24-hour Urinary Calcium Levels Research Articles

Continuous Subcutaneous Delivery of rhPTH(1-84) and rhPTH(1-34) by Pump in Adults With Hypoparathyroidism.

Continuous subcutaneous infusion of recombinant parathyroid hormone (rhPTH) through a pump has been proposed as a therapeutic alternative for patients with chronic hypoparathyroidism who remain symptomatic or hypercalciuric on conventional treatment (calcium and active vitamin D) or daily injections of rhPTH(1-84) or rhPTH(1-34). However, the real-world evidence of the outcome of this novel therapy is limited. We report the clinical and biochemical outcomes of 12 adults with hypoparathyroidism (11 women, age 30-70 years, and 1 man, age 30 years) from 3 different clinical sites in the United States who were transitioned from conventional therapy to daily injections of rhPTH(1-84) or rhPTH(1-34) and then switched to continuous administration of rhPTH(1-84)/rhPTH(1-34) via pump therapy. In most patients, mean serum calcium concentrations increased while on PTH pump therapy compared with both conventional therapy (in 11 patients) and single/multiple daily rhPTH injections (in 8 patients). Despite this, 10 patients had lower median 24-hour urinary calcium levels while on PTH pump therapy compared with prior therapy (mean ± SD difference: -130 ± 222 mg/24 hours). All patients reported a qualitative decrease in hypocalcemic symptoms while receiving pump therapy. Three patients had pod failure at least once, and 1 patient developed an infusion site reaction. In this case series of 12 patients with chronic hypoparathyroidism treated with rhPTH(1-84)/rhPTH(1-34) administered via a pump, improvement in clinical and biochemical parameters were observed in the majority of the patients. Our observations indicate benefits of pump administration of rhPTH that warrant further investigation.

Correlation of Body Mass Index and Age with Osteoporosis Probability in Patients with Primary Hyperparathyroidism

ObjectiveCurrently, there are limited markers to predict the osteoporosis probability in patients with primary hyperparathyroidism. We studied the relationship between various parameters and results of DXAs at various skeletal sites. MethodsRetrospective review of data for 218 patients with primary hyperparathyroidism was performed. Age, BMI, bone mineral density, serum total calcium, ionized calcium, intact parathyroid hormone, albumin, alkaline phosphatase, phosphate, 25-hydroxy vitamin D, 1,25-dihydroxy vitamin D, 24-hour urinary calcium levels and parathyroid tumor weight were analyzed. Two different statistical models- linear regression and multivariate logistic regression were performed. ResultsAt the lumbar spine, with the linear model, BMI (P < .001), alkaline phosphatase (P < .001), and ionized calcium (P < .001) significantly correlated with T scores; whereas with the logistic model, BMI was the only variable predicting osteoporosis probability.At the femoral neck, BMI (P < .022), 25-hydroxy vitamin D (P < .001), 1,25-dihydroxy vitamin D (P < .034) correlated with T scores; whereas both BMI (P < .029) and age (P < .051) were the significant variables that predicted osteoporosis.At the total hip, BMI (P < .001) and age (P < .001) correlated with T scores; whereas with the logistic model, only BMI (P < .016) predicted osteoporosis. At the forearm, a model could not be generated due to limited number. ConclusionIn patients with primary hyperparathyroidism, BMI strongly correlated with T scores and probability of osteoporosis.

Influence of deficiency or insufficiency of vitamin D on the circadian rhythm of serum calcium level

