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Khashayar Sakhaee - One of the best experts on this subject based on the ideXlab platform.
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Net Acid Excretion and Urinary Organic Anions in Idiopathic Uric Acid Nephrolithiasis.
Clinical Journal of the American Society of Nephrology, 2019Co-Authors: I. Alexandru Bobulescu, Khashayar Sakhaee, Beverley Adams-huet, Sun K. Park, Francisco J. Blanco, John R. Poindexter, Taylor L. Davidson, Naim M. Maalouf, Orson W. MoeAbstract:Background and objectives Idiopathic uric acid Nephrolithiasis, which is closely associated with obesity and the metabolic syndrome, is increasing in prevalence. Unduly acidic urine pH, the quintessential pathophysiologic feature of this disease, is in part explained by inadequate excretion of the principal urinary buffer ammonium. The role of net acid excretion in the pathogenesis of uric acid Nephrolithiasis is incompletely understood. Design, setting, participants, & measurements We compared acid-base parameters of patients with idiopathic uric acid Nephrolithiasis with matched control subjects under controlled diets in an inpatient metabolic unit. Measurements included fasting blood and 24-hour urine chemistries and 24-hour urine metabolomic analysis. Comparisons between groups included analysis of covariance models controlling for urine pH or body mass index. Results Subjects with idiopathic uric acid Nephrolithiasis had lower urine pH (5.5 versus 5.9; P Conclusions Higher acid load to the kidney, resulting in higher urinary net acid excretion, is an important factor in the pathogenesis of idiopathic uric acid Nephrolithiasis.
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Epidemiology and clinical pathophysiology of uric acid kidney stones
Journal of Nephrology, 2014Co-Authors: Khashayar SakhaeeAbstract:There is global diversity in the prevalence of uric acid (UA) Nephrolithiasis. UA Nephrolithiasis comprises 8–10 % of all kidney stones in the United States. However, its prevalence is higher in patients with type 2 diabetes mellitus and those with obesity. Three significant urinary abnormalities have been described as the main etiologic factors for the development of UA Nephrolithiasis; low urinary pH, hyperuricosuria and low urinary volume. However, an unduly acidic urine below the ionization constant of uric acid (pKa
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Nephrolithiasis in topiramate users
Urological research, 2010Co-Authors: Naim M. Maalouf, Orson W. Moe, Joshua P. Langston, Paul C. Van Ness, Khashayar SakhaeeAbstract:Topiramate is a neuromodulatory agent increasingly prescribed for a number of neurological and non-neurological indications. Topiramate-treated patients are at risk for Nephrolithiasis due to hypocitraturia and high urine pH. However, the prevalence of symptomatic stone disease in TPM users is generally perceived to be low. This study was undertaken to assess in topiramate-treated patients the prevalence of symptomatic Nephrolithiasis (by history) and of asymptomatic Nephrolithiasis by computed tomography (CT) scan. Topiramate users were identified from a database of patients with neurological disorders at a single university hospital. Among 75 topiramate-treated adult patients with a median daily dose of 300 mg and median treatment duration of 48 months, the prevalence of symptomatic Nephrolithiasis was 10.7%. In a subset of topiramate-treated patients and no history of symptomatic stone disease, the prevalence of asymptomatic Nephrolithiasis detected by CT scan was 20%. The prevalence of symptomatic Nephrolithiasis with long-term topiramate use is higher than reported in short-term studies. Furthermore, clinical prevalence is underestimated due to asymptomatic Nephrolithiasis.
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Nephrolithiasis-associated bone disease: pathogenesis and treatment options
Kidney international, 2010Co-Authors: Khashayar Sakhaee, Naim M. Maalouf, Rajiv Kumar, Andreas Pasch, Orson W. MoeAbstract:Nephrolithiasis remains a formidable health problem in the United States and worldwide. A very important but underaddressed area in Nephrolithiasis is the accompanying bone disease. Epidemiologic studies have shown that osteoporotic fractures occur more frequently in patients with Nephrolithiasis than in the general population. Decreased bone mineral density and defects in bone remodeling are commonly encountered in patients with calcium Nephrolithiasis. The pathophysiologic connection of bone defects to kidney stones is unknown. Hypercalciuria and hypocitraturia are two important risk factors for stone disease, and treatments with thiazide diuretics and alkali, respectively, have been shown to be useful in preventing stone recurrence in small prospective trials. However, no studies have examined the efficacy of these agents or other therapies in preventing continued bone loss in calcium stone formers. This manuscript reviews the epidemiology, pathophysiology, and potential treatments of bone disease in patients with Nephrolithiasis.
