The BPAQ: a bone-specific physical activity assessment instrument

The Influence of Adolescent Physical Activity on Bone Mineral Density among Adult Runners

This study aimed to determine the influence of sport type and training volume during adolescence on low bone mineral density (BMD) in long-distance runners. In total, 125 competitive long-distance runners (64 males; 21.3±4.2 years, 61 females; 21.4±3.1 years) participated in this retrospective cohort study. We collected training history data during adolescence using a questionnaire and measured BMD of the lumbar spine and whole body using dual-energy X-ray absorptiometry (DXA). Male runners with low BMD ran for more hours (p=0.02) and had a smaller proportion of multidirectional loading activity (p=0.03) in elementary school than those with normal BMD. Although female runners with low BMD performed multidirectional activity for more hours in middle school than those with normal BMD (p=0.01), running volume was similar between groups. There was an increasing trend in the total number of hours of physical activity in middle school in female runners with low BMD (p=0.05). These results suggest that avoiding specialization in long-distance running, increasing the proportion of multidirectional sports, and preventing overload during the bone growth phase may reduce the risk of low BMD among runners.

Skeletal Loading: Lean and Bone Mass Development in Young Elite Male Gymnasts, Swimmers, and Nonathletes Aged 6-24 Years

BACKGROUND

Exercise optimizes peak bone mass accrual, particularly if the loading is high magnitude and distributed in abnormal directions. Little is known about the influence of early intense training in sport during peak bone mass accrual, especially in boys.

METHODS

Ninety-eight males aged 6-24 years (gymnasts, swimmers, and controls) completed the bone-specific physical activity questionnaire and a 7-day exercise diary. Dual-energy X-ray absorptiometry determined bone mineral properties of the total body (less head) and lumbar spine (LS, L1-L4) and total lean mass. Subgroup analyses were conducted for juniors (prepubescent), adolescents (11-16 y), and seniors (17-24 y).

RESULTS

Lean mass was positively associated with total body less head and LS bone outcomes in all 3 age groups (R2 = .632-.770, P < .05), and bone-specific physical activity questionnaire scores were associated with LS bone mineral density in adolescents and seniors (R2 = .440 and .591, P < .05). Senior gymnasts had significantly higher LS bone mineral density (in grams per square centimeter) and Z-scores than swimmers (P = .004) and controls (P = .012).

CONCLUSIONS

Elite gymnastics is associated with superior peak bone mass accrual in young males. The benefits appear more pronounced during young adulthood compared with prepuberty, potentially reflecting an extended time course for bone adaptation.

Study protocol for the ROLEX-DUO randomised placebo-controlled trial: ROmosozumab Loaded with EXercise - DUal effects on bone and muscle in postmenopausal Osteoporosis and Osteopenia

INTRODUCTION

Novel strategies are needed to address the rising burden of osteoporosis and fragility fractures. High-intensity resistance and impact (HiRIT) exercise has shown benefit in improving bone density in postmenopausal women with osteoporosis/osteopenia. Whether HiRIT can enhance the therapeutic effects of osteoporosis pharmacotherapy has not been established. ROLEX-DUO is a randomised controlled trial designed to assess the efficacy of romosozumab on various bone and muscle outcomes in combination with different exercise interventions in women with postmenopausal osteoporosis/osteopenia.

METHODS AND ANALYSIS

ROLEX-DUO is an 8-month randomised placebo-controlled trial conducted at two tertiary referral centres for patients with osteoporosis/osteopenia in Sydney, New South Wales, Australia. The study is implementing the combination of romosozumab or placebo with different forms of exercise in postmenopausal women with osteoporosis/osteopenia without recent fragility fracture (n=102). Eligible women will be randomised 1:1:1 into one of three groups: (1) romosozumab with supervised HiRIT, (2) romosozumab with unsupervised low-intensity exercise or (3) placebo with unsupervised low-intensity exercise. Co-primary outcomes are the mean percentage change in lumbar spine bone mineral density (BMD), and mean change in five times sit-to-stand test performance (seconds) at 8 months. Secondary/exploratory outcomes include BMD changes at the femoral neck, total hip and distal radius, three-dimensional dual-energy X-ray absorptiometry (DXA) hip outcomes, DXA-derived lean and fat mass, serum markers of bone turnover (procollagen type 1 peptide, C-telopeptide of type 1 collagen) and bone biomarkers (dickkopf-1), serum extracellular vesicle analyses, 36-Item Short Form Survey (SF-36) quality-of-life scores, Menopause-Specific Quality Of Life (MENQOL) Questionnaire menopause symptom burden scores, number of falls and fractures. Mixed-effects models will be performed to compare longitudinal outcome results between groups using intention-to-treat analysis.

ETHICS AND DISSEMINATION

The trial was approved by the Northern Sydney Local Health District Human Research Ethics Committee (2022/ETH01794, protocol V.8, dated 03 July 2024). Participants will provide written informed consent prior to inclusion. Findings will be disseminated via peer-reviewed journals, scientific conferences and summary reports to funding bodies.

TRIAL REGISTRATION NUMBER

ACTRN12623000867695.

Effects of the Type of Exercise Training on Bone Health Parameters in Adolescent Girls: A Systematic Review

Interventional studies offer strong evidence for exercise's osteogenic impact on bone particularly during growth. With rising osteoporosis rates in older women, enhancing bone strength early in life is crucial. Thus, investigating the osteogenic effects of different types of physical activities in young females is crucial. Despite varied findings, only two systematic reviews tried to explore this topic without examining how different types of exercise may affect bone health in adolescent girls. The first aim of this systematic review was to assess the impact of exercise training on bone health parameters in adolescent girls, and the second aim was to investigate whether the type of exercise training can modulate this effect. A systematic literature search was conducted using common electronic databases from inception - January 2023. Seven studies (355 participants) were eligible for inclusion in this systematic review. Two studies dealt with resistance training, 3 studies applied plyometric training, 1 study used team sports, and 1 study used dancing. Results indicate that plyometric training increases lumbar spine bone mass in adolescent girls. Well-designed randomized controlled trials with a proper training period (> 12 weeks) are needed to advocate a specific type of training which has the highest osteogenic effect.

The Impact of Whole Egg Consumption on Bone Accrual in Healthy Children: A Randomized Controlled Trial

Dietary interventions designed to examine the role of nutrition on childhood bone accrual have often focused on the role of individual micronutrients (eg, calcium, vitamin D, and zinc) and macronutrients (eg, protein). The osteogenic benefits of whole foods, such as eggs, are not well understood despite eggs being a source of high-quality nutrients and bioactive compounds known to positively influence bone. A significant positive cross-sectional association between whole egg consumption and tibia cortical bone mass has recently been shown in young children; however, randomized controlled trials (RCTs) have not been conducted. This study is a double-blind RCT in male and female children ages 9-13 years of different ancestries, designed to determine if consuming food products with whole eggs (equivalent to 8-10 eggs/wk) versus foods with milk or gelatin (placebo) over a 9-month period will improve measures of bone strength. Total body less head (TBLH) and lumbar spine bone mineral content (BMC) and areal bone mineral density (aBMD) were assessed using dual-energy X-ray absorptiometry (DXA). DXA Z-scores were computed using published pediatric growth charts and were adjusted for height-for-age Z-score (HAZ). Mid-tibia cortical volumetric BMD, BMC, cortical area, total bone area, cortical thickness, and strength strain index were measured using peripheral quantitative computed tomography. Overall, there were no significant intervention effects for any bone outcomes. The increase in spine BMCHAZ Z-score in the egg group versus the gelatin group approached significance (p = 0.07). Significant time effects in TBLH aBMDHAZ Z-score occurred as all groups decreased over 9 months (p < 0.03). Most tibia cortical bone outcomes increased over time (all p < 0.02), but changes did not differ across intervention groups. Whole eggs provide important nutritional benefits for children, but the bone responses to consumption of 8-10 eggs/wk over a period of 9 months in children entering the early stages of puberty were small. © 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).

