Low Lean Mass Predicts Incident Fractures Independently From FRAX: a Prospective Cohort Study of Recent Retirees

Muscle parameters in fragility fracture risk prediction in older adults: A scoping review

Half of osteoporotic fractures occur in patients with normal/osteopenic bone density or at intermediate or low estimated risk. Muscle measures have been shown to contribute to fracture risk independently of bone mineral density. The objectives were to review the measurements of muscle health (muscle mass/quantity/quality, strength and function) and their association with incident fragility fractures and to summarize their use in clinical practice. This scoping review follows the PRISMA-ScR guidelines for reporting. Our search strategy covered the three overreaching concepts of 'fragility fractures', 'muscle health assessment' and 'risk'. We retrieved 14 745 references from Medline Ovid SP, EMBASE, Web of Science Core Collection and Google Scholar. We included original and prospective studies on community-dwelling adults aged over 50 years that analysed an association between at least one muscle parameter and incident fragility fractures. We systematically extracted 17 items from each study, including methodology, general characteristics and results. Data were summarized in tables and graphically presented in adjusted forest plots. Sixty-seven articles fulfilled the inclusion criteria. In total, we studied 60 muscle parameters or indexes and 322 fracture risk ratios over 2.8 million person-years (MPY). The median (interquartile range) sample size was 1642 (921-5756), age 69.2 (63.5-73.6) years, follow-up 10.0 (4.4-12.0) years and number of incident fragility fractures 166 (88-277). A lower muscle mass was positively/not/negatively associated with incident fragility fracture in 28 (2.0), 64 (2.5) and 10 (0.2 MPY) analyses. A lower muscle strength was positively/not/negatively associated with fractures in 53 (1.3), 57 (1.7 MPY) and 0 analyses. A lower muscle function was positively/not/negatively associated in 63 (1.9), 45 (1.0 MPY) and 0 analyses. An in-depth analysis shows how each single muscle parameter was associated with each fragility fractures subtype. This review summarizes markers of muscle health and their association with fragility fractures. Measures of muscle strength and function appeared to perform better for fracture risk prediction. Of these, hand grip strength and gait speed are likely to be the most practical measures for inclusion in clinical practice, as in the evaluation of sarcopenia or in further fracture risk assessment scores. Measures of muscle mass did not appear to predict fragility fractures and might benefit from further research, on D3-creatine dilution test, lean mass indexes and artificial intelligence methods.

Opportunistic Muscle Evaluation During Chest CT Is Associated With Vertebral Compression Fractures in Old Adults: A Longitudinal Study

BACKGROUND

Sarcopenia and bone loss are both common in older individuals. However, the association between sarcopenia and bone fractures has not been evaluated longitudinally. In this study, we evaluated the association between computed tomography (CT)-based erector spinae muscle area and attenuation and vertebral compression fracture (VCF) in elderly individuals in a longitudinal study.

METHODS

This study recruited individuals 50 years of age and older, who did not have VCF and underwent CT imaging for lung cancer screening during January 2016 to December 2019. Participants were followed up annually until January 2021. Muscle CT value and muscle area of the erector spinae were determined for muscle assessment. Genant score was used to define new-onset VCF. Cox proportional hazards models were used to assess the association between muscle area/attenuation and VCF.

RESULTS

Of the 7 906 included participants, 72 developed new VCF over a median follow-up of 2 years. Large area of the erector spinae (adjusted hazard ratio [HR] = 0.2, 95% confidence interval [CI]: 0.1-0.7) and high bone attenuation (adjusted HR = 0.2, 95% CI: 0.1-0.5) were independently associated with VCF. High muscle attenuation was associated with severe VCF (adjusted HR = 0.46, 95% CI: 0.24-0.86). The addition of muscle area improved the area under the curve of bone attenuation from 0.79 (95% CI: 0.74-0.86) to 0.86 (95% CI: 0.82-0.91; p = .001).

CONCLUSIONS

CT-based muscle area/attenuation of the erector spinae was associated with VCF in elderly individuals, independently of bone attenuation. The addition of muscle area improved the performance of bone attenuation in predicting VCF.

Fracture risk prediction in old Chinese people-a narrative review

With aging, the burden of osteoporotic fracture (OF) increases substantially, while China is expected to carry the greatest part in the future. The risk of fracture varies greatly across racial groups and geographic regions, and systematically organized evidence on the potential predictors for fracture risk is needed for Chinese. This review briefly introduces the epidemiology of OF and expands on the predictors and predictive tools for the risk of OF, as well as the challenges for their potential translation in the old Chinese population. There are regional differences of fracture incidence among China. The fracture incidences in Hong Kong and Taiwan have decreased in recent years, while it is still increasing in mainland China. Although the application of dual-energy X-ray absorptiometry (DXA) is limited among old Chinese in the mainland, bone mineral density (BMD) by DXA has a predictive value similar to that worldwide. Other non-DXA modalities, especially heel QUS, are helpful in assessing bone health. The fracture risk assessment tool (FRAX) has a good discrimination ability for OFs, especially the FRAX with BMD. And some clinical factors have added value to FRAX, which has been verified in old Chinese. In addition, although the application of the osteoporosis self-assessment tool for Asians (OSTA) in Chinese needs further validation, it may help identify high-risk populations in areas with limited resources. Moreover, the translation use of the muscle quality and genetic or serum biomarkers in fracture prediction needs further works. More applicable and targeted fracture risk predictors and tools are still needed for the old Chinese population.

Muscle strength and physical performance contribute to and improve fracture risk prediction in older people: A narrative review

Osteoporotic fractures present a major health problem with an increasing prevalence in older people. Fractures are associated with premature mortality, reduced quality of life, subsequent fracture, and increased costs. Hence, it is crucial to identify those at higher risk of fracture. Fracture risk assessment tools incorporated clinical risk factors to improve fracture predictive power over BMD alone. However, fracture risk prediction using these algorithms remains suboptimal, warranting further improvement. Muscle strength and physical performance measurements have been associated with fracture risk. In contrast, the contribution of sarcopenia, the composite condition of low muscle mass, muscle strength and/or physical performance, to fracture risk is unclear. It is uncertain whether this is due to the problematic definition of sarcopenia per se or limitations of the diagnostic tools and cut-off points of the muscle mass component. The recent position statement from the Sarcopenia Definition and Outcomes Consortium confirmed the inclusion of muscle strength and performance in the definition of sarcopenia but not DXA-assessed lean mass. Therefore, clinicians should focus on functional assessment (muscle strength and performance) rather than muscle mass, at least as assessed by DXA, as predictors of fractures. Muscle strength and performance are modifiable risk factors. Resistance exercise improves muscle parameters in the elderly, potentially leading to reduced risk of falls and fractures in the general population and in those who sustained a fracture. Therapists may consider exercise intervention to improve muscle parameters and potentially reduce the risk of fractures. The aim of this review was to explore 1) the contribution of muscle parameters (i.e., muscle mass, strength, and physical performance) to fracture risk in older adults, and 2) the added predictive accuracy of these parameters beyond the existing fracture assessment tools. These topics provide the rationale for investigating strength and physical performance interventions to reduce fracture risk. Most of the included publications showed that muscle mass is not a good predictor of fracture risk, while poor muscle strength and performance are associated with an increased risk of fracture, particularly in men, independent of age, BMD, and other risk factors for fractures. Muscle strength and performance can potentially improve the predictive accuracy in men beyond that obtained by the fracture risk assessment tools, Garvan FRC and FRAX.

Development of a personalized fall rate prediction model in community-dwelling older adults: a negative binomial regression modelling approach

BACKGROUND

Around a third of adults aged 65 and older fall every year, resulting in unintentional injuries in 30% of the cases. Fractures are a frequent consequence of falls, primarily caused in individuals with decreased bone strength who are unable to cushion their falls. Accordingly, an individual's number of experienced falls has a direct influence on fracture risk. The aim of this study was the development of a statistical model to predict future fall rates using personalized risk predictors.

METHODS

In the prospective cohort GERICO, several fall risk factor variables were collected in community-dwelling older adults at two time-points four years apart (T1 and T2). Participants were asked how many falls they experienced during 12 months prior to the examinations. Rate ratios for the number of reported falls at T2 were computed for age, sex, reported fall number at T1, physical performance tests, physical activity level, comorbidity and medication number with negative binomial regression models.

RESULTS

The analysis included 604 participants (male: 122, female: 482) with a median age of 67.90 years at T1. The mean number of falls per person was 1.04 and 0.70 at T1 and T2. The number of reported falls at T1 as a factor variable was the strongest risk factor with an unadjusted rate ratio [RR] of 2.60 for 3 falls (95% confidence interval [CI] 1.54 to 4.37), RR of 2.63 (95% CI 1.06 to 6.54) for 4 falls, and RR of 10.19 (95% CI 6.25 to 16.60) for 5 and more falls, when compared to 0 falls. The cross-validated prediction error was comparable for the global model including all candidate variables and the univariable model including prior fall numbers at T1 as the only predictor.

CONCLUSION

In the GERICO cohort, the prior fall number as single predictor information for a personalized fall rate is as good as when including further available fall risk factors. Specifically, individuals who have experienced three and more falls are expected to fall multiple times again.

TRIAL REGISTRATION

ISRCTN11865958, 13/07/2016, retrospectively registered.

Reambulation following hindlimb unloading attenuates disuse-induced changes in murine fracture healing

Patients with bone and muscle loss from prolonged disuse have higher risk of falls and subsequent fragility fractures. In addition, fracture patients with continued disuse and/or delayed physical rehabilitation have worse clinical outcomes compared to individuals with immediate weight-bearing activity following diaphyseal fracture. However, the effects of prior disuse followed by physical reambulation on fracture healing cellular processes and adjacent bone and skeletal muscle recovery post-injury remains poorly defined. To bridge this knowledge gap and inform future treatment and rehabilitation strategies for fractures, a preclinical model of fracture healing with a history of prior unloading with and without reambulation was employed. First, skeletally mature male and female C57BL/6J mice (18 weeks) underwent hindlimb unloading by tail suspension (HLU) for 3 weeks to induce significant bone and muscle loss modeling enhanced bone fragility. Next, mice had their right femur fractured by open surgical dissection (stabilized with 24-gauge pin). The, mice were randomly assigned to continued HLU or allowed normal weight-bearing reambulation (HLU + R). Mice given normal cage activity throughout the experiment served as healthy age-matched controls. All mice were sacrificed 4-days (DPF4) or 14-days (DPF14) following fracture to assess healing and uninjured hindlimb musculoskeletal properties (6-10 mice per treatment/biological sex). We found that continued disuse following fracture lead to severely diminished uninjured hindlimb skeletal muscle mass (gastrocnemius and soleus) and femoral bone volume adjacent to the fracture site compared to healthy age-matched controls across mouse sexes. Furthermore, HLU led to significantly decreased periosteal expansion (DPF4) and osteochondral tissue formation by DPF14, and trends in increased osteoclastogenesis (DPF14) and decreased woven bone vascular area (DPF14). In contrast, immediate reambulation for 2 weeks after fracture, even following a period of prolonged disuse, was able to increase hindlimb skeletal tissue mass and increase osteochondral tissue formation, albeit not to healthy control levels, in both mouse sexes. Furthermore, reambulation attenuated osteoclast formation seen in woven bone tissue undergoing disuse. Our results suggest that weight-bearing skeletal loading in both sexes immediately following fracture may improve callus healing and prevent further fall risk by stimulating skeletal muscle anabolism and decreasing callus resorption compared to minimal or delayed rehabilitation regimens.

