Manejo de la osteoporosis en el paciente con enfermedad renal crónica (Estudio ERCOS): un desafío en la asistencia nefrológica / Osteoporosis management in patients with chronic kidney disease (ERCOS Study): A challenge in nephrological care

La valoración del riesgo de fractura del paciente con enfermedad renal crónica (ERC) ha sido incluida en el complejo Chronic Kidney Disease-Mineral and Bone Disorders (CKD-MBD) en guías nefrológicas internacionales y nacionales, sugiriéndose por primera vez la evaluación de la densidad mineral ósea (DMO) si los resultados pueden condicionar la toma de decisiones terapéuticas. Sin embargo, existe muy poca información en práctica clínica real en esta población. El objetivo principal del estudio ERC-Osteoporosis (ERCOS) es describir el perfil de los pacientes con ERC G3-5D con osteoporosis (OP) y/o fracturas por fragilidad atendidos en consultas especializadas de nefrología, reumatología y medicina interna en España. Participaron 15 centros y se incluyeron 162 pacientes (siendo en su mayoría mujeres [71,2%] posmenopáusicas [98,3%]) con una mediana de edad de 77 años. La mediana del filtrado glomerular estimado (FGe) fue de 36ml/min/1,73m2 y el 38% de pacientes incluidos estaban en diálisis. Destacamos la elevada frecuencia de fracturas por fragilidad prevalentes ([37,7%), principalmente vertebrales [52,5%] y de cadera 24,6%]), el antecedente desproporcionado de pacientes con enfermedad glomerular en comparación con series puramente nefrológicas (corticoides) y el infratratamiento para la prevención de fracturas, fundamentalmente en consultas nefrológicas. Este estudio supone una inmediata llamada a la acción con la difusión de las nuevas guías clínicas, más proactivas, y subraya la necesidad de homogeneizar el enfoque asistencial/terapéutico multidisciplinar coordinado de estos pacientes de un modo eficiente para evitar las actuales discrepancias y el nihilismo terapéutico. (AU)

Fracture risk assessment in patients with chronic kidney disease (CKD) has been included in the Chronic Kidney Disease-Mineral and Bone Disorders (CKD-MBD) complex in international and national nephrology guidelines, suggesting for the first time the assessment of bone mineral density (BMD) if the results will impact treatment decisions. However, there is very little information on actual clinical practice in this population. The main objective of the ERC-Osteoporosis (ERCOS) study is to describe the profile of patients with CKD G3-5D with osteoporosis (OP) and/or fragility fractures treated in specialized nephrology, rheumatology and internal medicine clinics in Spain. Fifteen centers participated and 162 patients (mostly women [71.2%] postmenopausal [98.3%]) with a median age of 77 years were included. Mean estimated glomerular filtration rate (eGFR) was 36ml/min/1.73m2 and 38% of the included patients were on dialysis. We highlight the high frequency of prevalent fragility fractures ([37.7%], mainly vertebral [52.5%] and hip [24.6%]), the disproportionate history of patients with glomerular disease compared to purely nephrological series (corticosteroids) and undertreatment for fracture prevention, especially in nephrology consultations. This study is an immediate call to action with the dissemination of the new, more proactive, clinical guidelines, and underlines the need to standardize a coordinated and efficient multidisciplinary care/therapeutic approach to these patients to avoid current discrepancies and therapeutic nihilism. (AU)

Osteoporosis management in patients with chronic kidney disease (ERCOS Study): A challenge in nephrological care.