Safety, Feasibility, and Acceptability of a Multisite Individualized Exercise Intervention for People with Multiple Myeloma

INTRODUCTION

High rates of disease- and treatment-related symptoms, such as bone lesions, in people with multiple myeloma (MM) create uncertainty on the safety and feasibility of exercise. This study determined the safety, feasibility, and acceptability of an individualized exercise medicine program for people with MM at any disease stage.

METHODS

A multisite, randomized waitlist-controlled trial was conducted of an individualized, high-intensity aerobic, resistance, and impact-loading exercise program. The exercise sessions were supervised twice weekly by accredited exercise physiologists, with one additional unsupervised session per week, for 12 wk. Safety was determined by number of adverse and serious adverse events. Feasibility outcome measures were study eligibility, recruitment, adherence, and attrition. Acceptability was determined by qualitative interviews and subjective levels of enjoyment.

RESULTS

Of 203 people with MM screened, 88% were eligible, with 34% accepting participation (60 people) and 20% attrition for the between-group analysis, meeting a priori criteria (≥25% and <25%, respectively). No adverse or serious adverse events attributed to testing and/or exercise training were reported. Attendance at supervised exercise sessions was 98%, with 45% completion of the home-based exercise sessions. Adherence rates were 35%, 63%, and 34% for the aerobic, resistance, and impact-loading protocols, with 55%, 80%, and 37% of participants meeting a priori criteria (75% of protocol). Acceptability of the exercise program was high (mean, 82%; 95% confidence interval, 78%-87%) and highly supported by qualitative responses.

CONCLUSIONS

An individualized, high-intensity aerobic, resistance, and impact-loading exercise medicine program is safe and acceptable, and feasible by some measures for people with MM. Adherence to the prescribed exercise protocols was limited by comorbidities and disease symptoms. Strategies to improve unsupervised exercise completion are warranted in this population.

Sex Differences in Bone, Muscle, and Inflammatory Markers and Their Associations with Muscle Performance Variables

The importance of various markers such as Sclerostin, Dickkopf-1 (DKK-1), Irisin, receptor activator of NF-kB ligand (RANKL), and Vitamin D have been well studied in bone metabolism. Additionally, inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and Interleukin 6 (IL-6) have been shown to hinder muscle protein synthesis, leading to the loss of muscle and strength. However, a research gap exists in understanding their role in muscle function and physical activity. Therefore, this study aims to explore the serum levels of Sclerostin, DKK-1, Irisin, IL-6, RANKL, Vitamin D, and TNF-α and assess their relationships with upper- and lower-body strength in young adults. In this study, 38 college-aged students (18-23 years), males and females, participated and completed the protocols. The participants' lower and upper body strength were assessed by the vertical jump test (Just Jump, Probotic, AL) with a Tendo FitroDyne (Tendo Sports Machines, Trencin, Slovak Republic) and handgrip (HG) dynamometry (Takei Scientific Instruments, Yashiroda, Japan), respectively. Fasting morning blood samples were analyzed for serum levels of biomarkers by ELISA. The results indicate significant sex differences in Sclerostin, DKK-1, Irisin, and Vitamin D levels (p < 0.05). Furthermore, a positive association was observed between Sclerostin, DKK-1, and Vitamin D, with lower body muscle performance variables (p < 0.05). Conversely, a significant negative correlation was observed between TNF-α and lower-body muscle performance variables (p < 0.05). The results suggest that these markers may have a distinct effect on muscle performance, underscoring the need for further investigation to elucidate the concept of muscle-bone crosstalk.

Effects of Moderate- to High-Impact Exercise Training on Bone Structure Across the Lifespan: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Moderate- to high-impact exercise improves bone mineral density (BMD) across the lifespan, but its effects on bone structure, which predicts fracture independent of areal BMD, are unclear. This systematic review and meta-analysis investigated effects of impact exercise on volumetric BMD (vBMD) and bone structure. Four databases (PubMed, Embase, SPORTDiscus, Web of Science) were searched up to March 2022 for randomized controlled trials (RCTs) investigating the effects of impact exercise, with ground reaction forces equal to or greater than running, compared with sham or habitual activity, on bone vBMD and structure. Bone variables were measured by quantitative computed tomography or magnetic resonance imaging at the tibia, radius, lumbar spine, and femur. Percentage changes in bone variables were compared among groups using mean differences (MD) and 95% confidence intervals (CI) calculated via random effects meta-analyses. Subgroup analyses were performed in children/adolescents (<18 years), adults (18-50 years), postmenopausal women, and older men. Twenty-eight RCTs (n = 2985) were included. Across all studies, impact exercise improved trabecular vBMD at the distal tibia (MD = 0.54% [95% CI 0.17, 0.90%]), total vBMD at the proximal femur (3.11% [1.07, 5.14%]), and cortical thickness at the mid/proximal radius (1.78% [0.21, 3.36%]). There was no effect on vBMD and bone structure at the distal radius, femoral shaft, or lumbar spine across all studies or in any subgroup. In adults, impact exercise decreased mid/proximal tibia cortical vBMD (-0.20% [-0.24, -0.15%]). In postmenopausal women, impact exercise improved distal tibia trabecular vBMD (0.79% [0.32, 1.25%]). There was no effect on bone parameters in children/adolescents in overall analyses, and there were insufficient studies in older men to perform meta-analyses. Impact exercise may have beneficial effects on bone structure and vBMD at various skeletal sites, but additional high-quality RCTs in different age and sex subgroups are needed to identify optimal exercise protocols for improving bone health across the lifespan. © 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).

Determinants of bone parameters in young paediatric cancer survivors: the iBoneFIT project

BACKGROUND

Bone health is remarkably affected by endocrine side effects due to paediatric cancer treatments and the disease itself. We aimed to provide novel insights into the contribution of independent predictors of bone health in young paediatric cancer survivors.

METHODS

This cross-sectional multicentre study was carried out within the iBoneFIT framework in which 116 young paediatric cancer survivors (12.1 ± 3.3 years old; 43% female) were recruited. The independent predictors were sex, years from peak height velocity (PHV), time from treatment completion, radiotherapy exposure, region-specific lean and fat mass, musculoskeletal fitness, moderate-vigorous physical activity and past bone-specific physical activity.

RESULTS

Region-specific lean mass was the strongest significant predictor of most areal bone mineral density (aBMD), all hip geometry parameters and Trabecular Bone Score (β = 0.400-0.775, p ≤ 0.05). Years from PHV was positively associated with total body less head, legs and arms aBMD, and time from treatment completion was also positively associated with total hip and femoral neck aBMD parameters and narrow neck cross-sectional area (β = 0.327-0.398, p ≤ 0.05; β = 0.135-0.221, p ≤ 0.05), respectively.

CONCLUSION

Region-specific lean mass was consistently the most important positive determinant of all bone parameters, except for total hip aBMD, all Hip Structural Analysis parameters and Trabecular Bone Score.

IMPACT

The findings of this study indicate that region-specific lean mass is consistently the most important positive determinant of bone health in young paediatric cancer survivors. Randomised clinical trials focused on improving bone parameters of this population should target at region-specific lean mass due to the site-specific adaptations of the skeleton to external loading following paediatric cancer treatment. After paediatric cancer diagnosis, years from peak height velocity (somatic maturity) is critical for bone development.

Health status, resources, and job demands in geriatric nursing staff: A cross-sectional study on determinants and relationships

BACKGROUND

According to current estimates, the number of people needing care will double in the next 40 years. It is expected that between 130,000 and 190,000 additional nurses will be needed by 2030 in Germany. Physical and psychological burdens associated with nursing in long-term care facilities can develop into serious health risk factors and significantly impact occupational factors such as absenteeism, especially when linked to difficult working conditions. However, demands and resources specific to the nursing profession have not been analyzed extensively to preserve and promote nurses' workability and health adequately.