Extracellular vesicles secreted from mouse muscle cells improve delayed bone repair in diabetic mice

Humoral factors that are secreted from skeletal muscles can regulate bone metabolism and contribute to muscle-bone relationships. Although extracellular vesicles (EVs) play important roles in physiological and pathophysiological processes, the roles of EVs that are secreted from skeletal muscles in bone repair have remained unclear. In the present study, we investigated the effects of the local administration of muscle cell-derived EVs on bone repair in control and streptozotocin-treated diabetic female mice. Muscle cell-derived EVs (Myo-EVs) were isolated from the conditioned medium from mouse muscle C2C12 cells by ultracentrifugation, after which Myo-EVs and gelatin hydrogel sheets were transplanted on femoral bone defect sites. The local administration of Myo-EVs significantly improved delayed bone repair that was induced by the diabetic state in mice 9 days after surgery. Moreover, this administration significantly enhanced the ratio of bone volume to tissue volume at the damaged sites 9 days after surgery in the control mice. Moreover, the local administration of Myo-EVs significantly blunted the number of Osterix-positive cells that were suppressed by the diabetic state at the damage sites after bone injury in mice. Additionally, Myo-EVs significantly blunted the mRNA levels of Osterix and alkaline phosphatase (ALP), and ALP activity was suppressed by advanced glycation end product 3 in ST2 cells that were treated with bone morphogenetic protein-2. In conclusion, we have shown for the first time that the local administration of Myo-EVs improves delayed bone repair that is induced by the diabetic state through an enhancement of osteoblastic differentiation in female mice.

Association of the modified creatinine index with muscle strength and mortality in patients undergoing hemodialysis

Background

In the updated consensus, low muscle strength overtook the role of low muscle mass, and probable sarcopenia was diagnosed once low muscle strength was detected. Whether the modified creatinine index (mCI) could identify persons with probable sarcopenia who may be at risk of adverse outcomes remains unknown. We aimed to evaluate the association of the mCI with probable sarcopenia and mortality in patients undergoing hemodialysis.

Methods

In the cross-sectional study (n = 346), univariate and multivariable logistic regression analyses were performed to study the association of mCI with probable sarcopenia. Modified Quantitative Subjective Global Assessment (MQSGA) was used to evaluate the nutritional status. The performance of the mCI value for identifying probable sarcopenia was analyzed using receiver operating characteristic (ROC) curve analysis. The appropriate cutoff points were determined using Youden’s method. In the longitudinal cohort study composed of an independent hemodialysis cohort (n = 218), cox proportional regression models were used to evaluate crude and adjusted hazard ratios and 95% confidence intervals (CIs) of death by mCI and MQSGA.

Results

Cross-sectional results showed that after adjusting for confounders, the association of mCI with low muscle strength remained significant. The area under the curve (AUC) of the mCI to predict probable sarcopenia was 0.804 (95% CI, 0.744–0.863; p < 0.001) for men and 0.787 (95% CI, 0.711–0.864; p < 0.001) for women. The optimal mCI cutoff values were 21.07 mg/kg/d for men and 19.57 mg/kg/d for women, respectively. Longitudinal results showed that compared with those in the high mCI group, subjects in the low mCI group had a higher risk of death for all causes (adjusted HR, 2.51; 95% CI, 1.16–5.41; p = 0.019). Adding the mCI significantly improved the predictive accuracy for death with an increase in C-index from 0.785 to 0.805 (p = 0.026) and improved the net reclassification index (38.6%, p = 0.021), while adding MQSGA did not.

Conclusion

The mCI is a predictor of muscle strength and survival in hemodialysis patients, and is preferable to the MQSGA for predicting death. Assessment of mCI could provide additional predictive and prognostic information to sarcopenia.

Utilizing nomograms to predict prevalent vertebral fracture risk: An analysis of dysmobility syndrome in a community-dwelling population

BACKGROUND

To determine a reliable method to predict prevalent vertebral fractures (VF) by assessing the association between dysmobility syndrome (DS) and VF in a community-dwelling population.

METHODS

This cross-sectional study enrolled 518 participants from fracture-prevention educational activities held in multiple communities in Taiwan. Assessments included questionnaires, fracture risk assessment tool (FRAX), bone mineral density (BMD) and body composition using dual-energy x-ray absorptiometry (DXA), lateral thoracolumbar spine x-rays (specifically T8-S1), grip strength (GS), walking speed, and fall history.

RESULTS

DS was noted in 257 participants (49.6%) and VF was identified in 196 participants (37.8%). A higher prevalence of VF was noted in those with DS. The prevalence of VF was significantly associated with age, gender, FRAX both with and without BMD, osteoporosis, low GS, and DS. In multivariate models accounting for age and sex, the c-index was greater in those with low GS plus osteoporosis as compared to DS alone. Low GS, osteoporosis, and pre-BMD FRAX all had similar c-indexes. Pre-BMD FRAX plus low GS and osteoporosis was superior in predicting VF compared to pre-BMD FRAX plus low GS or osteoporosis alone. Besides the inclusion of age and gender, the nomogram with pre-BMD FRAX major osteoporosis fracture probability (MOF) plus low GS had improved correlation between the estimated and actual VF probability than those with pre-BMD FRAX MOF plus osteoporosis.

CONCLUSIONS

The constructed nomogram containing pre-BMD FRAX MOF plus low GS may be considered as a first-line prevalent VF screening method. Those with high-risk scores should subsequently undergo vertebral radiography and/or BMD.

A pooled analysis of the association between sarcopenia and osteoporosis

BACKGROUND

Sarcopenia is a progressive generalized skeletal muscle disorder that causes the accelerated loss of muscle mass and function. Osteoporosis is a systemic condition of the skeleton that results in low bone mass and quality. Several studies have suggested that osteoporosis and sarcopenia are interrelated; however, a few studies indicate the lack of a significant association between sarcopenia and osteoporosis. We aimed to evaluate the association between sarcopenia and osteoporosis via a systematic review and pooled analysis.

METHODS

From the inception of the PubMed and Embase databases until September 2022, we conducted a systematic search for studies evaluating the relationship between sarcopenia and osteoporosis. Study appraisal and synthesis methods: We included observational studies that provided 95% confidence intervals (CIs) and risk estimates. Two reviewers independently extracted data and assessed the quality of the research. The random-effects model was applied to the pool analysis, and the odds ratios (ORs) and 95% CIs were finally calculated.

RESULTS

The primary statistic was the mutual risk between sarcopenia and osteoporosis. According to the inclusion criteria, 56 studies (796,914 participants) were finally included. Sarcopenia was significantly correlative to the risk of osteoporosis (OR, 3.06; 95% CI, 2.30-4.08), and each standard deviation increase in relative appendicular skeletal muscle mass was significantly related to a decreased risk of osteoporosis (OR, 0.65; 95% CI, 0.56-0.75). Osteoporosis observably referred to a higher risk of sarcopenia (OR, 2.63; 95% CI, 1.98-3.49).

CONCLUSION

Our research indicated that sarcopenia and osteoporosis are highly positively correlated. Osteoporosis is closely associated with the risk of sarcopenia. Our finding highlights the importance of sarcopenia screening for those at risk of osteoporosis, and vice versa. However, heterogeneity was noted among the studies, and this might have influenced the accuracy of the results. Therefore, the results of our study should be interpreted with caution.

Muscle strength is associated with fracture risk obtained by fracture risk assessment tool (FRAX) in women with breast cancer

Background

Women with breast cancer are at risk for the development of sarcopenia and occurrence of fractures. The initial and periodic screening of these conditions can prevent the risks of disability, poor quality of life, and death. The present study investigated the association between sarcopenia phenotypes and fracture risk, assessed by the Fracture Risk Assessment Tool (FRAX) in women with breast cancer.

Methods

Cross-sectional study. It included women aged between 40 and 80 years, diagnosed with Luminal subtype breast cancer, with time of diagnosis ≤ 12 months, who had not started endocrine therapy, did not have metastasis, had not been treated for another malignancy, and had no recurrences. Sociodemographic, habits and lifestyle, clinical, anthropometric, and body composition variables were considered. Muscle strength, skeletal muscle mass, and physical performance were investigated using handgrip strength (HGS), appendicular skeletal muscle mass index (ASMI), and Timed Up and Go test (TUGT), respectively. Fracture risk was assessed using FRAX. Multiple linear regression models were conducted to verify the association between exposure variables and sarcopenia phenotypes. A significance level of p < 0.05 was adopted for all tests using the SPPS 25.0 program.

Results

Sixty-two women with a mean age of 58.1 ± 10.4 years were evaluated. Of these, 66.1% self-declared to be non-white, 41.9% and 71.0% did not consume alcohol or smoke, respectively, and 61.3% were insufficiently active. A total of 45.2% had clinical stage II carcinoma and 65.5% had the invasive breast carcinoma histological subtype. There was a predominance of adequacy of HGS (88.7%), ASMI (94.5%), and TUGT (96.8%), as well as low risk of hip fractures (85.5%) and major fractures (82.3%). HGS remained associated with FRAX hip fractures (p = 0.007) and FRAX major fractures (p = 0.007) in the adjusted models, while ASMI was associated with body mass (p < 0.001).

Conclusions

Low muscle strength was the sarcopenia phenotype that remained associated with fracture risk in women with breast cancer, independently of sociodemographic factors, level of physical activity, and clinical factors. In addition to the assessment of probable sarcopenia, this measurement may point out the risk of fractures.

Effects of muscle quantity and bone mineral density on injury and outcomes in older adult motor vehicle crash occupants

Objectives: Quantify the independent and combined effects of abdominal muscle quantity and lumbar bone mineral density (BMD) on injury risk and in-hospital outcomes in severely injured motor vehicle crash (MVC) occupants ages 50 and older.Methods: Skeletal muscle area measurements of MVC occupants were obtained through semi-automated segmentation of an axial computed tomography (CT) slice at the L3 vertebra. An occupant height-normalized Skeletal Muscle Index (SMI) was calculated - a defining metric of sarcopenia and low muscle mass (sarcopenia thresholds: <38.5 cm2/m2 females; <52.4 cm2/m2 males). Lumbar BMD was obtained using a validated, phantomless CT calibration method (osteopenia threshold: <145 mg/cm3). SMI and BMD values were used to categorize occupants, and logistic regression was used to associate sarcopenia, osteopenia, and osteosarcopenia predictors to injury outcomes (e.g., Injury Severity Score (ISS), maximum Abbreviated Injury Scale (MAIS) score, fractures) and hospital outcomes (e.g., length of stay, ICU days).Results: Of the 336 occupants, 210 (63%) were female (mean ± SD: age 66.3 ± 10.6). SMI was 41.7 ± 8.0 cm2/m2 in females and 51.2 ± 10.8 cm2/m2 in males. Based on SMI, 40% of females and 55% of males were classified as sarcopenic. BMD was 163.2 ± 38.3 mg/cm3 in females and 164.1 ± 35.4 mg/cm3 in males, with 41% of females and 33% of males classified as osteopenic. Prevalence of both conditions (osteosarcopenia) was similar between females (21%) and males (22%). Incidence of low SMI and BMD increased with age. Sarcopenic individuals were less likely to sustain a MAIS 2+ thorax injury and had longer ICU stays. Osteopenic individuals were more likely to sustain upper extremity injuries and fractures, and were less likely to be discharged to a rehabilitation facility. Osteosarcopenic individuals were less likely to be ventilated or admitted to the ICU but tended to spend more time on the ventilator if placed on one.Conclusions: Osteosarcopenia was not associated with any injury outcomes, but sarcopenia was associated with thoracic injury and osteopenia was associated with upper extremity injury incidence. Sarcopenia was only associated with ICU length of stay, while osteopenia was only associated with discharge destination. Osteosarcopenia was associated with likelihood of being ventilated, being admitted to the ICU, and with increased length of ventilation.

