Quantitative analysis of modified functional muscle-bone unit and back muscle density in patients with lumbar vertebral fracture in Chinese elderly men: a case-control study

Role of effective atomic number of paraspinal muscles in the prediction of acute vertebral fracture risk assessment: a cross-sectional case-control study

OBJECTIVES

We aim to investigate the relations among effective atomic number (Zeff), density, and area of paraspinal muscles, volumetric bone mineral density (vBMD), and acute vertebral fractures (VF) by using spectral base images (SBIs) and routine CT images.

METHODS

A total of 223 patients (52 men and 171 women) with acute lumber VF and 776 subjects (286 men and 390 women) without VF of at least 60 years were enrolled and underwent dual-layer detector CT scans. We quantified the cross-sectional area, density (paraSMD), and Zeff of paraspinal muscles by CT images and SBIs and measured vBMD of the lumbar spine by quantitative CT.

RESULTS

Higher vBMD was associated with lower VF risk in both sexes (adjusted OR, 0.33 and 0.43). After adjusting for age and body mass index, the associations of paraSMD with VF were not significant in men, and in women the association was borderline significant (OR, 0.80; 95% CI, 0.64-1.00). However, higher Zeff of paraspinal muscles was associated with lower VF risk in men (adjusted OR, 0.59; 0.36-0.96) but not in women. The associations of all muscle indexes with VF were not significant after further adjusting for vBMD.

CONCLUSIONS

A higher Zeff of paraspinal muscles is associated with lower VF risk in older men but not in older women. The density, area, and Zeff of paraspinal muscles were not vBMD independent risk factors for acute VF.

ADVANCES IN KNOWLEDGE

The effective atomic number of paraspinal muscles might be a potential marker for VF risk prediction.

Relationship between muscle and subcutaneous adipose tissue size and density and proximal femur bone in elderly women with hip fracture

BACKGROUND

Both osteoporosis and sarcopenia are associated with aging, increasing the likelihood of falls in older adults and consequently raising the risk of hip fractures (HF).

AIMS

To explore the relationship between the size and density of muscle and subcutaneous adipose tissue (SAT) and the bone mineral density (BMD) of the proximal femur in elderly women with HF.

METHODS

Quantitative computed tomography (QCT) was conducted on the hips of 661 female participants who experienced low-energy acute HFs to measure both areal BMD (aBMD) and volume BMD (vBMD). Measurements were taken for the cross-sectional area (CSA) and density of the muscle around the hip and adjacent SAT. Multivariable linear regression models were applied to assess the relationship between these parameters.

RESULTS

Most increases in the density of the gluteus medius and minimus muscle (G.Med/MinM) were correlated with higher BMD in the femoral neck fracture (FNF) group with osteoporosis. In the FNF group, gluteus maximus muscle (G.MaxM) density was negatively associated with the BMD parameters of the proximal femur in individuals with osteoporosis, while they were positively associated with nonosteoporosis. In the intertrochanteric fracture (ITF) group without osteoporosis, both FN aBMD and FN vBMD showed significant correlations with G.Med/MinM density.

DISCUSSION

In women with HFs, bone and muscle are closely related.

CONCLUSIONS

In older women with HFs, density but not CSA of the G.Med/MinM were associated with BMD parameters of the proximal femur. Osteoporosis may influence the relationship between G.MaxM density and proximal femur BMD in elderly women with FNF.

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.

The critical impact of traumatic muscle loss on fracture healing: Basic science and clinical aspects

Musculoskeletal trauma, specifically fractures, is a leading cause of patient morbidity and disability worldwide. In approximately 20% of cases with fracture and related traumatic muscle loss, bone healing is impaired leading to fracture nonunion. Over the past few years, several studies have demonstrated that bone and the surrounding muscle tissue interact not only anatomically and mechanically but also through biochemical pathways and mediators. Severe damage to the surrounding musculature at the fracture site causes an insufficiency in muscle-derived osteoprogenitor cells that are crucial for fracture healing. As an endocrine tissue, skeletal muscle produces many myokines that act on different bone cells, such as osteoblasts, osteoclasts, osteocytes, and mesenchymal stem cells. Investigating how muscle influences fracture healing at cellular, molecular, and hormonal levels provides translational therapeutic solutions to this clinical challenge. This review provides an overview about the contributions of surrounding muscle tissue in directing fracture healing. The focus of the review is on describing the interactions between bone and muscle in both healthy and fractured environments. We discuss current progress in identifying the bone-muscle molecular pathways and strategies to harness these pathways as cues for accelerating fracture healing. In addition, we review the existing challenges and research opportunities in the field.

The lumbar spinal endplate lesions grades and association with lumbar disc disorders, and lumbar bone mineral density in a middle-young general Chinese population

BACKGROUND

Lumbar vertebral endplates lesions (LEPLs), one of the etiologies of low back pain (LBP), are one of the most prevalent causes of health-care costs. Despite progressively becoming the focus in recent years, almost all studies have concentrated on symptomatic patients rather than general populations. As a result, our study was designed to determine the prevalence and distribution patterns of LEPLs in a middle-young general population, as well as their associations with lumbar disc herniation (LDH), lumbar disc degeneration (LDD), and lumbar vertebral volumetric bone mineral density (vBMD).

