A Comparison of Bone-Targeted Exercise Strategies to Reduce Fracture Risk in Middle-Aged and Older Men with Osteopenia and Osteoporosis: LIFTMOR-M Semi-Randomized Controlled Trial

Effects of kinect-based virtual reality training on bone mineral density and fracture risk in postmenopausal women with osteopenia: a randomized controlled trial

Osteopenia is a condition characterized by low bone mineral density (BMD) that increases fracture risk, particularly among postmenopausal women (PMW). This study aimed to determine the effects of Kinect-based VRT on BMD and fracture risk in PMW with osteopenia. The study was a prospective, two-arm, parallel-design, randomized controlled trial. The study enrolled 52 participants, 26 randomly assigned to each group. In the experimental group, Kinect-based VRT was provided thrice weekly for 24 weeks for 45 min/session. Both groups were instructed to engage in a daily 30-min walk outdoors. The fracture risk assessment tool (FRAX) was used to calculate fracture risk, and dual-energy X-ray absorptiometry was used to measure lumbar spine and femur neck BMD. Both variables were assessed at baseline and 24 weeks afterwards. After 24 weeks of Kinect-based VRT, the experimental group showed significant BMD increases in the right and left femoral necks and lumbar spine (p value < 0.001). In the control group, the BMD at the right and left femoral necks showed fewer significant changes (p value < 0.022 and 0.004, respectively). In the control group, lumbar spine BMD did not change (p = 0.57). The experimental group showed significantly lower FRAX scores for hip fracture prediction (HFP) and hip prediction of major osteoporotic (HPMO) at both femoral necks (p value < 0.001) than the control group (p = 0.05 and p = 0.01, respectively), but no significant change at the left femoral neck for HFP (p = 0.66) or HPMO (p = 0.26). These findings indicate that a Kinect-based VRT intervention resulted in significantly increased BMD and a reduced fracture risk, as predicted by HFP and HPMO measurements. These improvements were more pronounced in the experimental group than in the control group. Thus, Kinect-based VRT may be utilized as an effective intervention to improve BMD and reduce fracture risk in postmenopausal women with osteopenia.

The multi-faceted nature of age-associated osteoporosis

Age-associated osteoporosis (AAOP) poses a significant health burden, characterized by increased fracture risk due to declining bone mass and strength. Effective prevention and early treatment strategies are crucial to mitigate the disease burden and the associated healthcare costs. Current therapeutic approaches effectively target the individual contributing factors to AAOP. Nonetheless, the management of AAOP is complicated by the multitude of variables that affect its development. Main intrinsic and extrinsic factors contributing to AAOP risk are reviewed here, including mechanical unloading, nutrient deficiency, hormonal disbalance, disrupted metabolism, cognitive decline, inflammation and circadian disruption. Furthermore, it is discussed how these can be targeted for prevention and treatment. Although valuable as individual targets for intervention, the interconnectedness of these risk factors result in a unique etiology for every patient. Acknowledgement of the multifaceted nature of AAOP will enable the development of more effective and sustainable management strategies, based on a holistic, patient-centered approach.

Effects of exercise on bone mineral density in middle-aged and older men: A comprehensive meta-analysis

This meta-analysis including 10 randomised controlled trials suggests that exercise is associated with a statistically significant, but relatively mild, improvement effect on bone mineral density in middle-aged and older men, indicating that exercise has the potential to be a safe and effective way toavert bone loss in men.

PURPOSE

To determine the effect of exercise on bone mineral density (BMD) in middle-aged and older men.

METHODS

We searched three electronic databases up to March 21, 2022. A systematic review of the literature according to the PRISMA statement included (1) randomised controlled trials (RCTs), with (2) at least one exercise group as an intervention versus a control group, (3) men aged ≥ 45 years old, and (4) areal BMD of the lumbar spine (LS) and/or femoral neck (FN) and/or total hip (TH) and/or trochanter region. Mean differences (MD) for BMD changes at the LS, FN, TH, and trochanter were defined as outcome measures.

RESULTS

A total of 10 eligible RCTs were included (N = 555 participants). Exercise significantly improved BMD, and the summarised MD was 0.02 (95% CI: 0.00 to 0.05) for LS BMD, 0.01 (95% CI: 0.00 to 0.02) for FN BMD, 0.01 (95% CI: 0.00 to 0.01) for TH BMD, and 0.03 (95% CI: 0.00 to 0.05) for trochanter BMD. Subgoup analyses showed the improvement effect was statistically significant in trials with longer duration and higher intensity in LS (≥ 12 months: MD, 0.01, 95% CI:0.00 to 0.03; higher intensity: MD, 0.01, 95% CI:0.00 to 0.03) and FN (≥ 12 months: MD, 0.02, 95% CI:0.01 to 0.02; higher intensity: MD, 0.01, 95% CI:0.01 to 0.02).

CONCLUSION

Our results suggested a relatively mild, improvement effect of exercise on LS and proximal femur BMD. Exercise has the potential to be an effective way to avert bone loss in middle-aged and older men.

Is There a Causal Relationship between Physical Activity and Bone Microarchitecture? A Study of Adult Female Twin Pairs

The reasons for the association between physical activity (PA) and bone microarchitecture traits are unclear. We examined whether these associations were consistent with causation and/or with shared familial factors using a cross-sectional study of 47 dizygotic and 93 monozygotic female twin pairs aged 31-77 years. Images of the nondominant distal tibia were obtained using high-resolutionperipheral quantitative computed tomography. The bone microarchitecture was assessed using StrAx1.0 software. Based on a self-completed questionnaire, a PA index was calculated as a weighted sum of weekly hours of light (walking, light gardening), moderate (social tennis, golf, hiking), and vigorous activity (competitive active sports) = light + 2 * moderate + 3 * vigorous. We applied Inference about Causation through Examination of FAmiliaL CONfounding (ICE FALCON) to test whether cross-pair cross-trait associations changed after adjustment for within-individual associations. Within-individual distal tibia cortical cross-sectional area (CSA) and cortical thickness were positively associated with PA (regression coefficients [β] = 0.20 and 0.22), while the porosity of the inner transitional zone was negatively associated with PA (β = -0.17), all p < 0.05. Trabecular volumetric bone mineral density (vBMD) and trabecular thickness were positively associated with PA (β = 0.13 and 0.14), and medullary CSA was negatively associated with PA (β = -0.22), all p ≤ 0.01. Cross-pair cross-trait associations of cortical thickness, cortical CSA, and medullary CSA with PA attenuated after adjustment for the within-individual association (p = 0.048, p = 0.062, and p = 0.028 for changes). In conclusion, increasing PA was associated with thicker cortices, larger cortical area, lower porosity of the inner transitional zone, thicker trabeculae, and smaller medullary cavities. The attenuation of cross-pair cross-trait associations after accounting for the within-individual associations was consistent with PA having a causal effect on the improved cortical and trabecular microarchitecture of adult females, in addition to shared familial factors. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Exercise improves subchondral bone microenvironment through regulating bone-cartilage crosstalk

