Nutritional aspect of nephrolithiasis

Ureterolithiasis in Adolescents: A Case Report

A 13-year-old patient presented to the emergency department with a history of abdominal pain and right flank pain. Two days before, she was evaluated at her pediatrician's office and was diagnosed with acute gastroenteritis and sent home. In the emergency department, the patient was diagnosed with ureterolithiasis after a physical examination, laboratory work, and imaging findings. She was treated successfully with conservative medical management. Symptomatic presentation of ureterolithiasis can include abdominal pain, flank pain, hematuria, dysuria, urgency, nausea, and vomiting. Nurse practitioners need to recognize nonspecific symptoms of ureterolithiasis for accurate diagnosis and treatment. Risk factors, signs and symptoms, prevention, and treatment options for ureterolithiasis are discussed.

Metabolic risk factors and the role of prophylaxis in pediatric urolithiasis

Suppose that the recurrence in pediatric urolithiasis has a close relationship with metabolic abnormalities and is affected by residual burden and prophylaxis. If so, the recurrence rates could be reduced with effective surgery and appropriate prophylaxis. Here we retrospectively evaluate the metabolic risk factors data of 148 children who were operated on between January 2005 and March 2013 due to kidney stones. All patients underwent percutaneous nephrolithotomy (PCNL), and all were children. Thirteen children had a history of surgery performed to treat urological anomalies. Twenty-four-hour urine analysis, the residual status of surgery, BMI levels, and the number of metabolic abnormalities were noted. Only 18 (15%) of 122 patients without residual stones after PCNL had recurrence at follow-up whereas; nine (26%) of 26 patients with residual stones developed recurrence (p = 0.017). Recurrence was observed in 14 (16%) of 89 patients with a metabolic abnormality, and 13 (30%) of 44 patients with two or more metabolic abnormalities had recurrence at follow-up (p = 0.024). Those patients with no metabolic abnormalities did not develop recurrence. Stone recurrence was seen in six (8%) of 78 children who were given metabolic prophylaxis, compared to 21 (30%) of 70 patients who did not receive metabolic prophylaxis (p = 0.02). No stone recurrence was seen in nine children who were given Shohl's, whereas four (67%) of six patients who did not take Shohl's had recurrence (p = 0.022). Complete removal of stones by a suitable surgical method is essential to avoid recurrences. Detailed clinical and laboratory evaluations should be performed in children with urolithiasis. Appropriate specific prophylactic treatment (e.g., potassium citrate and Shohl's) and non-specific prophylactic treatment (e.g., avoiding animal proteins, salt, simple sugars, and increased water intake) should be given to prevent reformation of stones in patients with pediatric urolithiasis.

Identification of Novel Human Serum Albumin (SA) Inhibitors from Scoparia Dulsis for Urolithiasis

Background::

Urolithiasis is the process of forming stones in the kidney, bladder, and/or urinary tract. It has been reported that kidney stones are the third most common disorder among urinary diseases. At present, surgical procedures and Extracorporeal Shock Wave Lithotripsy (ESWL) are commonly employed for the treatment of Urolithiasis. The major drawback of these procedures is the recurrence of stones.

Methods:

This study aimed to identify potential natural inhibitors against human Serum Albumin (SA) from the plant Scoparia Dulsis for Urolithiasis. As protein-ligand interactions play a key role in structure- based drug design, this study screened 26 compounds from Scoparia Dulsis and investigated their binding affinity against SA by using molecular docking. The three dimensional (3D) structure of SA was retrieved from Protein Data Bank (PDB) and docked with PubChem structures of 26 compounds using PyRX docking tool through Autodock Vina. Moreover, a 3D similarity search on the PubChem database was performed to find the analogs of best scored compound and docking studies were performed. Drug-likeness studies were made using Swiss ADME and Lipinski’s rule of five was performed for the compounds to evaluate their anti-urolithiatic activity.