METHODS

Seven hundred fifty-four participants aged 20-60 years were recruited from the subjects enrolled in a 10-year longitudinal study of degeneration of the spine and knee being conducted at the Beijing Jishuitan Hospital and 4 of them were excluded due to the missing of MRIs. In this observational study, a lumbar quantitative computed tomography (QCT) and MRI scan were performed among participants within 48 h. T2-weighted sagittal lumbar MRI images for all included subjects were identified for LEPLs by two independent observers based on morphological and local characteristics. Lumbar vertebral vBMD was measured with QCT. The age, BMI, waistline, hipline, lumbar vBMD, LDD, and LDH were measured to investigate their associations with LEPLs.

RESULTS

The prevalence of LEPLs was higher among the male subjects. 80% of endplates were recognition as no lesions with a substantial disparity between female (75.6%) and male subjects (83.4%) (p < 0.001). The most common lesions were "wavy/irregular" and "notched", and "fracture" is most involved in L3-4 inferior endplate both in two genders. LEPLs were found to be associated with LDH (≥ 2 levels: OR = 6.859, P < 0.001; 1 level: OR = 2.328, P = 0.002 in men. OR = 5.004, P < 0.001; OR = 1.805, P = 0.014 in women) reference for non-LDH, and hipline in men (OR = 1.123, P < 0.001).

CONCLUSIONS

LEPLs are the common findings on lumbar MRIs in general population, particularly in men. The presence of these lesions and advance from slightly to severely could be mainly attributed to LDH and men's higher hipline.

Multisystem physiological perspective of human frailty and its modulation by physical activity

"Frailty" is a term used to refer to a state characterized by enhanced vulnerability to, and impaired recovery from, stressors compared with a nonfrail state, which is increasingly viewed as a loss of resilience. With increasing life expectancy and the associated rise in years spent with physical frailty, there is a need to understand the clinical and physiological features of frailty and the factors driving it. We describe the clinical definitions of age-related frailty and their limitations in allowing us to understand the pathogenesis of this prevalent condition. Given that age-related frailty manifests in the form of functional declines such as poor balance, falls, and immobility, as an alternative we view frailty from a physiological viewpoint and describe what is known of the organ-based components of frailty, including adiposity, the brain, and neuromuscular, skeletal muscle, immune, and cardiovascular systems, as individual systems and as components in multisystem dysregulation. By doing so we aim to highlight current understanding of the physiological phenotype of frailty and reveal key knowledge gaps and potential mechanistic drivers of the trajectory to frailty. We also review the studies in humans that have intervened with exercise to reduce frailty. We conclude that more longitudinal and interventional clinical studies are required in older adults. Such observational studies should interrogate the progression from a nonfrail to a frail state, assessing individual elements of frailty to produce a deep physiological phenotype of the syndrome. The findings will identify mechanistic drivers of frailty and allow targeted interventions to diminish frailty progression.

A Cross-Sectional Study on Gluteal Muscles in Patients with Ankylosing Spondylitis at Different Stages of Hip Involvement

Hip involvement in ankylosing spondylitis (AS) is associated with severe functional impairment, and early diagnosis can improve the disease prognosis. We investigated gluteal muscle cross-sectional area (CSA) and radiodensity at different stages of hip involvement and their associations with AS-related clinical and laboratory parameters. This cross-sectional study included 83 patients with AS and 83 age- and sex-matched controls. Patients with AS were divided into three groups according to the Bath Ankylosing Spondylitis Radiology Hip Index system. The CSA and radiodensity of the gluteus maximus, medius, and minimus muscles were measured using computed tomography images. Muscle parameters were compared, and their relationships with clinical and laboratory parameters were evaluated. For the gluteus maximus, patients with AS had a lower CSA than controls, regardless of the degree of hip involvement. For the gluteus medius and minimus, patients with moderate/advanced hip involvement had significantly lower CSA and radiodensity than those with mild to no hip involvement. The severity of hip involvement was negatively associated with muscle parameters. CSA of the gluteus maximus decreased in early-stage hip involvement without any changes in radiographs, while radiodensity decreased in the later stages. Muscle parameters on computed tomography may be a more sensitive indicator than radiographic findings.

Role of paraspinal muscle degeneration in the occurrence and recurrence of osteoporotic vertebral fracture: A meta-analysis

Purpose

Recently, the effects of paraspinal muscle degeneration on osteoporotic vertebral fractures (OVFs) have attracted the attention of researchers; however, studies are limited, and their results vary. Hence, this study aimed to determine the role of paraspinal muscle degeneration in the occurrence and recurrence of OVF.

Methods

Following the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guideline, the PubMed, Embase, Web of Science, Wanfang Data, China National Knowledge Infrastructure, and ClinicalTrials.gov databases were comprehensively searched for relevant studies. Studies comparing the cross-sectional area (CSA) or fatty infiltration (FI) of the paraspinal muscles (including the psoas (PS), erector spinae plus multifidus (ES+MF), quadratus lumborum) in patients with and without initial OVF, or with and without recurrent OVF were included and analyzed.