Update of the fracture risk prediction tool FRAX: a systematic review of potential cohorts and analysis plan

We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures.

INTRODUCTION

The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide. The aim of this study is to determine whether the current algorithms can be further optimised with respect to current and novel risk factors.

METHODS

A computerised literature search was performed in PubMed from inception until May 17, 2019, to identify eligible cohorts for updating the FRAX coefficients. Additionally, we searched the abstracts of conference proceedings of the American Society for Bone and Mineral Research, European Calcified Tissue Society and World Congress of Osteoporosis. Prospective cohort studies with data on baseline clinical risk factors and incident fractures were eligible.

RESULTS

Of the 836 records retrieved, 53 were selected for full-text assessment after screening on title and abstract. Twelve cohorts were deemed eligible and of these, 4 novel cohorts were identified. These cohorts, together with 60 previously identified cohorts, will provide the resource for constructing an updated version of FRAX comprising 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. For each known and candidate risk factor, multivariate hazard functions for hip fracture, major osteoporotic fracture and death will be tested using extended Poisson regression. Sex- and/or ethnicity-specific differences in the weights of the risk factors will be investigated. After meta-analyses of the cohort-specific beta coefficients for each risk factor, models comprising 10-year probability of hip and major osteoporotic fracture, with or without femoral neck bone mineral density, will be computed.

CONCLUSIONS

These assembled cohorts and described models will provide the framework for an updated FRAX tool enabling enhanced assessment of fracture risk (PROSPERO (CRD42021227266)).

Risk factors for osteoporosis and fractures in rheumatoid arthritis

People with rheumatoid arthritis (RA) have both disease-specific risk factors for osteoporosis and fractures in addition to those that affect the general population. Disease specific risks include directly pathogenic auto-antibodies, chronic exposure to systemic inflammation, and joint damage causing early disability. Risk factors that affect the general population which may have a higher prevalence in RA include smoking, calcium and vitamin D deficiency as well as hypogonadism. Additionally, chronic exposure to glucocorticoids results in reduced bone mineral density and body composition changes which can further increase fracture risk. In this review we discuss these risk-factors for osteoporosis as well as factors that may impact fall and fracture risk in people with RA.

Enhanced Risk of Osteoporotic Fracture in Patients with Sarcopenia: A National Population-Based Study in Taiwan

Sarcopenia is a progressive and generalized skeletal muscle disorder associated with poor health outcomes in older adults. However, its association with the risk of fracture risk is yet to be clarified. Therefore, this study aimed to assess the incidence and consequence of osteoporosis-related fractures among patients with sarcopenia in Taiwan. A retrospective, population-based study on 616 patients with sarcopenia, aged >40 years, and 1232 individuals without sarcopenia was conducted to evaluate claims data from Taiwan’s National Health Insurance Research Database collected in the period January 2000−December 2013. The incidence rate of osteoporosis-related fracture was 18.13 and 14.61 per 1000 person years in the patients with sarcopenia and comparison cohort, respectively. Patients with sarcopenia had a greater osteoporotic fracture risk (adjusted hazard ratio [HR] 2.11; 95% confidence interval [CI] 1.47−3.04) after correcting for possible confounding. Additionally, females showed statistically significant correlations of sarcopenia with osteoporosis-related fracture risk (HR 1.53; CI 0.83−2.8 for males and HR 2.40, CI 1.51−3.81 for females). During this retrospective study on the fracture risk in Taiwan, an adverse impact of sarcopenia was observed, which substantiates the need to work toward sarcopenia prevention and interventions to reverse fracture susceptibility in patients with sarcopenia.

Myostatin Levels and the Risk of Myopenia and Rheumatoid Cachexia in Women with Rheumatoid Arthritis

Background

Myostatin is a regulator of muscle size. To date, there have been no published studies focusing on the relation between myostin levels and myopenia in rheumatoid arthritis (RA).

Objective

Evaluate the value of serum myostatin as a biomarker of cachexia and low skeletal muscle mass (LSMM) in RA patients, along with whether high serum myostatin is associated to these conditions after adjusting for potential confounders.

Methods

This cross-sectional study included 161 female RA patients and 72 female controls. In the RA group, we assessed several potential risk factors for LSMM and rheumatoid cachexia. Dual-energy X-ray absorptiometry was used to quantify the skeletal muscle mass index (SMMI) (considering LSMM ≤ 5.5 kg/m²) and the presence of rheumatoid cachexia (a fat-free mass index ≤ 10 percentile and fat mass index ≥ 25 percentile of the reference population). Serum myostatin concentrations were determined by ELISA. To identify a cut-off for high serum myostatin levels, we performed ROC curve analysis. Multivariable logistic regression analysis was used to identify the risk factors for LSMM and rheumatoid cachexia. The risk was expressed as odds ratios (ORs) and their 95% confidence intervals (95% CIs).

Results

Compared to the controls, the RA group had a higher proportion of LSMM and exhibited high serum myostatin levels (p < 0.001). ROC curve analysis showed that a myostatin level ≥ 17 ng/mL was the most efficient cut-off for identifying rheumatoid cachexia (sensitivity: 53%, specificity: 71%) and LSMM (sensitivity: 43%, specificity: 77%). In the multivariable logistic regression, RA with high myostatin levels (≥17 ng/mL) was found to increase the risk of cachexia (OR = 2.79, 95% CI: 1.24-6.29; p = 0.01) and LSMM (OR = 3.04, 95% CI: 1.17-7.89; p = 0.02).

Conclusions

High serum myostatin levels increase the risk of LSMM and rheumatoid cachexia. We propose that high myostatin levels are useful biomarkers for the identification of patients in risk of rheumatoid cachexia and myopenia.

The relationship between insulin resistance, bone mineral density, and fracture risk in postmenopausal women

Background/Aim. Skeletal muscles and bones are essential tissues that, in addition to supporting the body, are the primary site of postprandial glucose intake, which is significantly associated with insulin resistance. The aim of this study was to determine the effect of insulin resistance on bone mineral density (BMD) and fracture risk and re-evaluate the relationship between muscle properties and BMD and insulin resistance in postmenopausal women in Serbia. Methods. Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) was calculated in postmenopausal women who were divided into two groups. The ?cut-off? value of insulin resistance for the group with ?Low HOMA-IR? was < 2, and for ?High HOMA-IR? > 2. Fat mass (FM), lean mass (LM), and BMD were measured on the hip and spine using a densitometer with dual-energy X-ray absorptiometry. Results. FM and LM had an evident impact on BMD. The decrease in LM and fat buildup was associated with a higher incidence of insulin resistance. A positive correlation was confirmed between HOMA-IR and BMD on the spine and hip, but there was no correlation between insulin resistance and fracture risk. Conclusion. LM and FM have significant effects on BMD. The association between LM, FM, BMD and the onset of insulin resistance in postmenopausal women is confirmed. However, women with higher insulin resistance levels and higher BMD do not have a lower fracture risk.

The analysis of osteosarcopenia as a risk factor for fractures, mortality, and falls

Osteosarcopenia is defined as the concomitant occurrence of sarcopenia and osteoporosis/osteopenia. This study aimed to clarify whether osteosarcopenia implies a greater risk of fractures, mortality, and falls and to draw attention to osteosarcopenia.

INTRODUCTION

Osteosarcopenia, which is characterized by the co-existence of osteoporosis/osteopenia and sarcopenia, is one of the most challenging geriatric syndromes. However, the association between osteosarcopenia and the risk of falls, fractures, disability, and mortality is controversial.

METHODS

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials, from their inception to March 18, 2021, for cohort studies on the relationship between osteosarcopenia and fractures, falls, and mortality. Two reviewers independently extracted data and assessed study quality. A pooled analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) using fixed or random-effects models.

RESULTS

Eight cohort studies including 19,836 participants showed that osteosarcopenia significantly increased the risk of fracture (OR 2.46, 95% CI 1.83-3.30, P_{heterogeneity} = 0.006, I² = 63.0%), three cohort studies involving 2601 participants indicated that osteosarcopenia significantly increased the risk of mortality (OR 1.66, 95% CI 1.23-2.26, P_{heterogeneity} = 0.214, I² = 35.2%), and three cohort studies involving 3144 participants indicated that osteosarcopenia significantly increased the risk of falls (OR 1.62, 95% CI 1.28-2.04, P_{heterogeneity} = 0.219, I² = 34.1%). No publication bias existed among the studies regarding the association between osteosarcopenia and fractures. The findings were robust according to the subgroup and sensitivity analyses.

CONCLUSIONS

This pooled analysis demonstrated that osteosarcopenia significantly increased the risk of fractures, falls, and mortality, thus highlighting its relevance in daily life. Therefore, we suggest that elderly persons should be aware of the risks associated with osteosarcopenia.

RANKL-Induced Increase in Cathepsin K Levels Restricts Cortical Expansion in a Periostin-Dependent Fashion: A Potential New Mechanism of Bone Fragility

Receptor activator of nuclear factor-κΒ ligand (RANKL) is necessary and sufficient to promote osteoclastogenesis and a key pathogenic factor in osteoporosis. Failure of periosteal apposition to compensate for bone loss due to endosteal resorption further contributes to bone fragility. Whether these two processes are biologically related, however, remains unknown. Using high-resolution peripheral quantitative computed tomography (HR-pQCT), we first examined cortical bone parameters at distal radius and tibia in postmenopausal women (PMW) as well as in cadaveric human adult humeri. Increases in medullary area were negatively correlated with cortical bone volume but positively with total bone volume, and this relationship was stronger in the dominant arm, suggesting a mechanically driven process. To investigate the role of RANKL in this dual process, we used mice overexpressing huRANKL (huRANKLTg⁺ ). Trabecular and cortical bone volume (Ct.BV) are reduced in these mice, whereas cortical total volume (Ct.TV) is increased. In these bones, Sost mRNA levels are downregulated and periostin (Postn) mRNA levels upregulated, hence providing a positive message for periosteal bone formation. In turn, genetic deletion of Postn in huRANKLTg⁺  mice prevented the increase in Ct.TV and aggravated bone fragility. In contrast, cathepsin K (Ctsk) ablation improved Ct.TV in both huRANKLTg⁺  and wild-type (WT) mice and stimulated periosteal bone formation, while augmenting Postn protein levels. Therefore, bone strength in huRANKLTg⁺ /Ctsk^-/- mice was restored to WT levels. These findings suggest that high levels of RANKL not only induce endosteal bone loss but may somewhat restrict periosteal bone formation by triggering periostin degradation through cathepsin K, hence providing a biological mechanism for the observed limited increase in cortical area in postmenopausal women. © 2021 American Society for Bone and Mineral Research (ASBMR).

