Effects of PTH and PTH Hypersecretion on Bone: a Clinical Perspective

Revisiting the evolution of Family B1 GPCRs and ligands: Insights from mollusca

Family B1 G protein-coupled receptors (GPCRs) are one of the most well studied neuropeptide receptor families since they play a central role in many biological processes including endocrine, gastrointestinal, cardiovascular and reproduction in animals. The genes for these receptors emerged from a common ancestral gene in bilaterian genomes and evolved via gene/genome duplications and deletions in vertebrate and invertebrate genomes. Their existence and function have mostly been characterized in vertebrates and few studies exist in invertebrate species. Recently, an increased interest in molluscs, means a series of genomes have become available, and since they are less modified than insect and nematode genomes, they are ideal to explore the origin and evolution of neuropeptide gene families. This review provides an overview of Family B1 GPCRs and their peptide ligands and incorporates new data obtained from Mollusca genomes and taking a comparative approach challenges existing models on their origin and evolution.

Patellar and quadriceps tendon rupture are associated with hip fracture in hemodialysis patients with severe hyperparathyroidism

Spontaneous rupture of the patellar (PTR) and quadriceps (QTR) tendon is infrequent. Systemic diseases such as diabetes mellitus, CKD, and secondary hyperparathyroidism (SHPT) are risk factors. The present cohort study aimed to evaluate risk factors associated with tendon rupture in hemodialysis (HD) patients with SHPT, as well as outcomes including surgical complications, re-ruptures, and fracture. Baseline clinical, laboratorial data, and radiographs were analyzed. Patients were followed up from March 2012 to March 2020. One-hundred thirty-one patients (≥18 yr of age, on HD ≥ 6 mo, with SHPT) were included. Incidence rates of PTR and QTR were 2.3 and 1.7/10000 HD patients/yr, respectively. The mean age of patients with tendon rupture was 44.0 ± 11.2 yr. These patients exhibited higher serum levels of phosphorus (6.3 ± 1.5 mg/dL vs 5.6 ± 1.1 mg/dL; P = .005), PTH (2025.7 ± 667.6 pg/mL vs 1728.4 ± 684.8 pg/mL; P = .035), and C-reactive-protein (35.4 ± 32.9 mg/dL vs 17 ± 24.5 mg/dL; P = .002) compared to the group without tendon rupture. The mean follow-up was 56.7 ± 27.1 mo. No patient required a new surgical approach or experienced re-rupture. Of all patients, 31% experienced hip fracture: 50% in the group with rupture (29.5 ± 17.4 mo after the tendon rupture) vs 26% without tendon rupture (P = .015). After adjustment, the hazard ratio for hip fracture was 2.87 (95% CI, 1.27-6.49; P = .012). Patients with SHPT and high levels of phosphorus, PTH, and inflammatory markers were at greater risk for tendon rupture. Surgical complication rates were low. However, results suggest that tendon rupture of knee extensor mechanism in HD patient with SHPT should be regarded as a "red flag" for future hip fracture.

Different types of hip fragility fractures have different values of 25-hydroxyvitamin D and parathyroid hormone

BACKGROUND

Vitamin D insufficiency/deficiency is related to fragility fracture. In most previous studies, there was no assessment of vitamin D deficiency status separately for hip fracture types. The first aim is to evaluate vitamin D and parathyroid hormone (PTH) status in patients with hip fracture. The second objective is to determine whether there are differences in vitamin D and PTH between the femoral neck fracture and the femoral metaphyseal fracture group.

METHODS

62 men and 248 women with fragility hip fractures were enrolled. 25-hydroxyviamin D [25(OH)D] and intact PTH (iPTH) values were evaluated, and femoral neck bone mineral density (BMD) was measured on the uninjured side. Vertebral fractures (VFs) were assessed using radiographs of the thoracic and lumbar spine. We examined the relationships of 25(OH)D value with the number of prevalent VFs, T-score of femoral neck, and iPTH level. These analyses were also performed, neck fracture and trochanteric fracture separately.

