INTRODUCTION:Several physiological changes occur during the aging process, with perhaps the most apparent being modifications in body composition. The objective was to evaluate ongoing changes in body composition, throughout the aging process. MATERIALS AND METHODS:A cross-sectional study was conducted in 975 participants (612 women, 363 men) aged 18-89 years, whose body composition was assessed using dual-energy X-ray absorptiometry (DXA). RESULTS:The mean age was 48 ± 17 years for women and 43 ±15 years for men (p < 0.01). Men exhibited a greater amount of lean mass compared to women (54.5 ± 9.4 vs. 37.7 ± 5.5 kg; p<0.0001). Women showed a higher percentage of lower limb lean mass than men (78 vs. 74%; p < 0.05). Age was independently associated with decreased appendicular muscle mass, with a reduction of 0.38 kg per decade. On the other hand, women exhibited higher relative fat mass and a greater proportion of lean tissue in the lower limbs. Fat tissue increased with age in both sexes, remaining consistently higher in women. Lean mass and bone mineral content peaked in the second and third decades of life and declined thereafter. CONCLUSION:This study highlights the changes in body composition at various life stages, revealing a peak gain of lean tissue between the second and third decades, followed by a decline in subsequent years. To our knowledge, this is the first study that evaluates the changes in body composition in our country.

Purpose To describe changes in bone microarchitecture after 6 and 12 months of romosozumab (ROMO), identify responders based on cortical thickness (Ct.Th) increase at the distal radius (≥3% at 12 months), and explore factors associated with treatment response. Methods We conducted a prospective cohort study of postmenopausal women with osteoporosis at very high fracture risk who started ROMO between August 2021 and February 2023. HR-pQCT, BMD, and bone turnover markers were assessed at baseline, 6, and 12 months. Patients were classified as responders or non-responders based on 12-month Ct.Th changes. Results Sixteen patients were analyzed. Although improvements in distal tibial microarchitecture were observed at 12 months, treatment responses were heterogeneous. Nine patients were classified as responders and seven as non-responders. Baseline characteristics were similar, though responders had lower trabecular bone parameters at the distal radius. At 12 months, responders showed significant gains in Ct.Th and cortical area at both distal tibia (+5% and + 5%) and radius (+7% and + 6%), while non-responders showed no improvement or decline. These trends were evident by 6 months. Lumbar spine and hip BMD increased significantly only in responders (+14% and + 6%). PTH levels rose in both groups at 6 months but continued increasing only in non-responders, despite comparable vitamin D status. Conclusion By stratifying patients based on Ct.Th changes, we identified treatment responders (56%) with rapid cortical bone improvements detectable at 6 monthsIdentifying clinical predictors of ROMO responsiveness and determining whether shorter treatment durations may be justified in selected patients warrant further investigation.

To determine the frequency, type, and severity of acute-phase reaction (APR) following zoledronate (ZOL) infusion, identify associated clinical risk factors, and compare treatment-naïve patients with those receiving ZOL as sequential therapy. A secondary objective was to assess recall bias through a 90-day retest. A prospective study was conducted at a single bone clinic. Patients who received 5 mg ZOL were invited to complete questionnaires at 3 and 7 days post-infusion. Symptom frequency and severity were analyzed, and clinical factors were assessed using multivariate logistic regression. Symptoms with intensity ≥ 8 on a 0–10 Numerical Rating Scale (NRS) were considered severe. The mean age of the 1,150 patients was 66.9 ± 8.5 years, 97

Osteoporosis in men is an underdiagnosed condition, frequently associated with secondary causes, which are linked to greater clinical severity and fracture risk. We aimed to describe the clinical, densitometric, and biochemical characteristics of men aged ≥50 years with osteoporosis; to determine the frequency of secondary osteoporosis; and to compare bone mineral density and fracture prevalence between primary and secondary forms. Materials and methods: This retrospective cross-sectional study analyzed 183 medical records of men evaluated at IDIM between 2012 and 2021. Inclusion criteria were a T-score ≤−2.5 at the lumbar spine or femoral neck, or a fragility fracture. Clinical, densitometric, biochemical, and fracture variables were collected. Results: Mean age was 75.3±11.8 years and BMI 25.7±3.3 kg/m². A family history of osteoporosis was reported by 13% and parental hip fracture by 10%. DXA established the diagnosis in 75% of cases, with the hip most frequently affected (40%), followed by the lumbar spine (31%). Mean BMD was 0.830±0.20 g/cm² at the lumbar spine and 0.710±0.10 g/cm² at the femoral neck. Among 163 patients, 61% had vitamin D levels <30 ng/mL. Secondary osteoporosis was identified in 25% of cases, mainly associated with medications, hypogonadism, and hipercalciuria. These patients had lower femoral neck BMD (p=0.045) and higher fracture prevalence (74% vs. 41%; p=0.0002), particularly multiple vertebral fractures. Conclusions: Secondary osteoporosis in men presents greater clinical severity and higher fracture burden than primary osteoporosis, reinforcing the need for thorough etiological evaluation.

