Parathyroid Hormone Levels Research Articles

Risk Factors for Transient and Permanent Hypoparathyroidism Following Thyroidectomy: A Comprehensive Review.

Hypoparathyroidism is a common complication following thyroidectomy, resulting in significant disturbances in calcium homeostasis due to low parathyroid hormone (PTH) levels. This comprehensive review examines the risk factors associated with transient and permanent hypoparathyroidism post-thyroidectomy, emphasizing surgical, patient-related, and perioperative factors. Transient hypoparathyroidism, characterized by temporary hypocalcemia resolving within weeks to months, is often managed with short-term calcium and vitamin D supplementation. In contrast, permanent hypoparathyroidism persists beyond six months post-surgery, necessitating lifelong supplementation and potentially PTH replacement therapy. The review delves into the anatomy and physiology of the parathyroid glands, mechanisms leading to hypoparathyroidism, and incidence rates. Surgical factors such as the extent of thyroidectomy, surgeon expertise, and intraoperative parathyroid gland preservation are critical in determining the risk of hypoparathyroidism. Patient factors, including age, sex, pre-existing conditions, and perioperative management, influence outcomes. Diagnostic and monitoring strategies, along with management protocols for both transient and permanent hypoparathyroidism, are discussed. Prevention strategies, emerging research, future surgical techniques, and intraoperative monitoring directions are highlighted to improve clinical outcomes. This review aims to enhance understanding, inform surgical practices, and optimize postoperative care to minimize the incidence and impact of hypoparathyroidism in thyroidectomy patients.

Recurrent Seizures in a Patient with Primary Hypoparathyroidism

Primary hypoparathyroidism is a rare disorder that presents with various psychiatric and neurological symptoms. A 50-year-old female patient visited hospital due to recurrent seizures. Despite treatment with phenytoin and diazepam, her seizures persisted. Laboratory tests revealed hypocalcemia, hyperphosphatemia, and decreased intact parathyroid hormone level. Following treatment with valproic acid and calcium supplementation, her seizures ceased. Thorough examination including laboratory tests play a crucial role in the accurate diagnosis of primary hypoparathyroidism in a patient with recurrent seizures.

Abnormalities of serum magnesium levels in dialysis patients undergoing parathyroidectomy.

In primary hyperparathyroidism, postoperative hypocalcemia can be exacerbated by magnesium deficiency. However, the significance of magnesium homeostasis in surgery for secondary hyperparathyroidism is unknown. In this study, 268 consecutive adult patients on renal replacement therapy who underwent parathyroidectomy for secondary hyperparathyroidism were included for analysis. We found that about one fifth presented with hypomagnesemia (5.6%) or hypermagnesemia (14.6%). Hypomagnesemia was associated with lower calcium levels and longer postoperative hospital stays. Hypermagnesemia was associated with higher calcium-phosphorus products and lower parathyroid hormone levels. In multivariate analysis, patient age, alkaline phosphatase, and osteocalcin were independent predictors of prolonged stay after parathyroidectomy. There was a positive correlation between serum magnesium levels and severity of itching in these patients. Calcium-phosphorus products and serum magnesium levels were independently associated with pruritus. In conclusion, magnesium abnormalities play a minor role in hungry bone syndrome after parathyroidectomy for secondary hyperparathyroidism. Patients with higher serum magnesium levels had greater severity of pruritus.

Opportunities to improve the diagnosis and treatment of primary hyperparathyroidism: retrospective cohort study.