OBJECTIVE

Our study aimed to examine the extent to which perceived health among geriatric nursing staff in Germany is predicted by personal resources, job demands, and job resources. In addition, we analyzed the impact of different behavior and experience patterns on these relationships.

DESIGN, SETTING, AND PARTICIPANTS

An observational study was conducted between August 2018 and February 2020 in 48 nursing home facilities with 854 staff members in Germany as part of the project 'PROCARE - Prevention and occupational health in long-term care'.

METHODS

The survey contained instruments that measure workplace exposure, musculoskeletal complaints, physical and mental well-being, chronic stress, and work-related behavior and experience patterns. In addition, health-related information on physical activity and nutrition was collected. Data were analyzed using structural equation modeling.

RESULTS

The combined physical and mental workload for geriatric nurses is very high, with 75 % showing chronic stress. In the overall model, job and personal resources have a stronger association with mental health than physical health, while job demands have an equal impact on mental and physical health. Coping behavior also plays an important key role that should be assessed and considered. A behavior and experience risk pattern (health-endangering) is more strongly associated with a lower health status than a health-promoting behavior pattern. Results of the multigroup test showed that work-related behavior and experience patterns significantly moderate the relationship between physical health and mental health (χ2 = 392/p ≤ .001/df = 256/RMSEA = 0.028/CFI = 0.958/TLI = 0.931). Only 43 % show a health-friendly coping pattern.

CONCLUSIONS

Our findings underline the importance of holistic health promotion, which not only aims at changes at the behavioral level and the development of coping strategies but also takes on the task of reducing the workload and including measures to improve the working climate.

TRIAL REGISTRATION NUMBER

DRKS.de (DRKS00015241); August 9, 2018.

TWEETABLE ABSTRACT

Healthier coping patterns can benefit geriatric nurses' health. However, this is not a substitute for improving working conditions.

Non-traditional HIIT-style ROTC training elicits positive bone quality and performance adaptations

Military personnel experience elevated bone injury incidence, partly due to arduous and repetitive training. Non-traditional High-Intensity Interval Training-style (HIIT) may benefit pre-enlisted Reserve Officer Training Corps (ROTC) cadet's musculoskeletal health and performance prior to military service. This study investigated 16 ROTC (n = 12 males; n = 4 females) and 15 physically active sex-, age-, and body mass-matched Controls' musculoskeletal health and performance from November to April. Total body, lumbar spine, and dual- hip dual-energy X-ray absorptiometry scans and 4%, 38%, 66% tibial peripheral quantitative computed tomography scans, blood draws (serum sclerostin and parathyroid hormone), and maximal muscle strength and aerobic capacity testing were completed. From November to April, ROTC improved bone density (DXA) of the dominant total hip and greater trochanter and non-dominant greater trochanter and 38% and 66% tibial total volumetric and cortical bone density (pQCT) similarly or more than Controls (all p ≤ 0.049). From November to April, ROTC also improved bench and leg press, and peak aerobic capacity (all p ≤ 0.013). From November to January, serum sclerostin increased (p ≤ 0.007) and remained elevated through April, while parathyroid hormone was unchanged. HIIT-style training induced positive musculoskeletal adaptations, suggesting it may be an excellent pre-service training modality for this injury prone group.

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.

The Effects of a 1-Year Recreational Kung Fu Protocol on Bone Health Parameters in a Group of Healthy Inactive Young Men

The main aim of the current study was to explore the effects of a 1-year recreational Kung Fu protocol on bone health parameters (bone mineral content (BMC), bone mineral density (BMD), femoral neck geometry and composite indices of femoral neck strength) in a group of healthy inactive young men. 54 young inactive men voluntarily participated in this study, but only 51 of them completed it. The participants were assigned to 2 different groups: control group (n=31) and Kung Fu group (n=20). The Kung Fu group performed two sessions of recreational Kung Fu per week; the duration of each session was 45 minutes. The current study has demonstrated that whole body (WB) BMC, ultra-distal (UD) radius BMD, 1/3 radius BMD, total radius BMD, total forearm BMD, maximal strength, maximum oxygen consumption and jumping performance increased in the Kung Fu group but not in the control group. The percentages of variations in WB BMC, forearm BMD and physical performance parameters were significantly different between the two groups. In conclusion, this study suggests that recreational Kung Fu is an effective method to improve WB BMC, forearm BMD and physical performance parameters in young inactive 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).

Leisure time physical activity and bone mineral density preservation during the menopause transition and postmenopause: a longitudinal cohort analysis from the Study of Women's Health Across the Nation (SWAN)

Background

Whether greater leisure time physical activity (LTPA) is associated with less bone mineral density (BMD) loss during the menopause transition (MT) remains an open question. We hypothesized that: 1) larger increases in LTPA from pre-/early perimenopause (period 1) to late perimenopause/postmenopause (period 2) would be associated with a slower period 2 BMD loss rate; and 2) greater entire-study LTPA levels would be associated with better final absolute BMD (g/cm2).

Methods

Data were from of the Study of Women's Health Across the Nation (1996-2017). Exclusions were: bone beneficial medications, inability to identify start of the MT, and extreme BMD change rates. LTPA measures were a validated ordinal scale and number of metabolic equivalents per hour per week (MET hr wk-1) from sport/exercise. Multiply adjusted, linear regression models estimated: 1) BMD decline rate (annualized %) as a function of LTPA change; and 2) final BMD as a function of entire-study LTPA.

Findings

Median [p25, p75] MET hr wk-1 were 4.2 [0.9, 10.1] and 4.9 [1.4, 11.2] in periods 1 and 2, respectively; walking was the commonest activity. In adjusted models (N = 875), greater increases in LTPA ordinal score and MET hr wk-1 were statistically significantly associated with a slower decline in femoral neck (FN) BMD. Larger entire-study averages of each LTPA measure were statistically significantly related to better final FN and lumbar spine BMD levels.

Interpretation

Findings suggest that LTPA, at modest levels, mitigate MT-related BMD decline and even small increases in intensity, duration or frequency of common activities may lessen bone loss at the population level.

Funding

US-NIH.

Low Bone Mineral Density and Associated Risk Factors in Elite Cyclists at Different Stages of a Professional Cycling Career

PURPOSE

This study aimed to assess the prevalence of low bone mineral density (BMD) in male and female elite cyclists at different stages of a professional cycling career and to identify potential risk factors of low BMD.

METHODS

In this cross-sectional study, 93 male and female early career, advanced career, and postcareer elite cyclists completed dual-energy x-ray absorptiometry at the hip, femoral neck, lumbar spine, and total body; blood sampling; assessment of training history and injuries; and the bone-specific physical activity questionnaire. Backward stepwise multiple regression analyses were conducted to explore associations between BMD and its potential predictors in early and advanced career (i.e., active career) cyclists.

RESULTS

With a mean Z -score of -0.3 ± 0.8, -1.5 ± 1.0, and -1.0 ± 0.9, low BMD ( Z -score < -1) at the lumbar spine was present in 27%, 64%, and 50% of the early, advanced, and postcareer elite male cyclists, respectively. Lumbar spine Z -scores of -0.9 ± 1.0, -1.0 ± 1.0, and 0.2 ± 1.4 in early, advanced, and postcareer elite female cyclists, respectively, indicated low BMD in 45%, 45%, and 20% of these female subpopulations. Regression analyses identified body mass index, fracture incidence, bone-specific physical activity, and triiodothyronine as the main factors associated with BMD.

CONCLUSIONS

Low BMD is highly prevalent in elite cyclists, especially in early career females and advanced career males and females. These low BMD values may not fully recover after the professional cycling career, given the substantial prevalence of low BMD in retired elite cyclists. Exploratory analyses indicated that low BMD is associated with low body mass index, fracture incidence, lack of bone-specific physical activity, and low energy availability in active career elite cyclists.