Articular cartilage degeneration has been proved to cause a variety of joint diseases, among which osteoarthritis is the most typical. Osteoarthritis is characterized by articular cartilage degeneration and persistent pain, which affects the quality of life of patients as well as brings a heavy burden to society. The occurrence and development of osteoarthritis is related to the disorder of the subchondral bone microenvironment. Appropriate exercise can improve the subchondral bone microenvironment, thus playing an essential role in preventing and treating osteoarthritis. However, the exact mechanism whereby exercise improves the subchondral bone microenvironment remains unclear. There is biomechanical interaction as well as biochemical crosstalk between bone and cartilage. And the crosstalk between bone and cartilage is the key to bone-cartilage homeostasis maintenance. From the perspective of biomechanical and biochemical crosstalk between bone and cartilage, this paper reviews the effects of exercise-mediated bone-cartilage crosstalk on the subchondral bone microenvironment, aiming to provide a theoretical basis for the prevention and treatment of degenerative bone diseases.

Exercise to Prevent and Manage Frailty and Fragility Fractures

PURPOSE OF REVIEW

This review identifies exercise-based recommendations to prevent and manage frailty and fragility fractures from current clinical practice guidelines. We also critically assess recently published literature in relation to exercise interventions to mitigate frailty and fragility fractures.

RECENT FINDINGS

Most guidelines presented similar recommendations that included the prescription of individually tailored, multicomponent exercise programs, discouragement of prolonged sitting and inactivity, and combining exercise with optimal nutrition. To target frailty, guidelines recommend supervised progressive resistance training (PRT). For osteoporosis and fragility fractures, exercise should include weight-bearing impact activities and PRT to target bone mineral density (BMD) at the hip and spine, and also incorporate balance and mobility training, posture exercises, and functional exercise relevant to activities of daily living to reduce falls risk. Walking as a singular intervention has limited benefits for frailty and fragility fracture prevention and management. Current evidence-based clinical practice guidelines for frailty, osteoporosis, and fracture prevention recommend a multifaceted and targeted approach to optimise muscle mass, strength, power, and functional mobility as well as BMD.

Low-intensity resistance training to improve knee extension strength in community-dwelling older adults: Systematic review and meta-analysis of randomized controlled studies

AIM

The purpose of this systematic review and meta-analysis was to investigate the effects of low-intensity resistance training on knee extension strength with respect to intensity, frequency, duration and training site in community-dwelling older adults.

METHODS

A literature search was conducted for articles published up to December 2018 on PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Physiotherapy Evidence Database (PEDro), OTseeker and Ichushi-Web. Randomized controlled trials involving resistance training with <60 % one repetition maximum (1RM) in community-dwelling older adults aged 60 years and older were eligible.

RESULTS

In total, 7 studies involving 275 participants were included in the meta-analysis. The results showed significant improvements in knee extension strength with low-intensity resistance training [standardized mean difference (SMD) 0.62, 95 % confidence interval (CI) 0.32 to 0.91]. In subgroup analyses, significant improvements were observed in the group with intensity at 50-60 % 1RM (0.83, 0.46 to 1.19), but not in the group at 40 % or less 1RM (0.30, 95%CI: -0.08 to 0.68). Concerning frequency, there were significant improvements in knee strength for those receiving training three times (0.90, 0.52 to 1.27) and two times (0.36, 0.03 to 0.69) per week, with a significant difference between the groups (p = 0.04).

CONCLUSIONS

Low-intensity resistance training should be considered as an effective intervention to improve knee extension strength in community-dwelling older adults. Older adults may show more improvement in knee extension strength if intensity of the training is set at 50-60 % 1RM and frequency of training is three times per week.

Geometry and bone mineral density determinants of femoral neck strength changes following exercise

Physical exercise induces spatially heterogeneous adaptation in bone. However, it remains unclear where the changes in BMD and geometry have the greatest impact on femoral neck strength. The aim of this study was to determine the principal BMD-and-geometry changes induced by exercise that have the greatest effect on femoral neck strength. Pre- and post-exercise 3D-DXA images of the proximal femur were collected of male participants from the LIFTMOR-M exercise intervention trial. Meshes with element-by-element correspondence were generated by morphing a template mesh to each bone to calculate changes in BMD and geometry. Finite element (FE) models predicted femoral neck strength changes under single-leg stance and sideways fall load. Partial least squares regression (PLSR) models were developed with BMD-only, geometry-only, and BMD-and-geometry changes to determine the principal modes that explained the greatest variation in neck strength changes. The PLSR models explained over 90% of the strength variation with 3 PLS components using BMD-only (R² > 0.92, RMSE < 0.06 N) and 8 PLS components with geometry-only (R² > 0.93, RMSE < 0.06 N). Changes in the superior neck and distal cortex were most important during single-leg stance while the superior neck, medial head, and lateral trochanter were most important during a sideways fall. Local changes in femoral neck and head geometry could differentiate the exercise groups from the control group. Exercise interventions may target BMD changes in the superior neck, inferior neck, and greater trochanter for improved femoral neck strength in single-leg stance and sideways fall.

Bone health in ageing men

Osteoporosis does not only affect postmenopausal women, but also ageing men. The burden of disease is projected to increase with higher life expectancy both in females and males. Importantly, osteoporotic men remain more often undiagnosed and untreated compared to women. Sex steroid deficiency is associated with bone loss and increased fracture risk, and circulating sex steroid levels have been shown to be associated both with bone mineral density and fracture risk in elderly men. However, in contrast to postmenopausal osteoporosis, the contribution of relatively small decrease of circulating sex steroid concentrations in the ageing male to the development of osteoporosis and related fractures, is probably only minor. In this review we provide several clinical and preclinical arguments in favor of a 'bone threshold' for occurrence of hypogonadal osteoporosis, corresponding to a grade of sex steroid deficiency that in general will not occur in many elderly men. Testosterone replacement therapy has been shown to increase bone mineral density in men, however data in osteoporotic ageing males are scarce, and evidence on fracture risk reduction is lacking. We conclude that testosterone replacement therapy should not be used as a sole bone-specific treatment in osteoporotic elderly men.