Sarcopenia Definitions as Predictors of Fracture Risk Independent of FRAX® , Falls, and BMD in the Osteoporotic Fractures in Men (MrOS) Study: A Meta-Analysis

Dual-energy X-ray absorptiometry (DXA)-derived appendicular lean mass/height2 (ALM/ht2 ) is the most commonly used estimate of muscle mass in the assessment of sarcopenia, but its predictive value for fracture is substantially attenuated by femoral neck (fn) bone mineral density (BMD). We investigated predictive value of 11 sarcopenia definitions for incident fracture, independent of fnBMD, fracture risk assessment tool (FRAX® ) probability, and prior falls, using an extension of Poisson regression in US, Sweden, and Hong Kong Osteoporois Fractures in Men Study (MrOS) cohorts. Definitions tested were those of Baumgartner and Delmonico (ALM/ht2 only), Morley, the International Working Group on Sarcopenia, European Working Group on Sarcopenia in Older People (EWGSOP1 and 2), Asian Working Group on Sarcopenia, Foundation for the National Institutes of Health (FNIH) 1 and 2 (using ALM/body mass index [BMI], incorporating muscle strength and/or physical performance measures plus ALM/ht2 ), and Sarcopenia Definitions and Outcomes Consortium (gait speed and grip strength). Associations were adjusted for age and time since baseline and reported as hazard ratio (HR) for first incident fracture, here major osteoporotic fracture (MOF; clinical vertebral, hip, distal forearm, proximal humerus). Further analyses adjusted additionally for FRAX-MOF probability (n = 7531; calculated ± fnBMD), prior falls (y/n), or fnBMD T-score. Results were synthesized by meta-analysis. In 5660 men in USA, 2764 Sweden and 1987 Hong Kong (mean ages 73.5, 75.4, and 72.4 years, respectively), sarcopenia prevalence ranged from 0.5% to 35%. Sarcopenia status, by all definitions except those of FNIH, was associated with incident MOF (HR = 1.39 to 2.07). Associations were robust to adjustment for prior falls or FRAX probability (without fnBMD); adjustment for fnBMD T-score attenuated associations. EWGSOP2 severe sarcopenia (incorporating chair stand time, gait speed, and grip strength plus ALM) was most predictive, albeit at low prevalence, and appeared only modestly influenced by inclusion of fnBMD. In conclusion, the predictive value for fracture of sarcopenia definitions based on ALM is reduced by adjustment for fnBMD but strengthened by additional inclusion of physical performance measures. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Effects of fluid flow shear stress to mouse muscle cells on the bone actions of muscle cell-derived extracellular vesicless

The interactions between skeletal muscle and bone have been recently noted, and muscle-derived humoral factors related to bone metabolism play crucial roles in the muscle/bone relationships. We previously reported that extracellular vesicles from mouse muscle C2C12 cells (Myo-EVs) suppress osteoclast formation in mice. Although mechanical stress is included in extrinsic factors which are important for both muscle and bone, the detailed roles of mechanical stress in the muscle/bone interactions have still remained unknown. In present study, we examined the effects of fluid flow shear stress (FFSS) to C2C12 cells on the physiological actions of muscle cell-derived EV. Applying FFSS to C2C12 cells significantly enhanced muscle cell-derived EV-suppressed osteoclast formation and several osteoclast-related gene levels in mouse bone marrow cells in the presence of receptor activator nuclear factor κB ligand (RANKL). Moreover, FFSS to C2C12 cells significantly enhanced muscle cell-derived EV-suppressed mitochondria biogenesis genes during osteoclast formation with RANKL treatment. In addition, FFSS to C2C12 cells significantly enhanced muscle cell-derived EV-suppressed osteoclast formation and several osteoclast-related gene levels in Raw264.7 cells in the presence of RANKL. Small RNA-seq-analysis showed that FFSS elevated the expression of miR196a-5p and miR155-5p with the suppressive actions of osteoclast formation and low expression in mouse bone cells. On the other hand, muscle cell-derived EVs with or without FFSS to C2C12 cells did not affect the expression of osteogenic genes, alkaline phosphatase activity and mineralization in mouse osteoblasts. In conclusion, we first showed that FFSS to C2C12 cells enhances the suppressive effects of muscle cell-derived EVs on osteoclast formation in mouse cells. Muscle cell-derived EVs might be partly involved in the effects of mechanical stress on the muscle/bone relationships.

Predictive Value of DXA Appendicular Lean Mass for Incident Fractures, Falls, and Mortality, Independent of Prior Falls, FRAX, and BMD: Findings from the Women's Health Initiative (WHI)

In the Women's Health Initiative (WHI), we investigated associations between baseline dual-energy X-ray absorptiometry (DXA) appendicular lean mass (ALM) and risk of incident fractures, falls, and mortality (separately for each outcome) among older postmenopausal women, accounting for bone mineral density (BMD), prior falls, and Fracture Risk Assessment Tool (FRAX® ) probability. The WHI is a prospective study of postmenopausal women undertaken at 40 US sites. We used an extension of Poisson regression to investigate the relationship between baseline ALM (corrected for height2 ) and incident fracture outcomes, presented here for major osteoporotic fracture (MOF: hip, clinical vertebral, forearm, or proximal humerus), falls, and death. Associations were adjusted for age, time since baseline and randomization group, or additionally for femoral neck (FN) BMD, prior falls, or FRAX probability (MOF without BMD) and are reported as gradient of risk (GR: hazard ratio for first incident fracture per SD increment) in ALM/height2 (GR). Data were available for 11,187 women (mean [SD] age 63.3 [7.4] years). In the base models (adjusted for age, follow-up time, and randomization group), greater ALM/height2 was associated with lower risk of incident MOF (GR = 0.88; 95% confidence interval [CI] 0.83-0.94). The association was independent of prior falls but was attenuated by FRAX probability. Adjustment for FN BMD T-score led to attenuation and inversion of the risk relationship (GR = 1.06; 95% CI 0.98-1.14). There were no associations between ALM/height2 and incident falls. However, there was a 7% to 15% increase in risk of death during follow-up for each SD greater ALM/height2 , depending on specific adjustment. In WHI, and consistent with our findings in older men (Osteoporotic Fractures in Men [MrOS] study cohorts), the predictive value of DXA-ALM for future clinical fracture is attenuated (and potentially inverted) after adjustment for femoral neck BMD T-score. However, intriguing positive, but modest, associations between ALM/height2 and mortality remain robust. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Associations between Physical Function, Bone Density, Muscle Mass and Muscle Morphology in Older Men with Sarcopenia: A Pilot Study

Background and Objectives: It is thought that muscle and bone interact only on a biomechanical level, however, some research is now emerging that links bone and muscle on a cellular level. The aim of this study was to explore associations between physical function, muscle mass and bone density in community-dwelling elderly men with sarcopenia. A secondary goal was to analyze if muscle morphology was associated with bone density and physical functioning. Materials and Methods: Body composition was measured by dual-energy X-ray absorptiometry (DXA). Bone density was evaluated according to WHO criteria. Sarcopenia was diagnosed according to European Working Group on Sarcopenia in Older People (EWGSOP) criteria: low muscle mass and low muscle strength or low physical performance. Microbiopsy of musculus vastus lateralis was performed with a disposable muscle microbiopsy system. The perimeter and cross-sectional area of muscle fibers were calculated using image analysis software in whole slide images; type of fibers and their distribution were evaluated as well. Results: A total of 151 men, 60 years or older were included in this study. Mean age of the subjects was 72.9 ± 8.02 years. Sarcopenia was diagnosed in 45 (29.8%) men. Multiple significant correlations were found between bone mineral density, lean mass, appendicular lean mass, arm and leg lean mass, gait speed, balance test and handgrip strength in sarcopenic men. Lean mass was associated with femoral neck BMD (bone mineral density; r = 0.418, p = 0.006) and handgrip strength (r = 0.553, p < 0.001). In the sarcopenia group, 25 muscle biopsies were examined. In 9 sarcopenic men with T-scores equal or below -2.5, the muscle fiber area had a significant correlation with the balance test (r = 0.73, p = 0.025). Conclusions: In men with sarcopenia, low lean muscle mass was associated with low femoral neck BMD and low muscle strength. In sarcopenic men with osteoporosis, low muscle fiber area was associated with low scores in a balance test.

Sarcopenia as a Risk Factor for Future Hip Fracture: A Meta-Analysis of Prospective Cohort Studies

OBJECTIVE

Our study aims to determine whether sarcopenia is a predictive factor of future hip fractures.

DESIGN

Systematic review and meta-analysis. Set: We searched for potentially suitable articles in PubMed, Cochrane library, Medline and EMBASE from inception to March 2020. The quality of the research was assessed by the Newcastle-Ottawa Scale (NOS). Finally, a meta-analysis was conducted with the Stata software.

PARTICIPANTS

Older community-dwelling residents.

MEASUREMENTS

Hip fracture due to sarcopenia.

RESULTS

We retrieved 2129 studies through our search strategy, and five studies with 23,359 individuals were analyzed in our pooled analyses. Sarcopenia increases the risk of future hip fractures with a pooled hazard ratio (HR) of 1.42 (95% CI: 1.18-1.71, P <0.001, I2 = 37.7%). In addition, in subgroup analyses based on different definitions of sarcopenia, sarcopenia was associated with the risk of future hip fractures with the Asian Working Group for Sarcopenia (AWGS) criteria with a pooled HR of 2.13(95% CI: 1.33-3.43). When subgroup analyses were conducted by sex, sarcopenia was associated with the risk for future hip fractures in females with pooled HRs of 1.69 (95% CI: 1.18-2.43). Sarcopenia was associated with the risk of future hip fractures in the group with a follow-up period of more than 5 years, with a pooled HR of 1.32 (95% CI: 1.08-1.61), and in the group with a follow-up period of less than 5 years, with a pooled HR of 2.13 (95% CI: 1.33-3.43).

CONCLUSIONS

Sarcopenia could significantly increase the risk of future hip fracture in old people; thus, it is necessary to prevent hip fractures in individuals with sarcopenia.

Association between sarcopenia and fall characteristics in older adults with fragility hip fracture

INTRODUCTION

Sarcopenia is known as a risk factor for falls and hip fracture, and understanding fall characteristics is important for the fall-prevention programs. The aim of this study is to investigate whether sarcopenia is associated with fall characteristics in older adults with fragility hip fracture.