RESULTS

Mean age was 85 years. The mean 25(OH)D was 11.2 (range, 4.0-26.1) ng/ml, whereas the mean iPTH value was 48.9 pg/ml (range, 9-429 pg/ml). The mean number of VFs was 1.5 (range, 0-11), and the mean T-score was -3.3 (range, -5.2 to -0.5). There was a weak correlation between the 25(OH)D value and the number of VFs. There was a weak but significant correlation between 25(OH)D and iPTH values. In the patients with trochanteric fractures, 25(OH)D value was significantly lower and iPTH value was significantly higher than those with neck fractures. There was a significant correlation between the 25(OH)D value and number of the VFs, 25(OH)D, and iPTH values only in trochanteric fractures.

CONCLUSIONS

Vitamin D deficiency was severe and PTH levels were higher in the trochanteric fractures. Both vitamin D deficiency and high PTH levels were suggested to have association with bone fragility.

New Insights in the Pathophysiology, Epidemiology, and Response to Treatment of Osteoporotic Vertebral Fractures

CONTEXT

Vertebral fractures (VFs) make up an important but challenging group of fractures often caused by osteoporosis. Osteoporotic fractures pose unique diagnostic challenges in generally requiring imaging for diagnosis. The objective of this narrative mini-review is to provide an overview of these recent advances in our knowledge of VF pathophysiology and epidemiology with particular focus on endocrine diseases, prevention, and treatment.

EVIDENCE ACQUISITION

We searched PubMed on May 23, 2022, for studies of VFs in humans. Results were limited to papers available as full-text publications in English, published from 2020 and onward. This yielded 3457 citations. This was supplemented by earlier publications selected to add context to the recent findings.

EVIDENCE SYNTHESIS

Studies addressed VF risk in hyperthyreosis, hyperparathyroidism, acromegaly, Cushing syndrome, primary aldosteronism, and diabetes. For pharmaceutical treatment, new studies or analyses were identified for romosozumab and for weekly teriparatide. Several studies, including studies in the immediate pipeline, were intervention studies with vertebroplasty or kyphoplasty, including combination with stem cells or pharmaceuticals.

CONCLUSIONS

Endocrinologists should be aware of the high likelihood of osteoporotic VFs in patients with endocrine diseases. Though licensed treatments are able to substantially reduce the occurrence of VFs in patients with osteoporosis, the vast majority of recent or ongoing randomized controlled trials in the VF area focus on advanced invasive therapy of the fracture itself.

Shift in Calcium From Peripheral Bone to Axial Bone After Tumor Resection in Patients With Tumor-Induced Osteomalacia

CONTEXT

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by excessive production of fibroblast growth factor 23 (FGF23) by a tumor. After successful tumor resection, patients can recover from hypophosphatemia quicky. However, data on the changes in bone mineral density (BMD) and microstructure in the short term after surgery remained unclear.

OBJECTIVE

This work aimed to investigate the postoperative changes in BMD and microstructure both in peripheral and axial bone in TIO patients.

METHODS

We evaluated BMD and microarchitecture in 22 TIO patients using high-resolution peripheral quantitative computed tomography (HR-pQCT) and dual-energy x-ray absorptiometry (DXA) before and 3 months after surgery in this retrospective study.

RESULTS

In this study, a total of 22 TIO patients who had recovered serum phosphate levels postoperatively were enrolled. After surgery, areal BMD (aBMD) increased by 21.6% in the femoral neck, by 18.9% in the total hip, and by 29.5% in the lumbar spine. Moreover, TBS increased by 14.1% (all P < .001). In contrast, trabecular or cortical volumetric BMD (vBMD), and microstructure of trabecular bone (trabecular number, separation and bone volume ratio) and cortical bone (cortical thickness and porosity) at the distal radius or tibia were further deteriorated. Correlation analyses found that changes in femoral neck and total hip aBMD were both conversely associated with changes in trabecular vBMD and bone volume ratio, while positively correlated with change in trabecular separation at the distal radius.

CONCLUSION

Although aBMD and microstructure in the axial bone were improved, vBMD and microstructure in the peripheral bone were further impaired shortly after surgery. Correlation of improvement of aBMD in the total hip and femoral neck with deterioration of vBMD and microstructure at the distal radius indicated a shift in calcium from the peripheral bone to the axial bone in the short term after tumor resection in TIO patients.

