Indirect signs of infravesical obstruction on voiding cystourethrography improve post-neonatal posterior urethral valves detection rate.

OBJECTIVES: To identify the diagnostic performance of clinical and radiological signs (on voiding cystourethrography [VCUG]) to detect posterior urethral valves (PUV) in the post-neonatal period. MATERIALS AND METHODS: One hundred eighteen males (median age = 0.8 years, range = 1 month-14 years, 48 toilet-trained) undergoing VCUG in a 2-year period were prospectively enrolled. Direct (dilated posterior urethra) and indirect (hypertrophied bladder neck, musculus interuretericus hypertrophy, and trabeculated appearance of the bladder wall) PUV signs on VCUG were assessed. Uroflowmetry was defined pathological by patterns suggesting infravesical obstruction. RESULTS: Twenty-two patients with direct, 28 with indirect PUV signs on VCUG, and one with normal VCUG but persisting micturition symptoms with pathological uroflowmetry underwent urethrocystoscopy and in 43/51 a PUV diagnosis was made (n = 22, 51.2%, with direct PUV signs). In 8/28 patients with indirect signs, PUV were not confirmed. Among non-toilet-trained patients, none of the clinical signs/symptoms was associated with PUV while among toilet-trained patients only pathological uroflowmetry (odds ratio, OR = 4.0 [95% confidence interval:1.2-13.2; p = 0.02]) and pathological uroflowmetry with history of urinary tract infection (OR = infinity) were significantly associated with PUV. Significant associations with PUV of direct and indirect signs on VCUG were found both in toilet-trained and non-toilet trained patients. Direct PUV sign had 100% specificity and sensitivity while indirect PUV signs showed sensitivity = 58.1% and specificity = 89.3%. The absence of any radiological sign had a negative predictive value = 98.5%. CONCLUSION: Only half of patients with endoscopy-confirmed PUV presents with direct sign of PUV on VCUG. Accounting for indirect PUV signs on VCUG and pathological uroflowmetry (in toilet-trained children) could improve the PUV detection rate. CLINICAL RELEVANCE STATEMENT: Indirect radiological PUV signs should be valorized when interpreting VCUG to improve the PUV detection rate. The absence of any radiological PUV (direct and indirect) sign on VCUG excludes PUV with a very high negative predictive value. KEY POINTS: • Worldwide agreement is that a non-dilated urethra on voiding cystourethrography excludes obstruction. • Half of patients with posterior urethral valves have non-dilated urethra on voiding cystourethrography. • Accounting for indirect signs of posterior urethral valves on voiding cystourethrography improves the diagnostic performance.

Clinical implications of primary "occult" vesicoureteral reflux in male children.

OBJECTIVES: To compare characteristics and outcomes of vesicoureteral reflux (VUR) detected solely on isotopic cystography (IC) ("occult" VUR) with voiding cystourethrography (VCUG)-detected VUR. MATERIALS AND METHODS: Between 2015 and 2020, we retrospectively enrolled all male children first undergoing VCUG and, if negative, IC in the same session. Kidney injury (KI) was defined by abnormal estimated glomerular filtration rate and/or blood pressure and/or proteinuria. RESULTS: We enrolled 421 males with a median age of 3 months and a follow-up of 5.3 years. None exhibited KI initially, but 10% of those with VUR developed KI during follow-up. Two hundred and twenty-two patients (52.7%) did not show VUR, 152 (36.1%) had VCUG-diagnosed VUR, and 47 (11.2%) had occult VUR. Therefore, 47/199 patients (23.6%) with VUR had occult VUR. Among these, 34/47 (72.3%) had dilated VUR, and 22/47 (46.8%) exhibited split renal function < 45% and/or scar (scintigraphic damage). Compared to patients with occult VUR, those with VCUG-diagnosed VUR showed a similar prevalence of febrile urinary tract infection (fUTI) before and after VUR diagnostics and KI at the last follow-up but a higher prevalence of dilated VUR, of scintigraphic damage, and underwent surgery more frequently. At multiple logistic regression analysis, patients with VCUG-diagnosed VUR presented an increased risk of fUTI either before or after VUR diagnosis and of KI, while patients with occult VUR presented an increased risk of fUTI before (and among patients with dilated VUR also after) VUR diagnosis and of KI. CONCLUSION: Occult VUR affects 23.6% of male children with VUR with a non-negligible risk of VUR-associated KI and fUTI. IC could select, among males with recurrent fUTIs and negative VCUG, those requiring surgery for a possible dilated occult VUR. CLINICAL RELEVANCE STATEMENT: Vesicoureteral reflux may be overlooked in 25% of boys during VCUG, yet they are at risk of fUTIs and KI. In case of recurrent infections post-negative cystourethrography, IC could detect occult reflux, guiding surgical intervention.

