Search Results (23)

Background/Objectives: Pediatric osteoporosis is a multifactorial condition characterized by impaired bone mineralization and increased fracture risk, particularly vertebral compression fractures. This study aims to evaluate the diverse etiology, diagnostic challenges, and treatment options for pediatric osteoporosis in a cohort of affected children. Methods: We reviewed eleven pediatric patients (aged 5–16 years) diagnosed with vertebral fractures and osteoporosis, who were hospitalized between 2020 and 2024 at the Department of Endocrinology and Metabolic Diseases at PMMH-RI in Lodz. Clinical evaluation included medical history, physical examination, biochemical markers of bone metabolism, and imaging techniques such as dual-energy X-ray absorptiometry (DXA) to determine underlying causes of bone fragility. Results: The cohort presented a broad etiological spectrum, including seven patients with genetic disorders (e.g., mutations in COL1A1, LRP5, SGMS2, and ALPL genes) and secondary osteoporosis due to chronic diseases requiring prolonged glucocorticoid therapy (two patients with Duchenne muscular dystrophy (DMD), one patient with Crohn’s disease) or endocrinological disorders (one patient with Cushing disease). Vertebral fractures were confirmed in all patients, with back pain as the predominant symptom. Low bone mass (BMD Z-score < −2.0) was observed in eight individuals; in others, clinical signs of skeletal fragility were present despite Z-scores above this threshold. Mild biochemical abnormalities included hypercalciuria (3/11 cases) and vitamin D deficiency (6/11 cases). Height adjustment improved BMD interpretation in short-stature patients. Most children received bisphosphonate therapy, supplemented with calcium and vitamin D. In two patients, bisphosphonates were not used due to lack of parental consent or underlying conditions in which such treatment is not recommended. Conclusions: Pediatric osteoporosis requires a multidisciplinary diagnostic and therapeutic approach, integrating clinical, biochemical, and genetic factors. It is a heterogeneous and often underrecognized condition, with vertebral fractures frequently serving as its earliest sign—even in the absence of overt symptoms or low bone mass. This underscores the need for clinical vigilance, as significant skeletal fragility may occur despite normal BMD values. Importantly, pediatric osteoporosis may also impact the attainment of peak bone mass and ultimately affect final adult height. Early diagnosis through thorough assessment, including height-adjusted DXA, and a multidisciplinary approach are essential to ensure timely management and prevent long-term complications. Full article

Background: Idiopathic hypercalciuria (IH) is the most common genetic metabolic disorder in patients with urinary stones and is usually treated with thiazide-type diuretics. However, direct evidence comparing low-dose indapamide and hydrochlorothiazide is scarce. This study aimed to compare their safety, efficacy and adherence in patients with IH. Methods: In this randomized prospective trial, a total of 101 patients with IH were recruited at Son Espases University Hospital (2020–2023), assigned to receive indapamide 1.5 mg/day (n = 53) or hydrochlorothiazide 25 mg/day (n = 48), and followed for 18 months. Adverse events, biochemical parameters and therapeutic adherence were evaluated. Results: A total of 90.24% patients on indapamide and 85.71% on hydrochlorothiazide showed normal calciuria (p = 0.53). Both treatments increased serum urate (p = 0.62). Indapamide significantly reduced β-crosslaps (p < 0.05), suggesting bone protection. No significant differences were found in citraturia, uricosuria, phosphaturia, magnesiuria, magnesemia, natremia, or kalemia. Indapamide caused more mild adverse events, lowering adherence, while hydrochlorothiazide caused the only severe adverse effect—moderate hypokalemia. No differences in kidney stone recurrence were observed (p = 0.82). Conclusions: This is the first paper elucidating low-dose indapamide and hydrochlorothiazide efficacy and safety for the treatment of IH. No significant differences were observed between the two drugs in terms of adverse events or treatment adherence. A longer follow-up is needed to assess kidney stone recurrence. Full article