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postmenopausal hormone use and the risk of Nephrolithiasis results from the women s health initiative hormone therapy trials
JAMA Internal Medicine, 2010Co-Authors: Naim M. Maalouf, Khashayar Sakhaee, Alicia H Sato, Brian J Welch, Barbara V Howard, Barbara B Cochrane, John A RobbinsAbstract:Background Observational studies examining the role of estrogen in the risk of kidney stone formation have shown conflicting results. However, randomized trial evidence on Nephrolithiasis risk with estrogen therapy in postmenopausal women is lacking. Methods We reviewed the incidence of Nephrolithiasis in the Women's Health Initiative estrogen-alone and estrogen plus progestin trials conducted at 40 US clinical centers. A total of 10 739 postmenopausal women with hysterectomy were randomized to receive 0.625 mg/d of conjugated equine estrogens (CEE) or placebo, and 16 608 postmenopausal women without hysterectomy were randomized to receive placebo or estrogen plus progestin given as CEE plus medroxyprogesterone acetate (2.5 mg/d). The incidence of Nephrolithiasis was determined for an average follow-up of 7.1 years for the CEE trial and 5.6 years for the estrogen plus progestin trial. Results Baseline demographic characteristics and risk factors for Nephrolithiasis were similar in the placebo and treatment arms. Estrogen therapy was associated with a significant increase in Nephrolithiasis risk from 34 to 39 cases per 10 000 person-years (hazard ratio, 1.21; 95% confidence interval, 1.03-1.44). Censoring data from women when they ceased to adhere to study medication increased the hazard ratio to 1.39 (95% confidence interval, 1.08-1.78). The increased Nephrolithiasis risk was independent of progestin coadministration, and effects did not vary significantly according to prerandomization history of Nephrolithiasis. Conclusions These data suggest that estrogen therapy increases the risk of Nephrolithiasis in healthy postmenopausal women. These findings should be considered in decision making regarding postmenopausal estrogen use. The mechanisms underlying this higher susceptibility remain to be determined. Trial Registration clinicaltrials.gov Identifier:NCT0000611
F. Gary Cunningham - One of the best experts on this subject based on the ideXlab platform.
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Symptomatic Nephrolithiasis complicating pregnancy
Obstetrics & Gynecology, 2000Co-Authors: Erin L. Butler, Susan M. Cox, Eric G. Eberts, F. Gary CunninghamAbstract:Abstract Objective: To review our experiences with diagnosis and management of symptomatic Nephrolithiasis complicating pregnancy and to ascertain the efficacy of renal sonography for initial diagnosis compared with plain x-rays or single-shot intravenous pyelography. Methods: Perinatal outcomes were evaluated for all pregnant women admitted to Parkland Hospital for Nephrolithiasis from 1986 to 1999. Diagnostic studies and management of Nephrolithiasis were also evaluated. Results: During the 13-year study period, 57 pregnant women had 73 admissions for symptomatic Nephrolithiasis. Symptomatic Nephrolithiasis complicated 1 in 3300 (0.03%) deliveries at our institution. Only 12 women (20%) had a history of renal calculi. Mean gestational age at diagnosis was 23 weeks. Imaging techniques included renal ultrasonography, plain abdominal x-ray, and single-shot intravenous pyelography. Calculi were visualized in 21 of 35 (60%) renal ultrasonographic examinations and 4 of 7 (57%) abdominal x-ray studies when these were performed as the initial test. In contrast, urolithiasis was discovered in 13 of 14 (93%) instances in which intravenous pyelography was performed as the initial diagnostic test. When sonography was negative (n = 14), renal calculi were confirmed by single-shot intravenous pyelography (n = 8). Although 43 of 57 (75%) of symptomatic episodes responded to conservative management, 10 women required ureteral stents, 3 needed percutaneous nephrostomy tubes, and 2 underwent ureteral laser lithotripsy for resolution. Conclusion: Although the convenience and safety of ultrasonography to initially diagnose Nephrolithiasis are indisputable, 40% of calculi were missed when this method alone was used. Thus, if Nephrolithiasis is still suspected clinically despite ultrasonographic findings, single-shot pyelography is recommended.
