ABSTRACT Objective: This study aimed to investigate the association between 25OHD (total, bioavailable and free) with bone mass and microarchitecture among primary hyperparathyroidism (PHPT) patients and controls. Subjects and methods: Sixty-four patients in the preoperative period of PHPT and 63 matched controls, who had not taken vitamin D in the last three months. To calculate the bioavailable and free 25OHD, the genetic variants of the vitamin D-binding protein (DBP) were determined. Bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry (DXA). The distributions of total, bioavailable and free 25OHD and their correlation with TBS and DXA were evaluated. Results: PHPT showed BMD and TBS values lower than CTRL in all locations (p < 0.05). There were no statistical differences in the levels of free, bioavailable and total 25OHD between the PHPT and CTRL groups [mean, min-max: 3.4 (1.4-8.6) vs. 3.1 (1.0-9.8) pg/mL, 1.51 (0.43-3.58) vs. 1.41 (0.38-3.48) ng/mL, 22.6 (11.0-39.9) vs. 20.6 (8.9-35.3) ng/dL, respectively; (p > 0.05). The distribution of DBP haplotypes was similar between groups. DXA showed no correlation with any form of 25OHD in both groups. TBS presented a weak correlation with the total 25OHD in PHPT (r = 0.28; p = 0.02) and a moderate correlation with the total, free and bioavailable 25OHD in CTRL (r = 0.42; r = 0.42; r = 0.43; respectively, p < 0.01). Conclusion: The concentrations of total, free and bioavailable 25OHD were similar in both the PHPT and control groups. 25OHD concentrations correlated positively with TBS and not with DXA, especially in controls, suggesting that this method may be more sensitive to assessing the consequences of vitamin D deficiency on bone quality in individuals without PHPT.

ABSTRACT Hypophosphatasia (HPP) is an inherited disease caused by a low activity of tissue-nonspecific alkaline phosphatase, a hydrolase that removes phosphate groups from many molecules. Decreased alkaline phosphatase activity leads to the accumulation of three main metabolites, i.e., pyridoxal 5'-phosphate (PLP), inorganic pyrophosphate (PPi), and phosphoethanolamine. Impairment in PLP dephosphorylation induces seizures, while PPi accumulation inhibits bone mineralization. Clinically, HPP has a wide spectrum of presentations, ranging from neonatal death to an apparent lack of symptoms. This disease is classified into six subtypes according to the age at onset of first signs or symptoms. The clinical manifestations of the disease include rickets-like bone changes, bone demineralization, fragility fractures, reduced muscular strength, chest deformity, pulmonary hypoplasia, nephrolithiasis, nephrocalcinosis, and chondrocalcinosis. Treatment of HPP consists of enzyme replacement therapy. Before this therapy was approved, treatment was palliative and associated with high morbidity and mortality. Asfotase alfa has changed the prognosis of the disease by reducing bone deformity and improving bone mineralization, lung function, and muscle weakness, among other benefits. In adults, teriparatide and anti-sclerostin antibody have been used off-label in selected cases, demonstrating benefit in accelerating fracture healing and in concomitant treatment of osteoporosis. This review summarizes the main aspects of HPP and identifies the particularities of the disease in adult patients.

ABSTRACT Vitamin D deficiency is a general health problem affecting individuals at all stages of life and on different continents. The musculoskeletal effects of vitamin D are well known. Its deficiency causes rickets, osteomalacia, and secondary hyperparathyroidism and increases the risk of fractures. Clinical and experimental evidence suggests that vitamin D performs multiple extraskeletal functions. Several tissues unrelated to calcium and phosphate metabolism express vitamin D receptor (VDR) and are directly or indirectly influenced by 1,25(OH)2D (calcitriol). Some also express the enzyme 1 alpha-hydroxylase (CYP27B1) and produce 1,25(OH)2D, inducing autocrine or paracrine effects. Among the pleiotropic effects of vitamin D are the regulation of cell proliferation and differentiation, hormone secretion, and immune function. In this review, we outline vitamin D physiology and the outcomes of recent large RCTs on its potential extraskeletal effects. Those studies exhibit a need for continued clinical analysis to elucidate whether vitamin D status can influence extraskeletal health. Longer longitudinal follow-up and standardized assays are crucial to better assess potential outcomes.

