Low Urine Volume Research Articles

Nephrolithiasis

Nephrolithiasis is a highly prevalent condition, but its incidence varies depending on race, gender, and geographic location. Approximately half of patients form at least one recurrent stone within 10 years of the first episode. Renal stones are usually composed of calcium salts (calcium oxalate monohydrate or dihydrate, calcium phosphate), uric acid, or, less frequently, cystine and struvite (magnesium, ammonium, and phosphate). Calcium oxalate stones, the most commonly encountered ones, may result from urinary calcium oxalate precipitation on the Randall plaque, which is a hydroxyapatite deposit in the interstitium of the kidney medulla. Uric acid nephrolithiasis, which is common among patients with metabolic syndrome or diabetes mellitus, is caused by an excessively acidic urinary pH as a renal manifestation of insulin resistance. The medical evaluation of the kidney stone patient must be focused on identifying anatomic abnormalities of the urinary tract, associated systemic diseases, use of lithogenic drugs or supplements, and, mostly, urinary risk factors such as low urine volume, hypercalciuria, hyperuricosuria, hypocitraturia, hyperoxaluria, and abnormalities in urine pH that can be affected by dietary habits, environmental factors, and genetic traits. Metabolic evaluation requires a urinalysis, stone analysis (if available), serum chemistry, and urinary parameters, preferably obtained by two nonconsecutive 24-hour urine collections under a random diet. Targeted medication and dietary advice are effective to reduce the risk of recurrence. Clinical, radiologic, and laboratory follow-ups are needed to prevent stone growth and new stone formation, to assess treatment adherence or effectiveness to dietary recommendations, and to allow adjustment of pharmacologic treatment. This review contains 5 highly rendered figure, 3 tables, and 105 references.

Metabolic investigation in patients with nephrolithiasis.

ABSTRACTObjectiveTo evaluate the prevalence of metabolic disorders associated with nephrolithiasis in a female population.MethodsA retrospective study on 1,737 patients with evidence of recent formation of renal stones, being 54% females. The laboratory investigation consisted of at least two samples of blood and 24-hour urine to assess calcium, uric acid, citrate and creatinine levels, qualitative cystinuria, urinary pH following fasting and 12-hour water restriction, urine culture, serum creatinine and parathyroid hormone.ResultsThe most frequent alterations were hypercalciuria (40.9%), urinary tract infection (23.2%), hypocitraturia (22.4%), low urinary volume (20.5%) and hyperuricosuria (16%).ConclusionThe most frequent metabolic alterations in females were hypocitraturia, urinary tract infection, low urinary volume and hyperuricosuria.

Metabolic abnormalities and genitourinary tract anatomical alternations in patients with recurrent urolithiasis

Background: Preventing the recurrence of episodes of stone formation is the focus of interest for patients. This retrospective study aimed to determine the prevalence of metabolic abnormalities and anatomical alterations of the genitourinary tract in patients with recurrent urolithiasis. Methods: Patients who had recurrent renal calculi were included. Laboratory assessment was performed on two 24-hour samples of urine. The first 24-hour urine was a random specimen and the second was obtained after the patient had been on a sodium-, oxalate- and calcium-restricted diet for at least one week. The patients with hypercalciuria further underwent fasting and calcium load testing and were assessed in terms of parathyroid hormone levels. Urine culturing was conducted to rule out urinary tract infection. All patients were evaluated with ultrasound and intravenous pyelography for any anatomical abnormalities. Results: A total of 30 patients (20 male and 10 females) were included in the study. The most frequently found metabolic alterations were hypercalciuria, low urinary volume, urinary tract infection and hyperoxaluria. Anatomic alterations were found in 26.5% of patients, mainly in the form of renal cysts, pelvi-ureteric junction obstructions, horse shoe kidneys and atrophic kidney. Conclusions: 80% of patients with recurrent stone disease had some measure of metabolic abnormality to account for the disease. The use of two 24-hour urine samples significantly improved the detection rate of metabolic abnormalities compared to a single sample. The major limitation of this study was the small number of patients as well as the short study duration.

