Appropriate and mindful measurement of serum calcitonin in patients with thyroid nodules. A white paper.

Medullary thyroid carcinoma (MTC) is an infrequent thyroid malignancy that is often diagnosed at advanced stage with consequent poor prognosis. Thus, the earlier the diagnosis of MTC, the better the prognosis. Unfortunately, the preoperative detection of MTC remains challenging in clinical practice. In fact, while ultrasound and fine-needle aspiration cytology have suboptimal performance in this context, measuring serum calcitonin (Ctn), fully recognized as the most reliable test to detect MTC, is not universally accepted as routine test in all patients with thyroid nodule(s). The authors of this paper reappraise critically the matter of Ctn measurement in view of the recent advancements in the literature to point out the essential information to be known, and then to prepare an easy-to-use guide for clinicians to appropriately consider the measurement of serum Ctn during clinical practice.

Continuous subcutaneous rhPTH infusion for managing difficult chronic hypoparathyroidism. A systematic review.

PURPOSE: Standard treatment for chronic hypoparathyroidism is represented by long-life per os supplementation of calcium and vitamin D. Since 90s, exogenous PTH is also available, but a not negligible number of patients experience a poor control. Starting from the experience with pumps in diabetes, it has been hypothesized that the infusion of PTH through pump might result in a better disease control. The aim of this systematic review is to summarize the published data about continuous subcutaneous PTH infusion in chronic hypoPTH patients and achieve conclusions for clinical practice. METHODS: A comprehensive computer literature search of the PubMed/MEDLINE, Embase, and Scopus databases was conducted by two authors independently (last search on November 30, 2022). All findings were summarized and critically discussed. RESULTS: We included 14 of the 103 retrieved articles, 2 RCTs, 8 case reports, and 4 case series, published between 2008 and 2022. Of the total 40 patients, 17 were adults, and 23 pediatric. The etiology was postsurgical in 50% of cases and genetic in the other 50%. All had a failure of standard care and a rapid improvement of clinical and biochemical parameters on PTH pump therapy, without severe adverse events. CONCLUSIONS: Based on literature, pump PTH infusion may represent an effective, safe, and feasible option for patients with chronic hypoparathyroidism refractory to standard therapy. From a clinical perspective, careful patient selection, a skilled healthcare team, the assessment of the local setting and the collaboration with pump suppliers are essential.

Calcium Citrate Versus Calcium Carbonate in the Management of Chronic Hypoparathyroidism: A Randomized, Double-Blind, Crossover Clinical Trial.

In hypoparathyroidism (HypoPT), calcium supplementation is virtually always required, although the disease is likely to be associated with an increased risk of nephrolithiasis. The use of calcium citrate (Ca-Cit) theoretically could have a positive impact on the nephrolithiasis risk because citrate salts are used to reduce this risk. Our objective was to evaluate the potential therapeutic advantage of Ca-Cit in comparison with calcium carbonate (CaCO3 ) in HypoPT, on nephrolithiasis risk factors, as well as to their ability to maintain desirable serum calcium levels. We also evaluated these preparations on quality of life (QOL). This randomized, double-blind, crossover trial recruited 24 adults with postsurgical chronic hypoparathyroidism at Campus Bio-Medico University of Rome. Participants were randomized 1:1 to Ca-Cit or CaCO3 for 1 month and then crossed over to the other treatment for another month. The primary outcomes were changes in albumin-adjusted serum calcium and in ion activity product of calcium oxalate levels (AP[CaOx] index). Secondary efficacy outcomes included changes in SF-36 survey score, fatigue score, constipation, and adverse events. No difference in terms of AP(CaOx) index was observed between the two groups. However, Ca-Cit was associated with a significant reduction in the oxalate/creatinine ratio compared with CaCO3 (-2.46 mmol/mol [SD 11.93] versus 7.42 mmol/mol [SD 17.63], p = 0.029). Serum calcium and phosphorus concentration was not different between the two calcium preparations. Ca-Cit was associated with less constipation (p = 0.047). No difference was found in QOL scores. Although Ca-Cit did not modify the AP(CaOx) index when compared with CaCO3, it was associated with a reduction in urinary oxalate excretion that could have a potential beneficial effect on nephrolithiasis risk. These results are likely to have clinical implications in HypoPT, particularly those who do not tolerate CaCO3 and those affected by nephrolithiasis. A longer-term experience is needed to confirm these findings. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Proton Pump Inhibitors and Fractures in Adults: A Critical Appraisal and Review of the Literature.

Despite the large number of patients worldwide being on proton pump inhibitors (PPIs) for acid-related gastrointestinal disorders, uncertainty remains over their long-term safety. Particularly, the potential side effects of these drugs on bone health have been evaluated in the last years. The purpose of our narrative review is to gather and discuss results of clinical studies focusing on the interactions between PPIs and fracture risk. Data generated mainly from nested case-control studies and meta-analysis suggest that long-term/high-dose PPIs users are characterized by an increased risk of fragility fractures, mainly hip fractures. However, in these studies, the PPIs-induced bone impairment is often not adjusted for different confounding variables that could potentially affect bone health, and exposure to PPIs was reported using medical prescriptions without adherence evaluation. The mechanisms of the PPI-related bone damage are still unclear, but impaired micronutrients absorption, hypergastrinemia, and increased secretion of histamine may play a role. Clinicians should pay attention when prescribing PPIs to subjects with a preexistent high risk of fractures and consider antiosteoporotic drugs to manage this additive effect on the bone. However, further studies are needed to clarify PPIs action on the bone.

