Prevalence and risk factors for tertiary hyperparathyroidism in kidney transplant recipients.

BACKGROUND: Tertiary hyperparathyroidism after kidney transplantation has been associated with graft dysfunction, cardiovascular morbidity, and osteopenia; however, its true prevalence is unclear. The objective of our study was to evaluate the prevalence of and risk factors for tertiary hyperparathyroidism. METHODS: A prospective cohort of 849 adult kidney transplantation recipients (December 2008-February 2020) was used to estimate the prevalence of hyperparathyroidism 1-year post-kidney transplant. Tertiary hyperparathyroidism was defined as hypercalcemia (≥10mg/dL) and hyperparathyroidism (parathyroid hormone≥70pg/mL) 1-year post-kidney transplantation. Modified Poisson regression models were used to evaluate risk factors associated with the development of both persistent hyperparathyroidism and tertiary hyperparathyroidism. RESULTS: Among kidney transplantation recipients, 524 (61.7%) had persistent hyperparathyroidism and 182 (21.5%) had tertiary hyperparathyroidism at 1-year post-kidney transplantation. Calcimimetic use before kidney transplantation was associated with 1.30-fold higher risk of persistent hyperparathyroidism (adjusted prevalence ratio = 1.30, 95% CI: 1.12-1.51) and 1.84-fold higher risk of tertiary hyperparathyroidism (adjusted prevalence ratio = 1.84, 95% CI: 1.25-2.72). Pre-kidney transplantation parathyroid hormone ≥300 pg/mL was associated with 1.49-fold higher risk of persistent hyperparathyroidism (adjusted prevalence ratio = 1.49, 95% CI = 1.19-1.85) and 2.21-fold higher risk of tertiary hyperparathyroidism (adjusted prevalence ratio = 2.21, 95% CI = 1.25-3.90). Pre-kidney transplantation tertiary hyperparathyroidism was associated with an increased risk of post-kidney transplantation tertiary hyperparathyroidism (adjusted prevalence ratio = 1.71, 95% CI = 1.29-2.27), but not persistent hyperparathyroidism. Furthermore, 73.0% of patients with persistent hyperparathyroidism and 61.5% with tertiary hyperparathyroidism did not receive any treatment at 1-year post-kidney transplantation. CONCLUSION: Persistent hyperparathyroidism affected 61.7% and tertiary hyperparathyroidism affected 21.5% of kidney transplantation recipients; however, the majority of patients were not treated. Pre-kidney transplantation parathyroid hormone levels ≥300pg/mL and the use of calcimimetics are associated with the development of tertiary hyperparathyroidism. These findings encourage the re-evaluation of recommended pre-kidney transplantation parathyroid hormone thresholds and reconsideration of pre-kidney transplantation secondary hyperparathyroidism treatments to avoid the adverse sequelae of tertiary hyperparathyroidism in kidney transplantation recipients.

Combined Effects of Vitamin D Status, Renal Function and Age on Serum Parathyroid Hormone Levels.

Background: Vitamin D status and renal function are well-known independent predictors of serum parathyroid hormone (PTH) levels. We aimed to describe the combined effects of 25-hydroxy vitamin D (25(OH)D), glomerular filtration rate (GFR) and age on serum PTH levels across the whole clinical spectrum. Methods: We retrieved from our endocrinology center database all PTH measurement between 2012 and 2020 for which a simultaneous measurement of serum 25(OH)D, calcium and creatinine was available. Age, sex and diagnosis were available for all subjects. Intact PTH was measured using the same electrochemiluminescence assay. Results: There were 6,444 adults and 701 children without a diagnosis of hyper- or hypoparathyroidism or abnormal serum calcium levels. In adults with 25(OH)D≥12 ng/mL multiple regression models showed that serum PTH was negatively correlated with both 25(OH)D and GFR. Regression (-0.68 and -1.59 vs. -0.45 and -0.22 respectively), partial correlation (-0.16 and -0.35 vs. -0.12 and -0.10 respectively) and determination coefficients (0.14 vs. 0.031) were higher in CKD than in normal renal function. In subjects with 25(OH)D<12 ng/mL, GFR was the only significant predictor in those with CKD (ß-coefficient=-2.5, r=-0.55) and 25(OH)D was the only significant predictor in those with normal renal function (ß-coefficient=-2.05, r=-0.11). Increasing age was associated with higher PTH levels only in those with normal renal function and 25(OH)D≥12 ng/mL. Conclusions: We showed that declining vitamin D and renal function have additive effects on serum PTH in subjects without vitamin D deficiency. In vitamin D deficient subjects this dependency is stronger but is not additive anymore.

