Exercise effects on bone mineral density in older adults: a meta-analysis of randomized controlled trials

Impact of 24-week concurrent training on bone parameters and plasma levels of osteoglycin and sclerostin in young, sedentary adults: secondary analyses from the ACTIBATE randomized controlled trial

OBJECTIVE

To examine the effects of 24-week moderate (MOD-EX) and vigorous-intensity concurrent training (VIG-EX) on bone parameters and plasma levels of osteoglycin and sclerostin and their interplay with body composition and cardiometabolic risk factors in young, sedentary men and women.

DESIGN

Secondary study from the ACTIBATE randomized controlled trial (ClinicalTrials.gov ID: NCT02365129).

METHODS

This study was performed at the Sport and Health University Research Institute and the Virgen de las Nieves University Hospital of the University of Granada. Bone parameters were measured by dual-energy X-ray absorptiometry, and osteoglycin and sclerostin levels, by enzyme-linked immunosorbent assay.

RESULTS

145 young sedentary adults were assigned to a control (CON, n = 54), a MOD-EX (n = 48), or a VIG-EX (n = 43). 106 participants were included in the per-protocol analyses (CON, n = 42; MOD-EX, n = 33; and VIG-EX, n = 31). After 24 weeks of concurrent training, we observed no differences in changes in bone parameters (all P time × group ≥ .300), osteoglycin (P time × group = .250), and sclerostin levels (P time × group = .489). Moreover, we found no correlations between osteoglycin and sclerostin levels with body composition (all P ≥ .639) and cardiometabolic risk factors (all P ≥ .119).

CONCLUSION

24 weeks of concurrent training did not alter bone parameters, and plasma levels of osteoglycin and sclerostin in young, sedentary adults. Moreover, osteoglycin and sclerostin are not related with bone parameters and cardiometabolic risk factors in this population. These findings suggest that longer concurrent training interventions may be needed to enhance bone parameters in young, sedentary adults.

Concurrent effects of high-intensity interval training and vitamin D supplementation on bone metabolism among women diagnosed with osteoporosis: a randomized controlled trial

BACKGROUND

Osteoporosis is often responsible for bone fragility and increased fracture risk due to the micro-architectural deterioration of bone tissue. In addition to nutritional supplements, exercise is considered an adjunct factor in safeguarding bone health. This study aimed to investigate the effects of 16-week high-intensity interval training (HIIT) and vitamin D supplementation on bone mineral density (BMD) in women with osteoporosis.

TRIAL DESIGN

This study used a four-arm pretest-posttest experimental randomized controlled design.

METHODS

One hundred twenty sedentary women aged (30-50 years), diagnosed with osteoporosis were recruited in this study. Patients were randomly classified into four groups with 30 patients in each group: control group (normal daily activities), exercise group (HIIT-exercise for 16 weeks), Vitamin D group (vitamin D 800IU/ day for 16 weeks), and concurrent group (HIIT exercise plus vitamin D for 16 weeks). Anthropometric measurements, BMD, and serum levels of vitamin 25-(OH) D, Osteocalcin, s-BAP, and calcium were estimated in all participants before and after exercise training.

RESULTS

Serum samples revealed that bone resorption markers, osteocalcin, total calcium, s-BAP, and vitamin 25(OH) D significantly improved in all groups; there was greater improvement in the HIIT training-vitamin D group than in the HIIT training, vitamin D, and control groups. Furthermore, the HIIT training-vitamin D group showed improvements in hip (right and left) and lumbar spine BMD than the HIIT training, Vitamin D, and Control groups. BMD improvements correlated positively with serum osteocalcin levels and total calcium and negatively with BMI and s-BAP.

CONCLUSIONS

Sixteen weeks of HIIT and vitamin D consumption showed greater benefits for BMD levels in women with osteoporosis than either vitamin D consumption or HIIT training alone. Therefore, HIIT plus vitamin D consumption may be a strategic option to prevent BMD reduction with aging or to slow demineralization.

TRIAL REGISTRATION

The study protocol was retrospectively registered at 'ClinicalTrials.gov PRS' under the trial identifier NCT06624657, dated 1/10/2024.

Effect of different types of exercise on bone mineral density in postmenopausal women: a systematic review and network meta-analysis

Postmenopausal women (PMW) experience the decline of ovarian function; estrogen reduction will accelerate bone mass loss. Exercise is an effective means of mitigating bone mineral density (BMD) loss in PMW, but the relative effectiveness of different exercise types remains under investigation. Our study encompassed a thorough assessment and network meta-analysis, following the principles specified in the Preferred Reporting Items for Systematic Reviews and Network Meta-analysis (PRISMA) statement. Data sources and searches Literature search databases include PubMed, Embase, Cochrane, Google Scholar, Web of Science (WOS), and Scopus. The data search combined keywords like bone mineral density (BMD), postmenopausal women, and various exercise types. Data synthesis and analysis Perform a network meta-analysis by integrating both direct and indirect comparisons using the R environment. This network meta-analysis aimed to evaluate and compare various exercise types with bone mineral density in PMW to identify the most effective types. The literature comprised a collective of 49 papers, encompassing 3360 people across eight interventions. The Network Meta-analysis ranked the effects of exercise interventions on lumbar spine BMD in descending order, based on the p-scores assigned to them in the forest plot. The exercise modalities that showed significant efficacy were AE + RT(Aerobic Mixed Resistance Exercise, MD = 32.35, 95% CrI [8.08;56.62], p = 0.87), AE(Aerobic Exercise, MD = 22.33, 95% CrI [6.67;37.99], p = 0.74), and RT(Resistance Training, MD = 16.98, 95% CrI [8.98;24.99], p = 0.60). Similarly, the femoral neck sites were ranked in descending order based on their p-scores in the forest plot, and the exercise patterns with significant effects on lumbar spine bone mineral density were AE + RT(MD = 140, 95% CrI [40.89;239.11], p = 0.99), WBV(Whole Body Vibration, MD = 26.07, 95% CrI [2.97;49.16], p = 0.80), and RT(MD = 16.98, 95% CrI [8.98;24.99], p = 0.72). Exercise intervention significantly and effectively alleviated BMD in postmenopausal women, with AE + RT having the best effect.

Mitochondrial oxidative stress or decreased autophagy in osteoblast lineage cells is not sufficient to mimic the deleterious effects of aging on bone mechanoresponsiveness

Exercise-induced mechanical load stimulates bone cells, including osteocytes, to promote bone formation. The bone response to loading is less effective with aging, but the cellular and molecular mechanisms responsible for the impaired mechanoresponsiveness remain unclear. Excessive mitochondrial reactive oxygen species (mtROS) and deficient autophagy are common aging mechanisms implicated in decreased bone formation in old mice. Here, we confirmed that the osteogenic effects of tibia compressive loading are lower in old versus young female mice. We also examined whether an increase in mtROS or decreased autophagy in osteoblast-lineage cells of adult female mice could mimic the deleterious effects of aging. To this end, we loaded mice lacking the antioxidant enzyme superoxide dismutase 2 (Sod2) or autophagy-related 7 (Atg7) in cells targeted by Osterix1 (Osx1)-Cre. Osteocytes in Atg7ΔOsx1 exhibited altered morphology and decreased osteocyte dendrite projections. Two weeks of loading increased cortical bone mass and bone formation rate at both periosteal and endosteal surfaces of Osx1-Cre control mice. Nonetheless, in both Atg7ΔOsx1 and Sod2ΔOsx1 mice the response to loading was identical to that observed in control mice, indicating that compromised Atg7-dependent autophagy or excessive mtROS are not sufficient to impair the bone response to tibial compressive loading. Thus, alternative mechanisms of aging might be responsible for the decreased response of the aged skeleton to mechanical stimuli. These findings also suggest that an intact osteocyte dendrite network is not required for the osteogenic response in this model of bone loading.

Activation of connexin hemichannels enhances mechanosensitivity and anabolism in disused and aged bone

Mechanical loading, essential for bone health, promotes bone formation and remodeling. However, the positive response diminishes in cases of disuse and aging, leading to bone loss and an increased fracture risk. This study demonstrates that activating hemichannels (HCs) using a connexin 43 (Cx43) antibody, Cx43(M2), in bone osteocytes revitalizes aging and disused bones. Using a hindlimb suspension (HLS) disuse model and a tibial mechanical loading model, we found that Cx43(M2) inhibited bone loss and osteocyte apoptosis induced by unloading in 16-week-old adult mice. Additionally, it enhanced bone mass in response to tibial loading in 22-month-old aged mice. The HC opening released bone anabolic factor prostaglandin E2 (PGE2) and suppressed catabolic factor sclerostin (SOST). This suppressed the increase of cortical bone formation and reduction of bone resorption during unloading and promoted trabecular and cortical bone formation during loading. Cx43(M2)-induced HC opening, coupled with PGE2 release, effectively rescued unloading-induced bone loss and restored the diminished anabolic response of aged bones to mechanical loading. Activating HCs with the Cx43 antibody holds promise as a de novo therapeutic approach, as it can overcome the limitations of existing treatment regimens for treating bone loss and osteoporosis associated with aging and disuse.