Characterization of Urolithiasis in Patients Following Lower Urinary Tract Reconstruction with Intestinal Segments.

Urinary diversion and augmentation cystoplasty are associated with long-term complications, including metabolic derangements, infectious complications, and urolithiasis. The aim of this series was to characterize upper and lower urinary tract (LUT) calculi in this population. A retrospective chart review was performed on all patients with a history of urinary diversion or augmentation cystoplasty who subsequently underwent treatment for urolithiasis between January 1998 and May 2015. Data collected included demographics, perioperative characteristics, type of reconstructive procedure, urine culture, stone analysis, and metabolic evaluation. A statistical analysis was performed. Ninety-nine patients were identified with a history of urolithiasis and incontinent urinary diversion (28), neobladder (21), continent cutaneous diversion (12), and augmentation cystoplasty (38). LUT stones were more common than upper tract stones in all except for incontinent diversions, which only had one lower tract stone (p = 0.0001). Twenty-three percent of stones were metabolic. Several metabolic derangements were noted, including hypocitraturia (100%), elevated urine pH (100%), low urine volume (70%), and hyperoxaluria (35%). There was a 44% rate of recurrent urolithiasis. Given the high rate of stone recurrence among patients with a history of urinary diversion and augmentation cystoplasty, all measures should be taken to prevent recurrent stones. In addition to actions aimed to prevent infectious stones such as bladder and pouch irrigation, we recommend these patients undergo a full metabolic workup with targeted dietary changes and medical therapies.

Editorial Comment

The authors present a retrospective review of 113 children who presented with a kidney stone over a 14-year period. 1 Bevill M. Kattula A. Cooper C.S. Storm D.W. The modern metabolic stone evaluation in children. Urology. 2016; https://doi.org/10.1016/j.urology.2016.09.058 Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar They sought to determine if metabolic or genetic diseases were common contributors to stone formation. Overall, they found low urine volume in 89% of their cohort, with hypocitraturia as the most common abnormality (68%) and hypercalciuria as the least common (11%). Due to the rarity of finding a metabolic or genetic abnormality on 24-hour urine analysis and serum studies, the authors suggest that children who present with their first kidney stone may not require a full metabolic workup as has been the norm in the past.

METABOLIC EVALUATION OF PATIENTS WITH RECURRENT AND MULTIPLE RENAL STONES: A PROSPECTIVE STUDY

ABSTRACTObjective: Renal stone disease has become an important clinical condition worldwide, and it results from a combination of several factors whichare biochemical, epidemiologic, and genetic in origin. Preventive measures are very important concerning stone disease and these measures greatlydepend on the type of stones. Performing a metabolic evaluation of stone patients to identify metabolic abnormality, if any, and treating the same helpsreduce the recurrence of stones. To identify and correct the metabolic risk factors of patients presenting with either recurrent, bilateral, or multiplestones and thereby reduce the recurrence of stones.Methods: A hospital-based prospective observational study, including collection of essential data of 100 patients and analyzing them for any metabolicabnormality.Results: Out of the 100 patients, 73 were males and 27 were females. The frequency of stone formation was high in the age group 51-60, eventhough age is not a significant factor. Only 55 patients underwent metabolic evaluation, in which 23 patients (41.8%) had a metabolic abnormality.The common abnormality found in this geographical area was hyperuricosuria (29.1%) followed by hypercalciuria (7.3%). Hypercalciuria was notstatistically significant, but hyperuricosuria and acidic urine pH were significant factors that contribute to stone formation.Conclusion: Metabolic evaluation is a must for renal stone patients which greatly help reduce the risk of stone recurrence. Hyperuricemia wasobserved to be the major abnormality followed by hypercalciuria. Acidic urine pH and low urine volume were other significant risk factors.Keywords: Nephrolithiasis, Metabolic evaluation, Hyperuricosuria, Hypercalciuria.