Results

Eleven studies were included in the meta-analysis. Seven studies investigated the effects of paraspinal muscles on initial OVF, and the overall results revealed significantly lower CSAES+MF (SMD: -0.575, 95% CI: -0.866 to -0.285) and CSAPS (SMD: -0.750, 95% CI: -1.274 to -0.226), and higher FI (SMD: 0.768, 95% CI: 0.475 to 1.062) in the fracture group. Meanwhile, four studies evaluated the effects of the paraspinal muscles on recurrent OVF, and the pooled results demonstrated significantly higher FI (SMD:0.720, 95% CI: 0.258 to 1.182) in the refracture group, although no significant difference in CSAES+MF (SMD: -0.103, 95% CI: -0.395 to 0.189) was observed between the two groups.

Conclusions

Paraspinal muscle degeneration plays a role in the occurrence and recurrence of OVF. Assessing the paraspinal muscles may be useful for identifying high-risk populations.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier (CRD42021276681).

Cortex or cancellous-which is early for the decrease of bone content for vertebral body in health?

OBJECTIVE

To obtain the cortex and cancellous parameter of the vertebral bone of healthy subjects using QCT. To explore which is earlier or faster for bone loss with age.

MATERIALS AND METHODS

733 physical examiners underwent chest low-dose CT examination were recruited, from April 1, 2021 to October 1, 2021. QCT sequence was used to obtain the bone mineral density of T12-L2 vertebral body without additional radiation. The mass and area of vertebral cortex and cancellous at the central level of L2 vertebral body were measured. The age -related characteristics of vertebral cortex and cancellous between male and female was analyzed and compared.

RESULTS

The vBMD of T12-L2 vertebral body decreased with age. Significant differences were found in volumetric bone mineral density (vBMD) of T12-L2 vertebral body. For female, significant differences were found in bone content involving cortical mass, cancellous mass, cortical area, cancellous area, cortical mass/cancellous mass and cortical area/cancellous area in different age groups, respectively. The cortical mass decreased with age in female. The cancellous mass of female increased and then decreased with peak at 31-40 y. The cortical area of female decreased gradually before 71 y. The cancellous area of female increased and then decreased with peak at 51-60 y. The values of mass ratio and area ratio in female showed a slowly downward trend with age. Significant differences of bone content between non-menopausal and menopausal women were found except the cancellous mass. For male, no significant differences were found in all parameters of bone content.

CONCLUSION

The changes of vertebral BMD, bone content of cortex and cancellous have different characteristics in different age. The change of cortex in female maybe earlier and faster than that of cancellous, especially in menopausal women.

Correlation of muscle mass and bone mineral density in the NHANES US general population, 2017-2018

The appendicular skeletal muscle mass index (ASMI) is commonly used to evaluate human skeletal muscle mass. Muscle, an adjacent tissue of bone, is closely related to bone growth and development. The purpose of this study was to explore the association between the ASMI and lumbar bone mineral density (BMD) to identify potential risk factors for osteoporosis. We analyzed the data collected by the NHANES from 2017 to 2018, and finally included 948 participants aged 40 to 59 years. We evaluated the correlation between the ASMI and lumbar spine BMD using univariate and multiple linear regression models. The ASMI was calculated from height and appendicular skeletal muscle mass obtained by dual energy X-ray absorptiometry. Lumbar spine BMD was obtained by dual energy X-ray absorptiometry and used as an observation in our study. In all the models, ASMI was significantly associated with lumbar spine BMD (model 1: β = 0.013, P < .001; model 2: β = 0.013, P < .001). In the subgroup analysis stratified by sex, this positive correlation was present in both sexes (male: β = 0.023, P < .001, β = 0.022, < 0.001; female: β = 0.030, P < .001, β = 0.031, P < .001). This study showed that the ASMI was positively associated with lumbar BMD, and that this correlation is present in both men and women.

The value of radiomics to predict abnormal bone mass in type 2 diabetes mellitus patients based on CT imaging for paravertebral muscles

OBJECTIVE

To investigate the value of CT imaging features of paravertebral muscles in predicting abnormal bone mass in patients with type 2 diabetes mellitus.

METHODS

The clinical and QCT data of 149 patients with type 2 diabetes mellitus were collected retrospectively. Patients were randomly divided into the training group (n = 90) and the validation group (n = 49). The radiologic model and Nomogram model were established by multivariate Logistic regression analysis. Predictive performance was evaluated using receiver operating characteristic (ROC) curves.

RESULTS

A total of 829 features were extracted from CT images of paravertebral muscles, and 12 optimal predictive features were obtained by the mRMR and Lasso feature selection methods. The radiomics model can better predict bone abnormality in type 2 diabetes mellitus, and the (Area Under Curve) AUC values of the training group and the validation group were 0.94(95% CI, 0.90-0.99) and 0.90(95% CI, 0.82-0.98). The combined Nomogram model, based on radiomics and clinical characteristics (vertebral CT values), showed better predictive efficacy with an AUC values of 0.97(95% CI, 0.94-1.00) in the training group and 0.95(95% CI, 0.90-1.00) in the validation group, compared with the clinical model.

CONCLUSION

The combination of Nomogram model and radiomics-clinical features of paravertebral muscles has a good predictive value for abnormal bone mass in patients with type 2 diabetes mellitus.

Lumbar posterior group muscle degeneration: Influencing factors of adjacent vertebral body re-fracture after percutaneous vertebroplasty

Objective

The purpose of the study was to explore the influencing factors of adjacent vertebral re-fracture after percutaneous vertebroplasty (PVP) for osteoporosis vertebral compression fractures (OVCFs).

