Serum Intact Parathyroid Hormone Concentrations Research Articles

5-year Follow-up of Reimplanted Parathyroid Glands in Forearm Subcutaneous Tissue During Thyroidectomy. A Confirmation of Graft Vitality in a Large Series of Patients.

The aim of this study is to assess the outcomes of parathyroid gland reimplantation with PR-FaST technique in patients undergoing thyroid surgery, focusing on graft functionality over a 5-year follow-up period. We analyzed data from 131 patients who underwent parathyroid reimplantation using the PR-FaST technique during thyroid surgery due to inadvertent parathyroid removal or evident vascular damage. Postoperative evaluations included serum calcium (Ca), magnesium (Mg), and phosphorus (P) analyses on the 1st and 2nd postoperative days, at 10 days, and at 1, 3, 6months, 1 year, and 5 years of follow-up. Additionally, the mean values of serum intact parathyroid hormone (iPTH) concentration were measured from blood samples collected from both the reimplanted arm (iPTH RA) and non-reimplanted arm (iPTH NRA) within the same period. Among 131 patients, at 10 days post-surgery, only 46 patients (35.1%) out of 131 exhibited graft viability (iPTH ratio >1.5). This percentage increased to 72.8% (94 patients) after 1 month and further to 87.8% (108 patients) after 3 months post-surgery. At 1 year, 84.7% of patients showed good graft functionality. After 5 years, the percentage remained stable, with graft viability observed in 81.3% of patients. Only 91 of the initial 131 patients completed follow-up up to 5 years, with a dropout rate of 30.5 %. Parathyroid reimplantation using the PR-FaST technique is a viable option for patients undergoing thyroidectomy and has been shown to be a reproducible and effective technique in most patients, with sustained graft functionality and parathyroid hormone production over a 5-year follow-up period.

A reappraisal of risk factors for early hypocalcemia after parathyroidectomy in dialysis patients.

We aimed to identify risk factors for early hypocalcemia after parathyroidectomy in patients with secondary hyperparathyroidism. We retrospectively enrolled 106 of 120 consecutive patients with secondary hyperparathyroidism who underwent parathyroidectomy between January 2019 and July 2021. Perioperative laboratory parameters, preoperative computerized tomography (CT) images, and postoperative histology were evaluated. Parathyroid calcification was defined as hyperdense regions with a density of > 130 Hounsfield Units on CT images of the parathyroid. Subtotal parathyroidectomy, total parathyroidectomy without auto-transplantation, or total parathyroidectomy with auto-transplantation were performed in the present study. Postoperative hypocalcemia was defined as a serum calcium concentration < 2.1mmol/L within 4days of surgery. The participants were categorized according to the presence (n = 33) or absence (n = 73) of postoperative hypocalcemia. The demographics, comorbidities, and surgical details were similar in the two groups. Multivariate analysis showed that the preoperative alkaline phosphatase activity, serum intact parathyroid hormone and calcium concentrations, and parathyroid calcification were independent risk factors for postoperative hypocalcemia (all P < 0.05). Receiver operating characteristic analysis generated areas under the curves for preoperative alkaline phosphatase, intact parathyroid hormone, and parathyroid calcification of 0.82, 0.80, and 0.70, respectively (all P < 0.05). Cut-off values for preoperative alkaline phosphatase (> 242.9IU/L) and intact parathyroid hormone (> 2,104pg/mL) were found to be predictive of postoperative hypocalcemia. High preoperative alkaline phosphatase activity and serum intact parathyroid hormone concentration and low serum calcium are associated with higher risks of postoperative hypocalcemia. Calcification of the parathyroid may represent a novel radiologic means of predicting postoperative hypocalcemia.

Surgical management of secondary hyperparathyroidism in dialysis patients in Senegal.