The Modern Metabolic Stone Evaluation in Children

To evaluate metabolic abnormalities in a contemporary pediatric population after their first stone episode. The incidence of pediatric nephrolithiasis is increasing and therefore the etiologies contributing to today's pediatric stone formation may also be changing. A retrospective review of all consecutive children presenting after their first kidney stone between 2000 and 2014 was performed. We compared demographic data, serum chemistry results, and 24-hour urine results and treatments. One hundred thirteen children with a mean age of 11 years (5 months to 18 years) who presented with their first kidney stone episode between 2000 and 2014 were evaluated. Sixteen patients (14%) were found to have an underlying genetic or systemic disease. Overall, there was a low rate of serum chemistry abnormalities. The most common abnormalities found within the 24-hour urine evaluation included low urine volume (89%) and hypocitraturia (68%). Hypercalciuria occurred rarely (11%). We identified a low rate of underlying genetic or systemic diseases contributing to modern pediatric stone presentation and an increased proportion of idiopathic stones. Our study differs from historical findings by identifying a low rate of hypercalciuria and a high rate of low urine volume and hypocitraturia, suggestive of changing metabolic abnormalities contributing to modern pediatric stone disease.

Patients Attending Shared Medical Appointments for Metabolic Stone Prevention Have Decreased Stone Risk Factors.

Shared medical appointments (SMAs) have decreased patients' wait time to initial stone clinic appointment, standardized education, and increased exposure to nutrition therapy. We assessed the effectiveness of SMAs in reducing patients' urinary stone risk factors. Patients who established care in our stone clinic in an SMA between March 2012 and August 2015 were sequentially identified. After eliminating those without follow-up urine collections or whose urinary creatinine excretion between the two collections varied by >40%, 113 patients were included (M:F 63:50; 54 ± 15 years; body mass index [BMI] 30.6 ± 6.7). Results from before and after the SMA were compared with those from a similar cohort of patients who attended individual patient appointments (IPAs) for their first stone clinic visit (n = 63; M:F 37:26; 54 ± 14 years; BMI 30.1 ± 8.2). All patients received individualized medical therapy for stone prevention. After medical and nutritional therapy, SMA patients with elevated risk(s) at baseline achieved significant reductions in uric acid, calcium, and sodium; p ≤ 0.001 for all. Those with low urine magnesium, low urine volume, low urine pH, and/or low urine citrate at baseline achieved increases; p ≤ 0.0008 for all. IPA patients with elevated baseline risk factors achieved reductions in oxalate and uric acid (p ≤ 0.004 for both) but neither calcium nor sodium and an increase in citrate (p = 0.003) but not magnesium. Patients from SMAs reduced their stone recurrence risk and compared favorably with patients from IPAs. Contributing factors may include shorter time from stone event to appointment and more standardized education for patients attending SMAs.

Collecting duct-specific knockout of nitric oxide synthase 3 impairs water excretion in a sex-dependent manner.

Nitric oxide (NO) inhibits collecting duct (CD) Na+ and water reabsorption. Mice with CD-specific knockout (KO) of NO synthase 1 (NOS1) have salt-sensitive hypertension. In contrast, the role of NOS3 in CD salt and water reabsorption is unknown. Mice with CD NOS3 KO were generated with loxP-flanked exons 9-12 (encodes the calmodulin binding site) of the NOS3 gene and the aquaporin-2 promoter-Cre transgene. There were no differences between control and CD NOS3 KO mice, irrespective of sex, in food intake, water intake, urine volume, urinary Na+ or K+ excretion, plasma renin concentration, blood pressure, or pulse during 7 days of normal (0.3%), high (3.17%), or low (0.03%) Na+ intake. Blood pressure was similar between genotypes during DOCA-high salt. CD NOS3 KO did not alter urine volume or urine osmolality after water deprivation. In contrast, CD NOS3 KO male, but not female, mice had lower urine volume and higher urine osmolality over the course of 7 days of water loading compared with control mice. Male, but not female, CD NOS3 KO mice had reduced urinary nitrite+nitrate excretion compared with controls after 7 days of water loading. Urine AVP and AVP-stimulated cAMP accumulation in isolated inner medullary CD were similar between genotypes. Western analysis did not reveal a significant effect of CD NOS3 KO on renal aquaporin expression. In summary, these data suggest that CD NOS3 may be involved in the diuretic response to a water load in a sex-specific manner; the mechanism of this effect remains to be determined.