Higher bone remodeling biomarkers are related to a higher muscle function in older adults: Effects of acute exercise

Bone and muscle are closely linked mechanically and biochemically. Bone hormones secreted during bone remodeling might be linked to muscle mass and strength maintenance. Exercise elicits high mechanical strain and is essential for bone health. However, the relationship between commonly used bone turnover markers (BTMs) and muscle function in community dwelling older adults remains unclear. It is also unknown how acute exercise with differing mechanical strain may affect BTMs, and whether baseline muscle function alters BTM responses differently. We tested the hypothesis that BTMs are associated with muscle function, and that acute exercise could change the circulating levels of BTMs. Thirty-five older adults (25 females/10 males, 72.8 ± 6.0 years) participated. Baseline assessments included body composition (DXA), handgrip strength and a physical performance test (PPT) (gait speed, timed-up-and-go [TUG], stair ascent/descent). Leg muscle quality (LMQ) and stair climb power (SCP) were calculated. Participants performed (randomized) 30 min aerobic (AE) (cycling 70%HR_Peak) and resistance (RE) (leg press 70%RM, jumping) exercise. Serum β-isomerized C-terminal telopeptides (β-CTX), procollagen of type I propeptide (P1NP), total osteocalcin (t)OC and ucOC were assessed at baseline and post-exercise. Data were analyzed using linear mixed models and simple regressions, adjusted for sex. At baseline, higher muscle strength (LMQ, handgrip) was related to higher P1NP, higher SCP was related to higher P1NP and β-CTX, and better physical performance (lower PPT) related to higher P1NP and β-CTX (p < 0.05). Exercise, regardless of mode, decreased β-CTX and tOC (all p < 0.05), while P1NP and ucOC remained unaltered. Higher baseline handgrip strength, SCP and LMQ was associated with lower post-exercise β-CTX responses, and poorer baseline mobility (increased TUG time) was associated with higher post-exercise β-CTX. Independently of exercise mode, acute exercise decreased β-CTX and tOC. Our data suggest that in older adults at baseline, increased BTM levels were linked to better muscle function. Altogether, our data strengthens the evidence for bone-muscle interaction, however, mechanisms behind this specific component of bone-muscle crostalk remain unclear.

Comparing the effectiveness of type of the traditional Chinese exercises, frequency, intensity, time in osteoporosis: a protocol for systematic evaluation and network meta-analysis of randomised controlled trials

INTRODUCTION

As populations age, osteoporosis has become a hot topic of global public concern. The beneficial effects of traditional Chinese exercises on the musculoskeletal system have been demonstrated. However, previous research findings on osteoporosis are inconsistent, and it is unclear which type of exercise and its frequency and duration have the best effect on osteoporosis. This study aims to investigate the most appropriate exercise modality for people with osteoporosis through systematic evaluation and network meta-analysis to guide clinical practice.

METHODS AND ANALYSIS

The Cochrane Library, Web of Science, MEDLINE, Embase, China Biomedical Literature, China Knowledge Network, China Science and Technology Journal and Wanfang databases will be searched until January 2022. The language of the articles should be English or Chinese. All clinical randomised controlled trials on the effect of traditional Chinese exercises on osteoporosis will be included. We will use RevMan, Stata and GeMTC software to complete our network meta-analysis. We will perform risk of bias assessment, subgroup analysis and sensitivity analysis to correct the results. Finally, we will use the Grading of Recommendations Assessment, Development and Evaluation guideline development tool and Confidence in Network Meta-Analysis (CINeMA, a new method for assessing CINeMA results) approach to evaluate the reliability of our final results.

ETHICS AND DISSEMINATION

All data for this study will be obtained from published studies, so no ethical review will be needed. We will publish the results of the study in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42022323622.

A comparison of different exercise intensities for improving bone mineral density in postmenopausal women with osteoporosis: A systematic review and meta-analysis

Objective

This study aimed to compare the effects of moderate- and high-intensity resistance and impact training (MiRIT and HiRIT, respectively) on changes in bone mineral density (BMD) in postmenopausal women with osteoporosis.

Methods

Randomized controlled trials that compared the intervention effects of MiRIT and HiRIT were used as selection criteria to assess study patients with osteoporosis or an osteoporotic condition. Database searches were conducted on August 25, 2022, using CENTRAL, PubMed, CINAHL Web of Science, EMBASE, and MEDLINE. A risk of bias assessment was performed using Revised Cochrane risk of bias tool for the assessment of randomized controlled trials. Point estimates and 95 % confidence intervals of change in BMD derived using dual-energy X-ray absorptiometry were collected as outcomes, and a meta-analysis was performed using the amount of change in BMD before and after the intervention. Adverse event data were also collected.

Results

The search yielded six studies (391 patients, mean age 53–65 years) that met the inclusion criteria. The intervention duration ranged from 24 weeks to 13 months. Compared with the MiRIT group, the HiRIT group showed significantly improved BMD of the lumbar spine (standardized mean difference 2.37 [0.10–4.65]). However, a high degree of heterogeneity was observed for three studies (154 patients, I² = 98 %). Almost all studies reported minimal adverse events. The certainty of evidence was extremely low because of the risk of bias, inconsistency among studies, and imprecision in terms of sample size.

Conclusion

Postmenopausal women with osteoporosis may achieve more significantly improved lumbar spine BMD with HiRIT than with MiRIT.

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The effects of moderate versus high-intensity training on bone mineral density in postmenopausal woman were compared.

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High-intensity training would be more beneficial for improving bone mineral density of the lumbar spine than moderate one.

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Almost all studies reported minimal adverse events.

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However, the lack of certainty associated with the evidence should be considered for clinical application.