Brown tumors in nuclear medicine: a systematic review

Brown tumors (BT) are abnormal bone-repair processes and a consequence of hyperparathyroidism. The diagnosis of these lytic lesions in nuclear medicine, while a challenge, is not so rare, because functional imaging is used both in the management of cancer and hyperparathyroidism. The main objective of this review is to summarize the knowledge and the evidence concerning BT and the different imaging modalities in nuclear medicine. A systematic review was performed in Embase, PubMed and Google Scholar from 2005 to 2022. We included articles describing BT in the following imaging modalities: [¹⁸F]-fluorodeoxyglucose PET/CT, [¹⁸F]-fluorocholine or [¹¹C]-fluorocholine PET/CT, [^99mTc]-Sestamibi scintigraphy, bone scan, [¹⁸F]-sodium fluoride PET/CT, [⁶⁸Ga]-FAPI PET/CT; [⁶⁸Ga]-DOTATATE PET/CT; [¹¹C]-methionine PET/CT. For each modality, appearance, avidity for radiotracer, available quantitative parameters and imaging evolution after parathyroidectomy were collected and analyzed. Fifty-two articles were included for a total of 392 BT lesions. If the diagnosis of BT is evoked on a known lesion, performing a [¹⁸F]-fluorocholine PET/CT imaging seems the most appropriate. In [¹⁸F]-fluorodeoxyglucose, [¹⁸F]-fluorocholine, [¹⁸F]-sodium fluoride PET/CT and bone scan, BT can mimic metastatic disease. BT uptakes appear reversible after parathyroidectomy, with a more or less rapid decrease depending on the imaging modality used.

Prevalence of low bone mineral density (T-score ≤ - 2.5) in the whole spectrum of chronic kidney disease: a systematic review and meta-analysis

The prevalence of low bone mineral density (LBMD) in people with chronic kidney disease (CKD) remains unknown. We identified a high prevalence of LBMD in CKD population. Thus, public health strategies should include efforts to prevent, early detect, and manage LBMD in CKD patients, especially in patients undergoing kidney replacement therapy. Mineral and bone disorders are common among patients with CKD, which affects bone mineral density. We conducted a systematic review and meta-analysis to estimate the prevalence of low bone mineral density (LBMD) in adults with CKD. We searched MEDLINE, EMBASE, Web of Science, CINAHL, and LILACS databases from inception to February 2021. Observational studies that reported the prevalence of LBMD in adults with CKD stages 3a-5D were included. The LBMD was defined according to the World Health Organization criterion (T-score ≤  - 2.5). Random-effect model meta-analyses were used to estimate the pooled prevalence of LBMD. Meta-regressions and subgroup analyses were conducted for stages of CKD, dialysis modality, gender, bone sites and morphology, and geographical region. This study was registered in PROSPERO, number CRD42020211077. One-hundred and fifty-three studies with 78,092 patients were included. The pooled global prevalence of LBMD in CKD was 24.5% (95% CI, 21.3 - 27.8%). Subgroup analyses indicated a higher prevalence of LBMD in dialysis patients (30%, 95% CI 25 - 35%) compared with non-dialysis CKD patients (12%, 95% CI 8 - 16%), cortical bone sites (28%, 95% CI 23 - 35%) relative to trabecular sites (19%, 95% CI 14 - 24%), while similar estimates in the European and the Asiatic continents (26%, 95% CI 21 - 30% vs 25%, 95% CI 21 - 29). The prevalence of LBMD in CKD patients is high, particularly in those undergoing dialysis and in cortical bone sites. Therefore, efforts to early diagnosis and management strategies should be implemented in clinical routine for an epidemiological control of LBMD in CKD patients.

DXA-based bone strain index in normocalcemic primary hyperparathyroidism

The trabecular and cortical bone assessed by bone strain index seems not to be significantly affected in NHPT.

INTRODUCTION

The natural history and bone involvement of normocalcemic hyperparathyroidism (NHPT) are not fully clarified yet. The bone strain index (BSI) is a deformation index based on the finite element method and can be applied to DXA scans. In this study, we aim to assess BSI in subjects with NHPT.