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Symptomatic Nephrolithiasis complicating pregnancy.
Obstetrics and gynecology, 2000Co-Authors: Erin L. Butler, Susan M. Cox, Eric G. Eberts, F. Gary CunninghamAbstract:To review our experiences with diagnosis and management of symptomatic Nephrolithiasis complicating pregnancy and to ascertain the efficacy of renal sonography for initial diagnosis compared with plain x-rays or single-shot intravenous pyelography. Perinatal outcomes were evaluated for all pregnant women admitted to Parkland Hospital for Nephrolithiasis from 1986 to 1999. Diagnostic studies and management of Nephrolithiasis were also evaluated. During the 13-year study period, 57 pregnant women had 73 admissions for symptomatic Nephrolithiasis. Symptomatic Nephrolithiasis complicated 1 in 3300 (0.03%) deliveries at our institution. Only 12 women (20%) had a history of renal calculi. Mean gestational age at diagnosis was 23 weeks. Imaging techniques included renal ultrasonography, plain abdominal x-ray, and single-shot intravenous pyelography. Calculi were visualized in 21 of 35 (60%) renal ultrasonographic examinations and 4 of 7 (57%) abdominal x-ray studies when these were performed as the initial test. In contrast, urolithiasis was discovered in 13 of 14 (93%) instances in which intravenous pyelography was performed as the initial diagnostic test. When sonography was negative (n = 14), renal calculi were confirmed by single-shot intravenous pyelography (n = 8). Although 43 of 57 (75%) of symptomatic episodes responded to conservative management, 10 women required ureteral stents, 3 needed percutaneous nephrostomy tubes, and 2 underwent ureteral laser lithotripsy for resolution. Although the convenience and safety of ultrasonography to initially diagnose Nephrolithiasis are indisputable, 40% of calculi were missed when this method alone was used. Thus, if Nephrolithiasis is still suspected clinically despite ultrasonographic findings, single-shot pyelography is recommended.
Orson W. Moe - One of the best experts on this subject based on the ideXlab platform.
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Net Acid Excretion and Urinary Organic Anions in Idiopathic Uric Acid Nephrolithiasis.
Clinical Journal of the American Society of Nephrology, 2019Co-Authors: I. Alexandru Bobulescu, Khashayar Sakhaee, Beverley Adams-huet, Sun K. Park, Francisco J. Blanco, John R. Poindexter, Taylor L. Davidson, Naim M. Maalouf, Orson W. MoeAbstract:Background and objectives Idiopathic uric acid Nephrolithiasis, which is closely associated with obesity and the metabolic syndrome, is increasing in prevalence. Unduly acidic urine pH, the quintessential pathophysiologic feature of this disease, is in part explained by inadequate excretion of the principal urinary buffer ammonium. The role of net acid excretion in the pathogenesis of uric acid Nephrolithiasis is incompletely understood. Design, setting, participants, & measurements We compared acid-base parameters of patients with idiopathic uric acid Nephrolithiasis with matched control subjects under controlled diets in an inpatient metabolic unit. Measurements included fasting blood and 24-hour urine chemistries and 24-hour urine metabolomic analysis. Comparisons between groups included analysis of covariance models controlling for urine pH or body mass index. Results Subjects with idiopathic uric acid Nephrolithiasis had lower urine pH (5.5 versus 5.9; P Conclusions Higher acid load to the kidney, resulting in higher urinary net acid excretion, is an important factor in the pathogenesis of idiopathic uric acid Nephrolithiasis.