Methods

We retrospectively analyzed the clinical data of 55 patients with adjacent vertebral re-fracture after PVP operation for OVCFs in our hospital from January 2016 to June 2019, they were followed up for 1 year and included in the fracture group. According to the same inclusion and exclusion criteria, we collected the clinical data of 55 patients with OVCFs without adjacent vertebral re-fracture after PVP in the same period and included them in the non-fracture group. We performed univariate and multivariate logistic regression analysis on the influencing factors of adjacent vertebral re-fracture in patients with OVCFs after PVP.

Results

There were significant differences in body mass index (BMI), bone mineral density (BMD) T-value, amount of bone cement injected, bone cement leakage, history of glucocorticoid use, cross-sectional area (CSA), cross-sectional area asymmetry (CSAA), fat infiltration rate (FIR), and fat infiltration rate asymmetry (FIRA) of lumbar posterior group muscles [multifidus (MF) and erector spinae (ES)] between the two groups (p < 0.05). There was no significant difference in sex, age, or time from the first fracture to operation, the CAS, CSAA, FIR, and FIRA of psoas major (PS) between the two groups (p > 0.05). Multivariate logistic regression showed that a higher dose of bone cement, greater CSAA and FIR of multifidus, and higher CSAA of erector spinae were independent risk factors for recurrent fractures of adjacent vertebrae after PVP.

Conclusion

There are many risk factors for recurrent vertebral fracture after PVP in patients with OVCFs, and degeneration of paraspinal muscles (especially posterior lumbar muscles) may be one of the risks.

DXA parameters, Trabecular Bone Score (TBS) and Bone Mineral Density (BMD), in fracture risk prediction in endocrine-mediated secondary osteoporosis

Osteoporosis, a disease characterized by low bone mass and alterations of bone microarchitecture, leading to an increased risk for fragility fractures and, eventually, to fracture; is associated with an excess of mortality, a decrease in quality of life, and co-morbidities. Bone mineral density (BMD), measured by dual X-ray absorptiometry (DXA), has been the gold standard for the diagnosis of osteoporosis. Trabecular bone score (TBS), a textural analysis of the lumbar spine DXA images, is an index of bone microarchitecture. TBS has been robustly shown to predict fractures independently of BMD. In this review, while reporting also results on BMD, we mainly focus on the TBS role in the assessment of bone health in endocrine disorders known to be reflected in bone.

Can paraspinal muscle degeneration be a reason for refractures after percutaneous kyphoplasty? A magnetic resonance imaging observation

Background

Vertebral augmentation (VA) techniques are used to treat acute osteoporotic vertebral compression fractures (OVCFs). However, the incidence of recurrent vertebral fractures after VA is controversial. Various factors have been discussed in the literature, but no convincing study on the quality of paraspinal muscles has been reported. The purposes of this study were to evaluate the changes in paraspinal muscles and discuss the relationship between paraspinal muscle degeneration and vertebral refractures after percutaneous kyphoplasty (PKP).

Methods

This retrospective study was conducted in patients who underwent PKP for an initial OVCF between July 2017 and August 2018. Patients were followed up and categorized in the refractured or non-refractured group. A final magnetic resonance imaging (MRI) scan and a preoperative MRI scan were used to determine the measurements. The paraspinal muscles at the mid-height level of the initial fractured vertebral body were measured using regions of interest (ROIs), including the cross-sectional area (CSA) and signal intensity (SI). The changes in the observed data were compared between the groups using rank-sum tests.

Results

Overall, 92 patients were enrolled in the study; 33 of them sustained vertebral refractures during the follow-up and the other 59 patients did not. There were no significant differences in terms of sex, age, preoperative bone mineral density, and body mass index between the groups (all, P > 0.05). The refractured group had a significantly higher decrease in the ROI-CSA and CSA/SI, and a higher increase in ROI-SI, compared with the preoperative data (all, P < 0.05).

Conclusions

The quality of paraspinal muscles significantly decreased in patients with new OVCFs after PKP. This brings a new perspective to the study of postoperative recurrent fractures; patients and physicians need to pay more attention to the efficacy of bed rest and bracing.

The Association of Lumbar Disc Herniation with Lumbar Volumetric Bone Mineral Density in a Cross-Sectional Chinese Study

Little is known about the effect of lumbar intervertebral disc herniation (LDH) on lumbar bone mineral density (BMD), and few previous studies have used quantitative computed tomography (QCT) to assess whether the staging of LDH correlates with lumbar vertebral trabecular volumetric bone mineral density (Trab.vBMD). To explore the relationship between lumbar Trab.vBMD and LDH, seven hundred and fifty-four healthy participants aged 20–60 years were enrolled in the study from an ongoing study on the degeneration of the spine and knee between June 2014 and 2017. QCT was used to measure L2–4 Trab.vBMD and lumbar spine magnetic resonance images (MRI) were performed to assess the incidence of disc herniation. After 9 exclusions, a total of 322 men and 423 women remained. The men and women were divided into younger (age 20–39 years) and older (age 40–60 years) groups and further into those without LDH, with a single LDH segment, and with ≥2 segments. Covariance analysis was used to adjust for the effects of age, BMI, waistline, and hipline on the relationship between Trab.vBMD and LDH. Forty-one younger men (25.0%) and 59 older men (37.3%) had at least one LDH segment. Amongst the women, the numbers were 46 (22.5%) and 80 (36.4%), respectively. Although there were differences in the characteristics data between men and women, the difference in Trab.vBMD between those without LDH and those with single and ≥2 segments was not statistically significant (p > 0.05). These results remained not statistically significant after further adjusting for covariates (p > 0.05). No associations between lumbar disc herniation and vertebral trabecular volumetric bone mineral density were observed in either men or women.

