Cost-effectiveness analysis of three surgical approaches for parathyroidectomy in secondary hyperparathyroidism patients

Background

There are three main surgical treatment options for secondary hyperparathyroidism (SHPT): subtotal parathyroidectomy (sPTX), total parathyroidectomy with auto-transplantation (tPTX+AT), and total parathyroidectomy (tPTX). However, a debate regarding which of these surgical methods is optimal has been ongoing. Aim of this study is to compare medical costs and final outcomes associated with the three surgical approaches for the entire treatment duration, aiming to identify the most cost-effective surgical method.

Methods

Based on previous research data from domestic and international studies, as well as data from on-site surveys, TreeAge Pro 2022 software was used to construct a Markov model for the surgical treatment of SHPT patients. The model was run using data from the 2022 registered population of end-stage renal disease dialysis patients in China (1 million) as baseline cohort. Main indicators for this analysis are total cost, quality-adjusted life years, and incremental cost-effectiveness ratio (ICER). The study period is 10 years post-surgery, with a discount rate of 5% per year. Uncertainty in the model was assessed using one-way sensitivity analysis and probabilistic sensitivity analysis (PSA).

Results

The costs incurred by SHPT patients undergoing sPTX, tPTX, and tPTX+AT within 10 years post-surgery are $7042.54, $9983.00, and $11435.60, respectively, with total utilities generated being 13.23 QALYs, 18.76 QALYs, and 18.69 QALYs. Compared to sPTX, the incremental costs and incremental effects of tPTX and tPTX+AT are $2,924.71 and $4,456.66, with 5.53 QALYs and 5.46 QALYs, respectively. The ICER for tPTX and tPTX+AT groups are $532.13/QALY and $805.10/QALY, respectively, which are well below our set willingness-to-pay (WTP) threshold. Sensitivity analysis results indicate that varying any parameter within a certain range over the given time interval will not cause the ICER to exceed the WTP threshold and will not reverse the primary analysis results.

Conclusion

In the Chinese healthcare system, tPTX is considered the most cost-effective treatment for refractory hyperparathyroidism, when compared to tPTX+AT and sPTX.

Treatment for secondary hyperparathyroidism focusing on parathyroidectomy

Secondary hyperparathyroidism (SHPT) is a major problem for patients with chronic kidney disease and can cause many complications, including osteodystrophy, fractures, and cardiovascular diseases. Treatment for SHPT has changed radically with the advent of calcimimetics; however, parathyroidectomy (PTx) remains one of the most important treatments. For successful PTx, removing all parathyroid glands (PTGs) without complications is essential to prevent persistent or recurrent SHPT. Preoperative imaging studies for the localization of PTGs, such as ultrasonography, computed tomography, and 99mTc-Sestamibi scintigraphy, and intraoperative evaluation methods to confirm the removal of all PTGs, including, intraoperative intact parathyroid hormone monitoring and frozen section diagnosis, are useful. Functional and anatomical preservation of the recurrent laryngeal nerves can be confirmed via intraoperative nerve monitoring. Total or subtotal PTx with or without transcervical thymectomy and autotransplantation can also be performed. Appropriate operative methods for PTx should be selected according to the patients' need for kidney transplantation. In the case of persistent or recurrent SHPT after the initial PTx, localization of the causative PTGs with autotransplantation is challenging as causative PTGs can exist in the neck, mediastinum, or autotransplanted areas. Additionally, the efficacy and cost-effectiveness of calcimimetics and PTx are increasingly being discussed. In this review, medical and surgical treatments for SHPT are described.

