Global guidance for the recognition, diagnosis, and management of tumor-induced osteomalacia.

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by mesenchymal tumors that secrete fibroblast growth factor 23 (FGF23). Patients present with progressive bone pain, muscle weakness, and fragility fractures. TIO is characterized by hypophosphatemia, excess renal phosphate excretion, and low/inappropriately normal 1,25-dihydroxyvitamin D (1,25(OH)2 D) levels. Rarity and enigmatic clinical presentation of TIO contribute to limited awareness among the medical community. Accordingly, appropriate diagnostic tests may not be requested, leading to delayed diagnosis and poorer patient outcomes. We have developed a global guidance document to improve the knowledge of TIO in the medical community, enabling the recognition of patients with TIO and appropriate referral. We provide recommendations aiding diagnosis, referral, and treatment, helping promote a global standard of patient management. We reviewed the literature and conducted a three-round Delphi survey of TIO experts. Statements were drafted based on published evidence and expert opinions (≥70% consensus required for final recommendations). Serum phosphate should be measured in patients presenting with chronic muscle pain or weakness, fragility fractures, or bone pain. Physical examination should establish features of myopathy and identify masses that could be causative tumors. Priority laboratory evaluations should include urine/serum phosphate and creatinine to assess renal tubular reabsorption of phosphate and TmP/GFR, alkaline phosphatase, parathyroid hormone, 25-hydroxyvitamin D, 1,25(OH)2 D, and FGF23. Patients with the clinical/biochemical suspicion of TIO should be referred to a specialist for diagnosis confirmation, and functional imaging should be used to localize causative tumor(s). Recommended treatment is tumor resection or, with unresectable/unidentifiable tumors, phosphate salts plus active vitamin D, or burosumab.

[A search for secondary causes of osteoporosis or low mineral density in postmenopausal women]. / Osteoporosis postmenopáusica: relevancia de la búsqueda estructurada de causas secundarias.

BACKGROUND: A secondary cause can be found in up to one third of women with osteoporosis, potentially modifying their therapeutic approach. AIM: To determine the prevalence of secondary causes and risk factors for decreased bone mineral density (BMD) and osteoporosis. MATERIAL AND METHODS: We included postmenopausal women with a diagnosis of osteoporosis or low BMD who consulted for the first time in an endocrinology clinic between October 2018 and March 2020. A complete medical history, physical examination and a standardized laboratory assessment to identify secondary causes were performed. RESULTS: During the study period, 114 women were evaluated, 30 of them with low BMD and 84 with osteoporosis. After obtaining a medical history and a structured laboratory screening, at least one secondary cause was found in 50% of patients with osteoporosis and in 67% of those with low BMD. Most patients with no identified secondary cause had at least one risk factor for fragility fractures. CONCLUSIONS: A structured evaluation that includes medical history and standardized laboratory study in postmenopausal women with osteoporosis or low BMD, is a valuable tool to identify secondary causes of osteoporosis.

[Clinical features of Chilean patients with Fibrous Dysplasia/McCune-Albright Syndrome]. / Caracterización clínica de pacientes chilenos con displasia fibrosa/síndrome de McCune-Albright.

BACKGROUND: Fibrous Dysplasia/McCune-Albright Syndrome (FD/MAS) is characterized by a spectrum of manifestations that may include fibrous dysplasia of bone and multiple endocrinopathies. AIM: To describe the clinical spectrum, the study and follow-up of patients with FD/MAS cared at our institution. MATERIAL AND METHODS: Review of medical records of 12 pediatric and adult patients (11 women) who met the clinical and genetic diagnostic criteria for FD/ MAS. RESULTS: The patients' mean age at diagnosis was 4.9 ± 5.5 years. The most common initial clinical manifestation was peripheral precocious puberty (PPP) in 67% of patients and 75% had café-au-lait spots. Fibrous dysplasia was present in 75% of patients and the mean age at diagnosis was 7.9 ± 4.7 years. Ten patients had a bone scintigraphy, with an age at the first examination that varied between 2 and 38 years of age. The most frequent location of dysplasia was craniofacial and appendicular. No patient had a recorded history of cholestasis, hepatitis, or pancreatitis. In four patients, a genetic study was performed that was positive for the pathogenic variant of guanine nucleotide binding protein, alpha stimulating (GNAS). CONCLUSIONS: These patients demonstrate the variable nature of the clinical presentation and study of FD/MAS. It is essential to increase the index of diagnostic suspicion and adherence to international recommendations.