Vitamin D deficiency, secondary hyperparathyroidism and respiratory insufficiency in hospitalized patients with COVID-19.

PURPOSE: Hypovitaminosis D has emerged as potential risk factor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the general population with variable effects on the outcome of the coronavirus disease-19 (COVID-19). The aim of this retrospective single-center study was to investigate the impact of hypovitaminosis D and secondary hyperparathyroidism on respiratory outcomes of COVID-19. METHODS: Three-hundred-forty-eight consecutive patients hospitalized for COVID-19 at the IRCCS Humanitas Research Hospital, Rozzano, Milan (Italy) were evaluated for arterial partial pressure oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio, serum 25hydroxy-vitamin D [25(OH)D], parathyroid hormone (PTH) and inflammatory parameters at study entry and need of ventilation during the hospital stay. RESULTS: In the entire population, vitamin D deficiency (i.e., 25(OH)D values < 12 ng/mL) was significantly associated with acute hypoxemic respiratory failure at the study entry [adjusted odds ratio (OR) 2.48, 95% confidence interval 1.29-4.74; P = 0.006], independently of age and sex of subjects, serum calcium and inflammatory parameters. In patients evaluated for serum PTH (97 cases), secondary hyperparathyroidism combined with vitamin D deficiency was significantly associated with acute hypoxemic respiratory failure at study entry (P = 0.001) and need of ventilation during the hospital stay (P = 0.031). CONCLUSION: This study provides evidence that vitamin D deficiency, when associated with secondary hyperparathyroidism, may negatively impact the clinical outcome of SARS-CoV-2-related pneumonia.

Osteoporosis and Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD): Back to Basics.

Osteoporosis is defined as a skeletal disorder of compromised bone strength predisposing those affected to an elevated risk of fracture. However, based on bone histology, osteoporosis is only part of a spectrum of skeletal complications that includes osteomalacia and the various forms of renal osteodystrophy of chronic kidney disease-mineral and bone disorder (CKD-MBD). In addition, the label "kidney-induced osteoporosis" has been proposed, even though the changes caused by CKD do not qualify as osteoporosis by the histological diagnosis. It is clear, therefore, that such terminology may not be helpful diagnostically or in making treatment decisions. A new label, "CKD-MBD/osteoporosis" could be a more appropriate term because it brings osteoporosis under the official label of CKD-MBD. Neither laboratory nor noninvasive diagnostic investigations can discriminate osteoporosis from the several forms of renal osteodystrophy. Transiliac crest bone biopsy can make the diagnosis of osteoporosis by exclusion of other kidney-associated bone diseases, but its availability is limited. Recently, a classification of metabolic bone diseases based on bone turnover, from low to high, together with mineralization and bone volume, has been proposed. Therapeutically, no antifracture treatments have been approved by the US Food and Drug Administration for patients with kidney-associated bone disease. Agents that suppress parathyroid hormone (vitamin D analogues and calcimimetics) are used to treat hyperparathyroid bone disease. Antiresorptive and osteoanabolic agents approved for osteoporosis are being used off-label to treat CKD stages 3b-5 in high-risk patients. It has now been suggested that intermittent administration of parathyroid hormone as early as CKD stage 2 could be an effective management strategy. If confirmed in clinical trials, it could mitigate the retention of phosphorus and subsequently the rise in fibroblast growth factor 23 and may be beneficial for coexisting osteoporosis.

[Unusual cause of hypercalcemia in pregnancy]. / Ungewöhnliche Ursache einer Hyperkalzämie in der Schwangerschaft.

