Nephrolithiasis

2018 ◽  
Author(s):  
José Luiz Nishiura ◽  
Ita Pfeferman Heilberg

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.

2017 ◽  
Author(s):  
José Luiz Nishiura ◽  
Ita Pfeferman Heilberg

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.


2017 ◽  
Author(s):  
José Luiz Nishiura ◽  
Ita Pfeferman Heilberg

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.


2018 ◽  
Author(s):  
José Luiz Nishiura ◽  
Ita Pfeferman Heilberg

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.


2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Bao-Song Gui ◽  
Rong Xie ◽  
Xiu-Qiong Yao ◽  
Mei-Ru Li ◽  
Jian-Ming Ouyang

The composition and morphology of nanocrystals in urines of healthy persons and lithogenic patients were comparatively investigated by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was shown that the main composition of urinary nanocrystals in healthy persons were calcium oxalate dihydrate (COD), uric acid, and ammonium magnesium phosphate (struvite). However, the main compositions of urinary nanocrystals in lithogenic patients were struvite,β-tricalcium phosphate, uric acid, COD, and calcium oxalate monohydrate (COM). According to the XRD data, the size of nanocrystals was calculated to be23∼72 nm in healthy urine and12∼118 nm in lithogenic urine by Scherer formula. TEM results showed that the nanocrystals in healthy urine were dispersive and uniform with a mean size of about 38 nm. In contrast, the nanocrystals in lithogenic urine were much aggregated with a mean size of about 55 nm. The results in this work indicated that the urinary stone formation may be prevented by diminishing the aggregation and the size differentiation of urinary nanocrystals by physical or chemical methods.


Author(s):  
Rama Kishan Saran ◽  
Pawan Katti ◽  
Kiran Mirdha ◽  
Sanya Saran ◽  
Rajendra Prasad Takhar

Background: Pediatric urolithiasis results in significant morbidity in later life. Incidence as well as site and chemical composition of calculi varies according to the changes in socio-economic conditions over time and the subsequent changes in dietary habits leading to a marked variation in the spectrum of urinary stone composition. To evaluate the spectrum of urinary stone composition in pediatric population from North-western India.Methods: This was a prospective observational study conducted between October 2013 and February 2019 which included pediatric patients with urolithiasis. Demographic and epidemiological characteristics including age, sex, geography, religion, socio-economic status, dietary habits were recorded. The location and sizes of stones were documented. The data was collected, analyzed and presented using summary statistics.Results: A total of 163 patients with urolithiasis were enrolled, of which 86 (53%) aged between 6 and 10 years, 49 (30%) aged between 11 and 14 years and 28 (17%) were aged between 0 and 5 years. The majority of patients were male (n=134; 82.21%). The most common location of the stone was urinary bladder (n=106; 65.03%) followed by kidney (n=33; 20.25%), urethra (n=16; 9.82%) and ureter (n=8; 4.91%). The upper tract (kidney and ureter) to the lower tract (bladder and urethra) stone ratio was 1:4. Stones with mixed composition were more than pure stones (73.62% versus 26.38%). The most common composition was the mixed stone of calcium oxalate, calcium phosphate and uric acid (n=36; 22.09%) followed by mixed stone of calcium oxalate monohydrate and dihydrate with uric acid (n=29; 17.79%), calcium oxalate and uric acid (n=25, 15.34%), calcium oxalate and calcium phosphate (n=20; 12.27%). Calcium oxalate was present in 80% of the stones, followed by uric acid in 7%, struvite in 6%, cystine in 3% and calcium phosphate in 2%.Conclusions: These results suggest that the prevalence of mixed stones with calcium oxalate as the predominant chemical component in the urinary stones of pediatric patients studied.


1996 ◽  
Vol 89 (10) ◽  
pp. 561-562 ◽  
Author(s):  
Richard W Norman

Twenty-four-hour urine collections are an important part of the metabolic evaluation of stone-formers, but are difficult for patients at work. At weekends the results might be different. Forty-five stone-formers who worked at day jobs from Monday to Friday collected urine for 24 h on a normal working day and also on a Saturday or Sunday and the differences were evaluated. Average 24 h urine volume was higher on weekdays than at weekends. Calcium, oxalate, and uric acid excretion did not differ. These results imply an increased risk of crystalluria at the weekend. Therefore weekend collections are most likely to show abnormalities and should be acceptable to clinicians.


1975 ◽  
Vol 49 (6) ◽  
pp. 597-602 ◽  
Author(s):  
W. G. Robertson ◽  
M. Peacock ◽  
R. W. Marshall ◽  
R. Speed ◽  
B. E. C. Nordin

1. A retrospective cross-sectional study was carried out on data derived from single 24 h urine collections from 246 male idiopathic calcium stone-formers. 2. The daily urine volume and pH and the excretions of calcium, oxalate, phosphate, creatinine and magnesium were related to the time of year when the urine was collected, and the saturation of urine with calcium oxalate and octocalcium phosphate calculated for each month. 3. There were significant seasonal variations in the urinary excretion of calcium and oxalate, each showing a maximum during the summer months and a minimum in the winter. There was no significant seasonal variation in urinary pH, volume, creatinine, phosphate or magnesium. 4. There was a significant increase in the saturation of urine with calcium oxalate and a trend towards higher saturation levels of octo-calcium phosphate in the summer. These changes were dependent only on the seasonal variation in urinary calcium and oxalate and not on urine volume. 5. A retrospective study of the seasonal incidence of stone episodes among these 246 stone-formers showed that the rate of stone passage per month was 50% higher in the summer than in the winter. There was no significant seasonal variation in the incidence of stones removed surgically.


Urolithiasis ◽  
2020 ◽  
Vol 48 (5) ◽  
pp. 425-433 ◽  
Author(s):  
Juri Sromicki ◽  
Bernhard Hess

Abstract Among 208 kidney stone patients referred within 2 years, 75 patients (66 men, nine women) with truly idiopathic calcium oxalate stones (ICSF) were recruited. Dietary advice (DA) aimed at (1) urine dilution, (2) reduced crystallization promotion (lowering oxalate), and (3) increased crystallization inhibition (increasing citrate). We recommended higher intakes of fluid and calcium with meals/snacks (reducing intestinal oxalate absorption) as well as increased alkali and reduced meat protein (acid) for increasing urinary citrate. The intended effects of DA were elevations in urine volume, calcium (U-Ca) and citrate (U-Cit) as well as reductions in oxalate (U-Ox) and uric acid (U-UA). We retrospectively calculated an adherence score (AS), awarding + 1 point for parameters altered in the intended direction and − 1 point for opposite changes. Calcium oxalate supersaturation (CaOx-SS) was calculated using Tiselius’ AP(CaOx) index EQ. DA induced changes (all p < 0.0001) in urine volume (2057 ± 79 vs. 2573 ± 71 ml/day) and U-Ca (5.49 ± 0.24 vs. 7.98 ± 0.38 mmol/day) as well as in U-Ox (0.34 ± 0.01 vs. 0.26 ± 0.01 mmol/day) and U-UA (3.48 ± 0.12 vs. 3.13 ± 0.10 mmol/day). U-Cit only tendentially increased (3.07 ± 0.17 vs. 3.36 ± 0.23 mmol/day, p = 0.06). DA induced a 21.5% drop in AP(CaOx) index, from 0.93 ± 0.05 to 0.73 ± 0.05 (p = 0.0005). Decreases in CaOx-SS correlated with AS (R = 0.448, p < 0.0005), and highest AS (+ 5) always indicated lowering of CaOx-SS. Thus, simple DA can reduce CaOx-SS which may be monitored by AS.


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