Hypoparathyroidism and mortality after total thyroidectomy: A nationwide matched cohort study.

OBJECTIVE: Total thyroidectomy (TT) carries a risk of hypoparathyroidism (hypoPT). Recently, hypoPT has been associated with higher overall mortality rates. We aimed to evaluate the frequency of hypoPT and mortality in patients undergoing TT in Denmark covering 20 years. DESIGN: Retrospective Cohort study. PATIENTS AND MEASUREMENTS: Using population-based registries, we identified all Danish individuals who had undergone TT between January 1998 and December 2017. We included a comparison cohort by randomly selecting 10 citizens for each patient, matched on sex and birth year. HypoPT was defined as treatment with active vitamin D after 12 months postoperatively. We used cumulative incidence to calculate risks and Cox regression to compare the rate of mortality between patients and the comparison cohort. We evaluated patients in different comorbidity groups using the Charlson Comorbidity Index and by different indications for surgery. RESULTS: 7912 patients underwent TT in the period. The prevalence of hypoPT in the study period was 16.6%, 12 months postoperatively. After adjusting for potential confounders the risk of death due to any causes (hazard ratio; 95% confidence intervals) following TT was significantly increased (1.34; 1.15-1.56) for patients who developed hypoPT. However, subgroup analysis revealed mortality was only increased in malignancy cases (2.48; 1.99-3.10) whereas mortality was not increased when surgery was due to benign indications such as goitre (0.88; 0.68-1.15) or thyrotoxicosis (0.86; 0.57-1.28). CONCLUSIONS: The use of active vitamin D for hypoPT was prevalent one year after TT. Patients with hypoPT did not have an increased risk of mortality following TT unless the indication was due to malignancy.

Autofluorescence-guided hemithyroidectomy in a low-volume thyroid institution with no experience in parathyroid surgery: randomized clinical trial.

BACKGROUND: Recent studies suggest that low-volume surgeons with no experience in parathyroid surgery are at increased risk of causing parathyroid gland damage during thyroid surgery. The aim of this RCT was to evaluate the impact of using autofluorescence in hemithyroidectomy on parathyroid gland identification and preservation in a low-volume institution with no experience in parathyroid surgery. METHODS: Patients referred for hemithyroidectomy were randomized 1 : 1 to either autofluorescence-guided hemithyroidectomy (the near-infrared autofluorescence group) or conventional hemithyroidectomy (the control group). The primary outcome was parathyroid gland identification rate. Secondary outcomes were the rate of parathyroid gland autotransplantation and the rate of inadvertent parathyroid gland excision. RESULTS: A total of 170 patients were randomized to either autofluorescence-guided hemithyroidectomy (84 patients) or conventional hemithyroidectomy (86 patients). In the near-infrared autofluorescence group, 81.0% of parathyroid glands were identified, compared with 57.0% in the control group (P < 0.001). Autofluorescence enabled parathyroid gland visualization before the naked eye in 46.3% of cases. Surgeons had lower confidence in the parathyroid gland identification process in the control group than in the near-infrared autofluorescence group (59.1% versus 87.5% respectively; P < 0.001). In the near-infrared autofluorescence group, the parathyroid gland autotransplantation rate was initially high, but declined over time. There was no difference in the rate of inadvertent parathyroid gland excision. CONCLUSION: Autofluorescence guidance significantly improved the parathyroid gland identification rate in hemithyroidectomy in a low-volume institution with no experience in parathyroid surgery and provided an increase in surgical confidence. The pattern of parathyroid gland autotransplantation in autofluorescence-guided surgery indicates the presence of a learning curve. REGISTRATION NUMBER: NCT05044351 (http://www.clinicaltrials.gov).

Damage to the parathyroid glands is common during thyroid surgery. The main reason for that is that they can be difficult to see during surgery. The aim of this study was to see if the use of a new near-infrared camera during thyroid surgery could make it easier to see the parathyroid glands. Patients, where removal of part of their thyroid gland was planned, were randomly assigned to one of two groups. In the first group, the near-infrared camera was used, whereas it was not used in the other group. When the near-infrared camera was used, more parathyroid glands were found and the surgeons felt more secure in their handling of parathyroid glands.

The effect of parathyroidectomy compared to non-surgical surveillance on kidney function in primary hyperparathyroidism: a nationwide historic cohort study.