Regulation of Renin Expression by Β1-Integrin in As4.1 Juxtaglomerular Line Cells

(1) Background: Renal dysfunction and hypertension are mutually aggravating factors; however, the details of their interaction remain unclear. In a study using renal tissue from diabetic rats, we found that β1-integrin, a cell-substrate adhesion molecule, is specifically phosphorylated in juxtaglomerular cells that secrete renin, a blood pressure regulator. (2) Methods: A mouse juxtaglomerular cell line (As4.1 cells) was used for the following experiments: drug-induced promotion of β1-integrin phosphorylation/dephosphorylation; knockdown of β1-integrin and the cell adhesion molecule connexin-40 (a candidate for the main body of baroreceptor); and pressurization to atmospheric pressure + 100 mmHg. culture in hypotonic liquid medium. The expression of renin under these conditions was measured by qRT-PCR. (3) Results: Phosphorylation of β1-integrin suppressed the expression of renin, while dephosphorylation conversely promoted it. β1-integrin and connexin-40 knockdown both promoted the expression of renin. Pneumatic pressurization and hypotonic medium culture both decreased the expression of renin, which was restored by the knockdown of β1-integrin. (4) Conclusions: β1-integrin plays an inhibitory role in the regulation of the expression of renin, which may be controlled by phosphorylation and dephosphorylation. It is hypothesized that β1-integrin and other adhesion factors regulate the expression of renin by altering the sensitivity of baroreceptors on the plasma membrane.

Patient-derived parathyroid organoids as a tracer and drug-screening application model

Parathyroid diseases are characterized by dysregulation of calcium homeostasis and alterations in parathyroid hormone (PTH) excretion. The development of parathyroid-targeted treatment and imaging tracers could benefit from in vitro models. Therefore, we aim to establish a patient-derived parathyroid organoid model representing human parathyroid tissue. Hyperplastic parathyroid tissue was dispersed, and parathyroid organoids (PTOs) were cultured and characterized. PTO-derived cells exhibited self-renewal over several passages, indicative of the presence of putative stem cells. Immunofluorescence and RNA sequencing confirmed that PTOs phenocopy hyperplastic parathyroid tissue. Exposure of PTOs to increasing calcium concentrations and PTH-lowering drugs resulted in significantly reduced PTH excretion. PTOs showed specific binding of the imaging tracers ¹¹C-methionine and ^99mTc-sestamibi. These data show the functionality of PTOs resembling the parathyroid. This PTO model recapitulates the originating tissue on gene and protein expression and functionality, paving the way for future physiology studies and therapeutic target and tracer discovery.

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

INTRODUCTION

Cinacalcet is a calcimimetic that modulates the functions of calcium-sensing receptor and is currently used to treat patients with primary hyperparathyroidism (PHPT). Although it was reported that cinacalcet treatment reduced the size of hyperplastic parathyroid glands in patients with secondary hyperparathyroidism, whether or not cinacalcet treatment can reduce the size of parathyroid adenomas in patients with PHPT has been unknown.

MATERIALS AND METHODS

We recruited nine (male: one, female: eight) patients with PHPT due to parathyroid adenomas who did not undergo parathyroidectomy. Cinacalcet was administered at a dose of 50 mg/day, and we evaluated the size of parathyroid adenomas (width × thickness) (mm²) using ultrasonography before and after 6 months of cinacalcet treatment.

RESULTS

The mean age of the subjects was 58.1 ± 7.2 years old, and the mean serum intact parathyroid hormone (PTH) concentration was 134.8 ± 8.7 pg/ml. All participants showed hypercalcemia and osteopenia. After 6 months, the mean size of parathyroid adenomas was significantly decreased (baseline: 73.8 ± 33.4 mm² vs. after 6 months: 52.5 ± 25.0 mm², p = 0.045). Thus, 6-month cinacalcet treatment induced a 29% size reduction in parathyroid adenomas. Furthermore, the serum intact PTH concentration before cinacalcet treatment was positively correlated with the reduction in the size of parathyroid adenomas.

CONCLUSION

The present study revealed that cinacalcet treatment reduces the size of parathyroid adenomas in patients with PHPT. The accumulation of more PHPT cases with cinacalcet therapy is required to confirm this finding.

