Planned parathyroidectomy: the new standard in hypercalcemic crisis

Objective

The study sought to determine the clinical features of hyperparathyroid-induced hypercalcemic crisis (HIHC) along with treatment options and outcomes.

Subjects and methods

This is a retrospective analysis of our historical cohort of patients with primary hyperparathyroidism (PHPT). Patients were divided in groups according to their calcium levels and clinical presentation. HIHC (group 1) was assumed when patients had high calcium levels and needed emergency hospitalization. Group 2 was composed of patients with calcium levels above 16 mg/dL or patients who needed hospitalization for classical PHPT symptoms. Group 3 was composed of clinically stable patients with calcium levels between 14 and 16 mg/dL, who were electively treated.

Results

Twenty-nine patients had calcium levels above 14 mg/dL. HIHC group had seven patients, and initial clinical measures had good response in two patients, moderate response in one patient, and poor response in four patients. All poor responders underwent immediate surgery, and one of them died due to HIHC complications. Group 2 had nine patients, and all were successfully treated during hospitalization. Group 3 had 13 patients, and all had a successful elective surgery.

Conclusion

HIHC is a life-threatening condition that requires fast clinical intervention. Surgery is the only definitive treatment and should be planned for all patients. Poor response to initial clinical measures should direct treatment toward surgery to avoid disease progression and clinical deterioration.

Levels of bioavailable, and free forms of 25(OH)D after supplementation with vitamin D3 in primary hyperparathyroidism

The 25 hydroxyvitamin D [25(OH)D] is the major metabolite for ascertaining vitamin D status, which circulates bound to a specific carrier (vitamin D-binding protein - VDBP). A portion that circulates unbound vary according to the VDBP genotype. This study evaluates the behavior of different forms of 25(OH)D, before and after supplementation with 14,000 IU of vitamin D3, weekly for 12 weeks, in individuals with primary hyperparathyroidism and controls. Fifty-six patients with active primary hyperparathyroidism (PHPT) and 64 paired controls (CTRL), not taking vitamin D3 for the last three months, were enrolled. The genetic isotypes of VDBP were determined to calculate bioavailable and free 25(OH)D. A p < 0.05 was considered significant. There were no statistical differences in free, bioavailable, and total 25(OH)D levels between PHPT and CTRL groups at baseline. The distribution of VDBP haplotypes 1s/1s, 1f/1f, 1s/1f, 2/2, 1s/2, and 1f/2 was similar between groups. After supplementation, all three forms of 25(OH)D proportionally increased within each group, although the percentage increment was lower in the PHPT group (p < 0.05). Total 25(OH)D is better correlated with PTH in the PHPT group than bioavailable and free 25(OH)D (r = -0.41; p < 0.05). The concentrations of total, free, and bioavailable 25(OH)D were similar in both PHPT and CTRL groups, and all forms increased proportionally after supplementation, although this increment percentage was higher in the CTRL group, with a subsequent reduction of PTH and AP. Total 25(OH)D correlated better with PTH than other forms, suggesting no advantages in measuring free or bioavailable 25(OH)D in these situations.

Surgery for primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a hypercalcemic disorder that occurs when one or more parathyroid glands produces excessive parathyroid hormone (PTH). PHPT is typically treated with surgery, and it remains the only definitive therapy, whose techniques have evolved over previous decades. Advances in preoperative localization exams and the intraoperative PTH monitoring have become the cornerstones of recent parathyroidectomy techniques, as minimally invasive techniques are appropriate for most patients. Nevertheless, these techniques, are not suitable for PHPT patients who are at risk for multiglandular disease, especially in those who present with familial forms of PHPT that require bilateral neck exploration. This manuscript also explores other conditions that warrant special consideration during surgical treatment for PHPT: normocalcemic primary hyperparathyroidism, pregnancy, reoperation for persistent or recurrent PHPT, parathyroid carcinoma, and familial and genetic forms of hyperparathyroidism.