Results:

The results showed that citrusin c (Eugenyl beta-D-glucopyranoside) exhibited best binding energy of -8.1 kcal/mol with SA followed by aphidicolin, apigenin, luteolin and scutellarein. Two compounds (PubChem CID 46186820, PubChem CID 21579141) analogous to citrusin c were selected based on the lowest binding energy.

Conclusion:

This study, therefore, reveals that these compounds could be promising candidates for further evaluation for Urolithiasis prevention or management.

Update on cystine stones: current and future concepts in treatment

Cystine stones are relatively uncommon compared with other stone compositions, constituting just 1% to 2% of adult urinary tract stone diseases, and accounting for up to 10% of pediatric stone diseases. Two responsible genes of cystinuria have been identified, the SLC3A1 and the SLC7A9. Cystinuria is diagnosed by family history, stone analysis, or by measurement of urine cystine excretion. Current treatments for cystinuria include increased fluid intake to increase cystine solubility by maintaining daily urine volume of greater than 3 Liter (L). Limiting sodium and protein intake can decrease cystine excretion. When conservative therapy fails, then pharmacologic therapy may be effective. Alkaline urine pH in the 7.0-7.5 range will reduce cystine solubility and can be achieved by the addition of alkali therapy. If these measures fail, cystine-binding thiol drugs such as tiopronin and D-penicillamine are considered. These compounds bind cysteine and prevent the formation of less soluble cystine. These drugs, however, have poor patient compliance due to adverse effects. Captopril can be useful in the treatment of cystine stones but the drug has not been tested in rigorous clinical trials. Novel potential therapies such as alpha-lipoic acid and crystal growth inhibitors (L-cystine dimethyl ester (L-CDME) and L-cystine methyl ester (L-CME)) were developed and tested in animals. Those therapies showed promising results. Compliance with treatment was associated with a lower rate of cystine stone formation.

XANTHINE NEPHROLITHIASIS IN JUVENILE CAPTIVE GIANT OTTERS (PTERONURA BRASILIENSIS)

Nephrolithiasis has been reported in several aquatic mammals including bottlenose dolphins (Tursiops truncatus), small clawed otters (Amblonyx cinereus), European river otters (Lutra lutra), North American river otters (Lontra canadensis), northern elephant seals (Mirounga angustirostris), Florida manatees (Trichechus manatus latirostris), and California sea lions (Zalophus californianus). Compositions of calculi in previous cases were predominantly calcium oxalate or ammonium acid urate. Xanthine urolithiasis is rare in veterinary medicine. Primary cases (without exposure to xanthine dehydrogenase inhibitors) occur as a consequence of hereditary xanthinuria, although the causal mutation has only been discovered in a subset of cases. Five captive juvenile giant otters (Pteronura brasiliensis) from two facilities were diagnosed with nephrolithiasis: three siblings from one set of parents and two siblings from another pair. Serum analyte assays revealed renal compromise in affected individuals. Computed tomography (CT) confirmed the presence of nephrolithiasis in one individual. Postmortem evaluation identified extensive bilateral nephrolithiasis on gross necropsy in four of five cases. Calculus analyses identified 100% xanthine composition. Histologic examination revealed marked nephrolithiasis with associated tubular necrosis and gastric mineralization. Nutrient composition of the diet including mineral and purine content was assessed. No association between diet and nephroliths was found in this study. This is the first report of xanthine nephrolithiasis in aquatic mammals. The potential role of diet and genetics in xanthine nephrolithiasis in the small inbred population of giant otters under human care needs further investigation to assess the implications of this disease process for the long-term captive management of this species.

Diet and stone formation: a brief review of the literature

PURPOSE OF REVIEW

Urolithiasis is a very common condition, which can be accompanied by serious complications. Diagnosis, treatment, and prevention are of great cost for national health systems. Many studies have been published about the role of diet in both stone formation and prevention. The aim of this review is to summarize the most recent developments that correlate diet to lithiasis.

RECENT FINDINGS

Recurrent stone formers should undergo metabolic evaluation and stone chemical analysis. Current evidence propose difference approaches based on the metabolic disorder that is diagnosed. Diet could have a detrimental role in the prevention of recurrences. Prevention advises include increased fluid uptake, vegetables and fruit intake but decreased sugar, salt, and meat consumption.