Characterization of Oral Health Status in Chilean Patients with X-Linked Hypophosphatemia.

X-Linked Hypophosphatemia (XLH) is the most common cause of inherited hypophosphatemic rickets. Dental involvement, including spontaneous abscesses and/or fistulae, is an important part of the disease and has not been completely defined, especially in cohorts from developing countries. To describe oral health status in a cohort of Chilean patients with XLH and explore its correlation with biochemical presentation and treatment, we conducted a cross-sectional observational study of patients with PHEX mutation-confirmed XLH. All patients had an oral clinical exam, radiographic evaluation; clinical and biochemical data were obtained to determine their association with oral features. Twenty-six patients were included, 77% adults and 23% children. Most adults (89%) had past or current dental pulp pathology (abscesses and/or fistulae). Pulpal chamber enlargement and radiolucent apical lesions were common radiological features (94 and 74%, respectively). In children, abscess and/or fistulae were also common (33%). Caries index, which was determined by dmft/DMFT, was higher than the Chilean national average. Early and long-term therapy with phosphate and activated vitamin D was associated with lower carious index and attachment loss. XLH patients frequently present with high pulpal involvement and carious index. Conventional therapy was associated with lower carious index and attachment loss. These data highlight the importance of early and periodical dental care in order to prevent dental damage and assure a good quality of oral health for XLH patients.

Tumor-Induced Osteomalacia.

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by tumoral production of fibroblast growth factor 23 (FGF23). The hallmark biochemical features include hypophosphatemia due to renal phosphate wasting, inappropriately normal or frankly low 1,25-dihydroxy-vitamin D, and inappropriately normal or elevated FGF23. TIO is caused by typically small, slow growing, benign phosphaturic mesenchymal tumors (PMTs) that are located almost anywhere in the body from the skull to the feet, in soft tissue or bone. The recent identification of fusion genes in a significant subset of PMTs has provided important insights into PMT tumorigenesis. Although management of this disease may seem straightforward, considering that complete resection of the tumor leads to its cure, locating these often-tiny tumors is frequently a challenge. For this purpose, a stepwise, systematic approach is required. It starts with thorough medical history and physical examination, followed by functional imaging, and confirmation of identified lesions by anatomical imaging. If the tumor resection is not possible, medical therapy with phosphate and active vitamin D is indicated. Novel therapeutic approaches include image-guided tumor ablation and medical treatment with the anti-FGF23 antibody burosumab or the pan-FGFR tyrosine kinase inhibitor, BGJ398/infigratinib. Great progress has been made in the diagnosis and treatment of TIO, and more is likely to come, turning this challenging, debilitating disease into a gratifying cure for patients and their providers.

Nephropathic Cystinosis: A Distinct Form of CKD-Mineral and Bone Disorder that Provides Novel Insights into the Regulation of FGF23.

