[Calcium supply of adolescent girls and sucrose-lactose imbalance in nutrition].

Ensuring calcium homeostasis is a complex metabolic process. Its impairment, especially in childhood and adolescence, is manifested by numerous changes in the functioning of most organism systems, which are difficult to restore in later periods of life. The goal of this research was to study the characteristics of calcium and disaccharide consumption by adolescent girls and to identify the physiological and biochemical mechanisms of the influence of sucrose-lactose imbalance on calcium supply. Material and methods. A multicenter cross-sectional study was conducted. In this study, teen girls aged 11-14 years without an established diagnosis of lactase insufficiency, living in urban areas, took part on a voluntary basis in the autumn period (n=136, of which 40 were Adyghes, 45 Chechens, other nationalities, mainly Russian - 51). Three-day diets were analyzed, physiological manifestations of calcium deficiency and taste sensitivity to sucrose were evaluated, the CFRt indices (sum of carious, filled and removed permanent teeth) were calculated, and calciuria was studied according to the Sulkovich test in the morning portion of urine. Results. It has been established that the consumption of milk and dairy products by adolescents does not meet physiological standards, which leads to the 2.2 fold decrease in their contribution to calcium provision and to the risk of insufficient milk calcium consumption (RIC Camilk). In the nutrient status of adolescents, regardless of nationality and region of residence, the syndrome of sucrose-lactose imbalance (SLI) was revealed: the 1.4 fold excess of sucrose consumption and 2.1 fold decrease in lactose consumption compared with optimal values. For further analysis, the children were divided into groups, variable in the combination of RIC Camilk and SLI of varying severity: group 1LL - low RIC Camilk and low SLI; group 2LM - low RIC Camilk and moderate SLI, group 3MM - moderate RIC Camilk and moderate SLI; group 4MH - moderate RIC Camilk and high SLI, and group 5HH - high RIC Camilk and high SLI. The analysis of the data showed that higher levels of SLI (groups 2LM and 4MH) at the same levels of RIC Camilk (groups 1LL and 3MM) reduce calcium bioavailability, impair calcium metabolism and increase the prevalence and severity of physiological manifestations of calcium insufficiency by 1.5 and 1.4 fold, and dental diseases estimated using the CFRt index - by 1.2 and 1.6 fold. The prevalence of low taste sensitivity to sucrose in 5HH group was 1.4 fold higher compared to 4MH group. Against the background of excessive consumption of added sugars, calciuria didn't significantly differ in groups with different levels of calcium intake. Conclusion. Based on the assessment of nutrition, teen girls showed SLI syndrome and high RIC Camilk. SLI reduces calcium availability, increasing the prevalence of calcium insufficiency symptoms in adolescent girls with moderate and high RIC Camilk.

Intermittent cholecalciferol supplementation in children and teenagers followed in pediatric nephrology: data from a prospective single-center single-arm open trial.

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.

Assessment of mineral and bone biomarkers highlights a high frequency of hypercalciuria in asymptomatic healthy teenagers.

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, ß-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, ß-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.

[Calcium response to vitamin D supplementation]. / Respuesta de la calciuria a suplementos de vitamina D.

Several studies show the importance of serum vitamin D sufficient levels to prevent multiple chronic diseases. However, vitamin D supplementation and its effects on urine calcium excretion remain controversial. The objective of this prospective and interventional study was to evaluate urine calcium excretion in women with normal calciuria or hypercalciuria, once serum vitamin D sufficiency was achieved. We studied 63 women with idiopathic hypercalciuria, (9 with renal lithiasis) and 50 normocalciuric women. Both groups had serum vitamin D levels low (deficiency or insufficiency). Baseline urine calcium excretion was measured before being supplemented with vitamin D2 or D3 weekly or vitamin D3 100.000 IU monthly. Once serum vitamin D levels were corrected achieving at least 30 ng/ml, a second urine calcium excretion was obtained. Although in the whole sample we did not observe significant changes in urine calcium excretion according to the way of supplementation, some of those with weekly supplementation had significant higher urine calcium excretion, 19% (n = 12) of hypercalciuric women and 12% (n = 6) of the normocalciuric group. Monthly doses, also showed higher urine calcium excretion in 40% of hypercalciuric women (n = 4/10) and in 44% (n = 4/9) of the renal lithiasis hypercalciuric patients. In conclusion, different ways of vitamin D supplementation and adequate serum levels are safe in most patients, although it should be taken into account a subgroup, mainly with monthly loading doses, that could increase the calciuria significantly eventually rising renal lithiasis risk or bone mass loss, if genetically predisposed.