BACKGROUND: Neuroendocrine tumors (NET) diagnosed during pregnancy are extremely rare. This case report describes diagnosis and treatment of a metastasized pancreas NET that became symptomatic in the second trimester. CASE DESCRIPTION: A 33-year-old patient presented to the emergency department in the 19th week of pregnancy (WOP) with persistent diarrhea. Laboratory tests showed a pronounced hypercalcemia (3.53 mmol/l). Imaging revealed a mass in the pancreatic corpus/tail with extensive liver metastasis. Histologically, a NET (G2, SSTR-positive) with paraneoplastic parathormone-related-peptide secretion was found to be the cause of hypercalcemia. Under a treatment with octreotide, calcium values normalized and diarrhea stopped. After delivery of a healthy child (32.WOP via cesarean section) tumor progress was found. The pancreatic mass was resected completely, the liver metastases as far as possible. Postoperatively, in a CT scan, residual suspicious liver lesions could be found, and a palliative therapy with lanreotide was initiated. With this treatment, the patient has been asymptomatic for one year, and serum calcium remained normal. The child developed normally. DISCUSSION: This unusual case shows that even in extensively metastasized symptomatic NETs during pregnancy, there may be sufficient diagnostic and therapeutic options that allow for a continuation of pregnancy in close interdisciplinary cooperation under careful risk-benefit assessment for mother and child.

Data mining: Biological and temporal factors associated with blood parathyroid hormone, vitamin D, and calcium concentrations in the Southwestern Chinese population.

BACKGROUND: Parathyroid hormone (PTH) and vitamin D plays a major role in calcium (Ca) homeostasis and bone turnover. The purpose of this study was to assess which factors (sex, age, time of blood sampling, season of the year, temperature and sunshine hours (SHH)) had the greatest impact on plasma PTH, 25-OH-VitD, and Ca levels, and then whether these effects were clinically acceptable in a large number of Southwestern Chinese subjects. METHOD: The data was from West China Hospital Health Examination Center, Sichuan University from April 1, 2018 to June 30, 2019. A total of 18,664 physical examination subjects were included. PTH and 25-OH-VitD were measured by a Roche Cobas e 601, and Ca was measured by a Roche Cobas 8000. Linear regression models were used to assess correlations between PTH, 25-OH-VitD, Ca and the above factors. RESULTS: The concentrations of serum PTH in females were significantly higher than those in males, while the 25-OH-VitD and Ca were opposite. The concentration of PTH in data collection decreased in summer and increased in spring. The concentration of 25-OH-VitD decreases in spring and increases in autumn. PTH concentrations were negatively correlated with last month temperature and SHH, while 25-OH-VitD were opposite. Linear regression showed that season may be the main factor affecting serum PTH and 25-OH-VitD levels, and these effects were not clinically acceptable. CONCLUSION: In order to avoid influencing clinicians' investigation of suspected hyperparathyroidism and hypovitaminosis, reference intervals for PTH, 25-OH-VitD, and Ca should be established, taking into account sex, age and the season.

Anesthetic considerations in hyperparathyroid crisis: A case report.

INTRODUCTION: Hyperparathyroid crisis is a rare and potentially life-threatening complication of severe calcium intoxication. Parathyroidectomy is the only curative method for hyperparathyroid crisis. Several case reports and case series have been published on the medical and surgical treatments for hyperparathyroid crisis, however, few reports have focused on the associated perioperative anesthetic management. PATIENT CONCERNS: A 48-year-old Chinese woman presented with a 2-week history of nausea and vomiting and complained of mental status alteration including confusion and agitation in the 24 hours prior to her admission. She denied any history of past illness. Laboratory tests showed severe hypercalcemia crisis with a serum calcium level of 5.21 mmol/L and a serum intact parathyroid hormone level of > 5000 pg/mL. DIAGNOSIS: The diagnosis was hyperparathyroid crisis, acute kidney injury, acute liver injury, rhabdomyolysis, infection, and shock. INTERVENTIONS: She underwent initial management with aggressive intravenous fluid resuscitation, loop diuretic treatment, vitamin D supplement, intravenous bisphosphonates, and calcitonin therapy. However, her condition worsened, and she was transferred to the operating theater for a parathyroidectomy under general anesthesia. She was under general anesthesia and monitored with electrocardiogram, pulse oxygen saturation, continuous arterial blood pressure, central venous pressure and nasopharyngeal temperature. Cardiac output and stroke volume variation were monitored from the FloTrac system. After liberal fluid rehydration, circulatory support, cooling treatment and calcium supplement after tumor removal, her unstable vital signs gradually improved. OUTCOMES: After meticulous anesthetic management by the anesthesiologist and complete tumor resection by the surgeon, she survived this fatal disease. The patients was discharged on postoperative day 37 without any sequelae. LESSONS: Patients with hyperparathyroid crisis should undergo a thorough preoperative evaluation. Difficult airway, fluid depletion, multiple organ dysfunction, hypercoagulability, and concomitant diseases are the primary challenges in anesthetic management. After tumor removal, the serum calcium level should be monitored closely and calcium should be supplemented in a timely manner to prevent serious complications.