Secondary hyperparathyroidism (SHPT) is a common complication of end-stage renal disease. Surgical management occurs in severe forms and/or unresponsive medical treatment. The aim of this study was to outline the indications of parathyroidectomy and its evolution after surgical approach. It was a five-year multicenter backward study in Otorhinolaryngology Department of Fann Hospital and four dialysis centers in Dakar. We include all patients with SHPT who underwent surgery. Preoperative clinical and paraclinical parameters, clinical-biological evolution, and histology findings of the resected parathyroid specimen were collected. Out of 58 patients with hyperparathyroidism, 18 patients required parathyroidectomy, corresponding to a prevalence of 31%. Mean age of patients was 46.6 ± 15.29 years and sex ratio 0.61. Mean duration on dialysis was 44.4 ± 30 months. Ten patients (55.56%) had bone pain and nine patients (50%) had joint pain. Mean serum calcium was 97.27 ± 8.66 mg/L. Mean blood phosphorus levels were 40.47 ± 9.99 mg/L. Mean iPTH rate was 1493.22 ± 1014.93 ng/mL, with a maximum of 5000 ng/mL (77N). Mean value of 25-OH Vitamin D was 32.89 ± 16.02 ng/mL. Parathyroidectomy was indicated after failure of medical treatment with persistence of a serum intact parathyroid hormone concentration above 800 μg/mL in all patients. Subtotal parathyroidectomy (7/8) was performed in 11 patients (61.1%). Two patients (11.11%) benefited from a selective parathyroidectomy (3/4). Evolution was favorable for 13 patients, corresponding to a success rate of 72.2%. It was unfavorable in five patients including one patient with hypoparathyroidism and four patients with recurrent hyperparathyroidism. Surgery for patients with renal hyperparathyroidism in the era of calcimimetics continues to play an important role in selected patients and achieves efficient control of hyperparathyroidism in developing countries.

Predictors of early postoperative hypocalcemia in patients with secondary hyperparathyroidism undergoing total parathyroidectomy.

ObjectiveTo summarize the clinical features of secondary hyperparathyroidism (SHPT) in patients with chronic renal failure and to explore the predictive factors of postoperative hypocalcemia after total parathyroidectomy in these patients.MethodsThe clinical data of 87 patients admitted to Guangdong Electric Power Hospital from May 2013 to February 2020 were reviewed. All patients underwent total parathyroid resection and sternocleidomastoid microtransplantation. Age, sex, and the serum calcium, phosphorus, alkaline phosphatase (ALP), and intact parathyroid hormone (iPTH) concentrations were analyzed as predictive factors of postoperative hypocalcemia.ResultsBone pain was the most common clinical manifestation in this study population, and all 87 patients experienced relief from their clinical symptoms after the surgical procedure. Age and the preoperative serum calcium, ALP, and iPTH concentrations were determined to be early predictive factors of postoperative hypocalcemia.ConclusionsAge and the preoperative calcium, ALP, and iPTH concentrations are independent risk factors for postoperative hypocalcemia in patients with SHPT and renal disease who undergo total parathyroidectomy with sternocleidomastoid microtransplantation. These factors can help identify high-risk patients who can be managed by a multidisciplinary team to improve graft survival and quality of life.

Reduction in parathyroid adenomas by cinacalcet therapy in patients with primary hyperparathyroidism.

Cinacalcet is a calcimimetic that modulates the functions of calcium-sensing receptor and is currently used to treat patients with primary hyperparathyroidism (PHPT). Although it was reported that cinacalcet treatment reduced the size of hyperplastic parathyroid glands in patients with secondary hyperparathyroidism, whether or not cinacalcet treatment can reduce the size of parathyroid adenomas in patients with PHPT has been unknown. We recruited nine (male: one, female: eight) patients with PHPT due to parathyroid adenomas who did not undergo parathyroidectomy. Cinacalcet was administered at a dose of 50mg/day, and we evaluated the size of parathyroid adenomas (width × thickness) (mm2) using ultrasonography before and after 6months of cinacalcet treatment. The mean age of the subjects was 58.1 ± 7.2years old, and the mean serum intact parathyroid hormone (PTH) concentration was 134.8 ± 8.7pg/ml. All participants showed hypercalcemia and osteopenia. After 6months, the mean size of parathyroid adenomas was significantly decreased (baseline: 73.8 ± 33.4mm2 vs. after 6months: 52.5 ± 25.0mm2, p = 0.045). Thus, 6-month cinacalcet treatment induced a 29% size reduction in parathyroid adenomas. Furthermore, the serum intact PTH concentration before cinacalcet treatment was positively correlated with the reduction in the size of parathyroid adenomas. The present study revealed that cinacalcet treatment reduces the size of parathyroid adenomas in patients with PHPT. The accumulation of more PHPT cases with cinacalcet therapy is required to confirm this finding.

