Impaired bone microarchitecture and strength in patients with tumor-induced osteomalacia.

Some studies based on bone biopsy have demonstrated that in patients with tumor-induced osteomalacia (TIO) the mineralization process of the bone matrix is profoundly disturbed. However, the interrelationship between clinical and biochemical features and bone microarchitecture in this disease needs further analysis. With this purpose in mind, we set out three objectives: (i) to determine bone microarchitecture and estimated bone strength in a group of patients with tumor-induced osteomalacia using high-resolution peripheral quantitative computed tomography (HR-pQCT) and finite element analysis (FEA), (ii) to investigate correlations between duration of disease, biochemical features, bone density, HR-pQCT and FEA parameters, and (iii) to compare HR-pQCT and FEA parameters with a healthy control group. Ten patients with TIO were included. All patients had non-resolved disease. At the distal radius, all bone microarchitecture parameters were significantly affected in patients with TIO in comparison with healthy controls. At the distal tibia, all parameters were significantly impaired, except for trabecular thickness. All the parameters were more affected in the distal tibia than in the distal radius. Women with TIO (n = 7) had significantly lower bone strength parameters than healthy controls. In men (n = 3), bone strength parameters were significantly lower than in the control group at the distal tibia. Alkaline phosphatase levels exhibited a negative correlation with microarchitecture parameters, failure load, and stiffness. Higher levels of parathyroid hormone correlated with poorer microarchitecture parameters. We believe that in TIO, hormonal disturbances and the lack of mechanical stimulus specially converge to generate an extremely harmful combination for bone health. © 2021 American Society for Bone and Mineral Research (ASBMR).

Burden of Disease in Patients With Tumor-Induced Osteomalacia.

Tumor-induced osteomalacia (TIO) is a chronic condition associated with muscle weakness and long-term disability. We conducted a cross-sectional study of patients diagnosed with TIO who had been referred to our institution between May 2018 and December 2019. Our aim was to assess health-related quality of life (HRQoL), fatigue, pain, and muscle mass and strength in these patients. Detailed information was obtained regarding general characteristics, initial symptoms and biochemical parameters measured at diagnosis and on the first visit to our institution. Fatigue was assessed using the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue) scale, pain using the Brief Pain Inventory-Short Form (BPI-sf) scale and HRQoL by the 36-item Short Form survey (SF-36) questionnaire. Eight patients were included in the study: three without tumor localization, four with nonremission after surgery, and one with clinical recurrence 2 years after surgery. Fatigue experienced by patients with TIO was significantly higher compared to the general population (p ˂ .0001). The physical summary measure of the SF-36 showed significantly lower values than those of the Argentinean population with chronic conditions (mean 20.4 versus 45.9, p < .0001). According to the BPI-sf, patients with TIO have moderate average pain and the pain interferes severely with walking, general activities, work, and mood. Seven patients had a diagnosis of sarcopenia, four of which had severe sarcopenia. To our best knowledge, this is the first study aimed to quantify fatigue, pain, HRQoL, and muscle mass and strength in a group of patients with TIO. We hope our results contribute to a better understanding of the burden of disease and to establish a basis for future studies-with larger samples-which will make it possible to assess the efficacy of therapeutic interventions for these conditions. © 2020 American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

VIH y salud ósea / HIV and bone health

Con el advenimiento de la terapia antirretroviral, el pronóstico y la sobrevida de los pacientes infectados con el virus de la inmunodeficiencia humana (VIH) han cambiado de manera radical, por lo cual en la actualidad se evidencia un aumento en el riesgo de padecer enfermedades no relacionadas con el VIH como, por ejemplo, la osteoporosis. La disminución de la densidad mineral ósea (DMO) se observa en el 40-90% de las personas infectadas por el VIH, con una prevalencia de osteopenia y osteoporosis del 52 y 15%, respectivamente. Esta población de pacientes tiene un mayor riesgo de fracturas (60%) en comparación con personas no infectadas y un riesgo de fracturas vertebrales 2,3 veces mayor que en la población general. El tenofovir fumarato se asoció con un aumento de pérdida renal de fósforo e hiperparatiroidismo secundario. El efavirenz y los inhibidores de proteasas (IP) afectan el metabolismo de la vitamina D; actúan a nivel enzimático aumentando la expresión de la enzima CYP24 que lleva a producción de vitamina D inactiva. El FRAX es una herramienta sencilla y accesible, por lo que su uso está recomendado en pacientes con VIH. Además de las medidas higiénico-dietéticas, actividad física, calcio y vitamina D, el uso de bifosfonatos está indicado en el tratamiento de la osteoporosis en estos pacientes. (AU)