Background: mild hypocalcemia is a common laboratory finding that is not accompanied by the clinical symptoms. The most common causes of hypocalcemia are inadequate calcium intake and vitamin D deficiency. Given the high prevalence of vitamin D deficiency (insufficiency), it seems relevant to determine the daily variability of serum calcium levels before and after its supplementation.Aims: to assess the effect of 25(OH) vitamin D level on the daily profile of serum calcium and 24-hour urinary calcium levels. MATERIALS AND METHODS: the interventional, prospective, comparative study of 10 healthy volunteers (women/men - 9/1) was performed. We have analyzed the daily profiles of serum calcium and 24-hour urinary calcium levels. Summary duration of this study was 8 months and consisted two hospitalizations. Statistical analysis was done on August 2020. The descriptive statistics are represented by medians and the first and third quartiles in Me (Q1; Q3), average, maximum, and minimum values M (min; max) and by absolute and relative frequencies.Results: Me serum calcium levels (Catotaland Cacorr.) and 24-hour urinary calcium levels did not differ before and after vitamin D supplementation. However, the number of reference calcium values increased as 25 (OH) vitamin D level was reached more than 30 ng/ml from 90.8% to 100% for Catotal and from 94.2% to 97.5% for Cacorr. Episodes of hypocalcemia were registered in patients with low vitamin D levels: in 3.33% of cases according to Catotal and 5.8% for Cacorr. The frequency of hypocalcemia decreased for Catotal (to 0%) and for Cacorr. (to 2.5%) after treatment with cholecalciferol. Analysis of Catotal and Cacorr. deviations during the day showed a less variability of the calcium profile after treatment, This study also revealed circadian character of daily serum calcium profile with the presence of maximum (09:40-17:40) and minimum (23:40-07:40) values during the day.Conclusions: Our study demonstrated the improvement of daily serum calcium profile after vitamin D supplementation. We confirmed the increased number of reference calcium values, decreased variability of serum calcium levels during the day and decreased frequency of hypocalcemia.

SAT-347 Diagnosis of Autosomal Dominant Hypocalcemia Type 1 Following the Initiation of Imatinib for Treatment of Chronic Myeloid Leukemia

Background: Autosomal Dominant Hypocalcemia Type 1 is an underdiagnosed condition due to the vast majority of patients being asymptomatic and having mild hypocalcemia. Imatinib has been associated with hypophosphatemia and hypocalcemia. Clinical Case: 69-year-old man who had a long history of asymptomatic mild hypocalcemia, calcium level of 7.9 mg/dL (8.4 – 10.2 mg/dL) diagnosed with chronic myeloid leukemia and developed symptoms of hypocalcemia within 2 months of treatment with imatinib. After the initiation of imatinib, his calcium reduced to 6.8 mg/dL (8.4 – 10.2 mg/dL) with a corresponding ionized calcium of 0.98 mmol/L (1.12–1.32 mmol/L) within 2 months. He developed tetany. With the reduced calcium level his PTH was unexpectedly low-normal at 34 pg/mL (16–62 pg/mL). He also had a higher than expected urinary calcium of 342 mg/24 hours. The PTH and 24-hour urinary calcium levels raised concern for an underlying diagnosis of autosomal dominant hypocalcemia type 1. His phosphorous was normal at 3.3 mg/dL (2.6–4.9 mg/dL). He never had hypophosphatemia, which is common with imatinib.After two doses of IV calcium and initiation of oral calcium replacement, 1000 mg BID, his level continued to be reduced with symptoms. Given his symptoms, laboratory results, and continued hypocalcemia he underwent genetic testing. Results of his genetic testing showed a p.Thr151Met mutation in the CASR gene consistent with autosomal dominant hypocalcemia type 1. With this diagnosis, there is concern for nephrolithiasis with over treatment. His symptoms resolved with treatment with calcium 1000mg TID, calcitriol 0.25 mg BID and vitamin D3 2000 IU daily. He has not developed nephrolithiasis and his urinary calcium increased to 424mg/24 hours. A thiazide diuretic is being considered to decrease urinary calcium excretion.He continues on imatinib with an excellent response to therapy. It is likely that the trigger for symptomatic severe hypocalcemia was initiation of imatinib superimposed on the hypocalcemia type 1. Possible mechanisms for this are decreased intestinal absorption, increased urinary loss, or decreased dissolution from bone. 1 These mechanisms are also associated with hypophosphatemia, which our patient did not have. Another possible cause could be an immune mediated destruction of the parathyroid gland, a rare finding seen with other tyrosine kinase inhibitors.2 Conclusion: This is the first reported case of imatinib triggering severe symptomatic hypocalcemia leading to the diagnosis of underlying autosomal dominant hypocalcemia type 1.

