iPTH Levels Research Articles

#5653 MEASURABLE IMPROVEMENT IN ABD WITH SMALL CHANGE IN HD SETTING

Abstract Background and Aims Majority of the patients with chronic kidney disease on hemodialysis (CKD HD) have various bone-related pathologies covered under one clinical entity chronic kidney disease – mineral bone disorders (CKD-MBD). One of the most common is the adynamic bone disease (ABD).1 Published data are showing that changes of calcium level in HD fluid might improve the ABD.2,3 Our aim was to assess whether the lowering of the calcium in dialysis fluid will improve the ABD in our HD patients. Method Prospective study was conducted in a single HD centre in a period of 12 months (01.10.2020 until 30.09.2021), with further 6 months follow up. One hundred thirty three HD patients were screened, 64 patients of them had ABD (iPTH <150 ng/ml). 53 patients were enrolled who met the inclusion criteria (age >18 years, and HD vintage >90 days) and 50 completed the study, during which the only phosphate binder used was calcium based. The calcium level content in the dialysis fluid was changed from various calcium content level (1.5 mmol/L; 1.75 mmol/L) and set to 1.25 mmol/L in the enrolled patients. Laboratory parameters were followed each month and the level of iPTH trimonthly. Results Data from 50 patients was collected and analysed, 50.9% (n=27) males. The average age of the cohort was 69.31 years (±12.49), average HD vintage was 51.94 months (±43.82). Average HD time was 254.8 minutes (±14.71) with average blood pump 393.4 ml/min (±44.38). At study end, the iPTH level was significantly changed (p=.00001), from 67.48 ng/ml (±32.85) to 150.38 ng/ml (±92.96). 24 out of 50 patients (48%) had iPTH level >150 ng/ml, p=.00001. Calcium level changed slightly from 2.27 mmol/L (±0.15) to 2.25 mmol/L (±0.18), p=.25. The phosphate level changed from 1.29 mmol/L (±0.49) to 1.55 mmol/L (±0.48), p=.004. The alkaline phosphatase level significantly changed (p=.00002), from 82.61 IU/L (±49.5) to 118.71 IU/L (±50.23). Patients who had iPTH level >150 ng/ml at the study end had level of calcium of 2.2 mmol/L (±0.16), p=.17 compared to patients who had iPTH level <150 ng/ml (level of calcium of 2.31 mmol/L ±0.18; p= .43). There was improvement in the level of phosphate and alkaline phosphatase; 1.31 mmol/L (±0.46) vs. 1.6 mmol/L (±0.46), p=.002 and 82.57 IU/L (±57.22) vs. 130.83 IU/L (±60.24), p= .004, accordingly. Diabetes mellitus (DM) had insignificant impact on ABD in the patient cohort. 66.7% of the patients with DM (n=10) and 40% of the patients without DM (n=14) reached iPTH >150 ng/ml at study end. Intergroup comparison showed significance only in the level of calcium, DM group calcium=2.16 mmol/L (±0.1); non DM group calcium=2.29 mmol/L (±0.1); p=.01. Additionally, at study end, Karnofsky score was higher in patients with iPTH >150 ng/ml, 76.09% (±13.05); p=.009. Patients who did not reach iPTH >150 ng/ml (n=26) were further followed up for 6 months, and 10 of them reached iPTH >150 ng/ml. Conclusion Indirectly minor change in HD setting, as lowering the calcium level in dialysis fluid in a period of more than 12 months, might improve the adynamic bone disease. Presence of diabetes did not showed significant impact on ABD. However, Karnofsky score showed significant improvement, and exercise may also improve ABD in HD patients. These findings might be used as recommendation in low and middle-income countries in which pharmacological treatments for ABD are limited and/or unavailable.

#5586 EFFICACY OF ABLATION OF PARATHYROID AUTOGRAFTS FOR RECURRENT HYPERPARATHYROIDISM AFTER TOTAL PARATHYROIDECTOMY AND DELTOID AUTO TRANSPLANTATION