Do Overweight and Obese Pediatric Stone Formers Have Differences in Metabolic Abnormalities Compared With Normal-weight Stone Formers?

To determine if 24-hour urinary parameters in children with nephrolithiasis across 4 institutions were influenced by body mass index (BMI). The 24-hour urinary parameters obtained from children with nephrolithiasis between 2000 and 2013 were stratified by BMI percentile ≥85th and <85th (overweight and obese patients vs healthy weight, respectively). A total of 206 children were included in the study. Exclusion criteria included patients with a history of spina bifida, neurogenic bladder, and cerebral palsy, and patients on medical treatment before the first 24-hour urine collection. Overweight and obese patients consisted of 35.4% of the cohort (n = 73). Metabolic abnormalities were present in 130 children (63.1%). The most common abnormality present in the <85th percentile was hypercalciuria (32.3%), and in the ≥85th percentile, hyperoxaluria (37.0%). Univariable and multivariable analyses revealed that overweight and obese children were more likely to have low urinary volume and elevated uric acid compared to normal-weight children. Although there is a link between stone formation and BMI in adults, no definitive conclusions have been proven in the pediatric literature. Our study indicates that stone-forming children who are overweight or obese have low urinary volume and elevated uric acid compared to normal-weight stone-forming children.

The challenge of cystine and struvite stone formers: clinical, metabolic and surgical assessment.

ABSTRACTPurpose:To compare the clinical, metabolic, and calculi characteristics of cystine and struvite stone patients after percutaneous nephrolithotripsy (PCNL).Material and Methods:Between January/2006-July/2013, 11 cystine stone patients were treated in our clinic. Of those, 3 were excluded due to incomplete follow-up. Eight cystine stone patients (2 with bilateral disease; 10 renal units-RU) were considered for further analysis. A cohort of 8 struvite stone formers (10RU) was matched having the same age, gender, body mass index (BMI) and Guys stone score. Analyzed parameters comprised demographic data, serum/urinary metabolic evaluation and surgical outcomes.Results:Both groups had 6 female patients. Groups were similar in regards to age, gender, BMI, stone burden, and serum creatinine (p=NS). All patients had PCNL as the first surgical treatment modality. Stone free rate (SFR) after the first PCNL tended to be lower (0%) in the cystine compared to the struvite group (40%)(p=0.08). Final SFR after secondary procedures increased to 70% in cystine and 80% in struvite patients (p=1.0); mean number of procedures to achieve stone free status was higher in the first group (3.57 vs. 2.0;p=0.028). Hypocitraturia was found in all patients, but struvite cases presented with lower mean urinary citrate levels (p=0.016). Other common abnormalities were elevated urinary pH (cystine 75% and struvite 62.5%;p=1.0) and low urinary volume (62.5%,37.5%;p=0.63).Conclusion:Multiple interventions and suboptimal stone free rates are trait of the significant stone burden of struvite and cystine patients. Underlying metabolic abnormalities characterized by increased urinary pH, hypocitraturia and low urinary volume are often encountered in both populations.

The cardiovascular system in familial hypocalciuric hypercalcemia: a cross-sectional study on physiological effects of inactivating variants in the calcium-sensing receptor gene.