Association of HDL-Cholesterol, hypertension and left ventricular hypertrophy in youths with overweight or obesity.

BACKGROUND AND AIM: To evaluate the relationship between HDL-Cholesterol (HDL-C), hypertension, and left ventricular hypertrophy (LVH) in a large sample of Caucasian youths with overweight/obesity (OW/OB). METHODS AND RESULTS: A cross-sectional multicenter study was performed in 1469 youths (age 6-16 years) with OW/OB observed in the period 2016-2020. An additional independent sample of 244 youths with an echocardiographic evaluation, observed in a single center was analyzed. The sample was divided in six quantiles (Q) of HDL-C: Q1: >56, Q2: ≤56 > 51, Q3: ≤51 > 45, Q4: ≤45 > 41, Q5: ≤41 > 39, Q6: <39 mg/dL. The nadir of the relationship was identified in youths in the first quantile. Among HDL-Cholesterol quantiles the distribution of hypertension was non-linear with a percentage of 25.0%, 40.1%, 33.6%, 31.3%, 35.2% and 39.7% in the six quantiles, respectively. The percentage of LVH was 21.8%, 43.6%, 48.8%, 35.5%, 38.5% and 52.0% in the six quantiles, respectively. The highest odds [95%Cl] of hypertension were 2.05 (1.33-3.16) (P < 0.01) in Q2, 1.67 (1.10-2.55) (P < 0.05) in Q3 and 1.59 (1.05-2.41) (P < 0.05) in Q6 vs Q1. The odds of LVH were 3.86 (1.15-10.24) (P < 0.05) in Q2, 4.16 (1.58-10.91) (P < 0.05) in Q3 and 3.60 (1.44-9.02) (P < 0.05) in Q6 vs Q1, independently by centers, age, sex, prepubertal stage, and body mass index. CONCLUSION: Contrary to the common belief, the present study shows that high levels of HDL-C may be not considered a negative predictor of hypertension and LVH, two risk factors for future CV disease.

The dual role of body mass index on Juvenile Idiopathic Arthritis course: a pediatric experience.

Despite the well-known role of obesity as risk factor for Juvenile Idiopathic Arthritis (JIA) severity, emerging but limited evidence suggested a similar role for underweight. We investigated the role of body mass index (BMI) across its full spectrum in a cohort of children with JIA.We retrospectively studied 113 children with JIA classified according to the International League of Association for Rheumatology (ILAR) criteria attending our Rheumatology Clinic. The patients underwent a comprehensive evaluation including both clinical and biochemical assessments. According to BMI Z-score, the cohort was divided into five groups as underweight, normal weight, overweight (OW), obesity (OB), and severe OB. Disease activity was calculated by Juvenile Arthritis Disease Activity Score 10 (JADAS-10) joint reduced count and relapses were defined according to Wallace criteria.The mean age of the cohort was 7.43 ± 4.03 years. The prevalence of underweight, normal weight, OW, OB, and severe OB was 7.2%, 54.1%, 10.8%, 17.1%, and 10.8%, respectively. Significant higher ferritin levels and erythrocyte sedimentation rate values were found in patients with severe OB and underweight compared to subjects belonging to normal weight, OW, and OB groups. A greater JADAS-10 score was observed in underweight patients and in those with severe OB than other groups. The relapse rate was higher in patients with severe OB and underweight compared to other groups.          Conclusions: Both underweight and OB might negatively affect JIA course. Weight control is fundamental in children with JIA to avoid a more unfavourable course of the disease. What is Known: • Obesity represents a well-known risk factor for JIA severity. • The role of underweight in children with JIA is still poorly explored. What is New: • As observed in children with obesity, underweight young patients with JIA seem to experience a more severe JIA course. • Healthy lifestyle promotion in children with JIA is a crucial step in the management of the disease.

Kidney function evaluation in children and adolescents with obesity: a not-negligible need.

The role of obesity as risk factor for chronic kidney disease (CKD) has been well-recognized. As previously demonstrated in adults, emerging data highlighted the relevant impact of obesity on renal function since childhood. As a matter of fact, obesity also affects renal health through a complex pathogenic mechanism in which insulin resistance (IR) plays a pivotal role. Worthy of note, the vicious interplay among obesity, IR, and renal hemodynamics clinically translates into a plethora of kidney function impairments potentially leading to CKD development. Therefore, renal injury needs to be added to the well-known spectrum of cardiometabolic obesity comorbidities (e.g., type 2 diabetes, IR, metabolic syndrome, cardiovascular disease). CONCLUSION: Taking this into account, a careful and timely monitoring of kidney function should not be neglected in the global assessment of children with obesity. We aimed to provide a comprehensive overview on the relevance of kidney evaluation in children with obesity by shedding lights on the intriguing relationship of obesity with renal health in this at-risk population. WHAT IS KNOWN: • Obesity has been found to be a risk factor for chronic kidney disease. • Unlike adults, pediatric data supporting the association between obesity and renal function are still limited. WHAT IS NEW: • As observed in adults, obesity might affect renal function since childhood. • Kidney function should be carefully evaluated in children with obesity.