Abstract Background and Aims TPDI is the treatment of choice for patients with severe hyperparathyroidism who have failed medical therapy in our centre. The auto-transplantation of parathyroid tissue in the deltoid reduces the risk of permanent hypoparathyroidism. However, there is a risk of recurrent hyperparathyroidism from the implanted parathyroid tissue. Traditionally, these autografts are removed surgically in the event of recurrent hyperparathyroidism exposing the patients to the risk of permanent hypoparathyroidism. We attempted radiologically guided ablation of the implanted tissue to allow near but not complete ablation of the tissue. We aim to report our experience in using this technique to treat patients with recurrent hyperparathyroidism following TPDI. Method This is a single centre retrospective study of 9 patients who are on regular dialysis and underwent ablation of their deltoid parathyroid implants at Singapore General Hospital between May 2020 to July 2022. Baseline demographic data, as well as biochemistry results including intact parathyroid hormone (iPTH), serum calcium, phosphorus and alkaline phosphatase (ALP) levels were retrieved from electronic medical records and analysed. We define successful procedure as achieving 2 out of the following 3 criteria: i. >50% drop in iPTH level at 3 months, ii. correction of hypercalcemia at 3 months, iii. off calcimimetic at 3 months Results A total of 9 patients underwent ablation of their parathyroid deltoid implants, of which 8 (89%) had thermal ablation and 1 (11%) had cryoablation. 1 patient required a repeat procedure within 3 month as only 50% of the implanted tissue were targeted instead of the intended 80% and another patient had a repeat procedure >3 month after initial unsuccessful procedure. The median age of patients undergoing this procedure was 60 years (IQR 60, 66) and majority were female (5/9, 55.5%). 8 out of 9 patients were on haemodialysis. 7 out of 9 patients (78%) had a successful procedure based on our definition. 6 patients (67%) had a >50% reduction of iPTH at 3 month, 6 patients (67%) were off calcimimetic at 3 months and out of the 5 patients who were hypercalcemic pre procedure, 4(80%) patients had normalisation of hypercalcemia at 3 months. 3 patients (33%) had iPTH < 2x upper limit of normal with only 1 out of the 3 patient requiring high dose oral calcium replacement at 3 months. Pre ablation levels of PTH decreased from 191.87 ± 93.52 pmol/L to 99.77 ± 111.007 pmol/L (P = 0.773) 1 day after ablation and 92.450 ± 70.235 pmol/L (P = .0450) at 1 month and 91.25 ± 81.25 (P = .024) pmol/L at 3 months. Serum calcium levels decreased from 2.48 mmol/L ± 0.286 pre ablation to 2.11 mmol/L ± 0.322 1 day post ablation (P = 0.007) and remained 2.28 mmol/L ± 0.403 (P = .122) at 3 months post ablation. Serum ALP levels decreased from 478 ± 292.00 pre ablation to 238 ± 157 at 3 months post ablation. There were no re-admissions and no immediate post procedure complications in all patients. 4 out of 9 patients (44%) required intravenous calcium replacement post- procedure during the same admission. Limitations of this study are the relatively short follow-up duration and the small number of patients. 2 out of the 9 patients were lost to follow up at 3 months. Conclusion Ablation of deltoid parathyroid autografts may be a safe and effective minimally invasive procedure to manage recurrent hyperparathyroidism and minimising the risk of permanent hypoparathyroidism. However, further studies with larger sample sizes and longer follow up duration would be prudent to confirm our findings

#4993 EFFECT OF ETELCALCETIDE TREATMENT ON ERYTHROPOIESIS-STIMULATING AGENTS (ESAS) REQUIREMENT IN HEMODIALYSIS PATIENTS: A SINGLE CENTER STUDY

Abstract Background and Aims Anemia is a common consequence of advanced chronic kidney disease (CKD). There are various causes of renal anemia like decreased production of and resistance to Erythropoietin, shortened survival of red blood cells and chronic blood loss. Secondary hyperparathyroidism is a potential cause of renal anemia in CKD patients due to direct effect on Erythropoietin synthesis, red cell survival and bone marrow fibrosis [1]. There are several reports of the beneficial effect of treatment of hyperparathyroidism on hemoglobin (Hb) levels. Etelcalcetide is a novel intravenous calcimimetic used for the treatment of secondary hyperparathyroidism in hemodialysis patients. However, there are very few reports of Etelcalcetide's effect on anemia management in hemodialysis patients. We aimed to study the effect of Etelcalcitide on ESAs requirement in our hemodialysis cohort. Method This is a retrospective study in Al Wakra Hospital hemodialysis unit conducted on patients with uncontrolled secondary hyperparathyroidism who needed to be started on Etelcalcetide. Mean Hb and mean ESAs dose were calculated for a period of 6 months before and 6 months after starting Etelcalcetide, while iPTH levels were measured at the beginning and 6 months after starting Etelcalcetide. Inclusion criteria: hemodialysis patients who are on Etelcalcetide for at least 6 months. Exclusion criteria: Patients’ age < 18 years, hemodialysis duration < 12 months and patients with acute blood loss. Results Out of 94 hemodialysis patients, 26 (27.6%) were on Etelcalcetide. 2 patients were excluded, one for acute hematuria and the other for erosive gastritis. 24 patients were included (13 females and 11 males). Mean age of the patients was 58.7 years. 15 patients were on Darbepoetin, 8 on Erythropoietin and 1 patient was switched from Darbepoetin to Erythropoietin due to poor response. There was no significant difference in mean Hb levels for all the patients before and after starting Etelcalcetide (10.6 g/dl and 10.8 g/dl, respectively). Out of 24 patients, 19 had reduction while 5 had increase in ESAs dose requirement. In total, the mean reduction of ESAs dose for all the patients was 17.3%. There was a mean of 33.4% reduction in ESAs requirement for the 19 patients while a mean of 44% increase in the requirement for the 5 patients. Mean iPTH for the cohort at the time of starting Etelcalcetide and 6 months after was 1036 pg/ml and 473 pg/ml respectively. The mean reduction of iPTH for those who had decreased ESAs requirement was 58% while it was 38.8% for those who had increased ESA requirement. Conclusion This study showed that control of severe secondary hyperparathyroidism with Etelcalcetide was associated with reduction in ESAs requirement in hemodialysis patients. The more the control of hyperparathyroidism, the more the reduction of ESAs requirement. These findings were observed also in a one case report [2]. We believe that our study has one of the largest number of patients to show such an observation, however larger controlled studies are needed to confirm these preliminary findings in the improvement of anemia after treatment of hyperparathyroidism by Etelcalcetide.