The effects of endurance trainability phenotype, sex, and interval running training on bone collagen synthesis in adult rats

Bone is influenced by many factors such as genetics and mechanical loading, but the short-term physiological effects of these factors on bone (re)modelling are not well characterised. This study investigated the effects of endurance trainability phenotype, sex, and interval running training (7-week intervention) on bone collagen formation in rats using a deuterium oxide stable isotope tracer method. Bone samples of the femur diaphysis, proximal tibia, mid-shaft tibia, and distal tibia were collected after necropsy from forty-six 9 ± 3-month male and female rats selectively bred for yielding low (LRT) or high (HRT) responses to endurance training. Bone collagen proteins were isolated and hydrolysed, and fractional synthetic rates (FSRs) were determined by the incorporation of deuterium into protein-bound alanine via GC-pyrolysis-IRMS. There was a significant large main effect of phenotype at the femur site (p < 0.001; η2g = 0.473) with HRT rats showing greater bone collagen FSRs than LRT rats. There was a significant large main effect of phenotype (p = 0.008; η2g = 0.178) and a significant large main effect of sex (p = 0.005; η2g = 0.196) at the proximal site of the tibia with HRT rats showing greater bone collagen FSRs than LRT rats, and male rats showing greater bone collagen FSRs compared to female rats. There was a significant large main effect of training at the mid-shaft site of the tibia (p = 0.012; η2g = 0.159), with rats that underwent interval running training having greater bone collagen FSRs than control rats. Similarly, there was a significant large main effect of training at the distal site of the tibia (p = 0.050; η2g = 0.156), with rats in the interval running training group having greater bone collagen FSRs compared to rats in the control group. Collectively, this evidence highlights that bone responses to physiological effects are site-specific, indicating that interval running training has positive effects on bone collagen synthesis at the tibial mid-shaft and distal sites, whilst genetic factors affect bone collagen synthesis at the femur diaphysis (phenotype) and proximal tibia (phenotype and sex) in rats.

Effect of different running protocols on bone morphology and microarchitecture of the forelimbs in a male Wistar rat model

BACKGROUND

It is accepted that the metabolic response of bone tissue depends on the intensity of the mechanical loads, but also on the type and frequency of stress applied to it. Physical exercise such as running involves stresses which, under certain conditions, have been shown to have the best osteogenic effects. However, at high intensity, it can be deleterious for bone tissue. Consequently, there is no clear consensus as to which running modality would have the best osteogenic effects.

AIM

Our objective was to compare the effects of three running modalities on morphological and micro-architectural parameters on forelimb bones.

METHODS

Forty male Wistar rats were randomly divided into four groups: high intensity interval training (HIIT), continuous running, combined running ((alternating HIIT and continuous modalities) and sedentary (control). The morphometry, trabecular microarchitecture and cortical porosity of the ulna, radius and humerus were analyzed using micro-tomography.

RESULTS

All three running modalities resulted in bone adaptation, with an increase in the diaphyseal diameter of all three bones. The combined running protocol had positive effects on the trabecular thickness in the distal ulna. The HIIT protocol resulted in an increase in both medio-lateral diameter and cortical bone area over total area (Ct.Ar/Tt.Ar) at the ulnar shaft compared with sedentary condition. Moreover, the HIIT protocol decreased the mean surface area of the medulla (Ma.Ar) according to sedentary condition at the ulnar shaft.

CONCLUSION

This study has shown that HIIT resulted in a decrease in trabecular bone fraction in favor of cortical bone area at the ulna.

A proteomics approach to study mouse long bones: examining baseline differences and mechanical loading-induced bone formation in young-adult and old mice

With aging, bone mass declines and the anabolic effects of skeletal loading diminish. While much research has focused on gene transcription, how bone ages and loses its mechanoresponsiveness at the protein level remains unclear. We developed a novel proteomics approach and performed a paired mass spectrometry and RNA-seq analysis on tibias from young-adult (5-month) and old (22-month) mice. We report the first correlation estimate between the bone proteome and transcriptome (Spearman ρ = 0.40), which is in line with other tissues but indicates that a relatively low amount of variation in protein levels is explained by the variation in transcript levels. Of 71 shared targets that differed with age, eight were associated with bone mineral density in previous GWAS, including understudied targets Asrgl1 and Timp2. We used complementary RNA in situ hybridization to confirm that Asrgl1 and Timp2 had reduced expression in osteoblasts/osteocytes in old bones. We also found evidence for reduced TGF-beta signaling with aging, in particular Tgfb2. Next, we defined proteomic changes following mechanical loading. At the protein level, bone differed more with age than with loading, and aged bone had fewer loading-induced changes. Overall, our findings underscore the need for complementary protein-level assays in skeletal biology research.

The prediction model of fall risk for the elderly based on gait analysis

INTRODUCTION

Early screening and identification are crucial for fall prevention, and developing a new method to predict fall risk in the elderly can address the current lack of objectivity in assessment tools.

METHODS

A total of 132 elderly individuals over 80 years old residing in some nursing homes in Shanghai were selected using a convenient sampling method. Fall history information was collected, and gait data during a 10-meter walk were recorded. Logistic regression was employed to establish the prediction model, and a nomogram was used to assess the importance of the indicators. The Bootstrap method was utilized for internal validation of the model, while the verification set was used for external validation. The predictive performance of the model was evaluated using the area under the ROC curve, calibration curve, and decision curve analysis (DCA) to assess clinical benefits.

RESULTS

The incidence of falls in the sample population was 36.4%. The Tinetti Gait and Balance Test (TGBT) score (OR = 0.832, 95% CI: 0.734,0.944), stride length (OR = 0.007, 95% CI: 0.000,0.104), difference in standing time (OR = 0.001, 95% CI: 0.000,0.742), and mean stride time (OR = 0.992, 95% CI:0.984,1.000) were identified as significant factors. The area under the ROC curve was 0.878 (95% CI: 0.805, 0.952), with a sensitivity of 0.935 and specificity of 0.726. The Brier score was 0.135, and the Hosmer-Lemeshow test (χ2 = 10.650, P = 0.222) indicated a good fit and calibration of the model.

CONCLUSION

The TGBT score, stride length, difference in standing time, and stride time are all protective factors associated with fall risk among the elderly. The developed risk prediction model demonstrates good discrimination and calibration, providing valuable insights for early screening and intervention in fall risk among older adults.

Bone mineral density in osseointegration implant surgery: A review of current studies (Review)

Osseointegration implant (OI) surgery is the latest rehabilitation technology for amputees, where a bone-anchored implant obviates the limitations of traditional socket prostheses. The bone mineral density (BMD) in the periprosthetic and other anatomical regions can be used to assess bone remodelling following OI surgery. Currently, limited studies have used BMD measurements in reporting post-operative OI outcomes and the association between the maintenance of BMD and implant efficacy has remained elusive. This review captured and analysed all studies that have reported the BMD as an objective outcome measure in patients with trans-femoral or trans-tibial OI. The PubMed, Medline, Scopus and Web of Science databases were searched using the terms 'amputation', 'osseointegration' and 'bone mineral density'. A total of 6 studies involving human participants were included for analysis. All studies used dual X-ray absorptiometry and/or X-rays for measuring BMD. Rehabilitation of trans-femoral or trans-tibial amputation using OI may help restore healthy BMD by enabling physiological bone loading. However, there is a low correlation between the BMD around the OI and the success of OI surgery or the risk of periprosthetic fractures. This review summarises the current evidence on BMD assessment in OI for lower limb amputee rehabilitation. Despite the great variability in the results, the available evidence suggests that OI may help restore BMD following surgery. The limited evidence calls for further investigation, as well as the development of a standard BMD measurement protocol.

Cardiometabolic health in people with HIV: expert consensus review

OBJECTIVES

To develop consensus data statements and clinical recommendations to provide guidance for improving cardiometabolic health outcomes in people with HIV based on the knowledge and experience of an international panel of experts.

METHODS

A targeted literature review including 281 conference presentations, peer-reviewed articles, and background references on cardiometabolic health in adults with HIV published between January 2016 and April 2022 was conducted and used to develop draft consensus data statements. Using a modified Delphi method, an international panel of 16 experts convened in workshops and completed surveys to refine consensus data statements and generate clinical recommendations.

RESULTS

Overall, 10 data statements, five data gaps and 14 clinical recommendations achieved consensus. In the data statements, the panel describes increased risk of cardiometabolic health concerns in people with HIV compared with the general population, known risk factors, and the potential impact of antiretroviral therapy. The panel also identified data gaps to inform future research in people with HIV. Finally, in the clinical recommendations, the panel emphasizes the need for a holistic approach to comprehensive care that includes regular assessment of cardiometabolic health, access to cardiometabolic health services, counselling on potential changes in weight after initiating or switching antiretroviral therapy and encouraging a healthy lifestyle to lower cardiometabolic health risk.

CONCLUSIONS

On the basis of available data and expert consensus, an international panel developed clinical recommendations to address the increased risk of cardiometabolic disorders in people with HIV to ensure appropriate cardiometabolic health management for this population.

Molecular insights of exercise therapy in disease prevention and treatment

Despite substantial evidence emphasizing the pleiotropic benefits of exercise for the prevention and treatment of various diseases, the underlying biological mechanisms have not been fully elucidated. Several exercise benefits have been attributed to signaling molecules that are released in response to exercise by different tissues such as skeletal muscle, cardiac muscle, adipose, and liver tissue. These signaling molecules, which are collectively termed exerkines, form a heterogenous group of bioactive substances, mediating inter-organ crosstalk as well as structural and functional tissue adaption. Numerous scientific endeavors have focused on identifying and characterizing new biological mediators with such properties. Additionally, some investigations have focused on the molecular targets of exerkines and the cellular signaling cascades that trigger adaption processes. A detailed understanding of the tissue-specific downstream effects of exerkines is crucial to harness the health-related benefits mediated by exercise and improve targeted exercise programs in health and disease. Herein, we review the current in vivo evidence on exerkine-induced signal transduction across multiple target tissues and highlight the preventive and therapeutic value of exerkine signaling in various diseases. By emphasizing different aspects of exerkine research, we provide a comprehensive overview of (i) the molecular underpinnings of exerkine secretion, (ii) the receptor-dependent and receptor-independent signaling cascades mediating tissue adaption, and (iii) the clinical implications of these mechanisms in disease prevention and treatment.

Bone mineral density after exercise training in patients with chronic kidney disease stages 3 to 5: a sub-study of RENEXC-a randomized controlled trial

Background

We evaluated the effects of 12 months of exercise training on bone mineral density (BMD) in patients with chronic kidney disease (CKD) stages 3-5 not on kidney replacement therapy (KRT).

Methods

A total of 151 patients were randomized to 12 months of either balance or strength training, both together with endurance training. Some 112 patients completed and 107 (69 men, 38 women) were analysed, with a mean age 66 ± 13.5 years and 31% having diabetes. The exercise training was self-administered, prescribed and monitored by a physiotherapist. Total body, hip and lumbar BMD, T score and Z score were measured at baseline and after 12 months using dual energy X-ray absorptiometry.