Fracture risk assessment in patients with chronic kidney disease (CKD) has been included in the CKD-MBD ("Chronic Kidney Disease-Mineral and Bone Disorders") complex in international and national nephrology guidelines, suggesting for the first time the assessment of bone mineral density (BMD) if the results can influence therapeutic decision-making. However, there is very little information on actual clinical practice in this population. The main objective of the ERCOS (ERC-Osteoporosis) study is to describe the profile of patients with CKD G3-5D with osteoporosis (OP) and/or fragility fractures treated in specialized nephrology, rheumatology and internal medicine clinics in Spain. Fifteen centers participated and 162 patients (mostly women [71.2%] postmenopausal [98.3%]) with a median age of 77 years were included. Mean estimated glomerular filtration rate (eGFR) was 36 mL/min/1.73 m2 and 38% of the included patients were on dialysis. We highlight the high frequency of prevalent fragility fractures [37.7%), mainly vertebral (52.5%) and hip (24.6%)], the disproportionate history of patients with glomerular disease compared to purely nephrological series (corticosteroids) and undertreatment for fracture prevention, especially in nephrology consultations. This study is an immediate call to action with the dissemination of the new, more proactive, clinical guidelines, and underlines the need to standardize a coordinated and multidisciplinary care/therapeutic approach to these patients in an efficient way to avoid current discrepancies and therapeutic nihilism.

[Characterization of hospitalized patients with acute kidney injury associated with COVID-19 in Spain: Renal replacement therapy and mortality. FRA-COVID SEN Registry Data]. / Caracterización de la población con fracaso renal agudo durante la hospitalización por COVID-19 en España: tratamiento renal sustitutivo y mortalidad. Datos del Registro FRA-COVID SEN.

Background and objectives: Acute kidney injury (AKI) is common among hospitalized patients with COVID-19 and associated with worse prognosis. The Spanish Society of Nephrology created the AKI-COVID Registry to characterize the population admitted for COVID-19 that developed AKI in Spanish hospitals. The need of renal replacement therapy (RRT) therapeutic modalities, and mortality in these patients were assessed. Material and method: In a retrospective study, we analyzed data from the AKI-COVID Registry, which included patients hospitalized in 30 Spanish hospitals from May 2020 to November 2021. Clinical and demographic variables, factors related to the severity of COVID-19 and AKI, and survival data were recorded. A multivariate regression analysis was performed to study factors related to RRT and mortality. Results: Data from 730 patients were recorded. A total of 71.9% were men, with a mean age of 70 years (60-78), 70.1% were hypertensive, 32.9% diabetic, 33.3% with cardiovascular disease and 23.9% had some degree of chronic kidney disease (CKD). Pneumonia was diagnosed in 94.6%, requiring ventilatory support in 54.2% and admission to the ICU in 44.1% of cases.The median time from the onset of COVID-19 symptoms to the appearance of AKI (37.1% KDIGO I, 18.3% KDIGO II, 44.6% KDIGO III) was 6 days (4-10). A total of 235 (33.9%) patients required RRT: 155 patients with continuous renal replacement therapy, 89 alternate-day dialysis, 36 daily dialysis, 24 extended hemodialysis and 17 patients with hemodiafiltration. Smoking habit (OR 3.41), ventilatory support (OR 20.2), maximum creatinine value (OR 2.41) and time to AKI onset (OR 1.13) were predictors of the need for RRT; age was a protective factor (0.95). The group without RRT was characterized by older age, less severe AKI, shorter kidney injury onset and recovery time (p < 0.05). 38.6% of patients died during hospitalization; serious AKI and RRT were more frequent in the death group. In the multivariate analysis, age (OR 1.03), previous chronic kidney disease (OR 2.21), development of pneumonia (OR 2.89), ventilatory support (OR 3.34) and RRT (OR 2.28) were predictors of mortality while chronic treatment with ARBs was identified as a protective factor (OR 0.55). Conclusions: Patients with AKI during hospitalization for COVID-19 had a high mean age, comorbidities and severe infection. We defined two different clinical patterns: an AKI of early onset, in older patients that resolves in a few days without the need for RRT; and another more severe pattern, with greater need for RRT, and late onset, which was related to greater severity of the infectious disease. The severity of the infection, age and the presence of CKD prior to admission were identified as risk factors for mortality in these patients. In addition chronic treatment with ARBs was identified as a protective factor for mortality.

Silver jubilee: 25 years of the first demonstration of the direct effect of phosphate on the parathyroid cell.