SUMMARY

The analysis of the food contents and their role to lithogenesis prevention are of great importance. Modifying diet to prevent stones could help many people who suffer from lithiasis to avoid recurrence and the consequences. Furthermore, the cost for diagnosis and treatment could be significantly reduced. Therefore, the field of dietary factors in lithogenesis should be further investigated.

Medical and dietary interventions for preventing recurrent urinary stones in children

BACKGROUND

Nephrolithiasis, or urinary stone disease, in children causes significant morbidity, and is increasing in prevalence in the North American population. Therefore, medical and dietary interventions (MDI) for recurrent urinary stones in children are poised to gain increasing importance in the clinical armamentarium.

OBJECTIVES

To assess the effects of medical and dietary interventions (MDI) for the prevention of idiopathic urinary stones in children aged from one to 18 years.

SEARCH METHODS

We searched multiple databases using search terms relevant to this review, including studies identified from the Cochrane Central Register of Controlled Trials (CENTRAL, 2017, Issue 1), MEDLINE OvidSP (1946 to 14 February 2017), Embase OvidSP (1980 to 14 February 2017), International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. Additionally, we handsearched renal-related journals and the proceedings of major renal conferences, and reviewed weekly current awareness alerts for selected renal journals. The date of the last search was 14 February 2017. There were no language restrictions.

SELECTION CRITERIA

Randomized controlled trials of at least one year of MDI versus control for prevention of recurrent idiopathic (non-syndromic) nephrolithiasis in children.

DATA COLLECTION AND ANALYSIS

We used standard methodologic procedures expected by Cochrane. Titles and abstracts were identified by search criteria and then screened for relevance, and then data extraction and risk of bias assessment were carried out. We assessed the quality of evidence using GRADE.

MAIN RESULTS

The search identified one study of 125 children (72 boys and 53 girls) with calcium-containing idiopathic nephrolithiasis and normal renal morphology following initial treatment with shockwave lithotripsy (SWL). Patients were randomized to oral potassium citrate 1 mEq/kg per day for 12 months versus no specific medication or preventive measure with results reported for a total of 96 patients (48 per group). This included children who were stone-free (n = 52) or had residual stone fragments (n = 44) following SWL. Primary outcomes:Medical therapy may lower rates of stone recurrence with a risk ratio (RR) of 0.19 (95% confidence interval (CI) 0.06 to 0.60; low quality evidence). This corresponds to 270 fewer stone recurrences per 1000 (133 fewer to 313 fewer) children. We downgraded the quality of evidence by two levels for very serious study limitations related to unclear allocation concealment (selection bias) and a high risk of performance, detection and attrition bias. While the data for adverse events were incomplete, they reported that six of 48 (12.5%) children receiving potassium citrate left the trial because of adverse effects. This corresponds to a RR of 13.0 (95% CI 0.75 to 224.53; very low quality evidence); an absolute effect size estimate could not be generated. We downgraded the quality of evidence for study limitations and imprecision.We found no information on retreatment rates.

SECONDARY OUTCOMES

We found no evidence on serum electrolytes, 24-hour urine collection parameters or time to new stone formation.We were unable to perform any preplanned secondary analyses.

AUTHORS' CONCLUSIONS

Oral potassium citrate supplementation may reduce recurrent calcium urinary stone formation in children following SWL; however, our confidence in this finding is limited. A substantial number of children stopped the medication due to adverse events. There is no trial evidence on retreatment rates. There is a critical need for additional well-designed trials in children with nephrolithiasis.