Background: Abnormal sodium-dependent hexose reabsorption in the proximal tubule, accompanied by a functional decrease in sodium and water reabsorption under conditions of increased volemia, may be attributed to a dysfunction of primary transporters related to a genetic defect in the Na,K-ATPase gamma subunit. Methods: We examined two sisters, aged 6 and 8 years, who presented with hypercalciuria, glucosuria, fructosuria, galactosuria, and atypical proteinuria. Primary diabetes, galactosemia, and fructosemia were excluded, suggesting a defect in cellular hexose transport in the proximal tubule. We conducted tests on the family members to assess the impact of gradually increasing volemia, using a water-loading test, on tubular H⁺ transport and urinary excretion of calcium, citrate, endothelin-1 (ET-1), and atypical proteins. Whole-exome sequencing was performed in the affected patients to identify the genetic basis of this phenotype. Results: Extended investigations revealed a complex defect in tubular H⁺ transport, calcium and citrate handling, and atypical proteinuria, resulting from water load-driven overproduction of endothelin-1 (ET-1). Genetic analysis identified a heterozygous pathogenic variant, c.80G>A, p.(Arg27His), in the FXYD2 gene, which encodes the gamma subunit of sodium/potassium-transporting ATPase. Conclusions: Our findings provide evidence that a defect in FXYD2 (splice form a) leads to functional impairment of proximal tubular hexose reabsorption. This is the first report on the metabolic consequences of a pathogenic FXYD2 variant affecting the gamma subunit of sodium/potassium-transporting ATPase in humans. The genotype–phenotype correlation in two siblings with a sodium-dependent defect in fructose, galactose, and glucose renal reabsorption allowed us to characterize a disease with a distinct clinical course and biochemical profile, not previously reported in the medical literature or genetic databases. Analysis of this condition was crucial for the early introduction of reno-protective treatment aimed at slowing the progression of nephropathy and for risk assessment in family members, which was essential for genetic counseling. Full article

Background/Objectives: Epidemiological data on vitamin D status revealed that, despite various dosage and durations of supplementation, the effectiveness often fails to achieve optimal outcomes. The need for higher doses than previously recommended was suggested, but several modifying factors should be considered, including the level of deficiency, and BMI. The objectives of this post hoc evaluation are to characterize treatment effectiveness based on the applied dose, duration and BMI; and to assess the safety aspects associated with rapid repletion of vitamin D. Methods: Vitamin D deficient subjects selected in the post-hoc analysis: seventy patients included from a combined loading-maintenance supplementation (300,000 IU followed by 60,000 IU) protocol and 62 deficient subjects who received a low-dose maintenance (1000 IU/day) therapy. The risk of overload and the incidence of hypercalciuria and hypercalcemia resulting from loading or post-loading maintenance were investigated. Results: The moderate–fast-loading schedule of 60,000 IU per week for 5 weeks, effectively achieves the target in 25(OH)D levels over 30 ng/mL for all deficient subjects, regardless of their BMI. Slower loading with lower weekly doses confirms the safety of supplementation, but the effectiveness is dependent on the subjects’ BMI; overweight and obese patients require higher doses to reach the same vitamin D levels. No difference in safety parameters observed compared to low-dose therapies. Conclusions: The loading treatment involving a total dose of 300,000 IU administered over 5 or 10 weeks is effective for repletion, does not lead to 25(OH)D overload, and poses no additional risks of hypercalcemia or hypercalciuria. Furthermore, there are no safety concerns regarding changes in bone resorption markers. A combination of the loading treatment with a subsequent maintenance dose of 2000 IU daily is adequate to achieve the target vitamin D levels. Full article