Definition and management of very high fracture risk in women with postmenopausal osteoporosis: a position statement from the Brazilian Society of Endocrinology and Metabolism (SBEM) and the Brazilian Association of Bone Assessment and Metabolism (ABRASSO)

Several drugs are available for the treatment of osteoporosis in postmenopausal women. Over the last decades, most patients requiring pharmacological intervention were offered antiresorptive drugs as first-line therapy, while anabolic agents were considered a last resource for those with therapeutic failure. However, recent randomized trials in patients with severe osteoporosis have shown that anabolic agents reduce fractures to a greater extent than antiresorptive medications. Additionally, evidence indicates that increases in bone mineral density (BMD) are maximized when patients are treated with anabolic agents first, followed by antiresorptive therapy. This evidence is key, considering that greater increases in BMD during osteoporosis treatment are associated with a more pronounced reduction in fracture risk. Thus, international guidelines have recently proposed an individualized approach to osteoporosis treatment based on fracture risk stratification, in which the stratification risk has been refined to include a category of patients at very high risk of fracture who should be managed with anabolic agents as first-line therapy. In this document, the Brazilian Society of Endocrinology and Metabolism and the Brazilian Association of Bone Assessment and Metabolism propose the definition of very high risk of osteoporotic fracture in postmenopausal women, for whom anabolic agents should be considered as first-line therapy. This document also reviews the factors associated with increased fracture risk, trials comparing anabolic versus antiresorptive agents, efficacy of anabolic agents in patients who are treatment naïve versus those previously treated with antiresorptive agents, and safety of anabolic agents.

Trabecular Bone Score (TBS) in Primary Hyperparathyroidism (PHPT): A Useful Tool?

Primary Hyperparathyroidism (PHPT) often leads to bone loss, even in its asymptomatic presentations. Trabecular Bone Score (TBS) is a method to assess the trabecular bone structure of the spine. This study aimed to evaluate TBS measurements combined with Dual X-ray Absorptiometry (DXA) values in the search for more accurate bone fragility risk assessment among PHPT patients. From 2017 to 2019, patients diagnosed with PHPT (n = 64), before surgery, were invited to participate in this study. Bone mineral density (BMD) by DXA at the lumbar spine, total hip, femoral neck, distal third radius, and TBS were determined in patients and controls (n = 63). The vertebral fracture was defined using the Genant method in vertebral images by DXA and vertebral fracture assessment (VFA). Patients and controls did not differ in age, sex, menopausal status, or body mass index (BMI). The PHPT patients presented significantly lower BMD values than the controls in all sites evaluated. The TBS measurements were also statistically lower in PHPT patients than controls (mean TBS PHPT = 1.233 vs TBS controls = 1.280, p = 0.044). Osteoporosis was observed in 50% of PHPT patients and 26.6% of controls (p = 0.02). However, lumbar spine T-Score < -2.5 was observed only in 21.8% of PHPT patients. Vertebral fractures were detected in nine individuals (14%) from the PHPT group and four (6.3%) in the controls (p = 0.24). The TBS area under the curve (AUC) was higher than DXA AUC in all sites, for vertebral fracture assessment. The TBS AUC was significant in the PHPT group (0.75, 95% CI 0.62 - 0.88, p = 0.02) and not significant in the DXA analysis. The ROC curve showed that TBS values < 1.187 are associated with a significantly higher risk of vertebral fracture among PHPT patients (p = 0.02). The TBS used as a complement to DXA measurements is a useful tool which may better assess fragility risk among PHPT patients.

Total, Free and Bioavailble 25 OH D and Bone Disease in Primary Hyperparathyroidism