Radioiodine-refractory (RAIR) differentiated thyroid carcinoma (DTC), particularly those harboring BRAF V600E mutations, is associated with poor prognosis due to loss of iodine avidity. Pharmacologic MAPK pathway inhibition with BRAF inhibitors has emerged as a potential redifferentiation strategy to restore iodine uptake and enable further radioiodine (RAI) therapy. To describe clinical and imaging outcomes of redifferentiation therapy with short-term dabrafenib in patients with metastatic BRAF V600E–mutant papillary thyroid carcinoma (PTC). We retrospectively analyzed four consecutive patients with metastatic BRAF V600E–positive PTC and disease refractory to prior RAI therapy. All patients received dabrafenib 150 mg twice daily for 30 days, followed by RAI (100 mCi I-131) under TSH stimulation either by hormone withdrawal or recombinant human TSH. Pre- and post-treatment imaging and biochemical markers were assessed to evaluate iodine uptake and treatment response. Three of the four patients exhibited new or increased iodine uptake in metastatic lung or nodal sites after dabrafenib therapy. Structural or biochemical responses were observed in two patients: one showed partial response and TgAb decline; the other achieved disease stabilization with biochemical stability. One of these patients, who had previously achieved a complete response after lenvatinib but developed severe adverse events, successfully underwent redifferentiation with stabilization of disease. In contrast, one patient showed no iodine uptake or response. No significant toxicities related to dabrafenib were reported. Short-term BRAF inhibition with dabrafenib enabled redifferentiation and restored RAI avidity in a subset of patients with BRAF V600E–mutant metastatic PTC, with clinical benefit. This approach may be particularly useful in patients ineligible for multikinase inhibitors or as a bridge to re-treatment with I-131. Further prospective studies are warranted to identify predictors of response and to optimize timing, duration, and sequencing of redifferentiation strategies.

Tumor-induced osteomalacia (TIO) is a rare disorder characterized by impaired bone mineralization due to phosphate wasting. Long-term changes in BMD and microarchitecture after surgical cure or medical therapy in TIO are not well understood. This study describes changes in BMD, microarchitecture, and bone strength in patients with TIO following surgical cure or medical therapy. A prospective cohort study included adults diagnosed with TIO from May 2018 to 2024, categorized into those with surgical cure and those on medical therapy. Follow-up assessments were classified as early (median 8 mo), intermediate (median 17 mo), and long-term (median 26 mo). Fifteen patients were included: seven achieved surgical cure, and eight remained on medical therapy. Lumbar spine BMD increased by +19% at early, +27% at intermediate, and +15% at long-term follow-up. Total hip BMD increased by +31%, +36%, and +31% at early, intermediate, and long-term assessments, respectively. All patients achieved a normal lumbar spine BMD, while 91% attained a normal total hip BMD. At the distal tibia, substantial increases in bone microarchitecture parameters-cortical area (Ct.Ar), cortical volumetric density (Ct.vBMD), and cortical thickness (Ct.Th)-were observed. Notably, Ct.Th improved to levels comparable to healthy controls. Bone strength improved by 13% but was not statistically significant, probably due to the small sample size. At the distal radius, most parameters remained stable. Patients with surgical cure showed more rapid and substantial improvements in BMD and cortical microarchitecture than non-cured patients, but these differences did not reach statistical significance. Overall, bone recovery in TIO is gradual, with gains in spine and hip BMD and significant improvements in tibial cortical parameters. However, some aspects of bone microarchitecture remained below control levels, underscoring the need for ongoing monitoring and individualized management strategies.

Purpose To evaluate objective response rates (ORR), progression-free survival (PFS), and overall survival (OS) associated with tyrosine kinase inhibitors (TKIs) in patients with radioiodine refractory differentiated thyroid cancer (RR-DTC). Additionally, to compare: i) ORR and PFS among patients treated with lenvatinib and sorafenib; ii) ORR and PFS among patients receiving lenvatinib as first-line vs. second-line and; iii) adverse effects (AEs) observed in patients treated with these medications. Methods Retrospective analysis of RR-DTC adult patients treated with TKIs at the Division of Endocrinology, University of Buenos Aires (March 2011-November 2023). Results Among 43 patients included in the study, 32 received sorafenib (30 as first-line and 2 as second-line), while 29 received lenvatinib (12 as first-line and 17 as second-line). The median PFS and OS for the entire cohort were 32.7 and 39.0 months, respectively. Lenvatinib demonstrated a significantly higher ORR compared to sorafenib (37.9% vs. 9.4%, p = 0.008). However, both drugs exhibited similar median PFS (23.2 vs. 16.0 months, p = 0.419). No significant difference was observed in ORR and PFS between patients receiving first-line vs. second-line lenvatinib. Sorafenib-treated patients experienced higher rates of hand-foot skin syndrome (69% vs. 41%, p = 0.032) and alopecia (25% vs. 3%, p = 0.018), whereas lenvatinib-treated patients had higher rates of proteinuria (31% vs. 0%, p < 0.001) and grade 3 hypertension (31% vs. 9%, p = 0.034). Conclusion TKIs demonstrated efficacy and tolerability comparable to real-world data in RR-DTC. PFS was not statistically different between sorafenib and lenvatinib. Our study will help guide physicians in making informed decisions regarding treatment sequencing with TKIs in these patients.