Exercise for osteoporosis: A literature review of pathology and mechanism

Osteoporosis (OP) is a disease that weakens bones and has a high morbidity rate worldwide, which is prevalent among the elderly, particularly, women of postmenopausal age. The dynamic balance between bone formation and resorption is necessary for normal bone metabolism. Many factors, including aging, estrogen deficiency, and prolonged immobilization, disrupt normal apoptosis, autophagy, and inflammation, leading to abnormal activation of osteoclasts, which gradually overwhelm bone formation by bone resorption. Moderate exercise as an effective non-drug treatment helps increase bone formation and helps relieve OP. The possible mechanisms are that exercise affects apoptosis and autophagy through the release of exercise-stimulated myohormone and the secretion of anti-inflammatory cytokines via mechanical force. In addition, exercise may also have an impact on the epigenetic processes involved in bone metabolism. Mechanical stimulation promotes bone marrow mesenchymal stem cells (BMSCs) to osteogenic differentiation by altering the expression of non-coding RNAs. Besides, by reducing DNA methylation, the mechanical stimulus can also alter the epigenetic status of osteogenic genes and show associated increased expression. In this review, we reviewed the possible pathological mechanisms of OP and summarized the effects of exercise on bone metabolism, and the mechanisms by which exercise alleviates the progression of OP, to provide a reference for the prevention and treatment of OP.

Homo sapiens May Incorporate Daily Acute Cycles of “Conditioning–Deconditioning” to Maintain Musculoskeletal Integrity: Need to Integrate with Biological Clocks and Circadian Rhythm Mediators

Human evolution required adaptation to the boundary conditions of Earth, including 1 g gravity. The bipedal mobility of Homo sapiens in that gravitational field causes ground reaction force (GRF) loading of their lower extremities, influencing the integrity of the tissues of those extremities. However, humans usually experience such loading during the day and then a period of relative unloading at night. Many studies have indicated that loading of tissues and cells of the musculoskeletal (MSK) system can inhibit their responses to biological mediators such as cytokines and growth factors. Such findings raise the possibility that humans use such cycles of acute conditioning and deconditioning of the cells and tissues of the MSK system to elaborate critical mediators and responsiveness in parallel with these cycles, particularly involving GRF loading. However, humans also experience circadian rhythms with the levels of a number of mediators influenced by day/night cycles, as well as various levels of biological clocks. Thus, if responsiveness to MSK-generated mediators also occurs during the unloaded part of the daily cycle, that response must be integrated with circadian variations as well. Furthermore, it is also possible that responsiveness to circadian rhythm mediators may be regulated by MSK tissue loading. This review will examine evidence for the above scenario and postulate how interactions could be both regulated and studied, and how extension of the acute cycles biased towards deconditioning could lead to loss of tissue integrity.

Exercise Prescription for Osteoporosis: Back to Basics

This Perspectives provides a back-to-basics rationale for the ideal exercise prescription for osteoporosis. The relevance of fundamental principles of mechanical loading and bone adaptation determined from early animal studies is revisited. The application to human trials is presented, including recent advances. A model of broadscale implementation is described, and areas for further investigation are identified.

Exercise to Mend Aged-tissue Crosstalk in Bone Targeting Osteoporosis & Osteoarthritis

Aging induces alterations in bone structure and strength through a multitude of processes, exacerbating common aging- related diseases like osteoporosis and osteoarthritis. Cellular hallmarks of aging are examined, as related to bone and the marrow microenvironment, and ways in which these might contribute to a variety of age-related perturbations in osteoblasts, osteocytes, marrow adipocytes, chondrocytes, osteoclasts, and their respective progenitors. Cellular senescence, stem cell exhaustion, mitochondrial dysfunction, epigenetic and intracellular communication changes are central pathways and recognized as associated and potentially causal in aging. We focus on these in musculoskeletal system and highlight knowledge gaps in the literature regarding cellular and tissue crosstalk in bone, cartilage, and the bone marrow niche. While senolytics have been utilized to target aging pathways, here we propose non-pharmacologic, exercise-based interventions as prospective "senolytics" against aging effects on the skeleton. Increased bone mass and delayed onset or progression of osteoporosis and osteoarthritis are some of the recognized benefits of regular exercise across the lifespan. Further investigation is needed to delineate how cellular indicators of aging manifest in bone and the marrow niche and how altered cellular and tissue crosstalk impact disease progression, as well as consideration of exercise as a therapeutic modality, as a means to enhance discovery of bone-targeted therapies.

The effect of low-intensity whole-body vibration with or without high-intensity resistance and impact training on risk factors for proximal femur fragility fracture in postmenopausal women with low bone mass: study protocol for the VIBMOR randomized controlled trial

BACKGROUND

The prevailing medical opinion is that medication is the primary (some might argue, only) effective intervention for osteoporosis. It is nevertheless recognized that osteoporosis medications are not universally effective, tolerated, or acceptable to patients. Mechanical loading, such as vibration and exercise, can also be osteogenic but the degree, relative efficacy, and combined effect is unknown. The purpose of the VIBMOR trial is to determine the efficacy of low-intensity whole-body vibration (LIV), bone-targeted, high-intensity resistance and impact training (HiRIT), or the combination of LIV and HiRIT on risk factors for hip fracture in postmenopausal women with osteopenia and osteoporosis.

METHODS

Postmenopausal women with low areal bone mineral density (aBMD) at the proximal femur and/or lumbar spine, with or without a history of fragility fracture, and either on or off osteoporosis medications will be recruited. Eligible participants will be randomly allocated to one of four trial arms for 9 months: LIV, HiRIT, LIV + HiRIT, or control (low-intensity, home-based exercise). Allocation will be block-randomized, stratified by use of osteoporosis medications. Testing will be performed at three time points: baseline (T0), post-intervention (T1; 9 months), and 1 year thereafter (T2; 21 months) to examine detraining effects. The primary outcome measure will be total hip aBMD determined by dual-energy X-ray absorptiometry (DXA). Secondary outcomes will include aBMD at other regions, anthropometrics, and other indices of bone strength, body composition, physical function, kyphosis, muscle strength and power, balance, falls, and intervention compliance. Exploratory outcomes include bone turnover markers, pelvic floor health, quality of life, physical activity enjoyment, adverse events, and fracture. An economic evaluation will also be conducted.

DISCUSSION

No previous studies have compared the effect of LIV alone or in combination with bone-targeted HiRIT (with or without osteoporosis medications) on risk factors for hip fracture in postmenopausal women with low bone mass. Should either, both, or combined mechanical interventions be safe and efficacious, alternative therapeutic avenues will be available to individuals at elevated risk of fragility fracture who are unresponsive to or unwilling or unable to take osteoporosis medications.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (www. anzctr.org.au ) (Trial number ANZCTR12615000848505, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id = 368962 ); date of registration 14/08/2015 (prospectively registered). Universal Trial Number: U1111-1172-3652.

