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Background and objectives: ADV7103 is a new prolonged-release treatment for distal renal tubular acidosis (dRTA), containing potassium citrate and potassium bicarbonate. Since acidosis may affect bone mineral contents, the effects of ADV7103 on bone mineral density (BMD) and growth in patients with dRTA over 24 months were evaluated. Patients and methods: Thirty patients (24 paediatric patients and 6 adults) were included in an open-label extension study after a phase II/III trial. BMD, measured by densitometry, was assessed at baseline and at 24 months. Growth was evaluated throughout the study. Plasma bicarbonate, parathyroid hormone, 25-hydroxy vitamin D, 1,25-dihydroxy vitamin D, bone alkaline phosphatase, calciuria and citraturia, were also determined. Safety and treatment compliance were evaluated as well. Results: After 24 months of treatment with ADV7103, mean spine BMD z-score values significantly increased as compared with baseline (p = 0.024). In adults, spine and whole-body densitometry z-scores showed a significant correlation with plasma bicarbonate levels (rS = 0.82 and rS = 0.97, respectively, p 0.5 units in z-scores for height and weight in 18% and 36% of the paediatric patients, respectively. With treatment, plasma bicarbonate concentration and calciuria at the different visits were normal in 69–86% and 93–96% patients, respectively. Only nine treatment-related gastrointestinal AEs of mild/moderate severity, were reported in five patients. Conclusions: Two years of ADV7103 treatment improved growth and increased spine BMD. These results suggest that control of acidosis by ADV7103 treatment improves bone parameters. Resumen: Antecedentes y objetivo: El ADV7103 es un nuevo tratamiento de liberación prolongada para la acidosis tubular renal distal (ATRd), que contiene citrato potásico y bicarbonato potásico. Dado que la acidosis puede afectar al contenido mineral óseo, se ha evaluado el efecto de dicho medicamento a lo largo de 24 meses sobre la densidad mineral ósea (DMO) y el crecimiento en pacientes con ATRd. Pacientes y métodos: Se incluyeron treinta pacientes (24 pediátricos y seis adultos) en un estudio abierto de extensión tras un ensayo clínico de fase II/III. La DMO medida por densitometría se midió al inicio del estudio y los 24 meses. El crecimiento se evaluó a lo largo del estudio. Adicionalmente, se determinaron el bicarbonato plasmático, la parathormona, 25 hidroxivitamina D, 1,25 dihidroxivitamina D, fosfatasa alcalina ósea, calciuria y citraturia. La seguridad y el cumplimento terapéutico también fueron evaluados. Resultados: Tras 24 meses de tratamiento con ADV7103 la media del z-score de DMO de columna aumentó significativamente frente al valor basal (p = 0,024). En los adultos el z-score de la densitometría de columna y corporal total mostró una correlación significativa con los valores de bicarbonato plasmático (rS = 0,82 y rS = 0,97, respectivamente, p < 0,005). Se registró un incremento > 0,5 unidades de z-score para altura y peso en el 18 y 36%, respectivamente, de los pacientes pediátricos. Con el tratamiento, la concentración plasmática de bicarbonato y la calciuria fueron normales en las diferentes visitas en un 69-86% y un 93-96% de los pacientes, respectivamente. Solamente se notificaron nueve eventos adversos gastrointestinales relacionados con el tratamiento, todos de intensidad leve/moderada en cinco pacientes. Conclusiones: Dos años de tratamiento con ADV7103 mejoraron el crecimiento y la DMO de columna. Estos resultados sugieren que el control de la acidosis con dicho tratamiento provoca una mejora de parámetros óseos.

Nephrolithiasis, commonly known as kidney stone disease or urolithiasis, is a crystallopathy in which a solid mass forms in the urinary tract. The aim of the present research is to evaluate the way that albino rats administered with a highprotein diet, react to methanolic root extracts of Lagerstroemia speciosa anticalciuric properties. Medicinal plants are frequently utilised in folk medicine to treat a wide range of illnesses. Banaba is the common name for L. speciosa, a member of the Lythraceae family; Poomaruthu is its Tamil name. The test animals were given a diet high in protein and low in protein as well as 45 days of treatment with methanolic root extracts of L. speciosa. The experiment was scheduled with a sample collection, biochemical inquiries, and histopathological exams. The experiment had been scheduled with a sample collection, biochemical investigations, and histopathological evaluations. The biochemical data reveal that as compared to the control, III, and V groups, the low-protein diet groups II and IV had greater blood urea concentrations. The low-protein diet groups II and IV exhibited an increased blood creatinine concentration in contrast to the control, III, and V groups, while group V (H.P+MRE 500 mg/kg) demonstrated a nearly identical outcome to that of the control groups. L. speciosa root extracts in methanol are given to groups to control creatinine concentration. The normal control group's histopathological analysis revealed tubules with a single epithelial lining along the outermost layer that were normal in size. [ABSTRACT FROM AUTHOR]

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Contexto. La modificación de los hábitos alimentarios puede reducir la incidencia y la recurrencia de la urolitiasis (UL). Objetivo. Evaluar la influencia de la ingesta de carnes, frutas, hortalizas, huevos y lácteos en el riesgo de sobresaturación urinaria (RSU) en estudiantes sin antecedentes de UL. Metodología. Estudio correlacional de corte transversal con una muestra compuesta por estudiantes voluntarios sin antecedentes de UL en el periodo 2018-2019. Para este estudio se registraron datos personales, clínicos, ingesta diaria y semanal de los alimentos en estudio y se analizó la orina de 24h recogida el día que se completó el registro diario, además, el RSU se determinó con el programa EQUIL AT. Resultados. Participaron 61 estudiantes, 90?% mujeres, con un índice masa corporal y edad promedios de 22,8 Kg/m2 y 25 años. Presentaron RSU 33 mujeres y 4 hombres, por lo que se calculó un 92?% de RSU para ácido úrico. La ingesta diaria de carnes, huevos y quesos fue superior a lo requerido para una alimentación saludable y la de hortalizas, frutas, leche y yogur inferior. No hubo diferencias entre las ingestas del registro diario y semanal, donde los individuos con RSU tuvieron una mayor ingesta de carnes y una menor de frutas, hortalizas y huevos que aquellos sin RSU, siendo significativa la diferencia (p < 0,05). Conclusiones. Se hallaron diferencias significativas en la ingesta de carnes, frutas, hortalizas y huevos en los individuos con RSU respecto a aquellos sin RSU. La ingesta diaria fue la habitual, por lo que la sobresaturación sería continua en los individuos con riesgo. Se podría actuar preventivamente en la modificación de los hábitos alimentarios antes de que se forme el primer cálculo.

