Incremental Predictive Value of Sarcopenia for Incident Fracture in an Elderly Chinese Cohort: Results From the Osteoporotic Fractures in Men (MrOs) Study

Sarcopenia Prevalence and Risk Factors Among Older Adults in Bangkok, Thailand: A Cross-Sectional Study

OBJECTIVES

This study aimed to investigate the prevalence of sarcopenia among older Thai adults residing in Bangkok and identify associated risk factors.

METHODS

This cross-sectional study included Thai adults aged ≥60 years. All participants underwent assessments using the Yubi-wakka test, anthropometric measurements, bioelectrical impedance analysis, handgrip strength tests, and physical performance evaluations. Information on demographic characteristics, chronic health conditions, nutritional status, and medication use was also collected. Sarcopenia was diagnosed according to the 2019 Asian Working Group for Sarcopenia criteria. Statistical analyses were performed using the independent t-test, Chi-square test, and logistic regression to identify risk factors.

RESULTS

Among the 600 participants, the overall prevalence of sarcopenia was 19%. The multivariate analysis identified 13 significant risk factors associated with sarcopenia, including age ≥75 years (odds ratio [OR]=10.6, 95% confidence interval [CI]=3.7-30.2), higher education level (year) (OR=0.85, 95% CI=0.74-0.98), lower income level (OR=5.4, 95% CI=1.4-21.4), Barthel index <90 (OR=11.0, 95% CI=3.5-34.5), lower body mass index (OR=0.7, 95% CI=0.6-0.8), low calf circumference (OR=7.6, 95% CI=2.5-23.3), fall in the past year (OR, 3.1; 95% CI, 1.4-6.6), frailty (OR, 2.3; 95% CI, 1.1-4.5), malnutrition (OR=3.5, 95% CI=1.3-9.3), history of stroke (OR=7.5, 95% CI=1.3-41.4), vitamin D deficiency (OR=9.4, 95% CI=1.1-82.5), knee osteoarthritis (OR=6.3, 95% CI=1.57-25.31), and malignancy (OR=4.8, 95% CI=1.01-22.70).

CONCLUSION

This study evaluated the sarcopenia status across a diverse demographic of older Thai adults using comprehensive assessments, and examined the impact of socioeconomic factors and various chronic conditions on the occurrence of sarcopenia.

Blood Profiles of Community-Dwelling People with Sarcopenia: Analysis Based on the China Health and Retirement Longitudinal Study

INTRODUCTION

Routine blood factors can be economical and easily accessible candidates for sarcopenia screening and monitoring. The associations between sarcopenia and routine blood factors remain unclear. This study aimed to examine sarcopenia and blood factor associations based on a nation-wide cohort in China.

METHODS

A total of 1,307 participants and 17 routine blood indices were selected from two waves (year 2011 and year 2015) of the China Health and Retirement Longitudinal Study (CHARLS). The diagnosis of sarcopenia was based on the criteria proposed by the Asian Working Group for Sarcopenia (AWGS 2019). Generalized mixed-effects models were performed for association analyses. A logistic regression (LR) model was conducted to examine the predictive power of identifying significant blood factors for sarcopenia.

RESULTS

A higher sarcopenia risk was cross-sectionally associated with elevated blood concentrations of high-sensitivity C-reactive protein (hsCRP) (OR = 1.030, 95% CI [1.007, 1.053]), glycated hemoglobin (HbA1c) (OR = 1.407, 95% CI [1.126, 1.758]) and blood urea nitrogen (BUN) (OR = 1.044, 95% CI [1.002, 1.089]), and a decreased level of glucose (OR = 0.988, 95% CI [0.979, 0.997]). A higher baseline hsCRP value (OR = 1.034, 95% CI [1.029, 1.039]) and a greater over time change in hsCRP within 4 years (OR = 1.034, 95% CI [1.029, 1.039]) were associated with a higher sarcopenia risk. A higher BUN baseline value was related to a decreased sarcopenia risk over time (OR = 0.981, 95% CI [0.976, 0.986]), while a greater over time changes in BUN (OR = 1.034, 95% CI [1.029, 1.040]) and a smaller over time change in glucose (OR = 0.992, 95% CI [0.984, 0.999]) within 4 years were also related to a higher sarcopenia risk. LR based on significant blood factors (i.e., hsCRP, HbA1c, BUN, and glucose), and sarcopenia status in year 2015 yielded an area under the curve of 0.859 (95% CI: 0.836-0.882).

CONCLUSION

Routine blood factors involved in inflammation, protein metabolism, and glucose metabolism are significantly associated with sarcopenia. In clinical practice, plasma hsCRP, BUN, blood sugar levels, sex, age, marital status, height, and weight might be helpful for sarcopenia evaluation and monitoring.

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.

Muscle mass and chronic dizziness: a cross-sectional study of a Korean population

BACKGROUND AND OBJECTIVES

Weight gain is associated with imbalance in older people. In contrast, overweightness or mild obesity is less common in patients with chronic dizziness. This paradox may be, at least in part, related to differences in the body composition indices adopted in the previous studies. This study aimed to determine any association between the predicted body composition and chronic dizziness or imbalance of unknown causes.

METHODS

We measured the lean body mass, body fat mass, and appendicular skeletal mass in 9243 people who participated in the Korean National Health and Nutrition Examination Survey 2019-2021. Sarcopenia was defined according to the Asian Working Group for Sarcopenia's guidelines. Obesity was defined as a body fat percentage of ≥ 25% for men and ≥ 35% for women.

RESULTS

The participants with chronic dizziness had a lower body mass index than those without (p = 0.001). Furthermore, sarcopenia was more common in those with chronic dizziness. In contrast, the degree of obesity was comparable in both groups. Multiple logistic regression analysis showed that sarcopenia was associated with a higher risk of chronic dizziness (odds ratio = 1.6, 95% confidence interval: 1.1-2.5; p = 0.026).

DISCUSSION

Given the association of sarcopenia with chronic dizziness or imbalance, muscle mass may play a role in maintaining balance and stability. Physical exercise could be recommended to increase muscle mass in patients with chronic dizziness/imbalance and sarcopenia. Additional research is required to establish a causal relationship between chronic dizziness and sarcopenia.

Sensitivity and specificity of Yubi-wakka (finger-ring) screening method for sarcopenia among older Thai adults

AIM

The aim of this study was to validate a Yubi-wakka (finger-ring) test to identify older adults at risk for sarcopenia. Generally, measurements of muscle mass are considered to be a gold standard for testing for sarcopenia; such measurements are typically attained using bioelectrical impedance analysis (BIA) or dual-energy X-ray absorptiometry (DXA). However, the Yubi-wakka test is a simple assessment that can also be used to screen for sarcopenia.

METHODS

An analytic cross-sectional study was conducted to determine the sensitivity and specificity of the Yubi-wakka test. The study cohort included 230 adults older than 60 years who had no disabilities or handicaps and who visited the outpatient department of Phramongkutklao Hospital. Each participant underwent the Yubi-wakka test, a handgrip strength test, the 5-chair stand test, and BIA. We analyzed the associations between the Yubi-wakka test results and sarcopenia. The findings were compared with diagnoses that followed from the Asian Working Group for Sarcopenia 2019.

RESULTS

The test results were statistically associated with sarcopenia ("just fits" odds ratio [OR]: 8.55, 95% confidence interval [CI]: 3.29-22.18, and "smaller" OR: 10.73, 95% CI: 4.31-26.73, relative to "bigger"). The sensitivity and specificity of the Yubi-wakka test in men were 85.7% and 71.2% (area under the curve [AUC]: 0.785, 95% CI: 0.618-0.952), respectively. For women, the sensitivity and specificity of the test were 87.5% and 80.8% (AUC: 0.842, 95% CI: 0.764-0.919), respectively.

CONCLUSIONS

The Yubi-wakka test is a practical way of identifying the risk of sarcopenia among the elderly; it exhibits promising sensitivity and specificity. Geriatr Gerontol Int 2024; 24: 263-268.

Thigh muscle thickness on ultrasonography for diagnosing sarcopenia: The Kyoto-Kameoka study

AIM

The Asian Working Group for Sarcopenia 2019 consensus reported that evidence for the diagnosis of sarcopenia based on ultrasonography findings is lacking. The revised European Working Group on Sarcopenia in Older People consensus stated that ultrasonography is reliable and valid for assessing muscle size in older adults. The present study aimed to determine the predictive accuracy of ultrasonography for sarcopenia in older adults in Japan.

METHODS

A total of 1229 participants aged 65-91 years were included in this cross-sectional study. The thickness of the anterior compartment of the right thigh was assessed using B-mode ultrasonography. The measurement position was at the midpoint of the thigh. In addition, the grip strength, gait speed, Five-Time Sit-to-Stand Test, Short Physical Performance Battery score and skeletal muscle mass index were evaluated. Sarcopenia was diagnosed based on the Asian Working Group for Sarcopenia 2019 algorithm. We calculated the area under the receiver operating characteristic curve.

RESULTS

The area under the receiver operating characteristic curves (95% confidence intervals) and cutoff values for the thigh muscle thickness in sarcopenia were 0.901 (0.856-0.946) and 4.0 cm in men, respectively, and 0.923 (0.851-0.995) and 3.1 cm in women, respectively. The area under the receiver operating characteristic curve for each subdomain of sarcopenia, such as grip strength and gait speed, ranged from 0.618 to 0.872.

CONCLUSIONS

In the present study, the suggested cutoff mid-thigh muscle thicknesses on ultrasonography for predicting sarcopenia were 4.0 cm in men and 3.1 cm in women. Geriatr Gerontol Int 2024; 24: 156-161.