Although phosphorus is an essential element for life, it is not found in nature in its native state but rather combined in the form of inorganic phosphates (PO43-), with tightly regulated plasma levels that are associated with deleterious effects and mortality when these are out of bounds. The growing interest in the accumulation of PO43- in human pathophysiology originated in its attributed role in the pathogenesis of secondary hyperparathyroidism (SHPT) in chronic kidney disease. In this article, we review the mechanisms by which this effect was justified and we commemorate the important contribution of a Spanish group led by Dr. M. Rodríguez, just 25 years ago, when they first demonstrated the direct effect of PO43- on the regulation of the synthesis and secretion of parathyroid hormone by maintaining the structural integrity of the parathyroid glands in their original experimental model. In addition to demonstrating the importance of arachidonic acid (AA) and the phospholipase A2-AA pathway as a mediator of parathyroid gland response, these findings were predecessors of the recent description of the important role of PO43- on the activity of the calcium sensor-receptor, and also fueled various lines of research on the importance of PO43- overload not only for the pathophysiology of SHPT but also in its systemic pathogenic role.

Hiporrespuesta o resistencia a la acción de la hormona paratiroidea en la enfermedad renal crónica / Hyporesponsiveness or resistance to the action of parathyroid hormone in chronic kidney disease

El hiperparatiroidismo secundario es uno de los componentes integrales de las alteraciones del metabolismo óseo-mineral en la enfermedad renal crónica (ERC) o complejo chronic kidney disease-mineral bone disorder. Se ha demostrado que en el desarrollo y progresión del hiperparatiroidismo secundario intervienen muchos factores, estrechamente interrelacionados, pero la presencia e importancia de la hiporrespuesta (o resistencia) a la acción de la hormona paratiroidea (PTH) es poco comprendida. En esta revisión analizaremos sus antecedentes, factores que intervienen, así como alguno de los mecanismos moleculares que podrían explicarla. La presencia de resistencia a la acción biológica de la PTH no es única en la ERC, ya que también se presenta para otras hormonas, habiéndose incluso usado el término de «uremia como una enfermedad de receptores». Esta hiporrespuesta a la PTH tiene importantes implicaciones clínicas, dado que no solo permite explicar parte de la patogenia progresiva de la hipersecreción de PTH e hiperplasia paratiroidea, sino también la creciente prevalencia de enfermedad ósea adinámica en la población con ERC. De este modo, subrayamos la importancia de controlar, sin normalizar completamente, los niveles de PTH en los distintos estadios de ERC, dado que un cierto incremento de sus niveles supone inicialmente una adaptación clínica. Futuros estudios a nivel molecular sobre la uremia, o la reciente descripción del efecto directo del fosfato sobre la actividad del receptor sensor de calcio como sensor de fosfato, podrían resultar valiosos incluso más allá de explicar la hiporrespuesta a la PTH en la ERC. (AU)

Secondary hyperparathyroidism (SHPT) is an integral component of the chronic kidney disease–mineral and bone disorder (CKD–MBD). Many factors have been associated with the development and progression of SHPT but the presence of skeletal or calcemic resistance to the action of PTH in CKD has often gone unnoticed. The term hyporesponsiveness to PTH is currently preferred and, in this chapter, we will not only review the scientific timeline but also some of the molecular mechanisms behind. Moreover, the presence of resistance to the biological action of PTH is not unique in CKD since resistance to other hormones has also been described (“uremia as a receptor disease”). This hyporesponsiveness carries out important clinical implications since it explains, at least partially, not only the progressive nature of the pathogenesis of CKD-related PTH hypersecretion and parathyroid hyperplasia but also the increasing prevalence of adynamic bone disease in the CKD population. Therefore, we underline the importance of PTH control in all CKD stages, but not aiming to completely normalize PTH levels since a certain degree of SHPT may represent an adaptive clinical response. Future studies at the molecular level, i.e. on uremia, or the recent description of the calcium-sensing receptor as a phosphate sensor, may become of great value beyond their significance to explain just the hyporesponsiveness to PTH in CKD. (AU)

Clinical Approach to Vascular Calcification in Patients With Non-dialysis Dependent Chronic Kidney Disease: Mineral-Bone Disorder-Related Aspects.