Background: Chronic hyponatremia is known to be associated with osteoporosis. It has been shown that chronic hyponatremia increases bone resorption in an attempt to release body stores of exchangeable sodium by different mechanisms. We wanted to know the calciuria of patients with hyponatremia of different origins. Material and Methods: We made a retrospective study of 114 consecutive patients with asymptomatic hyponatremia of different origins with the usual serum and urine chemistry. Result: In hyponatremia due to SIADH, we had a high urine calcium/creatinine ratio of 0.23 ± 0.096 while in patients with salt depletion the UCa/UCr ratio was low (0.056 ± 0.038), in patients with hyponatremia secondary to thiazide intake the value was also low (0.075 ± 0.047) as in hypervolemic patients (0.034 ± 0.01). In hyponatremia due to polydipsia, the value was high (0.205 ± 0.10). Correction of hyponatremia in the euvolemic patients was associated with a significant decrease in the UCa/UCr ratio. In patients with hyponatremia secondary to thiazide intake, we noted that in the patients with low uric acid levels (<4 mg/dL, suggesting euvolemia) we also observed a low UCa/UCr (<0.10). In nine patients with chronic SIADH (SNa 125.1 ± 3.6 mEq/L), the 24 h urine calcium excretion was 275 ± 112 mg and decreased to 122 ± 77 mg (p < 0.01) after at least 2 weeks of treatment. Conclusions: Patients with chronic hyponatremia due to SIADH usually have a high UCa/UCr ratio (>0.15). This is also observed in hyponatremia secondary to polydipsia. Patients with thiazide-induced hyponatremia usually have low UCa/UCr levels and this is the case even among those with a biochemistry similar to that in SIADH (uric acid < 4 mg/dL). [ABSTRACT FROM AUTHOR]

Background: We previously reported that for around 5% of patients hospitalized with hyponatremia, it was related to what is called "transient renal salt wasting" (TRSW). In the present study we ask whether TRSW can also be observed in patients without hyponatremia. Methods: In this observational retrospective study we analyze the urine solute excretion of 200 consecutive normonatremic patients with normal kidney function and admitted in our department over one year. Patients were selected for analyses of FE.K, UCa/UCr and FE.PO4 if FE.Na was higher than 2% (N < 1.6%) before any treatment, and only if they were not taking diuretics. Result: Eleven normonatremic patients presented with transient high FE.Na > 2% on admission (2.9 ± 0.6% with a high FE.K of 28 ± 6.4%; a high UCa/UCr of 0.37 ± 0.13 and a high FE.PO4 of 23.2 ± 9.6%). All of these patients were elderly. Seven were female and four were male. Neurological disorders were observed in six patients (three strokes, one transient ischemic attack, one syncope and one epileptic attack). Heart problems were observed in three patients (all angina pectoris, two of which also had HBP). One patient presented with rectal bleeding with HBP, and another presented COPD with a pneumothorax. One patient with angina pectoris showed a transient relapse after four days of hospitalization (FE.Na 3.6%). The urine electrolyte excretion in these patients are similar to those observed after furosemide intake. Conclusion: Normonatremic TRSW is not a rare observation, particularly in patients with neurological or cardiac problems. [ABSTRACT FROM AUTHOR]

Background: Carbonated beverages are very popular worldwide. Carbonated beverage consumption vast increase raises great health concerns regarding their effect on calcium homeostasis besides obesity and renal function. Carbonated beverages sugar content, caffeine, and acidulant all can affect in a way or another calcium absorption, metabolism and excretion. The latter has direct effect on teeth, bone and general wellbeing. This study aims to reveal the effect of sub-chronic intake of carbonated beverage on urinary pH, crystalluria, calcium excretion. Methods: 21 healthy volunteers have been recruited in this study (9 males and 12 females) abstain for any carbonated beverages for at least the previous 4 weeks before participating in this study. Urine has been collected over 24 hours, the next day each volunteer has to drink 250 ml of carbonated beverage (Pepsi®) daily for 3 weeks. On the last day, urine was collected again over 24hr. pH, crystalluria, and calcium in urine have been measured. Results: Urine pH and crystalluria after 3 weeks' intake of 250 ml of carbonated beverage did not statistically differ from urine pH before the intake. Although, there was a trend toward reduction in pH and an increase in crystalluria. Total calcium excretion in urine increase was statistically significant when compared with calcium excretion at the study beginning. Conclusion: The regular intake of carbonated beverage (Pepsi®) increase calcium excretion. Thus, it may be advisable to increase the intake of milk or other dairy product to overcome the adverse impact of carbonated beverages. [ABSTRACT FROM AUTHOR]

Resumen: Antecedentes y objetivos: La acidosis tubular renal distal (ATRd) es una enfermedad minoritaria, de origen genético o adquirido, caracterizada por una incapacidad de excreción urinaria de hidrogeniones (H+), hipobicarbonatemia, hipercloremia, hipocitraturia y habitualmente hipokaliemia e hipercalciuria. Las formas genéticas suelen diagnosticarse en los primeros meses de vida y su tratamiento consiste en suplementos de álcali encaminados a evitar las consecuencias clínicas a largo plazo, sobre todo la enfermedad renal crónica (presente en algunas series hasta en el 82% de los pacientes) y la enfermedad ósea asociada. Se desarrolló una encuesta multirrespuesta cerrada de 10 preguntas encaminada a conocer aspectos epidemiológicos, diagnósticos, del manejo clínico y terapéutico, dentro del colectivo de nefrólogos españoles. Materiales y métodos: Encuesta distribuida a los asistentes a un foro científico sobre ATRd durante el congreso de 2019 de la Sociedad Española de Nefrología (SEN); las respuestas se recogieron a la salida del mismo. Los resultados se analizaron con un test estadístico paramétrico estableciéndose el porcentaje de cada respuesta a las 10 preguntas. Resultados: De entre los que respondieron a la encuesta, el 44,4 y el 37,7% no atendieron a ningún paciente con ATRd en el último año ni en los tres anteriores, respectivamente. Cuando se sospecha la patología, el diagnóstico genético confirmatorio se realiza solo en el 13,3% de los casos y el estudio familiar solo en el 11,1%. Solo el 26,6% afirman que el control metabólico es excelente, bueno o muy bueno, y el 69% piensan que el cumplimiento terapéutico es regular, malo o muy malo. Conclusiones: La encuesta ha puesto de manifiesto el relativo desconocimiento de esta patología, así como la baja satisfacción con el control metabólico y el pobre cumplimiento terapéutico, lo cual puede conllevar una mayor severidad en la enfermedad renal y ósea asociadas a la ATRd. Abstract: Background and objectives: dRTA is a genetic or acquired rare disease, characterized by an unability to excrete hydrogens (H+) into urine, hypobicarbonatemia, hyperchloremia, and frequently hypercalciuria and hypokalaemia. Genetic forms are usually diagnosed during the first months of life and its treatment is based on providing alkali supplements in order to prevent long term clinical consequences, particularly chronic kidney disease (described in some cohorts up to 82% of dRTA patients) and the associated bone disease. A 10 queries multi choice closed response survey was designed to know more about epidemiological, diagnostics, clinical management and therapeutical issues of this disease among Spanish nephrologists. Materials and methods: This survey was delivered to the attendees to a scientific meeting on dRTA at the Spanish Nephrology Society congress in 2019. Surveys were collected at the end of this dRTA event. Results were analyzed by using a parametric statistical test, obtaining the percentage of each response for the 10 questions. Results: Among the survey responders, 44.4% and 37.7% did not visit any dRTA patient during the 1st and 3rd last year respectively. When having a suspicious diagnose, confirming genetic diagnostic test is only performed on the 13.3% of cases and pedigree studies only on 11.1%. Only a 26.6% confirms that metabolic control is excellent, good or very good, and 69% of the responders believe that treatment compliance is not bad, bad or very bad. Conclusions: This survey enhances the fact that dRTA is not a well known entity, satisfaction with metabolic control is poor and compliance is low. All these factors can lead to a higher severity of renal and bone diseases associated to dRTA.