#4465 NO DIFFERENCES IN ALL-CAUSE OR CARDIOVASCULAR MORTALITY BETWEEN DIALYSATE CALCIUM OF 1.25 AND 1.50 MMOL/L: RESULTS FROM A EUROPEAN HEMODIALYSIS COHORT

Abstract Background and Aims The appropriate prescription of dialysate calcium (DCa) concentration for hemodialysis (HD) patients is debated and guidelines are inconsistent. We investigated the association between DCa and all-cause, cardiovascular mortality and sudden cardiac death (SCD). Moreover, we examined the association between serum dialysate calcium gradient (SCa-DCa) and the study outcomes. Method In this historical cohort study, we included adult incident HD patients registered in the clinical database EuCliD® with dialysis initiation between January 1, 2010, and June 30, 2017 (recruitment period) who survived for at least 6 months after starting dialysis (grace period). We observed patients’ outcomes for up to 2 years after the end of the grace period (Figure 1). We categorized patients into 2 groups according to the prescribed DCa in the last 3 months of the grace period (ascertainment period): 1.25 (DCa 1.25) or 1.50 mmol/l (DCa 1.50). We calculated hazard ratio (HR) with 95% confidence intervals (CI) for all study outcomes with Cox Regression. The fully adjusted model included age, sex, ethnicity, diabetes mellitus, cardiovascular disease, liver disease, cancer, vascular access, treatment time, Kt/V, total ultrafiltered volume per session, serum hemoglobin, serum albumin, calcium containing phosphate binders, active vitamin D, Cinacalcet. We added country indicators as random effects. The SCa-DCa (in mEq/l) was calculated as (albumin-correct serum calcium (in mg⁄dl) × 0.5) – (DCa (in mmol/l) × 2) (1). Results We included 12,897 patients with DCa 1.25 and 26,989 patients with DCa 1.50 from 22 countries. The median age was 65 years and the percentage of men was 61% in both groups. In the unadjusted model, patients treated with DCa 1.50 had higher risk of all-cause mortality compared to those treated with DCa 1.25 (HR 1.07 [95% CI 1.01-1.12]. However, this association was not robust when adjusting for potential confounding (HR 1.04 [95% CI 0.97-1.10]). Similarly, we found no evidence of significant adjusted association between DCa and cardiovascular mortality (HR 1.01 [95% CI 0.92-1.11]). We observed a significant adjusted lower association between DCa 1.50 and SCD (HR 0.78 [95% CI 0.65-0.94]). We found significant associations between larger SCa-DCa gradient and all outcomes: all-cause (HR 1.16 per 1 mEq/L increase [95% CI 1.09-1.24]), cardiovascular mortality (HR 1.23 [95% CI 1.12-1.35]) and SCD (HR 1.69 [95% CI 1.41-2.03]). To explore the contribution of gradient components to patients’ risk, we included both DCa and serum calcium level (SCa) in the models. We observed significant associations with all outcomes and SCa, but not with DCa and the interaction between them. In a subgroup analysis of patients with iPTH levels below 130 pg/ml (n = 7,438), we did not find any significant association between DCa and the outcomes. Conclusion In this observational study, no differences in all-cause or cardiovascular mortality were observed with the prescription of DCa 1.50 as compared to 1.25 after adjustment for confounders, whereas the risk of SCD appeared to be lower in the group of DCa 1.50. The association between the SCa-DCa gradient and outcomes appears to be predominantly related to the effect of SCa.

Potential indicators for hyperparathyroidism progression: Calcium, phosphorus, alkaline phosphatase, 25 hydroxyvitamin D and hemoglobin

Purpose: To compare the differences in perioperative biochemical indices between patients with primary hyperparathyroidism (PH) and secondary hyperparathyroidism (SH).
 Methods: One hundred and ten patients with hyperparathyroidism who were treated in The Affiliated Hospital of Chengde Medical University, from June 2016 to April 2021, were enrolled and divided into two groups, viz, PH group (50 patients) and SH group (60 patients). Automatic biochemical analyzer was used to determine the levels of calcium, phosphorus, alkaline phosphatase and 25-hydroxyvitamin D, while hemoglobin was determined by liquid chromatography coupled with tandem mass spectrometry in the perioperative period.
 Results: Compared to PH group, SH group had higher levels of indicators (p < 0.05). There were significant differences in body mass index (BMI), somatic cell index and blood albumin in patients from 18 to 70 years (p < 0.05). BMI and blood albumin increased significantly with age (p < 0.05). The complication rate was higher in SH than PH group (p < 0.05). The scores of pruritus and bone pain of patients after surgery were lower than those before the operation (p < 0.05). Blood calcium levels increased significantly with age, while ALP and iPTH levels decreased significantly (p < 0.05). SH group showed lower scores of physiological, emotional, social, and cognitive functions than PH group (p < 0.05).
 Conclusion: Patients with PH and SH have differences in perioperative biochemical indicators. Furthermore, the levels of calcium, phosphorus, alkaline phosphatase, 25 hydroxyvitamin D, and hemoglobin may be used as indicators of disease progression, and this may facilitate the development of suitable therapeutic measures.