Global epidemiological features and impact of osteosarcopenia: A comprehensive meta-analysis and systematic review

Osteosarcopenia is defined as the concurrent occurrence of osteopenia/osteoporosis and sarcopenia. The aim of the current study was to perform a systematic review with meta-analysis to determine the global prevalence, risk factors and clinical outcomes of osteosarcopenia. This review was registered in PROSPERO (CRD42022351229). PubMed, Cochrane, Medline and Embase were searched from inception to February 2023 to retrieve eligible observational population-based studies. Pooled osteosarcopenia prevalence was calculated with 95% confidence interval (CI), and subgroup analyses were performed. The risk factor of osteosarcopenia and its association with clinical outcomes were expressed as odds ratio (OR) and hazard ratio (HR), respectively. Heterogeneity was estimated using the I2 test. Study quality was assessed using validated instruments matched to study designs. The search identified 55 158 studies, and 66 studies (64 404 participants, mean age from 46.6 to 93 years) were analysed in the final analysis, including 48 cross-sectional studies, 17 cohort studies and 1 case-control study. Overall, the pooled prevalence of osteosarcopenia was 18.5% (95% CI: 16.7-20.3, I2  = 98.7%), including 15.3% (95% CI: 13.2-17.4, I2  = 97.6%) in men and 19.4% (95% CI: 16.9-21.9, I2  = 98.5%) in women. The prevalence of osteosarcopenia diagnosed using sarcopenia plus osteopenia/osteoporosis was 20.7% (95% CI: 17.1-24.4, I2  = 98.55%), and the prevalence of using sarcopenia plus osteoporosis was 16.1% (95% CI: 13.3-18.9, I2  = 98.0%). The global osteosarcopenia prevalence varied in different regions with 22.9% in Oceania, 21.6% in Asia, 20.8% in South America, 15.7% in North America and 10.9% in Europe. A statistically significant difference was found in the subgroups of the study population between the hospital (24.7%) and community (12.9%) (P = 0.001). Frailty (OR = 4.72, 95% CI: 2.71-8.23, I2  = 61.1%), malnutrition (OR = 2.35, 95% CI: 1.62-3.40, I2  = 50.0%), female sex (OR = 5.07, 95% CI: 2.96-8.69, I2  = 73.0%) and higher age (OR = 1.10, 95% CI: 1.06-1.15, I2 ==86.0%) were significantly associated with a higher risk for osteosarcopenia. Meta-analysis of cohort studies showed that osteosarcopenia significantly increased the risk of fall (HR = 1.54, 95% CI: 1.20-1.97; I2  = 1.0%, three studies), fracture (HR = 2.13, 95% CI: 1.61-2.81; I2  = 67.8%, seven studies) and mortality (HR = 1.75, 95% CI: 1.34-2.28; I2  = 0.0%, five studies). Despite the heterogeneity arising from varied definitions and criteria, our findings highlight a significant global prevalence of osteosarcopenia and its negative impact on clinical health. Standardizing diagnostic criteria for osteosarcopenia would be advantageous in the future, and early detection and management should be emphasized in this patient population.

The aspartate aminotransferase to alanine aminotransferase ratio: A novel indicator for skeletal muscle mass in Chinese community adults

OBJECTIVES

The aspartate aminotransferase to alanine aminotransferase (AST/ALT) ratio, an indicator for liver fibrosis, could be easily detected in clinical practice. The aim of this study was to examine the association between the AST/ALT ratio and skeletal muscle mass among Chinese community adult residents.

METHODS

We enrolled 2644 participants, age ≥18 y, undergoing bioelectrical impedance analysis and liver function test. Univariate and multivariate logistic regression models were used to analyze the effect of the AST/ALT ratio on the presence of low muscle mass (LMM). Multiple linear regression analysis was used to assess the factors associated with the skeletal muscle mass index (SMI) and to construct a formula to calculate the SMI.

RESULTS

When the AST/ALT ratio was regarded as a categorical variable, AST/ALT quartiles 9-2.19) kept independent effects on the presence of LMM status. When it was regarded as a continuous variable, each unit of the AST/ALT ratio was significantly associated with a 49% (P < 0.01) augment of the prevalence of LMM. By multiple general linear regression analysis, the formula was constructed with an adjusted R2 of 0.72: SMI (kg/m2) = -0.14 AST/ALT ratio + 1.35 sex (male: 1; female: 0) + 0.72 overweight status (yes: 1; no: 0) - 0.14 age (≤65: 0; >65: 1) + 6.26.

CONCLUSION

In general, the high AST/ALT ratio was an independent adverse indicator of the presence of LMM.

Associations between Osteosarcopenia and Falls, Fractures, and Frailty in Older Adults: Results From the Canadian Longitudinal Study on Aging (CLSA)

OBJECTIVE

To explore if older adults with osteosarcopenia are at a greater risk of falls, fractures, frailty, and worsening life satisfaction and activities of daily living (ADL) compared to those with normal bone mineral density (BMD) and without sarcopenia.

DESIGN

The baseline and 3-year follow-up of a longitudinal study.

SETTING AND PARTICIPANTS

Community-dwelling people aged 65 years or older in Canada.

METHODS

Caucasian participants 65 years or older that completed the Canadian Longitudinal Study on Aging (CLSA) 2015 baseline interview, physical measurements and 3-year follow-up were included. Osteopenia/osteoporosis was defined as BMD T score below -1 SD according to the World Health Organization, and sarcopenia was defined as low grip strength and/or low gait speed according to the Sarcopenia Definition Outcomes Consortium. Osteosarcopenia was defined as the coexistence of osteopenia/osteoporosis and sarcopenia. Self-reported incident falls and fractures in the last 12 months before the 3-year follow-up were measured. Frailty was assessed through the Rockwood Frailty Index (FI); life satisfaction through the Satisfaction With Life Scale (SWLS); and ADL through the Older American Resources and Services modules. Multivariable logistic and linear regression, including subgroup analyses by sex, were conducted.

RESULTS

The sample of 8888 participants (49.1% females) had a mean age (SD) of 72.7 (5.6) years. At baseline, neither osteopenia/osteoporosis nor sarcopenia (reference group) was present in 30.1%, sarcopenia only in 18.4%, osteopenia/osteoporosis only in 29.2%, and osteosarcopenia in 22.3%. Osteosarcopenia was significantly associated with incident falls and fractures in males [adjusted odds ratio (aOR), 1.90, 95% CI 1.15, 3.14, and aOR 2.60, 95% CI 1.14, 5.91, respectively] compared to males without osteopenia/osteoporosis or sarcopenia. Participants with osteosarcopenia had worsening ADL of 0.110 (estimated β coefficient 0.110, 95% CI 0.029, 0.192) and a decrease in their SWLS by 0.660 (estimated β coefficient -0.660, 95% CI -1.133, -0.187), compared to those without. Osteosarcopenia was not associated with frailty for both males and females.

CONCLUSIONS AND IMPLICATIONS

Osteosarcopenia was associated with self-reported incident falls and fractures in males and worse life satisfaction and ADL for all participants. Assessing and identifying osteosarcopenia is essential for preventing falls and fractures. Furthermore, it improves life satisfaction and ADL.

Effectiveness of telehealth in preventive care: a study protocol for a randomised controlled trial of tele-exercise programme involving older people with possible sarcopenia or at risk of fall

BACKGROUND

Continuous loss of muscle mass and strength are the consequences of the ageing process, which increase the risk of falls among older people. Falls can lead to severe consequences such as bone fractures and hampered physical and psychological well-being. Regular exercise is the key to reversing muscle atrophy and relieving sarcopenia. However, the frailty of older people and the recent COVID-19 pandemic may affect their confidence to leave home to attend classes in the community. A feasible and effective alternative should be explored.

METHODS

The primary objective is to evaluate the effectiveness of tele-exercise (TE) in relation to physical functioning and exercise adherence among community-dwelling older people at risk of falls in comparison with a community-based group (CB). The secondary objective includes evaluating older people's experience with tele-exercise, emphasizing their psychological welfare, social well-being, and acceptance of the telehealth approach. The design, conduct, and report follow the SPIRIT guidelines (Standard Protocol Items: recommended items to address in a Clinical Trial Protocol and Related Documents). Older people will be recruited from 10 local community centres in Hong Kong and randomly allocated into two groups. All participants will attend the exercise training 3 days per week for 3 months but the mode of delivery will differ, either online as the tele-exercise group (TE) or face-to-face as the community-based group (CB). The outcome measures include muscle strength, physical function, exercise adherence and dropout rate, psychological and social well-being will be assessed at the baseline, and the 3rd, 6th and 12th month. Some participants will be invited to attend focus group interviews to evaluate their overall experience of the tele-exercise training.

DISCUSSION

Tele-exercise reduces the barriers to exercise, such as time constraints, inaccessibility to facilities, and the fear of frail older people leaving their homes. Promoting an online home-based exercise programme for older people can encourage them to engage in regular physical activity and increase their exercise adherence even when remaining at home. The use of telehealth can potentially result in savings in cost and time. The final findings will provide insights on delivering exercise via telehealth to older people and propose an exercise delivery and maintenance model for future practice.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ( https://www.chictr.org.cn/hvshowprojectEN.html?id=219002&v=1.1 ), registration number: ChiCTR2200063370. Registered on 5 September 2022.

Comparing the prognostic value of the old and new sarcopenia criteria from the Asian Working Group on Sarcopenia in older adults with type 2 diabetes: Which set is more appropriate?

BACKGROUND

This study aimed to compare the prevalence of sarcopenia according to the old and new Asian Working Group on Sarcopenia (AWGS) operational criteria and explore the effects of sarcopenia on adverse outcomes in older adults with type 2 diabetes (T2D).