Bone mineral density and its correlation with serum 25-hydroxyvitamin D levels in patients with hyperthyroidism.

ObjectiveThis study aimed to determine the association between 25-hydroxyvitamin D (25(OH)D) levels and bone mineral density (BMD) in patients with hyperthyroidism after undergoing treatment.MethodsA total of 120 patients with hyperthyroidism were selected as participants. Methimazole tablets were provided to all of the participants, with an initial dose of 20 mg/day and a maintenance dose of 2.5 mg/day for 1 year. Blood calcium, phosphate, parathyroid hormone (PTH), and thyroid hormone levels were assayed using an automatic biochemical analyzer. Levels of 25(OH)D and bone alkaline phosphatase (ALP) in serum were determined by enzyme-linked immunosorbent assay. BMD was measured using dual energy X-ray absorptiometry.ResultsSerum phosphorus, PTH, and 25(OH)D levels in patients with hyperthyroidism were significantly higher, and bone ALP and 24-hour urinary calcium levels were significantly lower after treatment compared with before treatment. BMD in patients with hyperthyroidism was significantly improved after treatment. In logistic regression analysis of BMD-related risk factors, bone ALP, PTH, and 25(OH)D levels were risk factors of BMD.ConclusionTreatment for hyperthyroidism should be supplemented with vitamin D and calcium, which have important clinical significance for adjusting bone metabolism and delaying the process of osteoporosis.

Gender differences in bone mineral density in patients with sporadic primary hyperparathyroidism.

SummaryContextPrimary hyperparathyroidism reduces bone mineral density, which increases the risk of fracture.ObjectiveTo investigate differences in bone mineral density and clinical characteristics after parathyroidectomy between men and women (premenopausal and postmenopausal) with sporadic primary hyperparathyroidism.DesignThis is a retrospective study of adult patients who underwent parathyroidectomy in a tertiary referral center from 1990 to 2013.PatientsA total of 1529 patients underwent parathyroidectomy during the study period; 80 patients met the inclusion criteria. Of these, 24 were men and 56 were women (10 premenopausal and 46 postmenopausal).MeasurementsDemographics, preoperative and postoperative biochemical analysis, preoperative and postoperative T‐scores, preoperative Z‐scores, preoperative and postoperative absolute bone mineral density values, and percentage change in bone mineral density from baseline to 12 ± 6 months after parathyroidectomy in the lumbar spine, femoral neck, total hip and distal one‐third of the nondominant radius.ResultsPreoperative 24‐hour urinary calcium levels were significantly higher in men than in women overall (P = 0.02) and postmenopausal women (P = 0.01). Men had significantly lower preoperative Z‐scores than women overall, premenopausal women and postmenopausal women. Men had greater percentage change of increase in bone mineral density in the femoral neck than did women overall (2.77%; P = 0.04) and postmenopausal women (2.98%; P = 0.03) 1 year after parathyroidectomy.ConclusionsFrom this study, men demonstrated a greater improvement of bone mineral density in the femoral neck from baseline after parathyroidectomy compared with women.

Clinical Features and Prognostic Significance of Liver Involvement in Sarcoidosis