With the advent of antiretroviral therapy, the prognosis and survival of patients infected with the human immunodeficiency virus (HIV) have radically changed, which is why there is now evidence of an increased risk of suffering from diseases not related to HIV such as osteoporosis. The decrease in bone mineral density (BMD) is observed in 40-90% of people infected with HIV, with a prevalence of osteopenia and osteoporosis of 52 and 15%, respectively. This patient population has a 60% higher risk of fractures compared to uninfected people and a risk of vertebral fractures 2.3 times higher than in the general population. Tenofovir fumarate administration is associated with increased renal phosphorus loss and secondary hyperparathyroidism. Efavirenz and protease inhibitors (IP) affect the metabolism of vitamin D, they act at the enzymatic level by increasing the expression of the CYP24 enzyme that leads to the production of inactive vitamin D. The FRAX is a simple and accessible tool, so its use is recommended in patients with HIV and in addition to dietary hygiene measures, physical activity, calcium, and vitamin D, the use of bisphosphonates is indicated in the treatment of osteoporosis in these patients. (AU)

Prevalencia de enfermedades tiroideas en una población del área metropolitana de Buenos Aires / Prevalence of thyroid diseases in a population of the metropolitan area of Buenos Aires

La prevalencia de alteraciones morfológicas palpables tiroideas no supera el 8% en la población adulta. En el Hospital de Clínicas de la Universidad de Buenos Aires se llevó a cabo un programa gratuito para la detección de enfermedades tiroideas, convocándose a sujetos que desconocieran antecedentes tiroideos. Nuestro objetivo fue establecer la frecuencia de patología morfológica palpable tiroidea, en una población seleccionada de pacientes, y comparar dichos resultados con los hallazgos de un programa de detección similar, realizado en el año 2001¹. Adicionalmente, evaluar la prevalencia de alteraciones funcionales y de autoinmunidad tiroidea. Los individuos que concurrieron se dividieron en 3 grupos: Grupo 1 (n = 186) pacientes con antecedentes personales de enfermedad tiroidea conocida (excluidos del análisis); Grupo 2 (n = 184) sujetos con antecedentes familiares, otras enfermedades autoinmunes, o sintomatología que pudiera atribuirse a alteración de la función tiroidea (grupo inducido), y Grupo 3 (n = 288) sujetos que consultaron por mera curiosidad (grupo random). La función y autoinmunidad tiroidea se evaluó en 144 participantes del Grupo 3, citados al azar. En el grupo random, la prevalencia de alteraciones morfológicas tiroideas, detectadas por palpación, fue del 11,09%. Al comparar estos resultados con los obtenidos 12 años atrás en un estudio similar, realizado en nuestro hospital, no se encontraron diferencias estadísticamente significativas (8,7 vs. 11,09%; p = 0,25). En cuanto a la función tiroidea, se halló hipotiroidismo subclínico en el 6,25%, hipertiroidismo subclínico en el 0,7% y autoinmunidad en el 11% de los sujetos evaluados. En conclusión, la prevalencia de alteraciones palpables de la glándula tiroides no cambió en laúltima década. Esta investigación realizada en una población correctamente seleccionada constituye una herramienta útil para referencias futuras como población control en Argentina.

The prevalence of palpable thyroid morphological abnormalities does not exceed 8% in the adult population. A free program was conducted in the Hospital de Clínicas (University of Buenos Aires) for the detection of thyroid diseases, inviting subjects who were unaware of a history of these diseases. The aim was to establish the frequency of goitre in the selected population, as well as to evaluate the prevalence of functional disorders and thyroid autoimmunity, and to compare these results with the findings of a similar study performed in 2001¹. The subjects were divided into three groups: Group 1 (n = 186) patients with a history of previously known thyroid disorders (excluded subjects); Group 2 (n = 184) subjects with a family history of thyroid disease, other autoimmune diseases, or symptoms that could be attributed to changes in thyroid function (Induced Group), and Group 3 (n = 288) subjects who participated in this program due to mere curiosity (Random Group). Autoimmunity and thyroid function was assessed in 144 randomly selected participants in Group 3. In Group 3, the prevalence of morphological alterations of the thyroid gland was 11.09%. Comparing these results with those obtained 12 years ago in a similar study performed in our hospital, no statistically significant differences were found when the prevalence of morphological thyroid alterations were compared (8.7% vs 11.09%, p=.25). As for thyroid function, subclinical hypothyroidism was found in 6.25%, subclinical hyperthyroidism in 0.7%, and autoimmunity in 11% of subjects evaluated. It was concluded that the prevalence of palpable thyroid abnormalities had not change in the last decade. This study, made in a correctly selected population, is a useful tool for future reference as a control population in Argentina.