Search

Summary Introduction Specific factors associated with the risk of developing pediatric urinary stone disease remain unclear, especially those that may be associated with recurrent stone disease. Objective We compared the results of 24-h urine collections in children with a solitary stone episode to those with multiple stone episodes to determine if there is a difference that may be associated with multiple stone formation in children. Study design A multi-institutional retrospective analysis was completed to assess 24-h urinary metabolic profiles in children with urolithiasis aged 2–18 years old. Differences in mean urine collections between the two groups were assessed using chi-square tests to test the associations among gender, stone type, and multiple stone status, as well as multivariate analyses using general linear models. Results We analyzed 142 solitary stone patients and 136 multiple stone patients from four centers were included. Multiple stone patients were older than solitary stone patients (mean 13.4 ± 3.6 years vs. 12 ± 3.9 years, p = 0.002). Females were more likely to have multiple stones (58% vs. 39%, p = 0.002). BMI was not associated with multiple stones ( p = 0.8467). Multiple stone formers had lower urine volumes, although this did not reach statistical significance when compared with solitary stone formation (20.4 mL/kg/day ± 11.5 vs. 22.9 ± 13.0, p = 0.0880). Higher values for super-saturation of calcium oxalate were associated with multiple stone disease in univariate ( p = 0.0485) and multivariate analysis ( p = 0.0469) (Figure). Centers located in the Southeast of the United States saw a higher proportion of children with multiple stones (Tennessee 62.7%, Virginia 44.4%, Oregon 31.6%, Michigan 27.3%, p < 0.0001). Discussion In a large multi-institutional retrospective analysis we found that multiple stone disease was associated with higher super-saturations of calcium oxalate. Many urinary parameters changed with patient age, highlighting that the values should be interpreted with respect to patient age. The inability to comment on follow-up because of the nature of our dataset is a limitation of this study. Conclusion Multiple stone disease in children is associated with higher super-saturation calcium oxalate, while lower urinary volume may also be associated with multiple stones; however, further study is required. Early metabolic evaluation may help risk stratify children likely to form multiple stones. Figure Super-saturation of calcium oxalate and multiple stone status. [ABSTRACT FROM AUTHOR]

Obesity is rampant across the spectrum of age, gender, and race in the Unites States. Paralleling this epidemic, kidney stone prevalence is also rising, affecting nearly 1 in 11 individuals. Bariatric surgical procedures, such as Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), are the most effective weight loss options for morbidly obese or severely obese individuals with comorbidities. A number of studies have linked kidney stone development to bariatric surgical history, particularly RYGB, which portends up to a threefold increase in calcium oxalate stone risk compared with age-matched, obese controls. Stone development after malabsorptive (RYGB) and restrictive (SG) bariatric procedures are driven primarily by alterations in 24-h urine profiles, such as increased urinary oxalate, decreased urine volume, and reduced urinary citrate levels-all of which have been linked to increased kidney stone risk. What clinical recommendations, if any, can be given to reduce kidney stone risk in bariatric kidney stone patients? This review provides not only updated stone incidence and 24-h urine data in this population, but also reassurance-the metabolic alterations that result from bariatric surgery can be successfully mitigated by increased provider awareness, patient education, and a combination of dietary and pharmacological adjustments., Competing Interests: No competing financial interests exist.