METHODS

A total of 386 patients with T2D aged ≥ 60 years were recruited in retrospective cohort study. Sarcopenia was assessed with different versions of the AWGS consensus, including the AWGS2014, AWGS2019H (muscle mass adjusted for height), and AWGS2019B (muscle mass adjusted for body mass index). The median follow-up period was 47 months. The composite primary endpoint was the first occurrence of cardiovascular disease (CVD), fragility fracture, and all-cause mortality and the secondary outcomes included the three separate components of the primary outcome.

RESULTS

In this study, the prevalence of sarcopenia under different criteria was significantly different, with AWGS2019H having the highest prevalence of 31.3%. The agreement among sarcopenia criteria was unsatisfactory. By Cox regression analysis, all three AWGS definitions of sarcopenia were associated with the composite outcome of all-cause mortality, fracture and CVD (hazard ratio [HR], 2.69 vs. HR, 2.63; vs. HR, 2.23; model 3). Further exploratory analysis, sarcopenia defined by the AWGS2019H criteria was an independent risk factor for death, incident CVD, and fractures. While AWGS2014 criteria was an increased risk factor of death and CVD. The AWGS2019B criteria were only associated with incident fractures.

CONCLUSION

All three AWGS definitions of sarcopenia were associated the composite primary endpoint. Additionally, the AWGS2019H criteria may be a better independent risk factor for negative health outcomes.

TT3, a More Practical Indicator for Evaluating the Relationship Between Sarcopenia and Thyroid Hormone in the Euthyroid Elderly Compared with FT3

BACKGROUND AND AIMS

Sarcopenia is a common disease in the elderly, and the thyroid hormone (TH) might participate in the pathogenesis of sarcopenia. However, the results of previous studies were not completely consistent. We performed this study to investigate the association between THs and sarcopenia in a Chinese elderly euthyroid population.

SUBJECTS AND METHODS

A total of 309 Chinese elderly euthyroid subjects with an average age of 85.19 ± 7.8 years were enrolled. Participants were divided into four groups (non-sarcopenia, possible sarcopenia, sarcopenia and serve sarcopenia) according to the consensus update of AWGS in 2019. Serum levels of TT3, FT3, TT4, FT4, TSH, rT3 and TBG were measured. Muscle mass was measured by multifrequency bioelectrical impedance analysis, hand grip (HG) was represented by spring-type dynamometer, and gait speed (GS) was determined by 6-metre walk test. The FRAIL scale was used to assess frailty.

RESULTS

Compared to the non-sarcopenia group, the sarcopenia group showed a significant increase in age and FRIAL score, while FT3 and TT3 levels decreased significantly. Partial correlation analysis (adjusted by age, gender and the scores of FRIAL scale) indicated that FT3, TT3 and TSH had significant positive correlations with HG, and there also was a significant positive correlation between TT3 and GS. In addition, after adjusting for age, gender, BMI, ALT, sCr, and score on the FRAIL scale, the multivariate linear regression analysis showed that TT3 was positively associated with muscle strength and negatively associated with sarcopenia risk.

CONCLUSION

There is an association between the low TT3 level and sarcopenia. Therefore, maintaining higher T3 concentrations within the normal range appears to be beneficial for sarcopenia in the elderly. In addition, due to the fluctuation of FT3, TT3 is a more stable and practical indicator to evaluate the relationship between sarcopenia and thyroid hormone in the elderly euthyroid population.

Sex differences in skeletal muscle-aging trajectory: same processes, but with a different ranking

Sex differences in muscle aging are poorly understood, but could be crucial for the optimization of sarcopenia-related interventions. To gain insight into potential sex differences in muscle aging, we recruited young (23 ± 2 years, 13 males and 13 females) and old (80 ± 3.5 years, 28 males and 26 females) participants. Males and females in both groups were highly matched, and vastus lateralis muscle parameters of old versus young participants were compared for each sex separately, focusing on gene expression. The overall gene expression profiles separated the sexes, but similar gene expression patterns separated old from young participants in males and females. Genes were indeed regulated in the same direction in both sexes during aging; however, the magnitude of differential expression was sex specific. In males, oxidative phosphorylation was the top-ranked differentially expressed process, and in females, this was cell growth mediated by AKT signaling. Findings from RNA-seq data were studied in greater detail using alternative approaches. In addition, we confirmed our data using publicly available data from three independent human studies. In conclusion, top-ranked pathways differ between males and females, but were present and altered in the same direction in both sexes. We conclude that the same processes are associated with skeletal muscle aging in males and females, but the differential expression of those processes in old vs. young participants is sex specific.

Caloric Restriction Combined with Immobilization as Translational Model for Sarcopenia Expressing Key-Pathways of Human Pathology

The prevalence of sarcopenia is increasing while it is often challenging, expensive and time-consuming to test the effectiveness of interventions against sarcopenia. Translational mouse models that adequately mimic underlying physiological pathways could accelerate research but are scarce. Here, we investigated the translational value of three potential mouse models for sarcopenia, namely partial immobilized (to mimic sedentary lifestyle), caloric restricted (CR; to mimic malnutrition) and a combination (immobilized & CR) model. C57BL/6J mice were calorically restricted (-40%) and/or one hindleg was immobilized for two weeks to induce loss of muscle mass and function. Muscle parameters were compared to those of young control (4 months) and old reference mice (21 months). Transcriptome analysis of quadriceps muscle was performed to identify underlying pathways and were compared with those being expressed in aged human vastus lateralis muscle-biopsies using a meta-analysis of five different human studies. Caloric restriction induced overall loss of lean body mass (-15%, p<0.001), whereas immobilization decreased muscle strength (-28%, p<0.001) and muscle mass of hindleg muscles specifically (on average -25%, p<0.001). The proportion of slow myofibers increased with aging in mice (+5%, p<0.05), and this was not recapitulated by the CR and/or immobilization models. The diameter of fast myofibers decreased with aging (-7%, p<0.05), and this was mimicked by all models. Transcriptome analysis revealed that the combination of CR and immobilization recapitulated more pathways characteristic for human muscle-aging (73%) than naturally aged (21 months old) mice (45%). In conclusion, the combination model exhibits loss of both muscle mass (due to CR) and function (due to immobilization) and has a remarkable similarity with pathways underlying human sarcopenia. These findings underline that external factors such as sedentary behavior and malnutrition are key elements of a translational mouse model and favor the combination model as a rapid model for testing the treatments against sarcopenia.

Sarcopenia and osteosarcopenia among patients undergoing hemodialysis

Background

Sarcopenia and osteoporosis are closely interconnected and associated with adverse health outcomes. Osteosarcopenia is the concurrent presence of the two conditions and has rarely been reported in hemodialysis patients. Whether hemodialysis patients with osteosarcopenia are at greater risk of mortality than those with either condition alone remains unknown. The aim of this study was to explore the prevalence of sarcopenia and its association with osteoporosis and to determine its impact on survival risk in hemodialysis patients.

Methods

A total of 209 adults undergoing hemodialysis were enrolled from the dialysis center in the West China Hospital of Sichuan University, and our study was registered at the Chinese Clinical Trial Register (number: ChiCTR2100043932). Muscle mass, handgrip strength, bone mineral density (BMD), and biochemical parameters were assessed. All deaths were recorded during a follow-up of 35.15 ± 15.37 months.

Results

Seventy-eight patients were diagnosed with sarcopenia, with a prevalence of 37.3%. After adjustment for potential confounders, age (OR=1.094, P <0.001), female sex (OR= 3.44, P =0.005), diabetes (OR=3.756, P =0.008), CRP (OR=1.09, P =0.015), serum magnesium (OR=0.755, p=0.042) and BMI (OR=0.701, P <0.001) were independently associated with sarcopenia. Among the 209 patients, 103 patients completed the BMD assessment. The prevalence of osteosarcopenia was 22.3%, while 20.4% of participants had sarcopenia alone and 12.6% had osteoporosis alone. The proportions of patients who died were 13.0% for nonsarcopenia&nonosteoporosis, 15.4% for osteoporosis alone, 47.6% for sarcopenia alone, and 52.2% for osteosarcopenia. Cox regression analysis showed that osteosarcopenia was independently associated with all-cause mortality (HR=3.74, 95% CI: 1.172-11.938), while osteoporosis alone and sarcopenia alone were not.

Conclusion

Patients undergoing hemodialysis had a high incidence of sarcopenia and osteosarcopenia, muscle mass and strength showed a significant association with BMD, and osteosarcopenia might have a powerful impact on mortality in those patients.

Clinical trial registration

http://www.chictr.org.cn/, identifier ChiCTR2100043932.

Cancer Cell-Extrinsic Roles for the Androgen Receptor in Prostate Cancer

Given the central role of the androgen receptor (AR) in prostate cancer cell biology, AR-targeted therapies have been the backbone of prostate cancer treatment for over 50 years. New data indicate that AR is expressed in additional cell types within the tumor microenvironment. Moreover, targeting AR for the treatment of prostate cancer has established side effects such as bone complications and an increased risk of developing cardiometabolic disease, indicating broader roles for AR. With the advent of novel technologies, such as single-cell approaches and advances in preclinical modeling, AR has been identified to have clinically significant functions in other cell types. In this mini-review, we describe new cancer cell-extrinsic roles for AR within the tumor microenvironment as well as systemic effects that collectively impact prostate cancer progression and patient outcomes.

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.

The association between paraspinal muscle parameters and vertebral pedicle microstructure in patients undergoing lumbar fusion surgery

PURPOSE

Lumbar fusion surgery has become a standard procedure in spine surgery and commonly includes the posterior placement of pedicle screws. Bone quality is a crucial factor that affects pedicle screw purchase. However, the relationship between paraspinal muscles and the bone quality of the pedicle is unknown. The aim of the study was to determine the relationship between paraspinal muscles and the ex vivo bony microstructure of the lumbar pedicle.