Acute kidney injury in children hospitalised for febrile urinary tract infection.

AIM: To determine (i) prevalence and the risk factors for acute kidney injury (AKI) in children hospitalised for febrile urinary tract infection (fUTI) and (ii) role of AKI as indicator of an underlying VUR. AKI, in fact, is favoured by a reduced nephron mass, often associated to VUR. METHODS: This retrospective Italian multicentre study enrolled children aged 18 years or younger (median age = 0.5 years) discharged with a primary diagnosis of fUTI. AKI was defined using Kidney Disease/Improving Global Outcomes serum creatinine criteria. RESULTS: Of 849 children hospitalised for fUTI (44.2% females, median age 0.5 years; IQR = 1.8), 124 (14.6%) developed AKI. AKI prevalence rose to 30% in the presence of underlying congenital anomalies of the kidney and urinary tract (CAKUT). The strongest AKI predictors were presence of CAKUT (OR = 7.5; 95%CI: 3.8-15.2; p = 9.4e-09) and neutrophils levels (OR = 1.13; 95%CI: 1.08-1.2; p = 6.8e-07). At multiple logistic regression analysis, AKI during fUTI episode was a significant indicator of VUR (OR = 3.4; 95%CI: 1.7-6.9; p = 0.001) despite correction for the diagnostic covariates usually used to assess the risk of VUR after the first fUTI episode. Moreover, AKI showed the best positive likelihood ratio, positive predictive value, negative predictive value and specificity for VUR. CONCLUSION: AKI occurs in 14.6% of children hospitalised for fUTI and is a significant indicator of VUR.

Kidney damage predictors in children with metabolically healthy and metabolically unhealthy obesity phenotype.

BACKGROUND: Obesity and kidney damage have been closely linked in adults, but little is still known in childhood. OBJECTIVE: To identify predictors of kidney damage in children with metabolically healthy (MHO) and metabolically unhealthy (MUO) obesity phenotypes. METHODS: We retrospectively examined 396 children with obesity (mean age 10.72 ± 2.71 years, body mass index-standard deviation score, BMI-SDS, 2.23 ± 0.57) stratified according to metabolic phenotypes. Kidney damage was defined as the presence of reduced estimated glomerular filtration rate (eGFR < 90 mL/min/1.73m2) and/or albuminuria (≥ 30 mg/g urinary creatinine). RESULTS: Kidney damage was found in 20.9% of the study population. Children with kidney damage had higher BMI-SDS, homeostasis model assessment of insulin resistance (HOMA-IR), and inflammation markers levels and increased prevalence of non-alcoholic fatty liver disease (NAFLD) than those without kidney damage (all p < 0.005). MUO and MHO subjects had respectively an odds ratio (OR) to show kidney damage of of 1.92 (95%CI:1.22-3.01; p = 0.005) and 1.05 (95%CI:1.00-1.09; p = 0.028) after adjustments. Moreover, we found that only HOMA-IR was closely associated to kidney damage in MUO group (OR = 2.07;95%CI:1.20-3.57; p = 0.007), while HOMA-IR (OR = 1.15;95%CI:1.02-1.29; p = 0.011) and uric acid (OR = 1.15;95% CI:1.02-1.30; p = 0.010) were the only significant risk factors for kidney damage in MHO group. CONCLUSION: An increased risk of kidney damage has been observed in children with obesity and in particular in those with MUO phenotype. As their role on kidney function, HOMA-IR should be monitored in MUO children and both HOMA-IR and uric acid in MHO children.

Obstructive sleep apnea (OSA) is associated with the impairment of beta-cell response to glucose in children and adolescents with obesity.