Results

Both groups showed increased physical performance. The prevalence of osteoporosis and osteopenia was unchanged. The strength group (SG) decreased total body BMD (P < .001), the balance group (BG) increased total body T score (P < .05) and total body Z score (P < .005). Total body ΔT score was negative in the SG and unchanged in the BG (P < .005). Total body ΔZ score was negative in the SG and positive in the BG (P < .001). The proportion of progressors measured by ΔT (P < .05) and ΔZ scores (P < .05) was significantly lower in the BG compared with the SG. In multivariate logistic regression analysis, belonging to the BG was the only factor with a lower risk of deterioration of total body BMD, T and Z scores.

Conclusions

Twelve months of balance training together with endurance training seemed to be superior to strength training in maintaining and improving BMD in patients with CKD not on KRT.

Mechanosensitivity and mechanotransductive properties of osteoclasts

Mechanical loading is essential for maintaining bone health. Here, we aimed to investigate the role of ATP and ADP in the mechanotransduction of bone-resorptive osteoclasts. Single osteoclast in primary cultures from 10 to 12-wk-old mice was mechanically stimulated by a gentle touch with a micropipette. Changes in cytosolic free calcium [Ca2+]i were analyzed in Fura-2 loaded osteoclasts. The cell injury was assessed by analyzing the cellular Fura-2 loss and classified as severe or mild using k-means. Osteoclasts responded to mechanical stimuli with transient calcium elevation (primary responders) and transduced these signals to neighboring cells, which responded with delayed calcium elevations (secondary responders). Severely injured osteoclasts had higher calcium transients than mildly injured cells. Fluid shear stress similarly induced reversible cell injury in osteoclasts. Secondary responses were abolished by treatment with A-804598, a specific inhibitor of P2X7, but not suramin, a broad P2 receptor blocker. Osteoclasts responded to ATP and ADP with concentration-dependent changes in [Ca2+]i. We performed osteoclast micropipette stimulation in the presence of phosphoenolpyruvate and pyruvate kinase which converted all ADP in solution to ATP, or with hexokinase converting all ATP to ADP. Osteoclasts with mild membrane injury demonstrated similar calcium responses in ATP and ADP-rich environments. However, when the mechanotransductive signal to severe osteoclast injury was converted to ADP, the fraction of secondary responders and their [Ca2+]i amplitude was higher. This study suggests the importance of osteoclast mechanobiology and the role of ADP-mediated signaling in conditions of altered mechanical loading associated with bone loss.NEW & NOTEWORTHY Osteoclasts are rarely considered as cells that participate in mechanical signaling in bone. We show that osteoclasts are capable of sensing and transmitting mechanical signals to neighboring cells. Mechanical stimulation commonly induces minor repairable membrane injury in osteoclasts. ATP and especially ADP were found to play important roles in the mechanoresponsiveness of osteoclasts. This study highlights the importance of osteoclast mechanobiology especially in conditions of altered mechanical loading associated with bone loss, such as in microgravity.

Bone mineral density fall during aromatase inhibitor treatment may predict lower breast cancer recurrence

PURPOSE

Aromatase inhibitors (AIs) are associated with reduction in bone mineral density (BMD). The use of bone strengthening agents zoledronic acid and denosumab are associated with improved breast cancer outcomes for post-menopausal patients treated with AIs. This study investigates whether change in BMD with AI therapy is associated with breast cancer recurrence.

METHODS

A cohort of patients treated at a single institution diagnosed with hormone receptor-positive breast cancer with baseline BMD and subsequent BMD test while receiving adjuvant aromatase inhibitor therapy were studied. Demographic, treatment and outcome data was obtained. Simple and multiple linear regression analysis was performed to investigate predictors of annual percent BMD change at the LS and hip. Univariate and multivariate Cox proportional hazards modelling were undertaken to investigate predictors of breast cancer recurrence.

RESULTS

353 patients eligible patients were identified. In multivariate analysis of lumbar spine BMD change, the difference between those in quartile 1, which showed the greatest reduction in BMD, and quartile 3, with substantially less reduction, was significant (HR = 3.02, 95% CI 1.15-7.90 p = 0.025). Hip BMD reduction was also not significantly associated with breast cancer recurrence. The two quartiles with the least reduction in hip BMD showing a non-significant reduced risk of recurrence relative to the quartile with the greatest (p = 0.10).

CONCLUSIONS

The findings suggest an association may exist between lumbar spine BMD change and breast cancer recurrence for patients treated with adjuvant AI. Further research is required to determine whether BMD change can be utilised as a biomarker.

Spine, hip, and femoral neck bone mineral density in relation to vegetarian type and status among Taiwanese adults

We determined the association of vegetarian type and status with bone mineral density (BMD) Z-scores at the spine, hip, and femoral neck. Compared to non-vegetarians, current vegetarians, especially vegans, lacto-vegetarians, and lacto-ovo-vegetarians had lower Z-scores at multiple sites. Sole reliance on a vegetarian diet might be detrimental to the bone.

PURPOSE

The impact of vegetarian diets on BMD is contentious. We determined the association of vegetarian type and status with the spine, hip, and femoral neck BMD Z-scores.

METHODS

We analyzed data from 20,110 Taiwan Biobank volunteers. BMD was measured using dual-energy X-ray absorptiometry (DXA). The vegetarian status (non-, former, and current vegetarians) and type (non-vegetarians, ovo-vegetarians, lacto-vegetarians, lacto-ovo-vegetarians, and vegans) were determined using questionnaires.

RESULTS

The participants consisted of 12,910 women and 7200 men, with a mean age of 55.5 years. Based on vegetarian status (reference: non-vegetarians), current vegetarians had significantly lower BMD Z-scores at the spine (unstandardized regression coefficient, B =  - 0.195, p = 0.006), left hip (B =  - 0.125, p = 0.008), and right hip (B =  - 0.100, p = 0.027), respectively. Based on vegetarian status and type (reference: non-vegetarians), current vegans and non-vegans had notably lower BMD Z-scores at specific skeletal sites. For non-vegans, the BMD Z-scores were significant at the spine (B = -0.184, p = 0.010), left hip (B =  - 0.124, p = 0.010), and left femoral neck (B =  - 0.125, p = 0.012). For current vegans, however, the BMD Z-scores were significant only at the right hip (B =  - 0.232; p = 0.028). Nonetheless, after stratifying vegetarian diet into more subgroups, current vegans exhibited a significant reduction in BMD Z-scores at the spine and right hip, with B-coefficients of - 0.326 and - 0.238, respectively. Current lacto-vegetarians also had significantly lower Z-scores (p < 0.05) at the spine (B =  - 0.459), left hip (B =  - 0.313), and right hip (B =  - 0.214). Moreover, current lacto-ovo-vegetarians had significantly lower Z-scores at the spine (B =  - 0.175) and left hip (B =  - 0.115).

CONCLUSION

Current vegetarians, particularly vegans, lacto-vegetarians, and lacto-ovo-vegetarians, demonstrated significantly lower BMD Z-scores at various skeletal sites compared to non-vegetarians. Sole reliance on a vegetarian diet might be detrimental to the bone.

P1NP and β-CTX-1 Responses to a Prolonged, Continuous Running Bout in Young Healthy Adult Males: A Systematic Review with Individual Participant Data Meta-analysis

BACKGROUND

Circulating biomarkers of bone formation and resorption are widely used in exercise metabolism research, but their responses to exercise are not clear. This study aimed to quantify group responses and inter-individual variability of P1NP and β-CTX-1 after prolonged, continuous running (60-120 min at 65-75% V̇O2max) in young healthy adult males using individual participant data (IPD) meta-analysis.

METHODS

The protocol was designed following PRISMA-IPD guidelines and was pre-registered on the Open Science Framework prior to implementation ( https://osf.io/y69nd ). Changes in P1NP and β-CTX-1 relative to baseline were measured during, immediately after, and in the hours and days following exercise. Typical hourly and daily variations were estimated from P1NP and β-CTX-1 changes relative to baseline in non-exercise (control) conditions. Group responses and inter-individual variability were quantified with estimates of the mean and standard deviation of the difference, and the proportion of participants exhibiting an increased response. Models were conducted within a Bayesian framework with random intercepts to account for systematic variation across studies.

RESULTS

P1NP levels increased during and immediately after running, when the proportion of response was close to 100% (75% CrI: 99 to 100%). P1NP levels returned to baseline levels within 1 h and over the next 4 days, showing comparable mean and standard deviation of the difference with typical hourly (0.1 ± 7.6 ng·mL-1) and daily (- 0.4 ± 5.7 ng·mL-1) variation values. β-CTX-1 levels decreased during and up to 4 h after running with distributions comparable to typical hourly variation (- 0.13 ± 0.11 ng·mL-1). There was no evidence of changes in β-CTX-1 levels during the 4 days after the running bout, when distributions were also similar between the running data and typical daily variation (- 0.03 ± 0.10 ng·mL-1).

CONCLUSION

Transient increases in P1NP were likely biological artefacts (e.g., connective tissue leakage) and not reflective of bone formation. Comparable small decreases in β-CTX-1 identified in both control and running data, suggested that these changes were due to the markers' circadian rhythm and not the running intervention. Hence, prolonged continuous treadmill running did not elicit bone responses, as determined by P1NP and β-CTX-1, in this population.