Postoperative hypoparathyroidism after thyroid operation and exploration of permanent hypoparathyroidism evaluation.

To investigate the risk factors for hypoparathyroidism, discuss the prevention of postoperative hypoparathyroidism, and explore permanent postoperative hypoparathyroidism evaluation (PPHE). A total of 2,903 patients with thyroid nodules were treated between October 2012 and August 2015. Serum calcium and intact parathyroid hormone (iPTH) levels were measured at 1 day, 1 month, and 6 months postoperatively. The incidence and management of hypoparathyroidism were analyzed. The PPHE was established based on the risk factors and clinical practice. A total of 637 (21.94%) patients developed hypoparathyroidism, and 92.15% of them had malignant nodules. The incidence rates of transient and permanent hypoparathyroidism were 11.47% and 10.47%, respectively. The iPTH level was lower in patients with malignant nodules who underwent total thyroidectomy (TT) and central-compartment neck dissection (CND). These factors were independently associated with the recovery rate of parathyroid function. The formula for PPHE is as follows: {iPTH} + {sCa} + {surgical procedure} + {reoperation} + {pathologic type}. A scoring system was developed, and we scored low, middle, and high risk of permanent postoperative hypoparathyroidism as 4-6, 7-9, and 10-13, respectively. The differences in the recovery rates of parathyroid function in several risk groups were statistically significant (p < 0.001). Simultaneous TT and CND is a risk factor for hypoparathyroidism. The reoperation is not associated with hypoparathyroidism. Identification of parathyroid glands in situ and preservation of their vascular pedicles are key factors in managing hypoparathyroidism. PPHE can forecast the risk of permanent postoperative hypoparathyroidism well.

A PROSPECTIVE STUDY OF POST RENAL TRANSPLANT MINERAL BONE DISORDER: A SINGLE CENTER EXPERIENCE

To evaluate sequential changes in biochemical bone parameters, parathyroid hormone (iPTH), and vitamin D levels over a period of 24 weeks after renal transplantation, we studied 52 patients (41 males, with a mean age of 31.98.) who underwent their first renal transplantation without a past history of parathyroid surgery or fractures. Serum calcium, phosphorus, albumin, Serum iPTH and vitamin D levels were measured before transplant, then at 2, 4, 12 and 24 weeks post transplantation. Serum calcium showed a significant increase from 2 to 12 weeks after transplantation, followed by a slight decline until 24 weeks. At the end of 12 and 24 weeks, 6 (11.53%) and 2 (3.8%) patients had hypercalcemia respectively. At the end of 12 weeks only 15.38% (8) patients had hypocalcemia and no patient had hypocalcemia at the end of 24 weeks. Serum phosphorus showed significant decline in the first 4 weeks post transplantation. At the end of 24 weeks 21.2% still had hypophosphatemia. iPTH levels declined rapidly in the first 4 weeks of post transplant period and there after decline slowly till the end of 24 weeks. Baseline iPTH and vitamin D3 levels did not correlate with persistent HPT. Hypovitaminosis D was seen in 16 (30.7%), 8 (15.3 %) and 11 (21.1%) patients at pretransplant, 12, and 24 weeks post transplant respectively. Unlike most studies in literature our patient population experienced lower prevalence of post transplant hypercalcemia, Hypovitaminosis D, and hyperparathyroidism which may have resulted from younger study population and shorter dialysis vintage.

Early clinical observation of supra-hemodiafiltration with endogenous reinfusion in the treatment of uremic pruritus.

To evaluate the clinical efficacy of supra-hemodiafiltration with endogenous reinfusion (Supra-HFR) for pruritus in uremic maintenance hemodialysis (HD) patients and explore the possible mechanism. This study prospectively included 60 patients with uremia who underwent maintenance hemodialysis and developed pruritus. Patients were randomly divided into a study group (30 cases) and a control group (30 cases). Patients in the study group underwent dialysis once a week with Supra-HFR and twice a week with HD. The group received HD dialysis 3 times a week. Visual analog scales (VAS) scores, 5-D itch scale scores, and 12-Item Pruritus Severity Scale (12-PSS) were used to evaluate the itching degree of patients. Quality of life was assessed using KDTA and SF-36 scores. Blood levels of hypersensitive C-reactive protein, calcium ion (Ca2+), phosphorus ion (P3+ ), free parathyroid hormone (iPTH), and β2-microglobulin (β2-MG) were compared between the two groups before treatment and at follow-up 24 weeks after treatment. Before treatment, there was no significant difference in VAS, 5-D itch scale, and 12-PSS score between the study group and the control group (all p > 0.05). After 24 weeks of treatment, the VAS score of the study group (2.82 ± 0.91) was significantly lower than that of the control group (7.47 ± 1.32, p < 0.001), the 5-D itch scale score of the study group (9.47 ± 2.34) was significantly lower than that of the control group (18.53 ± 4.02, p < 0.001), the 12-PSS score of the study group (11.20 ± 1.81) was significantly lower than that of the control group (16.47 ± 2.09, p < 0.001). KDTA of the study group (64.17 ± 8.07 vs. 47.83 ± 13.46, p < 0.001) and SF-36 scores (65.37 ± 6.28 vs. 55.90 ± 14.28, p = 0.002) were significantly higher than that in the control group. The levels of hs-CRP, P3+ , iPTH, and β2-MG in the study group after treatment were lower than those before treatment, and lower than those in the control group after treatment (all p < 0.05). The Supra-HFR can effectively reduce the itching symptoms of uremia patients and improve their quality of life.