BACKGROUND: Patients with primary hyperparathyroidism (pHPT) and impaired kidney function (estimated glomerular filtration rate (eGFR) < 60 mL/min) are offered parathyroidectomy (PTX) to protect them from further complications. Surprisingly, two recent uncontrolled cohort studies have suggested a further decrease in kidney function following PTX. We aimed to examine the effects of PTX compared to non-surgical surveillance on kidney function in pHPT patients. METHODS: Historic cohort study. From the Danish National Patient Registry (NPR) and major medical biochemistry laboratories in Denmark, we identified 3585 patients with biochemically confirmed pHPT among whom n = 1977 (55%) were treated with PTX (PTX-group) whereas n = 1608 (45%) were followed without surgery (non-PTX group). Baseline was defined as time of diagnosis and kidney function was re-assessed 9-15 months after PTX (PTX group) or 9-15 months after diagnosis (non-PTX group). RESULTS: At follow-up, eGFR had decreased significantly in the PTX- compared to the non-PTX-group (median - 4% vs. - 1%, p < 0.01). Stratification by baseline eGFR showed that the decrease was significant for those with a baseline eGFR value of 80-89 and > 90 mL/min, but not for those with lower eGFR values. Findings did not differ between patients with mild compared to moderate/severe hypercalcemia. However, after mutual adjustments, we identified baseline levels of calcium, PTH, and eGFR as well as age and treatment (PTX vs. no-PTX) as independent predictors for changes in kidney function. CONCLUSION: Compared to non-surgical surveillance, PTX is associated with a small but significant decrease in kidney function in pHPT patients with an initial normal kidney function.

Health-related quality of life improves 1 year after parathyroidectomy in primary hyperparathyroidism: A prospective cohort study.

OBJECTIVE: Impaired quality of life (QoL) in primary hyperparathyroidism (PHPT) is commonly present. Patients may complain about nonspecific neurocognitive symptoms which can be difficult to quantify. Two different disease-specific questionnaires have been developed, that is, the parathyroid assessment of symptoms score (PAS) and the primary hyperparathyroidism quality of life (PHPQoL). Using these two questionnaires, we assessed relationship between QoL and biochemical indices in PHPT and effects of parathyroidectomy (PTX). DESIGN: A prospective cohort study. METHODS: Patients with PHPT diagnosed from 2015 to 2017 were asked to answer the questionnaires before and 12 months after PTX. Biochemistry was obtained on both occasions. RESULTS: A total of 104 PHPT patients answered PAS and PHPQoL questionnaires at baseline, with a median age of 64 years (73% females). PHPQoL score correlated inversely with ionized calcium and PTH at baseline (P Ë‚ 0.04). Total PAS and PHPQoL score did not differ between those with and without osteoporosis, renal calcifications and impaired renal function. Based on levels of ionized calcium, PHPQoL differed significantly between patients with mild- and moderate-severe hypercalcemia (P = 0.01). Fifty-three patients answered PAS and PHPQoL 12 months after PTX showing an improved QoL at follow-up (Pall  Ë‚ 0.02). Stratifying patients into groups based on levels of ionized calcium showed a significantly improved PHPQoL score in patients with mild (˂1.45 mmol/L) as well as moderate-severe hypercalcemia (≥1.45 mmol/L) at follow-up (Pall  Ë‚ 0.03). CONCLUSION: Quality of life improved 12 months after PTX in PHPT patients. Impaired QoL seems to be associated with the degree of hypercalcemia rather than organ manifestations attributable to PHPT.

Bone Microstructure in Response to Vitamin D3 Supplementation: A Randomized Placebo-Controlled Trial.