Summary Objective In recent years, there has been increased incidence of urolithiasis in children. Changing nutritional patterns and sedentary lifestyles predispose to urolithiasis, as well as to the global rise in obesity. It has been established that the prevalence of high body mass index (BMI) is increasing in the pediatric population. The aim of the present study was to incorporate 24-h urine metabolic analysis results with BMI values to evaluate the tendency towards stone formation in children. Methods Eighty-four children were recruited to the study, stratified into three BMI categories as low, normal, or upper. All patients were evaluated with 24-h urine analysis results. Patients with a secondary cause of stone formation such as hyperparathyroidism, cystinuria, primary hyperoxaluria, inflammatory bowel disease, cystic fibrosis, history of prematurity and/or use of drug, recurrent urinary tract infection, and urinary tract anomaly were excluded. Additionally, it was ensured that none of the patients were taking specific medication or diet that could alter their acid-base metabolism and calcium, oxalate, and uric acid levels. Results Mean BMI of patients was 21.6 ± 2.9 kg/m 2 . LBMI was found in 52 (61.9%), N-BMI in 20 (23.8%), and U-BMI in 12 (14.3%) of the patients. No significant differences were present between the three groups for stone sizes and numbers. The patients' characteristics and 24-h urine parameters for BMI groups are presented in the Table. Discussion In the literature, several studies have focused on the relationship between obesity and pediatric urinary stone disease. However, only a few evaluated the urinary metabolic analysis in pediatric patients. We have encountered different results from mainly adult studies and some pediatric studies. Our study shows that U-BMI children are not under greater risk for urolithiasis than the other groups. An important portion of our study group was in the L-BMI group; nevertheless we cannot conclude that having a low BMI predisposes to urolithiasis based on the urinary metabolic evaluation as well as the stone sizes and numbers. The N-BMI group has increased risk factors for urolithiasis rather than the other groups, according to results of 24-h urine analysis. Conclusion The results of our study indicate that BMI itself could not be considered as a separate and definite risk factor for urolithiasis development in children. Although the mechanisms and causative factors for urinary stone formation are better defined in adults, further studies investigating these parameters in children are warranted. Table Patients' characteristics and 24-h urine parameters for BMI groups. L-BMI mean ± SD N-BMI mean ± SD U-BMI mean ± SD p Sex Male 28 8 6 0.575 Female 24 12 6 Age (years) 6.9 ± 4.0 9.2 ± 4.5 9.4 ± 5.5 0.071 BMI (kg/m 2 ) 15.5 ± 1.6 20.8 ± 1.5 30.1 ± 2.9 <0.001 Stone number 1.6 ± 1.0 2.0 ± 1.5 1.7 ± 0.8 0.709 Stone size (mm) 13.7 ± 10.2 13.8 ± 10.5 13.0 ± 9.6 0.951 Ca (mg/kg/24 h) 3.7 ± 3.0 4.2 ± 3.9 1.3 ± 0.9 0.021 Citrate (mg/1.73 m 2 /24 h) 362 ± 442 461 ± 391 622 ± 450 0.057 Uric acid (mg/kg/24 h) 4.6 ± 4.0 3.2 ± 2.7 1.8 ± 1.4 0.017 a Oxalate (mg/1.73 m 2 /24 h) 7.4 ± 10.6 12.0 ± 12.4 9.9 ± 6.2 0.003 Magnesium (mg/kg/24 h) 4.0 ± 3.3 3.3 ± 2.1 3.2 ± 2.2 0.609 Sodium (mmol/24 h) 91.3 ± 46.9 108.2 ± 76.1 88.3 ± 45.9 0.897 a Difference between L-BMI and U-BMI groups. [ABSTRACT FROM AUTHOR]

Objective: Iodine deficiency has severe pathological repercussions. The aim of this study was to evaluate iodine intake and status in adults in Benin, West Africa., Methods: We randomly selected 420 participants ages 25 to 64 y and free of visible goiter from urban and rural settings of South Benin. The participants had a diet based on carbohydrates and fish. Urine was collected over a 24-h period and samples were assayed for iodine analysis using inductively coupled plasma mass spectrometry., Results: We studied 401 urinary iodine samples. The overall median urinary iodine concentration (UIC) in 24-h urine was 62.9 μg/L (interquartile range: 40-96.2 μg/L). UIC was significantly lower in women than men (56.5 versus 78.6 μg/L; P < 0.001) and in rural versus urban areas (54.7 versus 77.8 μg/L; P < 0.001). In multivariate analysis, low UIC (<100 μg/L) was positively associated with women (odds ratio, 2.48; 95% confidence interval, 1.44-4.26; P = 0.001) and body mass index <25 kg/m(2) (odds ratio, 2.06; 95% confidence interval, 1.20-3.54; P = 0.008)., Conclusion: Iodine intake appeared to be fairly low in the Beninese population, according to World Health Organization criteria, and factors associated with low iodine intake were identified. Public health interventions to increase iodine intake, such as iodization of commercial salt and/or fortification of selected nutrients, should be strengthened at the national level., (Copyright © 2016 Elsevier Inc. All rights reserved.)