BACKGROUND: The main purpose of the study is to assess the association between obstructive sleep apnea (OSA) and insulin secretion in children with obesity. METHODS: We enrolled children and adolescents who attended our pediatric clinic because of obesity and OSA. Glucose homeostasis was assessed through standard 2-h oral glucose tolerance test (OGTT). Nocturnal cardio-respiratory polygraphy was performed for OSA diagnosis. Twenty-two patients underwent a 3-h OGTT to investigate insulin secretion and sensitivity through the oral-minimal model. RESULTS: seventy-seven children and adolescents were included in the study. Based on OSA severity, the cohort was divided into three groups (29 mild, 29 moderate, and 19 severe OSA). The group with mild OSA showed lower levels of 30-min glucose (p = 0.01) and 60-min glucose (p = 0.03), and lower prevalence of elevated 1-h glucose (10.4% versus 44.8% in moderate and 31.6% in severe OSA, p = 0.01). The odds for elevated 1-h plasma glucose was 6.2-fold (95%CI 1.6-23.4) higher in subjects with moderate and severe OSA compared to mild OSA (p = 0.007) independent of confounders. Spearman correlation test revealed a positive correlation between 30-min plasma glucose and apnea-hypopnea index (AHI, r = 0.31, p = 0.01), oxygen desaturation index (ODI, r = 0.31, p = 0.009), and mean desaturation (r = 0.25, p = 0.04). The 3-h OGTT study included 22 participants (7 mild, 9 moderate, and 6 severe OSA). The group with mild OSA showed a higher dynamic, static, and total insulin secretion compared to those with moderate and severe OSA (p < 0.0001, p = 0.007, p = 0.007, respectively). AHI was significantly correlated to dynamic insulin secretion (r = -0.48, p = 0.02). CONCLUSIONS: OSA might impair beta-cell function reducing the pool of promptly releasable insulin in children and adolescents with obesity, in the absence of an effect on insulin sensitivity.

Euthyroid sick syndrome and its association with complications of type 1 diabetes mellitus onset.

OBJECTIVE: To evaluate (i) the prevalence and association of euthyroid sick syndrome (ESS) [decreased FT3 and/or FT4 and normal/decreased TSH] with severity indexes of type 1 diabetes mellitus (T1DM) onset such as diabetic ketoacidosis (DKA) and kidney damage [acute kidney injury (AKI) based on KDIGO criteria, acute tubular necrosis (ATN), renal tubular damage (RTD)], (ii) relationship between clinical/metabolic parameters at T1DM onset and thyroid hormones, and (iii) ESS as a prognostic indicator of delayed recovery from kidney damage. METHODS: A total of 161 children with T1DM onset were included. RTD was defined by abnormal urinary beta-2-microglobulin and/or neutrophil gelatinase-associated lipocalin (NGAL) and/or tubular reabsorption of phosphate <85% and/or fractional excretion of Na>2%. ATN was defined by RTD+AKI. RESULTS: Of 161 participants, 60 (37.3%) presented ESS. It was more prevalent in case of more severe T1DM presentation both in terms of metabolic derangement (DKA) and kidney function impairment (AKI, RTD and ATN). Only ATN, however, was associated with ESS at adjusted analysis. FT3 inversely correlated with serum triglycerides and creatinine, and urinary calcium/creatinine ratio and NGAL. Participants with euthyroidism showed earlier recovery from AKI than those with ESS. ESS spontaneously disappeared. CONCLUSIONS: ESS is associated with T1DM onset severity and spontaneously disappears. ESS delayed the recovery from AKI. IMPACT: This is the first longitudinal study describing in detail the relationship between clinical/metabolic factors at type 1 diabetes mellitus (T1DM) onset and thyroid hormones, with particular attention to the relationship between diabetic ketoacidosis (DKA)-related kidney function impairment and euthyroid sick syndrome (ESS). Participants with more severe T1DM onset presentation both in terms of metabolic derangement and kidney function impairment had an increased prevalence of ESS. Children with ESS had a slower recovery from acute kidney injury compared with those without ESS. ESS spontaneously disappeared in all participants.

Acute and chronic kidney complications in children with type 1 diabetes mellitus.

Children with type 1 diabetes mellitus (T1DM) have an increased risk of developing kidney involvement. Part of the risk establishes at the beginning of T1DM. In fact, up to 65% of children during T1DM onset may experience an acute kidney injury (AKI) which predisposes to the development of a later chronic kidney disease (CKD). The other part of the risk establishes during the following course of T1DM and could be related to a poor glycemic control and the subsequent development of diabetic kidney disease. In this review, we discuss the acute and chronic effects of T1DM on the kidneys, and the implications of these events on the long-term prognosis of kidney function.

Body surface area-based kidney length percentiles misdiagnose small kidneys in children with overweight/obesity.