Vitamin D supplementation is often used in the prevention and treatment of osteoporosis, but the role of vitamin D has lately been questioned. We aimed to investigate the effect of 3 months of daily vitamin D3 supplementation (70 µg [2800 IU] vs. placebo) initiated in winter months on bone health. This study is a double-blinded placebo-controlled randomized trial. Bone health was assessed by bone turnover markers, DXA, HRpQCT, and QCT scans. The participants were 81 healthy postmenopausal women with low 25(OH)D (< 50 nmol/l) and high PTH levels (> 6.9 pmol/l) at screening. Vitamin D3 supplementation significantly increased levels of 25(OH)D and 1,25(OH)2D by 59 nmol/l and 19 pmol/l, respectively, whereas PTH was reduced by 0.7 pmol/l (all p < 0.0001). Compared with placebo, vitamin D3 did not affect bone turnover markers, aBMD by DXA or trabecular bone score. Vitamin D3 increased trabecular vBMD (QCT scans) in the trochanter region (0.4 vs. - 0.7 g/cm3) and the femoral neck (2.1 vs. - 1.8 g/cm3) pall < 0.05. HRpQCT scans of the distal tibia showed reduced trabecular number (- 0.03 vs. 0.05 mm-1) and increased trabecular thickness (0.001 vs. - 0.005 mm), as well as an improved estimated bone strength as assessed by failure load (0.1 vs. - 0.1 kN), and stiffness (2.3 vs. - 3.1 kN/mm pall ≤ 0.01). Changes in 25(OH)D correlated significantly with changes in trabecular thickness, stiffness, and failure load. Three months of vitamin D3 supplementation improved bone strength and trabecular thickness in tibia, vBMD in the trochanter and femoral neck, but did not affect aBMD.

Coordination of Fusion and Trafficking of Pre-osteoclasts at the Marrow-Bone Interface.

Fusion is the final osteoclast differentiation step leading to bone resorption. In healthy trabecular bone, osteoclast fusion is restricted to bone surfaces undergoing resorption, and necessarily requires site-specific recruitment of mononucleated pre-osteoclasts originating from the bone marrow. However, the spatiotemporal mechanism coordinating recruitment and fusion is poorly investigated. Herein we identify a collagen/vascular network as a likely structure supporting this mechanism. We therefore used multiplex immunohistochemistry and electron microscopy on human iliac crest bone samples, in combination with functional assays performed in vitro with osteoclasts generated from healthy blood donors. First, we found that putative pre-osteoclasts are in close vicinity of a network of collagen fibers associated with vessels and bone remodeling compartment canopies. Based on 3D-reconstructions of serial sections, we propose that this network may serve as roads leading pre-osteoclasts to resorption sites, as reported for cell migration in other tissues. Importantly, almost all these bone marrow pre-osteoclasts, but only some osteoclasts, express the collagen receptor OSCAR, which is reported to induce fusion competence. Furthermore, differentiating osteoclasts cultured on collagen compared to mineral show higher fusion rates, higher expression of fusogenic cytokines, and a CD47 plasma membrane distribution pattern reported to be typical of a pre-fusion state-thus collectively supporting collagen-induced fusion competence. Finally, these in vitro assays show that collagen induces high cell mobility. The present data lead to a model where collagen fibers/vasculature support the coordination between traffic and fusion of pre-osteoclasts, by serving as a physical road and inducing fusion competence as well as cell mobility.

Effects of treatment with an angiotensin 2 receptor blocker and/or vitamin D3 on parathyroid hormone and aldosterone: A randomized, placebo-controlled trial.

OBJECTIVE: Emerging evidence supports a positive, bidirectional and clinical relevant interaction between parathyroid hormone (PTH) and the renin-angiotensin-aldosterone-system (RAAS). A beneficial effect of the widely used RAAS inhibitors might include a PTH-lowering effect, as high PTH levels may be harmful to cardiovascular health. We aimed to investigate whether PTH levels are lowered by short-term treatment with an angiotensin 2 receptor blocker (valsartan) independently of coadministration of vitamin D3. Secondary end-points included effects on blood pressure, cardiac conduction and concentrations of renin and aldosterone. DESIGN AND METHODS: In a double-blind placebo-controlled trial, we included 81 otherwise healthy postmenopausal women with high PTH levels (>6.9 pmol/L) and vitamin D insufficiency (25(OH)D < 50 nmol/L). Participants received 2 weeks of treatment with valsartan 80 mg/d, vitamin D3 70 µg/d, valsartan plus vitamin D3 or double placebo. RESULTS: Valsartan treatment did not affect plasma PTH, although treatment reduced diastolic blood pressure (P = .01) and the aldosterone/renin ratio (P < .001). We found no associations between calciotropic hormones and RAAS markers. Vitamin D3 supplementation reduced PTH by 3.4% (25th, 75th -9.0 to 8.7) compared to a 7.1% increase (25th, 75th -2.4 to 30.9) in the placebo group (P = .01), but did not affect blood pressure, cardiac conduction or concentrations of renin and aldosterone. CONCLUSIONS: Independently of vitamin D3, short-term valsartan treatment did not reduce PTH. Vitamin D3 reduced PTH but did not affect blood pressure, cardiac conduction or the RAAS. The study does not support a direct association between PTH and aldosterone or a blood pressure-lowering effect of vitamin D3.