Loss-of-function variants in the gene encoding the calcium-sensing receptor (CASR) result in familial hypocalciuric hypercalcemia (FHH), causing hypercalcemia with high normal or elevated parathyroid hormone levels. The CASR may also influence electrolyte and water homeostasis. It is unknown whether FHH affects cardiovascular health. We, therefore investigated whether FHH is associated with changes in the regulation of the cardiovascular system by measuring 24-h blood pressure (BP), arterial stiffness and vasoactive hormones. Cross-sectional study comparing 50 patients with FHH to age- and gender-matched controls. Studied subjects (69% women) had a mean age of 56years. A similar number of patients and controls (33%) were on treatment with antihypertensive drugs. Overall, no differences were found between groups in 24-h ambulatory BP or pulse wave velocity. However, compared with controls, diastolic BP during nighttime was lower in FHH females (60±5 vs 66±9mmHg, P<0.01) and higher in FHH males (69±6 vs 64±5mmHg, P=0.02). FHH was associated with a significantly higher plasma osmolality (P<0.01), higher plasma levels of vasopressin (P<0.01) and a higher renal excretion of epithelial sodium channels (ENaCs) (P=0.03), whereas urine aquaporin-2 and plasma sodium, aldosterone and renin did not differ between groups. FHH patients had a lower urinary volume with an increased osmolality if analyses were restricted to those not on treatments with antihypertensive drugs. FHH does not seem to be associated with an increased risk of CVD.

Renal Calculi-Prevalence, Risk Factors and Dietary Management:A Review

Civilizations have been suffered by renal calculi/calculi since centuries. Vedas have named calculi as Ashamari. Literature has described renal calculi as "The silent cause of renal failure". The prevalence of this ailment is not limited to India but to whole world. People not only from developing countries are suffering from this renal calculi but this ailment is wide spread in developed countries too. Studies have indicated that renal calculi mostly affects the most productive years of life i.e. 30-40 years of age. Males suffer more from renal calculi as compared to females. Metabolism, socioeconomic and dietary factors directly or indirectly has been responsible for this suffering. Nutrition is the key determinant in calculi formation. The increase in frequency of calculi is closely related to the genetic and environmental factors namely fluid intake, low urinary volume and high urine concentration due to warm climate, immobilization, occupation and certain medications. Metabolic disorders, heredity, water supply, alcohol consumption and smoking often have been blamed for calculi formation. More interesting fact is that calculi pass to generations. If proper counseling and guidance is provided to sufferers at the right time regarding dietary management depending upon the stage of the disease and condition of the patient, it can be proved to be helpful in preventing further complications including recurrence in the long run.

Whether a good uroflow rate could guarantee a low post-void residual urine volume in men with overactive bladder?

Whether a good uroflow rate could guarantee a low post-void residual urine volume in men with overactive bladder?

Uric acid bladder stones in congenital cyanotic heart disease

A 54-year-old man was admitted with a 4-year history of recurrent urinary tract infections. He had a history of osteoarthritis of the left hip and benign prostatic enlargement. Physical examination showed clubbing with cyanosis (fi gure), and a grade 4/6 systolic murmur throughout the praecordium. Electrocardiogram showed right ventricular hypertrophy with features of pressure overload (appendix). His haemoglobin was raised at 200 g/L, with a haematocrit of 0·53. A CT scan of the genitourinary system showed multiple large urinary bladder stones (fi gure), urinary bladder wall thickening, trabeculations and diverticulae, and bilateral hydroureters and hydronephrosis. Cardiac MRI showed features consistent with unrepaired tetralogy of Fallot, including a large ventricular septal defect with bidirectional shunting. Cardiac catheterisation showed normal coronary arteries and pulmonary vascular resistance. Ten large bladder stones were removed by open surgery, for symptom relief and to decompress the related obstructive uropathy, measuring up to 3·3 cm in diameter (fi gure). Gas chromatography-mass spectrometry showed that the stones were composed of uric acid. Our patient later had corrective surgery for prognostic and symptomatic improvement of his suprasystemic right ventricular systolic pressure and pulmonary stenosis. Patients with cyanotic heart disease have compensatory erythrocytosis as a physiological response to persistent hypoxia, associated with a shortened red blood cell lifespan. This can cause increased red cell turnover leading to high purine metabolism and uric acid production. The most common factors that promote uric acid stone formations are persistently low urinary pH, dehydration leading to low urinary volume, and high uric acid production. Nitrogen atoms from urate interact with free protons to form uric acid that is 20 times less soluble than urate. Low pH promotes urate conversion to uric acid, which is less soluble and so more prone to forming crystals. At persistently low pH uric acid crystals can form and stabilise even with normal urinary urate concentration. Intermittent alkalinisation of urine dissolves crystals that have formed and promotes urinary stone resorption, although patients with hyperuricosuria do not form uric acid stones in the presence of alkaline urine. The underlying physiology that leads to persistently low urinary pH is poorly understood. Oral agents to modify urinary pH are available, but minimally invasive surgery is the treatment of choice for patients with symptomatic urinary bladder stones. Our patient had slightly raised plasma uric acid, with normal 24-h urinary uric acid and plasma creatinine levels. The electronic patient record had recorded a persistently low urinary pH over the last few years. He now has regular urological follow-up. We suggest that hyperuricaemia combined with persistently low urinary pH, which led to bladder stone formation, was caused by appropriate secondary erythrocytosis, turnover, and breakdown in the setting of cyanotic congenital heart disease.