Background: Low levels of vitamin D 25OHD are frequently described in PHP patients. The aim of this study was to evaluate bone parameters and vitamin D status in PHP patients and controls. Methods: Prior to surgery, 64 PHP patients and 63 healthy matched control subjects regarding age, gender and body mass index were enrolled in this study along 18 months. 25OHD and PTH were measured using Roche® Immunoassays. Bone mineral density (BMD) by dual X-ray absorptiometry (DXA) (Hologic QDR 4500) and TBS (InSight™) were determined in all patients and controls. Distribution of total, bioavailable and free (calculated) 25OH and its correlation with TBS and DXA in both groups was evaluated. DBP (vitamin D binding protein) SNPs genetic analysis was performed by ABI 7500 real time PCR System. None of the patients and controls were taking vitamin D supplements before the study. Results: PHP patients had lower BMD values than controls in all sites (p<0.01). TBS measurements were also reduced in PHP patients compared to controls, as expected (1233 vs 1280, p=0.04). There was no statistical difference in free, total and bioavailable 25OHD measurements between the PHP and the control group, mean±SD: 3.4±1.7 vs 3.1±1.7 pg/mL (p=0.44), 22.6± 6.1 vs 20.6± ng/dL (p=0.13) 1.53±0.66 vs 1.41±0.61 ng/mL (p=0.28), respectively. Likewise, there was no statistical difference in DBP haplotypes 1s/1s, 1f/1f, 1s/1f, 2/2, 1s/2, 1f/2 analysis between groups. There was no correlation with 25OHD and DXA measurements in both groups. However, total 25OHD presented statistical significant correlation with TBS measurements in the PHP group (r=0.28; p=0.02) and total, free and bioavailable 25OHD measurements with TBS in the control group (r=0.42; r=0.42; r=0.43; p<0.01). Conclusion: Vitamin D status correlates with TBS, but not with DXA, highlighting the relation of the vitamin D with the microarchitecture bone parameters in both PHP patients and controls. However, this correlation was more evident among controls than in PHP patients, spotlighting the primary hyperparathyroidism effects in bone.

SAT-395 Correlations Between Biochemical Parameters and Trabecular Bone Score (TBS) in Primary Hyperparathyroidism (PHP) Patients

Background: Vitamin D deficiency is common among PHP patients. While data are limited, some studies suggest that vitamin D deficiency may exacerbates skeletal disease in PHP. TBS is a software-based method for assessment of trabecular bone structure of the spine, based on analysis of pixels obtained in dual energy x-ray absorptiometry (DXA) images. The aim of this study was to evaluate TBS, vitamin D status, clinical and laboratorial measurements in a PHP group of patients in a search for a more accurate bone fragility test for risk assessment in this group of patients.

Methods: From June/2017 to January/2019, patients who met the criteria for PHP diagnosis were included in this study. Control group was composed by age and sex-matched healthy individuals. Overall, 64 PHP and 63 controls were enrolled. Bone mineral density (BMD) measured by DXA (Hologic QDR 4500) at the lumbar spine, total hip, femoral neck, and TBS values (InSight™) were determined in both groups. Total and ionized calcium, PTH, 25-hydroxyvitamin D (25(OH)D), creatinine, alkaline phosphatase, P1NP and CTX were measured. None were in use of Vitamin D supplementation.

Results: As expected, PHP patients had lower BMD values than controls in all sites (p<0.0001). TBS measurements were also reduced in PHP patients compared to controls (1233 vs 1280, p=0.0444). TBS values were inversely correlated with total calcium (CaT) and phosphorus measurements were positively correlated in the PHP patients. 25(OH)D measurements didn’t differ between groups (PHP 22.5 vs. controls 19.8 ng/mL, p=0.1699). There was a positive correlation between 25(OH)D and TBS in both PHP and controls (r= 0,3088, p= 0,0138 and r= 0,3708, p= 0,003 respectively). Considering individuals with vitamin D deficiency (25(OH)D levels <=20 ng/mL), a negative correlation between TBS and CaT measurements among PHP patients (r= -0,4391, p=0,0172) was observeed, while in controls there was a positive correlation between TBS and 25(OH)D (r= 0,3504, p= 0,0362).

Conclusion: Serum total calcium presents negative correlation and phosphorus a positive one with TBS in PHP patients. We also found a correlation between TBS and 25(OH)D, both in PHP and in controls. 25(OH)D <=20 ng/mL is an independent risk factor determining degraded TBS among PHP patients and controls.

SAT-405 Trabecular Bone Score (TBS) in Primary Hyperparathyroidism (PHP): A Useful Tool?

Background: PHP is a common disorder, and regardless of being an asymptomatic entity, often leads to bone loss and osteoporosis. TBS is a software-based assessment method of trabecular bone structure of the spine based on the analysis of pixels in dual energy x-ray absorptiometry (DXA) images. The aim of this study was to evaluate TBS measurements in combination with DXA values by searching for more accurate bone fragility risk assessment among PHP patients.