Chronic kidney disease (CKD) is associated with a very high morbimortality, mainly from cardiovascular origin, and CKD is currently considered in the high- or very high risk- cardiovascular risk category. CKD-mineral and bone disorders (CKD-MBDs), including vascular and/or valvular calcifications, are also associated with these poor outcomes. Vascular calcification (VC) is very prevalent (both intimal and medial), even in non-dialysis dependent patients, with a greater severity and more rapid progression. Simple X-ray based-scores such as Adragão's (AS) are useful prognostic tools and AS (even AS based on hand-X-ray only) may be superior to the classic Kauppila's score when evaluating non-dialysis CKD patients. Thus, in this mini-review, we briefly review CKD-MBD-related aspects of VC and its complex pathophysiology including the vast array of contributors and inhibitors. Furthermore, although VC is a surrogate marker and is not yet considered a treatment target, we consider that the presence of VC may be relevant in guiding therapeutic interventions, unless all patients are treated with the mindset of reducing the incidence or progression of VC with the currently available armamentarium. Avoiding phosphate loading, restricting calcium-based phosphate binders and high doses of vitamin D, and avoiding normalizing (within the normal limits for the assay) parathyroid hormone levels seem logical approaches. The availability of new drugs and future studies, including patients in early stages of CKD, may lead to significant improvements not only in patient risk stratification but also in attenuating the accelerated progression of VC in CKD.

Real-world management of hyperphosphataemia with sucroferric oxyhydroxide: the VELREAL multicentre study.

BACKGROUND: The efficacy and safety of sucroferric oxyhydroxide (SO) have been reported in clinical trials. However, real-life data are scarce. This study presents data on the use, efficacy and safety of SO in real clinical practice. METHODS: We performed a retrospective multicentre study, without any influence on the prescription decisions, that included 220 patients from 11 Spanish centres. Demographic, treatment, analytical and nutritional parameters and adherence, side effects and dropout rates were collected during 6 months. RESULTS: SO was initiated due to inadequate control of serum phosphate (P) in 70% of participants and in 24.5% to reduce the number of tablets. Monotherapy with SO increased from 44% to 74.1%, with a reduction in the average daily number of sachets/tablets from six to two. Serum P decreased by 20% (4.6 ± 1.2 versus 5.8 ± 1.3 mg/dL; P < 0.001), with a significant reduction in intact parathyroid hormone levels (P < 0.01). The percentage of patients with adequate serum P control at threshold levels of 5 and 4.5 mg/dL increased by 45.4% and 35.9%, respectively. Serum ferritin was not modified, while the transferrin saturation index increased significantly (P = 0.04). Serum albumin and normalized protein catabolic rate, when normalized by serum P, increased, averaging 37% and 39%, respectively (P < 0.001). Adherent patients increased from 28.2% to 52.7%. Adverse effects were reported by 14.1% of participants, with abandonment of treatment in 9.5%. CONCLUSIONS: The use of SO in real-life results in better control of serum P, a reduction in the number of tablets and an improvement in therapeutic adherence. In addition, it may be beneficial with regards to secondary hyperparathyroidism and nutritional status.

Hyporesponsiveness or resistance to the action of parathyroid hormone in chronic kidney disease.