Exercise training and bone mineral density in postmenopausal women: an updated systematic review and meta-analysis of intervention studies with emphasis on potential moderators

The aim of this systematic review and meta-analysis was (1) to determine exercise effects on bone mineral density (BMD) in postmenopausal women and (2) to address the corresponding implication of bone and menopausal status or supervision in postmenopausal women. A comprehensive search of eight electronic databases according to the PRISMA statement up to August 9, 2022, included controlled exercise trials ≥ 6 months. BMD changes (standardized mean differences: SMD) at the lumbar spine (LS), femoral neck (FN), and total hip (TH) were considered as outcomes. Study group comparisons were conducted for osteopenia/osteoporosis versus normal BMD, early versus late postmenopausal women, and predominantly supervised versus predominantly non-supervised study arms. We applied an inverse heterogeneity (IVhet) model. In summary, 80 studies involving 94 training and 80 control groups with a pooled number of 5581 participants were eligible. The IVhet model determined SMDs of 0.29 (95% CI: 0.16-0.42), 0.27 (95% CI: 0.16-0.39), and 0.41 (95% CI: 0.30-0.52) for LS, FN, and THBMD, respectively. Heterogeneity between the trial results varied from low (I2 = 20%, TH BMD) to substantial (I2 = 68%, LS-BMD). Evidence for publication bias/small study effects was negligibly low (FN-, TH-BMD) to high (LSBMD). We observed no significant differences (p > .09) for exercise effects on LS-, FN-, or TH-BMD-LS between studies/study arms with or without osteopenia/osteoporosis, early versus late postmenopausal women, or predominantly supervised versus non-supervised exercise programs. Using robust statistical methods, the present work provides further evidence for a positive effect of exercise on BMD in postmenopausal women. Differences in bone status (osteopenia/osteoporosis versus normal bone), menopausal status (early versus late postmenopausal), and supervision (yes versus no) did not significantly affect the exercise effects on BMD at LS or proximal femur.

Correlation of bone density measured on CT chest with the severity of COVID-19 infection: A retrospective study

PURPOSE

This retrospective study investigated the correlation between bone mineral density (BMD) and COVID-19 severity among COVID-19 patients who underwent chest computed tomography (CT) scans.

METHODS

This study was carried out at the King Abdullah Medical Complex in Jeddah, Saudi Arabia, one of the largest COVID-19 centers in the western province. All adult COVID-19 patients who had a chest CT between January 2020 and April 2022 were included in the study. The pulmonary severity scores (PSS) and vertebral BMD measurements were obtained from the patient's CT chest. Data from the patients' electronic records were collected.

RESULTS

The average patient age was 56.4 years, and most (73.5%) patients were men. Diabetes (n = 66, 48.5%), hypertension (n = 56, 41.2%), and coronary artery disease (n = 17, 12.5%) were the most prevalent comorbidities. Approximately two-thirds of hospitalized patients required ICU admission (64%), and one-third died (30%). The average length of stay in the hospital was 28.4 days. The mean CT pneumonia severity score (PSS) was 10.6 at the time of admission. Patients with lower vertebral BMD (< = 100) numbered 12 (8.8%), while those with higher vertebral BMD (>100) numbered 124 (91.2%). Only 46 out of the total survived patients (n = 95) were admitted to the ICU versus all deceased (P<0.01). The logistic regression analysis revealed that an elevated PSS upon admission resulted in a reduced chance of survival. Age, gender, and BMD did not predict survival chances.

CONCLUSION

The BMD had no prognostic advantage, and the PSS was the significant factor that could have predicted the outcome.

Reprint of: Community-level age bias and older adult mortality

RATIONALE

As the older adult population increases, understanding the health effects of bias against older adults is increasingly important. Whether structural forms of age bias predict worse health has received limited attention.

OBJECTIVE

We hypothesized that communities with greater age bias would have higher mortality among residents aged 65 and older. We expected the association to be unique to age bias, rather than general bias (i.e., sexual minority and racial bias), and that the age bias-mortality association would be strongest in predominantly White and younger communities.

METHODS

Explicit and implicit attitudes toward older adults (N = 1,001,735), sexual minorities (N = 791,966), and Black Americans (N = 2,255,808) were drawn from Project Implicit. Post-stratification relative to U.S. Census demographics was executed to improve the representativeness of county-level explicit and implicit bias estimates. County older adult mortality, estimated cross-sectionally with and longitudinally relative to bias scores, served as outcomes. Models controlled for relevant county-level covariates (e.g., median age) and included all U.S. counties (N = 3142).

RESULTS

Contrary to hypotheses but consistent with prior work, explicit age bias was cross-sectionally and longitudinally associated with lower mortality, over and above covariates and generalized community bias. The explicit age bias-lower mortality association only emerged in younger counties but did not depend on county ethnic composition. Implicit age bias was unassociated with outcomes. Post-hoc analyses supported that ageist communities may be associated with better health across the lifespan. Explicit age bias predicted lower mortality in young and middle adulthood; better mental health in middle adulthood, but not exercise or self-rated health, mediated the explicit age bias-older adult mortality association.

CONCLUSIONS

Results highlight the uniqueness of older age relative to other stigmatized identities. Further examination of the association of community-level age bias with better health may improve longevity for all communities.

Comparative efficacy different resistance training protocols on bone mineral density in postmenopausal women: A systematic review and network meta-analysis

Objective: To systematically review the effects of different resistance training (RT) protocols on bone mineral density (BMD) in postmenopausal women. Methods: Randomized controlled trials (RCTs) on the resistance training in improving bone mineral density for postmenopausal women were searched in databases including ProQuest, PubMed, Cochrane Library, Embase, and Web of Science. The retrieval time range was from the establishment of the database to May 2022. The included literature was independently screened and relevant data was extracted by two reviewers. The systematic review followed the Joanna Briggs Institute (JBI) methodology for reviews of quantitative evidence. Quality of risk was assessed using the Physical Therapy Evidence Database (PEDro) scale, risk of bias was assessedusing the Cochrane RoB2 tool and a network Meta-analysis was performed on the data using Stata 16.0. Results: A total of 19 studies, which included 919 subjects, were eventually acquired. The results of the network Meta-analysis showed that moderate intensity resistance training was superior in improving lumbar spine bone mineral density (LS BMD) and femoral neck bone mineral density (FN BMD) compared to the control group (as per usual daily life), with a statistically significant difference (p < 0.05). There was, however, no statistically significant difference between the groups in terms of increasing total hip bone mineral density (TH BMD) and trochanter bone mineral density (Troch BMD), although moderate intensity training tends to increase bone mineral density (p > 0.05). In addition, when training frequency is taken into consideration, 3 days/week of moderate intensity training (3MI) was superior to 2 days/week (2MI) in improving lumbar spine bone mineral density , and moderate intensity training was superior to low and high intensity resistance trainings at training frequency of 3 day/week, with statistically significant differences (p < 0.05). The cumulative probability ranking results indicated that 3MI was the optimal option in improving lumbar spine, femoral neck, total hip and Troch bone mineral density. Subgroup analyses combining interventions time showed that for lumbar spine and femoral neck bone mineral density, 3MI protocol with intervention duration within 1 year (≤48 weeks) had a significant advantage over other interventions, while this advantage was no longer significant with the intervention duration of more than 1 year (>48 weeks). Conclusion: Current evidence shows that moderate intensity resistance training for 3 days/week can be preferred clinically to improve bone mineral density in postmenopausal women, and it is recommended that the duration of the same training should not exceed 1 year. Nevertheless, more high-quality studies are needed to verify the above conclusion.

Effect of Yi Jin Jing exercise plus Elastic Band Resistance exercise on overall bone mineral density in postmenopausal women

OBJECTIVES

This work aimed to study the effects of Yi Jin Jing plus Elastic Band Resistance exercise on bone mineral density at all parts of the body and bone metabolism index levels in postmenopausal women.

DESIGN

Randomized controlled trial.

METHODS

Forty postmenopausal women were randomly assigned equally to the exercise or to the control group. The control group maintained their lifestyle behaviors unaltered, whereas the exercise group received  Yi Jin Jing plus Elastic Band Resistance exercise. The primary outcome was overall bone mineral density at each part, and the secondary one was bone metabolism indicator levels and bone mineral density on both sides.

RESULTS

The results after six months showed increased bone mineral density at all parts of the body in the exercise group (spine, P = 0.002; thighs, lumbar, and whole body, P < 0.05) and decreased bone mineral density in the control group (trunk, pelvis, and spine, P < 0.01). In particular, the decrease and increase were greater on the non-preferred (left) side than on the right side. As for bone metabolism indexes, β-Crosslaps levels reduced (P = 0.016) and a significant increase in 1,25-(OH)2-D3 (P < 0.001) can be observed in the exercise group.

CONCLUSIONS

The results suggested that Yi Jin Jing plus Elastic Band Resistance exercise could delay the overall decrease of bone mineral density in postmenopausal women, especially on the non-preferred side. It also increased bone formation metabolite levels and inhibited bone resorption metabolite levels.

Assessing safety and treatment efficacy of running on intervertebral discs (ASTEROID) in adults with chronic low back pain: protocol for a randomised controlled trial

Poor intervertebral disc (IVD) health is associated with low back pain (LBP). This 12-week parallel randomised controlled trial will evaluate the efficacy of a progressive interval running programme on IVD health and other clinical outcomes in adults with chronic LBP. Participants will be randomised to either a digitally delivered progressive interval running programme or waitlist control. Participants randomised to the running programme will receive three individually tailored 30 min community-based sessions per week over 12 weeks. The waitlist control will undergo no formal intervention. All participants will be assessed at baseline, 6 and 12 weeks. Primary outcomes are IVD health (lumbar IVD T2 via MRI), average LBP intensity over the prior week (100-point visual analogue scale) and disability (Oswestry Disability Index). Secondary outcomes include a range of clinical measures. All outcomes will be analysed using linear mixed models. This study has received ethical approval from the Deakin University Human Research Ethics Committee (ID: 2022-162). All participants will provide informed written consent before participation. Regardless of the results, the findings of this study will be disseminated, and anonymised data will be shared via an online repository. This will be the first study to evaluate whether a progressive interval running programme can improve IVD health in adults with chronic LBP. Identifying conservative options to improve IVD health in this susceptible population group has the potential to markedly reduce the burden of disease. This study was registered via the Australian New Zealand Clinical Trials Registry on 29 September 2022 (ACTRN12622001276741).

Community-level age bias and older adult mortality

RATIONALE

As the older adult population increases, understanding the health effects of bias against older adults is increasingly important. Whether structural forms of age bias predict worse health has received limited attention.

