Current Osteoporosis Reports最新文献

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.

Purpose of review: The impact of nephrolithiasis on skeletal growth and bone health across the life span of kidney stone formers is reviewed.

Main findings: Bone disease is an early event among kidney stone formers (SF), with distinct phenotypes according to each age, sex, menopausal status, dietary, hormonal and genetic factors. Nephrolithiasis-associated bone disorder is characterized by reduced bone mineral density (BMD) and histologically discloses low bone formation, high bone resorption and abnormal mineralization. Although hypercalciuria has been presumed to be pathogenic for bone loss in SF, the association of BMD with urinary calcium is not uniform in all studies. Hypocitraturia, metabolic disturbances, cytokines and receptors, growth factors and acid-base status may all influence skeletal outcomes. The potential link of bone disease with vascular calcification and cardiovascular disease among SF is discussed. The unique vulnerability of the younger skeleton to the effects of nephrolithiasis on attainment of peak bone mass and strength is highlighted and the association of bone loss with kidney stone formation early in life indicate the opportunity for intervention to reduce the risk of future bone fractures.

Purpose of review: Traditional Chinese Medicine has a unique system to diagnose and treat bone diseases with symptoms similar to those of osteoporosis. Sambucus williamsii Hance (SWH), a folk medicine in northern part of China for fractures healing and pain alleviation, has been demonstrated to exert bone anabolic effects in ovariectomized (OVX) rat and mice models in our previous studies. Lignans were identified to be the main bioactive fractions of SWH. However, pharmacokinetics study showed that the levels of lignan were too low to be detected in rat serum even upon taking 15 times of the effective dose of lignan-rich fraction from SWH. We hypothesize that lignans from SWH might exert its bone protective effect via the gut microbiome.

Recent findings: Our study revealed that the lignan-rich fraction of SWH did not influence the diversity of gut microbiota in OVX rats, but significantly increased the abundance of a few phyla, in particular, the restoration of the abundance of several genera that was directly correlated with bone mineral density (BMD). In addition, a subsequent metabolomic study indicated that serotonin, a neurotransmitter synthesized in the intestine and influenced by gut microbiota, may be involved in mediating the bone protective action of the lignans. Gut-derived serotonin is thought to inhibit bone growth. Based on this finding, several inhibitors that suppressed the synthesis of serotonin were identified from the lignans of SWH. Our studies suggested that microbiome is an indispensable factor for lignans derived from S. willimasii to exert bone beneficial effects.

Purpose of review: Air pollution has been raised as a novel risk factor for osteoporosis, which impose a huge burden on both individuals and society. Thus, summarizing and discussing previous results on the association between ambient air pollution and osteoporosis can be informative in synthesizing the current evidence and improving relevant action plans.

Recent findings: Recent studies reported that long-term exposure to ambient air pollution is associated with an increased risk of osteoporosis and related outcomes; however, the studied populations, air pollutants, areas, and results on high-risk populations are heterogeneous. Among air pollutants, long-term exposure to PM_2.5 showed an association with osteoporosis or osteoporosis-related fracture in general. Recent scientific evidence indicates that ambient air pollution is a potential risk factor for osteoporosis and related outcomes. Further research is warranted on how air pollution impacts these outcomes including for high-risk populations with consistent effect modifiers, and analytic methodologies.

Purpose of the review: The purpose of this Review was to summarize the evidence on the associations among estrogen status, cellular senescence, the gut microbiome and osteoporosis.

Recent findings: Indicate that osteoporosis is a global public health problem that impacts individuals and society. In postmenopausal women, a decrease in estrogen levels is associated with a decrease in gut microbial diversity and richness, as well as increased permeability of the gut barrier, which allows for low-grade inflammation. The direct effects of estrogen status on the association between bone and the gut microbiome were observed in untreated and treated ovariectomized women. In addition to the direct effects of estrogens on bone remodeling, estrogen therapy could reduce the risk of postmenopausal osteoporosis by preventing increased gut epithelial permeability, bacterial translocation and inflammaging. However, in studies comparing the gut microbiota of older women, there were no changes at the phylum level, suggesting that age-related comorbidities may have a greater impact on changes in the gut microbiota than menopausal status does. Estrogens modify bone health not only by directly influencing bone remodeling, but also indirectly by influencing the gut microbiota, gut barrier function and the resulting changes in immune system reactivity.

Purpose of review: Once prostate cancer (PCa) bone metastases develop, the prognosis dramatically declines. The precise mechanisms regulating bone metastasis remain elusive. This review will explore recent findings related to cytokines and chemokines in the process of bone metastases.

Recent findings: We discuss the role of cytokines in tumor growth, invasion, bone remodelling and angiogenesis and immune regulation in PCa skeletal metastases. Major advances in our understanding focus on immune evasion, immune checkpoint blockade, tumor-associated macrophages (TAMs), CAR-T cells, cytokine regulation of matrix metalloproteinases, cytokines including IL-10, IL-27, Interferon-γ, prostate transmembrane protein androgen induced 1 (Pmepa1), and regulation of RUNX2 transcription in supporting survival and growth of disseminated tumor cells (DTCs) and metastases development. The review highlights the complexity of cytokine actions in PCa bone metastases, suggesting potential therapeutic targets to disrupt interactions between cancer cells and their microenvironment.

Purpose of review: Sarcopenia, generally characterized by the age-related reduction in muscle strength, lean/muscle mass and functional ability, is also associated with reduced bone mass and strength and impaired brain health and function. One potential intervention which has received much 'hype' over the past few decades to countermeasure these negative consequences of biological aging is creatine monohydrate supplementation.

Recent findings: From a skeletal muscle perspective, the combination of creatine monohydrate supplementation and resistance training provides 'hope' for older adults as it improves measures of lean mass, regional (limb) muscle thickness, upper- and lower-body muscle strength and functional ability. Further, there is some evidence that creatine (supplementation or habitual diet) provides a ray of 'hope' for improving some aspects of cognitive function. The majority of research suggests that creatine is more 'hype' than 'hope' for improving measures of bone mass in older adults. Creatine monohydrate supplementation provides some anti-sarcopenic benefits for older adults.

Purpose of review: This comprehensive review discusses the complex relationship between Alzheimer's disease (AD) and osteoporosis, two conditions that are prevalent in the aging population and result in adverse complications on quality of life. The purpose of this review is to succinctly elucidate the many commonalities between the two conditions, including shared pathways, inflammatory and oxidative mechanisms, and hormonal deficiencies.

Recent findings: AD and osteoporosis share many aspects of their respective disease-defining pathophysiology. These commonalities include amyloid beta deposition, the Wnt/β-catenin signaling pathway, and estrogen deficiency. The shared mechanisms and risk factors associated with AD and osteoporosis result in a large percentage of patients that develop both diseases. Previous literature has established that the progression of AD increases the risk of sustaining a fracture. Recent findings demonstrate that the reverse may also be true, suggesting that a fracture early in the life course can predispose one to developing AD due to the activation of these shared mechanisms. The discovery of these commonalities further guides the development of novel therapeutics in which both conditions are targeted. This detailed review delves into the commonalities between AD and osteoporosis to uncover the shared players that bring these two seemingly unrelated conditions together. The discussion throughout this review ultimately posits that the occurrence of fractures and the mechanism behind fracture healing can predispose one to developing AD later on in life, similar to how AD patients are at an increased risk of developing fractures. By focusing on the shared mechanisms between AD and osteoporosis, one can better understand the conditions individually and as a unit, thus informing therapeutic approaches and further research. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.