Effect of High Volume Hemodiafiltration on Secondary Hyperparathyroidism Among Hemodialysis Patients

<i>Background: </i>Despite increasing knowledge of the uraemic syndrome, both morbidity and mortality remain unacceptably high in patients with chronic kidney disease. <i>Aim of the work: </i>investigate the differences between conventional hemodialysis and hemodiafiltration in the context of chronic kidney disease metabolic bone disease findings serum calcium (sCa), phosphate (sPO4) and intact parathyroid hormone (PTHint) concentrations. <i>Patients and methods: </i>This prospective cross over study was approved by Almaadi hospital committee and included 95 patients with CKD5 on regular hemodialysis for at least 6 months. Patients were divided into two groups: Group A: 60 patients scheduled 6 months conventional high flux (hf-HD) (Period1) followed by 6 months of post-dilutional–HDF (Period2). Group B: (controls) included 35 patients were kept on conventional hf-HD for 12 months. (Period3) for 1^st 6 months and (Period4) for 2^nd 6 months. The main variables evaluated at the start as well as at the end of each period were sCa, sPO4 and PTHint. <i>Results: </i>There was highly significant statistical decrease in Phosphorus level in period2 compared to other groups after 2^nd to 6^th month and average of overall (p<0.001). A significant statistical decrease was found in Parathormone level and CRP in period2 compared to other groups after 1 month to 6^th month and average of overall (p<0.05). There was significant statistical decrease in Albumin level in period2 compared to other groups after 2^nd to 6^th month and average of overall (p<0.05). There was a significant statistical increase in kt/v in period2 compared to other groups after 1^st to 6^th month and average of overall (p<0.05). <i>Conclusion: </i>The switch over from conventional Hf-HD to Ol-HDF results in a significant reduction of both PO4 and PTH concentrations, no significant changes in Ca concentrations.

Exacerbation of Hyperparathyroidism, Secondary to a Reduction in Kidney Function, in Individuals With Vitamin D Deficiency.

Aims/Introduction: Chronic kidney disease (CKD)-mineral and bone disorders (CKD-MBD) are an adverse outcome derived from decreases in kidney function, where abnormality of serum concentrations of calcium (Ca), phosphorus, parathyroid hormone (PTH), and vitamin D can be seen simultaneously. To identify individuals at risk for CKD-MBD or secondary hyperparathyroidism, the relationships between estimated glomerular filtration rate (eGFR) and serum PTH concentration were evaluated, allowing for confounding factors, in particular vitamin D status, in a general Japanese population.Materials and Methods: Nine-hundred-and-thirty participants in the population-based Iwaki study conducted in 2016 who were not on drugs affecting mineral metabolism nor hemodialysis, were included in the study (326 men and 604 women; age: 55.4 ± 15.9 years).Results: Regression analysis showed a significant correlation between eGFR and serum intact PTH concentration, after adjustment for possible confounding factors (β = −0.122, p < 0.001). The smoothed spline curve applied for the correlation analysis revealed a biphasic correlation, with a division at an eGFR of ~60 mL/min/1.73 m2, below which the correlation coefficient was higher (β = −0.405, p < 0.001). Stratification on the basis of vitamin D status showed that the correlation was present only in participants with vitamin D deficiency (25-dihydroxyvitamin D3: <15 pg/mL) (β = −0.154, p < 0.001).Conclusions: These results indicate that a reduction in eGFR is a significant risk factor for an increase in serum PTH concentration when it is <60 mL/min/1.73 m2 and vitamin D is deficient, in the general Japanese population.

Conversion from Intravenous Vitamin D Analogs to Oral Calcitriol in Patients Receiving Maintenance Hemodialysis.