Background and objectives: Nephrocalcinosis (NC) is a common condition characterized by the deposition of calcium salts in the kidneys of very preterm infants due to tubular immaturity, intensive treatment and nutritional supplements. However, optimal vitamin D supplementation remains unclear. In most patients, NC spontaneously resolves within the first year of life, but long-term kidney function data are lacking. The aim was to study nephrocalcinosis in very preterm infants, assess risk factors and evaluate vitamin D’s impact during the first month with a 2-year follow-up. Material and Methods: This was a prospective observational study conducted over a 3-year period in infants with a gestational age of less than 32 weeks. The patients’ data were compared between the NC and control groups based on kidney ultrasound results at discharge. In the first month, the mean vitamin D intake from all sources as well as biochemical markers of calcium metabolism were collected. Patients diagnosed with NC were referred to a pediatric nephrologist after discharge. Results: NC was found in 35% of a cohort of 160 infants, more common in those with a gestational age <28 weeks. Risk factors were associated with higher morbidity and necessary treatment. At 28 days, serum 25-hydroxy vitamin D levels differed between NC and control groups (p < 0.05). The NC group with GA ≥ 28 weeks had higher vitamin D intake (p < 0.05), hypercalciuria and calcium/creatinine ratio (p < 0.01) and lower parathyroid hormone levels (p < 0.05). Follow-up showed resolution in 70% at 12 months and 90% at 24 months. Conclusions: The prevalence of NC in very preterm infants is significant, associated with lower maturity and higher morbidity. Careful vitamin D supplementation and biochemical monitoring of Ca metabolism from the first month of life should support bone health and limit the risk of nephrocalcinosis. Due to the high incidence of NC in very preterm infants, long-term follow-up is essential. Full article

Dietary factors may be implicated in the formation of kidney stones and should be closely monitored. To achieve this aim, patients are routinely assessed by means of generic dietary recall, a tool widely used by authors in a range of extensive patient populations to record food intake; the findings obtained, however, may be skewed due to dietary variations and underestimation of the effect of food additives. Fifty Frequent Kidney Stone Formers (FKSFs, mean age: 54.3 ± 13.9 years) with normal kidney function, absence of comorbidities, and reliable compliance were selected from a total of 68 patients’ resident in Sardinia, an Italian island where genetic admixtures have been relatively rare for generations. The study, conducted from 1 January 2020 to 31 December 2023, was aimed at assessing nutritional values based on the meticulous recording of food quantities, quality, and potential modifications related to food preparation. Patients were selected during an initial clinical check-up and all efforts made to ensure they were capable of reliably recording all food and drinks consumed. A seven-day food diary was provided in which food and drink intake and their impact on 24 h urine output was recorded. The following parameters were measured in both foods and urine output: citrates, oxalates, calcium, phosphorous, uric acid, proteins and nitrogen compounds, magnesium, sulfates, potassium, carbohydrates, free fatty acids. Study outcomes established the presence of hypocitraturia, hyperoxaluria, hypercalciuria, and moderately high levels of nitrogen compounds. Univariate analysis followed by multivariate analysis for further confirmation were performed and the following observations made. Citrate intake correlated with citraturia but did not promote oxaluria; calcium intake promoted onset of sulfaturia, azoturia, and ammoniuria, whilst magnesium correlated with magnesiuria but not with oxaluria, calciuria, phosphaturia, and azoturia; sulfate intake elicited onset of azoturia but not kaliuresis; potassium intake promoted oxaluria and protein intake resulted in onset of ammoniuria and azoturia. (A) The chemical composition of urine based on dietary intake is hard to predict without taking into account the presence of dietary and urinary interferents; (B) the geographic isolation of patients studied underlines the importance of epigenetics in maintaining a traditional dietary heritage. (C) Moreover, the widespread use of food additives should consistently be taken into account to ensure a correct diagnosis of FKSF and set up a valid treatment plan. Full article

Background: Adults who have incomplete distal renal tubular acidosis (dRTA) may present with recurrent urolithiasis due to metabolic acidosis, leading to bone resorption, which in turn causes hypercalciuria and urine alkalinization (pH > 6.0). Oral potassium citrate is the most commonly used treatment for dRTA, but some patients cannot tolerate this treatment. The objective of this single-arm study was to evaluate the effect of phytate, an inhibitor of bone resorption, on calciuria of patients with incomplete dRTA. Methods: The calciuria levels of 16 patients who had incomplete dRTA with urolithiasis and could not tolerate potassium citrate treatment were recorded before (baseline) and after 6 months of treatment with oral calcium magnesium phytate (380 mg every 12 h). There were no dietary modifications or other treatments. Results: The baseline calciuria was 317 ± 81 mg/24 h and the level after 6 months was 221 ± 38 mg/24 h (p < 0.005). Conclusions: Our results suggest that calcium magnesium phytate should be considered as an alternative or adjunctive treatment for hypercalciuria in patients with incomplete dRTA. Full article