Effects of Vitamin D3 Supplementation on Muscle Strength, Mass, and Physical Performance in Women with Vitamin D Insufficiency: A Randomized Placebo-Controlled Trial.

Vitamin D insufficiency and hyperparathyroidism have been associated with reduced muscle strength, physical performance, postural stability, well-being, and quality of life. In a double-blinded, randomized placebo-controlled trial, we aimed to investigate effects of vitamin D3 supplementation on above-mentioned outcomes in healthy community-dwelling postmenopausal women with plasma levels of 25-hydroxyvitamin D (25(OH)D) below < 50 nmol/l and high parathyroid hormone (PTH) levels. Participants (N = 81) were 1:1 treated with vitamin D3, 70 µg (2800 IU)/day or identical placebo for three months during wintertime (56°N). Vitamin D3 supplementation increased levels of 25(OH)D and 1,25(OH)2D by 230% (95% CI 189 to 272)%, p < 0.001 and 58% (190 to 271%), p < 0.001, respectively, and reduced PTH by 17% (- 23 to - 11%), p < 0.001. Compared with placebo, vitamin D3 significantly reduced maximal handgrip strength by 9% (- 15 to - 3%; p < 0.01) and knee flexion strength by 13% (- 24 to - 2%; p = 0.02) and increased the time spent on performing the Timed Up and Go test by 4.4%; (0.1-8.6%; p < 0.05). Levels of physical activity, total lean body mass, appendicular lean mass index, postural stability, well-being, and quality of life did not change in response to treatment. Compared with placebo, a daily supplement with a relatively high dose of vitamin D3 had no beneficial effects on any outcomes. In some measures of muscle strength and physical performance, we even saw a small unfavorable effect. Our data call for caution on use of relatively high daily doses of vitamin D3 in the treatment of vitamin D insufficiency.

Metformin targets brown adipose tissue in vivo and reduces oxygen consumption in vitro.

AIMS: To test the hypothesis that brown adipose tissue (BAT) is a metformin target tissue by investigating in vivo uptake of [11 C]-metformin tracer in mice and studying in vitro effects of metformin on cultured human brown adipocytes. MATERIALS AND METHODS: Tissue-specific uptake of metformin was assessed in mice by PET/CT imaging after injection of [11 C]-metformin. Human brown adipose tissue was obtained from elective neck surgery and metformin transporter expression levels in human and murine BAT were determined by qPCR. Oxygen consumption in metformin-treated human brown adipocyte cell models was assessed by Seahorse XF technology. RESULTS: Injected [11 C]-metformin showed avid uptake in the murine interscapular BAT depot. Metformin exposure in BAT was similar to hepatic exposure. Non-specific inhibition of the organic cation transporter (OCT) protein by cimetidine administration eliminated BAT exposure to metformin, demonstrating OCT-mediated uptake. Gene expression profiles of OCTs in BAT revealed ample OCT3 expression in both human and mouse BAT. Incubation of a human brown adipocyte cell models with metformin reduced cellular oxygen consumption in a dose-dependent manner. CONCLUSION: These results support BAT as a putative metformin target.

Early reversal cells in adult human bone remodeling: osteoblastic nature, catabolic functions and interactions with osteoclasts.

The mechanism coupling bone resorption and formation is a burning question that remains incompletely answered through the current investigations on osteoclasts and osteoblasts. An attractive hypothesis is that the reversal cells are likely mediators of this coupling. Their nature is a big matter of debate. The present study performed on human cancellous bone is the first one combining in situ hybridization and immunohistochemistry to demonstrate their osteoblastic nature. It shows that the Runx2 and CD56 immunoreactive reversal cells appear to take up TRAcP released by neighboring osteoclasts. Earlier preclinical studies indicate that reversal cells degrade the organic matrix left behind by the osteoclasts and that this degradation is crucial for the initiation of the subsequent bone formation. To our knowledge, this study is the first addressing these catabolic activities in adult human bone through electron microscopy and analysis of molecular markers. Periosteoclastic reversal cells show direct contacts with the osteoclasts and with the demineralized resorption debris. These early reversal cells show (1) ¾-collagen fragments typically generated by extracellular collagenases of the MMP family, (2) MMP-13 (collagenase-3) and (3) the endocytic collagen receptor uPARAP/Endo180. The prevalence of these markers was lower in the later reversal cells, which are located near the osteoid surfaces and morphologically resemble mature bone-forming osteoblasts. In conclusion, this study demonstrates that reversal cells colonizing bone surfaces right after resorption are osteoblast-lineage cells, and extends to adult human bone remodeling their role in rendering eroded surfaces osteogenic.