ABSTRACT Objective: The fibroblast growth factor 23 (FGF23) has been related to biological aging, but data in elderly individuals are scant. We determined the profile of serum FGF23 levels in a population of very-old individuals and studied their correlations with parameters of bone metabolism and health markers, as functional performance. Materials and methods: This cross-sectional study was performed on 182 community dwellers aged ≥ 80 years. Serum levels of FGF23, PTH, calcium, albumin, phosphorus, creatinine, bone markers, and bone mineral density data were analyzed. Physical performance was evaluated with the stationary march (Step), Flamingo, and functional reach tests, along with questionnaires to assess falls and fractures in the previous year, energy expenditure (MET), and the Charlson index (CI). Physical activity was evaluated with the International Physical Activity Questionnaire (IPAQ). Results: Most participants (75%) had FGF23 levels between 30-120 RU/mL (range: 6.0-3,170.0 RU/mL). FGF23 levels correlated with estimated glomerular filtration rate (eGFR; r = -0.335; p = 0.001) and PTH (r = 0.318; p < 0.0001). Individuals with FGF23 in the highest tertile had more falls in the previous year (p = 0.032), worse performance in the Flamingo (p = 0.009) and Step (p < 0.001) tests, worse CI (p = 0.009) and a trend toward sedentary lifestyle (p = 0.056). On multiple regression, FGF23 tertiles remained significant, independently of eGFR, for falls in the previous year, performance in the Flamingo and stationary march tests, lean mass index, and IPAQ classification. Conclusion: In a population of very elderly individuals, FGF23 levels were inversely associated with neuromuscular and functional performances. Higher concentrations were related to more falls, lower muscle strength and aerobic capacity, and poorer balance, regardless of renal function, suggesting a potentially deleterious role of high FGF23 concentrations in musculoskeletal health.

Abstract Objective: To present an updated and evidence-based guideline for the use of dual-energy x-ray absorptiometry (DXA) to assess body composition in clinical practice. Materials and methods: This Official Position was developed by the Scientific Committee of the Brazilian Association of Bone Assessment and Metabolism ( Associação Brasileira de Avaliação Óssea e Osteometabolismo , ABRASSO) and experts in the field who were invited to contribute to the preparation of this document. The authors searched current databases for relevant publications in the area of body composition assessment. In this second part of the Official Position, the authors discuss the interpretation and reporting of body composition parameters assessed by DXA and the use of DXA for body composition evaluation in special situations, including evaluation of children, persons with HIV, and animals. Conclusion: This document offers recommendations for the use of DXA in body composition evaluation, including indications, interpretation, and applications, to serve as a guiding tool in clinical practice and research for health care professionals in Brazil.

RESUMO Objetivo Examinar a associação entre o fator de crescimento de fibroblastos 23 sérico e a capacidade funcional em indivíduos independentes, com 80 anos ou mais. Métodos A capacidade funcional de 144 idosos foi avaliada por meio de Atividades Instrumentais da Vida Diária, testes cognitivos, força de preensão manual e capacidade de levantar de uma cadeira e sentar cinco vezes. O fator de crescimento de fibroblastos 23 foi medido pelo teste ELISA. Resultados Os participantes no tercil mais baixo de fator de crescimento de fibroblastos 23 tiveram a maior média±desvio-padrão da taxa de filtração glomerular estimada, concentração média de hemoglobina mais alta, menor número médio de doenças e menor número de medicamentos utilizados. Em participantes com taxa de filtração glomerular estimada >45mL/minuto/1,73m2, o nível médio do fator de crescimento de fibroblastos 23 foi maior naqueles com 25(OH) vitamina D <20ng/mL do que naqueles com 25(OH) vitamina D ≥20ng/mL (75,6RU/mL±42,8 versus 68,5RU/mL±41,7; p<0,001). Houve aumento na cistatina C sérica média (de 1,3mg/mL±0,3 a 1,5mg/mL±0,3 a 1,7mg/mL±0,4) em função do tercil de fator de crescimento 23 de fibroblastos mais alto (p<0,001). Os níveis de fator de crescimento de fibroblastos 23 não foram significativamente associados à capacidade em testes físicos ou cognitivos. Conclusão Em idosos independentes residentes na comunidade ≥80 anos, o fator de crescimento de fibroblastos 23 foi associado a comorbidades relacionadas à idade e à função renal, mas não à capacidade funcional.