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Nephrolithiasis in topiramate users
Urological research, 2010Co-Authors: Naim M. Maalouf, Orson W. Moe, Joshua P. Langston, Paul C. Van Ness, Khashayar SakhaeeAbstract:Topiramate is a neuromodulatory agent increasingly prescribed for a number of neurological and non-neurological indications. Topiramate-treated patients are at risk for Nephrolithiasis due to hypocitraturia and high urine pH. However, the prevalence of symptomatic stone disease in TPM users is generally perceived to be low. This study was undertaken to assess in topiramate-treated patients the prevalence of symptomatic Nephrolithiasis (by history) and of asymptomatic Nephrolithiasis by computed tomography (CT) scan. Topiramate users were identified from a database of patients with neurological disorders at a single university hospital. Among 75 topiramate-treated adult patients with a median daily dose of 300 mg and median treatment duration of 48 months, the prevalence of symptomatic Nephrolithiasis was 10.7%. In a subset of topiramate-treated patients and no history of symptomatic stone disease, the prevalence of asymptomatic Nephrolithiasis detected by CT scan was 20%. The prevalence of symptomatic Nephrolithiasis with long-term topiramate use is higher than reported in short-term studies. Furthermore, clinical prevalence is underestimated due to asymptomatic Nephrolithiasis.
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Nephrolithiasis-associated bone disease: pathogenesis and treatment options
Kidney international, 2010Co-Authors: Khashayar Sakhaee, Naim M. Maalouf, Rajiv Kumar, Andreas Pasch, Orson W. MoeAbstract:Nephrolithiasis remains a formidable health problem in the United States and worldwide. A very important but underaddressed area in Nephrolithiasis is the accompanying bone disease. Epidemiologic studies have shown that osteoporotic fractures occur more frequently in patients with Nephrolithiasis than in the general population. Decreased bone mineral density and defects in bone remodeling are commonly encountered in patients with calcium Nephrolithiasis. The pathophysiologic connection of bone defects to kidney stones is unknown. Hypercalciuria and hypocitraturia are two important risk factors for stone disease, and treatments with thiazide diuretics and alkali, respectively, have been shown to be useful in preventing stone recurrence in small prospective trials. However, no studies have examined the efficacy of these agents or other therapies in preventing continued bone loss in calcium stone formers. This manuscript reviews the epidemiology, pathophysiology, and potential treatments of bone disease in patients with Nephrolithiasis.
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kidney stones pathophysiology and medical management
The Lancet, 2006Co-Authors: Orson W. MoeAbstract:Summary The formation of stones in the urinary tract stems from a wide range of underlying disorders. That clinicians look for the underlying causes for Nephrolithiasis is imperative to direct management. There are many advances in genetics, pathophysiology, diagnostic imaging, medical treatment, medical prevention, and surgical intervention of Nephrolithiasis. Here, I provide a brief general background and focus mainly on pathophysiology and medical treatment of kidney stones. Although important advances have been made in understanding Nephrolithiasis from single gene defects, the understanding of polygenetic causes of kidney stones is still largely elusive. A substantial proportion of data that resulted in new methods of treatment and prevention, which can be empirical or definitive, has focused on urinary luminal chemical composition of the precipitating solutes. Manipulation of inhibitors and epithelial factors is important and needs further investigation. Advances in the management of Nephrolithiasis depend on combined efforts of clinicians and scientists to understand the pathophysiology.
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pathophysiologic basis for normouricosuric uric acid Nephrolithiasis
Kidney International, 2002Co-Authors: Khashayar Sakhaee, Orson W. Moe, Beverley Adamshuet, Charles Y C PakAbstract:Pathophysiologic basis for normouricosuric uric acid Nephrolithiasis. Background: Low urinary pH is the commonest and by far the most important factor in uric acid Nephrolithiasis but the reason(s) for this defect is (are) unknown. Patients with uric acid nephrolithaisis have normal acid-base parameters according conventional clinical tests. Methods: We studied steady-state plasma and urinary parameters of acid-base balance in subjects with normouricosuric pure uric acid stones. We also tested the ability of these subjects to excrete ammonium in response to an acute acid load. We compared these parameters in patients with pure uric acid stones to patients with mixed uric acid/calcium oxalate stones, pure calcium stones, and normal volunteers. Results: Pure uric acid stone formers have a much higher incidence of either diabetes or glucose intolerance. After equilibration to a control diet, patients with uric acid stones have lower urinary pH and they excrete less of their acid as ammonium. This is compensated by higher titratable acidity and hypocitraturia. Despite their low baseline urinary pH, uric acid stone formers further acidify their urine after an acid load because of a severely impaired ammonia excretory response. Their characteristics are significantly different from normal volunteers and pure calcium stone formers. Patients with mixed uric acid/calcium stones exhibit intermediate characteristics. Conclusion: We propose that certain patients with normouricosuric uric acid Nephrolithiasis have a renal acidification disease. The primary defect lies in renal ammonium excretion, which may be linked to the insulin-resistant state. Although net acid excretion is maintained at the expense of increased titratable acidity and to some degree hypocitraturia, the compromise is acid urine pH and may result in uric acid Nephrolithiasis.