Methods: From June/2017 to January/2019, all patients who met the criteria for PHP diagnosis prior to surgery were selected to take part in this study. Control group was composed by non-family related healthy volunteers. Bone mineral density (BMD) by DXA (DXA; Hologic QDR 4500) at the lumbar spine, total hip, femoral neck, distal third of the non-dominant radius and TBS values by InSight were determined in 64 PHP patients and 63 controls. Total and ionized calcium, PTH, 25-hydroxyvitamin D (25(OH)D), creatinine, alkaline phosphatase, P1NP and CTX were measured in all patients and control group.

Results: Primary hyperparathyroidism patients presented significant lower BMD values in all evaluated sites compared to controls. TBS measurements were also statistically different among PHP patients and controls (mean TBS PHP=1233 vs TBS controls= 1280, p=0.044). Patients and controls didn’t differ in age, sex, menopausal state or BMI (body mass index). Osteoporosis diagnosis by DXA analysis was observed in 50% of PHP patients and in 26.6% of controls. Self-reported or image-diagnosed fracture occurred in 15 PHP (23.4%) patients and in 11 (17.5%) controls. Among these fractures, vertebral fracture account for 9 (14%) in PHP group and 4 (6.3%) in controls. ROC curve analysis showed that the TBS value &lt; 1187 is associated to significant high risk of vertebral fracture (sensibility 87.5%, specificity 67.3%) among PHP patients.

Conclusion: TBS, used as a complement to DXA measurements, is a useful tool to better assess fragility risk among PHP patients.

Prediction of bone mass changes after successful parathyroidectomy using biochemical markers of bone metabolism in primary hyperparathyroidism: is it clinically useful?

OBJECTIVE

To measure type 1 serum amino-terminal propeptide procollagen (P1NP) and type 1 cross-linked C-terminal telopeptide collagen (CTX) before parathyroidectomy (PTX) in PHPT patients, correlating these measurements with bone mineral density (BMD) changes.

SUBJECTS AND METHODS

31 primary hyperparathyroidism (HPTP) were followed from diagnosis up to 12-18 months after surgery. Serum levels of calcium, parathyroid hormone (PTH) vitamin D, CTX, P1NP, and BMD were measured before and 1 year after surgery.

RESULTS

One year after PTX, the mean BMD increased by 8.6%, 5.5%, 5.5%, and 2.2% in the lumbar spine, femoral neck (FN), total hip (TH), and distal third of the nondominant radius (R33%), respectively. There was a significant correlation between BMD change 1 year after the PTX and CTX (L1-L4: r = 0.614, p < 0.0003; FN: r = 0.497, p < 0.0051; TH: r = 0.595, p < 0.0005; R33%: r = 0.364, p < 0.043) and P1NP (L1-L4: r = 0,687, p < 0,0001; FN: r = 0,533, p < 0,0024; TH: r = 0,642, p < 0,0001; R33%: r = 0,467, p < 0,0079) preoperative levels. The increase in 25(OH)D levels has no correlation with BMD increase (r = -0.135; p = 0.4816). On linear regression, a minimum preoperative CTX value of 0.331 ng/mL or P1NP of 37.9 ng/mL was associated with a minimum 4% increase in L1-L4 BMD. In TH, minimum preoperative values of 0.684 ng/mL for CTX and 76.0 ng/mL for P1NP were associated with a ≥ 4% increase in BMD.

CONCLUSION

PHPT patients presented a significant correlation between preoperative levels of turnover markers and BMD improvement 1 year after PTX.

Experience with a third-generation parathyroid hormone assay (BIO-PTH) in the diagnosis of primary hyperparathyroidism in a Brazilian population

OBJECTIVE

To evaluate the usefulness of a third-generation PTH assay in the diagnosis of primary hyperparathyroidism (PHPT).

SUBJECTS AND METHODS

Forty-one PHPT patients (4 men and 37 women) with 61.2 ± 10.9 (mean ± SD) years, were studied and had PTH levels measured with two different methods using the same immunochemiluminescent assay plataform (Elecsys 2010 System, Roche). We compared a second-generation assay (I-PTH) with a third-generation PTH assay (Bio-PTH). Two populations of 423 and 120 healthy adults with serum 25OHD levels above 25 ng/mL were used to define normal values in the I-PTH and Bio-PTH assays respectively.