BACKGROUND: We evaluated the diagnostic performance of height-, age- and body surface area (BSA)-based kidney length (KL) percentiles in the identification of at least one small kidney (KL < 3rd) and in the prediction of reduced estimated glomerular filtration rate (eGFR) and/or elevated blood pressure (BP) in children with and without overweight (OW)/obesity(OB). METHODS: In this cross-sectional study, 744 apparently healthy children (mean age 8.3 years) were recruited in a primary care setting. Clinical data were collected, and serum creatinine and KL were measured. Height-, age- and BSA-based percentiles of KL were calculated and the association of at least one small kidney per subject with reduced eGFR and/or elevated BP was explored by logistic regression. RESULTS: Two hundred fifty-seven out of seven hundred forty-four (34.5%) subjects were OW/OB and 127 (17.1%) had reduced eGFR or elevated BP. In separate analyses in children with OW/OB, the KL percentiles calculated on the basis of BSA were lower compared with height- and age-based KL percentiles. Consequently, the prevalence of a small kidney was significantly higher when evaluating percentiles of KL based on BSA compared with other percentiles. In logistic regression analysis, a small kidney was significantly associated with reduced eGFR and/or elevated BP only when using height-based KL percentiles. The KL percentiles according to BSA for the ideal weight (iBSA) showed similar performance compared with height-based percentiles. No differences in the diagnostic performance of different percentiles were found in children with normal weight. CONCLUSIONS: BSA-based percentiles underestimate KL in children with OW/OB. In these subjects, the use of height-based or iBSA-based percentiles should be preferred. A higher resolution version of the Graphical abstract is available as Supplementary information.

Static cutoffs or tables for the diagnosis of hypertension? Effect on identification of organ damage in youths with obesity.

BACKGROUND AND AIM: Recently, the European Society of Cardiology task force released a Consensus document (ESC-CD) on pediatric hypertension (HTN) supporting the use of normative tables (age range 6-16 years) for the diagnosis of HTN, while the Hypertension Canada Guidelines (HTN-CGs) proposed static cutoffs. We aimed to assess the prevalence of HTN by ESC-CD or HTN-CGs and their association with glomerular function and left ventricular (LV) geometry in youths with overweight/obesity (OW/OB). METHODS AND RESULTS: Data of 3446 youths were analyzed. HTN by was defined using normative tables (ESC-CD) or static cutoffs of BP ≥ 120/80 in children (age <12 years) and ≥130/85 mmHg in adolescents (age ≥12 years) (HTN-CGs). Mildly reduced glomerular filtration rate was defined by GFR <90 ≥ 60 mL/min/1.73 m2. Concentric LV hypertrophy (cLVH) was assessed in 500 youths and defined by LVH and high relative wall thickness as proposed by ESC-CD. Prevalence of HTN was 27.9% by ESC-CD and 22.7% by HTN-CGs. The association with mildly reduced glomerular filtration rate was significant only in hypertensive adolescents classified by HTN-CGs [Odds Ratio (OR), 95%Cl] 2.16 (1.44-3.24), whereas the association with cLVH was significant using both criteria: children OR 2.18 (1.29-3.67) by ESC-CD and 2.27 (1.32-3.89) by HTN-CGs; adolescents OR 2.62 (1.17-5.84) by ESC-CD and 2.83 (1.14-7.02) by HTN-CGs. CONCLUSION: Although static cutoffs may represent a simplification for HTN identification, tables by ESC-CD detect a higher number of hypertensive youths before a clear appearance of glomerular impairment, which offers advantages in terms of primary cardiovascular prevention.

Uric acid could be a marker of cardiometabolic risk and disease severity in children with juvenile idiopathic arthritis.

In addition to disease-specific complications, juvenile idiopathic arthritis (JIA) has been linked to metabolic impairments in adults. Recent data supported the usefulness of uric acid (UA) as risk factor for cardiometabolic derangements. Given the lack of pediatric evidence in this field, we aimed to explore this association in a cohort of children diagnosed with JIA. We retrospectively evaluated 113 children diagnosed with JIA classified according to the International League of Association for Rheumatology (ILAR) criteria attending our Rheumatology Clinic. Both clinical and biochemical assessments were performed. Participants were stratified in four groups according to quartiles of serum UA. Disease activity was calculated by the Juvenile Arthritis Disease Activity Score 10 (JADAS-10) joint reduced count, and cut-offs for disease states were applied. Patients belonging to the highest UA quartile showed higher serum triglycerides, total cholesterol, creatinine, and glucose levels (p = 0.01, p = 0.025, p = 0.04, and p = 0.005, respectively) and lower HDL cholesterol values (p < 0.0001) than subjects belonging to the lowest quartiles. Ferritin, erythrocyte sedimentation rate levels, and age at disease onset did not significantly differ across UA quartiles (all p > 0.05). As activity disease index, JADAS-10 score significantly increased across UA quartiles (p = 0.009). CONCLUSION: Children with JIA presented with a worse cardiometabolic profile and a greater disease severity across UA quartiles. Our findings suggest that in clinical practice, UA might represent a useful marker of cardiometabolic risk and disease severity in children with JIA. WHAT IS KNOWN: • JIA has been linked to metabolic derangements in adulthood. • UA has been recognized as a marker of cardiometabolic risk both in adults and children. WHAT IS NEW: • Children with JIA belonging to the highest UA quartile showed a worse cardiometabolic profile and a greater disease severity. • UA might represent a helpful marker not only of cardiometabolic risk but also of disease severity in children with JIA.

Acute kidney injury in infants hospitalized for viral bronchiolitis.