International Union of Basic and Clinical Pharmacology. CVIII. Calcium-Sensing Receptor Nomenclature, Pharmacology, and Function

The calcium-sensing receptor (CaSR) is a class C G protein-coupled receptor that responds to multiple endogenous agonists and allosteric modulators, including divalent and trivalent cations, L-amino acids, γ-glutamyl peptides, polyamines, polycationic peptides, and protons. The CaSR plays a critical role in extracellular calcium (Ca2+ o) homeostasis, as demonstrated by the many naturally occurring mutations in the CaSR or its signaling partners that cause Ca2+ o homeostasis disorders. However, CaSR tissue expression in mammals is broad and includes tissues unrelated to Ca2+ o homeostasis, in which it, for example, regulates the secretion of digestive hormones, airway constriction, cardiovascular effects, cellular differentiation, and proliferation. Thus, although the CaSR is targeted clinically by the positive allosteric modulators (PAMs) cinacalcet, evocalcet, and etelcalcetide in hyperparathyroidism, it is also a putative therapeutic target in diabetes, asthma, cardiovascular disease, and cancer. The CaSR is somewhat unique in possessing multiple ligand binding sites, including at least five putative sites for the "orthosteric" agonist Ca2+ o, an allosteric site for endogenous L-amino acids, two further allosteric sites for small molecules and the peptide PAM, etelcalcetide, and additional sites for other cations and anions. The CaSR is promiscuous in its G protein-coupling preferences, and signals via Gq/11, Gi/o, potentially G12/13, and even Gs in some cell types. Not surprisingly, the CaSR is subject to biased agonism, in which distinct ligands preferentially stimulate a subset of the CaSR's possible signaling responses, to the exclusion of others. The CaSR thus serves as a model receptor to study natural bias and allostery. SIGNIFICANCE STATEMENT: The calcium-sensing receptor (CaSR) is a complex G protein-coupled receptor that possesses multiple orthosteric and allosteric binding sites, is subject to biased signaling via several different G proteins, and has numerous (patho)physiological roles. Understanding the complexities of CaSR structure, function, and biology will aid future drug discovery efforts seeking to target this receptor for a diversity of diseases. This review summarizes what is known to date regarding key structural, pharmacological, and physiological features of the CaSR.

Effectiveness and safety of cinacalcet for primary hyperparathyroidism: a single center experience

Primary hyperparathyroidism (PHPT) is a common endocrine disease. Although surgical treatment is curative in most cases, there are few alternative therapies for the hypercalcemia caused by PHPT. Cinacalcet is a positive allosteric modulator of the calcium sensing receptor and was conditionally approved in Japan in 2014 to treat PHPT cases. However, there have been few reports on the outcomes. In our present study, we investigated the efficacy and safety of cinacalcet in 61 PHPT patients who were treated with this agent at our hospital between January 2014 and March 2017. The corrected serum Ca and intact PTH levels were significantly reduced by this treatment, whereas the serum phosphorus levels significantly increased. There were no significant differences in the eGFR or urinary Ca to urinary creatinine ratio between baseline and the maintenance phase. In terms of bone mineral density, there were significant increases observed in the 16 cases for whom a baseline value was available, 11 of whom had been treated for osteoporosis. The most common adverse events from cinacalcet treatment were gastrointestinal symptom, such as nausea and appetite loss. Other adverse events included severe dehydration due to hypercalcemia, myalgia, hypocalcemia, and increased urinary calcium excretion. Seven patients were switched to surgical treatment, and the drug was discontinued in 9 other patients, due to adverse effects. Our present study findings demonstrate that cinacalcet is an effective therapeutic option for PHPT from the perspective of hypercalcemia improvement but that adverse gastrointestinal effects of this drug occur at a frequency of about 10%.

A case of hyperparathyroidism-associated parkinsonism successfully treated with cinacalcet hydrochloride, a calcimimetic

Background

Some metabolic disorders, including abnormal calcium metabolism, can develop and worsen parkinsonism. However, whether hyperparathyroidism can cause parkinsonism remains controversial.

Case presentation

An 83-year-old woman with a history of right thalamic hemorrhage and drug-induced parkinsonism, was admitted due to worsening of parkinsonian symptoms including mask-like face, bradykinesia, freezing of gait, and rigidity. She had been diagnosed with autoimmune hepatitis and was being treated with prednisolone. Examinations revealed hypercalcemia (14.3 mg/dL) with an increased level of intact parathyroid hormone (iPTH) (361 pg/mL). Her symptoms were resistant to some additional anti-parkinsonian drugs; however, cinacalcet hydrochloride, a calcimimetic for the treatment of secondary hyperparathyroidism, normalized levels of serum calcium and iPTH, and remarkably improved her symptoms.