Background and objectives: dRTA is a genetic or acquired rare disease, characterized by an unability to excrete hydrogens (H+) into urine, hypobicarbonatemia, hyperchloremia, and frequently hypercalciuria and hypokalaemia. Genetic forms are usually diagnosed during the first months of life and its treatment is based on providing alkali supplements in order to prevent long term clinical consequences, particularly chronic kidney disease (described in some cohorts up to 82% of dRTA patients) and the associated bone disease. A 10 queries multi choice closed response survey was designed to know more about epidemiological, diagnostics, clinical management and therapeutical issues of this disease among Spanish nephrologists. Methods and materials: This survey was delivered to the attendees to a scientific meeting on dRTA at the Spanish Nephrology Society congress in 2019. Surveys were collected at the end of this dRTA event. Results were analyzed by using a parametric statistical test, obtaining the percentage of each response for the 10 questions. Results. Among the survey responders, 44.4% and 37.7% did not visit any dRTA patient during the 1st and 3rd last year respectively. When having a suspicious diagnose, confirming genetic diagnostic test is only performed on the 13.3% of cases and pedigree studies only on 11.1%. Only a 26.6% confirms that metabolic control is excellent, good or very good. 69% of the responders believe that treatment compliance is not bad, bad or very bad. Conclusions: This survey enhances the fact that dRTA is not a well known entity, satisfaction with metabolic control is poor and compliance is low. All these factors can lead to a higher severity of renal and bone diseases associated to dRTA. Resumen: Antecedentes y objetivos: La ATRd es una enfermedad minoritaria de origen genético o adquirido, caracterizada por una incapacidad de excreción urinaria de hidrogeniones (H+), hipobicarbonatemia, hipercloremia, hipocitraturia y habitualmente hipokaliemia e hipercalciuria. Las formas genéticas suelen diagnosticarse en los primeros meses de vida y su tratamiento consiste en suplementos de álcali encaminados a evitar las consecuencias clínicas a largo plazo, sobre todo la enfermedad renal crónica (presente en algunas series hasta en el 82% de los pacientes) y la enfermedad ósea asociada. Se desarrolló una encuesta multirrespuesta cerrada de 10 preguntas encaminada a conocer aspectos epidemiológicos, diagnósticos, del manejo clínico y terapéutico, dentro del colectivo de nefrólogos españoles. Materiales y métodos: Encuesta distribuida a los asistentes a un foro científico sobre ATRd durante el congreso de 2019 de la Sociedad Española de Nefrología (SEN), se recogieron las respuestas a la salida del mismo. Los resultados se analizaron con un test estadístico paramétrico estableciéndose el porcentaje de cada respuesta las 10 preguntas. Resultados. De entre los que respondieron a la encuesta, un 44,4% y un 37,7% no atendió ningún paciente con ATRd en el último año ni en los 3 anteriores, respectivamente. Cuando se sospecha la patología, el diagnóstico genético confirmatorio se realiza solo en un 13,3% de los casos y el estudio familiar solo en un 11,1%. Solo un 26,6% afirma que el control metabólico es excelente, bueno o muy bueno, y el 69% piensa que el cumplimiento terapéutico es regular, malo o muy malo. Conclusiones: La encuesta ha puesto de manifiesto el relativo desconocimiento de esta patología, así como la baja satisfacción con el control metabólico y el pobre cumplimiento terapéutico, lo cual puede conllevar a una mayor severidad en la enfermedad renal y ósea asociadas a la ATRd.

ABSTRACT Objective Hypoparathyroidism is a rare condition, whose most common etiology is complications of neck surgery. The aim of the study was to identify the clinical and biochemical profile of the patients with diagnosis of hypoparathyroidism, including the frequency of symptoms, clinical signs, long-term complications and disease control. Additionally, the study sought to know what the medication profile was, and the doses required by the patients. Subjects and method A retrospective cohort study was conducted wherein all patients with ICD-10 codes associated with hypoparathyroidism between 2011 and 2018 at the Hospital Universitario San Vicente Fundación were included. We investigated the etiology of the disease; biochemical profile including lowest serum calcium, highest serum phosphorus, 25OHD levels, calciuria and calcium/phosphorus product; medication doses, disease control, and presence of complications, especially renal and neurologic complications were also evaluated. Results The cohort included 108 patients (99 women/9 men) with a mean age of 51.6 ± 15.6 years. The main etiology was postoperative (93.5%), the dose of elemental calcium received was relatively low (mean 1,164 mg/day), and in only 9.2% of cases more than 2,500 mg/day of elemental calcium was necessary. We were able to evaluate the follow-up in 89 patients, and found that only 57.3% met the criteria for controlled disease. Conclusion The clinical profile of patients with hypoparathyroidism in our cohort is similar to that described in other international studies, with predominantly postoperative etiology. With standard therapy, only adequate control is achieved in a little more than half of patients. Arch Endocrinol Metab. 2020;64(3):282-9

Parathyroidectomy (PTX) is routinely performed in hypercalciuric renal stone patients with primary hyperparathyroidism (PHPT). However, some data indicate a persistent stone activity following PTX, raising the issue of the link between PHPT and stone disease. We performed an observational study on 30 renal stone patients diagnosed with PHPT. Patients were selected among 1448 hypercalciuric patients referred in our department for a diagnostic evaluation. Patients with no parathyroid surgery or any biological follow-up were excluded. Clinical and biological data (including 24-h urine collection and a calcium load test) were collected before and within 12 months following surgery. Stone recurrence was evaluated by direct phone contact (median 43 months). Comparison of biological data before and after surgery showed a significant decrease of ionized calcium and serum parathyroid hormone after PTX. All stones contained calcium-dependent species such as carbapatite, brushite or dihydrate calcium oxalate. Urine saturation indexes and calciuria significantly decreased after surgery (from 9.9 to 5.9 mmol/d, p < 0.0001), but a persistent hypercalciuria was detected in 47% of patients. The other stone risk factors including diuresis stayed similar. Stone activity that was increasing (from 0.20–0.30 to 0.50–0.75/year) the 2 years before PTX, significantly decreased after surgery [0.05–0.15/year (p < 0.001)]. PTX in calcium-dependent renal stone formers with PHPT significantly decreases both stone recurrence and urine saturation indexes. However, PTX unmasked an underlying renal stone disease related to idiopathic hypercalciuria in half of patients with a remaining stone activity, testifying the need for patient's follow-up to prevent stone recurrence. [ABSTRACT FROM AUTHOR]

