incidence of AKI was 11.3%. Neurological disorders (53.6%) and infection (39.0%) were the most common underlying disorder and cause of rhabdomyolysis, respectively. The median age at diagnosis in the AKI subgroup was older than that in the non-AKI subgroup (12.2 years vs. 8.0 years). There were no significant differences in body mass index, myalgia, dark-colored urine, or the number of causal factors between the two AKI-status subgroups. The multivariate logistic regression model indicated that the following factors were independently associated with AKI: multiorgan failure, presence of an underlying disorder, strong positive urine occult blood, increased aspartate aminotransferase and uric acid levels, and reduced calcium levels. CONCLUSIONS: Our study revealed characteristic clinical and laboratory features of rhabdomyolysis in a Korean pediatric population and highlighted the risk factors for AKI in these cases. Our findings will contribute to a greater understanding of pediatric rhabdomyolysis and may enable early intervention against rhabdomyolysis-induced AKI.

Intellectual Functioning of Pediatric Patients with Chronic Kidney Disease: Results from the KNOW-Ped CKD.

BACKGROUND: Chronic kidney disease (CKD) has a negative impact on growth and development in children and is a risk factor for neurocognitive impairment; however, there is limited research on the cognitive function of children and adolescents with CKD. This study therefore aimed to investigate the mean intelligence and risk factors for low intelligence in children and adolescents with CKD. METHODS: Eighty-one patients with CKD under 18 years old were included in the KoreaN cohort study for Outcomes in patients With Pediatric Chronic Kidney Disease (KNOW-Ped CKD). Participants completed either the Wechsler Intelligence Scale for Children (6-16 years), or Wechsler Adult Intelligence Scale (> 16 years). RESULTS: The mean full-scale intelligence quotient (IQ) was 91 ± 19; 24.7% of participants scored a full-scale IQ below 80. Participants with a short stature (height Z scores < -1.88), failure to thrive (weight Z scores < -1.65), more severe CKD stage (≥ IIIb), longer duration of CKD (≥ 5 years), and those who were Medicare or Medicaid beneficiaries, had significantly lower mean full-scale IQs. CONCLUSION: On linear regression analysis, the association between the full-scale IQ, and longer duration of CKD and growth failure, remained significant after controlling for demographic and clinical variables. It is therefore necessary to investigate cognitive impairment in pediatric patients with CKD who exhibit growth failure or for a longer postmorbid period. It is believed that early interventions, such as kidney transplantation, will have a positive effect on IQ in children with CKD, as the disease negatively affects IQ due to poor glomerular filtration rate over time. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02165878.

Incidence of and risk factors for short stature in children with chronic kidney disease: results from the KNOW-Ped CKD.

BACKGROUND: Preserving optimal growth has long been a significant concern for children with chronic kidney disease (CKD). We aimed to examine the incidence of and risk factors for short stature in Asian pediatric patients with CKD. METHODS: We analyzed growth status by height, weight, and body mass index (BMI) standard deviation scores (SDSs) for 432 participants in the KoreaN cohort study for Outcome in patients With Pediatric Chronic Kidney Disease. RESULTS: The median height, weight, and BMI SDSs were - 0.94 (interquartile range (IQR) - 1.95 to 0.05), - 0.58 (IQR - 1.46 to 0.48), and - 0.26 (IQR - 1.13 to 0.61), respectively. A high prevalence of short stature (101 of 432 patients, 23.4%) and underweight (61 of 432 patients, 14.1%) was observed. In multivariable logistic regression analysis, CKD stages 4 and 5 (adjusted odds ratio (aOR) 2.700, p = 0.001), onset before age 2 (aOR 2.928, p < 0.0001), underweight (aOR 2.353, p = 0.013), premature birth (aOR 3.484, p < 0.0001), LBW (aOR 3.496, p = 0.001), and low household income (aOR 1.935, p = 0.030) were independent risk factors associated with short stature in children with CKD. CONCLUSIONS: Children with CKD in Korea were shorter and had lower body weight and BMI than the general population. Short stature in children with CKD was most independently associated with low birth weight, followed by premature birth, onset before age 2, CKD stages 4 and 5, underweight, and low household income. Among these, underweight is the only modifiable factor. Therefore, we suggest children with CKD should be carefully monitored for weight, nutritional status, and body composition to achieve optimal growth.

Mortality in Children Treated With Maintenance Peritoneal Dialysis: Findings From the International Pediatric Peritoneal Dialysis Network Registry.