Dent disease-1 (DD-1) is a rare X-linked tubular disorder characterized by low-molecular-weight proteinuria (LMWP), hypercalciuria, nephrolithiasis and nephrocalcinosis. This disease is caused by inactivating mutations in the CLCN5 gene which encodes the voltage-gated ClC-5 chloride/proton antiporter. Currently, the treatment of DD-1 is only supportive and focused on delaying the progression of the disease. Here, we generated and characterized a Clcn5 knock-in mouse model that carries a pathogenic CLCN5 variant, c. 1566_1568delTGT; p.Val523del, which has been previously detected in several DD-1 unrelated patients, and presents the main clinical manifestations of DD-1 such as high levels of urinary b2-microglobulin, phosphate and calcium. Mutation p.Val523del causes partial ClC-5 retention in the endoplasmic reticulum. Additionally, we assessed the ability of sodium 4-phenylbutyrate, a small chemical chaperone, to ameliorate DD-1 symptoms in this mouse model. The proposed model would be of significant value in the investigation of the fundamental pathological processes underlying DD-1 and in the development of effective therapeutic strategies for this rare condition. Full article

Kidney stones are becoming increasingly common, affecting up to 10% of adults. A small percentage are of monogenic origin, such as Dent’s disease (DD). DD is a syndrome that causes low-molecular-weight proteinuria, hypercalciuria, nephrolithiasis, and nephrocalcinosis. It is X-linked, and most patients have mutations in the CLCN5 gene. We performed a review of the literature and evaluated the case series (n = 6) of a single center in Spain, reviewing the natural evolution of kidney stones, clinical implications, laboratory analyses, radiological development, and treatment. All patients had a genetically confirmed diagnosis, with the CLCN5 mutation being the most frequent (66%). All patients had proteinuria and albuminuria, while only two and three presented hypercalciuria and phosphate abnormalities, respectively. Only one patient did not develop lithiasis, with most (60%) requiring extracorporeal shock wave lithotripsy or surgery during follow-up. Most of the patients are under nephrological follow-up, and two have either received a renal transplant or are awaiting one. The management of these patients is similar to that with lithiasis of non-monogenic origin, with the difference that early genetic diagnosis can help avoid unnecessary treatments, genetic counseling can be provided, and some monogenic kidney stones may benefit from targeted treatments. Full article