In the United States, intravenous vitamin D analogs are the first-line therapy for management of secondary hyperparathyroidism in hemodialysis patients. Outside the United States, oral calcitriol (1,25-dihydroxyvitamin D3) is routinely used. We examined standard laboratory parameters of patients on in-center hemodialysis receiving intravenous vitamin D who switched to oral calcitriol. We conducted a retrospective cohort study of adult patients treated within Fresenius Kidney Care clinics. During a 6-month period (December 2013 to May 2014), we identified patients on an intravenous vitamin D analog (doxercalciferol or paricalcitol) who switched to oral calcitriol and matched them to patients receiving an intravenous vitamin D analog. Mean serum calcium, phosphate, and intact parathyroid hormone (iPTH) concentrations were examined for up to 12 months of follow-up. We used Poisson and Cox proportional hazards regression models to examine hospitalization and survival rates. The primary analysis was conducted as intention-to-treat; secondary analyses included an as-treated evaluation. A total of 2280 patients who switched to oral calcitriol were matched to 2280 patients receiving intravenous vitamin D. Compared with patients on intravenous vitamin D, mean calcium and phosphate levels in the oral calcitriol group were lower after the change to oral calcitriol. In contrast, iPTH levels were higher in the oral calcitriol group. At 12 months, the percentage of patients with composite laboratories in target range (calcium <10 mg/dl, phosphate 3.0-5.5 mg/dl, and iPTH 150-600 pg/ml) were comparable between groups (45% versus 45%; P=0.96). Hospital admissions, length of hospital stay, and survival were comparable between groups. An as-treated analysis and excluding those receiving cinacalcet did not reveal significant between-group differences. Among patients receiving in-center hemodialysis who were switched to oral calcitriol versus those on an intravenous vitamin D analog, the aggregate of all mineral and bone laboratory parameters in range was largely similar between groups.

Hemodialysis patients with low serum parathyroid hormone levels have a poorer prognosis than those with secondary hyperparathyroidism.

Background:Low serum parathyroid hormone (PTH) level and secondary hyperparathyroidism (SHPT) are very common in hemodialysis patients. However, the outcomes of patients with low PTH level or SHPT have not been carefully compared. Therefore, in the present study, we compared the outcomes of hemodialysis patients with low PTH level or SHPT.Methods:This was a multi-center, prospective, cohort study of 647 patients. The patients were recruited between 1 September 2016 and 1 January 2017 and followed until 31 December 2018. The participants were allocated to a low PTH group [serum intact PTH (iPTH) concentration < 60 pg/ml] and an SHPT group (iPTH ⩾ 600 pg/ml) according to their mean iPTH concentration across the entire observation period, and the outcomes were compared between these groups. The primary outcome was a composite outcome, which comprised all-cause mortality, non-fatal acute myocardial infarction, non-fatal acute stroke, and acute heart failure.Results:A total of 197 hemodialysis patients were allocated to the two groups: 87 with low PTH level and 110 with SHPT; 450 patients with time-averaged iPTH concentrations of 60–600 pg/ml were excluded. Kaplan–Meier analysis of the composite endpoint revealed a significant difference between participants with low PTH level and those with SHPT (p = 0.002). Cox multiple regression showed that participants with low PTH level had a higher incidence of the composite endpoint than those with SHPT (relative risk: 1.337, 95% confidence interval: 1.059–1.688).Conclusion:Hemodialysis patients with low PTH level had a higher incidence of mortality and non-fatal cardiovascular events than those with SHPT, irrespective of whether the participants were age-matched.

Incidence of and risk factors for post-parathyroidectomy hungry bone syndrome in patients with secondary hyperparathyroidism