The effect of ageing on skeletal muscle as assessed by quantitative MR imaging: an association with frailty and muscle strength

Background

Skeletal muscles undergo changes with ageing which can cause sarcopenia that can result in frailty. Quantitative MRI may detect the muscle-deficit component of frailty which could help improve the understanding of ageing muscles.

Aims

To investigate whether quantitative MRI measures of T2, fat fraction (FF), diffusion tensor imaging and muscle volume can detect differences within the muscles between three age groups, and to assess how these measures compare with frailty index, gait speed and muscle power.

Methods

18 ‘young’ (18–30 years), 18 ‘middle-aged’ (31–68 years) and 18 ‘older’ (> 69 years) healthy participants were recruited. Participants had an MRI of their dominant thigh. Knee extension and flexion power and handgrip strength were measured. Frailty (English Longitudinal Study of Ageing frailty index) and gait speed were measured in the older participants.

Results

Young participants had a lower muscle MRI T2, FF and mean diffusivity than middle-aged and older participants; middle-aged participants had lower values than older participants. Young participants had greater muscle flexion and extension power, muscle volume and stronger hand grip than middle-aged and older participants; middle-aged participants had greater values than the older participants. Quantitative MRI measurements correlated with frailty index, gait speed, grip strength and muscle power.

Discussion

Quantitative MRI and strength measurements can detect muscle differences due to ageing. Older participants had raised T2, FF and mean diffusivity and lower muscle volume, grip strength and muscle power.

Conclusions

Quantitative MRI measurements correlate with frailty and muscle function and could be used for identifying differences across age groups within muscle.

Age-related degeneration of lumbar muscle morphology in healthy younger versus older men

AIM

The aim of this study was to evaluate age-related changes in lumbar paravertebral muscle (LPM) morphology in healthy younger and older adult men.

METHODS

T2-weighted axial MRI of the lumbar spine were obtained for 12 healthy older (67.3 ± 6.0 years) and younger (24.7 ± 3.1 years) men. Normalised muscle volume (NMV) and muscle fat infiltrate (MFI) were determined bilaterally for the psoas (PS), quadratus lumborum (QL), erector spinae (ES) and multifidus (MF). MANOVA was used to compare NMV and MFI between age groups. Follow-up ANOVA compared NMV and MFI for each muscle between age groups, with physical activity (PA) as a covariate. Stepwise regression was used to explore the association between muscle morphology.

RESULTS

NMV of the ES and QL were significantly lower in the older group (OG) (p = 0.040 and p < 0.001, respectively). MFI across all muscles was significantly greater in the OG (p < 0.001). PA did not moderate the relationship between aging and muscle degeneration. Non-dominant handgrip strength was associated with NMV (p = 0.003).

CONCLUSIONS

Age-related atrophy is muscle specific in the lumbar spine; changes in lumbar musculature is independent of PA, handgrip strength may reflect morphological changes in the postural muscles with age. This study supports establishing effective targeted exercise interventions in the lumbar musculature.

Differences between muscle from osteoporotic and osteoarthritic subjects: in vitro study by diffusion-tensor MRI and histological findings

BACKGROUND

Osteoarthritis and osteoporosis are strongly coupled with alterations of muscles quality and fats metabolism. However, there are no studies for investigating possible differences between osteoporotic and osteoarthritic muscles. Understanding muscle-bone and muscle-cartilage interactions would be of high clinical value.

AIM

Investigate potential microstructural and physiological differences between osteoporotic and osteoarthritic muscles by diffusion Nuclear Magnetic Resonance (NMR) imaging (diffusion MRI) and histological findings.

METHODS

Vastus-lateralis muscles excised from osteoporotic (n = 26, T Score <  - 2.5, Kellgren-Lawrence ≤ 2) and osteoarthritic (n = 26, T Score >  - 2.5, Kellgren--Lawrence 3 and 4) age-matched women were investigated by NMR relaxometry, diffusion-tensor imaging (DTI) at 9.4 T, and histological techniques. Intramyocellular (IMCL) and extramyocellular (EMCL) lipid were quantified. The percentage and mean diameters of fibers I and II were evaluated. Relationship between mean diffusivity (MD), fractional anisotropy (FA), the DTI eigenvalues (λ₁, λ₂, λ₃), histological findings in muscles and clinical data (Kellgren-Lawrence and T score, age, menopausal age, body mass index) were studied. Pairwise comparisons between groups were made using one-way analysis of variance and correlation between variables was assessed with linear correlation analysis (Pearson's r coefficient).

RESULTS

Osteoporotic muscles showed higher MD, λ_1, λ₂, λ₃ compared to osteoarthritis ones. This is explainable with a significant higher density of IMCL droplets found inside the osteoarthritic muscles and a large amount of fibrotic tissue and IMCL infiltration between fibers, i.e. in endomysium and perimysium that lead to a more hindered diffusion. Furthermore, histological analysis suggests mitochondrial degeneration as the origin of the greatest amount of IMCL droplets in osteoarthritic muscles.