METHOD

A case-control study included 170 subjects: 40 subjects with NHPT, 50 subjects with primary hypercalcemic hyperparathyroidism (PHPT), and 80 controls (age- and sex-matched with the NPTH group).

RESULTS

Lumbar spine (LS) bone mineral density (BMD), femoral neck (FN) BMD, total hip (TH) BMD, and TBS were similar between NHPT and both PHPT and controls. FN-BSI was lower in NHPT compared to PHPT (1.52 ± 0.31 vs 1.72 ± 0.42 p = 0.031) while there were no differences between NHPT and controls. TH-BSI was lower in NHPT compared to PHPT (1.36 ± 0.23 vs 1.52 ± 0.34, p = 0.030), while there were no differences between NHPT and controls. LS-BSI was not different between NHPT and both PHPT and controls.

CONCLUSION

The trabecular and cortical bones assessed by BSI seem not to be significantly impaired in NHPT. Further prospective studies are needed to confirm these findings and to give an insight into the natural history of NHPT to improve knowledge and management of this condition.

The Dietary and Non-Dietary Management of Osteoporosis in Adult-Onset Celiac Disease: Current Status and Practical Guidance

Impaired bone mineral density (BMD) is a frequent complication of adult-onset celiac disease (CeD). This is usually due to malabsorption of nutrients, changes in bone metabolism in association with inflammation, and to a lesser extent, decreased overall physical health and mobility. This review aims to highlight the current status concerning surveillance, prevention, and treatment strategies for bone disease in CeD. A practical guidance on these matters is suggested. The available published research on the prevention and treatment of decreased BMD in relation to CeD is scarce. In general, publications were based on expert opinions or extrapolation from studies on postmenopausal women or inflammatory bowel disease. Optimal dietary treatment and an adequate supply of calcium and vitamin D are the cornerstones for the reduction in fracture risk in patients with CeD. In adults with low BMD or fragility fractures, CeD needs to be considered and specifically approached. When osteoporosis is documented, start treatment with an antiresorptive agent; these agents are proven to result in a long-term reduction in fracture risk in high-risk individuals. However, there are some important differences between the management of male and female patients, particularly premenopausal women, that need to be addressed. In patients with persisting diarrhea and malabsorption, parenteral medications may be preferable. Future research specifically focusing on celiac disease and the associated disorders in bone mineralization is mandatory to provide evidence-based recommendations in this field.

M. Assessment of trabecular and cortical parameters using high-resolution peripheral quantitative computed tomography, histomorphometry and microCT of iliac crest bone core in hemodialysis patients

Patients with end-stage renal disease develop changes in bone quality and quantity, which can be assessed using different methods. This study aimed to compare and to correlate bone parameters obtained in vivo using high-resolution peripheral quantitative computed tomography (HR-pQCT) with those obtained by bone biopsy using histomorphometry and microcomputed tomography (microCT) analysis of the iliac crest core, and to evaluate if HR-pQCT is helpful in aiding with categorization of those with high turnover. Twenty hemodialysis patients, 13 females (7 postmenopausal), underwent bone biopsy from 2018 to 2020. The mean age was 48.5 ± 10.6 years, and the mean hemodialysis vintage was 15 years. Histomorphometry identified mineralization defects, low turnover, and high turnover in 65%, 45%, and 35% of the patients, respectively. The highest values of trabecular bone volume (BV/TV) were obtained by histomorphometry, while the highest values of cortical thickness (Ct.Th) were obtained by HR-pQCT at the distal tibia. Moderate correlations were found between BV/TV values obtained by microCT of the bone core and HR-pQCT at the distal radius (r = 0.531, p = 0.016) and at the distal tibia (r = 0.536, p = 0.015). BV/TV values obtained from the bone core by histomorphometry and microCT were also significantly correlated (r = 0.475, p = 0.04). Regarding Ct.Th, there was a strong correlation between the radius and tibia HR-pQCT (r = 0.800, p < 0.001), between bone core microCT and the distal radius HR-pQCT (r = 0.610, p < 0.01), as between histomorphometry and microCT (r = 0.899, p < 0.01). In groups classified by bone turnover, patients with high turnover presented lower BV/TV, Tb.N, Tb.Th, and Ct.Th than those with low turnover in peripheral sites using HR-pQCT. By this method, it was possible to identify low turnover from tibia BV/TV > 12,4% plus Tb.Sp ≤ 0.667 mm (AUC 0.810, 95% CI 0.575 to 0.948) and high turnover from total bone mineral density (BMD) ≤ 154.2 mg HA/cm³ (AUC 0.860, 95% CI 0.633 to 0.982, p < 0.001) and cortical BMD ≤ 691.6 mg HA/cm³ (AUC 0.840, 95% CI 0.609 to 0.963, p < 0.001). In conclusion, HR-pQCT had significant correlation with iliac crest bone in BV/TV and Ct.Th, which are known to provide bone strength. This method is quick and non-invasive and may be helpful in categorizing those with high versus low turnover in hemodialysis patients.