We investigated prevalence of and factors associated with acute kidney injury (AKI) in a group of patients hospitalized with viral bronchiolitis. We retrospectively enrolled 139 children (mean age = 3.2 ± 2.1 months; males = 58.9%) hospitalized for viral bronchiolitis in a non-pediatric intensive care unit (PICU) setting. The Kidney Disease/Improving Global Outcomes creatinine criterion was used to diagnose AKI. We estimated basal serum creatinine by back-calculating it by Hoste (age) equation assuming that basal eGFR were the median age-based eGFR normative values. Univariate and multivariate logistic regression models were used to explore associations with AKI. Out of 139 patients, AKI was found in 15 (10.8%). AKI was found in 13 out of 74 (17.6%) patients with and in 2 out of 65 (3.1%) without respiratory syncytial virus (RSV) infection (p = 0.006). No patient required renal replacement therapies, while 1 out of 15 (6.7%) developed AKI stage 3, 1 (6.7%) developed AKI stage 2, and 13 (86.6%) developed AKI stage 1. Among the 15 patients with AKI, 13 (86.6%) reached the maximum AKI stage at admission, 1 (6.7%) at 48 h, and 1 (6.7%) at 96 h. At multivariate analysis, birth weight < 10th percentile (odds ratio, OR = 34.1; 95% confidence interval, CI = 3.6-329.4; p = 0.002), preterm birth (OR = 20.3; 95% CI = 3.1-129.5; p = 0.002), RSV infection (OR = 27.0; 95% CI = 2.6-279.9; p = 0.006), and hematocrit levels > 2 standard deviation score (SDS) (OR = 22.4; 95% CI = 2.8-183.6; p = 0.001) were significantly associated with AKI. CONCLUSION: About 11% of patients hospitalized with viral bronchiolitis in a non-PICU setting develop an AKI (frequently mild in degree). Preterm birth, birth weight < 10th percentile, hematocrit levels > 2SDS, and RSV infection are significantly associated with AKI in the setting of viral bronchiolitis. WHAT IS KNOWN: • Viral bronchiolitis affects children in the first months of life and in 7.5% of cases it can be complicated by acute kidney injury (AKI). • No studies investigated associations with AKI in infants hospitalized for viral bronchiolitis. WHAT IS NEW: • About 11% of patients hospitalized with viral bronchiolitis can develop an AKI (frequently mild in degree). • Preterm birth, birth weight <10th percentile, hematocrit levels > 2 standard deviation score, and respiratory syncytial virus infection are associated with AKI development in infants with viral bronchiolitis.

Combination therapy (desmopressin plus oxybutynin) improves the response rate compared with desmopressin alone in patients with monosymptomatic nocturnal enuresis and nocturnal polyuria and absence of constipation predict the response to this treatment.

Combination therapy (CT) (desmopressin plus oxybutynin) has been considered for the treatment of monosymptomatic nocturnal enuresis (MNE). We designed our study with the aim to evaluate the response rate to CT compared with desmopressin alone (primary outcome) and to identify factors associated with the response to CT (secondary outcome). We prospectively enrolled children with MNE with absent/partial response after 3 months of evening treatment with 240 mcg of desmopressin. We defined the response rate to CT compared with desmopressin alone according to the standardization of terminology document of the International Children's Continence Society: no-response, < 50% reduction; partial response, 50 to 99% reduction; and complete response, 100% reduction of wet nights. Both partial response and complete response to CT were clustered for the analyses of this manuscript. The enrolled children treated with 240 mcg/evening of desmopressin had also an additional evening administration of 0.3 mg/kg oxybutynin. A follow-up was scheduled at 3 and 6 months after the beginning of CT. At 3 months, oxybutynin dose was augmented to 0.5 mg/kg in case of absent/partial response to CT. Nocturnal diuresis was measured in 5 wet nights prior the beginning of therapy with desmopressin. Nocturnal polyuria (NP) was defined as nocturnal urine production > 130% of the expected bladder capacity. All patients with constipation were treated with macrogol. We enrolled 81 children (35.8% females) with a mean age of 8.4 ± 2.3 years. Seventy-eight patients completed the follow-up. After the CT, 59/78 (75.6%) patients showed an improvement of the response with CT compared with desmopressin alone. At multivariate analysis, both NP in more than 1 night (OR = 8.5; 95% CI, 1.4-51.6; p = 0.02) and absence of constipation (OR = 7.1; 95% CI, 1.6-31.0; p = 0.009) resulted significant after Bonferroni correction. CONCLUSIONS: CT determines an improvement of response compared to therapy with desmopressin alone in 75.6% of patients. Significant predictive factors of response to CT were presence of NP and absence of constipation. WHAT IS KNOWN: • Combination therapy (CT) (desmopressin plus anticholinergic drug) has been described as a therapeutic option for patients with monosymptomatic nocturnal enuresis (MNE) not responding to desmopressin alone as first-line treatment. • Variable protocols and variable combination of drugs have been described with a response rate ranging from 44 to 76%. WHAT IS NEW: • We found that 59 patients (75.6%) treated with evening administration of 240 mcg of sublingual desmopressin plus 0.3-0.5 mg/kg of oxybutynin had an improvement of response compared to treatment with desmopressin alone. • We add evidence that presence of frequently recurring nocturnal polyuria and absence of constipation are predictors of response to CT.