CONCLUSION

This work highlights differences between muscles of osteoporotic and osteoarthritic subjects that can be quantified by NMR DTI investigations.

Osteosarcopenia among postmenopausal women and handgrip strength as a practical method for predicting the risk

BACKGROUND

Osteosarcopenia is a recently described geriatric syndrome. Studies concerning its role on physical function are relatively few.

AIM

To evaluate the prevalence of osteosarcopenia and to analyze its relationship with physical function among postmenopausal women.

METHODS

Demographic and clinical data, fracture risk, and osteosarcopenia risk factors of 140 postmenopausal women were evaluated between April 2018 and September 2018. Body composition and bone mineral density were measured by dual-energy X-ray absorbtiometry. Handgrip strength and physical performance test results were recorded. Sarcopenia was diagnosed according to the European Working Group on Sarcopenia in Older People, whereas osteopenia/osteoporosis was diagnosed according to the World Health Organisation criteria.

RESULTS

The mean age of the patients was 64.1 ± 8.9 years. Among the patients, 64.3% (n = 90) were found to be osteosarcopenic. Insufficient protein and calcium intake and low physical activity level were found to be the most frequent risk factors. When further analysis was done according to the osteosarcopenia, sarcopenia-only, and osteoporosis-only groups, osteosarcopenia group revealed the lowest body mass index, skeletal mass index, handgrip strength values, and physical performance test results. The handgrip strength was found to be a determinant of osteosarcopenia and each 1-unit decrease in handgrip strength increased the risk of osteosarcopenia by 1.162 times (95% CI 1.086-1.25).

CONCLUSIONS

The prevalence of osteosarcopenia is high among postmenopausal women. It is recommended to be aware of osteosarcopenia while managing osteoporotic patients, to use handgrip strength as a simple screening method, and to consider sarcopenia treatment as an important component of osteoporosis prevention and treatment.

Changes to Body Composition in Women With Long-Standing Established Rheumatoid Arthritis: Differences by Level of Disease Activity

INTRODUCTION

Few studies on rheumatoid arthritis have investigated disease activity and body composition by dual-energy X-ray absorptiometry including evaluation of visceral adipose tissue. Thus, we sought to verify the association between body composition by dual-energy X-ray absorptiometry, including visceral adipose tissue, and inflammatory activity in long-standing established rheumatoid arthritis.

METHODS

Seventy-eight postmenopausal women with rheumatoid arthritis (American College of Rheumatology 2010) were studied. Disease activity was assessed by composite indexes (DAS28, CDAI, SDAI) and C-reactive protein. Potential association between body composition and disease activity was analysed by Pearson correlation and Tukey´s test (p < 0.05).

RESULTS

There was significant negative correlation between C-reactive protein and appendicular lean mass index (r = -0.234, p = 0.039). After adjusting for confounding variables, women with C-reactive protein >10 mg/L had a lower appendicular lean mass index than those with C-reactive protein 5-10 mg/L and <5 mg/L (6.3 ± 0.8 kg/m² vs 7.2 ± 1.2 kg/m² vs 6.8 ± 1.0 kg/m², respectively; p = 0.013). Women with moderate inflammation (C-reactive protein 5-10 mg/L) had more fat than those with C-reactive protein >10 mg/L and C-reactive protein <5 mg/L (12.4 ± 3.5 kg/m² vs 9.9 ± 3.6 kg/m² vs 10.5 ± 2.8 kg/m², respectively; p = 0.040), as well as more visceral adipose tissue than women with higher and lower C-reactive protein (812.5 ± 266.4 cm³ vs 604.3 ± 236.3cm³ vs 658.9 ± 255.6 cm³; p = 0.009).

CONCLUSIONS

High inflammatory activity that persists after a long disease duration was associated with both lower muscle and fat mass (including visceral adipose tissue), which is suggestive of more exuberant rheumatoid cachexia. Conversely, moderate activity was associated with greater visceral adipose tissue, which is associated with increased cardiovascular risk. These results point to the existence of different body composition profiles according to inflammatory status and the importance of individualized approaches to muscle mass and adiposity according to disease activity level in long-standing rheumatoid arthritis.

Muscle thickness contribution to sit-to-stand ability in institutionalized older adults

BACKGROUND

Ultrasound is a low-cost, safe and accessible tool to use on muscle mass assessment. The relations between muscle thickness and lower limb function have not been investigated in institutionalized elderly people.

AIM

The purpose of the present study was to investigate the associations among sit-to-stand capacity, ultrasound-measured rectus femoris muscle thickness, hand grip strength and anthropometrics in a population of institutionalized older adults.

METHODS

Twelve older adults (nine women and three men, mean age ± SD 86 ± 7 years, body mass index 24 ± 3 kg/m²) participated in this cross-sectional study. Sit-to-stand capacity using five-repetition sit-to-stand test, rectus femoris muscle thickness using B-mode ultrasonography, handgrip and anthropometric were measured. The relationships of the variables were analyzed using Pearson correlation coefficient and multiple linear regression analysis.