OBJECTIVE

We hypothesized that communities with greater age bias would have higher mortality among residents aged 65 and older. We expected the association to be unique to age bias, rather than general bias (i.e., sexual minority and racial bias), and that the age bias-mortality association would be strongest in predominantly White and younger communities.

METHODS

Explicit and implicit attitudes toward older adults (N = 1,001,735), sexual minorities (N = 791,966), and Black Americans (N = 2,255,808) were drawn from Project Implicit. Post-stratification relative to U.S. Census demographics was executed to improve the representativeness of county-level explicit and implicit bias estimates. County older adult mortality, estimated cross-sectionally with and longitudinally relative to bias scores, served as outcomes. Models controlled for relevant county-level covariates (e.g., median age) and included all U.S. counties (N = 3142).

RESULTS

Contrary to hypotheses but consistent with prior work, explicit age bias was cross-sectionally and longitudinally associated with lower mortality, over and above covariates and generalized community bias. The explicit age bias-lower mortality association only emerged in younger counties but did not depend on county ethnic composition. Implicit age bias was unassociated with outcomes. Post-hoc analyses supported that ageist communities may be associated with better health across the lifespan. Explicit age bias predicted lower mortality in young and middle adulthood; better mental health in middle adulthood, but not exercise or self-rated health, mediated the explicit age bias-older adult mortality association.

CONCLUSIONS

Results highlight the uniqueness of older age relative to other stigmatized identities. Further examination of the association of community-level age bias with better health may improve longevity for all communities.

Dietary inflammatory index and bone mineral density in Mexican population

Dietary inflammatory index has been associated with bone loss. In this longitudinal study, we reported that changes in dietary inflammatory index were associated with a reduction in bone mineral density of the total hip and femoral neck in males and females ≥ 45 years, but not in individuals < 45 years.

PURPOSE

Previous studies have suggested that an inflammatory environment can affect bone mineral density (BMD). However, most of the studies have been done in postmenopausal women. Thus, longitudinal studies in different age groups and sex are necessary to evaluate the longitudinal association between dietary inflammatory index (DII) and BMD in Mexican adults.

METHODS

A total of 1,486 participants of the Health Workers Cohort Study were included in this study. The DII was estimated with data retrieved through a semi-quantitative food frequency questionnaire. Total hip, femoral neck, and lumbar spine BMD were measured by dual-energy X-ray absorptiometry. Linear regression models for cross-sectional associations and fixed effects linear regression models for longitudinal association were estimated, and both models were stratified by sex and age groups (< 45 and ≥ 45 years).

RESULTS

We did not observe cross-sectional associations between DII and the different BMD sites at baseline. In contrast, women and men ≥ 45 years in the 25th quartile of changes in DII were associated with a gain of 0.067 g/cm² and 0.062 g/cm² of total hip BMD, while those in the 75th quartile of DII was associated with a reduction of - 0.108 g/cm² and - 0.100 g/cm², respectively. These results were similar for femoral neck BMD in women. In contrast, we did not observe association with femoral neck BMD in men. We did not observe statistically significant changes for lumbar spine BMD.

CONCLUSION

Our data suggest that changes in the DII score are associated with changes in total hip and femoral neck BMD among Mexican population.

Is Regular Weight-Bearing Physical Activity Throughout the Lifecourse Associated with Better Bone Health in Late Adulthood?

We considered how weight-bearing physical activity (WBPA) through the lifecourse related to bone health in late adulthood in the Hertfordshire Cohort Study (HCS), a cohort of community dwelling adults born 1931-9, to identify sex-specific differences and periods critical for optimal bone health. Available questionnaire data from 258 participants (128 men and 130 women) included current reported lifestyle factors (including physical activity) and WBPA, coded as participation in WBPA aged < 18 years; aged 18-29 years; aged 30-49 years and aged ≥ 50 years. Responses were recorded as none/once a month/once a week/> once a week. Hip bone mineral density (BMD) was measured using a Lunar Prodigy DXA scanner. The mean age was 75.4 (SD 2.5) years in men and 75.7 (SD 2.6) years in women. Men reported significantly higher levels of past WBPA aged < 18 years (p = 0.006) and aged 18-29 years than women (p < 0.001). We observed greater BMD at total hip in women who reported regular WBPA at ages 18-29 years (p = 0.02) and 30-49 years (p = 0.02) compared with those who reported no WBPA (p = 0.019), after adjustment for confounders including current activity levels. In this cohort of older adults, recalled regular WBPA around the time of peak bone mass acquisition was less common in women than men, but associated with higher hip BMD in women in late adulthood.

Acute Effects of Whole-Body Electromyostimulation on Energy Expenditure at Resting and during Uphill Walking in Healthy Young Men

The effects of the different electrical frequencies of whole-body electrical stimulation (WB-EMS) on energy expenditure (EE) and the respiratory exchange ratio (RER) remain poorly understood. This study aimed to determine the effects of different WB-EMS electrical frequencies on EE and the RER during supine resting and uphill walking. A total of 10 healthy and recreationally active men (21.6 ± 3.3 years old) participated in the present study. Participants completed two testing sessions in a randomized order. In each session, a variety of impulse frequencies (1 hertz (Hz), 2 Hz, 4 Hz, 6 Hz, 8 Hz, and 10 Hz) were applied in a randomized order, allowing a 10 min passive recovery between them. Oxygen consumption and carbon dioxide production were measured to calculate EE and the RER. All frequencies increased EE at rest (all p ≤ 0.001), with 4 Hz being the frequency producing the highest increase (Δ = 8.89 ± 1.49 kcal/min), as did 6 Hz (Δ = 8.05 ± 1.52 kcal/min) and 8 Hz (Δ = 7.04 ± 2.16 kcal/min). An increment in the RER at rest was observed with 4 Hz, 6 Hz, 8 Hz and 10 Hz (all p ≤ 0.016), but not with 1 Hz and 2 Hz (p ≥ 0.923). During uphill walking, the frequency that elicited the highest increase in EE was 6 Hz (Δ = 4.87 ± 0.84 kcal/min) compared to the unstimulated condition. None of the impulse frequencies altered the RER during uphill walking. WB-EMS increases EE in healthy young men both during resting and uphill walking.

Progressive Resistance Training for Concomitant Increases in Muscle Strength and Bone Mineral Density in Older Adults: A Systematic Review and Meta-Analysis

BACKGROUND

Older adults experience considerable muscle and bone loss that are closely interconnected. The efficacy of progressive resistance training programs to concurrently reverse/slow the age-related decline in muscle strength and bone mineral density (BMD) in older adults remains unclear.

OBJECTIVES

We aimed to quantify concomitant changes in lower-body muscle strength and BMD in older adults following a progressive resistance training program and to determine how these changes are influenced by mode (resistance only vs. combined resistance and weight-bearing exercises), frequency, volume, load, and program length.

METHODS

MEDLINE/PubMed and Embase databases were searched for articles published in English before 1 June, 2021. Randomized controlled trials reporting changes in leg press or knee extension one repetition maximum and femur/hip or lumbar spine BMD following progressive resistance training in men and/or women ≥ 65 years of age were included. A random-effects meta-analysis and meta-regression determined the effects of resistance training and the individual training characteristics on the percent change (∆%) in muscle strength (standardized mean difference) and BMD (mean difference). The quality of the evidence was assessed using the Cochrane risk-of-bias tool (version 2.0) and Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) criteria.

RESULTS

Seven hundred and eighty studies were identified and 14 were included. Progressive resistance training increased muscle strength (∆ standardized mean difference = 1.1%; 95% confidence interval 0.73, 1.47; p ≤ 0.001) and femur/hip BMD (∆ mean difference = 2.77%; 95% confidence interval 0.44, 5.10; p = 0.02), but not BMD of the lumbar spine (∆ mean difference = 1.60%; 95% confidence interval - 1.44, 4.63; p = 0.30). The certainty for improvement was greater for muscle strength compared with BMD, evidenced by less heterogeneity (I2 = 78.1% vs 98.6%) and a higher overall quality of evidence. No training characteristic significantly affected both outcomes (p > 0.05), although concomitant increases in strength and BMD were favored by higher training frequencies, increases in strength were favored by resistance only and higher volumes, and increases in BMD were favored by combined resistance plus weight-bearing exercises, lower volumes, and higher loads.

CONCLUSIONS

Progressive resistance training programs concomitantly increase lower-limb muscle strength and femur/hip bone mineral density in older adults, with greater certainty for strength improvement. Thus, to maximize the efficacy of progressive resistance training programs to concurrently prevent muscle and bone loss in older adults, it is recommended to incorporate training characteristics more likely to improve BMD.

Similarities Between Disuse and Age-Induced Bone Loss

Disuse and aging are known risk factors associated with low bone mass and quality deterioration, resulting in increased fracture risk. Indeed, current and emerging evidence implicate a large number of shared skeletal manifestations between disuse and aging scenarios. This review provides a detailed overview of current preclinical models of musculoskeletal disuse and the clinical scenarios they seek to recapitulate. We also explore and summarize the major similarities between bone loss after extreme disuse and advanced aging at multiple length scales, including at the organ/tissue, cellular, and molecular level. Specifically, shared structural and material alterations of bone loss are presented between disuse and aging, including preferential loss of bone at cancellous sites, cortical thinning, and loss of bone strength due to enhanced fragility. At the cellular level bone loss is accompanied, during disuse and aging, by increased bone resorption, decreased formation, and enhanced adipogenesis due to altered gap junction intercellular communication, WNT/β-catenin and RANKL/OPG signaling. Major differences between extreme short-term disuse and aging are discussed, including anatomical specificity, differences in bone turnover rates, periosteal modeling, and the influence of subject sex and genetic variability. The examination also identifies potential shared mechanisms underlying bone loss in aging and disuse that warrant further study such as collagen cross-linking, advanced glycation end products/receptor for advanced glycation end products (AGE-RAGE) signaling, reactive oxygen species (ROS) and nuclear factor κB (NF-κB) signaling, cellular senescence, and altered lacunar-canalicular connectivity (mechanosensation). Understanding the shared structural alterations, changes in bone cell function, and molecular mechanisms common to both extreme disuse and aging are paramount to discovering therapies to combat both age-related and disuse-induced osteoporosis. © 2022 American Society for Bone and Mineral Research (ASBMR).