Background Hungry bone syndrome (HBS) following parathyroidectomy is associated with severe hypocalcemia and increased morbidity. This study aims to determine the incidence and risk factors of post-parathyroidectomy HBS in dialysis patients with secondary hyperparathyroidism (SHPT). Methods A retrospective cohort study was conducted, and medical records of patients with SHPT requiring parathyroidectomy between January 2014 and January 2020 were reviewed. HBS was defined as the requirement of intravenous calcium administration due to hypocalcemia-related symptoms and/or reductions in serum calcium concentration (<8.4 mg/dL) within 72 h after parathyroidectomy. Results A total of 130 dialysis patients were enrolled. The majority of patients (85.4%) received hemodialysis and the remaining patients (14.6%) received peritoneal dialysis. Ectopic parathyroid glands were identified in 6.6% of patients by preoperative parathyroid scintigraphy. Diffuse parathyroid hyperplasia was the most common histopathological characteristic of SHPT (90.8%). HBS occurred in 82.3% of patients following parathyroidectomy. Preoperative serum intact parathyroid hormone (iPTH) concentration was significantly correlated with serum calcium (r = −0.48, p < 0.01) and alkaline phosphatase (ALP) concentration (r = 0.71, p < 0.01). Patients with HBS had significantly longer hospital stays than patients without (8 versus 3 days, p < 0.01). Based on multiple logistic regression analysis, young age (≤45 years), high preoperative serum ALP (>420 IU/L) and iPTH (>1,000 pg/mL), and absence of preoperative hypercalcemia (>10.2 mg/dL) were significantly associated with HBS. Conclusions Post-parathyroidectomy HBS is common in dialysis patients with SHPT. Young age, high preoperative serum ALP and iPTH, and low preoperative serum calcium concentrations were important risk factors for HBS.

Paradoxical Response of Parathyroid Hormone to Vitamin D–Calcium Supplementation in Indian Children

To investigate the effect of oral vitamin D-calcium supplementation on serum intact parathyroid hormone (PTH), calcium, phosphorous, and alkaline phosphatase (ALK-P) concentrations in children with habitually low calcium intakes. In this follow-up study to a randomized controlled trial that aimed to assess the effect of vitamin D-calcium supplementation on immunity, data related to dietary intake, anthropometry, and biochemistry [serum 25(OH)D and bone profile] were collected from 178 children-79 in the vitamin D group and 99 in the non-vitamin D group. Dietary calcium to phosphorus intake ratio was 0.4:1. Baseline serum 25(OH)D concentration was 58.2±10.9nmol/L; 66% children were vitamin D sufficient and none deficient. After supplementation, vitamin Dgroup, compared with the non-vitamin D group, had significantly (P<.05) greater 25(OH)D (83.9±30.1nmol/L vs 58.3±15.7nmol/L), significantly greater PTH (6.7±3.6 pmol/L vs 5.5±3.2 pmol/L), and positive correlation (rs=0.24) between serum 25(OH)D and PTH (vs negative correlation [rs=-0.1] in non-vitamin D group). Mean concentrations of serum bone measures in the vitamin D group were calcium (2.2±0.1mmol/L), phosphorus (1.7±0.2mmol/L), and ALK-P (178.7±40.7 IU/L). At follow-up, 1-year post-supplementation, in the vitamin D group, PTH concentrations continued to remain high (but not significantly different from levels at 6months), with low normal serum calcium, high normal phosphate, and ALK-P in reference range. In children who are vitamin D sufficient but with habitually low dietary calcium intake, vitamin D-calcium supplementation paradoxically and significantly increased serum PTH concentrations with no apparent effect on other bone biochemistry. Chronic low dietary calcium to phosphorus ratio is likely to have caused this paradoxical response.

Poor vitamin D status increases the risk of anemia in school children: National Food and Nutrition Surveillance.

This study aimed to investigate the association between 25-hydroxyvitamin D (25[OH]D) concentrations and the risk of anemia in a large cohort of children with consideration for the effects of sex, body mass index (BMI), serum intact parathyroid hormone (iPTH) concentrations, and iron level status. A total of 937 children (493 boys, 444 girls) ages 9 to 12y were enrolled in a cross-sectional study. The children underwent various examinations including anthropometric measurements and blood sampling. Overall, 13.3% of the children were anemic and 64.2% and 28.1% of the subjects had a vitamin D deficiency (<25nmol/L) and insufficiency (25-50nmol/L), respectively. Approximately 13% of the children had concurrent low hemoglobin and hypovitaminosis D levels. The prevalence of hypovitaminosis D in the group of children with anemia was 96.8% compared with 91.6% in the non-anemic group (P=0.046). Mean 25(OH)D concentrations were significantly lower in the anemic children compared with the non-anemic children (19.6±13.3 vs. 24.0±23.1nmol/L; P=0.003). After controlling for sex and BMI, children with a vitamin D deficiency were almost 3.45 times more likely to be anemic compared with children with a vitamin D sufficiency (95% confidence interval [CI], 1.21-9.81). The increased risk of anemia was found to start significantly at 25(OH)D<44nmol/L (17.6ng/mL; odds ratio: 2.29; 95% CI, 1.07-4.91, P=0.032). These findings strongly suggest an association between low circulating concentrations of 25(OH)D and anemia in a large, representative sample of children, even after adjustment for sex, age, BMI, and iPTH.