Although primary hyperparathyroidism (PHPT) is readily diagnosed biochemically and can be cured with low-risk surgery, it is often underrecognized and undertreated. Our objectives were to characterize, within our health system, how often patients with hypercalcemia were evaluated for PHPT and how often patients with PHPT underwent definitive treatment with parathyroidectomy. Ambulatory patients aged 18 years or older seen at our health system between January 2018 and June 2023 with chronic hypercalcemia were identified from the medical record. After excluding causes of secondary hyperparathyroidism, the proportion of patients with parathyroid hormone (PTH) tests was calculated. Among patients with biochemical evidence of PHPT, the proportion of patients who underwent parathyroidectomy was calculated. Multivariable logistic regression was used to identify factors associated with an evaluation for PHPT and, separately, with parathyroidectomy. Of 7,675 patients with chronic hypercalcemia, 3,323 (43.3%) had a PTH test obtained within 6 months. An age between 40-49 vs. <30 years [(odds ratio (OR) =3.2; 95% confidence interval (CI): 1.8-5.6; P<0.001], a serum calcium level between 11.6-12.0 vs. <11.0 mg/dL (OR =3.9; 95% CI: 3.2-4.7; P<0.001), and osteoporosis (OR =3.1; 95% CI: 2.7-3.5; P<0.001) were associated with an evaluation for PHPT. Among those with PTH levels, 1,327 (39.9%) had PHPT but only 916 (69.0%) were recognized. Three hundred and forty-five (26.0%) patients with PHPT underwent parathyroidectomy. An increasing number of surgical indications was associated with parathyroidectomy (P<0.001), though overall rates remained less than 40%. Among indications for surgery, including age and serum total calcium level, only osteoporosis was associated with parathyroidectomy (OR =2.0; 95% CI: 1.4-2.8; P<0.001). In this study, more than half of patients with chronic hypercalcemia were not evaluated for PHPT. Among patients with biochemical evidence of PHPT, one-third were unrecognized and only one-in-four received curative treatment. Opportunities to improve the management of PHPT exist within our large integrated health system.

Saline suppression testing-induced hypocalcemia and implications for clinical interpretations.

Extracellular calcium critically regulates physiologic aldosterone production. Moreover, abnormal calcium flux and signaling are involved in the pathogenesis of the majority of primary aldosteronism cases. We investigated the influence of the saline suppression test (SST) on calcium homeostasis in prospectively recruited participants (n = 86). During SST, 100% of participants had decreases in serum calcium, with 48% developing frank hypocalcemia. Serum calcium declined from 2.30 ± 0.08 mmol/L to 2.13 ± 0.08 mmol/L (P < .001) with parallel increases in parathyroid hormone from 6.06 ± 2.39 pmol/L to 8.13 ± 2.42 pmol/L (P < .001). In contrast, serum potassium and bicarbonate did not change, whereas eGFR increased and serum glucose decreased (P < .001). Lower body surface area (translating to greater effective circulating volume expansion during SST) was associated with greater reductions in (β = .33, P = .001), and absolutely lower, serum calcium levels (β = .25, P = .001). When evaluating clinically-relevant diagnostic thresholds, participants with post-SST aldosterone levels <138 pmol/L had lower post-SST calcium and 25-hydroxyvitamin D levels (P < .05), and higher post-SST parathyroid hormone levels (P < .05) compared with those with post-SST aldosterone levels >277 pmol/L. SST uniformly decreases serum calcium, which is likely to be due to the combination of variable dilution, increased renal clearance, and vitamin D status. These acute reductions in bioavailable calcium are associated with lower post-SST aldosterone. Given the critical role of extracellular calcium in regulating aldosterone production, these findings warrant renewed inquiry into the validity of SST interpretations for excluding primary aldosteronism.

Feasibility and Safety of transoral robotic parathyroidectomy: Initial experience with a new approach for parathyroid surgery

BackgroundWe present the initial outcomes of transoral robotic parathyroidectomy (TORP) using the transoral vestibular approach in patients with primary hyperparathyroidism (PHPT). MethodA retrospective case series analysis was performed on patients diagnosed with PHPT between October 2016 and July 2019 who underwent transoral robotic surgery for parathyroidectomy. ResultsThirteen patients (five males and eight females) successfully underwent TORP at our institution from October 2016 to July 2019. Eight patients underwent TORP alone, and five underwent TORP combined with transoral robotic thyroidectomy for papillary thyroid carcinoma. No intra- or postoperative complications were observed. Serum levels of parathyroid hormone, total calcium, and ionized calcium decreased to normal postoperatively and continued to decrease during the follow-up period. ConclusionThis study suggests that TORP holds promise for the treatment of patients with PHPT with the advantages of the robotic procedure, including dynamic visualization and meticulous dissection.