In calcium nephrolithiasis (CaNL), most calcium kidney stones are identified as calcium oxalate (CaOx) with variable amounts of calcium phosphate (CaP), where CaP is found as the core component. The nucleation of CaP could be the first step of CaP+CaOx (mixed) stone formation. High urinary supersaturation of CaP due to hypercalciuria and an elevated urine pH have been described as the two main factors in the nucleation of CaP crystals. Our previous in vivo findings (in mice) show that transient receptor potential canonical type 3 (TRPC3)-mediated Ca²⁺ entry triggers a transepithelial Ca²⁺ flux to regulate proximal tubular (PT) luminal [Ca²⁺], and TRPC3-knockout (KO; -/-) mice exhibited moderate hypercalciuria and microcrystal formation at the loop of Henle (LOH). Therefore, we utilized TRPC3 KO mice and exposed them to both hypercalciuric [2% calcium gluconate (CaG) treatment] and alkalineuric conditions [0.08% acetazolamide (ACZ) treatment] to generate a CaNL phenotype. Our results revealed a significant CaP and mixed crystal formation in those treated KO mice (KOT) compared to their WT counterparts (WTT). Importantly, prolonged exposure to CaG and ACZ resulted in a further increase in crystal size for both treated groups (WTT and KOT), but the KOT mice crystal sizes were markedly larger. Moreover, kidney tissue sections of the KOT mice displayed a greater CaP and mixed microcrystal formation than the kidney sections of the WTT group, specifically in the outer and inner medullary and calyceal region; thus, a higher degree of calcifications and mixed calcium lithiasis in the kidneys of the KOT group was displayed. In our effort to find the Ca²⁺ signaling pathophysiology of PT cells, we found that PT cells from both treated groups (WTT and KOT) elicited a larger Ca²⁺ entry compared to the WT counterparts because of significant inhibition by the store-operated Ca²⁺ entry (SOCE) inhibitor, Pyr6. In the presence of both SOCE (Pyr6) and ROCE (receptor-operated Ca²⁺ entry) inhibitors (Pyr10), Ca²⁺ entry by WTT cells was moderately inhibited, suggesting that the Ca²⁺ and pH levels exerted sensitivity changes in response to ROCE and SOCE. An assessment of the gene expression profiles in the PT cells of WTT and KOT mice revealed a safeguarding effect of TRPC3 against detrimental processes (calcification, fibrosis, inflammation, and apoptosis) in the presence of higher pH and hypercalciuric conditions in mice. Together, these findings show that compromise in both the ROCE and SOCE mechanisms in the absence of TRPC3 under hypercalciuric plus higher tubular pH conditions results in higher CaP and mixed crystal formation and that TRPC3 is protective against those adverse effects. Full article

Cystic fibrosis (CF) is a monogenic disease with different types of mutations that mainly affect the respiratory-digestive system. Calcium (Ca), phosphorus (P), and vitamin D (Vit-D) are essential nutrients for maintaining adequate growth and development, as well as key components in crucial metabolic pathways. Proper diagnosis, treatment, and response are decisive components of precision medicine. Therefore, we conducted a cross-sectional study to evaluate Ca, P, and Vit-D levels along with health and nutritional indicators, regarding their non-skeletal functions, in a series of CF patients. Anthropometric and clinical evaluation, biochemical analysis, dietary survey, and respiratory and pancreatic status were performed. Even though the results showed that all patients had normal dietary and serum Ca levels, 47% of patients had deficient Vit-D intake, 53% of patients had hypovitaminosis D, 35% had insufficient Vit-D levels, 18% had hypophosphatemia, 76% had elevated alkaline phosphate levels, 29% had hypercalciuria, and 65% had hyperphosphaturia. There were no significant differences between homozygous and compound heterozygous patients. Ca, P, and Vit-D levels were associated with body mass index; body composition; physical activity; diet; growth hormones; and the immune, liver, and kidney systems. We suggest a periodically evaluation of Ca and P losses. Full article

Idiopathic infantile hypercalcemia (IIH) is a rare genetic disease, also called hypersensitivity to vitamin D3. The molecular heterogeneity allows for the differentiation between the two forms; IIH type 1 caused by CYP24A1 genetic variants and IIH type 2 associated with SLC34A1 mutations. The affected individuals express a variety of symptoms: hypercalcemia, hypercalciuria, suppressed intact parathormone levels (PTH), nephrocalcinosis, elevated levels of serum 1,25 (OH)2-vitamin D3 or inappropriately normal levels, and kidney phosphate wasting. The present paper describes three cases of IIH with heterozygous mutations in SLC34A1 and CYP24A1 genes, respectively. The genetic diagnosis is of paramount importance for proper treatment and the prediction of long-term outcomes. Full article