Aging, Osteo-Sarcopenia, and Musculoskeletal Mechano-Transduction

The decline in the mass and function of bone and muscle is an inevitable consequence of healthy aging with early onset and accelerated decline in those with chronic disease. Termed osteo-sarcopenia, this condition predisposes the decreased activity, falls, low-energy fractures, and increased risk of co-morbid disease that leads to musculoskeletal frailty. The biology of osteo-sarcopenia is most understood in the context of systemic neuro-endocrine and immune/inflammatory alterations that drive inflammation, oxidative stress, reduced autophagy, and cellular senescence in the bone and muscle. Here we integrate these concepts to our growing understanding of how bone and muscle senses, responds and adapts to mechanical load. We propose that age-related alterations in cytoskeletal mechanics alter load-sensing and mechano-transduction in bone osteocytes and muscle fibers which underscores osteo-sarcopenia. Lastly, we examine the evidence for exercise as an effective countermeasure to osteo-sarcopenia.

Exercise Effects on Bone Mineral Density in Men

In contrast to postmenopausal women, evidence for a favorable effect of exercise on Bone Mineral Density (BMD) is still limited for men. This might be due to the paucity of studies, but also to the great variety of participants and study characteristics that may dilute study results. The aim of the present systematic review and meta-analysis was to evaluate the effect of exercise on BMD changes with rational eligibility criteria. A comprehensive search of six electronic databases up to 15 March 2021 was conducted. Briefly, controlled trials ≥6 months that determined changes in areal BMD in men >18 years old, with no apparent diseases or pharmacological therapy that relevantly affect bone metabolism, were included. BMD changes (standardized mean differences: SMD) of the lumbar spine (LS) and femoral neck (FN) were considered as outcomes. Twelve studies with 16 exercise and 12 control groups were identified. The pooled estimate of random-effect analysis was SMD = 0.38, 95%-CI: 0.14–0.61 and SMD = 0.25, 95%-CI: 0.00–0.49, for LS and FN, respectively. Heterogeneity between the trials was low–moderate. Funnel plots and rank and regression correlation tests indicate evidence for small study publication bias for LS but not FN-BMD. Subgroup analyses that focus on study length, type of exercise and methodologic quality revealed no significant difference between each of the three categories. In summary, we provided further evidence for a low but significant effect of exercise on BMD in men. However, we are currently unable to give even rough exercise recommendations for male cohorts.

Impact of high-load resistance training on bone mineral density in osteoporosis and osteopenia: a meta-analysis

INTRODUCTION

This study aimed to examine the effect of high-load resistance training (HLRT) on bone mineral density (BMD) in patients with osteoporosis and osteopenia using a meta-analysis.

MATERIALS AND METHODS

We searched for randomized controlled trials (RCTs) on HLRT in patients with osteoporosis and osteopenia from medical databases. Our meta-analysis was performed with the primary endpoints being the standardized mean difference (SMD) of the change in BMD of the lumbar spine (LS), femoral neck (FN), and total hip (TH). The robustness of the results was assessed by subgroup analysis. Heterogeneity factors were examined by meta-regression. Publication bias was evaluated using a funnel plot.

RESULTS

We selected nine RCTs, with 259 patients in the HLRT group (women, 55.2%) and 236 patients in the control group (women, 62.7%). The HLRT group showed a significant increase in BMD in the LS [SMD = 1.40, 95% confidence interval (CI) = 0.68-2.12, p < 0.001, I² = 90%], the FN (SMD = 0.86, 95% CI = 0.05-1.67, p = 0.04, I² = 92%), and the TH (SMD = 1.26, 95% CI = 0.45-2.08, p = 0.002, I² = 91%). Subgroup analysis confirmed the robustness of the results only in LS. Total sessions and a high risk of bias were identified as the factors of heterogeneity in FN and TH (p < 0.05). The funnel plot showed asymmetry in all measurement sites.

CONCLUSION

This study suggested that HLRT can be effective in increasing BMD, mainly of LS, in patients with osteoporosis and osteopenia. However, due to high heterogeneity and publication bias, additional studies with a low risk of bias should be conducted to generalize our findings.

A Comparison of Bone-Targeted Exercise With and Without Antiresorptive Bone Medication to Reduce Indices of Fracture Risk in Postmenopausal Women With Low Bone Mass: The MEDEX-OP Randomized Controlled Trial

The goal of the MEDEX-OP trial was to compare the efficacy of a known effective high-intensity resistance and impact training (HiRIT) with a low-intensity exercise control (Buff Bones® [BB]), alone or in combination with antiresorptive bone medication, on indices of fracture risk (bone mass, body composition, muscle strength, functional performance), compliance, and safety. Primary study outcomes were 8-month change in lumbar spine (LS) and total hip (TH) bone mineral density (BMD). Healthy postmenopausal women with low bone mass (T-score ≤ -1.0) on or off stable doses (≥12 months) of antiresorptive medication were recruited. A total of 115 women (aged 63.6 ± 0.7 years; body mass index [BMI] 25.5 kg/m² ; femoral neck [FN] T-score -1.8 ± 0.1) were randomly allocated to 8-month, twice-weekly, 40-minute HiRIT (5 sets of 5 repetitions, >80% to 85% 1 repetition maximum) or BB (low-intensity, Pilates-based training), stratified by medication intake, resulting in four groups: HiRIT (n = 42), BB (n = 44), HiRIT-med (n = 15), BB-med (n = 14). HiRIT improved LS BMD (1.9 ± 0.3% versus 0.1 ± 0.4%, p < 0.001) and stature (0.2 ± 0.1 cm versus -0.0 ± 0.1 cm, p = 0.004) more than BB. Both programs improved functional performance, but HiRIT effects were larger for leg and back muscle strength and the five times sit-to-stand test (p < 0.05). There was a positive relationship between maximum weight lifted and changes in LS BMD and muscle strength in the HiRIT groups. Exploratory analyses suggest antiresorptive medication may enhance exercise efficacy at the proximal femur and lumbar spine. Exercise compliance was good (82.4 ± 1.3%) and both programs were well tolerated (7 adverse events: HiRIT 4; BB 3). HiRIT improved indices of fracture risk significantly more than Buff Bones®. More trials combining bone medication and bone-targeted exercise are needed. © 2021 American Society for Bone and Mineral Research (ASBMR).