Background:Sarcoidosis is a systemic disease, characterised by non-caseating granulomas in various organs. Liver involvement is not an uncommon feature of sarcoidosis. However, firm data establishing the clinical features and prognosis in these patients are lacking, although the incidence of liver sarcoidosis is high. In this study, we aimed to investigate the features of liver involvement in patients with sarcoidosis. Another aim was to evaluate the prognostic significance of liver disease by comparing the differences between patients with no liver involvement, limited and diffuse liver involvement.Methods:We conducted a retrospective study to evaluate the clinical and laboratory findings of 271 sarcoidosis patients seen at our institution. Patients with liver sarcoidosis identified by liver biopsy were compared to patients without liver involvement for clinical features and prognosis. The biopsy sample was considered positive if it demonstrated non-caseaiting granulomas with negative fungal and mycobacterial cultures. The patients were classified into three groups according to the radiological and histopathological biopsyresults:no liver involvement; limited liverinvolvement:two sites positive; and diffuse liverinvolvement:three or more sites positive for granulomas.Results:Hepatic involvement was identified by biopsy in 81 (81/271, 29.8%) while 43 (43/271, 15.8%) patients had elevated liver function tests. Most of the patients (94.6%) had lung involvement. Other organs involved, in the order of frequency,were:lymph nodes, skin, eye, spleen and parotid gland. There was no significant difference between the three groups for forced expiratory volume in one second, forced vital capacity, total lung capacity, diffusing capacity of the lungs for carbon monoxide/alveolar volume, serum and 24-hour urinary calcium levels. Serum angiotensin-converting enzyme levels were significantly higher (p&lt;0.01) in patients with diffuse liver involvement than patients with no or limited liver disease. Progressive disease was more frequent (p&lt;0.01) in patients with diffuse liver disease. Extra-pulmonary organ involvement was significantly different between the three groups (p&lt;0.01).Conclusions:Diffuse liver involvement in sarcoidosis is a significant risk factor for progressive disease. Patients with diffuse liver disease have a worse prognosis than patients without or with limited liver involvement. Diffuse hepatic involvement in sarcoidosis is also associated with an increased incidence of extra-pulmonary organ involvement. Presence of diffuse liver disease may reveal a severe prognosis for sarcoidosis patients.

MORBIDITY AND RESULTS OF RETROGRADE FLEXIBLE URETEROSCOPY AND LASER LITHOTRIPSY IN 864 PATIENTS

We have previously reported a high rate of urinary metabolic abnormalities in stone forming children compared to normal controls. At our institution a 24-hour urine evaluation is initiated after the first stone episode in children, to measure stone risk indices. The purpose of this study was to determine which children are at the greatest risk for recurrent stone formation.A retrospective cohort study was performed to assess urinary metabolic profiles in children with urolithiasis. In all patients 24-hour urine collections were performed and evaluated elsewhere. Urine chemistry assessments such as calcium and citrate were adjusted for creatinine and weight. Calcium oxalate supersaturation was measured. Patients were stratified as solitary or recurrent stone formers based on review of the medical record. Univariate analysis between means was performed with a 2-tailed t test.A total of 148 samples from 88 solitary stone formers and 84 samples from 51 recurrent stone formers were evaluated. Age and gender were well matched between the 2 groups. Timed urinary calcium levels referenced to creatinine and citrate were significantly higher in patients with recurrent stones. Supersaturation levels of calcium oxalate were higher in recurrent stone formers but did not reach statistical significance.There are significant differences in 24-hour urinary calcium levels between solitary and recurrent calcium stone forming children. A patient with increased urinary calcium indices on a 24-hour specimen may benefit from more aggressive initial dietary and pharmacological treatment to prevent stone recurrence.

Urinary Metabolic Evaluations in Solitary and Recurrent Stone Forming Children

We have previously reported a high rate of urinary metabolic abnormalities in stone forming children compared to normal controls. At our institution a 24-hour urine evaluation is initiated after the first stone episode in children, to measure stone risk indices. The purpose of this study was to determine which children are at the greatest risk for recurrent stone formation. A retrospective cohort study was performed to assess urinary metabolic profiles in children with urolithiasis. In all patients 24-hour urine collections were performed and evaluated elsewhere. Urine chemistry assessments such as calcium and citrate were adjusted for creatinine and weight. Calcium oxalate supersaturation was measured. Patients were stratified as solitary or recurrent stone formers based on review of the medical record. Univariate analysis between means was performed with a 2-tailed t test. A total of 148 samples from 88 solitary stone formers and 84 samples from 51 recurrent stone formers were evaluated. Age and gender were well matched between the 2 groups. Timed urinary calcium levels referenced to creatinine and citrate were significantly higher in patients with recurrent stones. Supersaturation levels of calcium oxalate were higher in recurrent stone formers but did not reach statistical significance. There are significant differences in 24-hour urinary calcium levels between solitary and recurrent calcium stone forming children. A patient with increased urinary calcium indices on a 24-hour specimen may benefit from more aggressive initial dietary and pharmacological treatment to prevent stone recurrence.