RESULTS

Normal PTH values based in the healthy adults population were 24.2-78.0 pg/mL for the I-PTH assay and 19.9-58.5 pg/mL for Bio-PTH assay. In PHPT patients, PTH values ranged from 67 to 553 pg/mL (median: 168 pg/mL) using the I-PTH assay and from 55 to 328 pg/mL (median: 111 pg/mL) using the Bio-PTH assay. Results obtained with the Bio-PTH assay were significantly lower (p < 0.0001, Wilcoxon). In general I-PTH and Bio-PTH showed highly significant correlation (r = 0.952, p < 0.0001). Passing-Bablok analysis gave a regression equation of Bio PTH = 13.44 + 0.59 x intact PTH. PHPT patients had 25OHD levels ranging from 4 to 36 ng/mL (mean 16.2 ng/mL); 35 subjects (85.3%) had values bellow 25 ng/mL.

CONCLUSION

Our results demonstrate that both second and third generation PTH methods are strongly correlated in PHPT patients and control subjects. Lower results with Bio-PTH tests are expected in function of the assay specificity determined by the amino-terminal antibody used.

Parathyroid responsiveness during hypocalcemia after total parathyroidectomy and autotransplantation in patients with renal hyperparathyroidism

INTRODUCTION

Hyperparathyroidism is a frequent complication of chronic kidney disease (CKD). Total parathyroidectomy (PTX) with parathyroid tissue autotransplantation (AT) is a treatment option in those individuals that do not respond to clinical management.

OBJECTIVE

To evaluate grafted parathyroid tissue response during induced hypocalcemia among CKD patients who underwent total PTX with AT.

METHODS

Eighteen patients with renal hyperparathyroidism were submitted to total PTX with parathyroid AT selected by stereomicroscopy between April and October 2008. Eleven (eight with successful kidney transplantation, 2 in peritoneal dialysis and 1 in hemodialysis) were clinically stable and eligible for testing. Hypocalcemia was induced using sodium bicarbonate infusion in 5 healthy controls and in patients 6-12 months after surgery.

RESULTS

Among controls, hypocalcemia elicited a major rise in intact PTH (iPTH) levels 4 minutes after bicarbonate infusion. In patients, a significant decrease in ionized calcium concentration was observed [from 1.17 ± 0.12 to 1.09 ± 0.11 mean (± SE) mmol/L] in the 4th minute (p < 0.001) illustrating the nadir point. In the 10thminute, ionized calcium did not show a statistical increase compared to the 4th minute (p = 0.451). The iPTH levels ranged from 34.8 ± 18.6 to 34.1 ± 18.8 pg/mL (similar values between base line and 4thminute p = 0.087) and did not change in the 10th minute (33.3 ± 19,6 pg/ mL p = 0.693).

CONCLUSION

Among CKD patients tested 6-12 months after surgery, grafted parathyroid tissue revealed a blunted secretory capacity during bicarbonate induced hypocalcemia with no changes in iPTH levels.

Autotransplant tissue selection criteria with or without stereomicroscopy in parathyroidectomy for treatment of renal hyperparathyroidism

Introduction

Several methods have been proposed to improve operative success in renal hyperparathyroidism.

Objective

To evaluate stereomicroscopy in parathyroid tissue selection for total parathyroidectomy with autotransplantation in secondary (SHPT)/tertiary (THPT) hyperparathyroidism.

Methods

118 renal patients underwent surgery from April of 2000 to October 2009. They were divided into two groups: G1, 66 patients operated from April of 2000 to May of 2005, with tissue selection based on macroscopic observation; G2, 52 patients operated from March of 2008 to October 2009 with stereomicroscopy for tissue selection searching for the presence of adipose cells. All surgeries were performed by the same surgeon. Patients presented SHPT (dialysis treatment) or THPT (renal-grafted). Follow-up was 12–36 months. Intra-operative parathyroid hormone (PTH) was measured in 100/118 (84.7%) patients.

Results

Data are presented as means. G1 included 66 patients (38 SHPT, 24 females/14 males; 40.0 years of age; 28 THPT, 14 females/14 males; 44 years of age). G2 included 52 patients (29 SHPT, 11 females/18 males; 50.7 years of age; 23 THPT, 13 females/10 males, 44.4 years of age). SHPT patients from G2 presented preoperative serum calcium higher than those of SHPT patients in G1 (p < 0.05), suggesting a more severe disease. Definitive hypoparathyroidism was found in seven of 118 patients (5.9%). Graft-dependent recurrence occurred in four patients, two in each group. All occurred in dialysis patients.