Long-Term Assessment of the Safety and Efficacy of PA21 (Sucroferric Oxyhydroxide) in Japanese Hemodialysis Patients With Hyperphosphatemia: An Open-Label, Multicenter, Phase III Study

The objective of this article was to assess the safety and efficacy of long-term administration of PA21. Phase III, open-label, long-term study in 15 sites in Japan. Japanese hemodialysis patients (N=161) with hyperphosphatemia aged ≥20years undergoing stable maintenance hemodialysis 3 times weekly, for ≥12weeks. After a 2-week observation period with their previous hyperphosphatemia therapy, patients began the 52-week treatment with PA21, which was administered orally at an initial dose of 250mg, 3 times daily, immediately before every meal (dosing range between 750 and 3,000mg/day). Safety was evaluated based on the development of adverse events and adverse drug reactions (ADRs). Efficacy was evaluated according to serum phosphorus concentration, corrected serum calcium concentration, and serum intact-parathyroid hormone concentration. The mean serum phosphorus concentration decreased from 5.46±1.06mg/dL at baseline to 5.00±1.17mg/dL at end of treatment. The serum phosphorus concentration was maintained within the target range (3.5-6.0mg/dL) throughout the 52weeks of the study period with a mean of 3.3 tablets per day of PA21. Most ADRs were mild, transient, and developed early during treatment, and the incidence was not shown to increase with long-term treatment. The most frequently reported ADR was diarrhea (22.4%). Treatment with PA21 was effective in lowering and maintaining target serum phosphorus concentrations in Japanese hemodialysis patients with hyperphosphatemia over 52weeks. PA21 was generally well tolerated in the long term.

Is there a role for newer biomarkers in chronic kidney disease-mineral and bone disorder management?

The current management of Chronic Kidney Disease-Mineral Bone Disorder (CKD-MBD) relies largely on clinical judgement and assessment of biochemical parameters including serum calcium, phosphate and intact parathyroid hormone concentrations. In the past two decades, there has been a leap in the understanding of the pathophysiology of CKD-MBD, leading to the discovery of novel biomarkers. The potential utility of these markers in this clinical setting is an area of intense investigation. In the absence of any guidelines aiding the clinician's understanding and application of these markers, we summarise the current available literature surrounding fibroblast growth factor-23, α-Klotho, sclerostin and serum calcification propensity testing and their respective assays in the context of CKD-MBD management.

Inadvertent parathyroidectomy during total thyroidectomy and central neck dissection for papillary thyroid carcinoma

The main drawback of central neck lymph node dissection is postoperative parathyroid failure. Little information is available concerning inadvertent resection of the parathyroid glands in this setting and its relationship to postoperative hypoparathyroidism. Our aim was to determine the prevalence of inadvertent parathyroidectomy during total thyroidectomy and central neck dissection for papillary thyroid cancer and its impact on short-and long-term parathyroid function. This was a prospective observational study of consecutive patients undergoing first-time total thyroidectomy with a central neck dissection for papillary carcinoma >10mm. Prevalence and risk factors for inadvertent parathyroidectomy were recorded. Serum calcium and intact parathyroid hormone concentrations were determined 24hours after operation and then periodically in patients developing postoperative hypocalcemia. All patients were followed for a minimum of one year. Whole gland (n=33) or microscopic parathyroid fragments (n=14) were identified in 47/170 (28%) operative specimens. The lower parathyroid glands were involved more often. Variables influencing inadvertent parathyroidectomy were extrathyroidal extension of the tumor and therapeutic lymphadenectomy. Neither lateral neck dissection nor the number of lymph nodes retrieved affected the rate of inadvertent parathyroid resection. Postoperative hypocalcemia and permanent hypoparathyroidism were more frequent after inadvertent parathyroidectomy (64% vs 46% and 15% vs 4%; P≤.03 each). Inadvertent parathyroidectomy during total thyroidectomy with central neck dissection for papillary thyroid carcinoma is common and involves the inferior glands more frequently in patients with extended resections and clinical N1a disease. Inadvertent resection of parathyroid glands is associated with greater rates of postoperative hypocalcemia and permanent hypoparathyroidism.