Using Raw Accelerometer Data to Predict High-Impact Mechanical Loading

The purpose of this study was to develop peak ground reaction force (pGRF) and peak loading rate (pLR) prediction equations for high-impact activities in adult subjects with a broad range of body masses, from normal weight to severe obesity. A total of 78 participants (27 males; 82.4 ± 20.6 kg) completed a series of trials involving jumps of different types and heights on force plates while wearing accelerometers at the ankle, lower back, and hip. Regression equations were developed to predict pGRF and pLR from accelerometry data. Leave-one-out cross-validation was used to calculate prediction accuracy and Bland-Altman plots. Body mass was a predictor in all models, along with peak acceleration in the pGRF models and peak acceleration rate in the pLR models. The equations to predict pGRF had a coefficient of determination (R²) of at least 0.83, and a mean absolute percentage error (MAPE) below 14.5%, while the R² for the pLR prediction equations was at least 0.87 and the highest MAPE was 24.7%. Jumping pGRF can be accurately predicted through accelerometry data, enabling the continuous assessment of mechanical loading in clinical settings. The pLR prediction equations yielded a lower accuracy when compared to the pGRF equations.

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).

The effects of 9 months of formulated whole-egg or milk powder food products as meal or snack replacements on executive function in preadolescents: A randomized, placebo-controlled trial

BACKGROUND

Elevated brain choline is associated with better executive functions in preadolescents. Manipulating dietary choline prospectively in preadolescents using egg supplementation could improve executive functions via effects on brain cellular and neurotransmitter functions.

OBJECTIVES

We tested the 9-month impacts of egg supplementation on executive functions. It was hypothesized that preadolescents who consumed meal or snack replacement products containing powder made from whole eggs would have the largest improvements in executive functions after 9 months compared to those consuming similar products with either added milk powder or gelatin as a placebo.

METHODS

A randomized, parallel-group, double-blinded, placebo-controlled trial design was used. The executive functions of 122 preadolescents (58 females) aged 9-13 were analyzed before and after the 9-month intervention. The primary outcomes were 3 NIH Toolbox-Cognitive Battery measures of executive function: mental flexibility, working memory, and selective attention and inhibitory control. Participants were randomized to consume food products with either: 1) whole egg powder; 2) milk powder; or 3) gelatin as a placebo, all matched on macronutrient content and used as replacements for commonly consumed foods (i.e., waffles, pancakes, macaroni and cheese, ice cream, and brownies). Hypothesis testing used mixed-effects models that included physical activity and sleep scores as covariates.

RESULTS

A statistically significant group × time interaction for selective attention and inhibitory control was found (P = 0.049) for the milk group. This interaction resulted from no change for the placebo group and an improvement in selective attention and inhibitory control performance for the milk group by a T-score of 5.8; the effect size (d) was 0.44 SD units. Other comparisons were statistically insignificant.

CONCLUSIONS

Consumption of foods with added milk powder as a replacement for snacks or meals for 9 months improves selective attention and inhibitory control in preadolescents. Replacement of foods with added whole egg powder does not impact 9-month changes in preadolescent executive functions. This trial was registered at clinicaltrials.gov as NCT03739424.

High-Intensity Exercise and Geometric Indices of Hip Bone Strength in Postmenopausal Women on or off Bone Medication: The MEDEX-OP Randomised Controlled Trial

To compare the effects of high-intensity resistance and impact training (HiRIT) to low-intensity, Pilates-based exercise (LiPBE) on proximal femur geometry and explore the influence of antiresorptive medication on those effects. Postmenopausal women with low bone mass, on or off antiresorptive bone medications were randomly allocated, stratified on medication intake, to eight months of twice-weekly, supervised HiRIT (Onero™) or LiPBE (Buff Bones®). 3D hip software was used to analyse proximal femur DXA scans. Outcomes included femoral neck (FN) and total hip (TH), volumetric (e.g. vBMC, vBMD) and geometric (e.g. cortical thickness, cross-sectional area [CSA], section modulus [Z]) indices of bone strength. Data were analysed using analysis of variance. Scans of 102 women were examined: LiPBE, 43; HiRIT, 37; LiPBE-med, 11; HiRIT-med, 11. HiRIT improved TH trabecular vBMC and vBMD (3.1 ± 1.1% versus - 1.2 ± 1.2%, p = 0.008; and 1.5 ± 1.0% versus - 1.6 ± 1.2%, p = 0.042, respectively) and FN and TH total vBMC (2.0 ± 0.8% versus - 0.2 ± 0.7%, p = 0.032; and 0.7 ± 0.4% versus - 0.8 ± 0.6%, p = 0.032, respectively), compared to losses in LiPBE. HiRIT also increased Z while LiPBE did not (p = 0.035). The combination of HiRIT and medication achieved greater improvements in FN total and trabecular vBMD, total BMC, CSA and Z than HiRIT alone. HiRIT improved geometric parameters of proximal femur strength, while LiPBE exercise was largely ineffective. Medication may enhance some HiRIT effects. Findings suggest reduced hip fracture risk in response to HiRIT.Trial registration number ACTRN12617001511325.

Suboptimal Plasma Vitamin C Is Associated with Lower Bone Mineral Density in Young and Early Middle-Aged Men: A Retrospective Cross-Sectional Study

Background: This study was conducted to evaluate associations between bone mineral density (BMD) and four selected circulating nutrients, particularly vitamin C, among adults aged 20−49 years. Methods: In this retrospective cross-sectional study, the lumbar spine BMD of 866 men and 589 women were measured by dual-energy X-ray absorptiometry and divided into tertiles, respectively. Logistic regressions were used to identify the predictors of low BMD by comparing subjects with the highest BMD to those with the lowest. Results: Multivariate logistic regressions identified suboptimal plasma vitamin C (adjusted odds ratio (AOR) 1.64, 95% confidence interval (CI) 1.16, 2.31), suboptimal serum vitamin B12 (AOR 2.05, 95% CI 1.02, 4.12), and low BMI (BMI < 23) (AOR 1.68, 95% CI 1.12, 2.53) as independent predictors for low BMD in men. In women, low BMI was the only independent predictor for low BMD. Plasma vitamin C, categorized as suboptimal (≤8.8 mg/L) and sufficient (>8.8 mg/L), was positively significantly correlated with the lumbar spine BMD in men, but there was no association in women. Conclusions: Plasma vitamin C, categorized as suboptimal and sufficient, was positively associated with the lumbar spine BMD in young and early middle-aged men. A well-designed cohort study is needed to confirm the findings.

Serum 25-Hydroxyvitamin D is Associated With Bone Microarchitecture and Strength in a Multiracial Cohort of Young Adults

PURPOSE

To determine whether 25-hydroxyvitamin D (25-OH D) levels are associated with bone outcomes in a multiracial cohort of young adults.

METHODS

This cross-sectional study included 165 participants (83 men, 82 women, 18-30 years of age) who self-identified as Asian, Black, or White. We measured bone microarchitecture and strength of the distal radius and tibia using high-resolution peripheral quantitative computed tomography. We used linear regression to estimate the association between 25-OH D (ng/mL) and bone measurements, adjusting for race, sex, age, weight, height, calcium intake, physical activity, and season.

RESULTS

A total of 43.6% of participants were 25-OH D deficient (<20 ng/mL) with greater prevalence in Asian (38.9%) and Black (43.1%) compared with White (18.0%) participants (P < 0.001). At the distal radius, 25-OH D was positively associated with cortical area, trabecular density, cortical thickness, cortical porosity, and failure load (P < 0.05 for all). At the distal tibia, higher 25-OH D was associated with higher cortical area, trabecular density, trabecular number, failure load, and lower trabecular separation and cortical density (P < 0.05 for all). After multivariable adjustment, those with 25-OH D deficiency had generally worse bone microarchitecture than those with 25-OH D sufficiency. Black individuals had largely more favorable bone outcomes than Asian and White individuals, despite higher prevalence of 25-OH D deficiency.