Introduction: Idiopathic hypercalciuria is defined as urine calcium excretion greater than 220 mg/day in women and 300 mg/day in men, or greater than 4 mg/kg under regular dietary conditions. Objective: The aim of this study is to review the diagnosis, classification, and treatment of hypercalciuric patients with renal lithiasis. Methods: We enrolled 250 patients suffering from renal lithiasis and idiopathic hypercalciuria and 80 healthy subjects as control group. Lab tests were performed to diagnose renal lithiasis. Results: Although the 24-hour urine test is the gold standard to determine calciuria, in this study we propose considering the Ca/Kg >4 mg/Kg ratio or an index of >140 mg of Ca per gram urine creatinine. Regarding the different types of hypercalciuria, after following a strict diet, subjects were divided into two groups: diet-dependent and diet-independent hypercalciuria. Concerning the treatment, we suggest diuretic therapy to achieve a urine output of 2-2.5 liters per day. In the case of subjects with diet-dependent hypercalciuria, we advise an intake of 600-800 mg of calcium and a moderate reduction in animal protein and salt intake. In cases of non-response to treatment in subjects with diet-dependent hypercalciuria, thiazides, chlorthalidone, indapamide and, in some cases, bisphosphonates may help control hypercalciuria with a lower risk of lithiasis recurrence and healthier bones. Conclusions: We believe it is important to consider not only the methods to diagnose hypercalciuria but also its classification to provide a better treatment. [ABSTRACT FROM AUTHOR]

Copyright of Nefrologia is the property of Revista Nefrologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background The antidiuretic hormone (ADH) or arginine vasopressin (AVP) regulates the body's water balance. Recently, modifications in AVP levels have been related to osteoporosis during ageing and microgravity/bed rest. Therefore the present study was devised to assess whether the absence of AVP, as in patients with central diabetes insipidus (CDI), modulates renal calcium excretion. Methods We retrospectively analysed data from 12 patients with CDI with measured 24-h urinary excretion levels of calcium. Data were available at the moment of the diagnosis when patients were drug-free and after therapy with dDAVP, an analog of AVP. Hypercalciuria was defined as 24-h urinary Ca2+ >275 mg/day in males and >250 mg/day in females and a urinary calcium (Ca):creatinine (Cr) ratio >0.20 mg/mg. Results Untreated CDI patients had a daily urinary Ca2+ excretion of 383 ± 47 mg/day and a urinary Ca:Cr ratio of 0.26 ± 0.38 mg/mg. The urine osmolarity significantly increased after the administration of dDAVP by 210% and the urinary flow decreased by 72%. Furthermore, the estimated glomerular filtration rate (eGFR) increased by 7%, which did not reach statistical significance. dDAVP treatment did not significantly modify the urinary Ca2+ concentration; however, the daily calcium excretion and the urinary Ca:Cr ratio were significantly decreased (160 ± 27 mg/day and 0.11 ± 0.02 mg/mg, respectively). Conclusions Patients with CDI show hypercalciuria even though urine is more diluted than normal controls, and dDAVP reverses this effect. These data support the intriguing relationship between AVP and osteoporosis in ageing and microgravity/bed rest. [ABSTRACT FROM AUTHOR]

Objective: We aimed to determine the relationship between serum vitamin D levels and urinary calcium excretion in patients with D vitamin deficiency. Material-Method: 319 volunteers without any chronic disease of 30-50 years were included in this study. Demographic data and complete blood count, serum 25-OH vitamin D, parathyroid hormone (PTH), calcium, albumin, phosphorus, thyroid stimulating hormone (TSH), magnesium, lipid profile (total cholesterol, triglyceride, LDL cholesterol, HDL cholesterol) alkalin phosphatase, creatinine and urinary calcium, creatinine levels were documented. Results: Of the 319 volunteers in our study; 265 were in the vitamin D deficiency group and 54 were in the control group (Vitamin D is in normal levels). Parathormone values were significantly higher in the vitamin D deficiency group than control group, while calcium values were found to be significantly lower. Calcium / creatinine ratio in the spot urine was 0.08±0.06 in the D deficiency group and 0.09±0.07 in the control group (p=0.197). No statistically significant difference was found between groups in terms of spot urine calcium/ creatinine ratio. Conclusions: Urinary calcium excretion was slightly decreased in patients with vitamin D deficiency, but there was no statistically significant difference in urinary calcium excretion between groups. Also there was no correlation between vitamin D levels and urinary calcium excretion. Our findings do not indicate enough evidence that calcium value in spot urine is a useful marker for detecting vitamin D deficiency. [ABSTRACT FROM AUTHOR]

Vitamin D deficiency is frequent in pediatric nephrology. The 2017 European guidelines recommend keeping 25OH vitamin D (25-D) levels within the 75-120 nmol/L range, ideally with daily supplementation. Intermittent supplementation with D3 has also been proposed. We aimed to assess the influence of our local protocol of intermittent vitamin D supplementation on the evolution of 25-D levels between baseline and 2 months. VITATOL is a prospective single-center study performed in our tertiary unit in children and teenagers followed for chronic kidney disease (CKD), kidney transplantation, or stable chronic nephrotic syndrome with 25-D levels below 75 nmol/L. Intermittent oral cholecalciferol (100,000 IU) was administered depending on baseline vitamin D levels and body weight. The primary outcome was the change in 25-D levels between baseline and 2 months. Secondary outcomes were the evolution of the main mineral biomarkers. Thirty-seven patients were included. Two months after beginning supplementation, corresponding to a median(min-max) of 46 (14-79) days after the last dose of vitamin D, 25-D levels increased from 50 to 76 nmol/L (p < 0.001), 18 patients having 25-D levels within the target range and 2 above. All patients displayed 25-D levels above 50 nmol/L. There were no significant changes in phosphate, PTH, alkaline phosphatase, and FGF23 levels before and after supplementation. Calcium levels increased from 2.39 to 2.44 mmol/L (p = 0.017), but no differences in calciuria and urinary calcium/creatinine ratio were observed.Conclusion: This vitamin D supplementation protocol using intermittent moderate doses of cholecalciferol seems efficient in 54% of cases, with neither significant overdose nor hypercalciuria. What is Known: • Vitamin D deficiency is frequent in pediatric nephrology. • The 2017 European guidelines recommend keeping 25OH vitamin D levels within the 75-120 nmol/L range ideally with daily supplementation, but intermittent supplementation with D3 has also been proposed. What is New: • We assessed the influence of a local protocol of intermittent vitamin D supplementation on the evolution of 25-D levels between baseline and 2 months in children and teenagers followed in pediatric nephrology. • The intermittent cholecalciferol supplementation protocol seems efficient in 54% of cases, with neither significant overdose nor hypercalciuria. [ABSTRACT FROM AUTHOR]

Recessive missense mutation in the solute carrier family 12, member 1 (SLC12A1 ) gene (g.62382825G>A) is associated with hydrallantois, which is the accumulation of fluid in the allantoic cavity of a pregnant animal, and usually causes fetal death in Japanese Black cattle. However, the symptoms of a homozygote with this mutation that do not result in fetal death have not previously been tracked and evaluated. In the present study, we observed a homozygote with the SLC12A1 risk allele over a long‐term period. The calf did not show any obvious clinical symptoms, although it did exhibit a slight growth retardation that accompanied mild calciuria. At 28 months of age, the homozygote showed renal dysfunction, which in turn resulted in hydronephrosis. The time course of the symptoms was consistent with the phenotype of Bartter syndrome in humans. Additionally, the risk heterozygous genotype did not any effects on carcass traits, which indicates that eliminating the risk allele would not have any unfavorable effects. Therefore, we emphasize that both the fetal‐ and late‐stage symptoms associated with the SLC12A1 risk allele compromise animal welfare, and consequently may result in severe economic losses for individual farmers if the SLC12A1 risk allele is not eliminated from the population. [ABSTRACT FROM AUTHOR]

