Eleonora Moreira Lima

Bone alterations in children with idiopathic hypercalciuria at the time of diagnosis

Abstract.Some children with idiopathic hypercalciuria (IH) develop bone alterations at some stage of the disease. The aims of this study were to evaluate bone mass in 88 children with IH (G1) at the time of diagnosis and to compare the findings with data for a control group of 29 normal children (G2). Kidney and bone metabolism markers were measured in both groups, and bone densitometry was performed. Serum alkaline phosphatase, intact parathyroid hormone, urinary calcium and uric acid were significantly higher in G1, whereas urinary volume and urinary citrate excretion were lower. The following densitometric parameters were significantly lower in G1: (1) lumbar spine (L2-L4) bone mineral density (BMD), bone mineral content (BMC), BMC corrected for height and for width of the vertebra, volumetric BMD (BMDvol), and Z score; (2) whole-body BMD; (3) femoral neck BMD. Lumbar spine BMDvol was reduced (osteopenia) in 35% of the patients compared with G2. N telopeptide, a urinary marker of bone resorption, was significantly higher in G1 than in G2, and was negatively correlated with lumbar spine BMD and BMDvol. Children with urinary lithiasis or idiopathic hyperuricosuria associated with IH showed no significant differences in bone metabolism compared with children without these associations. We conclude that (1) there is an altered bone metabolism in IH, with osteopenia already present at diagnosis in 35% of the patients; (2) N telopeptide is one of the most useful markers of bone alterations in IH, especially at an early stage of the disease; (3) investigation of bone metabolism is necessary in IH to prevent future serious consequences such as osteoporosis and bone fractures.

Risk factors for renal scarring in children and adolescents with lower urinary tract dysfunction

AbstractRisk factors for renal scarring in children with lower urinary tract dysfunction (LUTD) were evaluated. The medical records of 120 patients were assessed concerning gender, presence of vesicoureteric reflux (VUR), bladder capacity, detrusor overactivity, residual urine, febrile urinary tract infection (UTI), bacteriuria, constipation, detrusor sphincter incoordination (DSI), high detrusor pressure at maximal cystometric capacity (PMCC), low compliance, and thickness and trabeculation of the bladder wall. Renal scarring was diagnosed by 99mtechnetium-dimercaptosuccinic acid renal scan (DMSA). Renal scarring was detected in 38 patients (31%). VUR, UTI, decreased bladder capacity, urinary residue, and trabeculated and thick bladder wall were associated with scarring at univariate analysis. Multivariate analysis showed VUR (P < 0.0001) as the independent risk factor for renal scarring. Thickness of the bladder wall was a marginal risk factor (P  = 0.07). Although UTI was not a risk factor, it was associated with VUR (P  = 0.03). In our analysis, VUR was the main risk factor; however, renal scarring was probably due to multifactorial causes, as VUR was associated with UTI.

Voiding dysfunction in children. Pelvic-floor exercises or biofeedback therapy: a randomized study

Fifty-six patients 5.9–15.2 years old with dysfunctional elimination syndrome (DES) unimproved by previous therapies were randomly distributed into two voiding training programs: group 1 contained 26 patients submitted to 24 training sessions over a 3-month period; group 2 contained 30 patients submitted to 16 sessions over a 2-month period. Both groups adhered to a voiding and drinking schedule, received instruction on adequate toilet posture, were reinforced through the maintenance of voiding diaries, and went through proprioceptive and pelvic floor muscle training (Kegel exercises). Group 2 patients also received biofeedback therapy. Clinical evaluation was carried out before each program’s initiation and 1, 6, and 12 months after each program’s termination. All patients were submitted to renal ultrasonography and dynamic ultrasonography before and 6 months after each program’s conclusion. Millivoltage recordings of pelvic floor muscles were compared before and after training. Urinary continence was improved after completion of either training program. Only those patients who received biofeedback training showed a significant decrease in postvoiding residual (PVR) urine as detected by dynamic ultrasonography. Our results show that either training regime can reduce episodic urinary incontinence and urinary tract infection but that further study is required to identify the optimal training duration.

Prevalence of lower urinary tract symptoms in school-age children.