Cystinosis-associated metabolic bone disease across ages and CKD stages 1-5D/T.

The pathophysiology of cystinosis-associated metabolic bone disease is complex. We hypothesized a disturbed interaction between osteoblasts and osteoclasts. Binational cross-sectional multicenter study. Hospital clinics. One hundred and three patients with cystinosis (61% children) with chronic kidney disease (CKD) stages 1-5D/T. Ten key bone markers. Skeletal complications occurred in two-thirds of the patients, with adults having a five-fold increased risk compared to children. Patients with CKD stages 1-3 showed reduced z-scores for serum phosphate and calcium, suppressed fibroblast growth factor 23 (FGF23) and parathyroid hormone levels in conjunction with elevated bone-specific alkaline phosphatase levels. Serum phosphate was associated with estimated glomerular filtration rate, combined phosphate and active vitamin D treatment, and native vitamin D supplementation, while serum calcium was associated with age and dosage of active vitamin D. Sclerostin was generally elevated in children, and associated with age, FGF23 levels, and treatment with active vitamin D and growth hormone. The osteoclast marker tartrate-resistant acid phosphatase 5b was increased, and associated with age and treatment with active vitamin D. The ratio of soluble ligand of receptor activator of nuclear factor-κB (sRANKL) and osteoprotegerin (OPG), a surrogate for the regulation of osteoclastogenesis by osteoblasts, was decreased and associated with phosphate and 1,25(OH)2D3 levels. These changes were only partly corrected after transplantation. Bone health in cystinosis deteriorates with age, which is associated with increased osteoclast activity despite counterregulation of osteoblasts via OPG/RANKL, which in conjunction with elevated sclerostin levels and persistent rickets/osteomalacia may promote progressive bone loss.

Understanding delays to parathyroidectomy: A mixed-methods approach

BackgroundPatients from ethnic and racial minority groups with primary hyperparathyroidism may have greater time delays to curative parathyroidectomy. Contributing factors are unclear. MethodsThis was a sequential mixed-methods study. The quantitative phase was a retrospective chart review of adults with primary hyperparathyroidism who underwent parathyroidectomy between 2015 and 2020, collecting demographic and clinical data. Social vulnerability of the patients' residential area, measured with the Social Vulnerability Index, and relevant clinical time intervals were calculated. A multivariable analysis of factors associated with greater time intervals was performed. The qualitative phase involved semistructured interviews with endocrinologists, analyzed inductively for themes. ResultsOn chart review of 1,083 patients, the median age was determined to be 61 years and 856 (79%) were female. Six hundred twenty-eight (57.9%) were non-Hispanic White and 456 (42.1%) were Hispanic ethnicity or Asian, Pacific Islander, Black, Native American, Other or Unknown race. Patients of Hispanic ethnicity, or Asian or Pacific Islander, Black, Native American, Other or Unknown race were more likely than non-Hispanic White patients to live in the most socially vulnerable areas (19.3% vs 5.9%, P < .01) and had greater time intervals than non-Hispanic White patients between index hypercalcemia and first parathyroid hormone level, surgical referral, or parathyroidectomy (all P < .05). On multivariable analysis, age (coefficient 7.9, 95% CI 2.8–13.0) and living in the most socially vulnerable areas (coefficient 297.9, 95% CI 87–508.7) were associated with greater days between index hypercalcemia and parathyroidectomy. In the study's qualitative phase, identified themes for reasons for care delays included socioeconomic, nonsocioeconomic patient, and nonsocioeconomic nonpatient factors. ConclusionCare delays are driven by a combination of socioeconomic and nonsocioeconomic factors.