RATIONALE & OBJECTIVE: Research on pediatric kidney replacement therapy (KRT) has primarily focused on Europe and North America. In this study, we describe the mortality risk of children treated with maintenance peritoneal dialysis (MPD) in different parts of the world and characterize the associated demographic and macroeconomic factors. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: Patients younger than 19 years at inclusion into the International Pediatric Peritoneal Dialysis Network registry, who initiated MPD between 1996 and 2017. EXPOSURE: Region as primary exposure (Asia, Western Europe, Eastern Europe, Latin America, North America, and Oceania). Other demographic, clinical, and macroeconomic (4 income groups based on gross national income) factors also were studied. OUTCOME: All-cause MPD mortality. ANALYTICAL APPROACH: Patients were observed for 3 years, and the mortality rates in different regions and income groups were calculated. Cause-specific hazards models with random effects were fit to calculate the proportional change in variance for factors that could explain variation in mortality rates. RESULTS: A total of 2,956 patients with a median age of 7.8 years at the start of KRT were included. After 3 years, the overall probability of death was 5%, ranging from 2% in North America to 9% in Eastern Europe. Mortality rates were higher in low-income countries than in high-income countries. Income category explained 50.1% of the variance in mortality risk between regions. Other explanatory factors included peritoneal dialysis modality at start (22.5%) and body mass index (11.1%). LIMITATIONS: The interpretation of interregional survival differences as found in this study may be hampered by selection bias. CONCLUSIONS: This study shows that the overall 3-year patient survival on pediatric MPD is high, and that country income is associated with patient survival.

Lower albumin level and longer disease duration are risk factors of acute kidney injury in hospitalized children with nephrotic syndrome.

BACKGROUND: Children with nephrotic syndrome (NS) are at an increased risk of acute kidney injury (AKI) and the incidence of AKI in this population is reportedly increasing. This study aimed to investigate the incidence, clinical profiles, and risk factors of AKI in hospitalized children with NS through a nationwide study. METHODS: This retrospective multicenter study included 14 pediatric nephrology centers in Korea. From 2013 to 2017, a total of 814 patients with idiopathic NS were cared for at participating centers. Among them, 363 patients were hospitalized for NS and investigated in this study. RESULTS: A total of 363 children with NS were hospitalized 574 times. AKI occurred in 93 admissions (16.2%) of 89 patients: 30 (32.3%) stage 1; 24 (25.8%) stage 2; and 39 (41.9%) stage 3. Multivariate logistic regression analysis showed that longer disease duration, lower albumin level, and methylprednisolone pulse treatment were significantly associated with AKI development in hospitalized children with NS. AKI was associated with a longer hospital stay than non-AKI (median 10 vs. 7 days, P = 0.001). Among 93 admissions, 85 (91.4%) episodes recovered from AKI without complication, whereas 6 (6.5%) progressed to advanced chronic kidney disease (CKD). CONCLUSIONS: AKI is not uncommon in hospitalized children with NS, and its incidence in this nationwide study was 16.2%. Risk factors for AKI in hospitalized children with NS include longer disease duration, lower albumin level, and methylprednisolone pulse therapy. Pediatric NS patients with these characteristics should be under more strict scrutiny for the occurrence of AKI. Graphical abstract.

Clinical Relevance of Fluid Volume Status Assessment by Bioimpedance Spectroscopy in Children Receiving Maintenance Hemodialysis or Peritoneal Dialysis.

Bioimpedance spectroscopy (BIS) is a noninvasive method used to evaluate body fluid volume status in dialysis patients, but reports on its effectiveness in pediatrics are scarce. We investigated the correlation between BIS and clinical characteristics and identified the changes in patients whose dialysis prescription was modified based on BIS. The medical records of children on maintenance dialysis who had undergone BIS between 2017 and 2019 were reviewed. Of the 49 patients, 14 were overhydrated, based on the >15% proportion of overhydration relative to extracellular water (OH/ECW) measured by BIS. Intake of ≥two antihypertensive medications was noted in the majority (85.7%) of children with fluid overload and only in 48.6% of those without fluid overload (p = 0.017). Elevated blood pressure despite medication use was significantly more common in patients with fluid overload than in those without fluid overload (78.6% vs. 45.7%, p = 0.037). Of the 14 overhydrated children, 13 (92.9%) had significant changes in body weight, OH/ECW, the number of antihypertensive drugs, left ventricular end-diastolic diameter, and cardiothoracic ratio after the change in dialysis prescription. BIS is a useful and noninvasive method to assess fluid status in dialysis children. Long-term follow-up and correlation with a more objective clinical indicator of fluid overload is necessary to verify the clinical effectiveness of BIS.

Left-ventricular diastolic dysfunction in Korean children with chronic kidney disease: data from the KNOW-Ped CKD study.

