The Impact of Dietary Modifications and Medical Management on 24-Hour Urinary Metabolic Profiles and the Status of Renal Stone Disease in Recurrent Stone Formers.

BACKGROUND: Dietary modifications and patient-tailored medical management are significant in controlling renal stone disease. Nevertheless, the literature regarding effectiveness is sparse. OBJECTIVES: To explore the impact of dietary modifications and medical management on 24-hour urinary metabolic profiles (UMP) and renal stone status in recurrent kidney stone formers. METHODS: We reviewed our prospective registry database of patients treated for nephrolithiasis. Data included age, sex, 24-hour UMP, and stone burden before treatment. Under individual treatment, patients were followed at 6-8 month intervals with repeat 24-hour UMP and radiographic images. Nephrolithiasis-related events (e.g., surgery, renal colic) were also recorded. We included patients with established long-term follow-up prior to the initiation of designated treatment, comparing individual nephrolithiasis status before and after treatment initiation. RESULTS: Inclusion criteria were met by 44 patients. Median age at treatment start was 60.5 (50.2-70.2) years. Male:Female ratio was 3.9:1. Median follow-up was 10 (6-25) years and 5 (3-6) years before and after initiation of medical and dietary treatment, respectively. Metabolic abnormalities detected included: hypocitraturia (95.5%), low urine volume (56.8%), hypercalciuria (45.5%), hyperoxaluria (40.9%), and hyperuricosuria (13.6%). Repeat 24-hour UMP under appropriate diet and medical treatment revealed a progressive increase in citrate levels compared to baseline and significantly decreased calcium levels (P = 0.001 and 0.03, respectively). A significant decrease was observed in stone burden (P = 0.001) and overall nephrolithiasis-related events. CONCLUSIONS: Dietary modifications and medical management significantly aid in correcting urinary metabolic abnormalities. Consequently, reduced nehprolithiasis-related events and better stone burden control is expected.

Dietary and pharmacologic management to prevent recurrent nephrolithiasis in adults: a clinical practice guideline from the American College of Physicians.

DESCRIPTION: The American College of Physicians (ACP) developed this guideline to present the evidence and provide clinical recommendations on the comparative effectiveness and safety of preventive dietary and pharmacologic management of recurrent nephrolithiasis in adults. METHODS: This guideline is based on published literature on this topic that was identified using MEDLINE, the Cochrane Database of Systematic Reviews (through March 2014), Google Scholar, ClinicalTrials.gov, and Web of Science. Searches were limited to English-language publications. The clinical outcomes evaluated for this guideline include symptomatic stone recurrence, pain, urinary tract obstruction with acute renal impairment, infection, procedure-related illness, emergency department visits, hospitalizations, quality of life, and end-stage renal disease. This guideline grades the quality of evidence and strength of recommendations using ACP's clinical practice guidelines grading system. The target audience for this guideline is all clinicians, and the target patient population is all adults with recurrent nephrolithiasis (≥1 prior kidney stone episode). RECOMMENDATION 1: ACP recommends management with increased fluid intake spread throughout the day to achieve at least 2 L of urine per day to prevent recurrent nephrolithiasis. (Grade: weak recommendation, low-quality evidence). RECOMMENDATION 2: ACP recommends pharmacologic monotherapy with a thiazide diuretic, citrate, or allopurinol to prevent recurrent nephrolithiasis in patients with active disease in which increased fluid intake fails to reduce the formation of stones. (Grade: weak recommendation, moderate-quality evidence).

[Nephrolithiasis: metabolic defects and terapeutic implications]. / Nefrolitiasi: aspetti metabolici e implicazioni terapeutiche.

Over the past 10 years, major progress has been made in the knowledge of urinary lithogenesis, including the potential pathogenetic role of Randall's plaques and renal tubular crystal retention. Urine supersaturation is the driving force of this process and can be induced by some risk factors, including low urine volume, high urinary excretion of calcium oxalate and uric acid and low urinary excretion of citrate. Primary hypercalciuria can be due to intestinal overabsorption renal leak and bone reabsorption of calcium. Prophilaxis is mainly conducted with thiazides and low calcium diet which is indicated only in the intestinal form. Primary hyperoxaluria is treated with pyridoxine and may require in the severe forms simultaneous renal and liver transplantation. Enteric hyperoxaluria is secondary to fatty acids malabsorption and requires diet, oral calcium and cholestiramine. Hyperuricosuria is caused by diet endogenous overproduction, mainly due to enzymatic defects or high renal excretion of uric acid. Urine alkalinization with K or K and Mg citrate can prevent stone formation even in idiopathic uric acid nephrolithiasis, in which a defect of urine acidification is supposed to be the main abnormality, and in hypocitraturic patients. Cystinuria is a rare inherited defect with an intense clinical impact. It can be classified in three forms and urinary stone formation is the role. Increased solubility and conversion of cystine in a more soluble form are the main goals of the prophylaxis which includes K citrate and thiol agents administration. Tiopronin is preferred to D-penicillamine due to its lower side effects.

Carbonate apatite nephrolithiasis associated with Corynebacterium urealyticum urinary tract infection in a dog.