METHODS

A cross-sectional study was conducted in 147 patients over 65 years of age who had undergone a two-week postoperative rehabilitation for hip fracture. Fall characteristics included the fall type, direction and location. Fall types were categorized into two groups: fragile falls, leg weakness during walking, changing positions or standing; non-fragile falls, slipping or tripping while walking. Correlations between sarcopenia and fall characteristics, and of fall type with sarcopenia and fall characteristics were analyzed. Logistic regression analyzes were used to identify independent risk factors for fragile falls.

RESULTS

Sarcopenia was significantly correlated with fragile falls (r = .222, p = .007) and was more prevalent in the fragile fall group than the non-fragile fall group (53.5% vs. 32.9%). Sarcopenia (OR = 2.354, 95% CI 1.177-4.709, p = .016), moderate comorbidities (OR = 3.572, 95% CI 1.109-11.501, p = .033) and severe comorbidities (OR = 5.396, 95% CI 1.476-19.729, p = .011) by the Charlson Comorbidity Index were significant independent risk factors for fragile falls.

CONCLUSIONS

Sarcopenia was correlated with fragile falls; moreover, it was a risk factor for all of these fall types in older adults with fragility hip fracture. Based on these associations, targeted fall-prevention programs for older adults with sarcopenia, a high risk factor of falls and fractures, could help reduce the incidence rates of falls and fragility hip fracture.

The influence of whole-body electromyostimulation training in middle-aged women

BACKGROUND: Whole-body electromyostimulation (WB-EMS) is a new tendency in training used to complement conventional training. OBJECTIVE: The aim was to analyze the effects of training with WB-EMS on body composition, strength and balance in middle-aged women. METHODS: Twenty-eight women were randomly assigned to two groups: the WB-EMS group (age = 48.1 ± 4.3 years) or the control group (CG) (age = 51.1 ± 5.4 years). All participants continued their training of 2 days⋅week-1 and 60 min⋅day-1 of endurance-dynamic strength exercises and additionally did 20 minutes more of dynamic strength exercises one day⋅week-1: the WB-EMS group did the additional training with WB-EMS and the CG did the same training but without WB-EMS. Body composition, muscle isokinetic strength of the knee flexors/extensors and postural stability were measured before and after 8 weeks of training. RESULTS: After the training program, the WB-EMS group showed lower values for the waist circumference (83.00 ± 7.37 vs. 78.50 ± 7.30 cm; p< 0.01), hip circumference (104.80 ± 8.61 vs. 101.00 ± 6.78 cm; p< 0.05) and total fat mass (37.04 ± 6.08 vs. 36.26 ± 5.78%; p< 0.05). In balance stability the WB-EMS group reduced their Fall Risk Index (1.70 ± 0.51 vs. 1.30 ± 0.38 AU; p< 0.01) and deviation (1.50 ± 0.43 vs. 1.03 ± 0.74 AU; p< 0.01) after training and showed lower values in the Fall Risk Index (p= 0.007) and deviation (p= 0.024). CONCLUSIONS: The WB-EMS training program helps reduce the risk of falling and improves body composition variables and balance results in middle-aged physically active women.

Decline in Muscle Strength and Performance Predicts Fracture Risk in Elderly Women and Men

CONTEXT

Muscle strength and performance are associated with fractures. However, the contribution of their rate of decline is unclear.

OBJECTIVE

To assess the independent contribution of the rate of decline in muscle strength and performance to fracture risk.

DESIGN, SETTING, AND PARTICIPANTS

Community-dwelling women (n = 811) and men (n = 440) aged 60 years or older from the prospective Dubbo Osteoporosis Epidemiology Study followed from 2000 to 2018 for incident fracture. Clinical data, appendicular lean mass/height2 (ht)2, bone mineral density, quadricep strength/ht (QS), timed get-up-and-go (TGUG), 5 times repeated sit-to-stand (5xSTS), and gait speed (GS) measured biennially. Rates of decline in muscle parameters were calculated using ordinary least squares regression and fracture risk was assessed using Cox's models.

MAIN OUTCOME

Incident low-trauma fracture ascertained by x-ray report.

RESULTS

Apart from lean mass in women, all muscle parameters declined over time. Greater rates of decline in physical performance were associated with increased fracture risk in women (Hazard ratios [HRs] ranging from 2.1 (95% CI: 1.5-2.9) for GS to 2.7 (95% CI: 1.9-3.6) for 5xSTS, while in men only the decline in GS was associated with fracture risk (HR: 3.4 [95% CI: 1.8-6.3]). Baseline performance and strength were also associated with increased fracture risk in men (HRs ranging from 1.8 (95% CI: 1.1-3.0) for QS to 2.5 (95% CI: 1.5-4.1) for TGUG, but not in women.

CONCLUSION

Rate of decline in physical performance in both genders, and baseline strength and performance in men, contributed independently to fracture risk. Sit-to-stand and GS were the tests most consistently associated with fractures. Further studies are required to determine whether muscle strength and/or performance improve the predictive accuracy of fracture prediction models.

The Predictive Value of Sarcopenia and Falls for 2-Year Major Osteoporotic Fractures in Community-Dwelling Older Adults

To evaluate the associations of sarcopenia and previous falls with 2-year major osteoporotic fractures (MOFs) in community-dwelling older adults. Four thousand Chinese men and women ≥ 65 years recruited from Hong Kong communities were prospectively followed up. Measures of muscle mass, grip strength, gait speed and falls in the previous year were recorded at baseline, the 2nd year and the 4th year visit for each subject. The associations of fall history, sarcopenia and its components with 2-year MOFs were evaluated using generalized linear mixed models. Poor grip strength and poor gait speed were significantly associated with a higher 2-year MOFs risk, with an adjusted OR (95% CI) per one SD decrease of 1.48 (1.17, 1.87) and 1.17 (1.00, 1.36), respectively. Falls in the previous year was a significant predictor for 2-year MOFs risk, with an adjusted OR (95% CI) per one added fall of 1.85 (1.40, 2.44) in men and 1.26 (1.01, 1.58) in women. The adjusted OR (95% CI) of height adjusted appendicular lean muscle mass (ALM/height²) per one SD decrease and sarcopenia for 2-year MOFs risk were 1.34 (0.87, 2.06) and 1.72 (0.92, 3.21) in men, and were 0.73 (0.57, 0.93) and 0.76 (0.39, 1.47) in women, respectively (P for interaction by gender = 0.012 and 0.017, respectively). Poor sarcopenia-related physical performance and falls in the previous year were significant predictors for 2-year MOFs in community-dwelling older adults. The predictive value of ALM by DXA for near-term fracture risk is limited and different across genders.

Risk Factors for Low Muscle Mass in a Population-based Prospective Cohort of Brazilian Community-dwelling Older Women: The São Paulo Ageing & Health (SPAH) Study

INTRODUCTION

Sarcopenia is characterized by progressive loss of skeletal muscle mass, which results in decreased muscle strength, functional impairment, and increased risk of death. Few studies have performed a concomitant evaluation of clinical, laboratory, and body composition variables to accurately determine the contribution of each parameter to low muscle mass (LMM) in older subjects. This study aimed to identify risk factors (clinical, laboratory parameters, BMD, and body composition by DXA including visceral fat) for LMM in a prospective cohort of older Brazilian women.

METHODS

A total of 408 women aged ≥65 yr from the São Paulo Ageing & Health study were evaluated with clinical data, laboratory bone tests, BMD, and body composition by DXA using Hologic QDR 4500A equipment. Risk factors were measured at baseline (2005-2007). After a follow-up of 4.3 ± 0.8 yr, subjects were classified according to the LMM definition of the Foundation for the National Institutes of Health criteria. LMM was defined when appendicular lean mass divided by body mass index was less than 0.512. Multivariate logistic regression models were used to identify independent risk factors for LMM.

RESULTS

At the end of follow-up, 116 women (28.4%) had LMM. Age averages were 73.3 ± 4.9 yr in the LMM group and 72.5 ± 4.5 yr in the normal group (p = 0.11). Mean BMI was 30.6 ± 5.2 kg/m² in the LMM group and 28.1 ± 4.7 kg/m² in the normal group (p < 0.001). In multivariate analyses, predictors of LMM were: falls (OR = 1.14, p = 0.016), TSH levels (OR = 1.08, p = 0.018, per 1 μUI/L-increase), serum creatinine levels (OR = 11.11, p < 0.001, per 1 mg/dL-decrease), and visceral adipose tissue (VAT) mass (OR = 1.17, p < 0.001, per 100 g increase).

CONCLUSIONS

Falls, high TSH, low creatinine, and high VAT were risk factors for LMM in older women. More attention should be paid to these factors, since they are potentially reversible with adequate intervention.

Trunk Skeletal Muscle Mass and Phase Angle Measured by Bioelectrical Impedance Analysis are Associated with the Chance of Femoral Neck Fracture in Very Elderly People

Background

The study aimed to investigate the potential association of trunk skeletal muscle mass (tSM) and phase angle measured by bioelectrical impedance analysis (BIA) with the chance of femoral neck fractures in very elderly people.

Patients and Methods

This case-control study enrolled 78 femoral neck fracture patients aged over 75 years (29 males) and 1:2 matched healthy controls. All participants were subjected to BIA examination by specialists. tSM, the corrected values by height squared of tSM (tSMI) and phase angle were compared between fracture patients and controls. Multivariate logistic regression was performed to explore the strength of association of femoral neck fracture with tSM, tSMI, and phase angle.

Results

tSM (kg) of fracture patients was significantly lower than those of controls in all participants (women: 13.49±0.42 vs 15.44±0.39, p<0.05; men: 15.30±0.71 vs 17.54±0.78, p<0.05). In the sarcopenic subgroup, fracture patients also got a lower tSM than controls (women: 12.58±0.21 vs 13.62±0.16, p<0.05; men:14.41±0.29 vs 16.07±0.21, p<0.05). The comparison of tSMI between the two groups was similar to that of tSM. Phase angle (°) at 50 kHz in fracture patients was significantly lower than that of controls in women and men (women: 3.70±0.32 vs 4.61±0.21, p<0.05; men: 3.50±0.20 vs 3.84±0.22, p<0.05). Multivariate logistic regression analysis demonstrated higher fracture chance with significantly associated decreased tSM [women: OR (95% CI): 0.78(0.67–0.91); men: 0.74(0.64–0.86)] and tSMI [women: OR (95% CI): 0.72(0.61–0.85); men: 0.69 (0.59–0.81)]. In addition, per 1° increase of phase angle in the trunk could decrease the fracture risk by 14% for women [OR (95% CI): 0.86 0.79–0.94)] and 29% for men [OR (95% CI): 0.71 (0.64–0.79)].

Conclusion

This study indicates a decrease in tSM, tSMI, and phase angle measured by BIA is significantly related to the increased chance of femoral neck fracture in people aged over 75 years. Strengthening the mass and strength of trunk skeletal muscles may help reduce the risk of femoral neck fracture in elderly patients.