Assessment of Bone and Mineral Metabolism in Inflammatory Bowel Disease: Case Series and Review

To determine the prevalence of low bone mass, fractures, and vitamin D deficiency and the levels of biochemical markers of mineral metabolism in patients with inflammatory bowel disease (IBD). Our retrospective study consisted of 30 patients with Crohn's disease (CD) and 18 patients with ulcerative colitis (UC). Dual-energy x-ray absorptiometry was performed to determine bone mineral density at the lumbar spine and hip. Serum calcium, phosphorus, parathyroid hormone, 25-hydroxyvitamin D (25-OHD), and 1,25-dihydroxyvitamin D, urinary N-telopeptide cross-linked collagen type I, and 24-hour urinary calcium levels were evaluated. On the basis of Z-score definitions of low bone mass in the IBD group as a whole, 13 patients (27%) had low bone mass at the lumbar spine. Similarly, at the femoral neck, 13 patients (27%) had low bone mass. There was a higher prevalence of low bone mass in the UC group than in the CD group, consistent with a high prevalence of fractures in that group. Of all patients with IBD, 65% had a history of fractures, of which 23% were atraumatic. Deficiency of 25-OHD was high, with a prevalence of 55% in patients with UC and 83% in patients with CD. Secondary hyperparathyroidism, defined as a parathyroid hormone level >55 pg/mL in conjunction with a low or normal serum calcium and a low 25-OHD level, was present in 50% of patients with CD and only 7% of patients with UC. Metabolic bone disease and fractures are common in IBD. The mean bone mineral density of the spine or femoral neck did not differ significantly between patients with CD and those with UC. Patients with UC had a higher prevalence of low bone mass, as defined by a Z-score of less than -2, than did patients with CD, consistent with a high prevalence of fractures in the UC group. In contrast, hyperparathyroidism attributable to vitamin D deficiency was more prevalent in patients with CD than in those with UC. This finding suggests a different etiologic mechanism of low bone mass in patients with CD.

Renal function following combination chemotherapy with ifosfamide and cisplatin in patients with osteogenic sarcoma.

Ifosfamide and cisplatin are active agents that are currently used in the treatment of osteosarcoma. Nephrotoxicity has been reported following their use in combination and alone. This study evaluates renal function in children and adolescents (median age 16 years) at least 3 months following completion of a chemotherapy regimen which included 54 g/m2 ifosfamide, 360 mg/m2 cisplatin, doxorubicin, and high-dose methotrexate. Mean glomerular filtration rate (GFR) was determined by inulin or iothalamate clearance; proximal tubular function was evaluated by measuring fractional excretion of glucose (FEglu), tubular maximum phosphate reabsorption per GFR (TMP/GFR), FE of urate, and 24-hour amino acid excretion. Distal tubular function was evaluated by 24-hour urinary calcium, FE of magnesium, and urinary osmolality after water deprivation. Twenty-four-hour urinary protein excretion was measured. The mean GFR was 97 ml/min/1.73 m2. Although 10 of 24 patients had GFRs lower than normal, the lowest value was only 22% below the lower limit of normal and would not account for any clinical compromise. Proximal tubular function evaluation revealed normal FEglu, normal mean TMP/GFR values, and high FE of urate (1 5.7%). Two of twenty-four patients were shown to have mild generalized aminoaciduria. Distal tubular function evaluation showed normal 24-hour urinary calcium levels (mean 3.4 mg/kg) and FE of magnesium as well as normal urinary osmolality. Twenty-four-hour urinary protein excretion was normal in all patients. The lack of clinically significant renal abnormalities observed in patients who received combination chemotherapy with ifosfamide and cisplatin for osteosarcoma is encouraging for future osteosarcoma protocol development.