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Bone structure in hemodialysis patients can be assessed using different methods.

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There was correlation of BV/TV and Ct.Th between histomorphometry and bone core microCT.

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BV/TV and Ct.Th values obtained by radius HR-pQCT and bone core microCT were correlated.

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High turnover patients had lower BV/TV, Tb.N, Tb.Th, and Ct.Th by HR-pQCT.

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HR-pQCT was able to discriminate low and high turnover in hemodialysis patients.

Construction and validation of a predictive model for hypocalcemia after parathyroidectomy in patients with secondary hyperparathyroidism

OBJECTIVE

We aimed to construct and validate a predictive model for the risk of hypocalcemia following parathyroidectomy (PTX) for the treatment of secondary(renal) hyperparathyroidism (SHPT).

METHODS

Information regarding patients with SHPT who underwent PTX between January 2019 and April 2022 was collected retrospectively. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for hypocalcemia following PTX and to construct predictive models. The areas under the receiver operating characteristic curve (AUC), the calibration curve, and the clinical decision curve (decision curve analysis, DCA) were used to assess the discrimination, calibration, and level of clinical benefit obtained using the predictive models.

RESULTS

We studied 238 patients who were randomly allocated in a 7:3 ratio to a training group (n=166) and a test group (n=72). Univariate and multivariate logistic regression analyses were performed, in which three variables (the circulating parathyroid hormone (PTH) and Ca concentrations, and alkaline phosphatase (ALP) activity) were interrogated for possible roles as independent risk factors for hypocalcemia in patients with SHPT who undergo PTX, and used to construct predictive models. The AUCs for the constructed models were high for both the training (0.903) and test (0.948) groups. The calibration curve showed good agreement between the incidence of postoperative hypocalcemia estimated using the predictive model and the actual incidence. The DCA curve indicated that the predictive model performed well.

CONCLUSION

A predictive model constructed using a combination of preoperative PTH, Ca, and ALP may represent a useful means of identifying patients with SHPT at high risk of developing hypocalcemia following PTX in clinical practice.

A practical approach to normocalcemic primary hyperparathyroidism

Normocalcemic primary hyperparathyroidism is an entity on which several issues about its clinical management remains unclear. This is reflected in the main current guidelines, where there are no evidence-based specific recommendations. Through an exhaustive review of current literature, a clinical management algorithm for these patients is proposed. We consider the diagnosis criteria, the differential diagnosis, the clinical manifestations, and the treatment indications. When indicated, we also review the preoperative locations techniques and the surgical approach. Finally, when surgical treatment is not indicated, the patient is not a candidate to surgery or refuse surgical management, we review the medical treatment options and the follow-up schemes.

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.

DXA-Based Bone Strain Index: A New Tool to Evaluate Bone Quality in Primary Hyperparathyroidism

CONTEXT

Primary hyperparathyroidism (PHPT) is associated with impaired bone quality and increased fracture risk. Reliable tools for the evaluation of bone quality parameters are not yet clinically available. Bone Strain Index (BSI) is a new metric for bone strength based on Finite Element Analysis from lumbar spine and femoral neck dual-energy x-ray absorptiometry (DXA) images.