BACKGROUND: The rare lysosomal storage disease nephropathic cystinosis presents with renal Fanconi syndrome that evolves in time to CKD. Although biochemical abnormalities in common causes of CKD-mineral and bone disorder have been defined, it is unknown if persistent phosphate wasting in nephropathic cystinosis is associated with a biochemical mineral pattern distinct from that typically observed in CKD-mineral and bone disorder. METHODS: We assessed and compared determinants of mineral homeostasis in patients with nephropathic cystinosis across the predialysis CKD spectrum to these determinants in age- and CKD stage-matched patients, with causes of CKD other than nephropathic cystinosis. RESULTS: The study included 50 patients with nephropathic cystinosis-related CDK and 97 with CKD from other causes. All major aspects of mineral homeostasis were differentially effected in patients with CKD stemming from nephropathic cystinosis versus other causes. Patients with nephropathic cystinosis had significantly lower percent tubular reabsorption of phosphate and fibroblast growth factor-23 (FGF23) at all CKD stages, and lower blood phosphate in CKD stages 3-5. Linear regression analyses demonstrated lower FGF23 levels in nephropathic cystinosis participants at all CKD stages when corrected for eGFR and age, but not when adjusted for serum phosphate. CONCLUSIONS: Nephropathic cystinosis CKD patients have mineral abnormalities that are distinct from those in CKD stemming from other causes. Persistently increased urinary phosphate excretion maintains serum phosphate levels within the normal range, thus protecting patients with nephropathic cystinosis from elevations of FGF23 during early CKD stages. These findings support the notion that phosphate is a significant driver of increased FGF23 levels in CKD and that mineral abnormalities associated with CKD are likely to vary depending on the underlying renal disease.

[An update on parathyroid carcinoma]. / Puesta al día: carcinoma paratiroideo.

Parathyroid carcinoma is a rare malignant disease that presents as a sporadic or familial primary hyperparathyroidism (PHP). The latter is associated with some genetic syndromes. It occurs with equal frequency in both sexes, unlike PHP caused by parathyroid adenoma that is more common in women. It should be suspected in cases of severe hypercalcemia, with high parathyroid hormone levels and a palpable cervical mass. Given the difficulty in distinguishing between parathyroid carcinoma and adenoma prior to the surgery, the diagnosis is often made after parathyroidectomy. The only curative treatment is complete surgical resection with oncologic block resection of the primary tumor to ensure free margins. Adjuvant therapies with chemotherapy or radiation therapy do not modify overall or disease-free survival. Recurrences are common and re-operation of resectable recurrent disease is recommended. The palliative treatment of symptomatic hypercalcemia is crucial in persistent or recurrent disease after surgery since morbidity and mortality are more associated with hypercalcemia than with tumor burden.

[Hypophosphatemia induced by carboxymaltose iron and imatinib. Report of two cases]. / Hipofosfatemia inducida por drogas: fierro carboximaltosa e imatinib. Casos clínicos.

Hypophosphatemia is a relatively frequent and a potentially serious adverse drug effect. Clinically it is characterized by bone pain and muscle weakness. There are several mechanisms by which a drug can induce hypophosphatemia and they can be classified according to whether or not they are mediated by an excess of Fibroblast Growth Factor 23 (FGF23). We report two patients with the condition: (i) A 49-year-old woman with Chronic Myeloid Leukemia (CML) and gastric sleeve surgery at 46 years of age. After receiving intravenous carboxymaltose iron in one occasion due to refractory anemia, she developed symptomatic hypophosphatemia. Urinary phosphate losses associated with high FGF23 levels were confirmed. Plasma phosphate returned to normal values 90 days after the iron administration. (ii) A 40-year-old man with a history of CML in whom imatinib was started. He developed symptomatic hypophosphatemia due to non FGF23-mediated hyperphosphaturia. As treatment with imatinib could not be interrupted, hypophosphatemia and its symptoms resolved with oral phosphate intake. These cases illustrate the importance of recognizing and treating drug-induced hypophosphatemia in a timely manner, and thus avoid the morbidity associated with this entity.

[Pseudohypoparathyroidism: report of two cases of late presentation]. / Pseudohipoparatiroidismo de presentación tardía: reporte de dos casos.