Conclusion

Stereomicroscopy in SHPT/THPT surgical treatment may be a useful tool to standardize parathyroid tissue selection.

Localization of ectopic and supernumerary parathyroid glands in patients with secondary and tertiary hyperparathyroidism: surgical description and correlation with preoperative ultrasonography and Tc99m-Sestamibi scintigraphy

Introdução

O hiperparatireoidismo é uma consequência metabólica esperada na doença renal crônica (DRC). Paratireoides (PT) ectópicas e/ou supranumerárias podem ser causa de falha cirúrgica nos pacientes submetidos à paratireoidectomia total (PTX).

Objetivo

Definir cirurgicamente a localização das PT, em pacientes com hiperparatireoidismo associado à DRC, correlacionar esses achados com os exames pré-operatórios.

Materiais e métodos

Foi conduzido um estudo retrospectivo com 166 pacientes submetidos à PTX. A localização das PT no intraoperatório foi registrada, sendo classificada como tópica ou ectópica. A localização pré-operatória, definida pela ultrassonografia (USG) e pela cintilografia Tc99m-Sestamibi (MIBI), foi comparada com aos achados cirúrgicos.

Resultados

Nos 166 pacientes, foram identificadas 664 PT. Foram classificadas como tópicas e ectópicas 577 (86,4%) e 91(13,6%) glândulas, respectivamente. Oito PT supranumerárias foram encontradas (7 tópicas e 1 ectópica). As localizações mais comuns de PT ectópicas foram as regiões retroesofágica e tímica. Associadas, a USG e a MIBI não identificaram 56 glândulas (61,5%) ectópicas. Entretanto, a MIBI foi positiva para 69,7% daquelas localizadas nas regiões tímicas e mediastinal.

Conclusão

A presença de glândulas ectópicas e supranumerárias em pacientes com hiperparatireoidismo associado à DRC é significativa. Os exames de imagem pré-operatórios não localizaram a maioria das glândulas ectópicas. A MIBI pode ter importância na identificação de PT nas regiões tímica e mediastinal.

Parathyroid carcinoma and hungry bone syndrome

We hereby report two patients with parathyroid carcinoma presenting extremely high calcium and PTH levels, severe bone disease, and palpable neck mass at diagnosis. They both underwent parathyroidectomy, and one of them evolved to lung metastasis. Important hypocalcemia was observed after surgery in both: after parathyroidectomy in one patient, and only after surgical removal of the metastasis in the other. Both required intravenous calcium replacement, thus revealing hungry bone syndrome (HBS). HBS usually reflects rapid mineralization after correction of hyperparathyroidism. The more severe the bone disease before surgery, the more prone the patient is to HBS after surgery. Despite being an unfavorable outcome, HBS state suggests that surgical removal of hypersecretory parathyroid tissue was accomplished. In this study, HBS was observed in both patients, who presented severe bone disease prior to surgery. HBS would be expected post-operatively in successful parathyroid carcinoma removal.

Intraoperative PTH cutoff definition to predict successful parathyroidectomy in secondary and tertiary hyperparathyroidism

In order to improve success rates in surgery of renal hyperparathyroidism, we evaluated intraoperative PTH (IOPTH) measurement utility.

Method

86 patients underwent total parathyroidectomy with intramuscular presternal autotransplantation from 04/2000 to 10/2009 and were followed for 26.5 months on average (prospective cohort). Patients were divided in secondary (SHPT) and tertiary hyperparathyroidism (THPT). SHPT group was composed by patients under dialysis treatment, THPT group included renal grafted ones. IOPTH (Elecsys-PTH-Immunoassay/Roche) was measured at anesthesia induction (IOPTH-0’) and 20 minutes (IOPTH-20’) after parathyroidectomy.

Results

80.2% (69/86) presented with 80% decrease or more in the IOPTH-20’ and all were cured. In 11/86 patients (12.7%), a lower IOPTH-20’ drop (70-79%) was observed, and 2 of them (18.1%) failed to cure. 6/86 (6.9%) patients presented IO-PTH-20’ decrease of less than 70%: two were cured, in three a supernumerary/ectopic parathyroid was found and removed, and in one of these six patients, surgery was finished after 4-gland excision and the patient failure to cure.