Secondary hyperparathyroidism (SHPT) is an integral component of the chronic kidney disease-mineral and bone disorder (CKD-MBD). Many factors have been associated with the development and progression of SHPT but the presence of skeletal or calcemic resistance to the action of PTH in CKD has often gone unnoticed. The term hyporesponsiveness to PTH is currently preferred and, in this chapter, we will not only review the scientific timeline but also some of the molecular mechanisms behind. Moreover, the presence of resistance to the biological action of PTH is not unique in CKD since resistance to other hormones has also been described ("uremia as a receptor disease"). This hyporesponsiveness carries out important clinical implications since it explains, at least partially, not only the progressive nature of the pathogenesis of CKD-related PTH hypersecretion and parathyroid hyperplasia but also the increasing prevalence of adynamic bone disease in the CKD population. Therefore, we underline the importance of PTH control in all CKD stages, but not aiming to completely normalize PTH levels since a certain degree of SHPT may represent an adaptive clinical response. Future studies at the molecular level, i.e. on uremia or the recent description of the calcium-sensing receptor as a phosphate sensor, may become of great value beyond their significance to explain just the hyporesponsiveness to PTH in CKD.

Detección de las calcificaciones cardiovasculares: ¿una herramienta útil para el nefrólogo? / Detection of cardiovascular calcifications: Is it a useful tool for nephrologists?

La enfermedad renal crónica (ERC) ha servido de modelo y fuente de conocimiento sobre los mecanismos, la relevancia clínica y progresión acelerada de los procesos de la calcificación cardiovascular (CV), así como de sus repercusiones en la práctica clínica, aunque se trate de un fenómeno tardío y secundario de osificación sobre el que solo disponemos de evidencias circunstanciales. En esta amplia revisión se describen primero los tipos de calcificación CV que afectan al paciente con ERC y se analiza cómo su presencia está directamente asociada a eventos CV y a un aumento de la mortalidad de estos pacientes. Asimismo, justificamos la valoración de la calcificación CV en la práctica clínica nefrológica habitual, al entender que es un predictor importante de la evolución clínica de estos pacientes, y consideramos que la valoración de las calcificaciones CV es una herramienta que puede y debe ser utilizada por el nefrólogo para la toma individualizada de decisiones terapéuticas en un momento en que se requiere cada vez más de una medicina personalizada (AU)

Chronic kidney disease (CKD) has been used as a model and source of knowledge concerning the mechanisms, clinical relevance and accelerated progression of cardiovascular (CV) calcification, as well as its consequences in clinical practice, despite we know that it is a late secondary ossification phenomenon and only circumstantial evidence is available. In this comprehensive review, we firstly describe the types of CV calcification which affect CKD patients, and we analyse how its presence is directly associated with CV events and increased mortality in these patients. We also justify the use of CV calcification assessment in regular nephrology clinical practice, because CV calcification is an important predictor of clinical outcome in these patients. Consequently, we believe that CV calcification assessment is a tool that could and should be used by nephrologists when making a decision concerning individual patients, consistent with the current trend of an ever-more-personalised therapeutic approach (AU)

Calcificaciones cardiovasculares en la enfermedad renal crónica: Potenciales implicaciones terapéuticas / Cardiovascular calcifications in chronic kidney disease: Potential therapeutic implications

La calcificación cardiovascular (CV) es una condición muy prevalente en todos los estadios de la enfermedad renal crónica (ERC) y se asocia directamente a una mayor morbimortalidad CV y global. En la primera parte de esta revisión hemos mostrado cómo las calcificaciones CV son una característica destacada del complejo CKD-MBD (chronic kidney disease-mineral and bone disorders) así como un predictor superior de la evolución clínica de nuestros pacientes. No obstante, es necesario también demostrar que la calcificación CV es un factor de riesgo modificable y con la posibilidad, como mínimo, de poder disminuir su progresión (o al menos no agravarla) con maniobras iatrogénicas. Aunque estrictamente solo se disponga de evidencias circunstanciales, sabemos que el uso de determinados fármacos puede modificar la progresión de las calcificaciones CV, aunque no se ha demostrado un vínculo directo causal sobre la mejoría de la supervivencia. En este sentido, el uso de quelantes del fósforo no cálcicos ha demostrado reducir la progresión de las calcificaciones CV en comparación con el uso liberal de quelantes cálcicos en varios ensayos clínicos aleatorizados. Por otra parte, aunque solo a nivel experimental, los activadores selectivos del receptor de la vitamina D parecen mostrar un mayor margen terapéutico contra la calcificación CV. Finalmente, los calcimiméticos también parece que podrían atenuar la progresión de la calcificación CV en pacientes en diálisis. Mientras se desarrollan nuevas estrategias terapéuticas (p. ej. vitamina K, SNF472…), proponemos que la valoración de las calcificaciones CV puede ser una herramienta usada por el nefrólogo para la toma individualizada de decisiones terapéuticas (AU)