CONCLUSIONS

We found a high prevalence of 25-OH D deficiency in a multiracial cohort of young adults. Lower 25-OH D was associated with worse bone outcomes at the distal radius and tibia at the time of peak bone mass, warranting further attention to vitamin D status in young adults.

Generation of a Reference Dataset to Permit the Calculation of T-scores at the Distal Femur and Proximal Tibia in Persons with Spinal Cord Injury

Persons with traumatic spinal cord injury (SCI) have severe bone loss below the level of lesion with the distal femur (DF) and proximal tibia (PT) being the skeletal regions having the highest risk of fracture. While a reference areal bone mineral density (aBMD) database is available at the total hip (TH) using the combined National Health and Nutrition Examination Survey (NHANES) III study and General Electric (GE) combined (GE/NHANES) to calculate T-score (T-score_GE/NHANES), no such reference database exists for aBMD of the DF, and PT. The primary objectives of this study were (1) to create a reference dataset of young-healthy able-bodied (YHAB) persons to calculate T-score (T-score_YHAB) values at the DF and PT, (2) to explore the impact of time since injury (TSI) on relative bone loss in the DF and PT regions using the two computation models to determine T-score values, and (3) to determine agreement between T-score values for a cohort of persons with SCI using the (T-score_YHAB) and (T-score_GE/NHANES) reference datasets. A cross-sectional prospective data collection study. A Department of Veterans Affairs Medical Center and a Private Rehabilitation Hospital. A normative reference aBMD database at the DF and PT was collected in 32 male and 32 female Caucasian YHAB participants (n=64) and then applied to calculate T-score values at the DF and PT in 105 SCI participants from a historical cohort. The SCI participants were then grouped based on TSI epochs (E-I: TSI < 1y, E-II: TSI 1-5y, E-III: TSI 6-10y, E-IV: TSI 11-20y, E-V: TSI > 20y). N/A. The knee and hip aBMD values were obtained by dual energy X-ray absorptiometry (GE Lunar iDXA) using standard clinical software for proximal femur orthopedic knee software applications. There were no significant differences in mean aBMD values across the four YHAB age subgroups (21-25, 26-30, 31-35, and 36-40 yr of age) at the TH, DF, and PT; mean aBMD values were higher in men compared to the women at all skeletal regions of interest. Using the mean YHAB aBMD values to calculate T-score values at each TSI epoch for persons with SCI, T-score values decreased as a function of TSI, and they continued to decline for 11-20 yr. Moderate kappa agreement was noted between the YHAB and the GE/NHANES reference datasets for the T-score cutoff criteria accepted to diagnose osteoporosis (i.e., SD <-2.5). A homogeneous reference dataset of YHAB aBMD values at the DF and PT was applied to calculate T-score values in persons with chronic SCI. There was a moderate level of agreement at the TH between the YHAB and GE/NHANES reference datasets when applying the conventional T-score cutoff value for the diagnosis of osteoporosis.

A cross-sectional study of the relationship between recreational sporting activity and calcaneal bone density in adolescents and young adults

OBJECTIVE

Childhood and adolescence are critical periods of bone development. Sporting activity is thought to impact peak bone mass acquisition, but most studies have used dual-energy X-ray absorptiometry (DXA) to assess bone health and reported associations between bone mass and elite sporting activity. The objective of this study was instead to assess the relationship between recreational sporting activity (RSA) and another bone assessment, calcaneal quantitative ultrasound (cQUS), in adolescents and young adults.

METHODS

We related recreational sporting activity, assessed through a lifestyle questionnaire, to heel ultrasound bone parameters in a cohort of New Zealand students aged 16-35 years. Complete datasets with data on all relevant confounders (body mass index (BMI), pubertal timing, smoking status, and alcohol consumption) were available for 452 participants. cQUS was performed using a Lunar Achilles EX II machine to obtain bone parameters, broadband ultrasound attenuation (BUA), and speed of sound (SOS); stiffness index (SI) was derived from these measures. All descriptive statistics and statistical analyses were carried out using SPSS Statistics for Macintosh, Version 23.0 (IBM Corp., Armonk, NY, USA). Results are presented as p-values and 95% CI.

RESULTS

Reported lifetime sport participation declined after an individual's mid-teens. Bone cQUS parameters (SI and BUA and T-score) were all positively associated with BMI, and current physical activity (SI, SOS, BUA, T-score, and Z-score) with SI and SOS measures most strongly associated with current high impact and past recreational sporting activity (all p < 0.05).

CONCLUSION

Calcaneal heel ultrasound bone parameters were associated with physical activity, with SI and SOS rather than BUA more strongly related to current and past recreational sporting activity in young New Zealand adults.

Restrictive Eating and Prior Low-Energy Fractures Are Associated With History of Multiple Bone Stress Injuries

Bone stress injuries (BSIs) are common among athletes and have high rates of recurrence. However, risk factors for multiple or recurrent BSIs remain understudied. Thus, we aimed to explore whether energy availability, menstrual function, measures of bone health, and a modified Female Athlete Triad Cumulative Risk Assessment (CRA) tool are associated with a history of multiple BSIs. We enrolled 51 female runners (ages 18-36 years) with history of ≤1 BSI (controls; n = 31) or ≥3 BSIs (multiBSI; n = 20) in this cross-sectional study. We measured lumbar spine, total hip, and femoral neck areal bone mineral density by dual-energy X-ray absorptiometry, bone material strength index using impact microindentation, and volumetric bone mineral density, microarchitecture, and estimated strength by high-resolution peripheral quantitative computed tomography. Participants completed questionnaires regarding medical history, low-energy fracture history, and disordered eating attitudes. Compared with controls, multiBSI had greater incidence of prior low-energy fractures (55% vs. 16%, p = .005) and higher modified Triad CRA scores (2.90 ± 2.05 vs. 1.84 ± 1.59, p = .04). Those with multiBSI had higher Eating Disorder Examination Questionnaire (0.92 ± 1.03 vs. 0.46 ± 0.49, p = .04) scores and a greater percentage difference between lowest and highest body mass at their current height (15.5% ± 6.5% vs. 11.5% ± 4.9% p = .02). These preliminary findings indicate that women with a history of multiple BSIs suffered more prior low-energy fractures and have greater historical and current estimates of energy deficit compared with controls. Our results provide strong rationale for future studies to examine whether subclinical indicators of energy deficit contribute to risk for multiple BSIs in female runners.

Physical activity estimated by osteogenic potential and energy expenditure has differing associations with bone mass in young adults: the raine study

Ground impacts during physical activity may be important for peak bone mass. We found differences in how energy expenditure and impact scores estimated from a physical activity questionnaire related to bone health in young adults. Using both estimate types can improve our understanding of the skeletal benefits of physical activity.

PURPOSE

It is unclear whether mechanical loading during physical activity, estimated from physical activity questionnaires which assess metabolic equivalents of task (METs), is associated with skeletal health. This longitudinal study investigated how physical activity loading scores, assessed at ages 17 and 20 years, (a) compares with physical activity measured in METs, and (b) is associated with bone mass at age 20 years.

METHODS

A total of 826 participants from the Raine Study Gen2 were assessed for physical activity energy expenditure via the International Physical Activity Questionnaire (IPAQ) at age 17 and 20 years. Loading scores (the product of peak force and application rate) per week were subsequently estimated from the IPAQ. Whole-body and appendicular bone mineral density (BMD) at age 20 years were assessed by dual-energy X-ray absorptiometry.

RESULTS

Bland-Altman minimal detectable difference for physical activity Z- scores at age 17 and 20 years were 1.59 standard deviations (SDs) and 1.33 SDs, respectively, greater than the a priori minimal clinically important change of 0.5 SDs. Loading score, but not IPAQ score, had significant positive associations with whole-body and leg BMD after adjustment for covariates (β = 0.008 and 0.012 g/cm², respectively, for age 17 and 20 years loading scores). IPAQ score at age 20 years, but not loading score, had a significant positive association with arm BMD (β = 0.007 g/cm²).