Osteoblast recruitment routes in human cancellous bone remodeling.

It is commonly proposed that bone forming osteoblasts recruited during bone remodeling originate from bone marrow perivascular cells, bone remodeling compartment canopy cells, or bone lining cells. However, an assessment of osteoblast recruitment during adult human cancellous bone remodeling is lacking. We addressed this question by quantifying cell densities, cell proliferation, osteoblast differentiation markers, and capillaries in human iliac crest biopsy specimens. We found that recruitment occurs on both reversal and bone-forming surfaces, as shown by the cell density and osterix levels on these respective surfaces, and that bone formation occurs only above a given cell density. Canopies appeared an important source of osteoprogenitors, because (i) canopy cells proved to be more proliferative and less differentiated than bone surface cells, as shown by the inverse levels of Ki-67 and procollagen-3 N-terminal peptide versus osterix, and (ii) canopy cell densities, found to decline with age, and canopy-capillary contacts above eroded surfaces correlated positively with osteoblast density on bone-forming surfaces. Furthermore, we showed that bone remodeling compartment canopies arise from a mesenchymal envelope surrounding the red bone marrow, which is lifted and hypertrophied on initiation of bone resorption. This study, together with earlier reports, led to a model in which canopies and nearby capillaries are critical for reaching the osteoblast density required for bone formation.

Correlation between absence of bone remodeling compartment canopies, reversal phase arrest, and deficient bone formation in post-menopausal osteoporosis.

Bone remodeling compartments (BRCs) were recently recognized to be present in patients with primary hyperparathyroidism and critical for bone reconstruction in multiple myeloma and endogenous Cushing's syndrome. The BRCs are outlined by a cellular canopy separating the bone remodeling events on the bone surface from the marrow cavity. The present study on human iliac crest biopsy specimens reveals that BRC canopies appear frequently absent above both eroded and formative surfaces in post-menopausal osteoporosis patients, and that this absence was associated with bone loss in these patients. The absence of BRC canopies above the eroded surfaces was furthermore associated with the accumulation of arrested reversal surfaces and a reduced extent of formative surfaces, which both reflect an increased incidence of aborted remodeling cycles. Moreover, the absence of BRC canopies above formative surfaces was associated with a shift in the osteoblast morphological characteristics, from cuboidal to flattened. Collectively, this study shows that the BRCs are unique anatomical structures implicated in bone remodeling in a widespread disease, such as post-menopausal osteoporosis. Furthermore, it particularly highlights the role of the BRC canopies to make the reversal phase progressing toward initiation of matrix deposition, thereby preventing bone loss.

Sternotomy for substernal goiter: retrospective study of 52 operations.

PURPOSE: Surgical treatment of substernal goiter occasionally involves sternotomy. Classification and handling of these operations are widely discussed. We aimed to review surgical results after thyroid operations including median sternotomy. METHODS: A retrospective review of all thyroid operations performed in the department from 01.01.95 to 31.12.12. In 55 of 2065 thyroid operations (2.7 %), median sternotomy was performed. All hospital journals of the patients were collected and carefully reviewed. RESULTS: We included 52 of 55 identified patients. Pathologic examinations discovered malignant disease in 4 patients (8 %) and multinodular goiter in 48 patients (92 %). Mean operation time was 4 h and 5 min (n = 48). Mean estimated blood loss was 464 ml (n = 48). Blood transfusion was given in nine operations (17 %). Median duration of postoperative hospitalization was 7 days (range 4-27 days). Pulmonary complications occurred in 11 patients (21 %): six with pneumonia or atelectasis, three with pneumothorax, and two with pleural effusion. Three patients (6 %) had postoperative hypocalcaemia (permanent in two patients (4 %)). Three patients (6 %) had transient voice changes. Permanent vocal cord paresis was not observed in this series of patients. CONCLUSION: Thyroid operations with sternotomy are complicated procedures accompanied with considerable pulmonary complications. In spite of a large invasive procedure, the risk of hypoparathyroidism or recurrent laryngeal nerve injury was not increased.