Conclusion

IOPTH-20’ decrease of 80% or more compared to IOPTH-0’ predicts cure in all renal patients throughout follow-up. A decay of less than 70% points to missed or hyperfunctioning supernumerary gland and is predictive of surgical failure in 66.6%. A marginal IOPTH drop of 70-79% leaves the decision whether or not surgery should be continued up to the experienced surgeon.

Parathyroid hormone: an early predictor of symptomatic hypocalcemia after total thyroidectomy

OBJECTIVE: The purpose of this study was to evaluate if the measurement of peri-operative parathyroid hormone (PTH) is able to identify patients with increased risk of developing symptoms of hypocalcemia. SUBJECTS AND METHODS: Forty patients who underwent total thyroidectomy were studied prospectively. Ionized serum calcium and PTH were measured after induction of anesthesia, one hour (PTH1) and one day after surgery (PTH24). Patients were evaluated for symptoms of hypocalcemia and treated with calcium and vitamin D supplementation as necessary. RESULTS: Symptomatic hypocalcemia developed in 16 patients. Symptomatic patients had significant lower PTH1 and greater drops in PTH levels. The selection of 12.1 ng/L as PTH1 level cutoff level divided patients with and without symptoms with 93.7% sensitivity and 91.6% specificity. The selection of 73.5% as the cutoff value for PTH decrease resulted in 91.6% sensitivity and 87.5% specificity. CONCLUSION: PTH1 levels and the drop in PTH levels are reliable predictors of developing symptomatic hypocalcemia after total thyroidectomy.

Analysis of the diagnostic presentation profile, parathyroidectomy indication and bone mineral density follow-up of Brazilian patients with primary hyperparathyroidism

Primary hyperparathyroidism is an endocrine disorder with variable clinical expression, frequently presenting as asymptomatic hypercalcemia in Western countries but still predominantly as a symptomatic disease in developing countries. The objective of this retrospective study was to describe the diagnostic presentation profile, parathyroidectomy indication and post-surgical bone mineral density follow-up of patients with primary hyperparathyroidism seen at a university hospital. We found 115 patients (92 women, median age 56 years) with primary hyperparathyroidism diagnosed during the last 20 years. We defined symptomatic patients based on the presence of any classical symptom affecting bone, kidney or the neuromuscular system. Surgical criteria followed the guidelines of the National Institutes of Health regarding asymptomatic primary hyperparathyroidism. Symptomatic patients and patients meeting surgical criteria for parathyroidectomy were 66 and 93% of the sample, respectively. Median calcium and parathyroid hormone values were 11.9 mg/dL and 189 pg/mL, respectively. After surgical treatment, 97% of patients were cured, with increases in bone mineral density of 19.4% in the lumbar spine and 15.7% in the femoral neck 3 years after surgery. Greater bone mass increases were detected in pre-menopausal women, men, and in symptomatic and younger patients, both in the lumbar spine and femoral neck. Our results support the previous findings of a predominantly symptomatic disease with a presentation profile that could be mainly related to a delayed diagnosis. Nevertheless, genetic and racial backgrounds, and nutritional factors such as calcium and vitamin D deficiency may play a role in the clinical presentation of primary hyperparathyroidism of Brazilian patients.

Utilidade da medida de PTH intra-operatório no tratamento cirúrgico do hiperparatiroidismo primário e secundário: análise de 109 casos

INTRODUÇÃO: A medida de PTH intra-operatório (PTH-IO) foi inicialmente descrita em 1988, sendo potencialmente útil na definição de sucesso após a paratiroidectomia. OBJETIVOS: Avaliar prospectivamente perfil de decaimento do PTH-IO e sua capacidade de prever sucesso cirúrgico no hiperparatiroidismo primário (HPP) e secundário à insuficiência renal (HPS). PACIENTES E MÉTODOS: 109 pacientes operados entre 06/2000 e 12/2004, sendo 33 HPP, 76 HPS (52 em diálise, 24 transplantados renais). PTH-IO: método imunométrico rápido (Elecsys-PTH/Immunoassay-Roche); tempo para resultado: 10 minutos. Coletas de sangue periférico nos tempos basal, 10 e 20 minutos pós-paratiroidectomia. RESULTADOS: HPP: queda média de PTH de 79,2% aos 10 minutos. HPS: queda média de PTH de 85,8% e 87,6% aos 10 minutos nos pacientes diálise e transplantados respectivamente. A cirurgia foi bem sucedida em todos, exceto em 2 pacientes (1 HPP, 1 HPS). Em ambos não houve queda PTH-IO, sendo constatado adenoma duplo no HPP e paratiróide ectópica no HPS. CONCLUSÃO: Medida PTH-IO fornece resultados confiáveis em tempo rápido, sendo capaz de discriminar persistência da doença se mantidos níveis elevados.