CONCLUSION

This study revealed disagreement in associations of self-reported METs and loading score estimates with bone health in young adults. Coupling traditional energy expenditure questionnaire outcomes with bone-loading estimates may improve understanding of the location-specific skeletal benefits of physical activity in young adults.

Bone health and asymmetry in elite female cricketers

The aim of this study is to determine if bone mineral density (BMD) and bone asymmetry differs between female cricket fast bowlers, spin bowlers and batters. BMD was determined at the total body, lumbar spine, and proximal femurs in 12 fast bowlers, 13 batters and 11 spin bowlers from pre-season DXA scans. High Z-scores at the total body, lumbar spine, and proximal femur were observed in all cricketers (mean Z-scores: +1.4 to +3.3) compared with a general age matched reference population. Fast bowlers had significantly greater BMD on the contralateral side of the lumbar spine compared with the ipsilateral side (p = 0.001, 5.9 - 12.1%). No asymmetry was found between hips in all groups. All cricket positions demonstrated high BMD at all measured sites. The lumbar spine of fast bowlers is asymmetric, with significantly greater BMD on the contralateral side of the spine, particularly at L4, possibly in response to the asymmetric lumbar loading patterns observed in bowling.HIGHLIGHTS Elite female cricketers demonstrate high BMD at total body, lumbar spine and proximal femur sites, regardless of playing position compared with a general age and ethnic group matched reference populationFast bowlers have greater BMD on the contralateral (opposite bowling arm) side of the lumbar spine compared with the ipsilateral side, while a symmetrical pattern was observed in spin bowlers and batters.No asymmetry in BMD or section modulus between hips was observed at any proximal femur site for any cricket position.

Site-Specific Bone Differences and Energy Status in Male Competitive Runners and Road Cyclists

The interaction between mechanical loading and energy availability on bone health in male endurance athletes merits further investigation. The purpose of this study was to compare bone status in male competitive runners and road cyclists and to investigate the influence of energy availability (EA) on bone mineral density (BMD). 18 competitive runners and 19 road cyclists (20-50 years) participated in this study. Areal BMD and body composition were assessed by dual energy x-ray absorptiometry. Volumetric bone variables at the 4% and 66% tibia sites were assessed by peripheral quantitative computed tomography. Energy availability (EA, 7-day dietary and exercise logs) and resting metabolic rate (RMR, open circuit spirometry) were measured as indicators of energy status. Bone loading history, calcium intake, and training history were assessed by questionnaires. After adjusting for age, runners had significantly greater (p < 0.05) areal BMD (femoral neck, left total hip), Z-scores (total body, hips sites), total bone mineral content and trabecular variables (bone mineral content, volumetric BMD, bone strength index) at tibia 4% site, and total volumetric BMD at tibia 66% site than the cyclists (p ≤ 0.05). At the tibia 66% site, cyclists had significantly greater (p < 0.05) total area, periosteal circumference, endosteal circumference, and strength-strain index than runners. Energy variables were similar for runners and cyclists; however, RMR and RMR ratio (measured RMR/predicted RMR) were significantly lower in cyclists (p < 0.001). In conclusion, there were site-specific differences in hip and tibia bone characteristics between runners and cyclists. RMR was associated with several bone outcomes; however, EA was not related to bone health in runners or to dual energy x-ray absorptiometry bone variables in cyclists.

Sclerostin and Dickkopf-1 Characteristics According to Age and Physical Activity Levels in Premenopausal Women

We aimed to compare serum concentrations of sclerostin and DKK-1 in young (20-30 yrs, n = 25) and middle-aged (35-45 yrs, n = 25) premenopausal women and based on physical activity (PA) status. PA status was assessed by the International Physical Activity Questionnaire (low-moderate (≤ 2999 MET-min/week) and high (≥ 3000 MET-min/week). Serum sclerostin and DKK-1 levels were measured in fasting morning blood samples by ELISA. Areal bone mineral density (aBMD) was measured by DXA, and non-dominant tibia bone characteristics were assessed by pQCT. After adjusting for total body aBMD, middle-aged women had significantly (p < 0.001) higher (0.54 ± 0.01 ng/mL) serum sclerostin than young women (0.41 ± 0.01 ng/mL), and sclerostin was positively correlated with age (r_s = 0.065, p ≤ 0.001) and total PA score (r_s = 0.33, p = 0.021). Young women had higher left trochanter aBMD (p = 0.036) than middle-aged women and aBMD variables were higher (all p ≤ 0.043) in the high active group. Middle-aged women had higher 38% cortical vBMD than young women (p = 0.021), otherwise young women had higher values for pQCT variables (all p ≤ 0.036). Sclerostin showed significant correlations (r = 0.32 to 0.58, all p ≤ 0.026) with spine aBMD for the entire cohort and for each age group. Middle-aged women had significant correlations between sclerostin and hip aBMD sites (r = 0.043 to 0.56, all p ≤ 0.031). Sclerostin and cortical vBMD were positively correlated in the entire cohort (r = 0.35 to 0.50; both p < 0.013); split by age group, middle-aged women had positive correlations (r = 0.45 to 0.61 age and, all p ≤ 0.021) between sclerostin and pQCT variables. No significant differences for physical activity were observed for serum DKK-1 concentrations. Serum sclerostin concentrations were positively associated with age and bone characteristics in premenopausal women; however, these findings were not evident for circulating DKK-1. Further research is needed to elucidate the mechanisms for the discordant results in these Wnt inhibitors.

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.

Sex-specific associations among total bone-specific physical activity score, aortic parameters, and body composition in healthy young adults

Background/Objective

Physical inactivity is one of the major cardiovascular disease risk factors; however, not much is known regarding lifetime bone-specific physical activity and arterial stiffness. The aim of this cross-sectional study was to determine whether total bone-specific physical activity score (tBPAQ) was related to arterial stiffness and body composition in healthy young adults.

Methods

Healthy young women (n = 56, 20.3 ± 1.3 years) and men (n = 52, 21.0 ± 1.2 years) between 18 and 25 years were recruited for this study. The tBPAQ was used to obtain a comprehensive account of lifetime bone-loading physical activity. We measured the carotid to femoral pulse wave velocity (cfPWV) to evaluate arterial stiffness using the novel oscillometric device (SphygmoCor XCEL). Dual energy X-ray absorptiometry was used to measure bone free lean body mass (BFLBM, kg) and % total body fat.

Results

Partial correlations analyses showed a significant inverse relationship between tBPAQ and cfPWV (r = - 0.371, p = 0.007) in young women; however, this relationship was not found in young men (p > 0.05). There were significant negative correlations between tBPAQ and % total body fat in both young women (r = - 0.265, p = 0.048) and men (r = - 0.327, p = 0.018). No significant relationships were found between tBPAQ and BFLBM (p > 0.05).

Conclusion

Our study provides preliminary evidence of sex-specificity of negative relationships of tBPAQ with i) cfPWV (women only) and ii) % total body fat (men and women). Whether bone-loading physical activity can lead to better cardiometabolic outcomes needs to be examined.

Age-Related Changes in Bone Density, Microarchitecture, and Strength in Postmenopausal Black and White Women: The SWAN Longitudinal HR-pQCT Study

Higher fracture risk in White versus Black women is partly explained by lower BMD and worse bone microarchitecture in White women. However, whether rates of decline in bone density, microarchitecture and strength differ between postmenopausal Black and White women is unknown. Further, factors that influence rates of age-related bone microarchitecture deterioration remain ill-defined. Thus, over 6.7 years, longitudinal changes were measured in peripheral volumetric bone mineral density (vBMD), microarchitecture, and strength at the distal radius and tibia using HR-pQCT in postmenopausal Black (n = 80) and White (n = 137) women participating in the Study of Women's Health Across the Nation. It was assessed whether age-related changes in vBMD and microarchitecture were influenced by body weight, body composition, and/or weight change. It was found that at the radius, where White women appeared to have slightly greater rates of loss in total vBMD, cortical bone volume, and porosity than Black women, those differences were attenuated after adjusting for clinical covariates. At the tibia, Black and White women had similar rates of bone loss. Independent of race and other clinical covariates, women with the lowest baseline body weight experienced the greatest decline in total and trabecular vBMD at the radius. Furthermore, women who lost weight over the follow-up period had higher rates of bone loss, particularly at the tibia, compared with those who maintained or gained weight. Higher baseline total body fat mass was also protective of bone loss at both the radius and tibia. In conclusion, these findings indicate that lower fracture risk among postmenopausal Black women is not caused by slower rates of bone deterioration, and highlight the importance for postmenopausal women to avoid lower body weight and excessive weight loss to avert rapid bone loss and subsequent fractures. © 2021 American Society for Bone and Mineral Research (ASBMR).