Understanding coupling between bone resorption and formation: are reversal cells the missing link?

Bone remodeling requires bone resorption by osteoclasts, bone formation by osteoblasts, and a poorly investigated reversal phase coupling resorption to formation. Likely players of the reversal phase are the cells recruited into the lacunae vacated by the osteoclasts and presumably preparing these lacunae for bone formation. These cells, called herein reversal cells, cover >80% of the eroded surfaces, but their nature is not identified, and it is not known whether malfunction of these cells may contribute to bone loss in diseases such as postmenopausal osteoporosis. Herein, we combined histomorphometry and IHC on human iliac biopsy specimens, and showed that reversal cells are immunoreactive for factors typically expressed by osteoblasts, but not for monocytic markers. Furthermore, a subpopulation of reversal cells showed several distinctive characteristics suggestive of an arrested physiological status. Their prevalence correlated with decreased trabecular bone volume and osteoid and osteoblast surfaces in postmenopausal osteoporosis. They were, however, virtually absent in primary hyperparathyroidism, in which the transition between bone resorption and formation occurs optimally. Collectively, our observations suggest that arrested reversal cells reflect aborted remodeling cycles that did not progress to the bone formation step. We, therefore, propose that bone loss in postmenopausal osteoporosis does not only result from a failure of the bone formation step, as commonly believed, but also from a failure at the reversal step.

Increased trabecular volumetric bone mass density in Familial Hypocalciuric Hypercalcemia (FHH) type 1: a cross-sectional study.

Familial Hypocalciuric Hypercalcaemia (FHH) Type 1 is caused by an inactivating mutation in the calcium-sensing receptor (CASR) gene resulting in elevated plasma calcium levels. We investigated whether FHH is associated with change in bone density and structure. We compared 50 FHH patients with age- and gender-matched population-based controls (mean age 56 years, 69 % females). We assessed areal BMD (aBMD) by DXA-scans and total, cortical, and trabecular volumetric BMD (vBMD) as well as bone geometry by quantitative computed tomography (QCT) and High-Resolution peripheral-QCT (HR-pQCT). Compared with controls, FHH females had a higher total and trabecular hip vBMD and a lower cortical vBMD and hip bone volume. Areal BMD and HRpQCT indices did not differ except an increased trabecular thickness and an increased vBMD at the transition zone between cancellous and cortical bone in of the tibia in FHH. Finite element analyses showed no differences in bone strength. Multiple regression analyses revealed correlations between vBMD and P-Ca(2+) levels but not with P-PTH. Overall, bone health does not seem to be impaired in patients with FHH. In FHH females, bone volume is decreased, with a lower trabecular volume but a higher vBMD, whereas cortical vBMD is decreased in the hip. This may be due to either an impaired endosteal resorption or corticalization of trabecular bone. The smaller total bone volume suggests an impaired periosteal accrual, but bone strength is not impaired. The findings of more pronounced changes in females may suggest an interaction between sex hormones and the activity of the CaSR on bone.

Muscle function is impaired in patients with "asymptomatic" primary hyperparathyroidism.

BACKGROUND: Patients with "asymptomatic" primary hyperparathyroidism (PHPT) often describe improvement after surgery. METHODS: We evaluated muscle and balance function, quality of life (QoL), and well-being in 58 PHPT patients and 58 population-based matched controls in a cross-sectional study. We tested whether patients considered "asymptomatic" according to international guidelines have functional impairment. RESULTS: Mean age of the patients and controls was 59 years, and 47 (81 %) were women. Patients had higher levels of plasma PTH and ionized calcium. Creatinine and 25-hydroxyvitamin D levels did not differ between groups. Altogether, 16 (28 %) patients were "asymptomatic." Compared with controls, PHPT was associated with significantly lower QoL in all eight domains of the short form-36 questionnaire, lower well-being (WHO Five Well-Being Index; p < 0.001), and impaired postural stability during normal standing with eyes open (p < 0.05) or closed (p < 0.001). Maximum isometric muscle strength was reduced in both upper (p < 0.01) and lower (p < 0.001) extremities. Physical performance was decreased during 10 repeated chair stands (p < 0.001) and time to walk 3 m forward and back (p < 0.05). Restricting analyses to "asymptomatic" patients showed significantly lower muscle strength at knee extension and flexion and impaired postural stability than in matched controls. CONCLUSIONS: PHPT is associated with deleterious effects on muscles and QoL. Impairments also apply to patients with mild disease, normally considered "asymptomatic." This may explain why "asymptomatic" patients report improvements following surgery. The impaired muscle function may contribute to increased fracture risk independent of bone mineral density.