Prevalence of muscle dysfunction concomitant with osteoporosis in a home-dwelling Danish population aged 65-93 years - The Copenhagen Sarcopenia Study

INTRODUCTION

As life expectancy increases, a growing percentage of older individuals with age-related diseases such as osteoporosis and sarcopenia are expected. Patients with both conditions, i.e. patient with osteosarcopenia, are suggested to have a higher risk of fall and fracture compared to individuals with either condition.

AIM

To investigate the potential relationship between low bone mineral density (BMD) and muscle dysfunction in a Danish cohort of older home-dwelling individuals. Furthermore, to examine the prevalence of osteosarcopenia and alterations in prevalence depending on cut-off values chosen.

METHOD

Measures of BMD, relative appendicular lean mass and hand grip strength were assessed in 529 individuals aged 65+ from the population-based cross-sectional Copenhagen Sarcopenia Study (CSS). Osteoporosis was diagnosed according to the World Health Organization guidelines. Sarcopenia was diagnosed in accordance with the guidelines from the European Working Group on Sarcopenia in Older People (EWGSOP2) with application of cut-off values from the EWGSOP2 paper compared to cut-off values derived from a local cohort (CSS).

RESULTS

19.2% had osteoporosis (66 women and 35 men), whereas 2.7% (6 women and 8 men) and 4.2% (7 women and 15 men) had sarcopenia with application of EWGSOP2 and CSS cut-off values, respectively. Using the EWGSOP2 cut-off values, 1.5% (4 women and 4 men) were diagnosed with osteosarcopenia compared to 1.4% (4 women and 3 men) using CSS cut-off values. In the osteoporosis sub-population, 8% (EWGSOP2) and 7% (CSS) had sarcopenia and within the sarcopenia sub-population, 61.5% (EWGSOP2) and 33.3% (CSS) had osteoporosis. At all sites, BMD was lower among individuals with sarcopenia and sarcopenia increased the risk of osteoporosis (odds ratios: EWGSOP2: 7.3 (p < 0.001) and CSS: 2.2 (ns)).

CONCLUSION

Osteosarcopenia was present in 1.5% of a group of healthy home-dwelling older individuals. Notably, individuals with sarcopenia had lower BMD and a higher risk of osteoporosis, whereas the opposite (prevalence of sarcopenia in individuals with osteoporosis) was not as frequent. Our data indicate that screening for sarcopenia and osteoporosis should be performed simultaneously in older individuals at high risk of falls and fractures. However, further studies with outcome-related results are needed to identify optimal measures of osteosarcopenia and cut-off values for sarcopenia.

Influence of sarcopenia on bone health parameters in a group of eumenorrheic obese premenopausal women

INTRODUCTION

The aim of this study was to compare bone mineral density (BMD) and geometric indices of hip bone strength in a group of obese sarcopenic premenopausal women (n = 27) and a group of obese premenopausal women with normal appendicular lean mass (ALM)/body mass index ratio (BMI) (n = 26).

MATERIALS AND METHODS

The ALM/BMI criterion of The Foundation for the National Institute of Health was used; women with an ALM/BMI ratio < 0.512 m² were considered obese sarcopenic. Body composition and bone variables were measured by DXA. DXA measurements were completed for the whole body (WB), lumbar spine (L1-L4), total hip (TH) and femoral neck (FN). Hip geometry parameters including cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), section modulus (Z), strength index (SI) and buckling ratio (BR) were derived by DXA.

RESULTS

Age, weight and BMI were not significantly different between the two groups. Height, lean mass, skeletal muscle mass index, ALM and the ratio ALM/BMI were significantly higher in obese women with normal ALM/BMI ratio compared to obese sarcopenic women. Fat mass percentage was significantly higher in obese sarcopenic women compared to obese women with normal ALM/BMI ratio. WB BMC, TH BMD, FN BMD, CSA, CSMI and Z were significantly higher in obese women with normal ALM/BMI ratio compared to obese sarcopenic women. In the whole population (n = 53), ALM and the ratio ALM/BMI were positively correlated to WB BMC, CSA, CSMI and Z.

CONCLUSION

The present study suggests that sarcopenia negatively influences bone mineral density and hip geometry parameters before menopause in eumenorrheic obese women.

Extracellular vesicles secreted from mouse muscle cells suppress osteoclast formation: Roles of mitochondrial energy metabolism

Recent reports have described the interactions of muscle and bone. Various muscle-derived humoral factors, known as myokines, affect bone. Although extracellular vesicles (EVs) play a vital role in physiological and pathophysiological processes by transferring their contents to distant tissues during bone metabolism, the roles of EVs in the muscle-bone interactions remain unknown. In the present study, we investigated the effects of EVs secreted from mouse muscle C2C12 cells on mouse bone cells and mitochondrial biogenesis. EVs secreted from C2C12 cells (Myo-EVs) were isolated from the conditioned medium of C2C12 cells by ultracentrifugation. Myo-EVs suppressed osteoclast formation as well as the expression of tartrate-resistant acid phosphatase, cathepsin K, nuclear factor of activated T-cells cytoplasmic 1 and dendritic cell-specific transmembrane protein induced by receptor activator of nuclear factor κB ligand (RANKL) in mouse bone marrow cells and preosteoclastic Raw264.7 cells. Moreover, Myo-EVs suppressed oxygen consumption and mRNA expression of the mitochondrial biogenesis markers enhanced by RANKL in these cells. However, Myo-EVs did not affect the phenotypes or mitochondrial biogenesis of mouse primary osteoblasts. In conclusion, the present study showed for the first time that Myo-EVs suppress osteoclast formation and mitochondrial energy metabolism in mouse bone marrow and Raw264.7 cells. EVs secreted from skeletal muscles might be a crucial mediator of muscle-bone interactions.

Osteoporosis-related Vertebral Fragility Fractures: A Review and Analysis of the American Orthopaedic Association's Own the Bone Database

STUDY DESIGN

Retrospective cohort study of the Own the Bone database which is a fracture liaison service designed to improve recognition and treatment of osteoporosis.

OBJECTIVE

To use the Own the Bone (OTB) database to 1) examine the specific demographics of patients presenting with a low-energy clinical vertebral fracture (VFX) and 2) compare demographic and fracture-specific risk factors between patients with clinical VFX versus patients with nonvertebral low-energy fracture (NVFX).

SUMMARY OF BACKGROUND DATA

Large database studies have described risk factors for developing VFX. It is well described that a history of previous VFX portends an increased risk of future VFX. Few studies have reported cohorts from a fracture liaison service such as the OTB initiative.

METHODS

35,039 unique cases of fragility fracture occurred between 2009 and 2016 and were included in analysis. VFX accounted for 3395 (9.9%) of the presenting fractures at OTB enrollment. The demographics, lifestyle factors, medication use, and fracture-specific data for patients in the OTB registry with vertebral fractures were summarized and then statistically compared to those with nonvertebral fragility fractures.

RESULTS

The majority of VFX patients were Caucasian, postmenopausal women (74.4%). There was an increased likelihood of presenting with a vertebral fracture in patients who sustained a previous VFX after the age of 50, while patients who sustained a prior nonvertebral fracture (NVFX) were more likely to present with a subsequent NVFX. After controlling for patients with a history of fracture after the age of 50, VFX patients (vs. NVFX) were more likely to be age 70-79, class 1 obesity, with a history of taking anti-osteoporotic prescription medications.

CONCLUSIONS

Multiple factors were associated with a significantly increased risk of VFX compared with NVFX. Understanding the risk factors unique to fragility VFX is a critical component for targeting "at-risk" patients and preventing future osteoporosis-related fractures and their consequences.

LEVEL OF EVIDENCE

4.

Corticospinal Control of Human Locomotion as a New Determinant of Age-Related Sarcopenia: An Exploratory Study

Sarcopenia is a muscle disease listed within the ICD-10 classification. Several operational definitions have been created for sarcopenia screening; however, an international consensus is lacking. The Centers for Disease Control and Prevention have recently recognized that sarcopenia detection requires improved diagnosis and screening measures. Mounting evidence hints towards changes in the corticospinal communication system where corticomuscular coherence (CMC) reflects an effective mechanism of corticospinal interaction. CMC can be assessed during locomotion by means of simultaneously measuring Electroencephalography (EEG) and Electromyography (EMG). The aim of this study was to perform sarcopenia screening in community-dwelling older adults and explore the possibility of using CMC assessed during gait to discriminate between sarcopenic and non-sarcopenic older adults. Receiver Operating Characteristic (ROC) curves showed high sensitivity, precision and accuracy of CMC assessed from EEG Cz sensor and EMG sensors located over Musculus Vastus Medialis [Cz-VM; AUC (95.0%CI): 0.98 (0.92-1.04), sensitivity: 1.00, 1-specificity: 0.89, p < 0.001] and with Musculus Biceps Femoris [Cz-BF; AUC (95.0%CI): 0.86 (0.68-1.03), sensitivity: 1.00, 1-specificity: 0.70, p < 0.001]. These muscles showed significant differences with large magnitude of effect between sarcopenic and non-sarcopenic older adults [Hedge's g (95.0%CI): 2.2 (1.3-3.1), p = 0.005 and Hedge's g (95.0%CI): 1.5 (0.7-2.2), p = 0.010; respectively]. The novelty of this exploratory investigation is the hint toward a novel possible determinant of age-related sarcopenia, derived from corticospinal control of locomotion and shown by the observed large differences in CMC when sarcopenic and non-sarcopenic older adults are compared. This, in turn, might represent in future a potential treatment target to counteract sarcopenia as well as a parameter to monitor the progression of the disease and/or the potential recovery following other treatment interventions.

Does Combined Osteopenia/Osteoporosis and Sarcopenia Confer Greater Risk of Falls and Fracture Than Either Condition Alone in Older Men? The Concord Health and Ageing in Men Project

BACKGROUND

It is unclear whether older men with osteopenia/osteoporosis and sarcopenia (so-called osteosarcopenia) are at greater risk of falls and fractures than those with either condition alone.

METHODS

One thousand five hundred seventy-five community-dwelling men aged ≥70 years had appendicular lean mass, total hip and lumbar spine bone mineral density determined by dual-energy x-ray absorptiometry, and completed hand grip strength and gait speed tests. Osteopenia/osteoporosis was defined as a T-score at any site ≤-1.0 SD. Sarcopenia was defined using the European Working Group on Sarcopenia algorithm. Participants were contacted every 4 months for 6 ± 2 years to ascertain incident fractures (confirmed by radiographic reports) and for 2 years for incident falls.

RESULTS

Prevalence of osteosarcopenia was 8%, while 34% of participants had osteopenia/osteoporosis alone and 7% had sarcopenia alone. Men with osteosarcopenia had significantly increased fall (incidence rate ratio: 1.41; 95% confidence interval [CI]: 1.02 to 1.95) and fracture risk (hazard ratio: 1.87; 95% CI: 1.07 to 3.26) compared with men with neither osteopenia/osteoporosis nor sarcopenia. There was no statistical interaction between osteopenia/osteoporosis and sarcopenia, and falls and fracture risk were not different for osteosarcopenia compared with either condition alone (all p > .05).

CONCLUSIONS

Community-dwelling older men with combined osteopenia/osteoporosis and sarcopenia do not have increased falls and fracture risk compared with those with either condition. Further research is required to clarify whether the term "osteosarcopenia" has any meaning above and beyond either term alone and therefore potential clinical utility for falls and fracture prediction.