ABSTRACT Objective To examine the association of between serum fibroblast growth factor 23 and the functional capacity among independent individuals, aged 80 or older. Methods The functional capacity of 144 elderly was assessed by Instrumental Activities of Daily Living, cognitive tests, handgrip strength and the timed ability to rise from a chair and sit down five times. Fibroblast growth factor 23 was measured using an ELISA assay. Results Participants in the lowest fibroblast growth factor 23 tertile had the highest mean±standard deviation estimated glomerular filtration rate, the highest mean hemoglobin level, the lowest average number of diseases and the lowest number of medications used. In participants with the estimated glomerular filtration rate >45mL/minute/1.73m2, mean fibroblast growth factor 23 level was higher in those with 25(OH) vitamin D <20ng/mL than in those with 25(OH) vitamin D ≥20ng/mL (75.6RU/mL±42.8 versus 68.5RU/mL±41.7; p<0.001). There was an increase in the mean serum cystatin C (from 1.3mg/mL±0.3 to 1.5mg/mL±0.3 to 1.7mg/mL±0.4) as function of higher fibroblast growth factor 23 tertile (p<0.001). Fibroblast growth factor 23 levels were not significantly associated with capacity in physical or cognitive tests. Conclusion In independent community-dwelling elderly, aged ≥80 years, fibroblast growth factor 23 was associated with aged-related comorbidities and renal function but not with functional capacity.

ABSTRACT Antiresorptive therapy is the main form of prevention of osteoporotic or fragility fractures. Medication-related osteonecrosis of the jaw (MRONJ) is a relatively rare but severe adverse reaction to antiresorptive and antiangiogenic drugs. Physicians and dentists caring for patients taking these drugs and requiring invasive procedures face a difficult decision because of the potential risk of MRONJ. The aim of this study was to discuss the risk factors for the development of MRONJ and prevention of this complication in patients with osteoporosis taking antiresorptive drugs and requiring invasive dental treatment. For this goal, a task force with representatives from three professional associations was appointed to review the pertinent literature and discuss systemic and local risk factors, prevention of MRONJ in patients with osteoporosis, and management of established MRONJ. Although scarce evidence links the use of antiresorptive agents in the context of osteoporosis to the development of MRONJ, these agents are considered a risk factor for this complication. Despite the rare reports of MRONJ in patients with osteoporosis, the severity of symptoms and impact of MRONJ in the patients' quality of life make it imperative for health care professionals to consider this complication when planning invasive dental procedures.

SUMMARY Hypophosphatasia (HPP) is a rare disease with a high mortality rate in its severe forms. It is caused by mutations within the gene encoding the tissue-nonspecific alkaline phosphatase (TNSALP), an enzyme responsible for bone mineralization. In 2015, the Food and Drug Administration approved the use of asfotase alfa, the first medication showing benefit in the treatment of HPP. We describe a case with a 2-year follow-up of the first Brazilian child treated with asfotase alfa. A 5-year-old boy, born to consanguineous parents, was diagnosed with HPP at the age of 20 months. During prenatal ultrasonography, polyhydramnios and shortening of long bones were detected. After birth, he presented delayed motor development, repeated respiratory infections, and bone deformities. At the age of 2 years and 8 months, he started walking and had already lost his primary teeth. He had reduced levels of alkaline phosphatase (ALP), elevated levels of pyridoxal 5’-phosphate (PLP), and a p.Ala33Val (c.98C>T) missense mutation in homozygosis in the TNSALP gene. His parents and sister also had reduced ALP levels, high PLP levels, and the same mutation in heterozygosis. His father and sister were healthy, and his mother was diagnosed with rickets in childhood, which resulted in short physical stature and lower limb deformities. The patient was started on asfotase alfa at the age of 2 years and 10 months. After 2 years of treatment, he improved his motor skills, had no further episodes of severe respiratory infection, and showed improved radiological findings of rickets, without any severe side effect.