Relationships between blood bone metabolic biomarkers and anemia in patients with chronic kidney disease

Introduction Blood bone metabolic biomarkers are noninvasive indices for evaluating metabolic bone diseases. We investigated the relationships between blood bone metabolic biomarkers and anemia in chronic kidney disease (CKD) patients and analyzed the effects of parathyroidectomy (PTX) on the above indices. Methods In this cross-sectional study, 100 healthy controls and 239 CKD patients, including 46 secondary hyperparathyroidism (SHPT) patients with PTX, were enrolled. Moreover, a prospective study was conducted in which 28 PTX patients were followed up. The degree of anemia was classified as mild, moderate, or severe based on the tertiles of hemoglobin (Hb) levels of the anemic CKD patients, with cutoff values of 83 g/L and 102 g/L. Bone metabolic biomarkers, including calcium (Ca), phosphorus (P), intact parathyroid hormone (iPTH), fibroblast growth factor 23 (FGF23), and α-klotho, were tested. Results The mean estimated glomerular filtration rate (eGFR) in CKD patients was 25.7 ± 36.0 ml/min/1.73 m2, and 84.10% of CKD patients had anemia. The baseline Hb levels in the mild, moderate, and severe anemia subgroups were 110.86 ± 5.99 g/L, 92.71 ± 5.96 g/L, and 67.38 ± 10.56 g/L, respectively. CKD patients had higher adjusted Ca, P, alkaline phosphatase (ALP), iPTH, and FGF23 levels and lower α-klotho levels than controls. Baseline adjusted Ca, P, iPTH, and α-klotho levels were associated with Hb levels in CKD patients. Blood adjusted Ca, P, and iPTH levels were correlated with anemia severity. After PTX (median interval: 6.88 months), anemia and high blood adjusted Ca, P, iPTH, and FGF23 levels were ameliorated, while α-klotho levels were increased. Conclusions Blood adjusted Ca, P, iPTH, and α-klotho levels were correlated with Hb levels in CKD patients. Correction of bone metabolic disorders may be a therapeutic strategy for anemia treatment.

Pattern of biochemical markers of mineral and bone disorders in kidney transplant recipients: real-world data

There is a lack of studies providing comprehensive data on the prevalence of mineral and bone disorders (MBD) laboratory abnormalities after kidney transplantation in Russia. to obtain real-world data on the prevalence of the main mineral abnormalities among kidney transplant recipients and to revise their concomitant MBD therapy. This cross-sectional study included 236 patients with successful kidney transplantation. Their serum intact parathyroid hormone (iPTH), total calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP) levels were measured. Only 6.2% of our cohort had all laboratory parameters within the target range, whereas persistent HPT along with hypercalcemia was noted in almost one third of the patients (31%). Normal iPTH levels were observed in 13% cases; 84% of the patients had hyperparathyroidism. The fraction of patients with target iPTH did not differ between the groups with normal and decreased estimated glomerular filtration rate (eGFR) (p=0.118). Hypercalcemia was observed in 29% cases. The serum P level varied significantly in groups with different eGFR (p&lt;0.0001), increasing with declining graft function. Furthermore, 40.7% of patients had ALP above the target range. While 123 patients received active vitamin D (alfacalcidol), 33 received monotherapy with inactive vitamin D (cholecalciferol). The control group consisted of 57 medication-naïve patients. The serum total Ca level varied significantly between the groups (p=0.0006), being higher in patients supplemented with cholecalciferol. The fraction of patients with normocalcemia was lowest in the cholecalciferol group (chi-square, р=0.0018). The prevalence of biochemical abnormalities after kidney transplantation is high. Alfacalcidol usage may be safer than using cholecalciferol to prevent hypercalcemia development.

Management of hypocalcemia following thyroid surgery in children.

Pediatric post-thyroidectomy hypocalcemia management varies significantly from hospital to hospital. The current study has two aims: first, we evaluate demographic data in all pediatric patients submitted to thyroid surgery in our Spanish tertiary hospital over 20 years; secondly, we describe the way that hypocalcemia was diagnosed and treated in that period and present a multidisciplinary protocol for perioperative management of this condition. This is a retrospective and observational study of all patients from 0 to 16 years old who underwent thyroid surgery from 2000 to 2020 at our institution. Demographic, surgical and electrolyte data were recorded from the electronic database. From 2000 to 2016, pediatric thyroid surgery at our institution was performed on 33 patients without a consistent approach or standard electrolyte management. A protocol for perioperative management of these patients was introduced in 2017, and applied to 13 patients. In 2019, the protocol was assessed and updated following a case of symptomatic hypocalcemia. From 2000 to 2016, 47 pediatric patients in all underwent thyroid surgery. We registered eight asymptomatic hypocalcemias. One child developed symptomatic hypocalcemia. Two patients have permanent hypoparathyroidism. Our incidence of general complications following thyroidectomy was low; hypocalcemia was the most prevalent. All the cases of hypocalcemia submitted to the protocol were identified early by iPTH measurements. Intraoperative iPTH levels and percentage drop from baseline could help stratify patients according to their risk of hypocalcemia. High risk patients require immediate postoperative supplementation, including calcitriol and calcium carbonate.