Uric acid versus metabolic syndrome as markers of fatty liver disease in young people with overweight/obesity.

AIMS: To compare the association of high serum uric acid (HUA) or metabolic syndrome (MetS) with fatty liver disease (FLD) in youths with overweight/obesity (OW/OB). MATERIALS AND METHODS: Cross-sectional study of anthropometrics, biochemical variables, and liver ultrasound of 3104 individuals with OW/OB (age 5-17 years). Metabolic syndrome was defined by ≥ 3 criteria among (1) high waist circumference; (2) high triglycerides; (3) low high-density lipoproteins; (4) fasting glucose ≥100 mg/dl; (5) blood pressure ≥95th percentile in children, and ≥130/80 mmHg in adolescents. High serum uric acid was defined as serum UA value ≥ 75th percentile adjusted for sex. Fatty liver disease was determined by echography. RESULTS: The sample was stratified in four categories: (1) no HUA, no MetS (reference category); (2) MetS; (3) HUA; (4) HUA and MetS (HUA + MetS). The prevalence of FLD increased across the four categories from 29.9%, 44.0%, 52.2%, to 67.1%, respectively (p < 0.0001). The ORs for the categorical variables were 1.33 (1.06-1.68) for MetS (p = 0.02), 3.19 (2.51-4.05) for HUA (p < 0.0001) and 3.72 (2.65-5.21) for HUA + MetS (p < 0.0001), versus the reference category regardless of the body mass index. CONCLUSIONS: HUA represents a useful marker of FLD in youths with OW/OB, given its greater ability to identify those at increased risk of the disease compared to MetS. The ability of both to predict incident FLD must be investigated in longitudinal study.

Evolution of congenital anomalies of urinary tract in children with and without solitary kidney.

BACKGROUND: We hypothesized that children with congenital solitary functioning kidney (CSFK) present forms of congenital urinary tract anomalies (CUTA) with higher chance of spontaneous resolution compared with patients with two kidneys. METHODS: We retrospectively selected 75 consecutive children with CUTA of the CSFK and 75 matched patients with unilateral CUTA but without CSFK (controls) with prenatal suspicion of unilateral CUTA and early evaluation. We compared the spontaneous CUTA resolution and the prevalence of kidney injury between groups at last follow-up. Patients and controls were clustered under the categories of "severe" and "non-severe" CUTA. RESULTS: The mean age at first and last follow-up was 0.17 ± 0.07 and 8.5 ± 5.2 years. Compared with controls, patients with CSFK had lower prevalence of severe CUTA at first evaluation; lower prevalence of febrile urinary tract infections, need of surgical correction, and higher rate of spontaneous CUTA resolution during follow-up; and a similar prevalence of mild kidney injury at last follow-up. CSFK compared with controls presented higher cumulative proportion of spontaneous resolution from severe CUTA (100 vs 41.8%; p < 0.001) and from the single CUTA sub-categories (severe vesicoureteral reflux, non-obstructive hydronephrosis, and megaureter). CONCLUSIONS: CSFK patients had lower prevalence of severe forms and better outcomes of their CUTA compared with controls. IMPACT: One-third of patients with congenital solitary functioning kidney (CSFK) present congenital urinary tract anomalies (CUTA) and manifest poorer outcomes compared with CSFK without CUTA. CSFK patients had lower prevalence of severe forms and better outcomes of their CUTA in spite of similar prevalence of kidney injury compared with controls. This adds evidence about disturbed nephrogenesis in CSFK patients and emboldens conservative management of many of their non-obstructive CUTA.

A new formula to improve the screening of impaired glucose tolerance in youths with overweight or obesity.