RESULTS

Significant bivariate correlations were found between rectus femoris muscle thickness and sit-to-stand test (p < 0.05). Multiple linear regression analysis showed associations between rectus femoris muscle thickness and sit-to-stand test, after adjusting by body mass index and age (p < 0.0001).

DISCUSSION

Rectus femoris thickness in contraction adjusted by body mass index and age was predictors of physical performance. The independent variables shared 78.6% of variance in the sit-to-stand test.

CONCLUSIONS

Rectus femoris muscle thickness measured with ultrasonography, body mass index and age could explain functionality in institutionalized older adults measured by five-repetition sit-to-stand test.

Lumbar facet joint subchondral bone density in low back pain and asymptomatic subjects

OBJECTIVE

To report in vivo measurements of lumbar facet joint subchondral bone mineral density used in the description of facet joint loading patterns and to interrogate if low back pain is associated with changes in subchondral bone mineral density.

MATERIALS AND METHODS

In vivo measurements of lumbar facet joint subchondral bone mineral density (L1/2 to L5/S1) in Hounsfield units were performed on 89 volunteers (56 controls and 33 with low back pain) by computed tomography osteoabsorptiometry at subchondral regions between 1.5 mm and 2.5 mm below the joint surface. The facet surface was divided into five topographic zones: cranial, lateral, caudal, medial, and central.

RESULTS

We analyzed 1780 facet joint surfaces. Facets were denser (p < 0.0001) both in superior facets and in low back pain subjects (p < 0.0001). For the entire cohort, the facet center zone subchondral bone mineral density was higher (p < 0.0001) than that of the peripheral zones. The analyses indicate that subchondral bone mineral density is highest in patients with low back pain, the superior facets, and the center zone of the facets.

CONCLUSIONS

Subchondral bone mineral density is thought to reflect cumulative, long-term distribution of stress acting on a joint. This work shows that higher subchondral bone mineral density values in the center zone indicate predominant stress transmission through the center of the facet joints. Finally, the greater subchondral bone mineral density in patients with low back pain may reflect both increased load bearing by the facets secondary to disc degeneration and misdistribution of loading within the joint.

Associations of Muscle Size and Density With Proximal Femur Bone in a Community Dwelling Older Population

Background and Purpose: Muscle weakness and bone fragility are both associated with hip fracture. In general, muscle contractions create forces to the bone, and bone strength adapts to mechanical loading through changes in bone architecture and mass. However, the relationship between impairment of muscle and bone function remain unclear. In particular, the associations of muscle with properties of proximal femur cortical and trabecular bone are still not well understood. The aim of this study was to explore the associations of hip/thigh muscle density (CT attenuation value in Hounsfield units) and size with cortical and trabecular bone mineral density (BMD) of the proximal femur. Materials and Methods: Three-dimensional quantitative computed tomography (QCT) imaging of the lumber, hip and mid-thigh was performed in a total of 301 participants (mean age 68.4 ± 6.1 years, 194 women and 107 men) to derive areal BMD (aBMD) and volumetric BMD (vBMD). Handgrip strength (HGS) and the Timed Up and Go (TUG) test were also performed. From the CT images, cross-sectional area (CSA), and density were determined for the gluteus maximus muscle (G.MaxM), trunk muscle at the vertebrae L2 level, and mid-thigh muscle. Multivariate generalized linear models were applied to assess associations. Results: Total hip (TH) aBMD was associated significantly with G.MaxM CSA (men: P = 0.042; women: P < 0.001) and density (men: P = 0.012; women: P = 0.043). In women, 0.035 cm² of mid-thigh CSA (95% CI, 0.014-0.057; P = 0.002) increased per SD increase in TH aBMD, but this significance was not observed in men (P = 0.095). Trunk muscle density and CSA were not associated with proximal femur BMD. The associations of hip/thigh muscle parameters with femoral neck BMD were weaker than those with trochanter and intertrochanter BMD. Furthermore, compared to muscle density, muscle CSA showed better associations with vBMD. G.MaxM CSA was associated with trochanter (TR) Cort. vBMD in men (β, 19.898; 95% CI, 0.924-38.871; P = 0.040) and in women (β, 15.426; 95% CI, 0.893-29.958; P = 0.038). Handgrip strength was only associated with TR aBMD (β, 0.038; 95% CI, 0.006-0.070; P = 0.019) and intertrochanter aBMD (β, 0.049; 95% CI, 0.009-0.090; P = 0.016) in men. Conclusions: We observed positive associations of the gluteus and thigh muscle size with proximal femur volumetric BMD. Specifically, the gluteus maximus muscle CSA was associated with trochanter cortical vBMD in both men and women.

Evaluation of baseline fracture risk in younger postmenopausal women with breast cancer using different risk assessment methods

OBJECTIVE

Controversy exists about the impact of bone mineral density (BMD) and fracture risk in newly diagnosed patients with breast cancer (BC). It is presumed that there are differences in BMD between women with BC and healthy controls. BMD is therefore considered as a potential marker to predict BC risk. This study was conducted to investigate the association of BMD, trabecular bone score (TBS) and fracture risk in younger postmenopausal women with hormone responsive BC.

METHODS

Overall, 343 women were examined. Women with BC were matched to a control group of the general population. Forty-nine women and fifty-nine controls were included in the final analysis. All subjects underwent dual energy x-ray absorptiometry (DXA) of the lumbar spine, femoral neck, and the total hip to evaluate bone mineral density. The 10-year fracture risk for a major osteoporotic fracture was assessed using the FRAX-score and the TBS-adjusted FRAX-Score, respectively.