Prevalence and biochemical profile of adynamic bone disease in a hemodialysis population

Introduction and Aim: The number of patients suffering from end stage renal disease (ESRD) requiring dialysis has increased worldwide. Mineral bone disorders (MBD) commonly occur in ESRD patients. MBD is classified into high turnover bone disease and low turnover bone disease. Biochemical parameters play a key role in classifying MBD. Data on adynamic bone disease (ABD) in hemodialysis (HD) patients is sparse. The aim is to study the prevalence and biochemical profile of ABD in hemodialysis patients. Materials and Methods: This study was done as a cross sectional study in HD patients of a tertiary care hospital in South India. Baseline demographic data of the study population was collected. Biochemical data such as serum creatinine, blood urea nitrogen (BUN), bone markers for the diagnosis of CKD-MBD including serum calcium, phosphorus, alkaline phosphatase (ALP) and intact parathyroid hormone (iPTH) were collected. Based on the biochemical values, patients who had parameters suggestive of ABD were grouped as a separate cohort. Prevalence of ABD was calculated. Descriptive analysis of ABD cohort was done. Correlation of various bone markers with iPTH was carried out. Results: The study population (n=150) included 96 male (64%) and 54 female (36%) HD patients. The mean age of the study population is 54.54±14.81 years. 32.7% (n=49) of our study population had ABD. Serum calcium was found to be significantly higher in the ABD group. ALP and phosphorus were significantly lower in the ABD group. Conclusion: The prevalence of ABD in our HD population was 32.7%. The prevalence of ABD was the same among males and females. There was significant correlation of iPTH levels with ALP, calcium, and phosphorus levels.

Abstract #1412436: Nonclassical Presentation of Hypophosphatasia

Hypophosphatasia (HPP) is a rare genetic disorder characterized by impaired mineralization (calcification of bones and teeth). The signs and symptoms of HPP vary widely and can appear from birth to adulthood. We report a case of delayed bone fracture healing in the setting of hypophosphatasia. A 48-year-old male patient with a past medical history of vitamin D deficiency was seen in the outpatient clinic for low ALP levels. He had delayed wound healing involving the left clavicular and multiple rib fractures after a motor vehicle accident that occurred in 2012, which ultimately needed multiple surgeries requiring 1.5 years to fully heal/fuse. This involved placing and removing multiple plates and screws as well as bone grafts. He denied other fractures, skeletal deformities, or dental problems. He does have normal development and does not have short stature. He has a history of vitamin D deficiency and is on vitamin D 2000 units daily. He was found to have a family history remarkable with two sons with low ALP and vitamin D beginning in childhood. The older son was noted to have lost his teeth early at age 3-4 years, with no history of fractures. Musculoskeletal examination: no swelling noted, and no tenderness was noted but the patient did have a bone spur on the elbow, knee, and heel. He is able to ambulate without assistance and was found to have no other skeletal deformity. Laboratory findings: ALP 31 U/L (Normal 34-122). Bone-specific alkaline phosphatase: 5.6 ug/L (Normal 6.5-20.1). Vitamin D 25 OH level: 84 (on replacement therapy). Calcium: 9.2 mg/dl, phosphorus 3.5 mg/dl, iPTH levels 23 pg/ml. DXA scan: shows T values on the lumbar spine of -1.8, right hip of -1.4, and right neck of -1.9, consistent with osteopenia. We checked vitamin B6 level: 1087.7 nmol/L, consistent with hypophosphatasia. The patient then underwent genetic testing and is positive for ALPL gene mutation (heterozygous). Both his 2 sons are positive for ALPL gene mutation. We present a case of hypophosphatasia with nonclassical presentations, his mild symptoms likely from incomplete penetration. HPP causes pathogenic variants in ALPL gene. This gene provides instruction for making an enzyme called tissue non-specific alkaline phosphatase (TNSALP) which plays an essential role in the mineralization of the skeleton and teeth. Mutation in the ALP gene leads to the production of an abnormal version of TNSALP that cannot participate effectively in the mineralization process. There is currently no cure for hypophosphatasia, however human recombinant enzyme replacement therapy called asfotase alfa is now available.