Clinical and epidemiologic characteristics of hospitalized oncological patients with hypercalcemia: alongitudinal, multicenter study.

There are few studies that have analyzed the characteristics of hypercalcemia in hospitalized oncological patients. Our objectives were to describe the clinical characteristics of hospitalized patients with paraneoplastic hypercalcemia and to identify prognostic variables for mortality. This was an observational, longitudinal, retrospective, and bicentric study. It included adult patients admitted to two hospitals in Málaga, Spain (2014-2018). The minimum follow-up period was 2years or until death. Atotal of 154 patients were included; the majority (71.4%) were admitted to the internal medicine department. The median follow-up was 3.5weeks (interquartile range [IQR] 1.1-11.5). The mean (standard deviation) age was 67.6 (12.3) years, with apredominance of males (58.4%). The median (IQR) serum calcium at admission was 13.2 (11.8-14.6) mg/dl. The most common neoplasms were pulmonary (27.3%), hematologic (23.4%), urological (13%), and breast (12.3%). Furthermore, 56.5% of cases had aknown history of neoplasia at the time of diagnosis. The parathyroid hormone (PTH) level was determined in 24%; of these, 10.8% had elevated levels. In all, 95.5% of patients died during follow-up. The median survival was 3.4weeks (95% confidence interval 2.6-4.3). Factors associated with higher mortality were age, serum calcium at admission, previous history of neoplasia, etiology other than multiple myeloma, and noncorrection of hypercalcemia. In hospitalized patients, paraneoplastic hypercalcemia was associated with high short-term mortality. Several factors associated with aworse prognosis were identified in these patients.

Association between Chronic Kidney Disease-Mineral and Bone Disorder Biomarkers and Symptom Burden in Older Patients with Advanced Chronic Kidney Disease: Results from the EQUAL Study.

Patients with advanced chronic kidney disease (CKD) develop numerous symptoms, with a multifactorial origin. Evidence linking mineral disorders (CKD-MBD) and uremic symptoms is scant and mostly limited to dialysis patients. Here we aim to assess the association between CKD-MBD and symptom burden in non-dialysis CKD patients. We used data from the European Quality study, which includes patients aged ≥65 with eGFR ≤20 ml/min/1.73m2 from six European countries, followed up to five years. We used generalized linear mixed-effect models to determine the association between repeated measurements of parathyroid hormone (PTH), phosphate and calcium with the overall symptom number (0-33), the overall symptom severity (0-165), and the presence of 33 CKD-related symptoms. We also analyzed subgroups by sex, age, and diabetes mellitus, and assessed effect mediation and joint effects between mineral biomarkers. The 1396 patients included in the study had a mean of 13±6 symptoms at baseline, with a median overall severity score of 32 (IQR 19-50). The association between PTH levels and symptom burden appeared U-shaped with a lower symptom burden found for mild-to-moderately increased PTH levels. Phosphate and calcium were not independently associated with overall symptom burden. The highest symptom burden was found in patients with a combination of both severe hyperparathyroidism and severe hyperphosphatemia (+2.44 symptoms (0.50, 4.38), P=0.01). The association of both hypocalcemia and hyperphosphatemia with symptom burden seemed to differ by sex and age. In older patients with advanced CKD not on dialysis, mild-to-moderately increased PTH was associated with a lower symptom burden, although the effect size was relatively small (less than one symptom). Neither phosphate nor calcium were associated with the overall symptom burden, except for the combination of severe hyperphosphatemia and severe hyperparathyroidism which was associated with an increased number of symptoms.

Beneficial Effects of Ketoanalogues on the Evolution of Renal Function and Bone Mineral Disorders in Patients with Advanced Chronic Kidney Disease: A Pilot Study.