Aim: Assessment of mineral metabolism is complex in paediatrics.Methods: We assessed the evolution of the main mineral and bone biomarkers (total/bone alkaline phosphatase ALP/BAP, β-crosslaps, osteocalcin, sclerostin, C-terminal and intact FGF23) in 100 healthy teenagers (10-18 years, 50 boys).Results: At a mean age of 13.7 ± 2.2 years, phosphatemia, tubular phosphate reabsorption, ALP and BAP significantly decreased along puberty in both genders, whilst parathyroid hormone (PTH), 25-vitamin D (25D), FGF23, plasma calcium and urinary calcium were not modified. In girls, osteocalcin, β-crosslaps and sclerostin significantly decreased at the end of puberty. Calciuria above the crystallisation threshold (>3.8 mmol/L) and urinary calcium/creatinine ratio >0.7 mmol/mmol were found in 39% and 6% of subjects, respectively. Multivariable analyses showed that renal function and PTH were significant predictors of calciuria and urinary calcium/creatinine, whilst 25D remained a predictor only of urinary calcium/creatinine ratio.Conclusion: Using the most recent assays, this study provides data for mineral/bone biomarkers across puberty and highlights the risk of hyper-calciuria in apparent asymptomatic healthy teenagers, not related to calcium intake but rather to 25D. Future studies are required to dissect the underlying mechanisms increasing calciuria and prevent nephrolithiasis as early as during childhood. [ABSTRACT FROM AUTHOR]

La reabsorción tubular de calcio es uno de los principales factores que determinan la concentración sérica de calcio y su excreción urinaria. El túbulo contorneado distal y conector es donde se produce la regulación fina de la calciuria. A ese nivel se encuentra el canal epitelial de Ca (TRPV5), que es el paso limitante en el transporte transcelular de Ca. La presencia dinámica del canal TRPV5 en la superficie de la célula tubular está mediada por un proceso de reciclado endosómico. Distintos factores intrarrenales intervienen en la fijación del canal de calcio en la membrana aplical, entre ellos la hormona antienvejecimiento klotho y la calicreína tisular (CT). Ambas proteínas son sintetizadas en el túbulo distal y secretadas en el fluido tubular. La calicreína tisular estimula la reabsorción activa de calcio por vía del receptor de bradiquinina tipo 2 que compromete la activación del of TRPV5 por vía de la protein cinasa C. Los ratones deficientes en CT muestran hipercalciuria de origen renal comparable a la pérdida de calcio que se observa en los ratones knockout para el TRPV5. Existe un polimorfismo con pérdida de función del gen de la CT humana denominado R53H (alelo H) que produce una gran disminución de la actividad enzimática. La presencia del alelo H, por lo menos en la población japonesa, parece ser frecuente (24%). Estos individuos tiene una tendencia a excreción más alta de calcio y sodio en orina que se manifiesta más durante la infusión de furosemida. En el futuro habrá que estudiar si la manipulación del sistema calicreína-quinina renal permite corregir la hipercalciuria idiopática con fármacos diferentes a los diuréticos tiazídicos.

Renal tubular calcium reabsorption is one of the principal factors that determine serum calcium concentration and calcium excretion. Calcium excretion is regulated by the distal convoluted tubule and connecting tubule, where the epithelial calcium channel TRPV5 can be found, which limits the rate of transcellular calcium transport. The dynamic presence of the TRPV5 channel on the surface of the tubular cell is mediated by an endosomal recycling process. Different intrarenal factors are involved in calcium channel fixation in the apical membrane, including the anti-ageing hormone klotho and tissue kallikrein (TK). Both proteins are synthesised in the distal tubule and secreted in the tubular fluid. TK stimulates active calcium reabsorption through the bradykinin receptor B2 that compromises TRPV5 activation through the protein kinase C pathway. TK-deficient mice show hypercalciuria of renal origin comparable to that seen in TRPV5 knockout mice. There is a polymorphism with loss of function of the human TK gene R53H (allele H) that causes a marked decrease in enzymatic activity. The presence of the allele H seems to be common at least in the Japanese population (24%). These individuals have a tendency to greater calcium and sodium excretion in urine that is more evident during furosemide infusion. Future studies should analyse if manipulating the renal kallikrein-kinin system can correct idiopathic hypercalciuria with drugs other than thiazide diuretics.

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Background: There is a paucity of data on blood pressures (BP), urinary albumin, and mineral excretion in early childhood in contemporary cohorts of extremely low gestational age (GA) neonates. Our aim was to compare BPs and the urinary excretion of albumin, calcium, and phosphate in preterm and term-born cohorts in early childhood. Methods: This was a prospective observational study conducted at a single center, involving children <5 years age, born preterm (GA <30 weeks) or at term (≥37 weeks' GA). Urinary albumin (mg/L), calcium and phosphate levels indexed to creatinine (mg/dL), and BP were measured. Results: The median (IQR) follow-up age of our cohort ( n = 106) was 30 (16-48) months. Preterm-born children ( n = 55) had a significantly lower mean GA and birth weight and higher mean systolic, diastolic, and mean BPs, compared with term ( n = 51) controls. A significantly higher proportion of preterm-born children weighed <10th centile and had systolic BP >95th centile at follow-up. Albumin and calcium excretion did not differ between the groups; median urine-phosphate creatinine ratios were higher in the preterm group. On logistic regression, lower GA and younger age at follow-up were significantly associated with an increased risk of systolic and diastolic BP above the 95th centile; male gender was associated with decreased risk of diastolic hypertension. Conclusions: Even in early childhood, children born preterm had significantly elevated BP, compared with their term-born counterparts. Closer monitoring of BPs in this population may be warranted. [ABSTRACT FROM AUTHOR]