Conclusions

In the present case, we speculate that hypercalcemia probably due to secondary hyperparathyroidism that had developed during steroid therapy deteriorated the parkinsonism.

Parathyroid Apoplexy Following Cinacalcet Treatment in Primary Hyperparathyroidism

Cinacalcet, a calcimimetic drug, is considered a safe and valid option for the treatment of hypercalcemia in patients with primary hyperparathyroidism who are unable to undergo parathyroidectomy. Hypocalcemia and gastrointestinal adverse reactions are the main side effects reported in patients treated with cinacalcet. We present here the case of an 80-years-old patient with primary hyperparathyroidism treated with cinacalcet for 17 months who developed a severe and symptomatic episode of hypocalcemia requiring hospitalization 1 month after reaching a daily dose of 180 mg. Follow-up laboratory and imaging exams showed remission of primary hyperparathyroidism and disappearance of the parathyroid adenoma, suggesting a possible association between cinacalcet therapy and parathyroid infarction resulting in normalization of the elevated serum parathyroid hormone levels and severe hypocalcemia. No known cases of iatrogenic parathyroid apoplexy have thus far been described. We report here the first case of parathyroid apoplexy associated with the administration of cinacalcet in a patient with primary hyperparathyroidism. Parathyroid apoplexy features heterogeneous clinical manifestations ranging from relatively asymptomatic to potentially life-threatening cases. The occurrence of this complication should be carefully considered in patients with primary hyperparathyroidism in therapy with cinacalcet.

Parathyroid Nodular Hyperplasia and Responsiveness to Drug Therapy in Renal Secondary Hyperparathyroidism: An Open Question

The goal of the pharmacological therapy in secondary hyperparathyroidism (SHPT) is to reduce serum levels of parathyroid hormone and phosphorus, to correct those of calcium and vitamin D, to arrest or reverse the parathyroid hyperplasia. However, when nodular hyperplasia or an autonomous adenoma develops, surgery may be indicated. We reviewed the literature with the aim of defining if the echographic criteria predictive of unresponsiveness of SHPT to calcitriol therapy are valid also in the cinacalcet era and if drug therapy may reverse nodular hyperplasia of parathyroid gland (PTG). The responsiveness to therapy and regression of the nodular hyperplasia of PTG remains an open question in the calcimimetic era as well as the cutoff between medical and surgical therapy. Prospective studies are needed in order to clarify if an earlier use of cinacalcet in moderate SHPT might arrest the progression of parathyroid growth and stabilize SHPT.

The Calcium-Sensing Receptor and the Parathyroid: Past, Present, Future

Parathyroid hormone (PTH) defends the extracellular fluid from hypocalcemia and has powerful and well-documented actions on the skeleton and renal tubular system. To achieve a satisfactory stable plasma calcium level, the secretion of PTH, and the resulting serum PTH level, is titrated carefully to the prevailing plasma ionized Ca²⁺ concentration via a Ca²⁺ sensing mechanism that mediates feedback inhibition of PTH secretion. Herein, I consider the properties of the parathyroid Ca²⁺ sensing mechanism, the identity of the Ca²⁺ sensor, the intracellular biochemical mechanisms that it controls, the manner of its integration with other components of the PTH secretion control mechanism, and its modulation by other nutrients. Together the well-established, recently elucidated, and yet-to-be discovered elements of the story constitute the past, present, and future of the parathyroid and its calcium-sensing receptor (CaSR).