BACKGROUND: Cardiovascular disease (CVD) is the most common cause of mortality in pediatric chronic kidney disease (CKD) patients. Left ventricular (LV) hypertrophy (LVH) is associated with LV diastolic dysfunction (LVDD) development and is used as an early marker of CVD in pediatric CKD. This study aimed to assess the prevalence and risk factors of LVDD and the association between LVH and LVDD in Korean pediatric CKD patients. METHODS: Data were collected using the baseline data of the Korean cohort study for outcome in patients with pediatric chronic kidney disease, a nationwide, 10-year, prospective, observational cohort study of pediatric CKD. A total of 244 patients were included in the final analysis. Two-dimensional echocardiography and tissue Doppler images were used to evaluate LVH and LVDD. LVH was defined as an LV mass index (LVMI) ≥38 g/m2.7 and LV-wall thickness z-score > 1.64. LVDD was defined as a mitral peak velocity of early filling to early diastolic mitral annular velocity (E/E') > 14. Univariate and multivariate logistic regression analyses were performed to evaluate risk factors of LVDD. RESULTS: In this study, the male-to-female ratio was 2.2 (168:76) and median age was 11.2 years. The average estimated glomerular filtration rate was 57.4 ml/min/1.73 m2, and no patients received renal replacement therapy. The mean value of LVMI and E/E' was 37.0 g/m2.7 and 7.4, respectively. The prevalence of LVH was 40.1 and 17.4% by LVMI ≥38 g/m2.7 and LV-wall thickness z-score, respectively. The prevalence of LVDD was 4.5%, and patients with LVH showed greater risk of LVDD (odds ratio 7.3, p = 0.012). In the univariate analysis, young age, low hemoglobin level, higher LVMI, and higher LV-wall thickness z-score were associated with LVDD. In the multivariate analysis, young age, low hemoglobin level, and higher LV-wall thickness z-score were independently associated with LVDD. CONCLUSION: This study shows that LVH patients have a greater risk of LVDD and that anemia is the only modifiable risk factor for LVDD in Korean pediatric CKD patients.

Case of catastrophic antiphospholipid syndrome presenting as neuroretinitis and vaso-occlusive retinopathy.

BACKGROUND: Ocular involvement in catastrophic antiphospholipid syndrome (CAPS), a rare, life-threatening form of antiphospholipid syndrome (APS) that results in multiorgan failure and a high mortality rate, has rarely been reported. CASE PRESENTATION: A 15-year-old girl presented with sudden vision blurring in both eyes. She had marked optic disc swelling and macular exudates in the right eye and intra-arterial white plaques, a few retinal blot hemorrhages, and a white ischemic retina in the left eye. Systemic examination revealed she had acute kidney injury with thrombotic microangiopathy (TMA), multiple cerebral infarcts, valvular dysfunction, and a high titer of triple aPL. Thus, she was diagnosed with CAPS involving the brain, eyes, heart, and kidneys. Plasma exchange and the administration of glucocorticoids, immunoglobulin, warfarin, and rituximab brought a sustained recovery of the TMA, visual symptoms, and echocardiographic findings. CONCLUSIONS: Ocular involvement of both vaso-occlusive retinopathy, an APS-related thrombotic microangiopathy, and neuroretinitis, a non-thrombotic microangiopathy, can occur as an initial presentation of CAPS.

Renal Syndromic Hearing Loss Is Common in Childhood-onset Chronic Kidney Disease.

BACKGROUND: Hearing loss (HL) in children may adversely affect their development. HL is more prevalent in patients with chronic kidney disease (CKD) than in the general population. This study evaluated the prevalence of HL and its underlying diseases in patients with childhood-onset in CKD. METHODS: In this retrospective study of a tertiary referral center, childhood-onset CKD patients (stage 2-5, age at onset of renal symptom < 18 years) were recruited. We referred to the "renal" syndromic HL as cases with genetic or syndromic diseases, or extra-renal anomalies in addition to HL and CKD. RESULTS: A total of 421 patients (male:female = 279:142) were reviewed according to the causes of CKD: congenital anomalies of the kidney and urinary tract (CAKUT; n = 184, 43.7%), glomerulopathies (GP; n = 105, 24.9%), cystic kidney diseases (CYST; n = 39, 9.3%), perinatal problems (PP; n = 29, 6.9%), and others (n = 64, 15.2%). HL was detected in 82 (19.5%) patients, including 51 (12.1%) patients with sensorineural hearing loss (SNHL), 30 (7.1%) with conductive hearing loss (CHL), and 1 patient with mixed HL. The prevalence of HL in each group was as follows: 16.8% in the CAKUT group, 28.6% in the GP group, 12.8% in the CYST group, 24.1% in the PP group, and 14.1% in the others group. HL was more common in higher CKD stages, especially CHL in end-stage renal disease. SNHL was more prevalent in CKD from GP. Of the 82 patients with HL, 50% had renal syndromic HL: 58.8% of SNHL and one-third of CHL were renal syndromic HL. CONCLUSION: One-fifth of the childhood-onset CKD had HL. Collectively, renal syndromic HL comprised half of the HL in this study. To improve the quality of life in patients with childhood-onset CKD, we suggest that HL should be considered, requiring surveillance, and if necessary, early intervention.