OBJECTIVE

To assess the lumbar spine (LS), femoral neck (FN), and total hip (TH) BSI in PHPT patients compared with controls and to investigate the association of BSI with vertebral fractures (VFs) in PHPT.

METHODS

This case-control study enrolled 50 PHPT patients and 100 age- and sex-matched control subjects from an outpatient clinic. The main outcome measures were LS-BSI, FN-BSI, and TH-BSI.

RESULTS

FN bone mineral density (BMD) and one-third distal radius BMD were lower in the PHPT group than in controls (FN 0.633 ± 0.112 vs 0.666 ± 0.081, P = 0.042; radius 0.566 ± 0.07 vs 0.625 ± 0.06, P < 0.001). PHPT group has significant lower TBS score compared with controls (1.24 ± 0.09 vs 1.30 ± 0.10, P < 0.001). BSI was significantly higher at LS (2.28 ± 0.59 vs 2.02 ± 0.43, P = 0.009), FN (1.72 ± 0.41 vs 1.49 ± 0.35, P = 0.001), and TH (1.51 ± 0.33 vs 1.36 ± 0.25, P = 0.002) in PHPT. LS-BSI showed moderate accuracy for discriminating VFs (AUC 0.667; 95% CI, 0.513-0.820). LS-BSI ≥ 2.2 and was a statistically significant independent predictor of VFs, with an adjusted odds ratio ranging from 5.7 to 15.1.

CONCLUSION

BSI, a DXA-derived bone quality index, is impaired in PHPT and may help to identify PHPT subjects at high risk of fractures.

Therapeutic potential of iron chelators on osteoporosis and their cellular mechanisms

Iron is an essential trace element in the metabolism of almost all living organisms. Iron overload can disrupt bone homeostasis by significant inhibition of osteogenic differentiation and stimulation of osteoclastogenesis, consequently leading to osteoporosis. Iron accumulation is also involved in the osteoporosis induced by multiple factors, such as estrogen deficiency, ionizing radiation, and mechanical unloading. Iron chelators are first developed for treating iron overloaded disorders. However, growing evidence suggests that iron chelators can be potentially used for the treatment of bone loss. In this review, we focus on the therapeutic effects of iron chelators on bone loss. Iron chelators have therapeutic effects not only on iron overload induced osteoporosis, but also on osteoporosis induced by estrogen deficiency, ionizing radiation, and mechanical unloading, and in Alzheimer's disease-associated osteoporotic deficits. Iron chelators differently affect the cellular behaviors of bone cells. For osteoblast lineage cells (bone mesenchymal stem cells and osteoblasts), iron chelation stimulates osteogenic differentiation. Conversely, iron chelation significantly inhibits osteoclast differentiation. These different responses may be associated with the different needs of iron during differentiation. Fibroblast growth factor 23, angiogenesis, and antioxidant capability are also involved in the osteoprotective effects of iron chelators.

Bone Turnover Markers in Response to Ultrasound-Guided Microwave Ablation for Primary Hyperparathyroidism

OBJECTIVE

To assess the efficacy and safety of ultrasound-guided microwave ablation (MWA) in the treatment of primary hyperparathyroidism (PHPT), and to investigate whether MWA can improve the bone turnover and renal function.

METHODS

A total of 20 consecutive PHPT patients with 21 parathyroid lesions treated with MWA in our center from May 2019 to March 2021 were recruited in this study. Serum parathyroid hormone (PTH), calcium and phosphorus levels before MWA and at 20 minutes, 4 hours, 1 day, 3 months, 6 months and 12 months after MWA were measured. Bone turnover biomarkers, renal function and lesion volume with volume reduction rate (VRR) before MWA and at the last follow-up were compared. Any complication related with MWA was evaluated. The technical and clinical success rates of MWA in the treatment of PHPT were calculated. Clinical success was defined as normal serum PTH and calcium without PHPT-associated manifestations at more than 6 months after ablation. Technical success was defined as complete ablation indicated by immediate postoperative contrast-enhanced ultrasound.