Pharmacodynamic Effects of Sucroferric Oxyhydroxide and Sevelamer Carbonate on Vitamin D Receptor Agonist Bioactivity in Dialysis Patients

Background: Many patients with chronic kidney disease are prescribed vitamin D receptor agonists (VDRAs) for the management of secondary hyperparathyroidism. Oral phosphate binders may interact with, and potentially reduce the therapeutic activity of, oral VDRAs. This post hoc analysis of a Phase 3 study evaluated the pharmacodynamic effects of the iron-based phosphate binder sucroferric oxyhydroxide (SFOH) and sevelamer (SEV) carbonate on VDRA activity in dialysis patients. Methods: One thousand and fifty nine patients were randomized to SFOH 1.0-3.0 g/day (n = 710) or SEV 2.4-14.4 g/day (n = 349) for up to 52 weeks. Potential interactions of SFOH and SEV with VDRAs were assessed using serum intact parathyroid hormone (iPTH) concentrations as a pharmacodynamic biomarker. Three populations of SFOH- and SEV-treated patients were analyzed: Population 1 (n = 187), patients taking concomitant stable doses of oral VDRAs only; Population 2 (n = 250), patients taking no concomitant VDRAs; Population 3 (n = 68), patients taking concomitant stable doses of intravenous paricalcitol only. Populations were compared using a mixed-effects model to obtain the least squares mean change in iPTH from baseline to Week 52. Differences between treatment groups were also compared. Results: In Population 1, iPTH decreased from baseline to Week 52 in the SFOH group (-25.3 pg/ml) but increased in the SEV group (89.8 pg/ml) (p = 0.02). In Population 2, iPTH increased to a similar extent in both treatment groups. In Population 3, iPTH concentrations in both treatment groups decreased to a similar degree (-29.6 and -11.4 pg/ml for SFOH and SEV, respectively; p = 0.87). Conclusions: In contrast with SEV, SFOH did not appear to impact the iPTH-lowering effect of oral VDRAs.

Prevalence and risk factors of vascular calcification in pre-dialysis patients with Balkan endemic nephropathy

Vascular calcifications (VC) are common in patients with chronic kidney disease and present one of manifestations of mineral and bone disorders in these patients. The aim of this pilot study was to examine the prevalence and risk factors of VC in pre-dialysis patients with Balkan endemic nephropathy (BEN) and other kidney diseases. The study involved 32 pre-dialysis patients, 15 with BEN and 17 with other kidney diseases. All the patients underwent an interview, objective examination, routine laboratory analyses and measurement of serum concentration of intact parathyroid hormone (iPTH), 25-hydroxyvitamin D3 [25(OH)D3] and osteopontin. VCs in iliac, femoral, radial, and digital arteries were evaluated and Adragao VC score was calculated. The samples of radial artery were collected during the first creation of an arteriovenous fistula, and expression of osteocalcin, bone morphogenic protein-2 osteopontin, and matrix Gla-protein in arterial wall were examined. Patients with BEN were significantly older (71.1 ± 6.1 vs. 54.7 ± 11.1 years), but they had significantly lower systolic and mean blood pressure (95.7 ± 13.2 mmHg vs. 104.3 ± 7.4 mmHg) and lower serum concentration of phosphorus (1.32 ± 0.36 mmol/l vs. 1.65 ± 0.35 mmol/l) and cholesterol (4.3 ± 1.1 mmol/l vs. 5.2 ± 0.8 mmol/l) than patients with other kidney diseases. Mean VC score was significantly lower in patients with BEN than in those with other kidney diseases (2.8 ± 1.7 vs. 4.6 ± 1.8; p = 0.009), but expression of four examined proteins in arterial wall differed insignificantly between the two groups. VC score correlated significantly with serum concentrations of cholesterol, triglycerides (positively), and iPTH (negatively). Pre-dialysis BEN patients had a significantly lower mean score of VC than patients with other kidney diseases.