Pseudohypoparathyroidism (PHP) is a group of rare genetic disorders that share organ targeted resistance to the action of parathyroid hormone (PTH) as a common feature. Biochemically, they may present with hypocalcemia, hyperphosphatemia and elevated PTH. Some forms present with a specific phenotype: short stature, round facies, short neck, obesity, brachydactyly and subcutaneous calcifications, called Albrigth's Hereditary Osteodystrophy (AHO). This spectrum of disorders are caused by several alterations in the gene coding for the alpha subunit of the G protein (GNAS): an ubiquitous signaling protein that mediates the action of numerous hormones such as PTH, TSH, gonadotropins, and ACTH, among others. According to their inheritance with maternal or paternal imprinting, they may manifest in a diversity of clinical forms. Although most commonly diagnosed during childhood, PHP may manifest clinically during adolescence or early adulthood. We report two late presenting cases of pseudohypoparathyroidism. A 21-year-old female with biochemical abnormalities characteristic of pseudohypoparathyroidism who was misdiagnosed as epilepsy and a 13-year-old boy with the classic AHO phenotype but without alterations in phospho-calcium metabolism, compatible with pseudopseudohypoparathyrodism.

[Guidelines of the Chilean Endocrinology Society for the correct clinical use of bone densitometry]. / Recomendaciones para el uso correcto de densitometría ósea en la práctica clínica. Consenso de la Sociedad Chilena de Endocrinología y Diabetes.

Osteoporosis is a silent and frequent disease, which increases fracture risk. Approximately half of women and one of five men over 50 years old will suffer an osteoporotic fracture throughout their lives. Dual-energy x-ray absorptiometry (DXA) allows a real bone mineral density (BMD) measurement in different parts of the skeleton and is considered the "gold standard" for quantifying osteoporosis with high accuracy and precision. The Board of the Chilean Society of Endocrinology and Diabetes (SOCHED) required from the Bone Disease Study Group to develop a consensus about the "Correct use of bone densitometry in clinical practice in Chilean population". Therefore, we elaborated 25 questions which addressed key aspects about the indications for a DXA scan, and the details of how to perform and report this test. Since some of the evidence obtained was of low quality or inconclusive, we decided to create a multidisciplinary group of national experts in osteoporosis to develop a consensus in this subject. The group consisted of 22 physicians including endocrinologists, gynecologists, geriatricians, radiologists, rheumatologists and nuclear medicine specialists. Using the Delphi methodology to analyze previously agreed questions, we elaborated statements that were evaluated by the experts who expressed their degree of agreement. The final report of this consensus was approved by the SOCHED board.

[Bone involvement in systemic mastocytosis: Report of two cases]. / Compromiso óseo en mastocitosis sistémica: una asociación frecuente, pero muchas veces inadvertida.

Systemic mastocytosis (SM) is characterized by pathologic expansion and activation of mast cells. The main clinical manifestations of SM include skin involvement, gastrointestinal symptoms and anaphylaxis due to the release of its mediators. Thirty percent of pat ients with SM have a low bone mass and 20% fractures. At the same time, SM affects 10% of male patients with idiopathic osteoporosis. Measuring serum tryptase is essential for the screening of MS. We report two cases of SM with bone involvement. A 25-year- old woman with prior diagnosis of SM, based on skin involvement, flushing, high serum tryptase and compatible bone marrow (BM) biopsy and genetic study. Low bone mass was diagnosed and treatment was started with calcium and vitamin D plus oral bisphosphona tes with adequate response. A 47 years old man who presented with multiple osteoporotic vertebral fractures and low bone mass. Treatment with vitamin D and alendronate was started, but the patient developed new vertebral fractures. The study was extended w ith measurement of serum tryptase that was elevated. Diagnosis of SM was confirmed with BM biopsy and the patient was referred to hematology for specific care. These cases emphasize the importance of bone assessment in SM, as well as the need to rule out S M in patients with osteoporosis and no evident cause.

[Vitamin D and parathyroid hormone levels and bone mineral density in patients undergoing hematopoietic cell transplantation]. / Salud ósea en pacientes sometidos a trasplante de precursores hematopoyéticos: un nuevo problema a considerar.