Laura Soldati - One of the best experts on this subject based on the ideXlab platform.
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Nephrolithiasis: nutrition as cause or therapeutic tool
Journal of translational medicine, 2013Co-Authors: Irene Brenna, Elena Dogliotti, Annalisa Terranegra, Benedetta Raspini, Laura SoldatiAbstract:Nephrolithiasis is a very common disease with an increasing prevalence among industrialized populations. Kidney stone formation is a complex phenomenon, involving genetic and metabolic patterns, and nutrition can play an important role in this match both as a promoter or as a protective factor. To promote a deeper knowledge of such a challenging disease, clinicians and researchers have met in Rome, Italy, last March 2013, at the International Congress “Nephrolithiasis: a systemic disorder” to discuss patho-physiology and possible treatment of kidney stones. During the meeting, a whole session was dedicated to nutrition, seen both as a cause or a therapeutic tool for Nephrolithiasis. Due to its etiopathogenesis, Nephrolithiasis is also an ideal model for a nutrigenetics and nutrigenomics approach. Nutrigenomics and nutrigenetic respectively study the effects of a dietary treatment on gene expression and, on the other hand, the impact of an inherited trait on the response to a specific dietary treatment.
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Nutrition in calcium Nephrolithiasis
Journal of translational medicine, 2013Co-Authors: Elena Dogliotti, Giuseppe Vezzoli, Antonio Nouvenne, Tiziana Meschi, Annalisa Terranegra, Alessandra Mingione, Caterina Brasacchio, Benedetta Raspini, Daniele Cusi, Laura SoldatiAbstract:Idiopathic calcium Nephrolithiasis is a multifactorial disease with a complex pathogenesis due to genetic and environmental factors. The importance of social and health effects of Nephrolithiasis is further highlighted by the strong tendency to relapse of the disease. Long-term prospective studies show a peak of disease recurrence within 2–3 years since onset, 40-50% of patients have a recurrence after 5 years and more than 50-60% after 10 years. International nutritional studies demonstrated that nutritional habits are relevant in therapy and prevention approaches of Nephrolithiasis. Water, right intake of calcium, low intake of sodium, high levels of urinary citrate are certainly important for the primary and secondary prevention of Nephrolithiasis. In this review is discussed how the correction of nutritional mistakes can reduce the incidence of recurrent Nephrolithiasis.
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Genetics and calcium Nephrolithiasis
Kidney international, 2010Co-Authors: Giuseppe Vezzoli, Annalisa Terranegra, Teresa Arcidiacono, Laura SoldatiAbstract:Calcium Nephrolithiasis is one of the most prevalent uronephrologic disorders in the western countries. Studies in families and twins evidenced a genetic predisposition to calcium Nephrolithiasis. Family-based or case–control studies of single-candidate genes evidenced the possible involvement of calcium-sensing receptor ( CASR ), vitamin D receptor ( VDR ), and osteopontin ( OPN ) gene polymorphisms in stone formation. The only high-throughput genome-wide association study identified claudin 14 ( CLDN14 ) gene as a possible major gene of Nephrolithiasis. Specific phenotypes were related with these genes: CASR gene in normocitraturic patients, VDR gene in hypocitraturic patients with severe clinical course, and CLDN14 gene in hypercalciuric patients. The pathogenetic weight of these genes remains unclear, but an alteration of their expression may occur in stone formers. Technological skills, accurate clinical examination, and a detailed phenotype description are the basis to get new insight about the genetic basis of Nephrolithiasis.