Effects of exercise frequency and training volume on bone changes following a multi-component exercise intervention in middle aged and older men: Secondary analysis of an 18-month randomized controlled trial

Progressive resistance training (PRT) combined with weight-bearing impact exercise are recommended to optimize bone health, but the optimal frequency and dose of training remains uncertain. This study, which is a secondary analysis of an 18-month intervention in men aged 50-79 years, examined the association between exercise frequency and the volume of training with changes in DXA and QCT-derived femoral neck (FN) and lumbar spine (LS) bone outcomes, respectively. Men were allocated to either thrice-weekly PRT plus impact exercise training (n = 87) or a non-exercising (n = 85) group. Average weekly exercise frequency (ExFreq) and training volume per session [PRT volume (weight lifted, kg), number of weight-bearing impacts (jumps completed) and total training volume] over the 18-months were calculated from the participants' exercise cards. Regression analysis showed that average weekly ExFreq and training volume per session were positively associated with the 18-month changes in FN BMD and LS trabecular volumetric BMD. Men completing on average 1 to <2 and ≥2 sessions/week had a 1.6 to 2.2% greater net gain in FN BMD relative to non-exercising men, while those completing ≥2 sessions/week had 3.9 to 5.2% net gain in LS trabecular vBMD compared to non-exercising men and those completing <1 session/week. Further analysis showed that the average number of impact loads per session, but not the average PRT weight-lifted, was positively associated with changes in BMD. Every 10 impact loads per session over 18 months was associated with a 0.3% and 1.3% increase in FN BMD and LS trabecular vBMD, respectively. In conclusion, this study indicates that exercise frequency and training volume were predictors of the changes in hip and spine BMD following a multi-component exercise program, and that the number of impact loads rather than PRT weight lifted per session was more important for eliciting positive skeletal responses in middle-aged and older men.

A Case Study of an 87-Year-Old Male Bodybuilder with Complex Health Conditions

This exploratory clinical case report presents an 87-year-old man who began bodybuilding at the age of 76 years and was officially recognised as the world’s oldest competitive bodybuilder, competing until age 83. He has a background of complex health conditions including polio, strokes, cardiac arrest, atrial fibrillation, prostate disease, osteoarthritis, depression, bowel obstruction, reflux, and bladder cancer. Assessments of body composition, bone density, muscle performance, and diet-related practices were performed. The bodybuilder had superior fat-free mass, lower fat mass, and generally greater muscle performance compared to untrained healthy males of a similar age. Commencement of bodybuilding in older age appears to be possible, even with ongoing complex health conditions, and the potential benefits of this practice require systematic investigation in the future.

Exploring thoracic kyphosis and incident fracture from vertebral morphology with high-intensity exercise in middle-aged and older men with osteopenia and osteoporosis: a secondary analysis of the LIFTMOR-M trial

Our aim was to explore change in kyphosis and vertebral fracture incidence following 8 months of high-intensity resistance and impact training (HiRIT) or machine-based isometric axial compression (IAC) training in men with osteopenia and osteoporosis. HiRIT and IAC improved posture. HiRIT participants did not experience progression or incident vertebral fracture. IAC participants did experience progression and incident vertebral fracture.

INTRODUCTION

The Lifting Intervention For Training Muscle and Osteoporosis Rehabilitation for Men (LIFTMOR-M) trial examined efficacy and safety of an eight-month, supervised, high-intensity progressive resistance and impact training (HiRIT) program compared with machine-based isometric axial compression (IAC) training in middle-aged and older men with low areal bone mineral density (aBMD). The primary purpose of the current work was to explore change in thoracic kyphosis and incident fracture from vertebral morphology following eight-months of HiRIT or IAC training. The secondary purpose was to explore change in clinical kyphosis measures for HiRIT, IAC and a non-randomized, matched control group.

METHODS

Men (≥ 45 yrs), with low aBMD, were recruited and randomized to HiRIT or IAC, or designated control. Clinical measures of thoracic kyphosis with inclinometry were determined. Cobb angle of kyphosis and vertebral fracture assessment using the Genant semi-quantitative method were determined from lateral thoracolumbar DXA (Medix DR, Medilink, France). Per-protocol (n = 40) and intention-to-treat (n = 93) analyses were conducted.

RESULTS

Forty participants (HiRIT n = 20, IAC n = 20; 66.1 ± 7.8 yrs.; lumbar spine T-score - 0.1 ± 0.8; femoral neck T-score - 1.5 ± 0.5) underwent clinical kyphosis measures and thoracolumbar DXA at baseline and follow-up. No between-group differences were detected in kyphosis change, however, within-group improvements in neutral (HiRIT - 2.3 ± 0.8°; IAC - 2.5 ± 0.8°) and 'standing tall' (HiRIT - 2.4 ± 0.8°; IAC - 2.0 ± 0.8°) postures were observed (p < 0.05). HiRIT improved Cobb angle (- 3.5 ± 1.5°, p = 0.027) from baseline. Over the 8 months, no incident vertebral fractures nor progression of prevalent vertebral fractures occurred for HiRIT participants. Five incident fractures of thoracic vertebrae occurred for IAC and one wedge fracture progressed. Ninety-three participants underwent clinical kyphosis measures at both time-points (HiRIT n = 34, IAC n = 33, control n = 26). HiRIT exhibited a reduction in 'standing tall' kyphosis compared to control (- 2.3 ± 0.6° versus 1.4 ± 0.7°, p < 0.05), but no other between-group differences were detected.

CONCLUSIONS

Although there was no difference in change between intervention groups, thoracic kyphosis appeared to improve in both HiRIT and IAC with exercise exposure. HiRIT improved 'standing tall' posture in comparison to usual activities. HiRIT was not associated with vertebral fracture progression or incident vertebral fracture, but for some IAC participants there was evidence of progression of vertebral fracture severity and incident vertebral fractures, in our small sample. Larger trials are required to confirm the observations of the current work, which was exploratory in nature.

Physical Activity and Bone Health in Men: A Systematic Review and Meta-Analysis

Background

Research on osteoporosis and physical activity often focuses on women. We aimed to conduct a systematic review to assess the benefits and harms of physical activity interventions for men’s bone health.

Methods

We used standard methods and searched for randomized controlled trials (RCTs) (duration, ≥6 months) published in all languages across multiple databases and trial registries. The last search was conducted on July 22, 2020.