BACKGROUND: Patients undergoing hematopoietic cell transplantation (HCT) are at increased risk of developing osteoporosis. AIM: To determine the frequency and severity of Vitamin D deficiency, secondary hyperparathyroidism and low bone mass in patients undergoing HCT. PATIENTS AND METHODS: Analysis of the database of patients undergoing HCT in our institution in the 2010-2015 period. We searched for patients with measurements of 25-OH vitamin D (25OHD), parathyroid hormone (PTH) and bone densitometry by double beam X ray absorptiometry (DXA) prior and up to one year after HCT. RESULTS: Ninety patients were included, 53 were evaluated prior to HCT and 37 after HCT. They represent 73% of all patients undergoing HCT in the period. Median 25OHD was 12 ng/ml (range 4-41.4). Ninety seven percent of patients had levels considered insufficient and 85% compatible with deficiency. Median PTH was 60.5 pg/ml (range 21-186). Forty five percent of patients had secondary hyperparathyroidism. DXA was performed in 65 patients (prior to HCT in 54 and after HCT in 11). Of these, 11% had had a low bone mineral density. CONCLUSIONS: Patients undergoing HCT have a high risk of vitamin D deficiency, secondary hyperparathyroidism and low bone mineral density.

[Constrictive pericarditis as a serious and rare presentation of systemic lupus erythematosus: Report of one case]. / Pericarditis constrictiva como presentación grave e infrecuente de lupus eritematoso sistémico: reporte de un caso y revisión de la literatura.

Constrictive Pericarditis (CP) is an unusual disease. Its most common causes are idiopathic or secondary to cardiac surgery. Less frequently it is caused by connective tissue diseases. We report a 30 years old woman hospitalized due to progressive dyspnea, chest pain and signs of right sided heart failure. During her stay, a Systemic Lupus Erythematosus (SLE) was diagnosed. The echocardiogram suggested a CP and the diagnosis was confirmed by cardiac catheterization. Pericardiectomy was successfully performed. The biopsy confirmed a nonspecific chronic pericarditis, with extensive fibrosis and absence of caseating granulomas. The patient had a satisfactory recovery.

Impaired Quality of Life in Patients with Post-Surgical Hypoparathyroidism.

BACKGROUND: Hypoparathyroidism is characterized by chronic hypocalcemia with low or abnormal parathyroid hormone levels. Thyroid surgery remains a predominant cause of hypoparathyroidism, often preventable by partial thyroidectomy. Although hypoparathyroidism can impair quality of life (QOL), data remain limited for Latin America. We aimed to characterize clinical manifestations and QOL in patients with postsurgical hypoparathyroidism. METHODS: This case-control study included patients (>18 years) who underwent total thyroidectomy (TT) for differentiated thyroid cancer (DTC) with postsurgical hypoparathyroidism (Group 1, Cases) and those with DTC who underwent TT without postsurgical hypoparathyroidism (Group 2, Controls). Clinical records were collected, and the SF-36v2 QOL survey and a structured symptom survey were applied. A logistic multivariate regression analysis was performed. RESULTS: This study included 106 subjects (Group 1, N=41; Group 2, N=65). Group 1 patients were younger, had a higher frequency of lymph node resection, and more frequently received Ι-131 than Group 2 patients (p<0.05). In the SF-36v2 survey, Group 1 had fewer physical-functioning scores (odds ratio, 3.8; 95% confidence interval, 1.2-11.7) and lower scores in mental and physical components than Group 2 and national records. Commonly reported symptoms include paresthesia, daily fatigue, and memory alterations. Treatment adherence rates were 56% and 71% for calcium and calcitriol, respectively. Furthermore, 24% of patients experienced one or more hypoparathyroidism drug-related adverse effects. CONCLUSIONS: Patients with postsurgical hypoparathyroidism had an impaired QOL, a high frequency of disease-associated symptoms, and limited treatment adherence. These results should be considered when deciding the best surgical alternative for DTC.

Nephrocalcinosis and kidney function in children and adults with X-linked hypophosphatemia: baseline results from a large longitudinal study.