BACKGROUND: Urinary tract infections caused by Corynebacterium urealyticum are uncommon in veterinary medicine. Encrusted cystitis, encrusted pyelitis and uroliths have been described as complications in humans, but only encrusted cystitis and cystoliths have been reported in dogs so far. Because C. urealyticum is usually resistant to all standard antibacterial drugs, antimicrobial treatment and elimination of this microorganism are challenging. CASE REPORT: An 11-month-old female spayed mixed-breed dog was evaluated because of a C. urealyticum urinary tract infection, mineralisation within both renal pelvises and failure of antimicrobial treatment. Physical examination, haematology and biochemistry were unremarkable. Radiographic and ultrasonographic examinations confirmed bilateral nephrolithiasis. Voided uroliths were composed of 100% carbonate apatite. Urinalysis was indicative of bacterial infection. Aerobic culture of the urine and 16S rRNA sequencing identified significant growth of C. urealyticum and susceptibility testing revealed sensitivity to only vancomycin and linezolid. CONCLUSION: Treatment with the oxazolidinone antibacterial, linezolid, in combination with a urine-acidifying diet resulted in elimination of this multiresistant microorganism and complete resolution of nephrolithiasis.

La dieta en el tratamiento de la litiasis renal. Bases fisiopatológicas / [Diet in the treatment of renal lithiasis. Pathophysiological basis].

The composition of urine is influenced by diet and changes in dietary factors have been proposed to modify the risk of recurrent nephrolithiasis. Nutrients that have been implicated include calcium, oxalate, sodium, animal protein, magnesium and potassium. There is significant evidence showing that a high calcium diet is associated with a reduction of lithogenic risk. One of the possible mechanisms to explain this apparent paradox is that the higher intake of calcium in the intestine binds with dietary oxalate, reducing its absorption and urinary excretion. Oxalate from the diet seems to provide only a small contribution to excretion and dietary restriction is appropriate only in those with hyperoxaluria and hyperabsorption. Observational studies have shown a positive and independent association between sodium intake and the formation of new kidney stones. Consumption of animal protein creates an acid load that increases urinary excretion of calcium and uric acid and reduced citrate, all factors that could participate in the genesis of stones. Potassium-rich foods increase urinary citrate because of its alkali content. In prospective observational studies, diets rich in magnesium were associated with a lower risk of kidney stone formation in men. In conclusion, diet is a key element in the management of the patient with kidney stones but always subordinated to present metabolic risk factors.

Medical management to prevent recurrent nephrolithiasis in adults: a systematic review for an American College of Physicians Clinical Guideline.

BACKGROUND: Optimum management to prevent recurrent kidney stones is uncertain. PURPOSE: To evaluate the benefits and harms of interventions to prevent recurrent kidney stones. DATA SOURCES: MEDLINE, Cochrane, and other databases through September 2012 and reference lists of systematic reviews and randomized, controlled trials (RCTs). STUDY SELECTION: 28 English-language RCTs that studied treatments to prevent recurrent kidney stones and reported stone outcomes. DATA EXTRACTION: One reviewer extracted data, a second checked accuracy, and 2 independently rated quality and graded strength of evidence. DATA SYNTHESIS: In patients with 1 past calcium stone, low-strength evidence showed that increased fluid intake halved recurrent composite stone risk compared with no treatment (relative risk [RR], 0.45 [95% CI, 0.24 to 0.84]). Low-strength evidence showed that reducing soft-drink consumption decreased recurrent symptomatic stone risk (RR, 0.83 [CI, 0.71 to 0.98]). In patients with multiple past calcium stones, most of whom were receiving increased fluid intake, moderate-strength evidence showed that thiazides (RR, 0.52 [CI, 0.39 to 0.69]), citrates (RR, 0.25 [CI, 0.14 to 0.44]), and allopurinol (RR, 0.59 [CI, 0.42 to 0.84]) each further reduced composite stone recurrence risk compared with placebo or control, although the benefit from allopurinol seemed limited to patients with baseline hyperuricemia or hyperuricosuria. Other baseline biochemistry measures did not allow prediction of treatment efficacy. Low-strength evidence showed that neither citrate nor allopurinol combined with thiazide was superior to thiazide alone. There were few withdrawals among patients with increased fluid intake, many among those with other dietary interventions and more among those who received thiazide and citrate than among control patients. Reporting of adverse events was poor. LIMITATIONS: Most trial participants had idiopathic calcium stones. Nearly all studies reported a composite (including asymptomatic) stone recurrence outcome. CONCLUSION: In patients with 1 past calcium stone, increased fluid intake reduced recurrence risk. In patients with multiple past calcium stones, addition of thiazide, citrate, or allopurinol further reduced risk. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality.

A case-control study of the effects of nephrolithiasis in cats with chronic kidney disease.

OBJECTIVE: To determine whether nephrolithiasis was associated with an increase in mortality rate or in the rate of disease progression in cats with naturally occurring stage 2 (mild) or 3 (moderate) chronic kidney disease. DESIGN: Retrospective case-control study. ANIMALS: 14 cats with stage 2 (mild) or 3 (moderate) chronic kidney disease (7 with nephroliths and 7 without). PROCEDURES: All cats were evaluated every 3 months for up to 24 months. Possible associations between nephrolithiasis and clinicopathologic abnormalities, incidence of uremic crises, death secondary to renal causes, and death secondary to any cause were evaluated. RESULTS: There were no clinically important differences in biochemical, hematologic, or urinalysis variables between cats with and without nephroliths at baseline or after 12 and 24 months of monitoring. No associations were detected between nephrolithiasis and rate of disease progression, incidence of uremic crises, or death. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that in cats with mild or moderate chronic kidney disease, nephrolithiasis was not associated with an increase in mortality rate or in the rate of disease progression. Findings support recommendations that cats with severe kidney disease and nephrolithiasis be managed without surgery.