Selective parathyroid venous sampling in reoperative parathyroid surgery: A key localization tool when noninvasive tests are unrevealing.

BACKGROUND: Preoperative localization studies are essential for parathyroid re-exploration. When noninvasive studies do not regionalize the abnormal parathyroid gland, selective parathyroid venous sampling may be employed. We studied the utility of parathyroid venous sampling in reoperative parathyroid surgery and the factors that may affect parathyroid venous sampling results. METHODS: Patients with hyperparathyroidism and previous cervical surgery undergoing evaluation for reoperative parathyroidectomy over a 20-year period were identified. Patients with indeterminate or negative noninvasive studies underwent parathyroid venous sampling. Parathyroid hormone values were mapped with a ≥2-fold increase above peripheral signifying positive parathyroid venous sampling. These results were correlated with reoperative findings. RESULTS: Parathyroid venous sampling was positive in 113 of 140 (81%). Re-exploration occurred in 75 (66%). Parathyroid venous sampling correctly detected the region of abnormal glands in 58 (77%). With 1 gradient, 1 abnormal gland was found in 81%. With multiple gradients, 1 abnormal gland was found in 78%, most often at the site with the largest gradient. Eighty percent of patients who underwent reoperative parathyroidectomy were biochemically cured. CONCLUSION: Parathyroid venous sampling can guide parathyroid re-exploration when noninvasive localizing studies are indeterminate. Expectation of 1 versus multiple remaining glands was key in interpreting the results.

A Combination of Hemodialysis with Hemoperfusion Helped to Reduce the Cardiovascular-Related Mortality Rate after a 3-Year Follow-Up: A Pilot Study in Vietnam.

AIMS: Moderate to severe hyperparathyroidism (parathyroid hormone [PTH] concentrations ≥600 pg/mL) may increase the risk of cardiovascular problems and bone disease. We assume that a combination of hemodialysis with hemoperfusion may reduce the cardiovascular-related mortality rate in maintenance hemodialysis. SUBJECTS AND METHODS: From 625 maintenance hemodialysis patients, 93 people met with our inclusion criteria. Based on the level of serum PTH, the patients were divided into 2 groups: 46 patients who underwent a combination of hemodialysis and hemoperfusion (HD + HP group) for consecutive 3 years and 47 patients who used hemodialysis only (HD group). RESULTS: During 3 years of follow-up, the ratio of mortality was 4.3% in the HD + HP group which was significantly lower than in the HD group (17%), p = 0.049. Based on Kaplan-Meier analysis of cardiovascular-related mortality, patients in the HD group (red line) exhibited a significantly higher death rate compared to the HD + HP group (violet line) (log-rank test, p = 0.049). CONCLUSION: We demonstrated that a combination of hemodialysis and hemoperfusion for 3 years helped to reduce the cardiovascular-related mortality rate.

Normocalcaemic hyperparathyroidism and primary hyperparathyroidism: least significant change for adjusted serum calcium.

INTRODUCTION: The least significant change (LSC) is a term used in individuals in order to evaluate whether one measurement has changed significantly from the previous one. It is widely used when assessing bone mineral density (BMD) scans. To the best of our knowledge, there no such estimate available in the literature for patients with disorders of calcium metabolism. Our aim was to provide an estimate of the least significant change for albumin-adjusted calcium in patients with normocalcaemic hyperparathyroidism (NPHPT) and primary hyperparathyroidism (PHPT). METHODS: We used the within-subject standard deviatio calculated in a population of NPHPT and PHPT patients and multiplied it by 2.77. RESULTS: The LSC for NPHPT and PHPT were found to be 0.25 and 0.24 mmol/L, respectively (1.00 and 0.96 mg/dL). In clinical practice, the value of 0.25 mmol/L could be used. DISCUSSION: The least significant change given, could be used in two ways in these patients. First, it gives a range to which values are expected. This can provide some reassurance for the patient and the physician in cases of intermittent hypercalcaemia. Moreover, it can be a marker of whether an individual has an actual significant change of his calcium after parathyroid surgery.

