Current Osteoporosis Reports最新文献

Purpose of review: This review aims to summarise recent evidence on the effects of dietary patterns on the risk of bone fractures and sarcopenia.

Recent findings: Several dietary patterns have been investigated in relation to musculoskeletal health, including Mediterranean Dietary Patterns (MDP), Dietary Inflammatory Indices, vegetarian and vegan diets. Adherence to 'healthier' dietary patterns appears to be protective against fractures and sarcopenia, with the strongest protective associations found between the MDP and fractures. Individuals following vegan or vegetarian eating patterns need to be aware of calcium and vitamin D requirements to maintain musculoskeletal health. Although more healthy dietary patterns may be protective for musculoskeletal health the current evidence base is limited by variation in the construction of dietary pattern scores and reported outcome measures. Future research should fully report scoring methods, intakes of dietary components across scoring groups or categories, and consider outcome measures that allow for better comparison between studies.

Purpose of review: The purpose of this review is to summarize the current understanding of cell-autonomous innate immune pathways that contribute to bone homeostasis and disease.

Recent findings: Germ-line encoded pattern recognition receptors (PRRs) are the first line of defense against danger and infections. In the bone microenvironment, PRRs and downstream signaling pathways, that mount immune defense, interface intimately with the core cellular processes in bone cells to alter bone formation and resorption. The role of PRR engagement on bone remodeling has been best described as a result of activated macrophages secreting effector molecules that reshape the characteristics of bone-resident cells. However, it is being increasingly recognized that local bone resident-cells like osteoclasts and osteoblasts possess an arsenal of PRRs. The engagement of these PRRs by stimuli in the bone niche can drive cell-autonomous (aka cell-intrinsic) responses that, in turn, impact bone-remodeling dramatically, irrespective of immune cell effectors. Indeed, this vital role for cell-autonomous innate immune responses is evident in how reduced PRR activity within osteoclast progenitors correlates with their reduced differentiation and abnormal bone remodeling. Further, cell-intrinsic PRR activity has now been shown to influence the behavior of osteoblasts, osteocytes and other local immune/non-immune cell populations. However, distinct PRR families have varying impact on bone homeostasis and inflammation, emphasizing the importance of investigating these different nodes of innate immune signaling in bone cells to better identify how they synergistically and/or antagonistically regulate bone remodeling in the course of an immune response. Innate immune sensing within bone resident cells is a critical determinant for bone remodeling in health and disease.

Purpose of review: To present race and ethnicity as evidence of the need for precision medicine in renal osteodystrophy.

Recent findings: Previously described racial-ethnic differences in bone persist in recent data on fracture risk in the healthy and CKD populations. These differences have historically been noted between Black and White participants, but recent data suggests racial-ethnic differences in bone are more intricate than previously recognized. A reflection on skeletal differences within the general, non-CKD population, provides a context to better understand skeletal differences by race within CKD. Despite numerous studies demonstrating racial differences in skeletal microarchitecture, fracture risk and skeletal biomarkers, further evidence is needed to pinpoint the etiology of racial differences and to allow precision treatment that reflects the individual patient, regardless of race. In the end, race is currently our most saliant example of the need for a precision medicine approach to the treatment of renal osteodystrophy.

Purpose of review: To describe the diagnosis, classification, and modern management of lateral compression fragility fractures of the pelvis.

Recent findings: Practice patterns are shifting toward early operative treatment of fragility fractures of the pelvis among patients who are unable to mobilize or whose injuries demonstrate occult instability on stress imaging. Early internal fixation appears to decrease pain, facilitate mobilization, accelerate hospital discharge, and minimize morbidity in this population. Lateral compression pelvic ring injuries are the most common type of fragility fracture of the pelvis. Similar to fragility fractures of the hip, lateral compression fragility fractures of the pelvis are typically sustained in a ground level fall. These injuries are associated with long acute hospital and post-acute facility admissions, loss of physical function, loss of independence, mortality, anxiety, sleep disturbance, and caregiver burnout. Unlike hip fractures, for which urgent operative treatment and early mobilization reduce mortality, lateral compression fragility fractures of the pelvis are commonly treated without surgery. Recommendations for nonoperative management of these injuries in older adults may be inappropriately generalized from studies of younger patient populations with high-energy mechanisms of pelvis fracture. However, strong evidence to support early internal fixation of these injuries practice is lacking. High quality investigations of early surgical intervention for lateral compression fragility fractures of the pelvis are needed to guide care for these patients.

Purpose of review: Bone homeostasis is balanced between formation and resorption activities and remain in relative equilibrium. Under disease states this process is disrupted, favoring more resorption over formation, leading to significant bone loss and fracture incidence. This aspect is a hallmark for patients with chronic kidney disease mineral and bone disorder (CKD-MBD) affecting a significant portion of the population, both in the United States and worldwide. Further study into the underlying effects of the uremic microenvironment within bone during CKD-MBD are critical as fracture incidence in this patient population not only leads to increased morbidity, but also increased mortality. Lack of bone homeostasis also leads to mineral imbalance contributing to cardiovascular calcifications. One area understudied is the possible involvement of bone marrow adipose tissue (BMAT) during the progression of CKD-MBD.

Recent findings: BMAT accumulation is found during aging and in several disease states, some of which overlap as CKD etiologies. Importantly, research has found presence of BMAT inversely correlates with bone density and volume. Understanding the underlying molecular mechanisms for BMAT formation and accumulation during CKD-MBD may offer a potential therapeutic avenue to improve bone homeostasis and ultimately mineral metabolism.