Effects of physical exercise on bone mineral density in older postmenopausal women: a systematic review and meta-analysis of randomized controlled trials

Osteoporosis or decreased bone mineral density (BMD) is the most important risk factor for fractures, especially in older postmenopausal women (PMW). However, the interactions between exercise training and bone mineral density are not completely understood. We evaluated the effects of physical exercise on BMD in women aged ≥ 60 years postmenopausal.

PURPOSE

This systematic review and meta-analysis sets out to determine the effects of physical exercise on BMD in older postmenopausal women.

METHODS

A systematic search was conducted in Medline, Science Direct, Cochrane, PubMed, CINAHL, Google Scholar, Scopus, and ProQuest up to December 25, 2021. Fifty-three studies, which assessed a total of 2896 participants (mean age: between 60 and 82 years), were included and analyzed using a random-effects model to estimate weighted mean differences (WMD) with 95% confidence intervals (CI).

RESULTS

The meta-analysis found that exercise training significantly (p < 0.05) increased femoral neck (WMD: 0.01 g/cm²; 95% CI, 0.00 to 0.01], p = 0.0005; I² = 57%; p < 0.0001), lumbar spine (WMD: 0.01 g/cm², 95% CI, 0.01 to 0.02], I² = 81%; p = 0.0001), and trochanter (WMD: 0.01 g/cm², 95% CI 0.00, 0.02]; p = 0.009; I² = 17%; p = 0.23). There were no significant differences between the intervention and control groups for total body and total hip BMD.

CONCLUSION

Our findings suggest that exercise training may improve bone mineral density in older PMW. This improvement is mediated by increases in the femoral neck, lumbar spine, and trochanter BMD. Further long-term studies are required to confirm these findings.

Effects of whole body vibration in postmenopausal osteopenic women on bone mineral density, muscle strength, postural control and quality of life: the T-bone randomized trial

Purpose

Osteopenia is common in postmenopausal women and effective interventions increasing or stabilizing bone mineral density (BMD) to prevent fractures are urgently needed.

Methods

Sixty-five postmenopausal women diagnosed with osteopenia (T-score between -1.0 and -2.5) were randomly assigned to either a vibration training group (VT), a resistance training group (RT), or a control group (CG). BMD T-score values (primary endpoint) were assessed at baseline (T0) and after 12 months (T12), secondary endpoints (muscle strength, postural control, and health-related quality of life) at baseline (T0), after 6 months (T6), after 12 months (T12), and as follow-up after 15 months (T15).

Results

After the intervention period, neither the VT nor the RT showed any significant changes in BMD T-score values compared to the CG. Isokinetic strength improved significantly within all training groups, with the exception of the flexors of VT at an angular velocity of 240°/s. Health-related quality of life as well as postural control improved significantly for the RT only.

Conclusions

We conclude that participants of all three groups were able to maintain their BMD. The improvements in quality of life and postural control after resistance training are nevertheless meaningful for postmenopausal osteopenic women and support the importance of regular loadings of the musculoskeletal system.

This study was retrospectively registered in January 2022 at the DRKS (S00027816) as clinical trial.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00421-022-05010-5.

Osteocytes regulate bone anabolic response to mechanical loading in male mice via activation of integrin α5

Physical mechanical stimulation can maintain and even increase bone mass. Here, we report an important role of osteocytic integrin α5 in regulating the anabolic response of bone to mechanical loading using an Itga5 conditional gene knockout (cKO) mouse model. Integrin α5 gene deletion increased apoptotic osteocytes and reduced cortical anabolic responses to tibial compression including decreased endosteal osteoblasts and bone formation, and increased endosteal osteoclasts and bone resorption, contributing to the decreased bone area fraction and biomechanical properties, leading to an enlarged bone marrow area in cKO mice. Similar disruption of anabolic responses to mechanical loading was also detected in cKO trabecular bone. Moreover, integrin α5 deficiency impeded load-induced Cx43 hemichannel opening, and production and release of PGE2, an anabolic factor, resulting in attenuated effects of the loading on catabolic sclerostin (SOST) reduction and anabolic β-catenin increase. Together, this study shows an indispensable role of integrin α5 in osteocytes in the anabolic action of mechanical loading on skeletal tissue through activation of hemichannels and PGE2-evoked gene expression. Integrin α5 could act as a potential new therapeutic target for bone loss, especially in the elderly population with impeded mechanical sensitivity.

Strength-Cognitive Training: A Systemic Review in Adults and Older Adults, and Guidelines to Promote "Strength Exergaming" Innovations

Background

Despite functional and cognitive benefits, few adults and older adults do strength training twice per week with sufficient intensity. Exercise-based active video games (exergaming) may amplify the cognitive benefits of exercise and increase adherence and motivation toward training. However, the benefits of a well-defined and monitored dose of strength training, executed simultaneously or sequentially with a cognitive element, has received little attention. In this study we have two aims: First, to systematically gather the available evidence; second, to suggest possible ways to promote strength exergaming innovations.

Methods

We systematically reviewed randomized controlled trials using simultaneous or sequent combined strength and cognitive training or strength exergaming to improve cognitive or functional outcomes in adults and older adults.

Results

After screening 1,785 studies (Google Scholar, ACM Digital Library, IEEE Xplore Library, PsycARTICLES, Scopus, Cochrane Library and PubMed) we found three eligible studies. Of the two studies using sequent strength and cognitive training, one showed improved functionality, but the other showed negative effects on cognition. The third study using simultaneous intervention, reported a positive influence on both cognition and function, when compared with either strength training alone or a control group. Moderate level of evidence was showed on GRADE analysis.

Conclusion

The existing little evidence suggests that strength and cognitive training improves cognition and function in adults and older adults. The following suggestions may help to promote further innovation: (1) ensure minimal dosage of strength training (30-60 min, 2 × /week), (2) use machine-based strength training devices to control volume and intensity (to prevent cognitive components from interfering with strength training), (3) include power training by using cognitive tasks requiring rapid reactions, and (4) add cognitive memory tasks (to extend the cognitive benefits of strength training per se), and (5) include motivational exergame elements to increase adherence.

Strong, steady and straight: UK consensus statement on physical activity and exercise for osteoporosis

Exercise and physical activity can improve bone strength and the risk of falls, which may offer benefits in the prevention and management of osteoporosis. However, uncertainty about the types of exercise that are safe and effective instigates lack of confidence in people with osteoporosis and health professionals. Existing guidelines leave some questions unresolved. This consensus statement aimed to determine the physical activity and exercise needed to optimise bone strength, reduce fall and fracture risk, improve posture and manage vertebral fracture symptoms, while minimising potential risks in people with osteoporosis. The scope of this statement was developed following stakeholder consultation. Meta-analyses were reviewed and where evidence was lacking, individual studies or expert opinion were used to develop recommendations. A multidisciplinary expert group reviewed evidence to make recommendations, by consensus when evidence was not available. Key recommendations are that people with osteoporosis should undertake (1) resistance and impact exercise to maximise bone strength; (2) activities to improve strength and balance to reduce falls; (3) spinal extension exercise to improve posture and potentially reduce risk of falls and vertebral fractures. For safety, we recommend avoiding postures involving a high degree of spinal flexion during exercise or daily life. People with vertebral fracture or multiple low trauma fractures should usually exercise only up to an impact equivalent to brisk walking. Those at risk of falls should start with targeted strength and balance training. Vertebral fracture symptoms may benefit from exercise to reduce pain, improve mobility and quality of life, ideally with specialist advice to encourage return to normal activities. Everyone with osteoporosis may benefit from guidance on adapting postures and movements. There is little evidence that physical activity is associated with significant harm, and the benefits, in general, outweigh the risks.

Exercise may impact on lumbar vertebrae marrow adipose tissue: Randomised controlled trial

BACKGROUND

Animal and human cross-sectional data suggest that bone marrow adipose tissue (MAT) may respond to mechanical loads and exercise. We conducted the first randomised controlled trial of exercise on MAT modulations in humans.

METHODS

Forty patients with chronic non-specific low back pain (NSCLBP) were enrolled in a six-month single-blinded randomised controlled trial (ACTRN12615001270505). Twenty patients loaded their spines via progressive upright aerobic and resistance exercises targeting major muscle groups (Exercise). Twenty patients performed non-weightbearing motor control training and manual therapy (Control). Testing occurred at baseline, 3-months (3mo) and 6-months (6mo). Lumbar vertebral fat fraction (VFF) was measured using magnetic resonance imaging axial mDixon sequences.

RESULTS

When compared to baseline (percent change), lumbar vertebral fat fraction (VFF; measured using magnetic resonance imaging axial mDixon sequences) was lower in Exercise at 3mo at L2 (-3.7[6.8]%, p = 0.033) and L4 (-2.6[4.1]%, p = 0.015), but not in Control. There were no between-group effects. The effects of Exercise on VFF were sex-specific, with VFF lower in men at L2, L3, L4 at 3mo and at L1, L2, L3 and L4 at 6mo (p all ≤ 0.05), but not in women. Leg and trunk lean mass were increased at 3mo in Exercise. Changes in VFF correlated significantly with changes in total fat (ρ = 0.40) and lean (ρ = -0.41) masses, but not with lumbar BMD (ρ = -0.10) or visceral adipose tissue volume (ρ = 0.23).

CONCLUSIONS

This trial provided first prospective evidence in humans that a moderate exercise intervention may modulate lumbar VFF as a surrogate measure of MAT at 3mo, yet not 6mo. The effect of exercise on MAT may be more prominent in males than females.