Epidemiological studies have demonstrated rates of incontinence and enuresis as high as 20% in school-age children. This cross-sectional study aimed to investigate the prevalence of lower urinary tract (LUT) symptoms in 739 children aged 6–12 years enrolled in three government schools with different socioeconomic levels in Minas Gerais, Brazil. Symptoms of LUT were evaluated using a modified version of the Dysfunction Voiding Scoring System in which the cutoff point considered as an indicator of LUT dysfunction is >6 for girls and >9 for boys. Children with a score indicative of symptoms received an educational booklet on the functioning of the LUT and were sent for clinical evaluation. LUT dysfunction symptoms were detected in 161 (21.8%) children. Symptoms were most frequent in girls (p < 0.001), children aged 6–8 (p < 0.028), and attended the school with the lowest social level (p < 0.001). Intestinal constipation was the most prevalent finding (30.7%), independent of LUT score. The most common urinary symptoms in children with an elevated score were diurnal urinary incontinence (30.7%), holding maneuvers (19.1%), and urinary urgency (13.7%). Stress factors were associated in 28.4% of children. Our findings suggest that LUT symptoms must be investigated carefully at routine pediatric visits.

Risk factors for recurrent urinary tract infections in a cohort of patients with primary vesicoureteral reflux.

Background: Knowledge of risk of urinary tract infection (UTI) recurrence in vesicoureteral reflux (VUR) can help clinicians make therapeutic decisions. The aim of this retrospective cohort study was to identify risk factors associated with recurrent urinary tract infection in children with VUR. In addition, a risk score that might predict the chance of UTI recurrence was also proposed. Methods: Between 1970 and 2007, 740 patients were diagnosed with VUR and were systematically followed up at a single tertiary Renal Unit. Recurrent UTI was defined as more than 1 episode during follow-up. A binary logistic regression model was applied to identify variables independently associated with recurrent UTIs. Results: During follow-up, information was obtained on 58,856 person-months. Recurrent UTIs occurred in 120 (16.2%) patients. The overall incidence rate of UTI was 8.4 episodes per 1000 person-months (95% CI, 7.7, 9.2). After adjustment by multivariable analysis, 5 variables were independent predictors of recurrent UTI: UTI as clinical presentation, age <6 months, female gender, dysfunctional elimination syndrome, and severe grade of reflux. The risk for recurrent UTI was classified as low in 24% of children, medium in 42%, and high in 34%. UTI incidence rates per 1000 person-months were 4.3 (95% CI, 3.2, 5.6), 7.9 (95% CI, 6.7, 9.1), and 11.3 (95% CI, 9.9, 12.8) for low-, medium-, and high-risk groups, respectively. Conclusion: The prediction model of recurrent UTI allows an early recognition of patients at risk for long-term morbidity and might contribute to the formulation of therapeutic strategies.

Assessment of risk factors associated with elevated blood pressure in children and adolescents

Hypertension in children is associated with a higher incidence of secondary causes than in adults; however, in the last decade, studies have shown an increase in the incidence of essential hypertension in the pediatric population, especially among adolescents. The most important etiologic factor for essential hypertension in children is obesity, which has become an epidemic problem.1,2 Other implicated factors include insulin resistance, changes in the glucose and lipid metabolism, and reduced arterial compliance. 3

Predictive factors of progression to chronic kidney disease stage 5 in a predialysis interdisciplinary programme

BACKGROUND The clinical course of chronic kidney disease (CKD) in children is heterogeneous and has not been fully established. The aim of this retrospective cohort study was to identify predictive factors associated with the progression of CKD among the children and adolescents admitted to a Predialysis Interdisciplinary Management Programme (PDIMP). METHODS We analysed the following variables at admission: age, gender, race, blood pressure, primary renal disease, Z-scores for weight and height, CKD stage and degree of proteinuria. Two time-dependent covariates were considered: hypertension and proteinuria. CKD stage 5 was assigned as a dependent variable. Time-fixed and time-dependent Cox regression analyses were applied to evaluate renal survival. RESULTS One hundred and seven patients with CKD stage 2-4 were followed up for a median time of 94 months. Fifty-seven patients (53.3%) progressed to CKD stage 5. After adjustment for time-fixed model, three baseline variables were found to be independent predictors of CKD stage 5: glomerular disease (hazard ratio, HR = 3.0, P = 0.015), CKD stage 4 (HR = 2.6, P = 0.001) and severe proteinuria (HR = 4.1, P = 0.006). After adjustment for the time-dependent model, three variables were found to be independent predictors of CKD stage 5: proteinuria as time-dependent covariate (HR = 1.9, P = 0.041), CKD stage 4 (HR = 2, P = 0.0086) and baseline serum albumin <3.5 g/dl (HR = 2.6, P = 0.0015). CONCLUSIONS Taking into account manageable factors, further prospective controlled studies are necessary to assess intervention measures in order to possibly modify the clinical course of CKD in children.