Purpose of review: Osteoporosis affects 50% of women and 20% of men after the age of 50. Fractures are associated with significant morbidity, increased mortality and altered quality of life. Lifestyle measures for fragility fracture prevention include good nutrition including adequate protein and calcium intakes, vitamin D sufficiency, and regular weight bearing physical exercise.

Recent findings: Dietary protein is one of the most important nutritional considerations as it affects bone mineral density, trabecular and cortical microstructure, and bone strength. When calcium intake is sufficient, higher dietary protein intake is associated with lower risk of fracture. Dairy products are a valuable source of calcium and high quality protein. Dairy product consumption, particularly fermented dairy products, are associated with a lower risk of hip fracture and vegan diets are associated with increased fracture risk. Other dietary factors associated with reduced fracture risk include at least 5 servings per day of fruits and vegetables, regular tea drinking, adherence to a Mediterranean diet and other dietary patterns which provide fibers, polyphenols and fermented dairy products. Such dietary patterns may confer health benefits through their effect on gut microbiota composition and/or function. A balanced diet including minerals, protein, fruits and vegetables is an important element in the prevention of osteoporosis and of fragility fracture.

Purpose of review: This review aims to consolidate recent observations regarding extra-osseous roles of the RANK-RANKL-OPG axis, primarily within skeletal muscle.

Recent findings: Preclinical efforts to decipher a common signalling pathway that links the synchronous decline in bone and muscle health in ageing and disease disclosed a potential role of the RANK-RANKL-OPG axis in skeletal muscle. Evidence suggests RANKL inhibition benefits skeletal muscle function, mass, fibre-type switching, calcium homeostasis and reduces fall incidence. However, there still exists ambiguity regarding the exact mechanistic actions and subsequent functional improvements. Other potential RANK-RANKL-OPG extra-osseous roles include regulation of neural-inflammation and glucose metabolism. Growing evidence suggests the RANK-RANKL-OPG axis may play a regulatory role in extra-osseous tissues, especially in skeletal muscle. Targeting RANKL may be a novel therapy in ameliorating loss of muscle mass and function. More research is warranted to determine the causality of the RANK-RANKL-OPG axis in extra-osseous tissues, especially those affected by aging.

Purpose of review: The purpose of this review is to provide a background of osteoporosis and air pollution, discussing increasing incidence of the disease with exposure to pollutants and the role that inflammation may play in this process.

Recent findings: Osteoporosis-related fractures are one of the most pressing challenges for the ageing global population, with significant increases in mortality known to occur after major osteoporotic fractures in the elderly population. Recent studies have established a firm correlative link between areas of high air pollution and increased risk of osteoporosis, particularly alarming given the increasingly urban global population. While the culprit pollutants and molecular mechanisms underlying this phenomenon have not yet been elucidated, initial studies suggest a role for inflammatory cascades in this phenomenon. While much more research is required to identify the most damaging air pollutants and to delineate the specific inflammatory molecular mechanisms, it is clear from the literature that shedding light on these pathways would unveil potential therapeutic targets to treat bone diseases, including osteoporosis. Major deficiencies of current animal models highlight the need for complex human in vitro models such as organ-on-a-chip technology to better understand the impact of air pollution.

How will the scientific community and authoritative bodies define future nutritional requirements for vitamin D? At the International Symposium on Nutritional Aspects of Musculoskeletal Health, the authors debated the strength of current evidence for setting vitamin D intake recommendations from diet: the positive side of the strength of the evidence (PRO) suggests there is a physiological requirement for vitamin D and the opposing view (CON) that in light of negative results from large, recent trials, particularly those with fractures and bone health outcomes, we are left rudderless. Should we provide recommendations based on empiric treatment of vitamin D for most groups and conditions? It is becoming increasingly evident that vitamin D plays a role in many physiological functions and processes associated with long-term human health; however, to what extent are these benefits apparent beyond what is needed for adequate nutritional status, measured as serum 25-hydroxyvitamin D levels, for active calcium absorption? The meeting attendees voted for the PRO vs. CON position at the end of the session.

Purpose of review: 3D cone beam imaging (CBCT) has allowed clinicians to better understand the anatomical variations of cranial anatomy. One crucial aspect of this technology plays is the understanding of alveolar bone morphology and remodeling. Variations in cortical bone thickness between individuals have been reported. No published study has analyzed the relationship between cortical bone thickness and rate of tooth movement. The aim of this study is to begin answering the question: is there an association between rate of tooth movement and cortical bone thickness?

Recent findings: Twenty-three patients underwent extraction of a single premolar in each of the four quadrants prior to orthodontic therapy. Routine clinical records including 3D CBCT images were acquired of all patients prior to first premolar extractions. Rate of tooth movement in each quadrant for each patient was determined via mesiodistal millimetric measurements obtained by a single calibrated operator. With CBCT images, cortical bone thickness was measured at various levels from the alveolar crest along the long axis of the to-be-extracted first premolars. The association between cortical bone thickness and rate of tooth movement was analyzed. Statistically significant associations were found between rate of tooth movement and cortical bone thickness at levels 2 mm, 5 mm, and 8 mm, apical to the alveolar crest in both the right and left maxillary quadrants (p < 0.05). Statistically significant associations were found between rate of tooth movement and cortical bone thickness at levels 5 mm and 8 mm apical to the alveolar crest in both mandibular quadrants (p < 0.05). Increased cortical bone thickness was associated with decreased rate of tooth movement. There was no statistically significant association between rate of tooth movement and cortical bone thickness 2 mm apical to the alveolar crest of the to-be-extracted first premolars in the mandibular left nor right quadrants (p > 0.05). Results suggest an inverse relationship may exist between cortical bone thickness and rate of tooth movement in both the maxilla and mandible. Cortical bone thickness may have the potential to serve as a predictive tool for rate of orthodontic tooth movement.