The mechanotransduction of MLO-Y4 cells is disrupted by the senescence-associated secretory phenotype of neighboring cells

Age-related bone loss is attributed to the accumulation of senescent cells and their increasing production of inflammatory cytokines as part of the senescence-associated secretory phenotype (SASP). In otherwise healthy individuals, osteocytes play a key role in maintaining bone mass through their primary function of responding to skeletal loading. Given that osteocytes' response to loading is known to steadily decline with age, we hypothesized that the increasing presence of senescent cells and their SASP inhibit osteocytes' response to loading. To test this hypothesis, we developed two in vitro models of senescent osteocytes and osteoblasts derived from MLO-Y4 and MC3T3 cell lines, respectively. The senescent phenotype was unique to each cell type based on distinct changes in cell cycle inhibitors and SASP profile. The SASP profile of senescent osteocytes was in part dependent on nuclear factor-κB signaling and presents a new potential mechanism to target the SASP in bone. Nonsenescent MLO-Y4 cells cultured with the SASP of each senescent cell type failed to exhibit changes in gene expression as well as ERK phosphorylation and prostaglandin E2 release. The SASP of senescent osteocytes had the largest effect and neutralizing interleukin-6 (IL-6) as part of the SASP restored osteocytes' response to loading. The loss in mechanotransduction due to IL-6 was attributed to a decrease in P2X7 expression and overall sensitivity to purinergic signaling. Altogether, these findings demonstrate that the SASP of senescent cells have a negative effect on the mechanotransduction of osteocytes and that IL-6 is a key SASP component that contributes to the loss in mechanotransduction.

Incidence of Radiolucent Lines after Cemented Total Knee Arthroplasty

BACKGROUND

Cemented Total Knee Arthroplasty (TKA) provides excellent long-term survival rates and functional results, however, radiolucent lines (RLLs) often appear during early post-operative follow-up and their incidence and clinical significance are unknown. The primary aim was to establish the incidence, location, frequency, and time taken for RLLs to appear within the first year after a primary cemented TKA with an anatomic tibial baseplate (Smith and Nephew, LEGION Total Knee System).

METHODS

This was a retrospective analysis of 135 primary cemented TKA in 131 patients over three years. We compared demographics, serial radiographs, and early clinical and functional outcomes.

RESULTS

There were 65 TKAs (48%) in 62 patients who had RLLs within the first year post-operatively. Most were females (58.8%). Mean age was 68.3 ± 7.9 years. There were 88 RLLs, with the most and second commonest location at the medial tibial baseplate (38%) and anterior femoral flange (23%). 89% were in the bone-cement interface. The largest average length of RLLs were at the anterior flange of the femoral component (1.98 ± 1.33 mm). The average time to development was 6.5 ± 4.1 months. None of these patients had infections nor required revision. Patients with RLLs did not do worse in functional and clinical scoring at 1-year.

CONCLUSION

There was a 48% incidence of physiological RLLs after cemented TKA, with the highest occurrence at the medial tibial baseplate at 38%. These radiolucent lines did not affect early post-operative clinical and functional outcomes of patients.

The effect of different training frequency on bone mineral density in older adults. A comparative systematic review and meta-analysis

Exercise frequency is a key aspect of exercise protocols. In this systematic review and meta-analysis, we determined the effect of training frequency on (areal) bone mineral density (BMD) at lumbar spine (LS) and hip. Reviewing seven electronic databases up to April 2021, we conducted a systematic review of the literature according to the PRISMA statement. Inclusion criteria were (a) controlled exercise trials (b) with at least two study arms that compared low versus high exercise frequency, (c) an intervention ≥6 months and (d) BMD assessments at lumbar spine (LS) or hip. The analysis was conducted as a mixed-effect meta-analysis and used "type of exercise" and "study duration" as moderators in subgroup analyses. Standardized mean differences (SMD) for LS- and hip-BMD changes were defined as outcome measures. Seven studies with 17 exercise groups were included in the analysis. We observed significantly higher effects of high (≥2 sessions/week) vs. low net training frequency (1-<2 sessions/week) exercise on LS- (SMD 0.55, 95%-CI: 0.20-0.90) but not hip-BMD (0.19, -0.06 to 0.45). Study duration was found to be a significant moderator for the effect of training frequency at LS- but not hip-BMD. In parallel, the type of exercise moderately influences the effect of training frequency on LS- but not on hip-BMD. We observed a superior effect of higher net training frequency on BMD. Longer exercise exposition increases this effect. Considering e.g. holidays, indisposition or other temporary absence, exercise programs on osteoporosis should provide at least 3 sessions/week/year to allow a net training frequency of more than two sessions/week. STUDY REGISTRATION: PROSPERO (CRD42021246804).

Outcomes of Tibial Plateau Fracture Surgical Fixation: a Comparative Study between Younger and Older Age Groups

BACKGROUND

Tibial plateau fractures account for approximately 8% of the fractures of the elderly. Low bone quality that is more common in the elderly is one of the major challenges in fixing fractures and may be a barrier to achieving satisfactory outcomes after a surgical fracture treatment. Accordingly, surgical fixation of tibial plateau fractures was controversial in the elderly. This study aimed to investigate and compare the clinical outcomes of surgical fixation in patients over and under 60 years of age.

METHODS

This study was conducted as a retrospective cohort study of data that were prospectively collected. In total, 48 patients who underwent surgery with open reduction and internal fixation before August 2019 were recruited and followed up at least one year after surgery. Demographic characteristics, the range of motion of the knees, visual analog scale (VAS) score of pain intensity, and the Oxford Knee Score (OKS) were obtained in this study. Furthermore, Short Form-36 (SF-36) questionnaire was used to evaluate patient satisfaction.

RESULTS

In total, 19 and 29 patients were over and under 60 years of age, respectively. According to Schatzker's classification, the most common type of fracture was type VI. The range of motion in the knees did not differ significantly between the two groups (P>0.05). Moreover, OKS and the VAS of pain intensity were not significantly different in both groups (P>0.05). In addition, SF-36 scores were not significantly different between elderly patients and the age-matched general population. However, younger patients had lower scores in the physical function and vitality scales of SF-36, compared to the age-matched general population.

CONCLUSION

Based on the results of the present study, it can be stated that increasing age did not affect the surgical outcomes of patients with tibial plateau fractures.

The effect of magnetic therapy and moderate aerobic exercise on osteoporotic patients: A randomized clinical study

BACKGROUND

Osteoporosis is a frequent musculoskeletal condition with significant complications that would be a global health problem and one of the major causes of mortality and morbidity.

OBJECTIVES

The current study aimed to ascertain the impact of pulsed magnetic therapy, aerobic exercise, and a combination of both modalities on osteoporotic female patients postthyroidectomy.

METHODS

Between May 2018 and September 2019, 45 female patients with osteoporosis were included in the randomized clinical study, their age ranged from 40 to 50 years, had thyroidectomy for at least 6 months ago, and had an inactive lifestyle for at least the previous 6 months. Patients were assigned randomly into 3 equal groups. Group A (magnetic therapy group): received routine medical treatment (bisphosphonates, calcium, and vitamin D) in addition to pulsed magnetic therapy on the hip region for 12 weeks (3 sessions/week). Group B (exercise group): received routine medical treatment plus moderate-intensity aerobic exercise for 12 weeks (3 sessions/week). Group C (combined magnetic therapy and exercise therapy group): received routine medical treatment plus pulsed magnetic therapy and moderate-intensity aerobic exercise for 12 weeks (3 sessions/week). The 3 groups were assessed for bone mineral density (BMD) at baseline by dual-energy x-ray absorptiometry and after 12 weeks of treatment.

RESULTS

The results showed that within-group analysis a statistically significant increase was reveled (P < .05) for BMD in the 3 studied groups. Comparing the results among the 3 tested groups revealed a significant increase (P < .05) in posttesting mean values of BMD in group (C) compared to group (A) and group (B). No significant statistical difference in BMD means values between the 2 groups (A) and (B) after testing was detected.

CONCLUSION

Combination of both pulsed magnetic therapy and moderate-intensity aerobic exercise showed significant improvement in BMD at the hip region than using any of the 2 modalities alone.

Exercise attenuates bone mineral density loss during diet-induced weight loss in adults with overweight and obesity: A systematic review and meta-analysis

BACKGROUND

Weight-loss-induced fat loss improves cardiometabolic health in individuals with overweight and obesity; however, weight loss can also result in bone loss and increased fracture risk. Weight-loss-induced bone loss may be attenuated with exercise. Our aim was to compare changes in bone mineral density (BMD) in adults with overweight and obesity who undertook diet-induced weight loss alone or in combination with exercise.

METHODS

We included randomized controlled trials (RCTs) in adults with overweight or obesity (aged ≥18 years; body mass index ≥25 kg/m2) that prescribed diet-induced weight loss alone or in combination with supervised exercise, and measured any bone structural parameters. Risk of bias was assessed using the Cochrane Risk of Bias tool. Random-effects meta-analyses determined mean changes and net mean differences (95% confidence intervals (95%CIs)) in the percentage of areal BMD (aBMD) change between groups.

RESULTS

We included 9 RCTs. Diet-induced weight loss led to significant losses in femoral neck aBMD (mean change: -1.73% (95%CI: -2.39% to -1.07%), p < 0.001) and total hip aBMD (-2.19% (95%CI: -3.84% to -0.54%), p = 0.009). Femoral neck aBMD losses were significantly greater in the diet-induced weight loss group compared to the exercise plus diet-induced weight loss group (net difference: -0.88% (95%CI: -1.73% to -0.03%)); however, there were no differences in aBMD changes at any other skeletal site: total hip (-1.96% (95%CI: -4.59% to 0.68%)) and lumbar spine (-0.48% (95%CI: -1.81% to 0.86%)). aBMD changes did not differ significantly according to exercise modality (resistance exercise, aerobic exercise, or a combination of the two) during diet-induced weight loss.

CONCLUSION

Diet-induced weight loss led to greater femoral neck bone loss compared to diet-induced weight loss plus exercise. Bone loss at the total hip and lumbar spine was not attenuated by exercise during diet-induced weight loss. The lack of consistent skeletal benefits may be due to the insufficient duration and/or training intensities of most exercise interventions. Additional RCTs with appropriate, targeted exercise interventions should be conducted.