Results

We included 11 studies (14 publications), resulting in a sample of N=723 men (range, 17–132 participants). We found low-certainty evidence that physical activity has little influence on the areal bone mineral density (aBMD) at the total hip (5 RCTs, N=324; mean difference [MD], 0.03 [95 confidence interval (CI), 0.01 to 0.05]) and little or no influence on the aBMD at the femoral neck (3 RCTs, N=186; MD, 0.00 [95% CI, −0.04 to 0.04]), lumbar spine (3 RCTs; N=213; MD, 0.05 [95% CI, −0.01 to 0.11]), and whole body (4 RCTs, N=203; MD, −0.00 [95% CI, −0.03 to 0.02]).

Conclusions

We found low-certainty evidence that physical activity (≥6 months) has some effect on the total hip in men, but new evidence may change this finding. This review highlights the gap in the evidence on specific intervention prescriptions that can benefit the bone geometry, structure, microarchitecture, and, ultimately, bone strength in men. Future research should engage in comprehensive reporting of harms, quality of life outcomes, advanced imaging findings, and long-term interventions.

Assessment of femoral neck strength and bone mineral density changes following exercise using 3D-DXA images

Physical exercise induces spatially heterogeneous bone changes in the proximal femur. Recent advances have enabled 3D dual-energy X-ray Absorptiometry (DXA)-based finite element (FE) models to estimate bone strength. However, its ability to detect exercise-induced BMD and strength changes is unclear. The aim of this study was to quantify the repeatability of vBMD and femoral neck strength obtained from 3D-DXA images and determine the changes due an exercise intervention. The DXA scans included pairs of same-day repeated scans from ten healthy females and pre- and post-exercise intervention scans of 26 males. FE models with element-by-element correspondence were generated by morphing a template mesh to each bone. BMD and femoral strength under single-leg-stance and sideways fall loading configurations were obtained for both groups and compared. In the repeated images, the total hip vBMD difference was 0.5 ± 2.5%. Element-by-element BMD differences reached 30 ± 50%. The strength difference in single-leg stance was 2.8 ± 13% and in sideways fall was 4.5% ± 19%. In the exercise group, strength changes were 6 ± 19% under single-leg stance and 1 ± 18% under sideways fall. vBMD parameters were weakly correlated to strength (R² < 0.31). The exercise group had a mean bone accrual exceeding repeatability values in the femoral head and cortical regions. The case with the highest vBMD change (6.4%) caused 18% and -7% strength changes under single-leg stance and sideways fall. 3D-DXA technology can assess the effect of exercise interventions in large cohorts but its validity in individual cases should be interpreted with caution.

Progressive Resistance Training for Improving Health-Related Outcomes in People at Risk of Fracture: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Osteoporosis clinical practice guidelines recommend exercise to prevent fractures, but the efficacy of exercise depends on the exercise types, population studied, or outcomes of interest. The purpose of this systematic review was to assess the effects of progressive resistance training (PRT) on health-related outcomes in people at risk of fracture.

METHODS

Multiple databases were searched in October 2019. Eligible articles were randomized controlled trials of PRT interventions in men and women ≥50 years with low bone mineral density (BMD) or fracture history. Descriptive information and mean difference (MD) and SD were directly extracted for included trials. A total of 53 studies were included.

RESULTS

The effects of PRT on the total number of falls (incidence rate ratio [IRR] = 1.05; 95% CI = 0.91 - 1.21; 7 studies) and on the risk of falling (risk ratio [RR] = 1.23; 95% CI = 1.00 - 1.51; 5 studies) are uncertain. PRT improved performance on the Timed "Up and Go" test (MD = -0.89 seconds; 95% CI = -1.01 to -0.78; 13 studies) and health-related quality of life (standardized MD = 0.32; 95% CI = 0.22-0.42; 20 studies). PRT may increase femoral neck (MD = 0.02 g/cm2; 95% CI = 0.01-0.03; 521 participants, 5 studies) but not lumbar spine BMD (MD = 0.02 g/cm2; 95% CI = -0.01-0.05; 4 studies), whereas the effects on total hip BMD are uncertain (MD = 0.00 g/cm2; 95% CI = 0.00-0.01; 435 participants, 4 studies). PRT reduced pain (standardized MD = -0.26; 95% CI = -0.37 to -0.16; 17 studies). Sensitivity analyses, including PRT-only studies, confirmed these findings.

CONCLUSION

Individuals at risk of fractures should be encouraged to perform PRT, as it may improve femoral neck BMD, health-related quality of life, and physical functioning. PRT also reduced pain; however, whether PRT increases or decreases the risk of falls, the number of people experiencing a fall, or the risk of fall-related injuries is uncertain.

IMPACT

Individuals at risk of fractures should be encouraged to perform PRT, as it may have positive effects on femoral neck BMD, health-related quality of life, physical functioning, and pain, and adverse events are rare.

LAY SUMMARY

Exercise is recommended for people at risk of osteoporotic fractures. Our study showed that progressive resistance training improves physical functioning, quality of life, and reduces pain. The effects of progressive resistance training on the risk of falling are unclear. Adverse events are rare, and often minor (eg, soreness, pain, musculoskeletal injury). Considering the benefits and safety, people at risk of fractures should engage in progressive resistance training interventions.

Non-Pharmacological Interventions in Osteosarcopenia: A Systematic Review

BACKGROUND

Osteosarcopenia is a geriatric syndrome defined by the concomitant presence of osteopenia/osteoporosis (loss of bone mineral density (BMD)) and sarcopenia (loss of muscle mass and/or function), which increases the risk of falls, fractures, and premature mortality.

OBJECTIVE

To examine the efficacy of non-pharmacological (exercise and/or nutritional) interventions on musculoskeletal measures and outcomes in osteosarcopenic adults by reviewing findings from randomized controlled trials (RCTs).

METHODS

This review was registered at PROSPERO (registration number: CRD42020179292) and conducted in accordance with the PRISMA guidelines. Electronic databases were searched for RCTs assessing the effect of at least one non-pharmacological intervention (any form of exercise and/or supplementation with protein, vitamin D, calcium or creatine) on any musculoskeletal measure/outcome of interest (BMD, bone strength/turnover, muscle mass and strength, physical performance, falls/fractures) in adults with osteosarcopenia as defined by any proposed criteria.

RESULTS

Two RCTs (of n=106 older osteosarcopenic adults (≥65 years)) assessing the effects of progressive resistance training (RT) (via resistance bands or machines; 2-3 times/week; ~60 minutes in duration) were eligible for inclusion. The two RCTs demonstrated moderate quality evidence that RT increases muscle mass, strength, and quality, with changes in strength and quality occurring before muscle mass (12 vs 28 weeks). There was low quality evidence that RT increases lumbar spine BMD and maintains total hip BMD when performed for 12 and 18 months, respectively, and moderate quality evidence that RT has no effect on markers of bone turnover or physical performance. No major adverse effects were recorded in either of the RCTs. There were no eligible RCTs examining the impact of nutritional interventions.