Effect of diuretics on renal tubular transport of calcium and magnesium.

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 cation-permeable 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.

Association among prematurity (<30 weeks' gestational age), blood pressure, urinary albumin, calcium, and phosphate in early childhood.

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.

Influence of Feeding Types during the First Months of Life on Calciuria Levels in Healthy Infants: A Secondary Analysis from a Randomized Clinical Trial.

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 influencing 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.

The Urine Calcium/Creatinine Ratio and Uricemia during Hyponatremia of Different Origins: Clinical Implications.

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).

Normonatremic Transient Renal Salt Wasting (TRSW) Is Not Rare in a Department of Internal Medicine.

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.

Bone mineral density and growth changes in patients with distal renal tubular acidosis after two-years treatment with a new alkalizing drug (ADV7103).

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<0.005). There was an increase>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.

Incidence of Emergency Department Presentations of Symptomatic Stone Disease in Pediatric Patients: A Southeastern Study.

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 Chi2 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, χ2 (1, N=644) = 3.30, p=0.692. There is no significant association between race (Caucasian vs. non-Caucasian) and age group (>/< 10yr), χ2 (1, N=644) = 0.393, p=0.531. There is a statistically significant relationship between gender and race (Caucasian vs. non-Caucasian), χ2 (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.

Effect of parathyroidectomy on renal stone recurrence.

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.

Safety of megadose of vitamin D in patients with nephrolithiasis.

OBJECTIVE: This article describes two patients with renal lithiasis who received a megadose of 25-hydroxy vitamin D (25[OH]D) and had a good outcome. METHODS: The first case reports a 74-year-old man with a long-term history of renal lithiasis and about four episodes of renal crisis. He was treated once with extracorporeal shock wave lithotripsy. He also had a history of dyslipidemia, myocardial infarction, and stroke. Laboratory tests demonstrated 25(OH)D of 28 ng/mL (normal range (nr): >30 ng/mL), normal lipid levels, creatinine of 1.1 mg/dL, and homocysteine of 26.6 mcmol/L (nr: 5-15 mcmol/L); parathyroid hormone (PTH) was high at 67.3 pg/mL (nr: 10-65 pg/mL), serum total calcium was 8.6 mg/dL, 24-h urinary calcium was 139 mg/d (normal range 100-300 mg/d), and urinary sediment was normal. He received 50 000 IU per week of vitamin D for 3 mo, and 25(OH)D increased to 36.6 ng/mL. Urinary calcium was 142 mg/d, PTH was 46.7 pg/mL, and serum calcium was 9.6 mg/dL. No renal crisis was perceived. He asked for an alternative form of medication since he usually would forget to take drugs. Vitamin D in a single dose of 600 000 IU intramuscular was prescribed. He was asked to increase water intake to 2 to 3 L/d. After 3 mo his 25(OH)D was 75.0 ng/mL, serum calcium was 9.2 mg/dL, urinary calcium was 148 mg/d, and PTH was 38.7 pg/mL. He had no episodes of lithiasis renal crisis. Folic acid and methylcobalamin were added, and homocysteine normalized. At follow-up 3 y later, the patient was asymptomatic, cardiologic evaluation was stable without any other renal lithiasis crises, 25(OH)D continued to be normal at 62 ng/mL, and he received a megadose of vitamin D every 6 mo. Renal ultrasound revealed only microlithiasis. The second case reports a 52-year-old man with a long-term history of renal lithiasis experienced since he was 30 y old, with three renal crisis episodes. He was treated with an extracorporeal shock wave three times. Laboratory tests demonstrated 25(OH)D 18 ng/mL, normal biochemistry, total serum calcium of 10.2 mg/dL, 24-h urinary calcium of 154 mg/d, and normal urinary sediment. He received 50 000 IU per week of 25(OH)D for 3 mo, and 25(OH)D increased to 40.3 ng/mL. Urinary calcium was 167 mg/d, PTH was 35.3 pg/mL, and serum calcium was 10.1 mg/dL. No renal crisis was perceived. He asked for an alternative form of medication, and vitamin D in a single dose of 600 000 IU intramuscular was prescribed. He was asked to increase water intake to 2 to 3 L/d. After 3 mo, his 25(OH)D was 82.0 ng/mL, serum calcium was 9.6 mg/dL, urinary calcium was 175 mg/d, and PTH was 35.3 pg/mL. The renal ultrasound was unchanged. He had no episodes of lithiasis renal crisis. At follow-up 4 y later, the patient was asymptomatic without any other renal lithiasis crises, a renal ultrasound revealed a reduction of calculi size to microlithiasis, 25(OH)D continues normal, and he received a megadose of this vitamin every 4 mo. CONCLUSION: To the best of our knowledge, this is the first description of a megadose of vitamin D used in patients with nephrolithiasis. Furthermore, this shows the safety of this strategy in patients without hypercalciuria.