The role of sodium intake in nephrolithiasis: epidemiology, pathogenesis, and future directions

The prevalence of nephrolithiasis has doubled over the last decade and the incidence in females now approaches that of males. Since dietary salt is lithogenic, a purported mechanism common to both genders is excess dietary sodium intake vis-a-vis processed and fast foods. Nephrolithiasis has far-reaching societal implications such as impact on gross domestic product due to days lost from work (stone disease commonly affects working adults), population-wide carcinogenic diagnostic and interventional radiation exposure (kidney stone disease is typically imaged with computed tomographic imaging and treated under imaging guidance and follow-up), and rising healthcare costs (surgical treatment will be indicated for a number of these patients). Therefore, primary prevention of kidney stone disease via dietary intervention is a low-cost public health initiative with massive societal implications. This primer aims to establish baseline epidemiologic and pathophysiologic principles to guide clinicians in sodium-directed primary prevention of kidney stone disease.

Percutaneous endoscopic treatment for urinary stones in pediatric patients: where we are now

BACKGROUND

Percutaneous nephrolithotomy (PCNL) has been adopted for pyelo-calyceal stones treatment in pediatric patients, starting from the 90's. Very recently, miniaturization of endoscopic instruments allowed less invasive procedures with low complication rate. We reviewed our experience on upper tract stone treatment utilizing two different percutaneous accesses, focusing on the recent new miniaturized devices offered for pediatric renal stones.

METHODS

Patients presenting upper tract urinary stones observed from January 2011 to December 2015 and treated by percutaneous renal access were prospectively evaluated: age, sex, metabolic issues, associated abnormalities, treatment modalities, hospital stay and complication rate were recorded in a specific database. Two different endourological percutaneous modalities were adopted, depending to the stone size and position. PCNL was performed through a direct calyceal puncture under ultrasonographic and fluoroscopic guidance and Amplatz access dilatation till 24 Fr. Ballistic energy was used for fragmentation. Micropercutaneous (Microperc) procedure was recently offered utilizing a 4.85 Fr metallic needle and Holmium:YAG laser lithotripsy under direct vision through a 0.9 mm high resolution optic flexible wire connected with a telescope.

RESULTS

Thirty-eight percutaneous access to pyelo-calyceal renal stones were performed on a total of 108 children treated for upper tract stones, aged 4 to 18 years (mean age 7.5 years). The overall number of procedures was 144 (36 repeated procedures). Cystinuria was diagnosed in 5 patients. PCNL was adopted in 28 patients, Microperc was utilized in 8 patients. Hemoglobin dropdown was limited to 1.20±0.80 mg% in PCNL and was not significant in Microperc. No blood transfusion was needed. No significant complications were observed. Stone free rate or minimal not significant residuals were achieved in 82% of PCNL and in 87.5% of Microperc, after a single procedure.

CONCLUSIONS

Percutaneous endoscopic treatment of renal calculi is feasible in pediatric age, with high success rate in a single step. Advanced miniaturized endoscopic devices as Microperc guarantee high efficacy and reduced complication rate, but endo-urological experience and adequate learning curve are required, especially in small body weight children. Centralization of these patients in Pediatric Stone Centers is welcomed to optimize results and reduce risks.

Percutaneous Nephrolithotomy vs Retrograde Intrarenal Surgery for Large Renal Stones in Pediatric Patients: A Randomized Controlled Trial

PURPOSE

We compared outcomes of percutaneous nephrolithotomy and retrograde intrarenal surgery in the treatment of children with renal calculi larger than 2 cm.

MATERIALS AND METHODS

A total of 38 patients younger than 16 years with renal calculi larger than 2 cm were randomized to undergo percutaneous nephrolithotomy or retrograde intrarenal surgery between May 2011 and February 2014. Demographic data, stone criteria, operative technique, radiation time, complications, blood transfusion, hemoglobin decrease, stone-free rate and length of hospital stay were compared between the groups. Stone-free status was documented if there were no residual stones after 1 month.

RESULTS

The study included 43 renal units, of which 21 were subjected to retrograde intrarenal surgery and 22 to percutaneous nephrolithotomy. Operative time was comparable for both groups. Mean radiation time and hospital stay were longer after percutaneous nephrolithotomy (p<0.001). Stone-free rate was significantly lower after retrograde intrarenal surgery monotherapy vs percutaneous nephrolithotomy monotherapy (71% vs 95.5%, p=0.046). Patients in the percutaneous nephrolithotomy group had significantly more complications compared to the retrograde intrarenal surgery group (p=0.018). Three patients in the percutaneous nephrolithotomy group received blood transfusions, compared to none in the retrograde intrarenal surgery group (p=0.015).