Changes in clinical and laboratory findings at the time of diagnosis of primary hyperparathyroidism in a University Hospital in São Paulo from 1985 to 2002

In contrast to most developed countries, most patients with primary hyperparathyroidism in Brazil are still symptomatic at diagnosis. However, we have been observing a change in this pattern, especially in the last few years. We evaluated 104 patients, 77 females and 27 males aged 11-79 years (mean: 54.4 years), diagnosed between 1985 and 2002 at a University Hospital. Diagnosis was made on the basis of clinical findings and of high total and/or ionized calcium levels, high or inappropriate levels of intact parathyroid hormone and of surgical findings in 80 patients. Patients were divided into three groups, i.e., patients diagnosed from 1985 to 1989, patients diagnosed from 1990 to 1994, and patients diagnosed from 1995 to 2002. The number of new cases diagnosed/year increased from 1.8/year in the first group to 6.0/year in the second group and 8.1/year in the third group. The first group comprised 9 patients (mean serum calcium +/- SD, 13.6 +/- 1.6 mg/dl), 8 of them (88.8%) defined as symptomatic. The second group comprised 30 patients (mean calcium +/- SD, 12.2 +/- 1.63 mg/dl), 22 of them defined as symptomatic (73.3%). The third group contained 65 patients (mean calcium 11.7 +/- 1.1 mg/dl), 34 of them symptomatic (52.3%). Patients from the first group tended to be younger (mean +/- SD, 43.0 +/- 15 vs 55.1 +/- 14.4 and 55.7 +/- 17.3 years, respectively) and their mean serum calcium was significantly higher (P < 0.05). All of symptomatic patients independent of group had higher serum calcium levels (12.4 +/- 1.53 mg/dl, N = 64) than asymptomatic patients (11.4 +/- 1.0 mg/dl, N = 40). Our data showed an increase in the percentage of asymptomatic patients over the years in the number of primary hyperparathyroidism cases diagnosed. This finding may be due to an increased availability of diagnostic methods and/or to an increased awareness about the disease.

Usefulness of a rapid immunometric assay for intraoperative parathyroid hormone measurements

Intraoperative parathyroid hormone (IO-PTH) measurements have been proposed to improve operative success rates in primary, secondary and tertiary hyperparathyroidism (PHP, SHP and THP). Thirty-one patients requiring parathyroidectomy were evaluated retrospectively from June 2000 to January 2002. Sixteen had PHP, 7 SHP and 8 THP. Serum samples were taken at times 0 (before resection), 10, 20 and 30 min after resection of each abnormal parathyroid gland. Samples from 28 patients were frozen at -70 C for subsequent tests, whereas samples from three patients were tested while surgery was being performed. IO-PTH was measured using the Elecsys immunochemiluminometric assay (Roche, Mannheim, Germany). The time necessary to perform the assay was 9 min. All samples had a second measurement taken by a conventional immunofluorimetric method. We considered as cured patients who presented normocalcemia in PHP and THP, and normal levels of PTH in SHP one month after surgery and who remained in this condition throughout the follow-up of 1 to 20 months. When rapid PTH assay was compared with a routine immunofluorimetric assay, excellent correlation was observed (r = 0.959, P < 0.0001). IO-PTH measurement showed a rapid average decline of 78.8% in PTH 10 min after adenoma resection in PHP and all patients were cured. SHP patients had an average IO-PTH decrease of 89% 30 min after total parathyroidectomy and cure was observed in 85.7%. THP showed an average IO-PTH decrease of 91.9%, and cure was obtained in 87.5% of patients. IO-PTH can be a useful tool that might improve the rate of successful treatment of PHP, SHP and THP.