Autofluorescence-Guided Total Thyroidectomy in Low-Volume, Nonparathyroid Institutions.

Importance: Hypoparathyroidism following thyroid surgery is a serious complication that occurs frequently when surgery is performed by low-volume thyroid surgeons without experience in parathyroid surgery. Objective: To evaluate the occurrence of hypoparathyroidism following total thyroidectomy after the introduction of autofluorescence in low-volume, nonparathyroid institutions. Design, Setting, and Participants: This prospective, multicenter cohort study, with a follow-up period of up to 1 year, was conducted in Denmark at 2 low-volume nonparathyroid institutions between January 2021 and November 2023. All adult patients referred for total thyroidectomy were assessed for eligibility (n = 90). Only patients with no history of thyroid surgery were considered (n = 89). Patients who only underwent lobectomy (n = 6) or declined to participate (n = 5) were excluded. All included patients completed follow-up. The prospective cohort was compared with a historical cohort of successive patients undergoing primary total thyroidectomy from 2016 to 2020 (before autofluorescence was available). Intervention: Included patients underwent autofluorescence-guided total thyroidectomy. Main outcomes and Measures: Rate of hypoparathyroidism. Immediate hypoparathyroidism was defined as the need for active vitamin D postoperatively, whereas permanent hypoparathyroidism was considered when there still was a need for active vitamin D 1 year after surgery. Results: Seventy-eight patients underwent autofluorescence-guided surgery (mean [SD] age, 55.6 [13.1] years; 67 [86%] female) and were compared with 89 patients in the historical cohort (mean [SD] age, 49.7 [12.8] years; 78 [88%] female). The rate of immediate hypoparathyroidism decreased from 37% (95% CI, 27%-48%) to 19% (95% CI, 11%-30%) after the introduction of autofluorescence (P = .02). Permanent hypoparathyroidism rates decreased from 32% (95% CI, 22%-42%) to 6% (95% CI, 2%-14%) (P < .001), reaching 0% at the end of the study. More parathyroid glands were identified with autofluorescence (75% [95% CI, 70%-80%] vs 61% [95% CI, 56%-66%]) (P < .001) and less parathyroid glands were inadvertently excised (4% [95% CI, 1%-11%] vs 21% [95% CI, 13%-31%]) (P = .001). Conclusions and Relevance: In this cohort study of autofluorescence-guided thyroid surgery in low-volume, nonparathyroid institutions, the use of autofluorescence was associated with a significant decrease in both immediate and permanent hypoparathyroidism. When autofluorescence was used, hypoparathyroidism rates were comparable with those of high-volume surgeons who also perform parathyroid surgery.

Hypoparathyroidism following total thyroidectomy: high rates at a low-volume, non-parathyroid institution.

Background: Hypoparathyroidism following total thyroidectomy is globally the most common complication to thyroid surgery. The reported complication rates vary widely and might be highly dependent on the surgical experience. In this study we aimed to evaluate the rate of hypoparathyroidism following primary total thyroidectomy at a low-volume institution that only performs thyroid surgery and does not have any experience with parathyroid surgery. Methods: Retrospective cohort study. All patients undergoing primary total thyroidectomy at the ENT-Department, Goedstrup Hospital, Denmark, over a 5-year period (2016-2020) were identified through the procedure codes for total thyroidectomy. Medical records, pathology reports, biochemical and medical histories were fully assessed for each patient. The primary endpoint was the rate of hypoparathyroidism- both immediate and permanent. Secondary outcomes were parathyroid gland identification rates, rates of parathyroid gland autotransplantation, and rates of inadvertent parathyroid gland excision. Results: A total of 89 patients were included in the final analysis. A total of 33 patients (37.1%) experienced immediate hypoparathyroidism following surgery, while 30 patients (33.7%) still were on active vitamin D two months postoperatively. One year following surgery, 28 patients (31.5%) were still on active vitamin D and were considered as having permanent hypoparathyroidism. Sixty-one percent of the parathyroid glands were identified intraoperatively, and 19% of the patients experienced parathyroid autotransplantation. Inadvertent parathyroid gland excision occurred for 21% of the patients and was associated with a significantly increased risk of permanent hypoparathyroidism (RR = 2.99; 95% CI: 1.36 - 6.62, p = 0.005). Conclusion: Both transient and permanent hypoparathyroidism following total thyroidectomy at a low-volume, non-parathyroid institution occurred with much higher frequencies than previously reported. The elevated rates were most likely due to the low-volume, non-parathyroid nature of the surgeons which in part was mirrored in low parathyroid gland identifications rates, and high rates of autotransplantation and inadvertent parathyroid gland excision.