Utility of blood tests in screening for metabolic disorders in kidney stone disease.

OBJECTIVES: To determine the clinical utility of blood tests as a screening tool for metabolic abnormalities in patients with kidney stone disease. SUBJECTS AND METHODS: Clinical and biochemical data from 709 patients attending the Oxford University Hospitals NHS Foundation Trust for assessment and treatment of kidney stones were prospectively collected between April 2011 and February 2017. Data were analysed to determine the utility of serum calcium, parathyroid hormone (PTH), urate, chloride, bicarbonate, potassium and phosphate assays in screening for primary hyperparathyroidism, normocalcaemic hyperparathyroidism, hyperuricosuria, distal renal tubular acidosis (dRTA) and hypercalciuria. RESULTS: An elevated serum calcium level was detected in 2.3% of patients. Further investigations prompted by this finding resulted in a diagnosis of primary hyperparathyroidism in 0.2% of men and 4.6% of women for whom serum calcium was recorded. An elevated serum PTH level in the absence of hypercalcaemia was detected in 15.1% of patients. Of these patients, 74.6% were vitamin D-insufficient; no patients were diagnosed with normocalcaemic hyperparathyroidism. Hyperuricosuria was present in 21.6% of patients and hypercalciuria in 47.1%. Hyperuricaemia was not associated with hyperuricosuria, nor was hypophosphataemia associated with hypercalciuria. No patient was highlighted as being at risk of dRTA using serum chloride and bicarbonate as screening tests. CONCLUSION: This study indicates that individuals presenting with renal calculi should undergo metabolic screening with a serum calcium measurement alone. Use of additional blood tests to screen for metabolic disorders is not cost-effective and may provide false reassurance that metabolic abnormalities are not present. A full metabolic assessment with 24-h urine collection should be undertaken in recurrent stone formers and in those at high risk of future stone disease to identify potentially treatable metabolic abnormalities.

Establish pre-clinical diagnostic efficacy for parathyroid hormone as a point-of-surgery-testing-device (POST).

Measuring the Parathyroid hormone (PTH) levels assists in the investigation and management of patients with parathyroid disorders. Rapid PTH monitoring is a valid tool for accurate assessment intraoperatively. Rapid Electro-Analytical Device (READ) is a point-of-care device that uses impedance change between target and capture probe to assess the PTH concentration in undiluted patient plasma samples. The aim of this work focuses on evaluating the analytical performance of READ platform to Roche analyzer as a prospective clinical validation method. The coefficient of variation (CV) for intra-assay imprecision was < 5% and inter-assay imprecision CV was < 10% for high (942 pg/mL) and low (38.2 pg/mL) PTH concentration. Functional sensitivity defined at 15% CV was 1.9 pg/mL. Results obtained from READ platform correlated well (r = 0.99) with commercially available clinical laboratory method (Roche Diagnostics) to measure PTH concentrations with a turn-around time of less than 15 min. Furthermore, the mean bias of 7.6 pg/mL determined by Bland-Altman analysis, showed good agreement between the two methods. We envision such a sensing system would allow medical practitioners to facilitate targeted interventions, thereby, offering an immediate prognostic approach as the cornerstone to delivering successful treatment for patients suffering from primary hyperparathyroidism.

Successful Use of Denosumab for Life-Threatening Hypercalcemia in a Pediatric Patient with Primary Hyperparathyroidism.