Calcium citrate: from biochemistry and physiology to clinical applications.

Adequate daily calcium intake should normally be achieved by dietary sources. Since low calcium diets are quite common in subjects that do not reach the recommended intake and particularly those at risk of fractures, calcium supplements may become necessary. Different forms of calcium salts are available, but products containing calcium citrate and calcium carbonate complexes are the most frequently used. Although only limited evidence on the efficacy and long-term safety of calcium citrate is available, these supplements may represent a valuable product for the management of different chronic pathological conditions. The aim of this review was to evaluate the current and potential clinical applications of calcium citrate. In particular, we focused on the use of calcium citrate supplementation in subjects with osteoporosis or in bariatric patients. Other pathological conditions that could benefit calcium citrate supplementation may include achloridria, chronic hypoparathyroidism and hypocitraturic subjects with moderate/high risk of nephrolithiasis. Indeed, citrate salts are widely used in the treatment of nephrolithiasis, since they have shown an inhibitory effect on kidney stone formation and recurrence.

Role of 18F-Choline Positron Emission Tomography/Computed Tomography to Detect Structural Relapse in High-Risk Differentiated Thyroid Cancer Patients.

BACKGROUND: This study aimed to evaluate the role of 18F-choline (18F-FCH) positron emission tomography (PET)/computed tomography (CT) in high-risk differentiated thyroid cancer (DTC) patients with suspected relapse. It also compared 18F-FCH-PET/CT results with those of fludeoxyglucose (18F-FDG)-PET/CT and evaluated the additional diagnostic value and clinical impact of the combined use of these two tracers. Finally, it assessed the association between the clinical, biochemical, and histological parameters and 18F-FCH-PET/CT and 18F-FDG-PET/CT results. METHODS: The study prospectively enrolled high-risk DTC patients treated with thyroidectomy and radioactive iodine therapy and presenting high/increasing thyroglobulin levels under thyrotropin suppression, negative/inconclusive neck ultrasound, and negative 131I whole-body scan. All patients underwent 18F-FDG-PET/CT and 18F-FCH-PET/CT within 30 days of each other. Experienced nuclear medicine physicians examined the images of both procedures, and an integrated analysis of the two PET/CT modalities was also conducted. For each modality, a patient-based analysis (PBA) and lesion-based-analysis (LBA) was performed. On PBA, sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were calculated. On LBA, only sensitivity was calculated. The standard of reference was based on clinical, imaging, and histological data. RESULTS: Twenty-five high-risk DTC patients were included; DTC relapse/persistence was confirmed in 23 patients. On PBA, 18F-FDG-PET/CT, 18F-FCH-PET/CT, and the integrated evaluation of the two imaging modalities showed the following rates: sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were 69.6%, 100%, 22.2%, 100%, and 72% versus 56.5%, 100%, 16.7%, 100%, and 60% versus 82.6%, 100%, 33.3%, 100%, and 84%, respectively. When compared with 18F-FDG-PET/CT, the integrated analysis of these two imaging procedures changed the clinical management in 4/23 (17%) patients. On LBA, the sensitivity rates of 18F-FDG-PET/CT, 18F-FCH-PET/CT, and the combined evaluation of the two modalities were 58.7%, 38.1%, and 66.7%, respectively; when only lymph node involvement was considered, the rates were 56.3%, 53.1%, and 68.8%, respectively. Serum thyroglobulin doubling time (Tg-DT) <12 months was significantly associated with positive 18F-FCH-PET/CT. A trend toward a significant association was also found between positive 18F-FDG-PET/CT and both Tg-DT <12 months and DTC aggressive subtypes. CONCLUSION: 18F-FCH-PET/CT may add important information during the follow-up of high-risk DTC patients. 18F-FCH-PET/CT may be considered a useful complementary tool in patients affected by non-aggressive DTC subtypes, with Tg-DT <12 months, high risk of lymph node spreading, and negative or doubtful 18F-FDG-PET/CT.

Liquid liothyronine to obtain target TSH in differentiated thyroid cancer patients.

In the last ten years a liquid formulation of liothyronine (L-T3) became available. To date, no studies on its systematic use have been reported. This study is aimed at assessing the reliability of liquid L-T3 in achieving target TSH in patients with differentiated thyroid cancers (DTC). Twenty-one high risk DTC patients in whom levothyroxine treatment up to 2.0 µg/kg/day did not suppress TSH levels (i.e. >0.1 mIU/L) were selected. Maintaining the same L-T4 dose, they started to assume liquid L-T3 at an initial fixed dose of 3.55 µg (5 drops). Further adjustments of L-T3 dose were tailored according to individual assessment. Initial serum TSH ranged from 0.8 to 12.0 mIU/L, when patients assumed high dose of L-T4 alone. Following the addition of a daily single dose of 3.55 µg L-T3, the target TSH was attained in five patients (23.8%). After increasing L-T3 dose up to a mean of 7.3±3.4 µg/day all patients reached target serum TSH (<0.1 mIU/L). The mean individual L-T3 dose was significantly correlated with the body weight and was 0.11±0.04 µg/kg/day (p=0.013). Mean L-T4:L-T3 ratio was 21:1. No patients showed skewed free-T3 or free-T4 values, neither experienced discomfort nor reported adverse events. Liquid L-T3 can be useful to achieve optimal TSH suppression in high risk DTC with not suppressed TSH on L-T4 alone. This formulation allows an individual tailoring of L-T3, minimizing risks of side effects as well as of overtreatment in these clinical conditions.