Validation of the Bethesda System for Reporting Thyroid Cytopathology in a Danish tertiary centre.

INTRODUCTION: The Bethesda System for Reporting Thyroid Cytopathology (BSRTC) is used to categorise thyroid fine-needle aspiration (FNA). The aim of this study was to validate the BSRTC in a consecutive cohort and to evaluate the derived management in terms of performing repeat FNA or thyroid surgery. METHODS: Results of thyroid FNAs assessed at the Department of Pathology, Aarhus University Hospital, in the period 2016-2019 were retrieved from The Danish Pathology Registry. FNA category according to the BSRTC along with the histological diagnosis (if available) were linked to the individual patient. RESULTS: In total, 3,669 biopsies were included from 2,873 thyroid nodules in 2,547 patients. Repeat FNA was performed in 23.6% of nodules. The majority of primary FNAs were Benign (BSRTC II; 52.4%). Non-diagnostic (ND) (BSRTC I) was found in 26.3% and BSRTC III-VI were found in 3.6-7.5%. Compared with the first with the last FNA, the frequency of Benign (BSRTC II) increased (61.3%), whereas the frequency of ND (BSRTC I) decreased (14.8%). Surgery was performed in 38.2% (n = 1,097) of nodules. The malignancy rate of 11.5% correlated positively with the BSRTC category, being 2.8% in Benign (BSRTC II) and 95.7% in Malignant (BSRTC VI). CONCLUSIONS: The malignancy rates in the BSRTC categories were in accordance with reports from other countries. Since the BSRTC ensures a standardised and concise communication of cytopathology assessments, application of the BSRTC for thyroid nodule management in a Danish setting is recommended. FUNDING: None. TRIAL REGISTRATION: Not relevant.

BMD improvements after operation for primary hyperparathyroidism.

PURPOSE: This study aims to quantify bone mineral density (BMD) changes following surgery in patients with primary hyperparathyroidism (PHPT) and to assess their relationship with clinical and biochemical variables. METHODS: A historic cohort of 236 PHPT patients with DXA scans pre- and 1-year postoperatively, clinical data, and biochemical data was analyzed. RESULTS: The mean age was 60 years (range 19-86) and 81 % of the patients were women. A significant postoperative 2.6 % (95 % CI, 2.1; 3.1) increase in lumbar spine BMD was seen. The increase in BMD was positively associated with preoperative plasma PTH (p = 0.002), Ca(2+) (p < 0.001), and alkaline phosphatase (p = 0.014). Hip BMD increased 1.5 % (1.1; 1.9). The increase in BMD was positively associated with preoperative plasma PTH (p = 0.005) and Ca(2+) (p < 0.001) and inversely associated with plasma creatinine (p = 0.004) and age (p = 0.018). Total forearm BMD did not change significantly (-0.2 % (-0.5; 0.1)). An increase in forearm BMD was seen in 38 % of all patients, and the changes were positively associated with plasma PTH (p < 0.001) and Ca(2+) (p = 0.009). In all 91 patients with mild PHPT (plasma Ca(2+) < 1.45 mmol/l), there was a significant postoperative increase in spine BMD (1.9 % (1.2; 2.7)) and in hip BMD (1.0 % (0.4; 1.6)), but not in the forearm BMD (-0.3 % (-0.7; 0.2)). The postoperative BMD gain was higher in the hip and forearm in patients operated for adenomas compared with patients treated for hyperplasia. CONCLUSIONS: We found significant postoperative BMD improvements both at the hip and the spine. BMD improvements were also significant in mild cases. At all scan sites, there were positive associations between preoperative plasma PTH levels and postoperative BMD increases. The measured BMD changes may mainly be due to a decrease in PTH-induced bone turnover with refilling of the remodeling space.