Clinical and Practical Use of Calcimimetics in Dialysis Patients With Secondary Hyperparathyroidism

CKD and CKD-related mineral and bone disorders (CKD-MBDs) are associated with high cardiovascular and mortality risks. In randomized clinical trials (RCTs), no single drug intervention has been shown to reduce the high mortality risk in dialysis patients, but several robust secondary analyses point toward important potential beneficial effects of controlling CKD-MBD-related factors and secondary hyperparathyroidism. The advent of cinacalcet, which has a unique mode of action at the calcium-sensing receptor, represented an important step forward in controlling CKD-MBD. In addition, new RCTs have conclusively shown that cinacalcet improves achievement of target levels for all of the metabolic abnormalities associated with CKD-MBD and may also attenuate the progression of vascular and valvular calcifications in dialysis patients. However, a final conclusion on the effect of cinacalcet on hard outcomes remains elusive. Tolerance of cinacalcet is limited by frequent secondary side effects such as nausea, vomiting, hypocalcemia and oversuppression of parathyroid hormone, which may cause some management difficulties, especially for those lacking experience with the drug. Against this background, this review aims to summarize the results of studies on cinacalcet, up to and including the publication of the recent ADVANCE and EVOLVE RCTs, as well as recent post hoc analyses, and to offer practical guidance on how to improve the clinical management of the most frequent adverse events associated with cinacalcet, based on both currently available information and personal experience. In addition, attention is drawn to less common secondary effects of cinacalcet treatment and advisable precautions.

Upregulation of α3β1-Integrin in Podocytes in Early-Stage Diabetic Nephropathy

Background. Podocyte injury plays an important role in the onset and progression of diabetic nephropathy (DN). Downregulation of α3β1-integrin expression in podocytes is thought to be associated with podocyte detachment from the glomerular basement membrane, although the mechanisms remain obscure. To determine the mechanism of podocyte detachment, we analyzed the expression levels of α3β1-integrin in podocytes in early and advanced stages of DN. Methods. Surgical specimens from DN patients were examined by in situ hybridization, and the expression levels of α3- and β1-integrin subunits in glomeruli of early (n = 6) and advanced (n = 8) stages were compared with those of normal glomeruli (n = 5). Heat-sensitive mouse podocytes (HSMP) were cultured with TGF-β1 to reproduce the microenvironment of glomeruli of DN, and the expression levels of integrin subunits and the properties of migration and attachment were examined. Results. Podocytes of early-stage DN showed upregulation of α3- and β1-integrin expression while those of advanced stage showed downregulation. Real-time PCR indicated a tendency for upregulation of α3- and β1-integrin in HSMP cultured with TGF-β1. TGF-β1-stimulated HSMP also showed enhanced in vitro migration and attachment on collagen substrate. Conclusions. The results suggested that podocyte detachment during early stage of DN is mediated through upregulation of α3β1-integrin.

Two Years of Cinacalcet Hydrochloride Treatment Decreased Parathyroid Gland Volume and Serum Parathyroid Hormone Level in Hemodialysis Patients With Advanced Secondary Hyperparathyroidism

The long-term effect of cinacalcet hydrochloride treatment on parathyroid gland (PTG) volume has been scarcely investigated in patients with moderate to advanced secondary hyperparathyroidism (SHPT). The present study was a prospective observational study to determine the effect of cinacalcet treatment on PTG volume and serum biochemical parameters in 60 patients with renal SHPT, already treated with intravenous vitamin D receptor activator (VDRA). Measurement of biochemical parameters and PTG volumes were performed periodically, which were analyzed by stratification into tertiles across the baseline parathyroid hormone (PTH) level or PTG volume. We also determined the factors that can estimate the changes in PTG volume and the achievement of the target PTH range by multivariable analyses. Two years of cinacalcet treatment significantly decreased the serum levels of PTH, calcium, and phosphate, followed by the improvement of achieving the target ranges for these parameters recommended by the Japanese Society for Dialysis Therapy. Cinacalcet decreased the maximal and total PTG volume by about 30%, and also decreased the serum PTH level independent of the baseline serum PTH level and PTG volume. Ten out of 60 patients showed 30% increase in maximal PTG after 2 years. Multivariable analysis showed that patients with nodular PTG at baseline and patients with higher serum calcium and PTH levels at 1 year were likely to exceed the target range of PTH at two years. In conclusion, cinacalcet treatment with intravenous VDRA therapy decreased both PTG volume and serum intact PTH level, irrespective of the pretreatment PTG status and past treatment history.