RESULTS

The serum PTH, calcium and phosphorus levels at their respective follow-up time points dropped significantly after MWA (P <0.05). The volume of parathyroid lesions at the final examination was significantly reduced, compared with pre-ablation volume (P <0.001), with a median VRR reaching 89%. The technical and clinical success rates were 100% and 63.6%, respectively. Substantial changes of bone turnover biomarkers were observed before and after MWA (P <0.05), but the differences in renal function were not statistically significant. No major complications were reported in all cases. Pre-MWA serum PTH, lesion volume, maximum diameter of lesion and ablation time were significantly different between patients with successful and failed MWA.

CONCLUSIONS

PHPT can be effectively and safely treated by ultrasound-guided MWA, as proven by drop in serum PTH and reduction in the volume of parathyroid adenomas. Besides, MWA can impede bone remodeling to suppress hyperparathyroidism in the condition of PHPT.

Relationship between Serum 25(OH)D and Depression: Causal Evidence from a Bi-Directional Mendelian Randomization Study

The relationship between depression and vitamin D deficiency is complex, with evidence mostly from studies affected by confounding and reverse causality. We examined the causality and direction of the relationship between 25-hydroxyvitamin D (25(OH)D) and depression in bi-directional Mendelian randomization (MR) analyses using information from up to 307,618 white British participants from the UK Biobank and summary results from the SUNLIGHT (n = 79,366) and Psychiatric Genomics consortia (PGC 113,154 cases and 218,523 controls). In observational analysis, the odds of depression decreased with higher 25(OH)D concentrations (adjusted odds ratio (OR) per 50% increase 0.95, 95%CI 0.94–0.96). In MR inverse variance weighted (IVW) using the UK Biobank, there was no association between genetically determined serum 25(OH)D and depression (OR per 50% higher 0.97, 95%CI 0.90–1.05) with consistent null association across all MR approaches and in data from PGC consortium. In contrast, genetic liability to depression was associated with lower 25(OH)D concentrations (MR IVW −3.26%, −4.94%–−1.55%), with the estimates remaining generally consistent after meta-analysing with the consortia. In conclusion, we found genetic evidence for a causal effect of depression on lower 25(OH)D concentrations, however we could not confirm a beneficial effect of nutritional vitamin D status on depression risk.

Therapy-Resistant Hypercalcemia in a Patient with Inactivating CYP24A1 Mutation and Recurrent Nephrolithiasis: Beware of Concomitant Hyperparathyroidism

We describe a case harboring a homozygous CYP24A1 mutation with mild loss of function, first presenting with recurrent nephrolithiasis from the age of 22 onward, initially associated with hypercalcemia and low PTH concentrations. Over the years, hyperparathyroidism developed, resulting in more severe hypercalcemia. Also, kidney function deteriorated, most probably as a consequence of biopsy-proven nephrocalcinosis. Conventional treatment options for CYP24A1 mutation were not effective and/or tolerated (avoidance of sun exposure, diet, pamidronate, itraconazole). A total parathyroidectomy was performed resulting in a normocalcemic hypoparathyroidism without need for treatment with vitamin D analogs, a positive bone mineral balance and an improved kidney function.

Parathyroid adenoma combined with a rib tumor as the primary disease: A case report

BACKGROUND

Parathyroid adenoma is a benign parathyroid tumor, with serum parathyroid hormone and calcium ion concentrations as the typical basis for diagnosis. Its clinical manifestations are complex and changeable; thus it is easily missed or misdiagnosed. Approximately 85% of patients with parathyroid adenoma develop primary hyperparathyroidism, and abnormalities in bones, kidneys and other organs can occur. Brown tumors are rare.

CASE SUMMARY

We report a rare case of fibrocystic osteitis associated with a parathyroid adenoma, which was discovered by chance due to a rib tumor. Abnormally elevated serum parathyroid hormone and calcium ion were found before surgery. We suspected primary hyperparathyroidism, and color Doppler ultrasound suggested the presence of a thyroid mass. With informed consent by the patient and her family, we first removed the rib tumor, and one week later, resection of the parathyroid adenoma and thyroid mass was performed on both sides, and the patient recovered well after surgery.

CONCLUSION

In the case of parathyroid adenoma combined with brown tumor, the bone cyst will gradually decrease in size with time without treatment. If not, surgery should be performed as soon as possible.