Sarcopenia, osteoporosis and the burden of prevalent vertebral fractures: a cross-sectional study of 350 women with hip fracture

BACKGROUND

The concurrent presence of sarcopenia and osteoporosis may enhance fracture risk.

AIM

The aim of this study was to evaluate the association between sarcopenia, osteoporosis, or the concurrent presence of both the conditions (osteosarcopenia) and the burden (number and severity) of vertebral fractures in women with hip fracture.

DESIGN

Cross-sectional study.

SETTING

Division of Physical and Rehabilitation Medicine.

POPULATION

We studied 350 women with subacute hip fracture.

METHODS

Lateral radiographs of the spine were taken 18.2±4.5 days after fracture occurrence and the Spine Deformity Index (SDI) was calculated. Body composition was assessed by dual-energy X-ray absorptiometry. Low muscle mass was identified with appendicular lean mass <15.02 kg and low bone mineral density with a femoral T-Score <-2.5.

RESULTS

The presence of sarcopenia (P=0.033) and osteoporosis (P=0.032) was associated with the SDI scores independently of each other and independently of age, percentage of body fat and hip-fracture type. The 350 women were categorized into 3 groups according to the absence of both osteoporosis and sarcopenia (N.=25), presence of either osteoporosis or sarcopenia (N.=95) or presence of osteosarcopenia (N.=230). We found a significant difference in SDI scores across the 3 groups: χ2 (2, N.=350) = 15.29; P<0.001. The categorization of the 350 women into the 3 groups was associated with the SDI scores (P=0.001) independently of age, percentage of body fat and hip-fracture type.

CONCLUSIONS

Both osteoporosis and sarcopenia were independently associated with the burden of prevalent vertebral fractures in women with hip fracture. The concurrent presence of sarcopenia and osteoporosis was associated with a higher SDI Score than the presence of only one of the 2 conditions.

CLINICAL REHABILITATION IMPACT

Subjects with both low bone mass and low muscle mass should be considered at particularly high risk for vertebral fractures. Interventions targeting both the components of the muscle-bone unit, including exercise, nutrition, and possibly new medications, should be investigated to optimize fracture prevention.

Association of sarcopenic obesity with the risk of all-cause mortality among adults over a broad range of different settings: a updated meta-analysis

Background

Previous cohort studies investigating the association between sarcopenic obesity (SO) and all-cause mortality among adult people have been inconsistent. We performed a meta-analysis to determine if SO is a predictor of all-cause mortality.

Methods

Prospective cohort studies that evaluated the association between SO and mortality in older people were identified via a systematic search of three electronic databases (PubMed, EMBASE, and the Cochrane Library). A random-effects model was applied to combine the results. We considered the methods recommeded by consensuses (dual X-ray absorptiometry,bio-impedancemetry, anthropometric measures or CT scan) to assess sarcopenic obesity.

Results

Of the 603 studies identified through the systematic review, 23 (Participants: 50866) were included in the meta-analysis. The mean age ranged from 50 to 82.5 years.SO was significantly associated with a higher risk of all-cause mortality among adult people (pooled HR = 1.21, 95% confidence interval [95% CI] = 1.10–1.32, p < 0.001, I² = 64.3%). Furthermore, the subgroup analysis of participants showed that SO was associated with all-cause mortality (pooled HR = 1.14, 95% CI: 1.06–1.23) among community-dwelling adult people; similarly, this association was found in hospitalized patients (pooled HR = 1.65, 95% CI: 1.17–2.33). Moreover, the subgroup analysis demonstrated that SO was associated with all-cause mortality when using skeletal muscle mass (SMM) criteria, muscle strength criteria, and skeletal muscle index (SMI) criteria (HR = 1.12, 95% CI: 1.01–1.23; HR = 1.18, 95% CI: 1.05–1.33; and HR = 1.53, 95% CI: 1.13–2.07, respectively). In addition, we analyzed SO on the basis of obesity definition and demonstrated that participants with a SO diagnosis based on waist circumference (WC) (HR = 1.24, 95% CI: 1.09–1.40), body mass index (BMI) (HR = 1.29, 95% CI: 1.04–1.59), or visceral fat area (HR = 2.54, 95% CI: 1.83–3.53) have a significantly increase mortality risk compared with those without SO.

Conclusion

Based on our update of existing scientific researches, SO is a significant predictor of all-cause mortality among older people, particularly hospitalized patients. Therefore, it is important to diagnose SO and to treat the condition to reduce mortality rates among older people.

Electronic supplementary material

The online version of this article (10.1186/s12877-019-1195-y) contains supplementary material, which is available to authorized users.

Sarcopenia and its association with falls and fractures in older adults: A systematic review and meta-analysis

Sarcopenia is a potentially modifiable risk factor for falls and fractures in older adults, but the strength of the association between sarcopenia, falls, and fractures is unclear. This study aims to systematically assess the literature and perform a meta-analysis of the association between sarcopenia with falls and fractures among older adults. A literature search was performed using MEDLINE, EMBASE, Cochrane, and CINAHL from inception to May 2018. Inclusion criteria were the following: published in English, mean/median age ≥ 65 years, sarcopenia diagnosis (based on definitions used by the original studies' authors), falls and/or fractures outcomes, and any study population. Pooled analyses were conducted of the associations of sarcopenia with falls and fractures, expressed in odds ratios (OR) and 95% confidence intervals (CIs). Subgroup analyses were performed by study design, population, sex, sarcopenia definition, continent, and study quality. Heterogeneity was assessed using the I² statistics. The search identified 2771 studies. Thirty-six studies (52 838 individuals, 48.8% females, and mean age of the study populations ranging from 65.0 to 86.7 years) were included in the systematic review. Four studies reported on both falls and fractures. Ten out of 22 studies reported a significantly higher risk of falls in sarcopenic compared with non-sarcopenic individuals; 11 out of 19 studies showed a significant positive association with fractures. Thirty-three studies (45 926 individuals) were included in the meta-analysis. Sarcopenic individuals had a significant higher risk of falls (cross-sectional studies: OR 1.60; 95% CI 1.37-1.86, P < 0.001, I²  = 34%; prospective studies: OR 1.89; 95% CI 1.33-2.68, P < 0.001, I²  = 37%) and fractures (cross-sectional studies: OR 1.84; 95% CI 1.30-2.62, P = 0.001, I²  = 91%; prospective studies: OR 1.71; 95% CI 1.44-2.03, P = 0.011, I²  = 0%) compared with non-sarcopenic individuals. This was independent of study design, population, sex, sarcopenia definition, continent, and study quality. The positive association between sarcopenia with falls and fractures in older adults strengthens the need to invest in sarcopenia prevention and interventions to evaluate its effect on falls and fractures.

RANKL inhibition improves muscle strength and insulin sensitivity and restores bone mass

Receptor activator of Nfkb ligand (RANKL) activates, while osteoprotegerin (OPG) inhibits, osteoclastogenesis. In turn a neutralizing Ab against RANKL, denosumab improves bone strength in osteoporosis. OPG also improves muscle strength in mouse models of Duchenne's muscular dystrophy (mdx) and denervation-induce atrophy, but its role and mechanisms of action on muscle weakness in other conditions remains to be investigated. We investigated the effects of RANKL inhibitors on muscle in osteoporotic women and mice that either overexpress RANKL (HuRANKL-Tg+), or lack Pparb and concomitantly develop sarcopenia (Pparb-/-). In women, denosumab over 3 years improved appendicular lean mass and handgrip strength compared to no treatment, whereas bisphosphonate did not. HuRANKL-Tg+ mice displayed lower limb force and maximal speed, while their leg muscle mass was diminished, with a lower number of type I and II fibers. Both OPG and denosumab increased limb force proportionally to the increase in muscle mass. They markedly improved muscle insulin sensitivity and glucose uptake, and decrease anti-myogenic and inflammatory gene expression in muscle, such as myostatin and protein tyrosine phosphatase receptor-γ. Similarly, in Pparb-/-, OPG increased muscle volume and force, while also normalizing their insulin signaling and higher expression of inflammatory genes in skeletal muscle. In conclusions, RANKL deteriorates, while its inhibitor improves, muscle strength and insulin sensitivity in osteoporotic mice and humans. Hence denosumab could represent a novel therapeutic approach for sarcopenia.

The fracture predictive ability of a musculoskeletal composite score in old men - data from the MrOs Sweden study

Background

Detection of high-risk individuals for fractures are needed. This study assessed whether level of physical activity (PA) and a musculoskeletal composite score could be used as fracture predictive tools, and if the score could predict fractures better than areal bone mineral density (aBMD).

Methods

MrOs Sweden is a prospective population-based observational study that at baseline included 3014 men aged 69–81 years. We assessed femoral neck bone mineral content (BMC), bone area, aBMD and total body lean mass by dual energy X-ray absorptiometry, calcaneal speed of sound by quantitative ultrasound and hand grip strength by a handheld dynamometer. PA was assessed by the Physical Activity Scale for the Elderly (PASE) questionnaire. We followed the participants until the date of first fracture, death or relocation (median 9.6 years). A musculoskeletal composite score was calculated as mean Z-score of the five measured traits. A Cox proportional hazards model was used to analyze the association between the musculoskeletal traits, the composite score and incident fractures (yes/no) during the follow-up period. Data are presented as hazard ratios (HR) with 95% confidence intervals (95% CI) for fracture for a + 1 standard deviation (SD) change (+ 1 Z-score) in the various musculoskeletal traits as well as the composite score. We used a linear regression model to estimate the association between level of PA, measured as PASE-score and the different musculoskeletal traits as well as the composite score.

Results

A + 1 SD higher composite score was associated with an incident fracture HR of 0.61 (0.54, 0.69), however not being superior to aBMD in fracture prediction. A + 1 SD higher PASE-score was associated with both a higher composite score and lower fracture incidence (HR 0.83 (0.76, 0.90)).

Conclusions

The composite score was similar to femoral neck aBMD in predicting fractures, and also low PA predicted fractures. This highlights the need of randomized controlled trials to evaluate if PA could be used as a fracture preventive strategy.

Appendicular lean mass and fracture risk assessment: implications for FRAX® and sarcopenia

The vast majority of current sarcopenia definitions use DXA-derived appendicular lean mass (DXA ALM) as an approximation of muscle mass. However, there is increasing evidence that ALM is poorly predictive of incident fractures. In this editorial, we describe findings from several cohorts suggesting that DXA ALM gives only limited information on the risk of incident fracture, and that in the US MrOS, WHI and Health ABC cohorts, accounting for femoral neck bone mineral density may entirely remove ALM-fracture associations. These observations raise important questions about the role of DXA ALM both in sarcopenia definitions and as a potential input variable for FRAX. We conclude that DXA ALM is unlikely to be a useful addition to the FRAX tool, but that other means of estimating muscle mass, such as those derived from creatine dilution or peripheral quantitative CT, might offer more value for fracture risk assessment.