Purpose: Toassessthefrequencyofdysmobility syndrome (DS) in a group of postmenopausal women, to determine the frequency of fragility fractures in these patients, and to compare the frequency of fragility fractures and other clinical, biochemical, densitometric, and muscle health characteristics between patients with and without DS. Methods: Postmenopausal women aged >= 60 years were invited to participate in a muscle health study program in our bone clinic. The diagnosis of DS was considered when at least three of the following factors were present: osteoporosis, >= 1 fall in the preceding year, low muscle mass, slow gait speed, low grip strength, and high-fat mass. The cohort was divided into patients with DS and without DS. Results: The mean age in the study cohort (n = 250) was 70.36 +/- 7.72 years. DS was diagnosed in 77 patients (30.8 %). A history of falls in the preceding year and the prevalence of fragility fractures were more frequent in patients with DS in comparison with the control group (60% vs. 19%, p <0.001 and 42% vs 17%, p <0.001, respectively). Furthermore, the history of fragility fractures was significantly associated with the presence of DS (OR 4.92, 95% CI 2.3-10.4, p <0.001). Discussion: A significant association was found between DS and a history of fragility fractures. Although this new concept needs further investigation, it seems that the identification of various compartments affected by the aging process results in an opportunity to better predict major adverse events in the elderly.

Data on long-term treatment regimens for preventing bone mineral density (BMD) loss that occurs after denosumab (Dmab) withdrawal are scarce. Our aim was to evaluate the long-term changes (12-36 months) in BMD and bone turnover markers in a group of postmenopausal women who had been treated with Dmab and received subsequent treatment with bisphosphonates. Secondary objectives were to evaluate factors associated with BMD loss, to compare the BMD change in patients who received oral vs intravenous bisphosphonates, and to assess the frequency of fragility fractures after Dmab discontinuation. The clinical data of 54 patients, 26 of whom had clinical and DXA assessments at 36 months, were analyzed. After 12 months, the mean LS BMD had decreased by 2.8% (+/- 5.0), FN BMD by 1.9% (+/- 5.8), and TH BMD by 1.9% (+/- 3.7). After 36 months, LS BMD had decreased by 3.7% (+/- 6.7), FN BMD by 2.5% (+/- 7.1), and TH BMD by 3.6% (+/- 5.2). C-terminal cross-linked telopeptide of type I collagen significantly increased during the first 12 months after Dmab withdrawal but then decreased at 36 months. BMD loss at 12 months was higher in patients with more than 30 months of Dmab treatment, but this difference was only statistically significant at FN (-3.3% vs -0.3%, P = .252 at LS, -3.3% vs 0.3%, P = .033 at FN, and -2.1% vs 0.9, P = .091 at TH). There were no statistically significant differences regarding the change in BMD at 12 and 36 months between oral and intravenous treatment. Seven patients suffered incidental vertebral fractures (clinical vertebral fractures: n = 6, morphometric fractures: n = 1) three of which were multiple. None of these patients were treated following international or institutional guidelines or recommendations. In summary, our study suggests that bisphosphonates can help maintain BMD for 36 months after Dmab discontinuation. In our real-life study, we examined 54 patients who received bisphosphonate treatment after stopping denosumab. Among them, 26 patients underwent long-term assessments. We found that after three years of sequential treatment with bisphosphonates, bone density loss was less than 4%, with most of the loss occurring within the first 12 months. This suggests that bisphosphonates can help maintain bone density in patients who discontinue denosumab.

Anaplastic thyroid cancer (ATC) is an infrequent thyroid tumor that usually occurs in elderly patients. There is often a history of previous differentiated thyroid cancer suggesting a biological progression. It is clinically characterized by a locally invasive cervical mass of rapid onset. Metastases are found at diagnosis in 50% of patients. Due to its adverse prognosis, a prompt diagnosis is crucial. In patients with unresectable or metastatic disease, multimodal therapy (chemotherapy and external beam radiotherapy) has yielded poor outcomes with 12-month overall survival of less than 20%. Recently, significant progress has been made in understanding the oncogenic pathways of ATC, leading to the identification of BRAF V600E mutations as the driver oncogene in nearly 40% of cases. The combination of the BRAF inhibitor dabrafenib (D) and MEK inhibitor trametinib (T) showed outstanding response rates in BRAF-mutated ATC and is now considered the standard of care in this setting. Recently, it was shown that neoadjuvant use of DT followed by surgery achieved 24-month overall survival rates of 80%. Although these approaches have changed the management of ATC, effective therapies are still needed for patients with BRAF wild-type ATC, and high-quality evidence is lacking for most aspects of this neoplasia. Additionally, in real-world settings, timely access to multidisciplinary care, molecular testing, and targeted therapies continues to be a challenge. Health policies are warranted to ensure specialized treatment for ATC.The expanding knowledge of ATC´s molecular biology, in addition to the ongoing clinical trials provides hope for the development of further therapeutic options.