CONCLUSIONS

For treatment of large or complex renal stones in pediatric patients percutaneous nephrolithotomy monotherapy has the advantage of better stone-free rates, while retrograde intrarenal surgery has the advantages of decreased radiation exposure, fewer complications and shorter hospital stay.

Underuse of 24-hour urine collection among children with incident urinary stones: a quality-of-care concern?

OBJECTIVE

To determine the prevalence of 24-hour urine collection among first-time pediatric stone formers and investigate factors associated with its use.

MATERIALS AND METHODS

Using data from the MarketScan Commercial Claims and Encounters Database (2002-2006), children presenting to the emergency department with an incident episode of upper urinary tract stone disease were identified through a diagnosis code-based algorithm. The number of patients performing a 24-hour urine collection within 6 months of this encounter was calculated. Temporal trends in the prevalence of use were assessed. We fitted multivariate logistic regression models to examine factors associated with testing.

RESULTS

In total, 1848 children presented with an incident upper tract stone, of which 12.0% submitted a 24-hour urine collection. This percentage remained stable over the study period. Testing was more common among younger patients (P <.001) and those who visited urologists (P <.001) or nephrologists (P <.001). The odds of testing were nearly 4-fold or 7-fold higher if the patient saw a urologist (odds ratio, 3.99; 95% confidence interval, 2.83-5.62) or a nephrologist (odds ratio, 7.00; 95% confidence interval, 3.95-12.41), respectively.

CONCLUSION

Despite rates of stone recurrence, 24-hour urine collection appears to be underused among children. Efforts to increase its use are therefore likely to benefit pediatric patients with urinary stone disease.

High incidence of urinary stones in Uyghur children may be related to local environmental factors

OBJECTIVE

To analyze the causes of urolithiasis in Uyghur children from Xinjiang.

PATIENTS AND METHODS

We retrospectively evaluated the clinical features and characteristics of urinary stone composition of 220 Uyghur pediatric patients with urolithiasis between March 2009 and June 2011. The data were compared with that of 100 Uyghur children without urolithiasis who visited the Child Care Clinic for regular health check-ups. The stones were collected by endoscopy or open surgery, and analyzed using infrared spectroscopy.

RESULTS

The mean age of the 220 Uyghur children was 7.48 ± 4.73 years (range, 0.8-17.0 years). The overall sex ratio (male:female) was 2.23:1. The predominant pure stone was ammonium urate (58.9%), whereas the predominant mixed stone was calcium oxalate mixture (91.1%). Uric acid stones comprised 54% of all stones. Urinary tract infections were observed in 42.3% and 4.0% of the patient and control groups, respectively. The mean urinary pH values were 5.77 ± 0.67 and 6.42 ± 0.67, respectively (p < 0.001). pH values were <5.5 in 52.7% and 6% of the patient and control groups, respectively. On 24-h urine analysis, we found metabolic disturbances in these patients: hypercalciuria in 6.8% cases, hyperphosphaturia in 16.8% cases, hyperuricosuria in 21.4% cases, and hypomagnesiuria in 34.1% cases.

CONCLUSIONS

Urolithiasis in Uyghur children may be primarily related to local environmental factors.

Comparison of Nephrolithiasis Prevalence in Two Bottlenose Dolphin (Tursiops truncatus) Populations