INTRODUCTION: Primary hyperparathyroidism (PHPT) is rare and usually symptomatic in children. There is no approved medication to lower serum calcium levels in this patient group. Denosumab is used in adult patients with osteoporosis and hyperparathyroidism. To our knowledge, only 1 case of denosumab treatment in a child with severe PHPT has been reported to date. CASE PRESENTATION: A 16-year-old female was referred to our clinic with symptoms including pathologic fractures, nausea, emesis, and progressive weight loss. At admission, her serum total calcium was 4.17 mmol/L (reference range 2.15-2.55), parathyroid hormone 2,151 pg/mL (15-65), and phosphate 1.07 mmol/L (1.45-1.78). Due to potentially life-threatening hypercalcemia, denosumab 60 mg subcutaneously was administered after obtaining informed consent. Serum calcium levels were reduced within 12 h of injection and the patient's condition rapidly improved, which allowed genetic testing to be done prior to surgery. A heterozygous mutation in the CDC73 gene was revealed, and a parathyroidectomy was performed on day 22 after denosumab administration. Morphological examination revealed solitary parathyroid adenoma. After surgery, hypocalcemia developed requiring high doses of alfacalcidol and calcium supplements. CONCLUSION: Our case supports the previous observations in adults that denosumab can be safely and effectively used as a preoperative treatment in patients with PHPT and severe hypercalcemia and shows that it may be used in pediatric patients.

18F-choline PET/4D CT in hyperparathyroidism: correlation between biochemical data and study parameters. / PET/TC 4D 18F-colina en el hiperparatiroidismo: correlación entre datos bioquímicos y parámetros del estudio.

BACKGROUND: Hyperparathyroidism (HPT) is characterised by increased levels of parathyroid hormone (HPT), surgical excision being the only definitive curative option. After establishing the need for surgery, it is essential to identify the parathyroid glands in the preoperative period to use a minimally invasive approach. Negativity and / or discrepancy in first-line studies (ultrasound and Tc-99m MIBI parathyroid scintigraphy) require more accurate images to reduce the likelihood of bilateral cervical exploration or reintervention. OBJECTIVES: a) To demonstrate the sensitivity of 18F-fluorocholine (18F-choline) positron emission tomography (PET)/4D computed tomography (4D CT) in HPT. b) To check whether there is a correlation between calcaemia and preoperative PTH versus size and early and late SUVmax (Standardized Uptake Value) of the gland, determined by 18F-choline PET/4D CT and c) to study the behaviour of parathyroid lesions with intravenous contrast (IV). MATERIAL AND METHODS: A total of 28 patients were included between 2016 and 2019 in a single institution. Prospective observational cohort study. Correlations were analysed using Pearson's coefficient for variables with normal distribution and Spearman (rho) for those with non-normal distribution. Anatomopathological analysis was the benchmark standard to determine sensitivity was. A p<.05 was interpreted as significant. STATA 13 software was used. RESULTS: Of the 28 patients who underwent 18F-choline PET/4D CT, 18 were operated. Of the 26 lesions diagnosed by 18F-choline PET/4D CT as suggestive of parathyroid lesions, 23 corresponded to glandular disease (adenoma or hyperplasia) establishing a sensitivity of 88.5%. There was a correlation between the patient's preoperative PTH and the maximum size of the gland on 18F-choline PET/4D CT. (Spearman=.66; p=.0014). The parathyroid lesions showed, in addition to IV contrast enhancement, distinctive behavioural characteristics identified as highly suggestive. CONCLUSIONS: 18F-choline PET/CT 4D is an anatomical and functional study with high sensitivity in patients with HPT with negative or discrepant first-line studies. Preoperative PTH showed a correlation with maximum gland size on 18F-choline PET/CT 4D. Parathyroid lesions behave in a highly suggestive way and are enhanced by IV contrast.

Moderators of the Association Between Serum Parathyroid Hormone and Metabolic Syndrome in Participants with Elevated Parathyroid Hormone: NHANES 2003-2006.