This study examined the profile of patients and the impact of diet on the risk of brushite stone formation under controlled, standardized conditions. Sixty-five patients with brushite nephrolithiasis were enrolled in the study. Metabolic, dietary, and 24 h urinary parameters were collected under the habitual, self-selected diet of the patients and the balanced mixed, standardized diet. The [¹³C₂]oxalate absorption, ammonium chloride, and calcium loading tests were conducted. All patients had at least one abnormality on the usual diet, with hypercalciuria (84.6%), increased urine pH (61.5%), and hyperphosphaturia (43.1%) being the most common. Absorptive hypercalciuria was present in 32.1% and hyperabsorption of oxalate in 41.2%, while distal renal tubular acidosis (dRTA) was noted in 50% of brushite stone formers. The relative supersaturation of brushite did not differ between patients with and without dRTA. Among all recent brushite-containing calculi, 61.5% were mixed with calcium oxalate and/or carbonate apatite. The relative supersaturation of brushite, apatite, and calcium oxalate decreased significantly under the balanced diet, mainly due to the significant decline in urinary calcium, phosphate, and oxalate excretion. Dietary intervention was shown to be effective and should be an integral part of the treatment of brushite stone disease. Further research on the role of dRTA in brushite stone formation is needed. Full article

This article will discuss the consequences of chronic hyponatremia. In conditions such as cancer, heart failure, liver cirrhosis, or chronic kidney disease, the presence and magnitude of hypotonic hyponatremia are considered to reflect the severity of the underlying disease and are associated with increased morbidity as well as mortality. Hyponatremia can be acute (<48 h) or chronic (>2–3 days). Chronic hyponatremia is associated with attention deficit, dizziness, tiredness, gait disturbance, falls, sarcopenia, bone fractures, osteoporosis, hypercalciuria (in the syndrome of inappropriate antidiuresis—SIADH), and kidney stones. In vitro studies have shown that cells grown in a low concentration of extracellular sodium have a greater proliferation rate and motility. Patients with chronic hyponatremia are more likely to develop cancer. We will not review the clinical consequences of respiratory arrest and osmotic demyelination syndrome (ODS) of the too-late or excessive treatment of hyponatremia. Full article

Introduction. Primary hyperparathyroidism (PHPT) is a condition characterized by disorders of calcium–phosphate metabolism and bone metabolism caused by pathological overproduction of parathyroid hormone (PTH). The diagnosis of overt PHPT is based on the presence of clinical symptoms and laboratory abnormalities typical of this condition: hypercalcemia, hypercalciuria and elevated iPTH levels. Imaging studies are not used for diagnostic purposes; they are performed to localize the parathyroid glands prior to potential surgical treatment. Technetium 99 m sestamibi scintigraphy (Tc99 m-MIBI) is the gold standard in the assessment of pathologically altered parathyroid glands. Other diagnostic options include cervical ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET). Parathyroid biopsy (P-FNAB) with iPTH washout concentration (iPTH-WC) assessment is still an underestimated method of preoperative parathyroid gland localization. Few studies have reported the utility of US-guided P-FNAB in preoperative assessment of parathyroid lesions. The aim of the study was to present our experience with 143 P-FNAB with iPTH-WC assessment. Material and methods. Laboratory results, US findings, P-FNAB complications and comparison with other imaging techniques were described and analyzed. Results. In 133 (93.0) patients, iPTH washout-to-serum ratio exceeded threshold level 0.5 and were classified as positive results. Median iPTH-WC in this group was 16,856 pg/mL, and the iPTH-WC to serum iPTH ratio was 158. There was no correlation between iPTH-WC and serum PTH, serum calcium, parathyroid gland volume and shape index. In the group of 46 operated patients, 44 demonstrated positive iPTH-WC results, which corresponds to a sensitivity of 95.6%. In Tc99-MIBI, radiotracer retention was found in 17 cases (in 24 MIBI performed), which corresponds to a sensitivity of 52.2%. P-FNAB did not cause any major side effects −92.5% of all patients had no or mild adverse events after this procedure. Conclusions. P-FNAB with iPTH-WC is a reliable method in parathyroid adenoma localization during PHPT. Its sensitivity for diagnosis of PHPT is much higher than that of Tc99-MIBI, and in some situations, P-FNAB with iPTH-WC may even replace that method. Furthermore, cost-effectiveness of iPTH-WC is at least similar to that of Tc99-MIBI. Complications of P-FNAB are mild and we can describe this method as a safe procedure. Full article