BACKGROUND: In patients with X-linked hypophosphatemia (XLH), conventional therapy with oral phosphate salts and active vitamin D has been associated with nephrocalcinosis. However, the nature of the relationships among XLH, its treatment, nephrocalcinosis, and kidney function remain poorly understood. METHODS: Renal ultrasounds were performed and glomerular filtration rates were estimated (eGFR) at baseline in burosumab-naïve patients with XLH who participated in burosumab clinical trials (NCT02181764, NCT02526160, NCT02537431, NCT02163577, NCT02750618, NCT02915705) or enrolled in the XLH Disease Monitoring Program (XLH-DMP; NCT03651505). In this cross-sectional analysis, patient, disease, and treatment characteristics were described among patients with and without nephrocalcinosis. RESULTS: The analysis included 196 children (mean [SD] age 7.6 [4.0] yr) and 318 adults (40.3 [13.1] yr). Mean (SD) height z-score was -1.9 (1.2) for children and -2.3 (1.7) for adults. Nearly all children (97%) and adults (94%) had previously received conventional therapy. Nephrocalcinosis was detected in 22% of children and 38% of adults. In children, reduced eGFR <90 mL/min/1.73 m2 was more prevalent in those with nephrocalcinosis (25%) than in those without (11%), a finding that was not observed in adults. Children with nephrocalcinosis had lower mean values of TmP/GFR (p<.05), serum 1,25(OH)2D (p<.05), and eGFR (p<.001) and higher mean serum calcium concentrations (p<.05) than did those without nephrocalcinosis. Adults with nephrocalcinosis had lower mean serum phosphorus (p<.01) and 1,25(OH)2D (p<.05) concentrations than those without. Exploratory logistic regression analyses revealed no significant associations between the presence of nephrocalcinosis and other described patient or disease characteristics. CONCLUSIONS: Nephrocalcinosis was observed in nearly one-quarter of children and more than one-third of adults with XLH. Further study is needed to better understand the predictors and long-term consequences of nephrocalcinosis, with surveillance for nephrocalcinosis remaining important in the management of XLH.

Conventionally, patients with X-linked hypophosphatemia (XLH) were treated with phosphate and vitamin D taken by mouth. However, this therapy might lead to a buildup of calcium in the kidney, called nephrocalcinosis. Here, we tried to better understand how XLH, conventional therapy, nephrocalcinosis, and kidney function are related. Nephrocalcinosis was detected with kidney ultrasounds. Kidney function, called the estimated glomerular filtration rate (eGFR), was determined using blood levels of creatinine. Patients had been part of burosumab clinical trials or part of the XLH Disease Monitoring Program. Data were collected from patients before they received burosumab. The study included 196 children and 318 adults. Almost all children and adults had received conventional therapy. 22% of children and 38% of adults had nephrocalcinosis. Some lab values were different among patients with vs without nephrocalcinosis. Children with nephrocalcinosis had significantly greater loss of phosphate by the kidneys, lower blood levels of the active form of vitamin D (1,25(OH)2D), lower eGFR, and higher blood levels of calcium than those without nephrocalcinosis. Adults with nephrocalcinosis had significantly lower blood levels of phosphorus and 1,25(OH)2D concentrations than those without. It remains important to monitor patients with XLH for nephrocalcinosis. Further study is needed to better understand nephrocalcinosis.

Anticipated effects of burosumab treatment on long-term clinical sequelae in XLH: expert perspectives.