Calcium (Ca2+) and Magnesium (Mg2+) reabsorption along the renal tubule is dependent on distinct trans- and paracellular pathways. Our understanding of the molecular machinery involved is increasing. Ca2+ and Mg2+ reclamation in kidney is dependent on a diverse array of proteins, which are important for both forming divalent cationpermeable pores and channels, but also for generating the necessary driving forces for Ca2+ and Mg2+ transport. Alterations in these molecular constituents can have profound effects on tubular Ca2+ and Mg2+ handling. Diuretics are used to treat a large range of clinical conditions, but most commonly for the management of blood pressure and fluid balance. The pharmacological targets of diuretics generally directly facilitate sodium (Na+) transport, but also indirectly affect renal Ca2+ and Mg2+ handling, i.e., by establishing a prerequisite electrochemical gradient. It is therefore not surprising that substantial alterations in divalent cation handling can be observed following diuretic treatment. The effects of diuretics on renal Ca2+ and Mg2+ handling are reviewed in the context of the present understanding of basal molecular mechanisms of Ca2+ and Mg2+ transport. Acetazolamide, osmotic diuretics, Na+/H+ exchanger (NHE3) inhibitors, and antidiabetic Na+/glucose cotransporter type 2 (SGLT) blocking compounds, target the proximal tubule, where paracellular Ca2+ transport predominates. Loop diuretics and renal outer medullary K+ (ROMK) inhibitors block thick ascending limb transport, a segment with significant paracellular Ca2+ and Mg2+ transport. Thiazides target the distal convoluted tubule; however, their effect on divalent cation transport is not limited to that segment. Finally, potassium-sparing diuretics, which inhibit electrogenic Na+ transport at distal sites, can also affect divalent cation transport. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyze the presence of lithogenic metabolic factors in the blood and urine of patients with osteopenia versus osteoporosis. This is a cross-sectional study including 67 patients who were divided into two groups according to the presence of either osteopenia or osteoporosis as measured by bone densitometry: group 1-40 patients with osteopenia (22 men and 18 women) and group 2-27 patients with osteoporosis (13 men and 14 women). Metabolic studies were performed on the blood and urine; statistical analysis was performed comparing means and conducting linear correlation and multivariate analyses with SPSS. Statistical significance was considered to be p ≤ 0.05. The mean age of patients in group 1 was 52.9 ± 12.8 years versus 50.3 ± 11.4 in group 2; the difference was not statistically significant. In group 2, higher levels of osteocalcin, β-crosslaps, urinary calcium, fasting urine calcium/creatinine, 24 h urine calcium/creatinine and 24 h oxaluria were observed compared to group 1. In the multivariate analysis, only the β-crosslaps and urinary calcium were independently associated with osteoporosis. It would be advisable to determine the urinary calcium levels in patients with osteoporosis since altered levels may necessitate modifying the diagnostic and therapeutic approach to osteoporosis. [ABSTRACT FROM AUTHOR]

Background/Aims: Dietary factors can modify calciuria. We aim to investigate urinary calcium excretion in healthy infants according to their protein. Methods: Secondary data analysis from a randomized clinical trial where healthy term infants were randomized after birth to a higher (HP) or lower (LP) protein content formula that was consumed until age 1 year. A non-randomized group of breastfed (BF) infants was used for reference. Anthropometry, dietary intakes and calciuria (calcium/creatinine ratios) from spot urine samples were assessed at ages 3 and 6 months. At 6 months, the kidney volumes were assessed using ultrasonography, and the serum urea and creatinine levels were determined. Results: BF infants showed the highest calciuria levels, followed by the HP and the LP groups (p < 0.001 for all comparisons). Either protein intakes or formula types modulated the calciuria in linear regression models adjusted for other influenc ing dietary factors. The usual cut-off values classified 37.8% (BF), 16.8% (HP) and 4.9% (LP) of the infants as hypercalciuric. Conclusions: Feeding types during the first months of life affect calciuria, with BF infants presenting the highest levels. We propose new cut-off values, based on feeding types, to prevent the overestimation in hypercalciuria diagnoses among BF infants. [ABSTRACT FROM AUTHOR]

Copyright of Nefrologia is the property of Revista Nefrologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: The objective was to evaluate the effect of hydrochlorothiazide and alendronate on urine calcium and bone mineral density in calcium stone-forming patients. Material and Methods: A prospective, non-randomized, nonobservational comparative study was performed; this study included 111 patients with recurrent calcium stones, divided into 3 groups according to the treatment received. Group 1: 36 patients were treated with alendronate, 70 mg/week; Group 2: 34 patients were treated with alendronate, 70 mg/ week + hydrochlorothiazide, 50 mg/day; Group 3: 41 patients were treated with hydrochlorothiazide, 50 mg/day. All patients received recommendations on diet and fluid intake. Other variables of bone mineral density were studied and analyzed, including bone remodeling markers and urinary calcium before and after 2 years of treatment. The statistical analysis was performed using the SPSS 17.0 program, with a statistical significance of p < 0.05. Results: After 2 years of treatment, a significant difference was observed in the β-crosslaps and a bone mineral density improvement in Group 1, along with a decrease in urinary calcium. In Group 3, a statistically significant difference was found in urinary calcium and fasting calcium/creatinine ratio, as well as an improvement in bone mineral density after 2 years of medical treatment. In Group 2 patients treated with the combination, there was an improvement in bone mineral density and a decrease in the β-crosslaps marker similar to patients in Group 1, and a decrease in urinary calcium similar to those in Group 3. Conclusion: Combined alendronate + hydrochlorothiazide treatment offers the best results along with the improvement in bone mineral density and decrease in urine calcium in patients with recurrent calcium stones. [ABSTRACT FROM AUTHOR]

Aim: This study aimed to evaluate the urinary calcium excretion pattern in preeclampsia and to establish the relation between severity of preeclampsia and urinary calcium excretion Methods: This was a case-control study conducted at Paropakar Maternity and Women’s Hospital, Kathmandu from January to June 2015. There were 88 patients equally divided in each group. 24 hours urine calcium was analyzed by ortho-cresophthalin-complexone method (OCPC) and urinary proteinuria was analyzed bedside by sulphosalicylic acid. Results were analyzed using SPSS 17. P value of < 0.05 was considered as significant. Results: Preeclampsia was found to occur commonly among the nulliparous patients (59%). The patients with MAP with ≥ 110mmHg excreted less calcium in their urine in comparison to the patient with MAP < 110mmHg (73.55mg/24 hrs VS 92.79 mg/24 hr). Daily calciuria was decreased with the increase in proteinuria (91.43 mg, 76.19mg and 54.02mg in 1+, 2+ and 3+ respectively). The 24 hours urine calcium excretion in term preeclamptic patient was significantly reduced in compared to the normotensive term pregnant women (77.92 mg ±48.61mg VS 117.66mg ±69.21 mg, p <0.001). Conclusion: Preeclamptic patients excrete significantly lower amounts of calcium in urine and it may be a marker of the severity of preeclampsia. [ABSTRACT FROM AUTHOR]

Urinary calcium excretion has been reported to be diminished in preeclampsia. The objective of the present study was to determine urinary calcium excretion in pregnant patients with chronic arterial hypertension (CAH) and preeclampsia (PE), and in normotensive patients (N). Forty-four pregnant patients (gestional age, 20-42 weeks; 18 CAH, 17 PE, 9 N) were evaluated for calciuria, proteinuria, plasma uric acid and blood pressure. Patients with PE (82 ± 15.1 mg/24 h) showed significantly lower calciuria (P