Associated factors of osteoporosis and vascular calcification in patients awaiting kidney transplantation

IntroductionPretransplant osteoporosis and vascular calcification probably increase the risk of fractures and cardiovascular events after kidney transplantation. In the present study, we investigated the related risk factors of osteoporosis and vascular calcification among end-stage renal disease (ESRD) patients awaiting kidney transplantation.MethodsA total of 221 ESRD patients (age, 43.4 ± 14.3 years; 125 males and 96 females; median dialysis duration, 61.0 m) awaiting kidney transplantation were enrolled in this cross-sectional study. Serum levels of bone turnover markers and intact parathyroid hormone (iPTH) were analyzed from fasting morning blood samples. Dual-energy X-ray absorptiometry was used to measure bone mineral density (BMD). Vascular calcification was evaluated by lateral abdominal radiography and plain radiographic films of the pelvis and hands.ResultsThe osteoporosis prevalence was 27.6% in this cohort of kidney transplantation candidates, and the prevalence of vascular calcification was 51.1%. The related factors for osteoporosis and vascular calcification were similar and included older age, longer dialysis duration, parathyroid hyperplasia, and higher levels of iPTH and bone turnover markers. In the multivariable regression model, age and iPTH were independent risk predictors of both vascular calcification and osteoporosis. There were strong, positive correlations between iPTH and all bone turnover markers. The moderate and severe hyperparathyroidism (iPTH 600–1499 pg/ml and iPTH 1500 pg/ml) were related to reduced serum albumin and hemoglobin levels.ConclusionThe involvement of high iPTH levels in vascular calcification, osteoporosis, and malnutrition indicated the need of treating hyperparathyroidism early in patients awaiting kidney transplantation. Prospective studies are needed to further examine the utility of bone turnover markers.

Optimal Serum 25(OH)D Levels and Vitamin D Intake in Korean Postmenopausal Women.

Vitamin D plays a crucial role in regulating the growth and maintenance of the musculoskeletal system. Postmenopausal women are vulnerable to bone fractures because of the decrease in bone mineral density (BMD). Therefore, this study aimed to identify the determinants that influence BMD and the 25(OH)D levels in Korean postmenopausal women. This study collected general and dietary intake information, measured biochemical indices, and conducted BMD tests in 96 postmenopausal women residing in a metropolitan area in Korea. This study analyzed factors that influenced serum 25-hydroxyvitamin D (25(OH)D) and BMD, as well as the correlation between the intact parathyroid hormone (iPTH) and serum 25(OH)D levels. The serum 25(OH)D levels increased by 0.226 ng/mL in the summertime, 0.314 ng/mL in the wintertime, and 0.370 ng/mL on annual average when vitamin D intake rose by 1 µg/1000 kcal. When the serum 25(OH)D levels were ≥18.9 ng/mL, the iPTH levels did not rapidly increase. To maintain the serum 25(OH)D levels at ≥18.9 ng/mL, a daily vitamin D intake of ≥13.21 µg was required. Consequently, consuming vitamin D-fortified foods or vitamin D supplements is necessary to improve both bone health and vitamin D nutritional status.

The effects and safety of high dose vitamin D3 in hemodialysis patients.

Different studies have shown that hemodialysis patients require higher doses of Vitamin D3 (VD3) than the general population to achieve satisfactory replenishment. This study aims to assess the safety of such practice and its benefits on some of the parameters of Chronic Kidney Disease- Mineral and Bone Disorder (CKD-MBD). A single-center clinical trial assessing the benefits of high dose VD3 in hemodialysis patients. The dose of VD3 (300,000 IU) was administered orally and monthly from April to December 2020 (9 months) at the dialysis unit. The data analyzed were blood levels of calcium, phosphorus, alkaline phosphatase, 25(OH)D, 1,25(OH)2D and intact parathyroid hormone (iPTH) done every three months. We could recruit a cohort of 23 patients. Blood levels of 25(OH)D increased significantly in 82.6% of the patients to above 30 ng/ml. A similar effect was observed with 1, 25(OH)2D levels. iPTH levels decreased significantly when levels of 25(OH)D exceeded 30ng/ml at the end of the nine months. Vitamin D serum levels were typically measured immediately before the next monthly dose was administered. Blood levels of calcium, phosphorus, and alkaline phosphatase were stable during the study period. No events of hypercalcemia were reported, and no patient discontinued the monthly VD3 supplementation. Monthly administration of a high dose of VD3 over a long period of nine months in hemodialysis patients was found to be safe and beneficial in VD3 replenishment. It also allowed a significant decrease in iPTH levels. Further studies are warranted to identify the therapeutic target level of 25(OH)D in hemodialysis patients, allowing beneficial effects on iPTH.

Association of vitamin D metabolites with arteriovenous fistula function in hemodialysis patients: A single center study.

Arteriovenous fistula (AVF) is a primary dialysis vascular access commonly used for maintaining hemodialysis (MHD) patients. Vitamin D (VD) is a fat-soluble steroid hormone that is closely related to vascular endothelial function. This study aimed to investigate the association between VD metabolites and AVF failure in patients undergoing HD. This study included 443 HD patients using AVF between January 2010 and January 2020. The AVF operations in these patients were newly created by the same physician. We analyzed the AVF patency rates using the chi-square test. Univariate and multivariate logistic regression analyses were performed to explore risk factors for AVF failure. Survival analysis was performed to explore AVF survival at different serum 25-hydroxyvitamin D (25(OH)D) concentrations. Logistic regression analyses showed that male sex; age; BMI; serum albumin, triglyceride, phosphorus, 25(OH)D, iPTH and hemoglobin levels, history of hypertension, CHD, diabetes, stroke, and antiplatelet drug use; and smoking habits were not risk factors for AVF failure. The failure incidence rates of AVF in subjects in the VD deficiency and non VD deficiency group were not statistically significant (25.0% vs. 30.8%, p=0.344). The AVF failure incidence rates at 1, 3, and 5 years in the patients with 25(OH)D levels more than 20 ng/mL were 26%, 29%, and 37%, respectively, and the one-year AVF failure incidence rates were 27% in the patients with 25(OH)D levels less than 20 ng/mL. In addition, the Kaplan-Meier analysis suggested that the no significant differences were noted when calculating the cumulative survival rates of AVF between the two groups within 50 months of AVF using. Our findings suggest that 25(OH)D deficiency is not associated with AVF failure incidence rates, and that 25(OH)D deficiency has no significant impact on long-term cumulative AVF survival rate.