ABSTRACT The effects of vitamin D on the musculoskeletal system are well established. Its deficiency causes osteomalacia, secondary hyperparathyroidism, and an increased risk for fractures and falls. However, clinical and experimental evidence points to extra-skeletal actions of vitamin D, including on immune and respiratory systems. Thus, during this COVID-19 pandemic, a possible deleterious role of vitamin D deficiency has been questioned. This paper aims to present a brief review of the literature and discuss, based on evidence, the role of vitamin D in the lung function and in the prevention of respiratory infections. Relevant articles were searched in the databases MEDLINE/PubMed and SciELO/LILACS. The mechanisms of vitamin D action in the immune system response will be discussed. Clinical data from systematic reviews and meta-analyses show benefits in the prevention of respiratory infections and improvement of pulmonary function when vitamin D-deficient patients are supplemented. At the time of writing this paper, no published data on vitamin D supplementation for patients with COVID-19 have been found. Vitamin D supplementation is recommended during this period of social isolation to avoid any deficiency, especially in the context of bone outcomes, aiming to achieve normal values of 25(OH)D. The prevention of respiratory infections and improvement of pulmonary function are additional benefits observed when vitamin D deficiency is treated. Thus far, any protective effect of vitamin D specifically against severe COVID-19 remains unclear. We also emphasize avoiding bolus or extremely high doses of vitamin D, which can increase the risk of intoxication without evidence of benefits.

ABSTRACT Hypovitaminosis D is a common condition with a negative impact on health. This statement, prepared by experts from the Brazilian Society of Endocrinology and Metabolism and the Brazilian Society of Clinical Pathology/Laboratory Medicine, includes methodological aspects and limitations of the measurement of 25-hydroxyvitamin D [25(OH)D] for identification of vitamin D status, and identifies individuals at increased risk for deficiency of this vitamin in whom 25(OH)D measurement is recommended. For the general population, 25(OH)D levels between 20 and 60 ng/mL are considered normal, while individuals with levels below 20 ng/mL are considered to be vitamin D deficient. This statement identifies potential benefits of maintaining 25(OH)D levels > 30 ng/mL in specific conditions, including patients aged > 65 years or pregnant, those with recurrent falls, fragility fractures, osteoporosis, secondary hyperparathyroidism, chronic kidney disease, or cancer, and individuals using drugs with the potential to affect the vitamin D metabolism. This statement also calls attention to the risk of vitamin D intoxication, a life-threatening condition that occurs at 25(OH)D levels above 100 ng/mL

ABSTRACT Objective: To verify which component of body composition (BC) has greater influence on postmenopausal women bone mineral density (BMD). Subjects and methods: Four hundred and thirty women undergoing treatment for osteoporosis and 513 untreated women, except for calcium and vitamin D. Multiple linear regression analysis was performed in order to correlated BMD at lumbar spine (LS), total femur (FT), femoral neck (FN) with body mass (BM), total lean mass (LM) and total fat mass (FM), all determined by DXA. Results: BM significantly correlated with all bone sites in untreated and treated women (r = 0.420 vs 0.277 at LS; r = 0.490 vs 0.418 at FN, r = 0.496 vs 0.414 at FT, respectively). In untreated women, the LM correlated better than FM with all sites, explaining 179% of LS; 32.3% of FN and 30.2% of FT; whereas FM explained 13.2% of LS; 277% of FN, 23.4% of FT In treated women, correlations with BC were less relevant, with the LM explaining 6.7% of BMD at LS; 15.2% of FN, 16% of FT, whereas the FM explained 8.1% of LS; 179% of FN and 176% of FT. Conclusion: LM in untreated women was better predictor of BMD than FM, especialy for distal femur, where it explained more than 30% of the BMD, suggesting that maintaining a healthy muscle mass may contribute to decrease osteoporosis risk. Treatment with anti-osteoporotic drugs seems to mask these relationships. Arch Endocrinol Metab. 2018;62(4):431-7