Circulating microRNA responses to acute whole-body vibration and resistance exercise in postmenopausal women

Evaluating alterations in circulating microRNA (c-miRNA) expression may provide deeper insight into the role of exercise in the attenuation of the negative effects of aging on musculoskeletal health. Currently, there are sparse data on c-miRNA responses to acute exercise in postmenopausal women. The purpose of this study was to characterize the effects of acute bouts of resistance exercise and whole-body vibration on expression of selected c-miRNAs in postmenopausal women aged 65-76 years (n=10). We also examined relationships between c-miRNAs and muscle strength and bone characteristics. This randomized crossover design study compared c-miRNA responses to a bout of resistance exercise (RE) (3 sets 10 reps 70% 1 repetition maximum (1RM), 5 exercises) and a bout of whole-body vibration (WBV) (5 sets 1 min bouts 20Hz 3.38mm peak to peak displacement, Vibraflex vibration platform). DXA was used to measure body composition and areal bone mineral density (aBMD) of the total body, AP lumbar spine, and dual proximal femur. pQCT was used to measure tibia bone characteristics (4%, 38%, 66% sites). Blood samples were collected before exercise (Pre), immediately-post (IP), 60 minutes post (60P), 24 hours (24H), and 48 hours (48H) after exercise to measure serum miR-21-5p, -23a-3p, -133a-3p, -148a-3p (qPCR) and TRAP5b (ELISA). There was a significant modality × time interaction for c-miR-21-5p expression (p=0.019), which decreased from 60P to 24H after WBV only. TRAP5b serum concentrations significantly increased IP then decreased below Pre at 24H for both WBV and RE (p<0.01). Absolute changes in TRAP5b were negatively correlated with c-miR-21-5p fold changes (r= -0.642 to -0.724, p<0.05) for both exercise modalities. There were significant negative correlations between baseline c-miRNAs and bone status variables (r= -0.639 to -0.877, p<0.05). Our findings suggest that whole-body vibration is a sufficient mechanical stimulus for altering c-miR-21-5p expression, whereas a high intensity resistance exercise protocol did not elicit any c-miRNA responses in postmenopausal women. Increases in the bone resorption marker, TRAP5b, were associated with greater downregulation of c-miR-21-5p expression.

Acute Response of Sclerostin to Whole-body Vibration with Blood Flow Restriction

Blood flow restriction may augment the skeletal response to whole-body vibration. This study used a randomised, crossover design to investigate the acute response of serum sclerostin and bone turnover biomarkers to whole-body vibration with blood flow restriction. Ten healthy males (mean±standard deviation; age: 27±8 years) completed two experimental conditions separated by 7 days: (i) whole-body vibration (10 1-minute bouts of whole-body vibration with 30 s recovery) or (ii) whole-body vibration with lower-body blood flow restriction (10 cycles of 110 mmHg inflation with 30 s deflation during recovery). Fasting blood samples were obtained immediately before and immediately after exercise, then 1 hour, and 24 hours after exercise. Serum samples were analysed for sclerostin, cross-linked C-terminal telopeptide of type I collagen, and bone-specific alkaline phosphatase. There was a significant time × condition interaction for bone-specific alkaline phosphatase (p=0.003); bone-specific alkaline phosphatase values at 24 hours post-exercise were significantly higher following whole-body vibration compared to combined whole-body vibration and blood flow restriction (p=0.028). No significant time × condition interaction occurred for any other outcome measure (p>0.05). These findings suggest that a single session of whole-body vibration combined with blood flow restriction does not significantly affect serum sclerostin or bone turnover biomarkers.

Associations between nutrition, energy expenditure and energy availability with bone mass acquisition in dance students: a 3-year longitudinal study

Three years of study showed that female and male vocational dancers displayed lower bone mass compared to controls, at forearm, lumbar spine and femoral neck. Energy intake was found to positively predict bone mass accruals only in female dancers at femoral neck. Vocational dancers can be a risk population to develop osteoporosis.

PURPOSE

To determine whether risk factors normally associated with low bone mass in athletic populations (i.e. nutrition intake, energy expenditure and energy availability) are significant predictors of bone mass changes in vocational dance students.

METHODS

The total of 101 vocational dancers (63 females, 12.8 ± 2.2 years; 38 males, 12.7 ± 2.2 years) and 115 age-matched controls (68 females, 13.0 ± 2.1 years; 47 males, 13.0 ± 1.8 years) were monitored for 3 consecutive years. Bone mass parameters were measured annually at impact sites (femoral neck, FN; lumber spine, LS) and non-impact site (forearm) using DXA. Nutrition (3-day record), energy expenditure (accelerometer), energy availability and IGF-1 serum concentration (immunoradiometric assays) were also assessed.

RESULTS

Female and male vocational dancers had consistently reduced bone mass at all anatomical sites (p < 0.001) than controls. IGF-1 did not differ between male vocational dancers and controls, but female dancers showed it higher than controls. At baseline, calcium intake was significantly greater in female vocational dancers than controls (p < 0.05). Male vocational dancers' fat and carbohydrate intakes were significantly lower than matched controls (p < 0.001 and p < 0.05, respectively). Energy availability of both female and male vocational dancers was within the normal range. A significant group effect was found at the FN regarding energy intake (p < 0.05) in female dancers. No significant predictors were found to explain bone mass differences in males.

CONCLUSION

Our 3-year study revealed that both female and male vocational dancers displayed lower bone mass compared to controls, at both impact and non-impact sites. The aetiology of these findings may be grounded on factors different than those usually considered in athletic populations.

Bone mineral density in high-level endurance runners: part A-site-specific characteristics

PURPOSE

Physical activity, particularly mechanical loading that results in high-peak force and is multi-directional in nature, increases bone mineral density (BMD). In athletes such as endurance runners, this association is more complex due to other factors such as low energy availability and menstrual dysfunction. Moreover, many studies of athletes have used small sample sizes and/or athletes of varying abilities, making it difficult to compare BMD phenotypes between studies.

METHOD

The primary aim of this study was to compare dual-energy X-ray absorptiometry (DXA) derived bone phenotypes of high-level endurance runners (58 women and 45 men) to non-athletes (60 women and 52 men). Our secondary aim was to examine the influence of menstrual irregularities and sporting activity completed during childhood on these bone phenotypes.

RESULTS

Female runners had higher leg (4%) but not total body or lumbar spine BMD than female non-athletes. Male runners had lower lumbar spine (9%) but similar total and leg BMD compared to male non-athletes, suggesting that high levels of site-specific mechanical loading was advantageous for BMD in females only and a potential presence of reduced energy availability in males. Menstrual status in females and the number of sports completed in childhood in males and females had no influence on bone phenotypes within the runners.

CONCLUSION

Given the large variability in BMD in runners and non-athletes, other factors such as variation in genetic make-up alongside mechanical loading probably influence BMD across the adult lifespan.

Bone density, microarchitecture and strength in elite figure skaters is discipline dependent

OBJECTIVES

In elite figure skaters, to determine if there was a difference in volumetric bone mineral density and bone strength between 1) figure skaters and population-based normative data, 2) single or pair skaters and ice dancers, and 3) the landing and takeoff legs.