Prediction model of recurrence after parathyroidectomy in secondary hyperparathyroidism

Objective:To quantitatively evaluate the risk of recurrence in patients with secondary hyperparathyroidism after parathyroidectomy. Methods:The clinical data of 168 patients who underwent parathyroidectomy（PTX） from June 2017 to May 2019 were collected. The prediction model was constructed by using Akaike information criterion（AIC） to screen factors. A total of 158 patients treated with PTX from June 2019 to September 2021 were included in the validation set to conduct external validation of the model in three aspects of differentiation, consistency and clinical utility. Results:The prediction model we constructed includes different dialysis methods, ectopic parathyroid gland, the iPTH level at one day and one month after surgery, the number of excisional parathyroid and postoperative blood phosphorus. The C index of external validation of this model is 0.992 and the P value of the Calibration curve is 0.886[KG0.5mm]1. The decision curve analysis also shows that the evaluation effect of this model is perfect. Conclusion:The prediction model constructed in this study is useful for individualized prediction of recurrence after PTX in patients with secondary hyperparathyroidism.

Relationship between serum iPTH and peritonitis episodes in patients undergoing continuous ambulatory peritoneal dialysis.

Peritonitis is considered as one of the most serious complications that cause hospitalization in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). There is limited evidence on the impact of the parathyroid hormone (PTH) on the first peritoneal dialysis (PD)-associated peritonitis episode. We aimed to investigate the influence of serum intact parathyroid hormone (iPTH) on peritonitis in patients undergoing PD. This was a retrospective cohort study. Patients undergoing initial CAPD from a single center in China were enrolled. The baseline characteristics and clinical information were recorded. The primary outcome of interest was the occurrence of the first PD-associated peritonitis episode. Five Cox proportional hazard models were constructed in each group set. In group set 1, all participants were divided into three subgroups by tertiles of the serum concentration of iPTH; in group set 2, all participants were divided into three subgroups based on the serum concentration of iPTH with 150pg/ml interval (<150, 150-300, and >300pg/ml). Hazard ratios and 95% confidence intervals (CIs) were calculated for each model. The multivariate linear regression analysis elimination procedure assessed the association between the clinical characteristics at baseline and the iPTH levels. Restricted cubic spline models were constructed, and stratified analyses were also conducted. A total of 582 patients undergoing initial PD (40% women; mean age, 45.1±11.5years) from a single center in China were recruited. The median follow-up duration was 25.3months. Multivariate Cox regression analysis showed that, in the fully adjusted model, a higher serum iPTH level (tertile 3, iPTH>300pg/ml) was significantly associated with a higher risk of PD-associated peritonitis at 3years [tertile 3: hazard ratio (HR)=1.53, 95%CI=1.03-2.55, p=0.03; iPTH>300pg/ml: HR=1.57, 95%CI=1.08-2.27, p=0.02]. The hazard ratio for every 100pg/ml increase in serum iPTH level was 1.12 (95%CI=1.05-1.20, p<0.01) in the total cohort when treating iPTH as a continuous variable. An elevated iPTH level was significantly associated with an increased risk of peritonitis in patients undergoing CAPD.

Evaluation of T helper17 as skeletal homeostasis factor in peripheral blood mononuclear cells and T helper cells of end-stage renal disease cases with impaired parathyroid hormone.

Chronic renal failure is mainly connected with high and low parathyroid hormone (PTH) levels and immunological impairments. The present study aimed to evaluate T helper 17 (Th17) cells as a crucial modulator of the immune system and skeletal homeostasis in hemodialysis patients with impaired intact PTH (iPTH). In this research, blood samples were taken from ESRD patients with high (> 300 pg/mL), normal (150-300 pg/mL), and low (< 150 pg/mL) serum intact parathyroid hormone (iPTH( levels (n = 30 in each group). The frequency of Th17 (CD4+ IL17+) cells was evaluated by flow cytometry in each group. The expression levels of Th17 cell-related master transcription factors, cytokines in peripheral blood mononuclear cells (PBMC), and Th cells, and the level of the mentioned cytokines were determined in the supernatant of PBMCs. The number of Th17 cells remarkably increased in subjects with high iPTH against low and normal iPTH. Also, RORɣt and STAT3 levels were significantly higher in high iPTH ESRD patients than in other groups in the expression of mRNA and protein levels. These findings are confirmed by evaluating the IL-17 and IL-23 in the supernatant of cultured PBMCs and isolated Th cells. Our findings indicated that increased serum PTH levels in hemodialysis cases may be involved in increasing the differentiation of CD4 + cells to Th17 cells in PBMC.