Cardiovascular (CV) calcification is a highly prevalent condition at all stages of chronic kidney disease (CKD) and is directly associated with increased CV and global morbidity and mortality. In the first part of this review, we have shown that CV calcifications represent an important part of the CKD-MBD complex and are a superior predictor of clinical outcomes in our patients. However, it is also necessary to demonstrate that CV calcification is a modifiable risk factor including the possibility of decreasing (or at least not aggravating) its progression with iatrogenic manoeuvres. Although, strictly speaking, only circumstantial evidence is available, it is known that certain drugs may modify the progression of CV calcifications, even though a direct causal link with improved survival has not been demonstrated. For example, non-calcium-based phosphate binders demonstrated the ability to attenuate the progression of CV calcification compared with the liberal use of calcium-based phosphate binders in several randomised clinical trials. Moreover, although only in experimental conditions, selective activators of the vitamin D receptor seem to have a wider therapeutic margin against CV calcification. Finally, calcimimetics seem to attenuate the progression of CV calcification in dialysis patients. While new therapeutic strategies are being developed (i.e. vitamin K, SNF472, etc.), we suggest that the evaluation of CV calcifications could be a diagnostic tool used by nephrologists to personalise their therapeutic decisions (AU)

Cardiovascular calcifications in chronic kidney disease: Potential therapeutic implications. / Calcificaciones cardiovasculares en la enfermedad renal crónica: Potenciales implicaciones terapéuticas.

Cardiovascular (CV) calcification is a highly prevalent condition at all stages of chronic kidney disease (CKD) and is directly associated with increased CV and global morbidity and mortality. In the first part of this review, we have shown that CV calcifications represent an important part of the CKD-MBD complex and are a superior predictor of clinical outcomes in our patients. However, it is also necessary to demonstrate that CV calcification is a modifiable risk factor including the possibility of decreasing (or at least not aggravating) its progression with iatrogenic manoeuvres. Although, strictly speaking, only circumstantial evidence is available, it is known that certain drugs may modify the progression of CV calcifications, even though a direct causal link with improved survival has not been demonstrated. For example, non-calcium-based phosphate binders demonstrated the ability to attenuate the progression of CV calcification compared with the liberal use of calcium-based phosphate binders in several randomised clinical trials. Moreover, although only in experimental conditions, selective activators of the vitamin D receptor seem to have a wider therapeutic margin against CV calcification. Finally, calcimimetics seem to attenuate the progression of CV calcification in dialysis patients. While new therapeutic strategies are being developed (i.e. vitamin K, SNF472, etc.), we suggest that the evaluation of CV calcifications could be a diagnostic tool used by nephrologists to personalise their therapeutic decisions.

Detection of cardiovascular calcifications: Is it a useful tool for nephrologists? / Detección de las calcificaciones cardiovasculares: ¿una herramienta útil para el nefrólogo?

Chronic kidney disease (CKD) has been used as a model and source of knowledge concerning the mechanisms, clinical relevance and accelerated progression of cardiovascular (CV) calcification, as well as its consequences in clinical practice, despite we know that it is a late secondary ossification phenomenon and only circumstantial evidence is available. In this comprehensive review, we firstly describe the types of CV calcification which affect CKD patients, and we analyse how its presence is directly associated with CV events and increased mortality in these patients. We also justify the use of CV calcification assessment in regular nephrology clinical practice, because CV calcification is an important predictor of clinical outcome in these patients. Consequently, we believe that CV calcification assessment is a tool that could and should be used by nephrologists when making a decision concerning individual patients, consistent with the current trend of an ever-more-personalised therapeutic approach.