Background The incidence of nephrolithiasis during childhood has increased significantly over recent decades. Some studies indicate a rapid rise in adolescents, particularly in African American women. This study serves to identify trends in symptomatic pediatric nephrolithiasis presentations to the emergency department (ED) as a result of increasing incidence and to determine associations between demographic variables at our single-site tertiary pediatric hospital in the Southeast United States. Methods After IRB approval, a review of the data provided by the Pediatric Health Information System, a pediatric database that includes clinical and resource utilization data for 51 of the largest children's hospitals in the nation, yielded 644 pediatric occurrences of nephrolithiasis at single-site emergency departments from 2006 to 2020. The percent change and average percent change in three-year intervals were calculated to establish a trend over time. A chi-square test of independence was performed to assess associations between race, gender, and age groups. Results A total of 780 stone occurrences and associated patient demographic data were reviewed for 644 children (364, 56.52% female) with median age of 183 ± 45.11 months (9-397 months). Of the 644 children, 79 (12.3%) were noted to have recurrent symptomatic nephrolithiasis, contributing to 136/780 stone events. There was a marked increase of 84.4% in confirmed pediatric nephrolithiasis occurrences over 15 years, with an average percent increase of 16.1% every three years. A Chi 2 test of independence was performed between gender and age group (>/< 10yr), gender and race, and race and age group. No expected cell frequencies were less than five. There is no statistically significant relationship between gender and age group, χ 2 (1, N =644) = 3.30, p =0.692. There is no significant association between race (Caucasian vs. non-Caucasian) and age group (>/< 10yr), χ 2 (1, N =644) = 0.393, p =0.531. There is a statistically significant relationship between gender and race (Caucasian vs. non-Caucasian), χ 2 (1, N =644) = 5.28, p =0.021. Caucasian females were more likely to present to our tertiary pediatric hospital's emergency department with nephrolithiasis than Caucasian males or non-Caucasian males or females. Additionally, our data reflected a greater percentage of symptomatic nephrolithiasis presentations occurred in the second decade of life (85.4% vs 14.3%, 552 vs 92 stone events). Conclusion Based on our data, there is a marked increase of 84.4% in pediatric nephrolithiasis occurrences from 2006 to 2020, with a mean increase of 16.1% every three years at our single-site tertiary referral pediatric hospital in the Southeast. Among demographic groups, white adolescent females have an increased risk of developing kidney stones., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Zhang et al.)

Background: Hypercalciuria and hypocitraturia are considered the most important risk factors for urolithiasis. Citrate binds to urinary calcium to form a soluble complex which decreases the availability of ionized calcium (Ca) necessary for calcium oxalate formation and phosphate crystallization. The aims of this study were to assess the Ca fraction in relation to total calciuria, citraturia and urinary pH and to determine whether urinary Ca concentration is a helpful biomarker in metabolic evaluation of children with urolithiasis. Methods: We collected 24-h urine samples from 123 stone-forming children and adolescents with hypocitraturia and from 424 healthy controls. Total calciuria (total calcium, Ca), Ca, pH, citrate, oxalate and Bonn Risk Index (BRI) were assessed and compared between the two groups. Results: Total calciuria and Ca content were higher in stone-formers than in the healthy children. In both stone-formers and controls, Ca content was inversely related to citraturia and urinary pH, whereas the Ca/Ca ratio differed slightly between the groups. A large variability in Ca level was found across individuals in both groups. The BRI increased with increasing calciuria and urine acidity. Conclusions: Compared to controls, stone-formers with hypocitraturia demonstrated a higher urinary Ca concentration, but this was proportional to calciuria. The large individual variability in urinary Ca content limits its practical use in metabolic evaluation of children with urolithiasis. However, the Ca/Citrate ratio may be a useful clinical tool in evaluating children with urolithiasis. [ABSTRACT FROM AUTHOR]

Background: Renal complications in acromegaly include glomerular hyperfiltration, insulin resistance, hypercalciuria and urolithiasis. The aim of this study was to investigate whether urinary calcium (U) excretion is a direct consequence of growth hormone secretion or secondary to hyperfiltration and/or insulin resistance. Methods: We performed a cross-sectional study of 58 patients diagnosed with acromegaly. Demographic data were obtained, serum analysis was performed, including insulin-like growth factor (IGF)-1, and 24-h urine collection, to measure urinary protein excretion, U and phosphate excretion, as well as fractional excretion of sodium and potassium. We also calculated the homeostasis model assessment of insulin resistance (HOMA-IR). Results: Patients were predominantly male (60.3%), and their mean age was 45.9 ± 14 years. Hypercalciuria was present in 24% of patients. Patients with higher HOMA-IR had higher IGF-1 levels, a trend toward higher body mass index and higher U excretion. In univariate analysis, U excretion was associated with HOMA-IR ( r = 0.472, P = 0.001), phosphaturia ( r = 0.457, P = 0.001), IGF-1 ( r = 0.398, P = 0.002) and creatinine clearance ( r = 0.394, P = 0.001). HOMA-IR and phosphaturia were independently associated with U excretion. No independent associations were found between phosphaturia and HOMA-IR or IGF-1. Conclusions: The present study revealed an association between hypercalciuria and insulin resistance in patients with acromegaly. Further studies are required to fully understand the pathogenesis of these abnormalities in patients with acromegaly. [ABSTRACT FROM AUTHOR]

Background: Inhaled corticosteroids have become the first-line medication for treatment of childhood asthma. Possible adverse effects, such as those on bone metabolism and urinary excretion of calcium are in the focus of interest. We investigated the influence of inhaled fluticasone on bone metabolism and renal excretion of calcium, sodium, and potassium in asthmatic children. Methods: Thirty asthmatic patients (mean age 12.24 ± 2.75 years) treated with 200-250 μg/day inhaled fluticasone were enrolled in the study. Prior to the initiation of therapy, as well as 12 weeks after following parameters were measured: serum sodium, potassium, calcium, phosphorus, creatinine, alkaline phosphatase, osteocalcin, intact parathyroid hormone levels, first-spot morning urine calcium/creatinine ratio, sodium/potassium ratio, and daily renal calcium excretion rate. Results: Serum electrolytes, alkaline phosphatase, parathyroid hormone, osteocalcin levels, as well as urinary calcium, sodium, and potassium excretion were within normal ranges. There was no statistical difference between values of those parameters prior and 12 weeks after initiation of the therapy. Conclusions: Treatment with 200-250 μg/day inhaled fluticasone, in asthmatic children aged 9-16, during 12 weeks, did not affect serum osteocalcin level and renal excretion of calcium, sodium, and potassium. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background. Secondary hyperparathyroidism is a common complication of chronic kidney disease (CKD) that is associated with bone disease, cardiovascular disease and death. Pathophysiological factors that maintain secondary hyperparathyroidism in advanced CKD are well-known, but early mechanisms of the disease that can be targeted for its primary prevention are poorly understood. Diuretics are widely used to control volume status and blood pressure in CKD patients but are also known to have important effects on renal calcium handling, which we hypothesized could alter the risk of secondary hyperparathyroidism.Methods. We examined the relationship of diuretic treatment with urinary calcium excretion, parathyroid hormone (PTH) levels and prevalence of secondary hyperparathyroidism (PTH ≥ 65 pg/mL) in a cross-sectional study of 3616 CKD patients in the Chronic Renal Insufficiency Cohort.Results. Compared with no diuretics, treatment with loop diuretics was independently associated with higher adjusted urinary calcium (55.0 versus 39.6 mg/day; P < 0.001), higher adjusted PTH [67.9, 95% confidence interval (CI) 65.2–70.7 pg/mL, versus 52.8, 95% CI 51.1–54.6 pg/mL, P < 0.001] and greater odds of secondary hyperparathyroidism (odds ratio 2.1; 95% CI 1.7–2.6). Thiazide monotherapy was associated with lower calciuria (25.5 versus 39.6 mg/day; P < 0.001) but only modestly lower PTH levels (50.0, 95% CI 47.8–52.3, versus 520.8, 95% CI 51.1–54.6 pg/mL, P = 0.04) compared with no diuretics. However, coadministration of thiazide and loop diuretics was associated with blunted urinary calcium (30.3 versus 55.0 mg/day; P <0.001) and odds of hyperparathyroidism (odds ratio 1.3 versus 2.1; P for interaction = 0.05) compared with loop diuretics alone.Conclusions. Loop diuretic use was associated with greater calciuria, PTH levels and odds of secondary hyperparathyroidism compared to no treatment. These associations were attenuated in patients who were coadministered thiazides. Diuretic choice is a potentially modifiable determinant of secondary hyperparathyroidism in CKD. [ABSTRACT FROM AUTHOR]