CONCLUSION

Chronic RT is safe and effective at potentiating gains in muscle mass, strength, and quality, and increasing or maintaining BMD in older osteosarcopenic adults. No RCT has examined the effects of protein, vitamin D, calcium, or creatine against a control/placebo in this high-risk population.

Exercise and Diet: Uncovering Prospective Mediators of Skeletal Fragility in Bone and Marrow Adipose Tissue

PURPOSE OF REVIEW

To highlight recent basic, translational, and clinical works demonstrating exercise and diet regulation of marrow adipose tissue (MAT) and bone and how this informs current understanding of the relationship between marrow adiposity and musculoskeletal health.

RECENT FINDINGS

Marrow adipocytes accumulate in the bone in the setting of not only hypercaloric intake (calorie excess; e.g., diet-induced obesity) but also with hypocaloric intake (calorie restriction; e.g., anorexia), despite the fact that these states affect bone differently. With hypercaloric intake, bone quantity is largely unaffected, whereas with hypocaloric intake, bone quantity and quality are greatly diminished. Voluntary running exercise in rodents was found to lower MAT and promote bone in eucaloric and hypercaloric states, while degrading bone in hypocaloric states, suggesting differential modulation of MAT and bone, dependent upon whole-body energy status. Energy status alters bone metabolism and bioenergetics via substrate availability or excess, which plays a key role in the response of bone and MAT to mechanical stimuli. Marrow adipose tissue (MAT) is a fat depot with a potential role in-as well as responsivity to-whole-body energy metabolism. Understanding the localized function of this depot in bone cell bioenergetics and substrate storage, principally in the exercised state, will aid to uncover putative therapeutic targets for skeletal fragility.

Effects of supervised high-intensity resistance and impact training or machine-based isometric training on regional bone geometry and strength in middle-aged and older men with low bone mass: The LIFTMOR-M semi-randomised controlled trial

INTRODUCTION

Few data exist on the effects of bone-targeted exercise on geometric and biomechanical indices of bone strength in men. The Lifting Intervention For Training Muscle and Osteoporosis Rehabilitation for Men (LIFTMOR-M) trial was designed to compare the efficacy and safety of two novel, supervised, twice-weekly, high-intensity exercise programs in middle-aged and older men with osteopenia and osteoporosis on musculoskeletal health and risk factors related to falls and fractures. The current report includes secondary outcomes of the LIFTMOR-M exercise intervention trial.

PURPOSE

Our goal was to determine the effects of two supervised, twice-weekly, high-intensity exercise programs on bone geometry and strength of the proximal femur, and distal and proximal sites of the tibia and radius in middle-aged and older men with osteopenia and osteoporosis.

METHODS

Generally-healthy men (≥45 years), with low lumbar spine (LS) and/or proximal femur areal bone mineral density (aBMD), were recruited from the community. Eligible participants were randomised to either eight months of twice-weekly supervised high-intensity progressive resistance and impact training (HiRIT) or supervised machine-based isometric axial compression (IAC) exercise training. Intervention group outcomes were compared at baseline and eight months with a matched but non-randomised control group (CON) who self-selected to usual activities. DXA scans (Medix DR, Medilink, France) of the skeletally non-dominant proximal femur were analysed using 3D hip software (DMS Group, France) to derive femoral neck (FN) and total hip (TH) bone mineral content (BMC), volume, and volumetric bone mineral density (vBMD) for total, trabecular and cortical bone compartments. Total FN cortical thickness was determined as well as anterior, posterior, lateral and medial subregions. pQCT scans (XCT-3000, Stratec, Germany) of the 4 and 38% sites of the tibia, and 4 and 66% sites of the radius were conducted to determine a range of geometric and bone structural strength indices. Intervention effects were examined using univariate ANCOVA of percent change, and repeated measures ANCOVA of raw baseline and follow-up data, controlling for initial values, using intention-to-treat and per-protocol approaches.

RESULTS

Ninety-three men (67.1 ± 7.5 yrs, 175.2 ± 6.7 cm, 82.1 ± 11.6 kg, 26.7 ± 3.5 kg/m²) with lower than average aBMD (LS T-score -0.06 ± 1.04, FN T-score -1.58 ± 0.58, TH T-score -1.00 ± 0.58) were recruited, and designated CON (n = 26) or randomised to HiRIT (n = 34) or IAC (n = 33). Compliance to the supervised exercise programs did not differ (HiRIT 77.8 ± 16.6% versus IAC 78.5 ± 14.8%, p = 0.872). HiRIT improved medial FN cortical thickness compared with CON (5.6 ± 1.7% versus -0.1 ± 1.9%, p = 0.028) and IAC (5.6 ± 1.7% versus 0.7 ± 1.7%, p = 0.044). Distal tibia total BMC, vBMD, area and bone strength index, and trabecular BMC and bone strength index all declined for CON compared with maintenance for both HiRIT and IAC (all p < 0.05). HiRIT maintained distal tibia trabecular area compared with a loss in CON (0.2 ± 0.5% versus -1.6 ± 0.5%, p = 0.013). HiRIT and IAC maintained distal radius total BMC compared with loss in CON (-0.1 ± 0.7% versus -3.7 ± 0.8%, p = 0.001; 1.3 ± 0.7% versus -3.7 ± 0.8%, p < 0.001, respectively). HiRIT and IAC maintained distal radius total bone strength index compared with loss in CON (1.4 ± 1.4% versus -6.0 ± 1.6%, p = 0.001; 0.2 ± 1.3% versus -6.0 ± 1.6%, p = 0.004, respectively). HiRIT reduced proximal radius cortical area compared with CON (-3.1 ± 1.0% versus 1.1 ± 1.2%, p = 0.011) and IAC (-3.1 ± 1.0% versus -0.2 ± 1.0%, p = 0.042). No between-group differences were detected in any pQCT-derived bone outcome at the diaphyseal tibia 38% site.

CONCLUSION

Findings indicate that supervised HiRIT provides a positive stimulus to cortical bone at the medial FN compared with supervised IAC exercise, and both HiRIT and IAC preserve bone strength at the distal tibia and distal radius. These effects may translate into a reduced risk of lower and upper extremity fracture in middle-aged and older men with low bone mass.