METHODS

Prospectively, collected data of patients undergoing posterior lumbar fusion for degenerative spinal conditions was analyzed. Pre-operative lumbar magnetic resonance imaging (MRI) scans were evaluated for a quantitative assessment of the cross-sectional area (CSA), functional cross-sectional area (fCSA), and the proportion of intramuscular fat (FI) for the psoas muscle and the posterior paraspinal muscles (PPM) at L4. Intra-operative bone biopsies of the lumbar pedicle were obtained and analyzed with microcomputed tomography (µCT) scans. The following cortical (Cort) and trabecular (Trab) bone parameters were assessed: bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), connectivity density (CD), bone-specific surface (BS/BV), apparent density (AD), and tissue mineral density (TMD).

RESULTS

A total of 26 patients with a mean age of 59.1 years and a mean BMI of 29.8 kg/m2 were analyzed. fCSAPPM showed significant positive correlations with BV/TVTrab (ρ = 0.610; p < 0.001), CDTrab (ρ = 0.679; p < 0.001), Tb.NTrab (ρ = 0.522; p = 0.006), Tb.ThTrab (ρ = 0.415; p = 0.035), and ADTrab (ρ = 0.514; p = 0.007). Cortical bone parameters also demonstrated a significant positive correlation with fCSAPPM (BV/TVCort: ρ = 0.584; p = 0.002; ADCort: ρ = 0.519; p = 0.007). FIPsoas was negatively correlated with TMDCort (ρ =  - 0.622; p < 0.001).

CONCLUSION

This study highlights the close interactions between the bone microstructure of the lumbar pedicle and the paraspinal muscle morphology. These findings give us further insights into the interaction between the lumbar pedicle microstructure and paraspinal muscles.

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.

Does wing use and disuse cause behavioural and musculoskeletal changes in domestic fowl (Gallus gallus domesticus)?

Domestic chickens may live in environments which restrict wing muscle usage. Notably, reduced wing activity and accompanying muscle weakness are hypothesized risk factors for keel bone fractures and deviations. We used radio-frequency identification (RFID) to measure duration spent at elevated resources (feeders, nest-boxes), ultrasonography to measure muscle thickness (breast and lower leg) changes, radiography and palpation to determine fractures and deviations, respectively, following no, partial (one-sided wing sling) and full (cage) immobilization in white- and brown-feathered birds. We hypothesized partially immobilized hens would reduce elevated resource usage and that both immobilization groups would show decreased pectoralis thickness (disuse) and increased prevalence of fractures and deviations. Elevated nest-box usage was 42% lower following five weeks of partial immobilization for brown-feathered hens but no change in resource usage in white-feathered birds was observed. Fully immobilized, white-feathered hens showed a 17% reduction in pectoralis thickness, while the brown-feathered counterparts showed no change. Lastly, fractures and deviations were not affected in either strain or form of wing immobilization; however, overall low numbers of birds presented with these issues. Altogether, this study shows a profound difference between white- and brown-feathered hens in response to wing immobilization and associated muscle physiology.

The combination of osteoporosis and low lean mass correlates with physical function in end-stage knee osteoarthritis: A retrospective observational study

We aimed to investigate the prevalence of osteoporosis and low lean mass, either together or in isolation, and their association with physical function, pain, and quality of life (QOL) in patients with end-stage knee osteoarthritis (OA). This retrospective cross-sectional observational study included 578 patients (77 males and 501 females) diagnosed with end-stage knee OA. Patients were divided into 4 groups based on body composition parameters: control, osteoporosis, low lean mass, and osteoporosis + low lean mass. All participants underwent performance-based physical function tests, including a stair climbing test (SCT), a 6-minute walk test, a timed up and go test, and instrumental gait analysis, to examine spatiotemporal parameters. Self-reported physical function and pain levels were measured using the Western Ontario McMaster Universities Osteoarthritis Index and visual analog scale, respectively. Self-reported QOL was measured using the EuroQOL 5 dimensions (EQ-5D) questionnaire. Of 578 patients, 268 (46.4%) were included in the control group, 148 (25.6%) in the osteoporosis group, 106 (18.3%) in the low lean mass group, and 56 (9.7%) in the osteoporosis + low lean mass group. Analysis of variance revealed that the scores for the osteoporosis + low lean mass group in the SCT-ascent, SCT-descent, and timed up and go test were significantly higher, whereas those for the 6-minute walk test, gait speed, and cadence were significantly lower than those for the other groups (P < .05). After adjusting for age, sex, and body mass index, multiple linear regression analysis identified SCT-ascent (β = 0.140, P = .001, R2 = 0.126), SCT-descent (β = 0.182, P < .001, R2 = 0.124), gait speed (β = -0.116, P = .005, R2 = 0.079), and cadence (β = -0.093, P = .026, R2 = 0.031) as being significantly associated with osteoporosis + low lean mass. Thus, osteoporosis + low lean mass correlates with poor physical function, but not pain and QOL, in patients with end-stage knee OA.

Inhibiting uptake of extracellular vesicles derived from senescent bone marrow mesenchymal stem cells by muscle satellite cells attenuates sarcopenia

Objective

Osteoporosis is associated with senescence of bone marrow mesenchymal stem cells (BMSCs). Extracellular vesicles derived from senescent BMSCs (BMSC-EVs) could be uptaken by muscle satellite cells (SCs). We hypothesized that inhibiting the uptake of harmful BMSC-EVs by SCs could prevent patients with osteoporosis complicated with sarcopenia.

Methods

Bioinformatics analysis was used to analyze senescent SCs. Myogenic potential of SCs was measured using myogenesis assay and immunofluorescence while muscle atrophy was measured using histological evaluation. And the interaction of cluster of differentiation (CD) 81 and the membrane proteins of SCs was verified using biotin pulldown assay.. CD81-specific siRNA (si-CD81) was used to knockdown CD81 and anti-CD81 antibody (anti-CD81 Ab) was used to block CD81.

Results

Differentially expressed genes in senescent SCs were enriched in muscle cell differentiation. The myogenic potential of senescent SCs was significantly decreased. Senescent BMSC-EVs impaired myogenesis of SCs. CD81 on the surface of BMSC-EVs could bind to membrane proteins of SCs. Both knockdown of CD81 and blocking CD81 prevented the uptake of senescent BMSC-EVs by SCs, thus relieving harmful effects of senescent BMSC-EVs on muscle atrophy.

Conclusion

Blocking CD81 on the surface of senescent BMSC-EVs attenuates sarcopenia in aged mice, which could be useful for prevention of sarcopenia in patients with osteoporosis in clinical practice.

Translational potential of this article

Inhibiting uptake of extracellular vesicles derived from senescent bone marrow mesenchymal stem cells by muscle satellite cells can prevent muscle atrophy in aged mice and has potential for application in treating sarcopenia.

HR-pQCT for the Evaluation of Muscle Quality and Intramuscular Fat Infiltration in Ageing Skeletal Muscle

Myosteatosis is the infiltration of fat in skeletal muscle during the onset of sarcopenia. The quantification of intramuscular adipose tissue (IMAT) can be a feasible imaging modality for the clinical assessment of myosteatosis, important for the early identification of sarcopenia patients and timely intervention decisions. There is currently no standardized method or consensus for such an application. The aim of this study was to develop a method for the detection and analysis of IMAT in clinical HR-pQCT images of the distal tibia to evaluate skeletal muscle during the ageing process, validated with animal and clinical experimentation. A pre-clinical model of ovariectomized (OVX) rats with known intramuscular fat infiltration was used, where gastrocnemii were scanned by micro-computed tomography (micro-CT) at an 8.4 μm isotropic voxel size, and the images were analyzed using our modified IMAT analysis protocol. IMAT, muscle density (MD), and muscle volume (MV) were compared with SHAM controls validated with Oil-red-O (ORO) staining. Furthermore, the segmentation and IMAT evaluation method was applied to 30 human subjects at ages from 18 to 81 (mean = 47.3 ± 19.2). Muscle-related parameters were analyzed with functional outcomes. In the animal model, the micro-CT adipose tissue-related parameter of IMAT% segmented at −600 HU to 100 HU was shown to strongly associate with the ORO-positively stained area (r = 0.898, p = 0.002). For the human subjects, at an adjusted threshold of −600 to −20 HU, moderate positive correlations were found between MV and MD (r = 0.642, p < 0.001), and between MV and IMAT volume (r = 0.618, p < 0.01). Moderate negative correlations were detected between MD and IMAT% (r = −0.640, p < 0.001). Strong and moderate associations were found between age and MD (r = −0.763, p < 0.01), and age and IMAT (r = 0.559, p < 0.01). There was also a strong correlation between IMAT% and chair rise time (r = 0.671, p < 0.01). The proposed HR-pQCT evaluation protocol for intramuscular adipose-tissue produced MD and IMAT results that were associated with age and physical performance measures, and were of good predictive value for the progression of myosteatosis or sarcopenia. The protocol was also validated on animal skeletal muscle samples that showed a good representation of histological lipid content with positive correlations, further supporting the clinical application for the rapid evaluation of muscle quality and objective quantification of skeletal muscle at the peripheral for sarcopenia assessment.

Associations of geriatric nutrition risk index and other nutritional risk-related indexes with sarcopenia presence and their value in sarcopenia diagnosis

Objective

Standard modalities recommended for sarcopenia diagnosis may be unavailable in primary care settings. We aimed to comprehensively evaluate and compare associations of some better popularized nutritional risk-related indexes with sarcopenia presence and their value in sarcopenia diagnosis in community-dwelling middle-aged and elderly adults, including geriatric nutrition risk index (GNRI), albumin (ALB), calf circumference (CC), mid-arm circumference (MAC), triceps skinfold thickness (TST) and body mass index (BMI).