Dietary calcium intake influences the relationship between serum 25-hydroxyvitamin D3 (25OHD) concentration and parathyroid hormone (PTH) concentration

ObjectivesTo investigate whether dietary calcium intake will modify the relationship between serum 25-hydroxyvitamin D3 (25OHD) with intact serum parathyroid hormone (PTH) concentrations in apparently healthy Indian adolescents.Study designCross-sectional study.Setting and...

Parathyroid Hormone Levels in Healthy Children and Adolescents

Background: Parathyroid hormone (PTH) is important in the assessment of calcium metabolism disorders. However, there are few data regarding PTH levels in childhood and adolescence. Aim: The aim of this study was to determine PTH levels in a large group of healthy children and adolescents. Patients and Methods: We retrospectively evaluated PTH levels in 1,580 healthy Caucasian children and adolescents (849 females, 731 males, aged 2.0-17.2 years) with 25-hydroxyvitamin D [25(OH)D] levels ≥30 ng/ml. All subjects with genetic, endocrine, hepatic, renal, or other known diseases were excluded. Results: The serum intact PTH concentration (median and inter-quartile range) was 23.00 (15.00-31.60) pg/ml. In our population, the mean 25(OH)D value was 34.27 ± 4.12 ng/ml. The median PTH concentration in boys was 23.00 (15.00-32.00) pg/ml, whereas in girls it was 23.10 (15.00-31.10) pg/ml. However, in girls, PTH levels significantly increased in the age group of 8.1-10.0 years compared to the age group of 2.1-4.0 years (p < 0.0001), whereas in boys it significantly increased in the age groups of 10.1-12.0 years (p < 0.0001) and 12.1-14.0 years (p < 0.0001), leading to the hypothesis of a relationship between PTH level and pubertal and bone growth spurts. Conclusions: PTH levels in healthy children and adolescents covered a narrower range than the adult values. Obtaining reference values of PTH in childhood and adolescence could aid in the estimation of appropriate values of bone metabolites.

Primary hyperparathyroidism due to atypical vertically long cystic adenoma.

SummaryParathyroid cystic adenomas are often misdiagnosed as thyroid cysts and routine preoperative diagnostic tools, such as ultrasonography (US) or 99m technetium-sestamibi (99mTc-MIBI) scans, cannot clearly distinguish between these entities. We present a 67-year-old hypercalcemic woman with a cervical cystic lesion who had negative sestamibi scan results. Her laboratory data indicated primary hyperparathyroidism (serum calcium concentration 14.0 mg/dl, phosphate concentration 2.3 mg/dl, and intact parathyroid hormone (PTH) concentration 239 pg/ml). The cervical US and computed tomography scans revealed a large and vertically long cystic mass (12×11×54 mm). A mass was located from the upper end of the left thyroid lobe to the submandibular region and was not clearly distinguishable from the thyroid. For preoperative definitive diagnosis, we carried out a parathyroid fine-needle aspiration (FNA) and PTH assay (PTH–FNA) of liquid aspirated from the cyst. The intact PTH–FNA concentration was 1.28×106 pg/ml, and the patient was diagnosed with primary hyperparathyroidism due to a cystic mass. She underwent a left upper parathyroidectomy and her serum calcium and intact PTH concentration immediately decreased to normal levels. This report describes the usefulness of PTH–FNA for localizing and differentiating an atypical functional parathyroid lesion from nonfunctional tissue in primary hyperparathyroidism.Learning points Cystic parathyroid lesions, even in the case of elevated PTH levels, can produce negative results in 99mTc-MIBI scans.Preoperative diagnosis of parathyroid cysts detectable on US is possible by parathyroid FNA and PTH assay (PTH–FNA) of liquid aspirated from the cyst, if malignancy is not suspected. PTH–FNA could be helpful in the differential diagnosis of an equivocal cervical tumor.