Combined Use of Late Phase Dimercapto-Succinic Acid Renal Scintigraphy and Ultrasound as First Line Screening After Urinary Tract Infection in Children

PURPOSE The aim of this study was to evaluate the diagnostic accuracy of dimercapto-succinic acid renal scintigraphy and renal ultrasound in identifying high grade vesicoureteral reflux in children after a first episode of urinary tract infection. MATERIALS AND METHODS A total of 533 children following a first urinary tract infection were included in the analysis. Patients were assessed by 3 diagnostic imaging studies, renal ultrasound, dimercapto-succinic acid scan and voiding cystourethrography. The main event of interest was the presence of high grade (III to V) vesicoureteral reflux. The combined and separate diagnostic accuracy of screening methods was assessed by calculation of diagnostic OR, sensitivity, specificity, positive predictive value, negative predictive value and likelihood ratio. RESULTS A total of 246 patients had reflux, of whom 144 (27%) had high grade (III to V) disease. Sensitivity, negative predictive value and diagnostic OR of ultrasound for high grade reflux were 83.3%, 90.8% and 7.9, respectively. Dimercapto-succinic acid scan had the same sensitivity as ultrasound but a higher negative predictive value (91.7%) and diagnostic OR (10.9). If both tests were analyzed in parallel by using the OR rule, ie a negative diagnosis was established only when both test results were normal, sensitivity increased to 97%, negative predictive value to 97% and diagnostic OR to 25.3. Only 9 children (6.3%) with dilating reflux had an absence of alterations in both tests. CONCLUSIONS Our findings support the idea that ultrasound and dimercapto-succinic acid scan used in combination are reliable predictors of dilating vesicoureteral reflux.

Independent risk factors for renal damage in a series of primary vesicoureteral reflux: A multivariate analysis

Aim:  The aim of this study was to investigate risk factors associated with different extents of renal parenchyma involvement in a paediatric series of primary vesicoureteral reflux (VUR).

Avaliação do acesso vascular para hemodiálise em crianças e adolescentes: um estudo de coorte retrospectivo de 10 anos

INTRODUCTION The complications of vascular access have been the major cause of hospitalization among patients with end stage renal disease (ESRD) on Haemodialysis (HD). Despite recommendations to decrease the use of central venous catheter (CVC) it still represents the main access for children and adolescents who start HD. OBJECTIVES AND METHODS This study aimed to evaluate, through a retrospective cohort study, the initial type, the incidence of complications and reasons for failure of vascular access in children and adolescents aged 0 to younger than 18 years who started HD from 1997 to 2007. RESULTS 251 accesses were studied in 61 patients, 97 arteriovenous fistula (AVF) and 154 temporary uncuffed CVC. 51% of study patients began HD with CVC. The mean age of patients at the start of HD was 12.5 years. The predominant underlying disease was glomerulonephritis (46%). The main cause of CVC removal was infection in 35%. The mean survival of the uncuffed CVC was 40 days. AVF primary failure was detected in 37.8% of the fistulas. Considering the patent fistulas, the main cause of failure was thrombosis (84%). Infection did not caused any loss of AVF. When comparing the two types of access we find a risk of infection 34 times higher in patients using CVC against AVF. CONCLUSION Infection was the major cause of CVC removal, and our results suggest that uncuffed CVC must be avoided for ESRD children and adolescents on HD and replaced by AVF or cuffed CVC, whenever it is feasible. Thrombosis was the main cause of AVF loss, urging the need of implementation of a program for early detection of access failure.