This cross-sectional study extracted data of 392 NHANES participants with elevated serum parathyroid hormone (PTH) concentrations from 2 cycles of the US National Health and Nutrition Examination Survey (NHANES) 2003-2006 and evaluated the association between serum (PTH) concentration and metabolic syndrome (MetS) to identify dietary and lifestyle factors that may modify that association. The primary outcome was MetS severity scores. Results of univariate linear regression analyses revealed that serum PTH concentrations correlated positively and significantly with MetS severity scores (ß=0.399, p=0.030). After adjusting for gender, age, race, and alcohol consumption, results of multivariate analysis revealed that increased serum PTH concentration correlated significantly with higher MetS severity scores (ß=0.413, p=0.045) in participants with moderate physical activity over the past 30 days. Serum PTH concentration also correlated significantly with higher MetS severity scores in participants with serum 25-hydroxyvitamin D deficiency (ß=0.456 and p=0.014), those without vitamin D supplementation (ß=0.524, p=0.028) and with higher protein intake (ß=0.586 and p=0.030). In conclusion, increased serum PTH concentration is associated with higher MetS severity scores in participants with elevated serum PTH at baseline. The association between PTH concentration and MetS severity is moderated by participants' physical activity levels, status of serum vitamin D, vitamin D supplementation, and daily protein intake.

Safety and Efficacy of a 3-Year Therapy With Cinacalcet in Persistent Hyperparathyroidism After Renal Transplant.

BACKGROUND: Persistent post-transplant hyperparathyroidism (PPTHP) can occur in 20% to 50% of renal transplant recipients. The aim of this study was to analyze safety and efficacy of long-term cinacalcet therapy in a group of renal transplant recipients with PPTHP. METHODS: A single center retrospective cohort study including renal transplant recipients, adults (>18 years old) with PPTHP and hypercalcemia. Inclusion criteria for cinacalcet therapy was increased parathormone levels (PTH > 65 pg/mL) associated with serum calcium >11.5 mg/dL any time after transplant or calcium >10.2 mg/dL within the first year after transplant. The follow-up period was 3 years. Demographic, laboratory data and adverse events were assessed. RESULTS: Forty-six patients were included, mean age of 50 ± 11 years old, majority of white race (60%), male (58%), with a pretransplant length on dialysis of 67 ± 34 months. Cinacalcet therapy was started 37 ± 40 months after transplant, and normal calcium levels were achieved after 6 months of therapy. PTH levels presented a steady reduction over time, reaching levels near normal after 36 months (317 ± 242 vs 145 ± 72 pg/mL, baseline × month 36, P < .05). Renal function remained stable over time (GFR > 60 mL/min/1.73 m2) and no acute rejection episodes were observed. Most common adverse events were mild gastrointestinal symptoms. In 6 patients (12.5%) treatment was interrupted due to adverse events. Only 1 case (2%) was classified as treatment failure. CONCLUSION: Cinacalcet therapy proved to be efficient for PPTHP and safe for graft and patient. Long-term treatment reduced PTH levels to near normal range.

Normocalcemic Hyperparathyroidism: Study of its Prevalence and Natural History.

CONTEXT: Normocalcemic hyperparathyroidism (NPHPT) is characterized by persistently normal calcium levels and elevated parathyroid hormone (PTH) values, after excluding other causes of secondary hyperparathyroidism. The prevalence of the disease varies greatly and the data on the natural history of this disease are sparse and inconclusive. OBJECTIVES: The objectives of this study are to describe the prevalence of NPHPT and its natural history in a referral population and to compare the variability of serum calcium with a group of patients with primary hyperparathyroidism (PHPT). DESIGN: A retrospective study was conducted over 5 years. SETTING: The setting for this study was a metabolic bone referral center. PATIENTS: A total of 6280 patients were referred for a bone mineral density measurement (BMD). MAIN OUTCOME MEASURES: The prevalence and natural history of NPHPT and variability of calcium were the main outcome measures. RESULTS: We identified NPHPT patients using data from the day of the BMD measurement. We excluded patients with low estimated glomerular filtration rate (eGFR) or vitamin D, or with no measurements available. Based on the evaluation of their medical files, we identified 11 patients with NPHPT (prevalence 0.18%). Only 4 patients had consistent normocalcemia throughout their follow-up, with only 2 also having consistently high PTH. None had consistently normal eGFR or vitamin D.Intermittent hypercalcemia was present in 7 of the 11 NPHPT patients. The mean adjusted calcium was found to be significantly lower in the NPHPT group compared with the PHPT group but higher than the control group. PTH was similar for NPHPT and PHPT. These 2 groups had similar variability in serum calcium. CONCLUSIONS: NPHPT patients often have episodes of hypercalcemia. We believe that NPHPT is a mild form of PHPT.