The supplementation with Ketoanalogues in patients on very low-protein diets has shown a favorable effect on the evolution of renal function. The aim of the present study was to evaluate the progression of renal function in advanced chronic kidney disease patients on a low-protein diet (&lt;0.8 g/kg/d) with or without additional Ketoanalogues. The primary criterion is the evolution of the renal function at 6, 12, and 24 months for the two groups. The secondary criteria comprise the evolution of the body weight, mean blood pressure, 24-h proteinuria, salt and protein consumption, energy consumption, hemoglobin levels, serum albumin, prealbumin, C-reactive protein, liver function tests, serum electrolyte and phosphate levels, parathormone as well as calcium levels at the same time periods. There was a significant nephroprotective effect of the Ketoanalogues after 12 and 24 months with no differences in the protein consumption between the two groups. Mean blood pressure, hemoglobin levels, 24-hour proteinuria, serum electrolyte, liver function tests, salt and protein consumption, and serum albumin and prealbumin did not present any significant differences. Serum bicarbonate and calcium levels were higher while serum phosphate and parathormone levels were lower in the Ketoanalogue group at all follow-up time points. During the 24-month follow-up period, 4 patients from the Ketoanalogue group and 8 patients from the control group quit the study. A low-protein diet supplemented with Ketoanalogues exerts significant nephroprotective effects and better bone mineral metabolism parameters compared to a low-protein diet only.

68Ga-Trivehexin PET/CT: a promising novel tracer for primary hyperparathyroidism

IntroductionThis study aims to assess 68Ga-Trivehexin PET/CT for detecting hyperfunctioning parathyroid tissue in comparison to [99mTc]Tc-MIBI scintigraphy-SPECT/CT (MIBI scan) in patients with primary hyperparathyroidism (PHPT).MethodsThe cohort comprised 13 patients diagnosed with PHPT based on biochemical analyses, including serum calcium, phosphorus, and parathyroid hormone (PTH) levels. Each participant underwent cervical ultrasonography, MIBI scan, and 68Ga-Trivehexin PET/CT imaging. Complementary 4D-CT and [18F]fluorocholine PET/CT were conducted in 7 patients. Ten lesions of 7 patients underwent PTH wash-out (WO) procedure. 68Ga-Trivehexin PET/CT findings were compared with other modalities and PTH-WO results.ResultsTen patients had sporadic PHPT, while 3 were diagnosed with MEN-1 syndrome-associated PHPT. One patient did not have any identifiable parathyroid lesion across the imaging modalities. On a patient-based analysis, MIBI scan and 68Ga-Trivehexin PET/CT identified parathyroid lesions in 10 and 11 patients, respectively. However, 68Ga-Trivehexin PET/CT detected 7 additional parathyroid lesions that were negative on the MIBI scan. Consequently, 17 lesions were identified and confirmed as hyperfunctioning parathyroid tissue through imaging, PTH-WO, or a combination of both modalities. In lesion-based evaluation, 68Ga-Trivehexin identified 16 lesions compared to 10 by MIBI scan, resulting in a detection rate of 94.1% and 58.8%, respectively. Notably, in three patients who underwent [18F]fluorocholine PET/CT, no lesions were detected; yet 68Ga-Trivehexin PET/CT successfully identified parathyroid lesions in two of these patients.ConclusionOur study provides the first evidence that 68Ga-Trivehexin PET/CT can effectively identify hyperfunctioning parathyroid tissue with a high detection rate warranting further investigations to comprehensively explore its potential in PHPT management.