AIM: To assess a new formula to improve the screening of isolated impaired glucose tolerance (IGT) in youth with overweight/obesity (OW/OB). METHODS AND RESULTS: A cross-sectional study was performed in 1189 Caucasian youths with OW/OB aged 5-17 years, in whom impaired fasting glucose and high glycosylated hemoglobin were excluded. The sample was divided into training set (TS) (n = 883) and validation set (VS) (n = 306). Fasting (FG) and post-load plasma glucose, alanine aminotransferase (ALT), lipids and familial history for type 2 diabetes (FD) were available in all individuals. In the TS youths with IGT (n = 58, 7.0%) showed higher prevalence of female sex (FS), FD, and higher levels of FG, post-load glucose, ALT and lower levels of HDL-cholesterol vs individuals without IGT. The linear formula was obtained by logistic regression analysis in the TS: 0.05∗ALT + 0.07∗FG + 0.87∗FD + (0.06∗HDL∗ - 1) + 1∗FS. The best cut-off was 5.84. The performance of the formula vs IGT was: sensitivity: 0.74 and specificity: 0.71. Similar results were obtained in the VS. CONCLUSIONS: Using metabolic and anamnestic data we obtained a simple formula with a good performance for screening isolated IGT. This formula may support pediatricians to identify youths with OW/OB in whom the OGTT may be useful for detecting IGT.

Heart rate cut-offs to identify non-febrile children with dehydration and acute kidney injury.

We hypothesized that the heart rate (HR) variation in an acute setting compared with HR in wellbeing status could be a good marker of both dehydration and acute kidney injury (AKI). Since HR in wellbeing status is unknown in most cases, we assumed as reliable surrogate the 50th percentile of HR according to age and gender. We evaluated if the estimated percentage of heart rate variation in acute setting compared with 50th percentile of HR (EHRV) could be marker of dehydration and AKI in children. Two independent cohorts, one prospective comprehending 185 children at type 1 diabetes mellitus onset (derivation) and one retrospective comprehending 151 children with acute gastroenteritis and pneumonia (validation), were used to develop and externally validate EHRV as predictor of the ≥ 5% dehydration and/or AKI composite outcome. Febrile patients were excluded. EHRV was calculated as ((HR at admission-50th percentile of HR)/HR at admission) × 100. The prevalences of ≥ 5% dehydration and AKI were 61.1% and 43.8% in the derivation and 34.4% and 24.5% in the validation cohort. For the ≥ 5% dehydration and/or AKI composite outcome, the area under receiver-operating characteristic curve of the EHRV in the derivation cohort was 0.69 (95%CI, 0.62-0.77; p < 0.001) and the best EHRV cut-off was > 24.5%. In the validation cohort, EHRV > 24.5% showed specificity = 100% (95%CI, 96.2-100.0), positive predictive value = 100%, and negative predictive value = 67.1% (95%CI, 64.7-69.5). The positive likelihood ratio was infinity, and odds ratio was not calculable because all the patients with EHRV > 24.5% showed ≥ 5% dehydration and/or AKI.    Conclusions: EHRV appears a rather reliable marker of dehydration and AKI. Further validations could allow implementing EHRV in the clinical practice. What is Known: • Increased heart rate (HR) is an easily and quickly detectable sign of dehydration in childhood, but its cut-off to suspect dehydration or acute kidney injury (AKI) is not defined. What is New: • We found that a percentage of estimated HR variation in acute setting in comparison with 50th percentile of HR (EHRV)>24.5% predicted ≥5% dehydration and/or AKI in non-febrile patients. • We provide a one-page tool to suspect ≥5% dehydration and/or AKI on the basis of the HR. If furtherly validated, this tool could be implemented in the daily clinical practice.

PNPLA3 I148M Polymorphism Influences Renal Function in Children With Obesity and Prediabetes.

OBJECTIVE: Nonalcoholic fatty liver disease negatively impacts on renal function with the contribution of the I148 M variant in the patatin-like phospholipase-containing domain 3 (PNPLA3) gene. We hypothesized that children with prediabetes present with a lower estimated glomerular filtration rate (eGFR) than those with normal glucose tolerance (NGT) and that the 148M PNPLA3 allele could play a worsening role. We aimed evaluating the influence of the I148 M PNPLA3 polymorphism on the relationship between the eGFR and prediabetes in children with obesity. METHODS: One thousand thirty-six children underwent to complete assessment and were genotyped for the I148 M PNPLA3 polymorphism. RESULTS: Patients with prediabetes showed lower eGFR levels (171.03 ± 40.32 vs. 190.80 ± 41.71 mL/min/1.73 m2; P = .001) and higher prevalence of nonalcoholic fatty liver disease (80% vs. 59%; P = .003) than those with NGT. Children with prediabetes showed lower eGFR levels than those with NGT (150.97 ± 14.56 vs. 192.88 ± 40.09; P < .0001) among carriers of the PNPLA3 148M allele. This was not confirmed among patients homozygous for the PNPLA3 I148 allele. A general linear model for eGFR variance confirmed an inverse and significant association of the eGFR with prediabetes in patients carrying the 148M PNPLA3 allele but not in patients homozygous for the PNPLA3 I148 allele. CONCLUSIONS: Prediabetes negatively affects renal function in children with obesity. This effect is heightened in patients carrying the PNPLA3 148M allele.