Methods

Based on the West China Health and Aging Trend study, the current study included participants aged 50 or older who were recruited in 2018. Sarcopenia-related assessment and diagnosis were in line with Asian Working Group for Sarcopenia 2019. For each single index, we assessed its association with sarcopenia presence by univariate and multivariate logistic regression analysis; we also computed diagnostic measures including the area under the receiver operating characteristic curve (AUC) and sensitivity, specificity, accuracy at the optimal cut-off value determined according to Youden’s index.

Results

A total of 3829 subjects were included, consisting of 516 and 3313 subjects in the sarcopenia and non-sarcopenia groups, respectively. Regarding the risk for sarcopenia presence, the fully adjusted odds ratios of GNRI, ALB, CC, MAC, TST and BMI per standard deviation decrease were 2.95 (95% CI 2.51–3.47, P < 0.001), 1.01 (95% CI 0.90–1.15, P = 0.816), 4.56 (95% CI 3.82–5.44, P < 0.001), 4.24 (95% CI 3.56–5.05, P < 0.001), 1.67 (95% CI 1.92–1.45, P < 0.001) and 4.09 (95% CI 3.41–4.91, P < 0.001), respectively. Regarding the value in sarcopenia diagnosis in the entire study population, their AUCs could be ordered as MAC (0.85, 95% CI 0.83–0.86) > GNRI (0.80, 95% CI 0.78–0.82), CC (0.83, 95% CI 0.81–0.85), BMI (0.81, 95% CI 0.79–0.83) > TST (0.72, 95% CI 0.70–0.74) > ALB (0.62, 95% CI 0.60–0.65). At the relevant optimal cut-off values, the sensitivity was the highest for CC (0.83, 95% CI 0.80–0.87) and MAC (0.80, 95% CI 0.77–0.84), while GNRI showed the highest specificity (0.79, 95% CI 0.78–0.81) and accuracy (0.78, 95% 0.76–0.79).

Conclusion

Overall diagnostic performance was the best for MAC, followed by GNRI, CC, BMI, and the worst for TST, ALB in distinguishing sarcopenia from non-sarcopenia in middle-aged and elderly adults in community-based settings. CC or MAC might do better in reducing missed diagnosis, while GNRI was superior in reducing misdiagnosis.

Association between Elevated Plasma Homocysteine and Low Skeletal Muscle Mass in Asymptomatic Adults

BACKGROUND

Homocysteine has been drawing attention with a closed linkage with skeletal muscle. However, the association of hyperhomocysteinemia with decreased skeletal muscle mass remains unclear. We aimed to investigate the association of hyperhomocysteinemia with low skeletal muscle mass (LMM) in asymptomatic adults.

METHODS

This was a cross-sectional study of 114,583 community-dwelling adults without cancer, stroke, or cardiovascular diseases who underwent measurements of plasma homocysteine and body composition analysis from 2012 to 2018. Hyperhomocysteinemia was defined as >15 μmol/L. Skeletal muscle mass index (SMI) was calculated based on appendicular muscle mass (kg)/height (m)2. Participants were classified into three groups based on SMI: "normal," "mildly low," and "severely low."

RESULTS

The prevalence of hyperhomocysteinemia was the highest in subjects with severely LMM (12.9%), followed by those with mildly LMM (9.8%), and those with normal muscle mass (8.5%) (P for trend <0.001). In a multivariable logistic regression model, hyperhomocysteinemia was significantly associated with having a mildly LMM (odds ratio [OR], 1.305; 95% confidence interval [CI], 1.224 to 1.392) and severely LMM (OR, 1.958; 95% CI, 1.667 to 2.286), respectively. One unit increment of log-transformed homocysteine was associated with 1.360 and 2.169 times higher risk of having mildly LMM and severely LMM, respectively.

CONCLUSION

We demonstrated that elevated homocysteine has an independent association with LMM in asymptomatic adults, supporting that hyperhomocysteinemia itself can be a risk for decline in skeletal musculature.

Muscle Strength and Physical Performance Improve Fracture Risk Prediction Beyond Garvan and FRAX: The Osteoporotic Fractures in Men (MrOS) Study

Muscle strength and physical performance are associated with fracture risk in men. However, it is not known whether these measurements enhance fracture prediction beyond Garvan and FRAX tools. A total of 5665 community-dwelling men, aged ≥65 years, from the Osteoporotic Fractures in Men (MrOS) Study, who had data on muscle strength (grip strength) and physical performance (gait speed and chair stand tests), were followed from 2000 to 2019 for any fracture, major osteoporotic fracture (MOF), initial hip, and any hip fracture. The contributions to different fracture outcomes were assessed using Cox's proportional hazard models. Tool-specific analysis approaches and outcome definitions were used. The added predictive values of muscle strength and physical performance beyond Garvan and FRAX were assessed using categorical net reclassification improvement (NRI) and relative importance analyses. During a median follow-up of 13 (interquartile range 7-17) years, there were 1014 fractures, 536 MOFs, 215 initial hip, and 274 any hip fractures. Grip strength and chair stand improved prediction of any fracture (NRI for grip strength 3.9% and for chair stand 3.2%) and MOF (5.2% and 6.1%). Gait speed improved prediction of initial hip (5.7%) and any hip (7.0%) fracture. Combining grip strength and the relevant performance test further improved the models (5.7%, 8.9%, 9.4%, and 7.0% for any, MOF, initial, and any hip fractures, respectively). The improvements were predominantly driven by reclassification of those with fracture to higher risk categories. Apart from age and femoral neck bone mineral density, muscle strength and performance were ranked equal to or better than the other risk factors included in fracture models, including prior fractures, falls, smoking, alcohol, and glucocorticoid use. Muscle strength and performance measurements improved fracture risk prediction in men beyond Garvan and FRAX. They were as or more important than other established risk factors. These measures should be considered for inclusion in fracture risk assessment tools. © 2021 American Society for Bone and Mineral Research (ASBMR).

Diagnosis and Management of Sarcopenia after Hip Fracture Surgery: Current Concept Review

To date, family medicine and internal medicine fields have been responsible for defining, researching, and development of treatments for sarcopenia, focusing mainly on diabetes and metabolic diseases. Therefore, application of current guidelines for diagnosis of sarcopenia which differ according to continent to patients with hip fractures in the orthopedic field is difficult. The purpose of this review was to understand the recent consensus on the definition and diagnosis of sarcopenia and to highlight the importance of research and future research opportunities on the management of sarcopenia in patients with hip fractures by orthopedic surgeons. The global prevalence of sarcopenia in patients with hip fractures is statistically significant. Despite establishment of various therapeutic and diagnostic criteria for osteoporosis in the clinical field, there are no clear, useful diagnostic criteria for sarcopenia in the clinical field. In particular, few studies on the evaluation and treatment of sarcopenia in patients with hip fractures have been reported. In addition, the quality of life of postoperative patients with hip fractures could be significantly improved by development of precise assessment for muscle regeneration and rehabilitation in the operating room.

Basolateral Amygdala Mediates Central Mechanosensory Feedback of Musculoskeletal System

Musculoskeletal diseases, such as osteoporosis and sarcopenia, are tremendous and growing public health concerns. Considering the intimate functional relationship between muscle and bone throughout development, growth, and aging, muscle provides the primary source of skeletal loading through contraction force. However, significant gaps exist in our knowledge regarding the role of muscle in bone homeostasis and little is known regarding the mechanism through which the central nervous system responds and regulates unloading-induced bone loss. Here, we showed that the basolateral amygdala (BLA) and medial part of the central nucleus (CeM) are anatomically connected with the musculoskeletal system. Unloading-induced bone loss is accompanied by a decrease in serum semaphorin 3A (Sema3A) levels as well as sensory denervation. In vivo fiber photometry recordings indicated that the mechanical signal is integrated by the BLA and CeM within 24 h and subsequently regulates bone remodeling. Moreover, chemogenetic activation of BLA^CaMKII neurons mitigates severe bone loss caused by mechanical unloading via increased serum levels of Sema3A and sensory innervation. These results indicate that the BLA integrates the mechanosensory signals rapidly and mediates the systemic hormonal secretion of Sema3A to maintain bone homeostasis.

The association of cardio-metabolic risk factors and history of falling in men with osteosarcopenia: a cross-sectional analysis of Bushehr Elderly Health (BEH) program

Background

Osteosarcopenia, defined as sarcopenia plus osteopenia/osteoporosis, may increase the risk of fractures and affects morbidity and mortality in the older population. Falling is also common in the elderly and increases the risk of fractures and mortality. We examined the association of cardio-metabolic risk factors with a history of falling in osteosarcopenic men.

Methods

We used the baseline data of the Bushehr Elderly Health (BEH) program. Osteosarcopenia was defined as having both sarcopenia (reduced skeletal muscle mass plus low physical performance and/or low muscle strength) and osteopenia/osteoporosis (T-score ≤ − 1.0). Falling was defined as a self-reported history of an unintentional down on the ground during the previous year before the study. We used logistic regression analysis to estimate the adjusted odds ratio (AOR) with a 95% Confidence Interval (CI) to quantify the associations.

Results

All elderly men diagnosed with osteosarcopenia (n = 341), with a mean age of 73.3(±7.4) years, were included. Almost 50(14.7%) participants reported falling. Age showed a positive association with falling (AOR: 1.09, 95%CI: 1.04–1.14). An increase of 10 mmHg in systolic blood pressure(SBP), reduces the odds of falling by 26%(AOR:0.74, 95%CI:0.62–0.89), while a positive association was detected for fasting plasma glucose (FPG), as 10 mg/dl increase in the FPG, raises the chance of falling by 14%(AOR = 1.14, 95%CI:1.06,1.23). Hypertriglyceridemia was inversely associated with falling (AOR = 0.33, 95% CI: 0.12, 0.89).

Conclusions

Falling is a major public health problem in rapidly aging countries, especially in individuals with a higher risk of fragility fractures. Older age-raised fasting plasma glucose and low SBP are associated with falling in osteosarcopenic patients. 