Characterizing ceftriaxone-induced urolithiasis and its associated acute kidney injury: an animal study and Chinese clinical systematic review.

To investigate the pathophysiological process of ceftriaxone-induced urolithiasis and its associated acute kidney injury (AKI) based on an animal study and summarize the main clinical characteristics based on a Chinese clinical systematic review. Male Sprague-Dawley rats were randomly divided into five groups of six each according to different treatments including control; ceftriaxone; ceftriaxone with calcium; calcium; and ceftriaxone, calcium with citrate, respectively. The 24-h urine volume, serum creatinine (Scr) and blood urea nitrogen (BUN) were measured; kidney histological examination and stone analysis were performed. Systematic searches of the Chinese Knowledge Database were conducted for reports on ceftriaxone-induced urolithiasis and AKI. The eligibility of each full-text publication was accessed, and qualified data were extracted and reviewed. Kidney stones and a significantly low 24-h urine volume with increased high Scr and BUN levels were found in the group that received ceftriaxone combined with calcium. Citrate was able to inhibit these biochemical changes and stone formations. A total of 161 qualified patients were included in the Chinese clinical systematic review: The proportion of ceftriaxone-induced urolithiasis was 21.1, 19.3, 19.3, 39.1 and 1.2% for ages <3, 3-6, 7-17, 18-60 and >60years. 72.7% developed acute kidney injury eventually. Ceftriaxone-induced urolithiasis was associated with a high risk of AKI. The pathophysiological process may be related to urinary obstruction and crystalline nephropathy. Citrate was able to inhibit stone formation and prevent further kidney injury.

Key influence of sex on urine volume and osmolality.

BackgroundDemographics influence kidney stone risk and the type of stone that is more likely to form. Common kidney stone risk factors include having a low urine volume and a high urine concentration. The goal of the current study was to evaluate the effect of demographics on urinary concentration and osmole excretion.MethodsTwenty-four-hour urine samples were collected from non-Hispanic white sibships in Rochester, MN. Height, weight, blood pressure, serum creatinine, and cystatin C were measured. Diet was assessed using the Viocare food frequency questionnaire. Effects of demographics and dietary elements on urine osmolality and volume were evaluated in bivariate and multivariable models, as well as models that included dietary interactions with age, sex, and weight.ResultsSamples were available from 709 individuals (mean age 66 ± 9 years, 59 % female). Across the age spectrum, males had higher urine osmolality (~140 mOsm/kg, p < 0.0001) and total osmole excretion (~270 mOsm, p < 0.0001) compared to females. For any given urine volume, males had a consistently higher urine osmolality (~140 mOsm/kg, p < 0.0001). In multivariable models, urine osmolality declined with age and water intake and remained higher in males than females. Urine osmolality positively associated with weight and animal protein intake. Higher urine volume associated with larger water intake. An interaction revealed that greater body weight was associated with larger changes in urine osmolality as oxalate intake increased (p = 0.04).ConclusionData from this study support the hypothesis that there are sex differences in thirst and vasopressin action. This trend in urine concentration is also consistent with known epidemiologic patterns of urinary stone disease risk.Electronic supplementary materialThe online version of this article (doi:10.1186/s13293-016-0063-0) contains supplementary material, which is available to authorized users.