ABSTRACT Objective To present an update on the diagnosis and treatment of hypoparathyroidism based on the most recent scientific evidence. Materials and methods The Department of Bone and Mineral Metabolism of the Sociedade Brasileira de Endocrinologia e Metabologia (SBEM; Brazilian Society of Endocrinology and Metabolism) was invited to prepare a document following the rules set by the Guidelines Program of the Associação Médica Brasileira (AMB; Brazilian Medical Association). Relevant papers were retrieved from the databases MEDLINE/PubMed, LILACS, and SciELO, and the evidence derived from each article was classified into recommendation levels according to scientific strength and study type. Conclusion An update on the recent scientific literature addressing hypoparathyroidism is presented to serve as a basis for the diagnosis and treatment of this condition in Brazil.

RESUMO Introdução: A vitamina D é considerada um pré-hormônio e apresenta papel crucial na homeostase do cálcio e, consequentemente, na saúde óssea. A maior fonte de vitamina D é a pele, em resposta à luz solar. Apenas pequenas quantidades dessa vitamina são encontradas em alguns alimentos (especialmente peixes gordurosos), o que faz com que a disponibilidade da vitamina D na dieta seja limitada. Estudos populacionais brasileiros demonstram que a prevalência da hipovitaminose D no nosso país é elevada. Objetivo: Definição dos intervalos de referência para vitamina D [25(OH)D]. Discussão: Consenso de especialistas - revisão da literatura. Conclusão: A padronização dos intervalos de referência é fundamental para o correto diagnóstico e tratamento da hipovitaminose D.

ABSTRACT Introduction: Vitamin D is considered a pre-hormone and plays a crucial role in calcium homeostasis and, consequently, in bone health. The best source of vitamin D is the skin in response to sunlight. Only small amounts of this vitamin are found in some foods (especially fatty fish), which makes availability of vitamin D in the diet limited. Brazilian population studies show that the prevalence of hypovitaminosis D in our country is high. Objective: To define the reference intervals for vitamin D [25(OH)D]. Discussion: Consensus of specialists - literature review. Conclusion: The standardization of reference intervals is fundamental for the correct diagnosis and treatment of hypovitaminosis D.

ABSTRACT Objective This study sought to investigate the effects of vitamin D supplementation and aquatic exercise on pulmonary function in postmenopausal women. Materials and methods This prospective and controlled study included 104 women (62 ± 6.5 years) divided into three groups: a control group lacking vitamin D and calcium supplementation which remained sedentary (CG; n = 17); a control group receiving vitamin D and calcium supplementation which remained sedentary (CDG, n = 33); and a group that completed aquatic exercises three times a week and received vitamin D and calcium supplementation (DTG, n = 54). Data before and after 6 months of the study were analyzed, including serum 25-hydroxyvitamin D (25(OH)D) and calcium concentrations, peak expiratory flow (PEF), forced vital capacity (FVC), and cirtometry. Results We observed significant increases in 25(OH)D concentrations in CDG (52.9 ± 2.4 to 69.1 ± 2.2; nmol/L; p < 0.0001) and DTG groups (55.5 ± 3 to 71.5 ± 3 nmol/L; p < 0.0001). PEF increased by 7 ± 2% (p = 0.0080) in CDG group and 11 ± 2% (p < 0.0001) in DTG group, whereas FVC increased by 7 ± 2% (p = 0.0016) in the CDG group and 10 ± 2% (p < 0.0001) in the DTG group, whereas CG had no changes in any of these parameters. The increment value of cirtometry in DTG group (+43 ± 3%) were significantly (p < 0.0001) higher than those in CG (−4 ± 8%) and CDG (+4 ± 9%) groups. Conclusion Our data suggest that vitamin D supplementation improves pulmonary function parameters in postmenopausal women.