Considering the higher risk of fracture in osteosarcopenic men, comprehensive strategies are needed to prevent fall-related injuries in this high-risk population.

Physical activities mediate the correlations between serum creatinine and bone mineral density in Chinese

BACKGROUND

The relationship between serum creatinine (CR) and osteoporosis under normal renal function and the possible mediating effects mediated by physical activity (PA) are largely unknown.

METHODS

A total of 4,137 elderly Chinese subjects were recruited. Three models including different covariates were established. Correlation analysis and multiple linear regression analysis were used to evaluate the relationship between CR and bone mineral density (BMD) and also under different PA pattern. Logistic regression was used to investigate the interaction between CR*PA with osteoporosis. PA was used as a moderating variable to investigate the relationship between CR and BMD.

RESULTS

As we expected, the association between CR and BMD remained significant after adjusting covariates in all models. The relationship between CR and BMD showed changeable pattern in case of different physical activity. Specially, the moderating effects of PA on serum creatinine and BMD were significant for all models only in the case of medium physical activity (PA3).

CONCLUSIONS

In Chinese elderly under normal renal function, serum CR is positively correlated with BMD, and medium physical activity has mediation effect on such correlation.

A Prediction Modeling Based on the Hospital for Special Surgery (HSS) Knee Score for Poor Postoperative Functional Prognosis of Elderly Patients with Patellar Fractures

Background

The main aim of this study was to develop a nomogram prediction model for poor functional prognosis after patellar fracture surgery in the elderly based on the hospital for special surgery (HSS) knee score.

Methods

A retrospective analysis of 168 elderly patients with patellar fractures was performed to collect demographic data, knee imaging, and functional prognosis preoperatively and during the 6-month postoperative follow-up period. Good functional prognosis of knee joint was defined as the percentage of HSS knee scores on the injured side relative to the uninjured side ≥ 80% at six-month postoperative review. Multifactorial linear regression analysis and logistic regression analysis were then used to identify risk factors of functional prognosis and develop the nomogram prediction model. Furthermore, the validity and accuracy of the prediction model were evaluated using C-index, area under the curve (AUC), and decision curve analyses.

Results

The final screening from the 12 potential risk factors yielded three high-risk factors which were included in the nomogram prediction model: advanced age (OR 0.28 (95% CI 0.11-0.67), P = 0.005), sarcopenia (OR 0.11 (95% CI 0.05-0.26), P < 0.001), and low albumin level (OR 1.14 (95% CI 1.02-1.29), P = 0.025). The model had a good predictive ability with an AUC of 0.857 (95% CI (0.783-0.929)) for the training group and a C-index of 0.836 for the overall sample. In addition, the decision analysis curve indicated that the model had good clinical applicability.

Conclusion

Our predictive model is effective in predicting the risk of poor functional prognosis after patellar fracture surgery in the elderly by assessing high-risk factors such as advanced age, sarcopenia, and serum albumin levels. This prediction model can help clinicians to make individualized risk prediction, early identification of patients at high risk for poor functional outcome, and appropriate interventions.

Mitochondrial Quality Control in Sarcopenia: Updated Overview of Mechanisms and Interventions

Sarcopenia is a common geriatric disorder characterized by decreased muscle strength, low muscle mass and poor physical performance. This aging-related skeletal muscle deterioration leads to adverse outcomes and severely impairs the quality of life of patients. The accumulation of dysfunctional mitochondria with aging is an important factor in the occurrence and progression of sarcopenia. Mitochondrial quality control (MQC) fundamentally ensures the normal mitochondrial functions and is comprised of four main parts: proteostasis, biogenesis, dynamics and autophagy. Therefore, any pathophysiologic factors compromising the quality control of homeostasis in the skeletal muscle may lead to sarcopenia. However, the specific theoretical aspects of these processes have not been fully elucidated. Current therapeutic interventions using nutritional and pharmaceutical treatments show a modest therapeutic efficacy; however, only physical exercise is recommended as the first-line therapy for sarcopenia, which can ameliorate skeletal muscle deficiency by maintaining the homeostatic MQC. In this review, we summarized the known mechanisms that contribute to the pathogenesis of sarcopenia by impairing normal mitochondrial functions and described potential interventions that mitigate sarcopenia through improving MQC.

Diagnosis of sarcopenia by evaluating skeletal muscle mass by adjusted bioimpedance analysis validated with dual-energy X-ray absorptiometry

BACKGROUND

This study aimed to adjust and cross-validate skeletal muscle mass measurements between bioimpedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) for the screening of sarcopenia in the community and to estimate the prevalence of sarcopenia in Hong Kong.

METHODS

Screening of sarcopenia was provided to community-dwelling older adults. Appendicular skeletal muscle mass (ASM) was evaluated by BIA (InBody 120 or 720) and/or DXA. Handgrip strength and/or gait speed were assessed. Diagnosis of sarcopenia was based on the 2019 revised Asian Working Group for Sarcopenia cut-offs. Agreement analysis was performed to cross-validate ASM measurements by BIA and DXA. Multiple regression was used to explore contribution of measured parameters in predicting DXA ASM from BIA.

RESULTS

A total of 1587 participants (age = 72 ± 12 years) were recruited; 1065 participants were screened by BIA (InBody 120) with 18 followed up by DXA, while the remaining 522 participants were assessed by the BIA (InBody 720) and DXA. The appendicular skeletal muscle mass index (ASMI) evaluated by BIA showed a mean difference of 2.89 ± 0.38 kg/m² (InBody 120) and 2.97 ± 0.45 kg/m² (InBody 720) against DXA gold standard. A significant overestimation of muscle mass was measured by BIA compared with DXA (P < 0.005). BIA data were adjusted using prediction equation and mean difference reduced to -0.02 ± 0.31 kg/m² in cross-validation. Prevalence of sarcopenia in older adults ≥65 ranged from 39.4% (based on ASMI by DXA) to 40.8% (based on predicted DXA ASMI from BIA). Low ASMI by DXA was found in 68.5% of the older adults screened. The percentage of older adults exhibited low handgrip strength ranged from 31.3% to 56%, while 49% showed low gait speed.

CONCLUSIONS

Bioimpedance analysis was found to overestimate skeletal muscle mass compared with DXA. With adjustment equations, BIA can be used as a quick and reliable tool for screening sarcopenia in community and clinical settings with limited access to better options.

Bone Microarchitecture Decline and Risk of Fall and Fracture in Men With Poor Physical Performance-The STRAMBO Study

CONTEXT

High fracture risk in individuals with low muscle strength is attributed to high risk of falls.

OBJECTIVE

This work aims to study the association of muscle mass and physical performance with bone microarchitecture decline and risk of fall and nonvertebral fracture in men.

METHODS

A prospective, 8-year follow-up of a cohort was conducted among the general population. A total of 821 volunteer men aged 60 and older participated. Hip areal bone mineral density (aBMD) and appendicular lean mass (ALM) were assessed at baseline by dual x-ray absorptiometry. Lower-limb relative ALM (RALM-LL) is ALM-LL/(leg length)2. The physical performance score reflects the ability to perform chair stands and static and dynamic balance. Bone microarchitecture was assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) at baseline and after 4 and 8 years. Statistical analyses were adjusted for shared risk factors. Outcome measurements included the rate of change in the HR-pQCT indices, incident falls, and fractures.

RESULTS

Cortical bone loss and estimated bone strength decline were faster in men with low vs normal RALM-LL (failure load: -0.74 ± 0.09 vs -0.43 ± 0.10%/year; P < .005). Differences were similar between men with poor and those with normal physical performance (failure load: -1.12 ± 0.09 vs -0.40 ± 0.05%/year; P < .001). Differences were similar between men having poor performance and low RALM-LL and men having normal RALM-LL and performance (failure load: -1.40 ± 0.17 vs -0.47 ± 0.03%/year; P < .001). Men with poor physical performance had a higher risk of fall (hazard ratio [HR] = 3.52; 95% CI, 1.57-7.90, P < .05) and fracture (HR = 2.68; 95% CI, 1.08-6.66, P < .05).

CONCLUSION

Rapid decline of bone microarchitecture and estimated strength in men with poor physical performance and low RALM-LL may contribute to higher 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.

Bibliometric analysis of global research trends on male osteoporosis: a neglected field deserves more attention

We analyzed the knowledge structure, current status, and future directions of 3243 publications on male osteoporosis by employing bibliometric analysis. Our results indicated that Osteoporosis International was the most influential journal in this field. And the study of epidemiology and risk factors has been recognized as a hot research topic in recent years. This study also calls for more attention to be given on male osteoporosis research.

INTRODUCTION

Male osteoporosis is increasing as a serious health problem worldwide with the aging of population. However, a comprehensive understanding of the current status and future trends in this field is lacking to date. The goal of the present study was to summarize and visualize the knowledge framework, research hotspots, and emerging trends of male osteoporosis research based on the bibliometric method.

METHODS

Scientific publications regarding male osteoporosis from 1998 to 2020 were downloaded from the SCIE database. VOSviewer, CiteSpace, and online bibliometric website were used for this study. The main analyses include cooperative relationships between countries/institutions/authors, co-citation analysis of authors/journals, and co-occurrence analysis of keywords/subject categories, as well as analyses on keyword/reference bursts.

RESULTS

A total of 3243 publications with 128,751 citations were identified. Despite experiencing a period of increase in the number of publications, incentives for conducting male osteoporosis research seem to have decreased during recent years. The USA has the most prominent contributions, as reflected by most publications and the highest H-index value. Oregon Health and Science University was the most prolific institution within this domain. The most influential academic journal was Osteoporosis International. Keywords were categorized into four clusters: basic research, epidemiology and risk factors, diagnostic studies, treatment and fracture prevention. Burst keyword detection suggested that the following research directions including "obesity," "zoledronic acid," "DXA," "inflammation," "fall," "microarchitecture," and "sarcopenia" remain research hotspots in the near future and deserve our further attention.