X-linked hypophosphatemia (XLH) is a rare, progressive, genetic disease with multisystem impact that typically begins to manifest in early childhood. Two treatment options exist: oral phosphate in combination with active vitamin D ("conventional therapy") and a fully human monoclonal anti-FGF23 antibody, burosumab. The clinical benefit of conventional therapy in adults is limited, and poor tolerance and complications are common. Burosumab was first approved as a treatment for XLH in 2018 and its disease-modifying benefits in clinical trials in children suggest burosumab treatment could also alter the disease course in adults. Without long-term clinical data on multiple XLH-related sequelae available, the results of an elicitation exercise are reported, in which eight global experts in XLH posited how long-term treatment with burosumab is anticipated to impact the life course of clinical sequelae in adults with XLH. Based on their clinical experiences, the available evidence and their disease understanding, the experts agreed that some long-term benefits of using burosumab are likely in adults with XLH even if they have a misaligned skeleton from childhood. Burosumab treatment is anticipated to reduce the incidence of fractures and halt the progression of clinical sequelae associated with conventional therapy. While the trajectories for established dental abscesses are not expected to improve with burosumab treatment, dental abscess development may be prevented. Starting treatment with burosumab in childhood to increase the likelihood of an aligned skeleton and continuation into and throughout adulthood to maintain euphosphatemia may optimize patient outcomes, although future real-world investigation is required to support this hypothesis.

[A clinical teaching course for residents improves self-perception about preparation to teach]. / Un curso de docencia clínica para residentes mejora la autopercepción de preparación para enseñar.

BACKGROUND: Medical doctors need to be competent to teach patients, their families, students, and the health care team. In a previous study we determined that although the residents attach great importance to have teaching skills, they do not feel prepared to meet this role. AIM: To assess self-perception of learning in a formal course of training how to teach for residents. MATERIAL AND METHODS: In 2004 we implemented the course "Residents as Clinical Teachers", based on the Stanford Faculty Development Center for Medical Teachers Model (SFDC), for residents of a Medical School. Residents of all the post graduate programs were invited to take the course as an elective during the period 2004-2011. At the end of the course each resident completed the pre/post Seminar Series Housestaff/student Questionnaire; assessing perceptions of learning, expressed in a Likert scale from 1-5. RESULTS: The implementation of the course in 111 residents significantly improved self-perception of general preparation for teaching and improved self-perception of preparedness in each educational category. The personal goals most commonly established by participants were on feedback (52,2%), control of session (44%) and communication of goals (40%). Barriers for teaching most frequently identified were lack of time to do clinical teaching (51,3%) and environmental limitations (16,2%). The main impact of the course reported by residents were acquisition of teaching skills or tools for teaching (39,6%), enhancing of motivation (14%), and a richer understanding of teaching principles (14%). CONCLUSIONS: A clinical teaching course for residents improves their self-perception of preparation to teach and enhances motivation for clinical teaching.

An Expert Perspective on Phosphate Dysregulation With a Focus on Chronic Hypophosphatemia.

Because of their rarity, diseases characterized by chronic hypophosphatemia can be underrecognized and suboptimally managed, resulting in poor clinical outcomes. Moreover, serum phosphate may not be measured routinely in primary care practice. Authors participated in several working sessions to advance the understanding of phosphate homeostasis and the causes, consequences, and clinical implications of chronic hypophosphatemia. Phosphate levels are regulated from birth to adulthood. Dysregulation of phosphate homeostasis can result in hypophosphatemia, which becomes chronic if phosphate levels cannot be normalized. Chronic hypophosphatemia may be underrecognized as serum phosphate measurement is not always part of routine analysis in the primary care setting and results might be misinterpreted, for instance, due to age-specific differences not being accounted for and circadian variations. Clinical consequences of chronic hypophosphatemia involve disordered endocrine regulation, affect multiple organ systems, and vary depending on patient age and the underlying disorder. Signs and symptoms of chronic hypophosphatemic diseases that manifest during childhood or adolescence persist into adulthood if the disease is inadequately managed, resulting in an accumulation of clinical deficits and a progressive, debilitating impact on quality of life. Early identification and diagnosis of patients with chronic hypophosphatemia is crucial, and clinical management should be started as soon as possible to maximize the likelihood of improving health outcomes. Furthermore, in the absence of a universally accepted description for "chronic hypophosphatemia," a definition is proposed here that aims to raise awareness of these diseases, facilitate diagnosis, and guide optimal phosphate management strategies by improving monitoring and assessment of patient response to treatment. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).