Lower Parathyroid Hormone Levels are Associated With Reduced Fracture Risk in Japanese Patients on Hemodialysis

Secondary hyperparathyroidism (SHPT) affects bone metabolism and may lead to bone fragility. However, there is conflicting evidence as to whether parathyroid hormone (PTH) levels are associated with fracture risk and whether the relationship is linear or U-shaped. We examined the association between PTH levels and the risk of any fracture and site-specific fractures in a nationwide cohort of 180,333 patients on hemodialysis. We also examined the association between the percent change in PTH levels during the preceding 1 year and subsequent fracture. At baseline, the median intact PTH level was 141 pg/ml (interquartile range, 78-226 pg/ml). During 1 year of follow-up, there were a total of 3762 fractures requiring hospitalization (1361 hip, 551 vertebral, and 1850 other). In an adjusted analysis, higher baseline PTH levels were associated with an incrementally increased risk of any fracture (odds ratio [OR] per doubling of intact PTH, 1.06; 95% confidence interval, 1.03-1.09). The association between PTH levels and fracture risk was more pronounced for hip fractures but not found for vertebral fractures. The absolute risk difference associated with higher PTH levels appeared to be more pronounced in older individuals, females, and those with lower body mass index (BMI). Change in PTH levels was also associated with fracture risk: the adjusted OR for fracture decreased linearly with decreasing PTH levels over 1 year, regardless of the preceding PTH levels. Lower PTH levels are associated with a graded reduction in fracture risk. Further studies are needed to determine whether intensive PTH control reduces fracture risk.

Acute pancreatitis and refractory hypercalcemia in the third trimester caused by parathyroid carcinoma

BackgroundHypercalcemia can be a rare contributor to acute pancreatitis (AP) in pregnancy. This is primarily due to primary hyperparathyroidism (PHPT), resulting from parathyroid carcinoma. We exhibited a case report to analyze the diagnosis and treatment during the onset of hypercalcemia-induced AP.Case presentationA 32-year-old primigravida presented with acute pancreatitis near full-term gestation. Following a cesarean delivery, there was a reduction in serum amylase and peripancreatic exudate, but her serum calcium concentrations persistently elevated over 4.0 mmol/L. Interventions to lower the hypercalcemia were only temporarily effective, until a high serum parathyroid hormone (PTH) concentration of 1404 pg/mL was detected. Ultrasound revealed a 31 mm × 24 mm hypoechoic oval nodule in the left lower lobe of the thyroid gland. She underwent a parathyroidectomy, resulting in a dramatic decrease in serum PTH level, from preoperative levels of 2051 pg/mL to 299 pg/mL just 20 minutes after removal. Similarly, her serum calcium declined from 3.82 mmol/L to 1.73 mmol/L within 24 hours postoperatively. The final histopathology suggested parathyroid carcinoma.ConclusionWhen refractory hypercalcemia is present, serum PTH levels should be measured to determine PHPT. Parathyroidectomy is the optimal strategy for alleviating hypercalcemia and clarifying the underlying pathology.

Delayed Diagnosis and Late Presentation of Primary Hyperparathyroidism in Somalia: A Case Report and Literature Review

Primary hyperparathyroidism (PHPT) is a rare endocrine disorder characterized by elevated serum calcium levels due to overproduction of parathyroid hormone (PTH). While parathyroid adenomas are the most common cause, they can present diagnostic and management challenges, especially in resource-limited settings. We present the case of a 51-year-old Somali female with a six-year history of generalized weakness, fatigue, and nonspecific abdominal pain. Laboratory investigations revealed elevated PTH levels (231 ng/ml) and hypercalcemia (14 mg/dl), consistent with PHPT. Cervical ultrasound identified a hypoechoic hypervascular solitary lesion suggestive of a parathyroid adenoma. The patient underwent a successful parathyroidectomy, resulting in the normalization of serum calcium levels and symptomatic relief. Histopathological examination confirmed the diagnosis of parathyroid adenoma. This case underscores the importance of early recognition and intervention in PHPT, particularly in underserved regions where healthcare resources may be limited. Efforts to raise awareness, provide training for healthcare workers, and improve access to diagnostic and treatment modalities are crucial in optimizing outcomes for patients with PHPT.

Clinical effect of nursing methods integrating health belief models on self-care of maintenance hemodialysis patients: A retrospective study.