CONCLUSIONS

This is the first bibliometric analysis that provides a comprehensive overview of male osteoporosis research, which may provide helpful references for investigators to further explore hot issues in this field.

Association of green space with bone mineral density change and incident fracture in elderly Hong Kong Chinese: Mr. OS and Ms. OS study

BACKGROUND

A large body of literature has reported positive effects of green space (GS) on various aspects of health and well-being, while no studies explore the role of GS in bone health.

OBJECTIVES

The present study aimed to investigate the associations of GS with bone mineral density (BMD) change and incident fracture in a prospective cohort of elderly Hong Kong Chinese.

METHODS

Between 2001 and 2003, 3944 participants aged 65 years and older at baseline were recruited. GS (%) within 300-m and 500-m buffers were calculated for each participant based on the Normalized Difference Vegetation Index. BMD at whole body, lumbar spine, total hip, and femoral neck were assessed by dual energy X-ray absorptiometry at baseline and 3 follow-ups. Incident fracture cases were ascertained from the electronic database of Hospital Authority of Hong Kong. Linear mixed-effects models and Cox proportional hazards models were used to investigate the associations of GS with changes in BMD and incident fracture, respectively.

RESULTS

Greater GS within 300-m and 500-m buffers were associated with a slower increase in lumbar spine BMD over 14 years. After adjustment for potential confounders, β and 95% confidence intervals (CIs) of change in BMD across Q2-Q4 (quartiles of GS measured in a 300-m, compared with Q1) were -6.42 (-12.3, -0.59), -7.78 (-13.6, -1.97), and -7.83 (-13.7, -2.00) mg/cm³, respectively. GS was also positively associated with non-spinal fracture and major osteoporotic fracture incidence risks. Multivariable-adjusted hazard ratios (95%CIs) were 1.40 (1.09, 1.79; P-trend = 0.036) for non-spinal fracture and 1.53 (1.13, 2.07; P-trend = 0.010) for major osteoporotic fracture (Q4 compared with Q1 of GS measured in a 300-m buffer). Positive GS-fracture associations were also found for GS within a 500-m buffer.

CONCLUSIONS

We found that those who lived near higher GS levels had a slower increase in lumbar spine BMD and had higher incident fracture risk.

Association of sarcopenia with incident osteoporosis: a prospective study of 168,682 UK biobank participants

BACKGROUND

Sarcopenia often co-occurs with osteoporosis in cross-sectional studies. However, this association has rarely been studied in prospective studies. This study aimed to investigate the association between sarcopenia categories-along with its individual components-and incident osteoporosis in both middle-aged and older men and women from the UK Biobank study.

METHODS

A total of 168,682 participants (48.8% women, aged 37 to 70 years at baseline) were included in this prospective study. Categories of sarcopenia (pre-sarcopenia and sarcopenia), and its individual components, were defined according to the EWGSOP2 criteria (2019). Associations with incident osteoporosis by sex were investigated using Cox-proportional hazard models adjusted for socio-demographic, lifestyle and health-related factors, and morbidity count. Associations between categories of sarcopenia and incident osteoporosis were also investigated by age-groups and subtype of osteoporosis (with and without pathological fractures).

RESULTS

After a median follow-up of 7.4 years, 6296 participants were diagnosed with osteoporosis. When the analyses were adjusted for a range of relevant confounding factors, pre-sarcopenia was associated with 1.3-times higher risk of osteoporosis in men (HR: 1.30 [95% CI: 1.03 to 1.63]) but not in women, and sarcopenia was associated with 1.66-times increased osteoporosis risk in women (HR: 1.66 [95% CI: 1.33 to 2.08]) but not in men compared with people without sarcopenia or pre-sarcopenia. A similar magnitude of associations was found in osteoporosis without pathological fractures but weaker for those with pathological fractures. Within the individual components, low muscle mass (HRwomen : 1.36 [95% CI: 1.22 to 1.51] and HRmen : 3.07 [95% CI: 1.68 to 5.59]), followed by slow gait speed (HRwomen : 1.30 [95% CI: 1.17 to 1.45] and HRmen : 1.70 [95% CI: 1.43 to 2.02]), were associated with a higher risk of incident osteoporosis in both sexes. Low grip strength was associated with a higher risk of incident osteoporosis in men (HR: 1.38 [95% CI: 1.15 to 1.65]), but not in women. No significant interaction between the exposures and incident osteoporosis by age groups were identified.

CONCLUSIONS

Our findings demonstrated that pre-sarcopenic men and sarcopenic women had a higher risk of developing osteoporosis even after adjustment for a large range of potential confounders. Considering that sarcopenia could be prevented, health interventions to improve physical capability may delay or prevent the onset of osteoporosis.

Longitudinal association of built environment pattern with DXA-derived body fat in elderly Hong Kong Chinese: a latent profile analysis

BACKGROUND

One major limitation of prior studies regarding the associations between built environment (BE) and obesity has been the use of anthropometric indices (e.g., body mass index [BMI]) for assessing obesity status, and there has been limited evidence of associations between BE and body fat. This study aimed to explore the longitudinal association between BE and body fat in a cohort of elderly Hong Kong Chinese and examine whether the BE-body fat associations differed by BMI categories.

METHODS

Between 2001 and 2003, 3944 participants aged 65-98 years were recruited and followed for a mean of 6.4 years. BE characteristics were assessed via Geographic Information System. Body fat (%) at whole body and regional areas (trunk, limbs, android, and gynoid) were assessed by dual energy X-ray absorptiometry at baseline and three follow-ups. Latent profile analysis was used to derive BE class, and linear mixed-effects models were used to investigate the associations of BE class with changes in body fat. Stratified analyses by BMI categories were also conducted.

RESULTS

Three BE classes were identified. Participants in Class 2 (characterized by greater open space and proportion of residential land use) had a slower increase in whole body fat (B = -0.403, 95% confidence interval [CI]: -0.780, -0.014) and limbs fat (-0.471, 95% CI: -0.870, -0.071) compared with participants in Class 1 (characterized by high proportion of commercial land use). There were significant interactions of BE class with BMI, and participants in Class 2 had a slower increase in whole body fat and regional fat compared with participants in Class 1 (B ranging from -0.987 [limbs] to -0.523 [gynoid]) among overweight and obese participants only.

CONCLUSIONS

We found that those who resided in the areas characterized by greater open space and proportion of residential land use had a slower body fat increase.

Natural Compounds Attenuate Denervation-Induced Skeletal Muscle Atrophy

The weight of skeletal muscle accounts for approximately 40% of the whole weight in a healthy individual, and the normal metabolism and motor function of the muscle are indispensable for healthy life. In addition, the skeletal muscle of the maxillofacial region plays an important role not only in eating and swallowing, but also in communication, such as facial expressions and conversations. In recent years, skeletal muscle atrophy has received worldwide attention as a serious health problem. However, the mechanism of skeletal muscle atrophy that has been clarified at present is insufficient, and a therapeutic method against skeletal muscle atrophy has not been established. This review provides views on the importance of skeletal muscle in the maxillofacial region and explains the differences between skeletal muscles in the maxillofacial region and other regions. We summarize the findings to change in gene expression in muscle remodeling and emphasize the advantages and disadvantages of denervation-induced skeletal muscle atrophy model. Finally, we discuss the newly discovered beneficial effects of natural compounds on skeletal muscle atrophy.

Osteoporosis in Parkinson's Disease: Relevance of Distal Radius Dual-Energy X-Ray Absorptiometry (DXA) and Sarcopenia

Osteoporotic fractures are common in Parkinson's disease (PD). Standard dual-energy X-ray absorptiometry (DXA) measuring bone mineral density (BMD) at the femoral neck and lumbar spine (central sites) has suboptimal sensitivity in predicting fracture risk in the general population. An association between sarcopenia and osteoporosis in PD has not been studied. We compared BMD and osteoporosis prevalence in PD patients vs controls; determined the osteoporosis detection rates using central alone vs central plus distal radius DXA; and analyzed factors (in particular, sarcopenia) associated with osteoporosis. One hundred and fifty-six subjects (102 patients with PD, 54 spousal/sibling controls) underwent femoral neck-lumbar spine-distal radius DXA. Seventy-three patients and 46 controls were assessed for sarcopenia using whole-body DXA and handgrip strength. Patients underwent clinical and serum biochemical evaluations. PD patients had significantly lower body mass index compared to controls. After adjustment for possible confounders, distal radius BMD and T-scores were significantly lower in PD patients compared to controls, but not at the femoral neck/lumbar spine. With distal radius DXA, an additional 11.0% of patients were diagnosed with osteoporosis (32.0% to 43.0%), vs 3.7% in controls (33.3% to 37.0%) additionally diagnosed; this increase was largely driven by the markedly higher detection rate in female PD patients. Female gender (adjusted odds ratio [OR_adjusted] = 11.3, 95% confidence interval [CI]: 2.6-48.6) and sarcopenia (OR_adjusted = 8.4, 95% CI: 1.1-64.9) were independent predictors for osteoporosis in PD. Distal radius DXA increased osteoporosis detection, especially in female PD patients, suggesting that diagnostic protocols for osteoporosis in PD could be optimized. A close association between osteoporosis and sarcopenia was documented for the first time in PD, which has important implications for clinical management and future research.