The effects of glucose, sorbitol and xylitol ingestion on calciuria, oxaluria and phosphaturia in healthy black and white males on a standardized diet were investigated. After ingestion, they collected urine hourly for 3 h. Glucose decreased phosphaturia in blacks. Sorbitol decreased phosphaturia in both groups and increased oxaluria in whites. Xylitol increased oxaluria in blacks. Decreases in phosphaturia are attributed to penetration by phosphate into cells leading to decreases in phosphatemia and the renal filtered load. We suggest that this mechanism is more sensitive in blacks. We speculate that the increase in oxaluria after sorbitol ingestion occurs via its conversion to glyoxylate and that this pathway may be blocked in blacks. For the increase in oxaluria after xylitol ingestion, it is hypothesized that ketohexokinase and aldolase may be more active in blacks. Our results demonstrate, for the first time, a urinary effect due to sorbitol ingestion and an ethnic dependency of these and other effects. [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated reduced bone mineral density (BMD) and biochemical changes of excessive bone resorption in some patients with idiopathic hypercalciuria (IH). Consequently, bisphosphonates have been successfully employed in research animals and adults with IH and reduced BMD. We evaluated the effect of treatment with bisphosphonates in seven patients ages 10–16 years with persistent IH and reduced BMD. In five children, preceding traditional therapy failed. All children received oral alendronate and one also IV Zoledronic acid for 6–18 (median 9.0, mean 10.7) months. With treatment, BMD Z scores in the lumbar spine improved from −2.0 ± 0.3 to −0.8 ± 0.8 ( p = 0.002) and in the femoral neck from −1.8 ± 0.4 to −0.7 ± 0.9 ( p = 0.01); urine N-telopeptides/creatinine decreased from 372 ± 289 to 72 ± 39 nmol/mmol ( p = 0.05) and calcium/creatinine from 0.29 ± 0.12 to 0.13 ± 0.06 mg/mg ( p = 0.009). Height Z scores, normal at baseline in all, remained unaffected, and no new stones or fractures were documented throughout the treatment period. Serum creatinine, electrolytes, calcium, phosphorus and parathyroid hormone remained normal as well. In summary, in children with IH and decreased BMD, treatment with bisphosphonates normalized urine calcium excretion, eliminated urinary symptoms, and significantly improved reduced BMD. These short-term beneficial effects indicate the need for larger prospective studies on the potential of bisphosphonates to serve as a new tool in treating children with IH and reduced BMD. [ABSTRACT FROM AUTHOR]

Idiopathic hypercalciuria is a defect occurring in 5–10% of the general population and most commonly detected in patients with calcium kidney stones or osteoporosis. Although high-penetrance autosomal dominant inheritance cannot be ruled out, hypercalciuria is probably a polygenic phenomenon. Findings obtained in monogenic disorders characterized by renal calcium stones, and/or hypercalciuria, and/or nephrocalcinosis, have suggested a number of genes as candidate genes in the pathogenesis of idiopathic hypercalciuria, i.e. soluble adenylate cyclase, calcium sensing receptor, vitamin D receptor and 1-alpha hydroxylase, sodium-phosphate co-transporter-2, claudin-16, chloride channel 5, etc. All the genetic findings obtained so far do not support the idea of different types of idiopathic hypercalciuria, i.e. absorptive, renal, and resorptive. On the contrary, they support clinical observations, which suggest idiopathic hypercalciuria as a single disorder characterized by altered calcium transport in the intestine, kidney and bone, due to various different combinations of multiple genetic and dietary players. [ABSTRACT FROM AUTHOR]

Coexpression studies in Xenopus oocytes revealed the ability of the serum- and glucocorticoid-inducible kinase 1 (SGK1) to stimulate the renal epithelial Ca2+ channel TRPV5. SGK1 increases the abundance of the channel protein in the plasma membrane, an effect requiring the participation of the Na+/H+ exchanger regulating factor 2 (NHERF2). The present study was performed to explore the role of SGK1 in the regulation of renal Ca2+ handling in vivo. To this end, TRPV5, calbindin D-28K abundance, and renal Ca2+ excretion were analyzed in gene-targeted mice lacking functional SGK1 ( sgk1 −/− ) and their age- and sex-matched littermates ( sgk1 +/+ ). Immunohistochemistry revealed lower abundance of TRPV5 and calbindin D-28K protein in sgk1 −/− mice than in sgk1 +/+ mice, both fed with control diet. Feeding the mice a Ca2+-deficient diet marked ly increased TRPV5 protein abundance in both genotypes. Renal Ca2+ excretion under control diet was significantly lower in sgk1 −/− than in sgk1 +/+ mice. The Ca2+-deficient diet decreased renal excretion of Ca2+ to the same levels in both phenotypes. Furosemide increased fractional Ca2+ excretion and dissipated the difference between phenotypes. We conclude that lack of SGK1 may lead to decrease in TRPV5 abundance in connecting tubules but does not abrogate TRPV5 regulation. The decrease in abundance of TRPV5 in connecting tubules of sgk1 −/− mice is presumably compensated for by enhanced Ca2+ reabsorption in upstream nephron segments such as the loop of Henle, which may indirectly result from impaired SGK1-dependent Na+ reabsorption in the aldosterone-sensitive distal part of the nephron, salt loss, and enhanced Na+ (and Ca2+) reabsorption in those upstream nephron segments. [ABSTRACT FROM AUTHOR]

Abstract: Objective: The aim of this study was to compare calciuria of preeclamptic cases to normotensive controls among pregnant women hospitalized in the French West Indies obstetrics department. Study design: This case-control study included 47 preeclamptic women and 50 controls. The main outcome was 24h urinary calcium excretion rate. Serum levels of creatinine, calcium and uric acid were also analyzed. A logistic regression analysis has been performed to investigate the relationship between hypocalciuria and preeclampsia after having taken into account prognostic preeclampsia factors and pertinent clinical criteria. Results: Women with preeclampsia had significantly lower calciuria than normotensive patients (1.5mmol/24h±1.0 versus 6.0mmol/24h±4.2, p =0.0001). After taking into account gestational age at hospitalization, body mass index and nulliparity, hypocalciuria was significantly associated with preeclampsia (ORa=21.74; 95% CI, 6.9–66.7). The diagnosis value of a calciuria less than 2.1mmol/24h is interesting because of its negative predictive value (97%), but its positive predictive value is weak (42%). Conclusion: In our population, preeclamptic women had a calciuria significantly lower than controls. [Copyright &y& Elsevier]