Erin L. Butler - One of the best experts on this subject based on the ideXlab platform.
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Symptomatic Nephrolithiasis complicating pregnancy
Obstetrics & Gynecology, 2000Co-Authors: Erin L. Butler, Susan M. Cox, Eric G. Eberts, F. Gary CunninghamAbstract:Abstract Objective: To review our experiences with diagnosis and management of symptomatic Nephrolithiasis complicating pregnancy and to ascertain the efficacy of renal sonography for initial diagnosis compared with plain x-rays or single-shot intravenous pyelography. Methods: Perinatal outcomes were evaluated for all pregnant women admitted to Parkland Hospital for Nephrolithiasis from 1986 to 1999. Diagnostic studies and management of Nephrolithiasis were also evaluated. Results: During the 13-year study period, 57 pregnant women had 73 admissions for symptomatic Nephrolithiasis. Symptomatic Nephrolithiasis complicated 1 in 3300 (0.03%) deliveries at our institution. Only 12 women (20%) had a history of renal calculi. Mean gestational age at diagnosis was 23 weeks. Imaging techniques included renal ultrasonography, plain abdominal x-ray, and single-shot intravenous pyelography. Calculi were visualized in 21 of 35 (60%) renal ultrasonographic examinations and 4 of 7 (57%) abdominal x-ray studies when these were performed as the initial test. In contrast, urolithiasis was discovered in 13 of 14 (93%) instances in which intravenous pyelography was performed as the initial diagnostic test. When sonography was negative (n = 14), renal calculi were confirmed by single-shot intravenous pyelography (n = 8). Although 43 of 57 (75%) of symptomatic episodes responded to conservative management, 10 women required ureteral stents, 3 needed percutaneous nephrostomy tubes, and 2 underwent ureteral laser lithotripsy for resolution. Conclusion: Although the convenience and safety of ultrasonography to initially diagnose Nephrolithiasis are indisputable, 40% of calculi were missed when this method alone was used. Thus, if Nephrolithiasis is still suspected clinically despite ultrasonographic findings, single-shot pyelography is recommended.
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Symptomatic Nephrolithiasis complicating pregnancy.
Obstetrics and gynecology, 2000Co-Authors: Erin L. Butler, Susan M. Cox, Eric G. Eberts, F. Gary CunninghamAbstract:To review our experiences with diagnosis and management of symptomatic Nephrolithiasis complicating pregnancy and to ascertain the efficacy of renal sonography for initial diagnosis compared with plain x-rays or single-shot intravenous pyelography. Perinatal outcomes were evaluated for all pregnant women admitted to Parkland Hospital for Nephrolithiasis from 1986 to 1999. Diagnostic studies and management of Nephrolithiasis were also evaluated. During the 13-year study period, 57 pregnant women had 73 admissions for symptomatic Nephrolithiasis. Symptomatic Nephrolithiasis complicated 1 in 3300 (0.03%) deliveries at our institution. Only 12 women (20%) had a history of renal calculi. Mean gestational age at diagnosis was 23 weeks. Imaging techniques included renal ultrasonography, plain abdominal x-ray, and single-shot intravenous pyelography. Calculi were visualized in 21 of 35 (60%) renal ultrasonographic examinations and 4 of 7 (57%) abdominal x-ray studies when these were performed as the initial test. In contrast, urolithiasis was discovered in 13 of 14 (93%) instances in which intravenous pyelography was performed as the initial diagnostic test. When sonography was negative (n = 14), renal calculi were confirmed by single-shot intravenous pyelography (n = 8). Although 43 of 57 (75%) of symptomatic episodes responded to conservative management, 10 women required ureteral stents, 3 needed percutaneous nephrostomy tubes, and 2 underwent ureteral laser lithotripsy for resolution. Although the convenience and safety of ultrasonography to initially diagnose Nephrolithiasis are indisputable, 40% of calculi were missed when this method alone was used. Thus, if Nephrolithiasis is still suspected clinically despite ultrasonographic findings, single-shot pyelography is recommended.