[Osteosarcopenia]

Osteoporosis is nowadays understood as an increased risk of fractures, with bone density measurement by dual-energy X‑ray absorptiometry (DXA) being a useful diagnostic criterion and a potent fracture predictor; however, especially in geriatric patients the result is often falsely negative, so that the diagnosis, indications for treatment and treatment selection should be based on an overall clinical evaluation of the individual situation. Sarcopenia is defined as a geriatric syndrome characterized by a generalized loss of skeletal mass and muscle function. Sarcopenia is associated with an increased likelihood of adverse outcomes including falls, fractures, disability and mortality. Since 2018 it is possible in Germany to encode sarcopenia in the International Statistical Classification of Diseases and Related Health Problems, 10th revision, German modification (ICD-10-GM, M62.50). In the case of a high fracture risk and indications for the presence of sarcopenia, the whole body composition should be assessed by DXA within the framework of the measurement of bone mineral density. In the treatment of osteosarcopenia non-pharmacological measures must be initiated in addition to pharmacological measures. It is particularly important to clarify and if necessary to resolve the cause of falls resulting in fractures as well as to regularly reevaluate the treatment goals.

Effects of Medical Treatment of Prostate Cancer on Bone Health

Medical treatment of prostate cancer (PC) is multidisciplinary, resulting in prolonged survival. Androgen-deprivation therapy (ADT) can have negative effects on skeletal metabolism, particularly if combined with glucocorticoids. We discuss the pathophysiology and effects of ADT and glucocorticoids on skeletal endpoints, as well as the awareness and management of bone fragility. Coadministration of glucocorticoids is necessary with abiraterone because this causes a novel acquired form of 17-hydroxylase deficiency and synergistically increases the risk of fracture by affecting bone quality. Bone antiresorptive agents [selective estrogen receptor modulators (SERMS), bisphosphonates, and denosumab] increase bone mineral density (BMD) and in some instances reduce fracture risk in PC patients on ADT. Awareness and management of bone health in PC can be improved by integrating endocrinologists into the multidisciplinary PC team.

Association between handgrip strength and subsequent vertebral-fracture risk following percutaneous vertebral augmentation

INTRODUCTION

The aim of this study was to investigate the association between handgrip strength (HGS) and the risk of subsequent vertebral fracture (SVF) after percutaneous vertebral augmentation (PVA).

MATERIALS AND METHODS

A total of 340 patients aged over 50 years with osteoporotic vertebral fracture were enrolled in this 3-year follow-up investigation. HGS was measured with a hand-held dynamometer before PVA. Female patients and male patients were grouped using the HGS threshold recommended by the Asian Working Group for Sarcopenia (AWGS). Kaplan-Meier analysis was used to evaluate SVF-free survival. The hazard ratios (HRs) of HGS for SVF events were estimated with the Cox proportional hazards model.

RESULTS

During the follow-up period, a total of 93 patients (27.4%) experienced SVF. Kaplan-Meier analysis showed that the HGS of female patients < 18.0 kg and male patients < 28 kg was significantly associated with lower SVF-free survival (female patients: p < 0.001, male patients: p = 0.038; log-rank test). Among women, each 1-kg increase in HGS was associated with a 9% lower risk of SVF (HR 0.91, p = 0.035) after adjustment for potential risk factors. Among men, although the associations between low HGS and increased risk of SVF were significant in the crude model (HR 0.79, p < 0.001), this significance disappeared after adjustment for bone mineral density of the femoral neck.

CONCLUSIONS

Low HGS was significantly associated with lower SVF-free survival among elderly patients who underwent single-level PVA for osteoporotic vertebral fracture.

Long-term changes in lean mass in postmenopausal women and the effects of osteoporosis pharmacotherapy: A 10-year longitudinal study

OBJECTIVES

Although sarcopenia is diagnosed using appendicular lean mass (ALM), only a few long-term studies on changes in both ALM and bone mineral density (BMD) have been reported. The purposes of this study are to evaluate the changes in the parameters of lean mass and bone mass over a 10-year interval and to estimate the effects of osteoporosis pharmacotherapy on muscle.

METHODS

A total of 175 postmenopausal women were evaluated at baseline and after 10 years for BMD, ALM, fat mass, height, and weight. Subjects were further divided into an osteoporosis treatment group (n = 60) and a control group (n = 67) according to whether they had received pharmacotherapy for > 5 years. This was followed by propensity score matching for age, height, weight, and body mass index (BMI), and estimated parameters were compared between groups.

RESULTS

Height, weight, ALM, and fat mass decreased significantly over 10 years (P < 0.05). However, lean mass index (LMI), derived as the ALM divided by the height squared, increased significantly (P < 0.001). BMD increased significantly with osteoporosis treatment (P < 0.05), while no significant differences were observed between the osteoporosis treatment and control groups in the changes to ALM or fat mass.

CONCLUSIONS

ALM was decreased, while LMI was significantly increased. This contradictory result seems to be affected by age-related height loss. Thus, the effect of height loss needs to be considered when sarcopenia is evaluated longitudinally using LMI.

Relationships Between Level and Change in Sarcopenia and Other Body Composition Components and Adverse Health Outcomes: Findings from the Health, Aging, and Body Composition Study

We investigated how baseline values and rates of decline in components of sarcopenia and other body composition parameters relate to adverse clinical outcomes using the Health, Aging, and Body Composition Study. 2689 participants aged 70-79 years were studied. Appendicular lean mass, whole body fat mass, and total hip BMD were ascertained using DXA; muscle strength by grip dynamometry; and muscle function by gait speed. Baseline values and 2-3 year conditional changes (independent of baseline) in each characteristic were examined as predictors of mortality, hospital admission, low trauma fracture, and recurrent falls in the subsequent 10-14 years using Cox regression (generalized estimating equations used for recurrent falls) with adjustment for sex, ethnicity, age, and potential confounders. Lower levels and greater declines in all parameters (excluding hip BMD level) were associated (p < 0.05) with increased rates of mortality; fully-adjusted hazard ratios per SD lower gait speed and grip strength were 1.27 (95% CI 1.19, 1.36) and 1.14 (1.07, 1.21), respectively. Risk factors of hospital admission included lower levels and greater declines in gait speed and grip strength, and greater declines in hip BMD. Lower levels and greater declines in fat mass and hip BMD were associated with low trauma fracture. Lower gait speed, higher fat mass, and both lower levels and greater declines in grip strength were related to recurrent falls. Lower baseline levels and greater declines in musculoskeletal parameters were related to adverse outcomes. Interventions to maximize peak levels in earlier life and reduce rates of age-related decline may reduce the burden of disease in this age group.

Differential impact of osteoporosis, sarcopenia and obesity on physical performance in aging men

PURPOSE

Aging and concurrent constitutional changes as sarcopenia, osteoporosis and obesity are associated with progressive functional decline. Coincidence and mutual interference of this risk factors require further evaluation.

METHODS

Cross-sectional evaluation of musculoskeletal health in a community-dwelling cohort of men aged 65-90 years. Objectives included descriptive analysis of age-related decline in physical performance, prevalence of osteoporosis (FRAX-Score), sarcopenia (EWGSOP criteria) and obesity (BMI > 30 kg/m2) and their coincidence/interference.

RESULTS

Based on 507 participants assessed, aging was associated with progressive functional deterioration, regarding power (chair rise test -1.54% per year), performance (usual gait speed -1.38% per year) and muscle force (grip strength -1.52% per year) while muscle mass declined only marginally (skeletal muscle index -0.29% per year). Prevalence of osteoporosis was 41.8% (n = 212) while only 22.9% (n = 116) of the participants met the criteria for sarcopenia and 23.7% (n = 120) were obese. Osteosarcopenia was found in n = 79 (15.6%), sarcopenic obesity was present in 14 men (2.8%). A combination of all three conditions could be confirmed in n = 8 (1.6%). There was an inverse correlation of BMI with physical performance whereas osteoporosis and sarcopenia did not interfere with functional outcomes.

CONCLUSION

Based on current definitions, there is considerable overlap in the prevalence of osteoporosis and sarcopenia, while obesity appears to be a distinct problem. Functional decline appears to be associated with obesity rather than osteoporosis or sarcopenia. It remains to be determined to what extend obesity itself causes performance deficits or if obesity is merely an indicator of insufficient activity eventually predisposing to functional decline.

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.

Serum Spermidine as a Novel Potential Predictor for Fragility Fractures

CONTEXT

Metabolomics is an emerging tool that provides insights into the dynamics of phenotypic changes. It is a potential method for the discovery of novel serum markers of fracture.

OBJECTIVE

To identify metabolite parameters that can be used as a proxy for osteoporotic fracture risk.

DESIGN

Prospective study based on the Ansung cohort in Korea.

SETTING

The general community.

PARTICIPANTS

A total of 1504 participants with metabolomic analyses.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

Fragility fractures.

RESULTS

We measured 135 baseline metabolite profiles in fasting serum of the participants. The participants had a mean age of 60.2 years and were comprised of 585 (38.9%) men. During a mean 9-year follow-up, 112 osteoporotic fracture events occurred. Of all metabolites measured, only serum spermidine concentrations were positively associated with the risk of fracture (hazard ratio [HR] per 1 μM of spermidine 1.35, 95% confidence interval [CI] = 1.03-1.65, P = 0.020) after adjusting for age, sex, body mass index, diabetes, hypertension, smoking status, previous fracture history, and baseline tibial quantitative ultrasound. Participants with spermidine concentrations >1.57 μM had a 2.2-fold higher risk of fractures (95% CI 1.08-4.51, P = 0.030) compared with those with concentrations ≤1.57 μM after adjustment. In a subgroup analysis, women with baseline spermidine concentrations >1.57 μM also had a 2.4-fold higher risk of fracture than those with concentrations ≤1.57 μM (95% CI 1.02-5.48, P = 0.047).

CONCLUSIONS

Increased baseline spermidine concentrations were associated with a risk of osteoporotic fracture during a mean 9-year follow-up. The biological significance of the metabolites in the musculoskeletal system could be a subject for future studies.