In humans, ammonium urate (AU) nephrolithiasis is rare in the Western hemisphere and more common in Japan and developing countries. Among a variety of risk factors, insulin resistance has been associated with urate nephrolithiasis in people. Bottlenose dolphins (Tursiops truncatus) are susceptible to AU nephrolithiasis, and it is believed that some populations are more likely to develop nephrolithiasis compared to others. In an effort to better understand population-based risk factors for AU nephrolithiasis in dolphins and their comparative value to humans, sonographic evaluation was performed on dolphins from a managed collection in San Diego Bay, CA (n = 40) and dolphins from a free-ranging, nearshore population in Sarasota Bay, FL (n = 39) to look for evidence of nephrolithiasis. While 14 (35%) of San Diego Bay dolphins evaluated for the study had sonographic evidence of nephrolithiasis, none of the Sarasota Bay dolphins had evidence of disease. Presence or absence of stones was confirmed by computed tomography in a subset of the San Diego collection (n = 10; four dolphins with stones, six without stones). Age was identified as a risk factor, as dolphins with stones in the San Diego collection were significantly older than dolphins without stones (25.4 vs. 19.1 years, respectively; P = 0.04). Additionally, San Diego dolphins included in the study were significantly older than Sarasota Bay dolphins (21.3 vs. 13.8 years, respectively; P = 0.008). In addition to the previously reported risk factors of hypocitraturia and hyperinsulinemia in bottlenose dolphins, other potential factors include geographic location, managed vs. free-ranging status, prey species, and feeding schedules.

Dietary factors and risk of kidney stone: a case-control study in southern China

OBJECTIVE

Formation of kidney stones is a multifactorial disease, and diet and lifestyle are suggested to contribute remarkably to increased prevalence. The population of Guangzhou, China has a high prevalence rate of kidney stones; however, its risk factors are still unknown. The aim of this study was to investigate the dietary risk factors for kidney stones in southern China.

DESIGN

A case-control study was carried out.

SETTING

This study was carried out at the Department of Health Management Center, Guangzhou Nanfang Hospital, China.

SUBJECTS

This study involved 1,019 newly diagnosed kidney stone patients and 987 healthy control subjects.

INTERVENTION

A questionnaire regarding dietary patterns and supplements was used to investigate the risk factors for kidney stone formation.

MAIN OUTCOME MEASURE

Food intake frequency, beverage and alcohol consumption, food supplements, and anthropometry were assessed.

RESULTS

In the analysis, we found positive associations of kidney stones with consumption of grains (odds ratio [OR] = 2.08; 95% confidence interval [CI] = 1.08, 4.02) and bean products (OR = 3.50; 95% CI = 1.61, 7.59) in women. The variable "fluid drinking" showed a significant protective effect against kidney stones in men (OR = 0.57; 95% CI = 0.36, 0.88). Consuming leafy vegetables more than 3 times per day was positively associated with stones in both men and women (OR = 2.02; 95% CI = 1.04, 3.91 and OR = 3.86; 95% CI = 1.48, 10.04, respectively). Other dietary factors, dietary supplements, and specific food were not related to kidney stone formation in Guangzhou, China.

CONCLUSION

The results confirmed that specific diet can affect stone formation in the Chinese population, and varied risk factors were found for different genders.

Risk factors associated with nephrolithiasis: a case-control study in China

Nephrolithiasis is a multifactorial disease. The authors conducted a case-control study in China to explore its associated risk factors. A total of 725 nephrolithiasis patients and 553 controls were asked to complete a questionnaire that asked for information about psychological, behavioral, and dietary factors along with a physical and blood biochemical examination. For men, higher education was negatively associated with nephrolithiasis (odds ratio [OR] = 0.6; 95% confidence interval [CI] = 0.4-1.0), whereas hypso-waist-to-hip ratio (hypso-WHR), defined as WHRs >0.9 for men and >0.8 for women (OR = 2.2; 95% CI = 1.4-3.4); overexercise (OR = 2.1; 95% CI = 1.3-3.5); and having experienced negative life events (OR = 2.2; 95% CI = 1.2-4.1) were positively associated with nephrolithiasis. For women, higher fluid intake was negatively associated with nephrolithiasis (OR = 0.6; 95% CI = 0.3-0.9), and abnormal status of blood pressure (BP) and blood lipids was positively associated with nephrolithiasis. Varied factors were related to differences in nephrolithiasis occurrence between genders. Besides taking enough fluids, maintaining a normal metabolic status, avoiding overexercise, and reducing BP might be beneficial in preventing nephrolithiasis.