Children with Intestinal Failure Maintain Their Renal Function on Long-Term Parenteral Nutrition.

BACKGROUND: Long-term parenteral nutrition (PN) has been associated with renal complications, including hypercalciuria, nephrocalcinosis, proteinuria and reduced glomerular filtration rate (GFR). Pediatric data are scarce and mostly short-term. Our study aimed to evaluate renal complications in children with intestinal failure (IF) receiving long-term PN. METHODS: A cross-sectional study was performed in a tertiary pediatric IF clinic of patients receiving home-PN treatment for more than 1 year. Data regarding medical background, anthropometrics, laboratory investigations and abdominal sonography were retrieved. RESULTS: Complete data were available for 15 children (67% males), with a median age of 6 (range 1.5-15) years and a median (IQR) PN duration of 4 (1.5-6) years. Low-grade proteinuria was identified in 61% and microalbuminuria in 30% of the cohort. Hypercalciuria and hyperoxaluria were present in 50% and 46%, respectively. One patient had nephrocalcinosis. The estimated GFR was normal in all but one patient who had pre-existing kidney disease. CONCLUSIONS: Pediatric IF patients can present with preserved kidney function after years of PN treatment. Despite the high prevalence of hypercalciuria, nephrocalcinosis was not common. Base line and long-term monitoring of various aspects of renal function would be essential to characterize the effects of prolonged PN on kidney functions in pediatric patients.

Effects of diuretics furosemide and hydrochlorothiazide on CKD-MBD: A prospective randomized study.

Although diuretics are often prescribed to control fluid overload, they can change Chronic kidney disease-mineral and bone disorder (CKD-MBD) parameters. Previous studies have shown an association between diuretic prescription and changes in both calciuria and parathormone levels. However, the causal relationship could not be confirmed. In addition, the effects of diuretics on bone mineral density and turnover markers are yet to be established. To evaluate the effects of diuretics on CKD-MBD, we have performed a prospective randomized trial comparing hydrochlorothiazide with furosemide in a stage 3CKD population followed for 1 year. Furosemide increased bone remodeling and parathormone levels, whereas hydrochlorothiazide attenuated parathyroid hormone rise and decreased bone turnover markers.

Distar Renal Tubular Acidosis (dRTA): Epidemiological, diagnostics, clinical follow-up and therapeutical issues. Nephrologists cohort survey outcome.

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.

Distar Renal Tubular Acidosis (dRTA): Epidemiological, diagnostics, clinical follow-up and therapeutical issues. Nephrologists cohort survey outcome. / Acidosis tubular renal distal (ATRd): aspectos epidemiológicos, diagnósticos, de seguimiento clínico y terapéuticos. Resultados de una encuesta a un colectivo de nefrólogos.

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.

Regulation of urinary calcium excretion by vasopressin.

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.

A long-term study of the effects of SLC12A1 homozygous mutation (g.62382825G>A, p.Pro372Leu) in Japanese Black cattle.

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.