RESULTS

Lumbar and femoral neck BMD were similar in BC patients and controls. No difference was found for TBS of the spine (1.38 ± 0.1 vs.1.36 ± 0.09) in the BC and the control group, respectively (p = 0.19). The 10- year probability for a major osteoporotic fracture (MoF) or femoral neck (FN) fracture was 6.1 (± 2.6%) and 0.9 (± 1.2%) in the BC group vs. 6.7 (± 3.5%) (p = 0.33) and 0.9 (± 1.1%) (p = 0.73) in the control group.

CONCLUSION

Postmenopausal women younger than 60 years with breast cancer do not show any differences in baseline BMD, TBS, or TBS adjusted FRAX in comparison to controls.

Reproducibility of DXA-based bone strain index and the influence of body mass: an in vivo study

OBJECTIVES

Bone strain index (BSI) is a dual-energy X-ray absorptiometry (DXA)-derived index of bone strength obtained from lumbar densitometric scan. We estimated the reproducibility of BSI in healthy women with different body mass index.

METHODS

We enrolled postmenopausal women (mean age ± SD: 66 ± 10 years) divided into three groups (A, B and C) according to body mass index (BMI: < 25; 25-29.9; ≥ 30 kg/m²) and two groups (D and E) according to waist circumference (WC: ≤ 88; > 88 cm), each of 30 subjects. They underwent two DXA examinations with in-between repositioning, according to the International Society for Clinical Densitometry guidelines for precision estimation. Bone mineral density (BMD) and BSI were expressed as g/cm² and absolute value, respectively. The coefficient of variation (CoV) was calculated as the ratio between root-mean-square standard deviation and mean; least significant change percentage (LSC%) as 2.77 × CoV; reproducibility as the complement to 100% LSC.

RESULTS

BSI increased proportionally to BMI and WC and significantly in group C compared to B and A (p = 0.032 and 0.006, respectively). BSI was significantly higher in E compared to D (p = 0.017), whereas no differences were observed in BMD. Although BSI reproducibility was slightly lower in group C (89%), the differences were not significant between all groups. BMD reproducibility did not significantly differ between all groups.

CONCLUSIONS

BSI reproducibility was significantly lower than that of BMD and decreased proportionally to BMI and WC increase. This reduction of BSI reproducibility was more pronounced in patients with BMI ≥ 30 and WC > 88, as expected, being BSI a parameter sensible to weight.

Underreporting characteristics of osteoporotic vertebral fracture in back pain clinic patients of a tertiary hospital in China

Aim

Osteoporotic vertebral compressive fractures (VCFs) ​are known to be commonly missed in X-rays indicated for pulmonary or heart diseases. In this study, we investigated the underreporting status of VCF in back pain clinic patients when the spine was the focus of interest.

Materials and methods

This is a retrospective analysis of 105 female cases (mean: 72 years, range: 55–93 years) from a tertiary hospital in China (facility A, FA). The patients with back and/or leg pain were referred for a spine X-ray. The images were retrieved and transferred to a central reading facility (facility B, FB), where images were double-read by two readers experienced in evaluating osteoporotic vertebral compressive deformity (VCD)/VCF. A qualitative VCD with <20%, 20–25%, 25–40%, and >40% vertebral body height loss was recorded as minimal, mild, moderate, and severe grades, respectively. A ​VCD coexisted with endplate/cortex fracture (ECF) was VCF. FB readings were considered as the reference.

Results

There were 34 true negative cases where FA and FB had a consensus. In 7 cases with minimal VCD, 3 cases with ECF, and 7 cases with minimal or mild VCFs, the FA readings were false negative. No standalone singular moderate or severe VCD/VCF in a patient was missed in FA's reports. In 25 FA reading positive cases with multiple VCFs, one VCF was missed in 8 cases, more than one VCF was missed in 15 cases, and one additional ECF was missed in 2 cases. In 14 cases, FA and FB had VCF number agreement, with the term ‘vertebral fracture’ was used appropriately in FA reports. In 15 cases, FA and FB had agreement in VCF number; however, the appropriate term ‘vertebral fracture’ was not used in FA reports; instead the terms of ‘compressive change’ or ‘wedging change’ were used. In most VCFs, severity grading was not given in FA. In 13 VCFs where grading was reported, all were marked as ‘mild’, including seven mild VCFs, five moderate VCFs, and even one severe VCF.

Conclusion

Among the patients with VCD/VCF, the false negative rate among was 23.9% (17/71), but the missed cases were all minimal or mild grades. One or more VCFs were missed in 32.4% (23/71) of the cases with multiple VCFs. Appropriate severity grading was not reported for most cases.

The translational potential of this article

The underreporting rate of osteoporotic vertebral compressive fracture in back pain clinic patients in a typical tertiary hospital setting in China compared favorably with literature reports. However, there is a general lack of awareness of vertebral endplate/cortex fracture sign and vertebral fracture severity grading, while minimal and mild VCD with endplate/cortex fracture may have clinical significance. Moreover, after one VCF is spotted in a patient, it is highly advisable to carefully check the whole spine so that multiple VCFs will not be missed.