The effect of exercise for improving bone health in cancer survivors - A systematic review and meta-analysis

OBJECTIVE

To evaluate the effectiveness of exercise for improving bone-related outcomes among cancer survivors.

DESIGN

Systematic review and meta-analysis.

METHODS

An electronic search using the following databases: SPORTDiscus, Science Direct, CINAHL, MEDLINE, Cochrane, Pubmed, Ebscohost, ProQuest Nursing and Allied Health Source. Randomised, controlled, exercise trials involving cancer survivors were eligible. Effect data on bone mineral content (BMC) and density (BMD) outcomes were extracted. Risk of bias was assessed using the Physiotherapy Evidence Database tool. Standardised mean differences (SMD) were calculated to compare differences between exercise and usual care. Subgroup analyses were conducted to assess whether effect differed by exercise mode, intervention length, supervision, treatment, cancer type and risk of bias.

RESULTS

Twenty-six trials were included, with intervention durations ranging between 12 weeks and 2 years. Most trials involved breast cancer (n = 13, 50%), and most interventions were supervised (n = 18, 69%) and evaluated mixed-mode (i.e., combined aerobic and resistance) exercise (n = 13, 50%). Significant effects in favour of exercise (aerobic, resistance, mixed-mode and other exercise) were observed for whole body BMD, hip BMD, trochanter BMD and femoral neck BMD (SMD range: 0.19-0.39, all p < 0.05) compared to usual care.

CONCLUSION

Participation in various modes (aerobic, resistance, mixed-mode and other) of supervised and unsupervised exercise is associated with improvements in BMD. The present results provide evidence for clinicians and other health care professionals (e.g., exercise physiologists and physiotherapists) to recommend exercise for cancer survivors to prevent bone loss during and following treatment.

Towards a Standard Approach to Assess Tibial Bone Loss Following Total Knee Arthroplasty

Long-term implant failure in the form of aseptic loosening and periprosthetic fracture is the most common cause of revision procedures in total knee arthroplasty (TKA). While early loosening can often be attributed to failure of primary fixation, late implant failure could be associated with loss of fixation secondary to bone resorption, as a result of stress shielding in the proximal tibia. This current review study was performed to identify the clinical effects of different implant-, patient-, and surgery-related biomechanical factors on TKA-related tibial bone loss in clinical reality. Implant-related factors considered were the fixation method, and the implant type, geometry, and stiffness. In terms of patient characteristics, the effects of age, sex, knee alignment, bone density, body weight, and activity level were analyzed. The clinical literature on these topics mostly concerned longitudinal radiographic studies investigating the effect of a single factor on changes in the proximal tibia over time using bone densitometry. Implant stiffness, implant geometry and knee alignment were the only factors consistently found to affect regional bone density changes over time. Each clinical study used its own specific study design, with different definitions used for the baseline density, time points of baseline and follow-up measurements, and regions of interest. Due to the differences in study design, direct comparison between the clinical impact of different biomechanical factors was not possible. Based on the findings over the densitometry studies, a standardized guideline was proposed to allow reliable comparison between consistently reported outcome of future radiographic TKA studies.

Estimates of the effects of physical activity on osteoporosis using multivariable Mendelian randomization analysis

This study estimates causality of physical activity (PA) on bone mineral density (BMD) by conducting multivariable Mendelian randomization (MR). The findings suggest that habitual vigorous PA increases lumbar spine BMD, and higher overall acceleration average would improve forearm BMD. The results could promote PA intervention targeting individuals with optimized type.

INTRODUCTION

Evidence from epidemiologic studies showed type, frequency, and duration of PA influenced BMD. However, these observational studies may be confounded by many factors, resulting in spurious associations. We aimed to conduct multivariable MR to estimate the causal effect of self-reported and device-measured PA on osteoporosis.

METHODS

Three self-reported and two device-measured PA-related traits were selected as exposures. Outcomes were BMD at different skeletal sites: femoral neck BMD (FN BMD), lumbar spine BMD (LS BMD), and forearm BMD (FA BMD). Exposure datasets were obtained from UK Biobank with total 377,234 subjects. Outcome datasets were obtained from GEFOS consortium with 53,236 subjects. Standard MR analysis and multivariable MR were conducted to assess the total and direct causal effect of PA on BMD.

RESULTS

For self-reported PA, inverse-normalized moderate-to-vigorous had a direct causal effect on FN BMD independently (β = - 1.116 (95% confidence interval, 95%CI: - 2.210, - 0.023), P = 0.045); vigorous PA showed a direct effect (β = 3.592 (95%CI: 0.310, 6.874), P = 0.032) on LS BMD independently. While overall acceleration average and fraction of accelerations both had a direct causal effect on FA BMD independently.

CONCLUSIONS

Habitual vigorous PA could increase LS BMD. Individuals with higher overall acceleration average would have a higher FA BMD.

Association between Visceral and Bone Marrow Adipose Tissue and Bone Quality in Sedentary and Physically Active Ovariectomized Wistar Rats

Background: Obesity is considered protective for bone mass, but this view has been progressively challenged. Menopause is characterized by low bone mass and increased adiposity. Our aim was to determine how visceral and bone marrow adiposity change following ovariectomy (OVX), how they correlate with bone quality and if they are influenced by physical activity. Methods: Five-month-old Wistar rats were OVX or sham-operated and maintained in sedentary or physically active conditions for 9 months. Visceral and bone marrow adiposity as well as bone turnover, femur bone quality and biomechanical properties were assessed. Results: OVX resulted in higher weight, visceral and bone marrow adiposity. Visceral adiposity correlated inversely with femur Ct.Th (r = −0.63, p < 0.001), BV/TV (r = −0.67, p < 0.001), Tb.N (r = −0.69, p < 0.001) and positively with Tb.Sp (r = 0.58, p < 0.001). Bone marrow adiposity also correlated with bone resorption (r = 0.47, p < 0.01), bone formation rate (r = −0.63, p < 0.01), BV/TV (r = −0.85, p < 0.001), Ct.Th (r = −0.51, p < 0.0.01), and with higher empty osteocyte lacunae (r = 0.39, p < 0.05), higher percentage of osteocytes with oxidative stress (r = 0.64, p < 0.0.01) and lower femur maximal stress (r = −0.58, p < 0.001). Physical activity correlated inversely with both visceral (r = −0.74, p < 0.01) and bone marrow adiposity (r = −0.92, p < 0.001). Conclusions: OVX increases visceral and bone marrow adiposity which are associated with inferior bone quality and biomechanical properties. Physical activity could contribute to reduce adipose tissue and thereby improve bone quality.

Relationship between bone strength index of the hemiparetic tibial diaphysis and muscle strength in people with chronic stroke: influence of muscle contraction type and speed

This study was conducted to examine the association between the tibial bone strength index and leg muscle strength of different contraction types and speeds among people with chronic stroke. We found that concentric muscle power at moderate speed was more associated with tibial bone strength index than other types.

INTRODUCTION

To compare the influence of muscle strength of different contraction types and speeds on the bone strength index of tibial diaphysis in people with chronic stroke.

METHODS

Eighty individuals with chronic stroke (age: 62.6 ± 8.0 years; men/women: 46/34; post-stroke duration: 9.0 ± 5.4 years) underwent scanning of the tibia at the 66% site on both sides using peripheral quantitative computed tomography. Each participant was also evaluated for isometric and dynamic (at 60°/s and 120°/s) strength of knee flexors/extensors and ankle dorsiflexors/plantarflexors using an isokinetic dynamometer. For a given contraction type and speed, the strength values of the four muscle groups were summed to yield a composite score. Multiple regression analysis was used to identify the association of the percent side-to-side difference (%SSD) in tibial polar-stress-strain index (p-SSI) with %SSD in muscle strength of different contraction types and speeds.

RESULTS

The p-SSI and all muscle strength parameters on the paretic side had lower values than the non-paretic side (p ≤ 0.001). The %SSD in concentric muscle power at angular speed of 60°/s (R² = 0.317, p = 0.006) and 120°/s (R² = 0.298, p = 0.020) remained independently associated with that in p-SSI, after controlling for age, sex, body mass index, post-stroke duration, motor impairment, spasticity, and physical activity level. The effect of isometric strength and eccentric muscle power was not significant in multivariate analysis.

CONCLUSIONS

Concentric muscle power was more predictive of %SSD in p-SSI at the tibial diaphysis than other contraction types and may be an important target for intervention to promote bone health in people with chronic stroke.

Muscle-Bone Crosstalk in Chronic Kidney Disease: The Potential Modulatory Effects of Exercise

Chronic kidney disease (CKD) is a prevalent worldwide public burden that increasingly compromises overall health as the disease progresses. Two of the most negatively affected tissues are bone and skeletal muscle, with CKD negatively impacting their structure, function and activity, impairing the quality of life of these patients and contributing to morbidity and mortality. Whereas skeletal health in this population has conventionally been associated with bone and mineral disorders, sarcopenia has been observed to impact skeletal muscle health in CKD. Indeed, bone and muscle tissues are linked anatomically and physiologically, and together regulate functional and metabolic mechanisms. With the initial crosstalk between the skeleton and muscle proposed to explain bone formation through muscle contraction, it is now understood that this communication occurs through the interaction of myokines and osteokines, with the skeletal muscle secretome playing a pivotal role in the regulation of bone activity. Regular exercise has been reported to be beneficial to overall health. Also, the positive regulatory effect that exercise has been proposed to have on bone and muscle anatomical, functional, and metabolic activity has led to the proposal of regular physical exercise as a therapeutic strategy for muscle and bone-related disorders. The detection of bone- and muscle-derived cytokine secretion following physical exercise has strengthened the idea of a cross communication between these organs. Hence, this review presents an overview of the impact of CKD in bone and skeletal muscle, and narrates how these tissues intrinsically communicate with each other, with focus on the potential effect of exercise in the modulation of this intercommunication.