This study aimed to explore the clinical effectiveness of nursing methods that incorporate health belief models on the self-care practices of maintenance hemodialysis patients. The objective was to enhance patients' health beliefs, strengthen their healthy behaviors and habits, improve their unhealthy daily behaviors, and provide robust theoretical and practical foundations for future nursing practices in this area. A retrospective analysis was conducted on 150 hemodialysis patients from our hospital, from January 2019 to February 2023. The participants were divided into 2 groups: a control group (N = 75) using routine nursing methods, and an experimental group (N = 75) using methods integrated with health belief models. Both groups were comparable in terms of demographic and baseline clinical characteristics such as gender, marital status, age, education level, total scores of self-care ability, and dialysis duration, with no significant differences observed (P > .05). Data collection tools included a general information questionnaire and a self-care ability scale, and clinical effectiveness was measured through specific indicators such as parathyroid hormone, blood phosphorus, urea, potassium, calcium, and IWGR%. Post-intervention, the experimental group demonstrated significant improvements in self-care capabilities across various dimensions and most clinical indicators compared to the control group, with the exception of parathyroid hormone and blood urea levels. The study concludes that integrating health belief models into nursing practices significantly enhances the self-care abilities of maintenance hemodialysis patients, improves several clinical parameters, and holds promise for fostering better patient outcomes and guiding future clinical nursing practices.

Activation of the Calcium-Sensing Receptor by a Subfraction of Amino Acids Contained in Thyroid Drainage Fluid.

Hypoparathyroidism is a common sequela of thyroid surgery; in this study, we aimed at exploring the pathogenesis behind it. The following premises suggest that wound fluid might be a causative agent. (i) Parathyroid hormone secretion is under feedback control by the calcium-sensing receptor, which responds to a diverse array of activating ligands. (ii) Postoperative hypoparathyroidism arises from a secretory deficiency of the parathyroid glands. Even in patients later unaffected by hypoparathyroidism, parathyroid hormone levels drop within hours after surgery. (iii) Wound fluid is bound to enter the tissue around the thyroid bed, where the parathyroid glands are located. Its composition is shaped by a series of proteolytic reactions triggered by wounding. Using thyroid drainage as a surrogate, we addressed the possibility that wound fluid contains compounds activating the calcium-sensing receptor. Drainage fluid ultrafiltrate was found to be rich in amino acids, and on separation by HPLC, compounds activating the calcium-sensing receptor partitioned with hydrophilic matter that rendered buffer acidic. The data show that glutamate and aspartate at millimolar concentrations supported activation of the calcium-sensing receptor, an effect contingent on low pH. In the presence of glutamate/aspartate, protons activated the calcium-sensing receptor with a pH50 of 6.1, and at pH 5, produced maximal activation. This synergistic mode of action was exclusive; glutamine/asparagine did not substitute for the acidic amino acids, nor did Ca2+ substitute for protons. NPS-2143, a negative allosteric receptor modulator completely blocked receptor activation by glutamate/aspartate and by fractionated drainage fluid. Thus, wound fluid may be involved in suppressing parathyroid hormone secretion.

Comparing early and delayed [99mTc]Tc-MIBI SPECT/CT parathyroid scans: agreement, confidence levels, and clinical predictive factors