The Effect of Increased Frequency of Hemodialysis on Volume-Related Outcomes: A Secondary Analysis of the Frequent Hemodialysis Network Trials

In previous reports of the Frequent Hemodialysis Network trials, frequent hemodialysis (HD) reduced extracellular fluid (ECF) and left ventricular mass (LVM), with more pronounced effects observed among patients with low urine volume (UVol). We analyzed the effect of frequent HD on interdialytic weight gain (IDWG) and a time-integrated estimate of ECF load (TIFL). We also explored whether volume and sodium loading contributed to the change in LVM over the study period. Treatment effects on volume parameters were analyzed for modification by UVol and the dialysate-to-serum sodium gradient. Predictors of change in LVM were determined using linear regression. Frequent HD reduced IDWG and TIFL in the Daily Trial. Among patients with UVol <100 ml/day, reduction in TIFL was associated with LVM reduction. This suggests that achievement of better volume control could attenuate changes in LVM associated with mortality and cardiovascular morbidity. TIFL may prove more useful than IDWG alone in guiding HD practice. Video Journal Club ‘Cappuccino with Claudio Ronco' at http://www.karger.com/?doi=441966.

Metabolic Evaluation in Paediatric Urolithiasis: A 4-Year Open Prospective Study.

Children with urolithiasis are associated with considerable morbidity and commonly associated with metabolic abnormalities. By treating these abnormalities stone formation is prevented. To study the metabolic risk factors of urolithiasis in children and compare them with literature. In open, prospective and observational study, 75 children were evaluated from August 2010 to June 2014. In all patients' dietary history, water intake and results of laboratory findings were recorded. All urine samples obtained from patients were without dietary restrictions. Reference paediatric 24 hour urinary parameter was used according to western literature. We investigated 75 patients with urolithiasis. Low urine volume was found in 49 patients which is comparable with previous studies indicating simple intervention as to increase water intake. Low calcium intake was found in 44 patients suggesting that low calcium intake is associated with higher incidence of urolithiasis due to increased intestinal oxalate absorption. Hypocalcaemia was found in 32 patients and 24 hour urinary abnormality was found in only 16 patients'. Both these finding does not support previous literature. Stone analysis finding does not correlate with urinary finding. Low urine volume secondary to low water intake is predominant finding. Hypocalcaemia is major metabolic abnormality in contradiction to western literature. There are no nomograms for urinary excretion of Calcium, uric acid, oxalate and citrate in Indian children. Keeping the optimum blood calcium level & increased fluid intake can prevent stone formation in children.

Metabolic Syndrome and Nephrolithiasis Risk: Should the Medical Management of Nephrolithiasis Include the Treatment of Metabolic Syndrome?

This article reviews the relationship between metabolic syndrome (MetS) and nephrolithiasis, as well as the clinical implications for patients with this dual diagnosis. MetS, estimated to affect 25% of adults in the United States, is associated with a fivefold increase in the risk of developing diabetes, a doubling of the risk of acquiring cardiovascular disease, and an increase in overall mortality. Defined as a syndrome, MetS is recognized clinically by numerous constitutive traits, including abdominal obesity, hypertension, dyslipidemia (elevated triglycerides, low high-density lipoprotein cholesterol), and hyperglycemia. Urologic complications of MetS include a 30% higher risk of nephrolithiasis, with an increased percentage of uric acid nephrolithiasis in the setting of hyperuricemia, hyperuricosuria, low urine pH, and low urinary volume. Current American Urological Association and European Association of Urology guidelines suggest investigating the etiology of nephrolithiasis in affected individuals; however, there is no specific goal of treating MetS as part of the medical management. Weight loss and exercise, the main lifestyle treatments of MetS, counter abdominal obesity and insulin resistance and reduce the incidence of cardiovascular events and the development of diabetes. These recommendations may offer a beneficial adjunctive treatment option for nephrolithiasis complicated by MetS. Although definitive therapeutic recommendations must await further studies, it seems both reasonable and justifiable for the urologist, as part of a multidisciplinary team, to recommend these important lifestyle changes to patients with both conditions. These recommendations should accompany the currently accepted management of nephrolithiasis.