The relationship between sarcopenia and fragility fracture-a systematic review

Sarcopenia is a common geriatric syndrome characterized by progressive decrease of muscle mass and function leading to an increased risk of physical disability, poor quality of life, and mortality. Increasing evidence shows that sarcopenia is related with fragility fractures. This systematic review aimed to summarize the following: (1) the prevalence of sarcopenia in patients with fragility fracture and (2) the associated risk factors for fragility fracture in patients with sarcopenia. Literature search was conducted in PubMed and Cochrane databases. Studies with the prevalence of sarcopenia in elderly patients with fragility fracture and associated risk factors in patients with sarcopenia were included. A total of 15 papers were included, with 10 reporting sarcopenia prevalence, and 5 on fracture risk in patients with sarcopenia. The prevalence of sarcopenia after fracture ranged from 12.4 to 95% in males and 18.3 to 64% in females. The prevalence of sarcopenia in elderly patients with fragility fracture was high, especially in men. Two studies showed that sarcopenia was a risk factor for fragility fracture when associated with low bone mineral density (BMD) but only in men. Caution should be taken for male patients with sarcopenia and low BMD, which is related to significantly increased risk of fractures. There is a pressing need for further research on sarcopenia and its risk on fragility fracture to better understand the relationship, pathophysiology, and mechanisms, which may shed light on potential interventions to improve clinical outcomes.

Predictive value of percentage body fat in aging people with low muscle mass: A 2.2-year longitudinal study

BACKGROUND

The aim of this study was to evaluate the usefulness of percentage body fat (PBF) in screening for the risk of low muscle mass (LMM) in elderly people.

METHODS

A prospective study was carried out in Chinese PLA General Hospital with 413 participants who underwent baseline and an average 2.2-year follow-up health check-up examinations.

RESULTS

The average age of the participants at baseline was 63.6 years. The incidence of newly developed LMM was 10.3% in men and 18.2% in women during follow-up. Linear regression demonstrated that baseline PBF were negatively correlated with follow-up total muscle mass index (TMMI) in both men and women (β=-0.124 for men and -0.233 for women, all P < 0.001). The cut-off points of baseline PBF in elderly people for future LMM were 25.45% in men and 30.95% in women and were identified by Receiver Operator Curves (ROC).

CONCLUSIONS

Elderly people with a high PBF had a higher risk of new LMM, which suggested that baseline PBF had a close relationship with future LMM and the screening of high PBF should be paid enough attention in health care management in the senior people.

Mediterranean diet is associated with bone mineral density and muscle mass in postmenopausal women

PURPOSE

This study aimed to investigate the association between the Mediterranean diet (MD), body composition, and bone mineral density (BMD) in postmenopausal women.

METHODS

In this cross-sectional study, 105 apparently healthy postmenopausal women aged between 45 and 65 years were included. BMD, percentage body fat, and appendicular lean mass index (ALMI, appendicular lean mass/height squared) were assessed by dual-energy X-ray absorptiometry. Dietary intake was assessed by a validated food frequency questionnaire. Assessment of MD adherence was based on intake of cereals, vegetables, fruits, meats, dairy products, fish, red wine, and olive oil, and expressed as the Mediterranean diet score (MDS).

RESULTS

Women with higher adherence to the MD had higher ALMI (6.6 ± 0.8 kg/m² vs. 6.3 ± 0.7 kg/m²; p = 0.039) and lumbar spine BMD (1.076 ± 0.149 vs. 0.997 ± 0.143 g/cm²; p = 0.007) compared to those with lower MDS. Linear regression analysis adjusted for previous hormone therapy, previous smoking behavior, and habitual physical activity showed an independent positive contribution of MDS to lumbar spine BMD (mean difference 0.088 g/cm², 95% confidence interval 0.028-0.147; p = 0.004) and ALMI (mean difference 0.296 kg/m², 95% confidence interval 0.020-0.591; p = 0.049).

CONCLUSION

Bone mineral density at the lumbar spine and ALMI were positively associated with the MDS in a sample of postmenopausal women from a non-Mediterranean region.

The serum creatinine to cystatin C ratio predicts bone fracture in patients with type 2 diabetes: The Fukuoka Diabetes Registry

AIMS

Sarcopenia is involved in the pathogenesis of increased fracture risk associated with diabetes. The serum creatinine to cystatin C (Cr/CysC) ratio has been reported as a surrogate marker for muscle mass. We aimed to prospectively investigate the relationship between the Cr/CysC ratio and fracture risk.

METHODS

We followed 1911 postmenopausal women and 2689 men with type 2 diabetes (mean age, 66 years) for a median of 5.3 years, and divided into Cr/CysC ratio quartiles by sex. The primary outcome was fragility fractures and the secondary outcome was any fracture.

RESULTS

Fragility fractures occurred in 192 participants, and any fracture occurred in 645 participants. Multivariate-adjusted hazard ratios (95% CI) for fragility fractures were 2.15 (1.19-3.88) (Q1), 1.63 (0.89-2.98) (Q2), 1.34 (0.72-2.51) (Q3) and 1.0 (ref.) (Q4) in postmenopausal women, and 1.75 (0.64-4.50) (Q1), 2.09 (0.83-5.26) (Q2), 1.56 (0.58-4.18) (Q3) and 1.0 (ref.) (Q4) in men. Those for any fracture were 1.46 (1.07-1.98) (Q1), 1.33 (0.98-1.81) (Q2), 1.40 (1.03-1.88) (Q3) and 1.0 (ref.) (Q4) in postmenopausal women, and 2.33 (1.54-3.54) (Q1), 2.02 (1.54-3.04) (Q2), 1.13 (0.71-1.78) (Q3) and 1.0 (ref.) (Q4) in men.

CONCLUSIONS

A lower Cr/CysC ratio is a significant risk factor for fractures in patients with type 2 diabetes.

Implications of low muscle mass across the continuum of care: a narrative review

Abnormalities in body composition can occur at any body weight. Low muscle mass is a predictor of poor morbidity and mortality and occurs in several populations. This narrative review provides an overview of the importance of low muscle mass on health outcomes for patients in inpatient, outpatient and long-term care clinical settings. A one-year glimpse at publications that showcases the rapidly growing research of body composition in clinical settings is included. Low muscle mass is associated with outcomes such as higher surgical and post-operative complications, longer length of hospital stay, lower physical function, poorer quality of life and shorter survival. As such, the potential clinical benefits of preventing and reversing this condition are likely to impact patient outcomes and resource utilization/health care costs. Clinically viable tools to measure body composition are needed for routine screening and intervention. Future research studies should elucidate the effectiveness of multimodal interventions to counteract low muscle mass for optimal patient outcomes across the healthcare continuum. Key messages Low muscle mass is associated with several negative outcomes across the healthcare continuum. Techniques to identify and counteract low muscle mass in clinical settings are needed.

Measures of Physical Performance and Muscle Strength as Predictors of Fracture Risk Independent of FRAX, Falls, and aBMD: A Meta-Analysis of the Osteoporotic Fractures in Men (MrOS) Study

Measures of muscle mass, strength, and function predict risk of incident fractures, but it is not known whether this risk information is additive to that from FRAX (fracture risk assessment tool) probability. In the Osteoporotic Fractures in Men (MrOS) Study cohorts (Sweden, Hong Kong, United States), we investigated whether measures of physical performance/appendicular lean mass (ALM) by DXA predicted incident fractures in older men, independently of FRAX probability. Baseline information included falls history, clinical risk factors for falls and fractures, femoral neck aBMD, and calculated FRAX probabilities. An extension of Poisson regression was used to investigate the relationship between time for five chair stands, walking speed over a 6 m distance, grip strength, ALM adjusted for body size (ALM/height2 ), FRAX probability (major osteoporotic fracture [MOF]) with or without femoral neck aBMD, available in a subset of n = 7531), and incident MOF (hip, clinical vertebral, wrist, or proximal humerus). Associations were adjusted for age and time since baseline, and are reported as hazard ratios (HRs) for first incident fracture per SD increment in predictor using meta-analysis. 5660 men in the United States (mean age 73.5 years), 2764 men in Sweden (75.4 years), and 1987 men in Hong Kong (72.4 years) were studied. Mean follow-up time was 8.7 to 10.9 years. Greater time for five chair stands was associated with greater risk of MOF (HR 1.26; 95% CI, 1.19 to 1.34), whereas greater walking speed (HR 0.85; 95% CI, 0.79 to 0.90), grip strength (HR 0.77; 95% CI, 0.72 to 0.82), and ALM/height2 (HR 0.85; 95% CI, 0.80 to 0.90) were associated with lower risk of incident MOF. Associations remained largely similar after adjustment for FRAX, but associations between ALM/height2 and MOF were weakened (HR 0.92; 95% CI, 0.85 to 0.99). Inclusion of femoral neck aBMD markedly attenuated the association between ALM/height2 and MOF (HR 1.02; 95% CI, 0.96 to 1.10). Measures of physical performance predicted incident fractures independently of FRAX probability. Whilst the predictive value of ALM/height2 was substantially reduced by inclusion of aBMD requires further study, these findings support the consideration of physical performance in fracture risk assessment. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

Effects of activated vitamin D, alfacalcidol, and low-intensity aerobic exercise on osteopenia and muscle atrophy in type 2 diabetes mellitus model rats

Diabetes mellitus causes secondary osteoporosis and muscle atrophy. The ability of alfacalcidol (ALF) and exercise (Exe) to inhibit osteoporosis and muscle atrophy in type 2 diabetes mellitus (T2DM) model rats was examined. Twenty-week-old Otsuka Long-Evans Tokushima Fatty rats were randomized to ALF (orally 0.1 μg/kg/day), Exe (treadmill exercise at 10 m/min, 60 min/day, 5 days/week), Comb (ALF and Exe), and Cont (T2DM control treated with vehicle and no exercise) groups (n = 8–10 per group). Sedentary Long-Evans Tokushima Otsuka rats were used as a non-hyperphagic control. After treatment for 2 or 6 weeks, blood glucose (BG) levels, cross-sectional area (CSA) of tibialis anterior muscle fibers, femoral bone mineral density (BMD), and relative quantities of muscle anabolic markers (Pax7, MyoD, and myogenin) and catabolic markers (Atrogin-1, MuRF1, and REDD1) of the soleus muscle assessed by real-time polymerase chain reaction assays were measured. Exe and Comb treatments for 6 weeks decreased BG levels compared with those of the Cont group. ALF, Exe, and Comb treatments for 2 and 6 weeks recovered the CSA compared with that of the Cont group. ALF and Comb treatments for 6 weeks increased femoral BMDs compared with those of the Cont group. After 2 weeks of treatment, Comb treatment increased MyoD expression and decreased MuRF1 expression. ALF or Exe monotherapy significantly decreased Atrogin-1 or MuRF1 expression after 2 weeks of treatment, respectively. After 6 weeks of treatment, ALF and Comb treatments decreased Atrogin-1 and REDD1. These results demonstrate that a combination of ALF and Exe improved CSA from the early phase of treatment by stimulating skeletal muscle differentiation and suppressing muscle catabolic genes. Improvements in BG, BMD, and CSA were observed as long-term effects of the combination therapy. Continued suppression of muscle catabolic genes was observed as a background to these effects.