BackgroundParathyroid scan is an important imaging modality for localizing hyperfunctioning parathyroid tissue in patients with hyperparathyroidism. Unfortunately, whether early or delayed timing is the optimal protocol for [99mTc]Tc-MIBI SPECT/CT parathyroid remains under debate. This study aimed to evaluate the agreement and compare the confidence levels of physicians when interpreting early and delayed [99mTc]Tc-MIBI SPECT/CT parathyroid scans. Additionally, it sought to identify clinical factors that related to positive scan result. We conducted a prospective study where the early and delayed [99mTc]Tc-MIBI SPECT/CT was separately interpreted as either positive or negative. Furthermore, these interpretations were categorized based on whether they fell within more or less confidence levels of the readers and were correlated with clinical information.ResultsWe enrolled 39 patients with hyperparathyroidism with 158 possible locations of parathyroid glands. The per-location agreement between the early and delayed scans was moderate (concordant rate: 80.3%, Kappa = 0.558), and the per-patient agreement was slight (concordant rate: 71.8%, Kappa = 0.093). The confidence of interpretation was significantly higher for the delayed scans. Calcium supplementation, low serum parathyroid hormone levels, and low serum phosphate levels were associated with positive early scans. High calcium level and high parathyroid hormone levels were associated with positive delayed scans.ConclusionsOur study highlights the impact of the timing of SPECT/CT in [99mTc]Tc-MIBI parathyroid scans. The different confidence levels between early and delayed scans, along with clinical factors, imply that various factors affect parathyroid scan interpretation, and individualized scanning protocols adjusted for specific settings may be needed to optimize the successful localization of hyperfunctioning parathyroid tissue.

Association between tobacco smoke exposure and serum parathyroid hormone levels among US adults (NHANES 2003–2006)

Tobacco smoke exposure has been demonstrated to impede bone remodeling and diminish bone density, yet research regarding its correlation with parathyroid hormone (PTH) remains limited. This study aims to investigate the relationship between tobacco smoke exposure and serum PTH levels in adults aged 20 years and older. This study included 7,641 participants from two cycles of the National Health and Nutrition Examination Survey (NHANES, United States, 2003- 2006). Reflect tobacco smoke exposure through serum cotinine levels, and use an adjusted weighted multivariate linear regression model to test the independent linear relationship between serum cotinine and PTH. Stratified analysis was conducted to validate the sensitivity of the conclusions. Smooth curve fitting and threshold effect analysis were performed to assess the non-linear relationship. After comprehensive adjustment using weighted multivariate regression analysis, a negative correlation was found between serum cotinine and PTH levels. The interaction p-values in subgroup analyses were all greater than 0.05. Moreover, smooth curve fitting indicated a non-linear relationship between serum cotinine and PTH, with a turning point observed. Our research indicates that tobacco smoke exposure is negatively correlated and independent of serum parathyroid hormone levels, indicating that long-term tobacco smoke exposure may lead to parathyroid dysfunction in adults.

Vertebral fractures in patients with CKD and the general population: a call for diagnosis and action.

Vertebral fractures (VFs) are the most common osteoporotic fractures in the general population, and they have been associated with high mortality, decreased quality of life, and high risk of subsequent fractures, especially when recent, multiple, or severe. Currently, VF diagnosis and classification determine fracture risk and the most appropriate anti-osteoporotic treatment. However, VFs are clearly underdiagnosed, especially in patients with chronic kidney disease (CKD), and CKD-associated osteoporosis has been disregarded until recently. VFs are associated with higher morbidity and mortality, and their prevalence and incidence differ depending on the grade of renal dysfunction (CKD G1-G5) and/or the type of renal replacement therapy (dialysis or transplantation). In addition to classical risk factors [such as higher age, female sex, reduced bone mineral density, diabetes and steroid use], various other factors have been associated with an increased risk of VFs in CKD, including CKD grade, haemodialysis vintage, time since renal transplantation, low or high intact parathyroid hormone and phosphate levels, and/or vitamin D and K1 deficiencies. Importantly, several clinical societies have recently modified their algorithms according to the fracture risk classification (including the presence of VFs) and determined the most appropriate anti-osteoporotic treatment for the general population. However, there are no specific guidelines addressing this topic in patients with CKD despite an important paradigm shift regarding the prognostic value of bone mineral density in 2017 after the publication of the CKD-Mineral and Bone Disorder Kidney Disease: Improving Global Outcomes guidelines. A proactive attitude towards diagnosis, treatment, and research is proposed to avoid therapeutic nihilism.