DESIGN

Cross-sectional.

METHODS

Figure skaters had their non-dominant distal radius and bilateral tibia scanned using high-resolution peripheral quantitative computed tomography. Volumetric bone mineral density was determined at the total, cortical and trabecular compartments, and finite element analysis estimated bone strength. Normative data was used to compare the total bone mineral density of figure skaters to a population-based cohort. Independent t-tests compared differences between skating discipline, and paired t-tests compared skeletal parameters for the landing and takeoff leg.

RESULTS

Twenty elite skaters (mean age 22 ± 6.2; female = 11, male = 9) completed scans. Compared with the general population, the mean percentile rank for skaters' total volumetric bone mineral density was below normal at the radius (27th percentile) and normal at the tibia (54th percentile). Single or pair skaters had more robust bone in the landing compared with their takeoff leg. Specifically, the landing leg had higher total bone mineral density (2.8%) and trabecular bone mineral density (6.5%), and superior bone strength (8.5%) than the takeoff leg (p < 0.05).

CONCLUSIONS

Volumetric bone mineral density and strength differences in figure skaters were discipline dependent. Side-to-side differences were observed in single and pair skaters where the landing leg is denser, larger and stronger than the takeoff leg.

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).

Landing Impact Intensities for Jumping Exercises From the OPTIMA-Ex Trial in Trained and Untrained Women

ABSTRACT

Lambert, C, Beck, BR, and Weeks, BK. Landing impact intensities for jumping exercises from the OPTIMA-Ex trial in trained and untrained women. J Strength Cond Res 35(9): 2504-2510, 2021-High-intensity mechanical loads are required to elicit a positive adaptive bone response. Our aim was to quantify the mechanical loads of impact exercises used in each progressive stage of a bone-targeted exercise intervention (the OPTIMA-Ex trial) and to investigate differences in mechanical loads between untrained and trained subjects. A randomized repeated measures experimental design was used to quantify and compare the mechanical loads, including vertical ground reaction force (vGRF) and the rate of loading (RoL) of the landing phase, of all impact exercises applied in the OPTIMA-Ex trial and to determine the load intensity for each training stage of the impact intervention. Fifteen healthy young adult women aged 18-30 years (mean 23.1 ± 3.5 years) were recruited (5 trained and 10 untrained). Overall, vGRF was classified as high impact (>4 times body mass [BM]) for all 7 training stages (4.70 ± 1.89 to 6.79 ± 2.17 BM), whereas RoL ranged from 207.01 ± 175.09 to 371.52 ± 393.43 BM·s-1 across the stages. Furthermore, a significant time effect was observed between training stages for vGRF/BM (p = 0.001) and RoL (p < 0.001). Trained subjects exhibited greater impact loads than untrained subjects for activities at every training stage (p < 0.01). We found that impact activities at every stage of the OPTIMA-Ex trial not only met the GRF criteria for high intensity but also exhibited progressive increases in load for successive stages. Furthermore, trained subjects were capable of producing greater impact loads than untrained subjects.

Sex-Specific Associations Between Bone-Loading Score and Adiposity Markers in Middle-Aged and Older Adults

The authors examined sex-specific relationships between fat mass index (FMI), android/gynoid (A/G) fat ratio, relative skeletal muscle mass index, and Bone-Specific Physical Activity Questionnaire derived bone-loading scores (BLSs) in middle-aged and older adults (men, n = 27; women, n = 33; age = 55-75 years). The FMI, A/G fat ratio, and relative skeletal muscle mass index were estimated by dual-energy X-ray absorptiometry. The Bone-Specific Physical Activity Questionnaire was used to assess: (a) BLSpast (age 1 until 12 months before the study visit), (b) BLScurrent (last 12 months), and (c) BLStotal (average of [a] and [b]) scores. Separate multiple linear regression analysis of (a) age, FMI, and relative skeletal muscle mass index and (b) age, height, and A/G fat ratio versus BLS revealed that FMI and A/G fat ratio were negatively associated with BLSpast and BLStotal (p < .05) in women only. Adiposity and, specifically, central adiposity is negatively related to bone-loading physical activity in middle-aged and older women.

Bone, Biomarker, Body Composition, and Performance Responses to 8 Weeks of ROTC Training

CONTEXT

Military personnel engage in vigorous exercise, often resulting in higher bone mineral density; however, lower leg bone injuries are common in this population. Predictors of change in tibial bone quality and strength need to be characterized in this high-risk population.

OBJECTIVE

This study aimed to examine the effects of an eight-week military training intervention on total body and site-specific bone density and tibial bone quality, serum biomarkers (parathyroid hormone and sclerostin), body composition, and physical performance. Additionally, we sought to investigate what outcome variables (biomarkers, body composition, physical performance) would be predictive of estimated tibial bone strength in college-aged Reserve Officers' Training Corps (ROTC) members.

DESIGN

Prospective Cohort Study.

SETTING

XXX University. Patients of Other Participants: ROTC (n=14 male; n=4 female) were matched for sex, age, and body mass to physically active Controls (n=14 male; n=4 female). ROTC engaged in an eight-week training intervention, while physically active Controls made no changes to their exercise routines.

MAIN OUTCOME MEASURES

Pre general health questionnaires and pre, mid, and post intervention bone scans (DXA, pQCT), serum blood draws (parathyroid hormone and sclerostin), and physical performance measures (muscle strength and aerobic capacity) were tested.

RESULTS

ROTC participants exhibited significantly increased hip bone density and content (all p≤0.03) after the eight-week intervention. Sclerostin, not PTH, was a significant positive correlate and predictor in all ROTC models for estimated bone strength at the fracture prone 38% tibial site. Both groups decreased total body and regional fat mass and ROTC increased aerobic capacity (all p≤0.05).

CONCLUSIONS

All bone, body composition, and performance measures either improved or were maintained in response to ROTC training and sclerostin should be further investigated as a potential early indicator of changes in estimated tibial bone strength in military cohorts.

Peak and Per-Step Tibial Bone Stress During Walking and Running in Female and Male Recreational Runners

BACKGROUND

Athletes, especially female athletes, experience high rates of tibial bone stress injuries (BSIs). Knowledge of tibial loads during walking and running is needed to understand injury mechanisms and design safe running progression programs.

PURPOSE

To examine tibial loads as a function of gait speed in male and female runners.

STUDY DESIGN

Controlled laboratory study.

METHODS

Kinematic and kinetic data were collected on 40 recreational runners (20 female, 20 male) during 4 instrumented gait speed conditions on a treadmill (walk, preferred run, slow run, fast run). Musculoskeletal modeling, using participant-specific magnetic resonance imaging and motion data, was used to estimate tibial stress. Peak tibial stress and stress-time impulse were analyzed using 2-factor multivariate analyses of variance (speed*sex) and post hoc comparisons (α = .05). Bone geometry and tibial forces and moments were examined.

RESULTS

Peak compression was influenced by speed (P < .001); increasing speed generally increased tibial compression in both sexes. Women displayed greater increases in peak tension (P = .001) and shear (P < .001) than men when transitioning from walking to running. Further, women displayed greater peak tibial stress overall (P < .001). Compressive and tensile stress-time impulse varied by speed (P < .001) and sex (P = .006); impulse was lower during running than walking and greater in women. A shear stress-time impulse interaction (P < .001) indicated that women displayed greater impulse relative to men when changing from a walk to a run. Compared with men, women displayed smaller tibiae (P < .001) and disproportionately lower tibial forces (P≤ .001-.035).

CONCLUSION

Peak tibial stress increased with gait speed, with a 2-fold increase in running relative to walking. Women displayed greater tibial stress than men and greater increases in stress when shifting from walking to running. Sex differences appear to be the result of smaller bone geometry in women and tibial forces that were not proportionately lower, given the womens' smaller stature and lower mass relative to men.

CLINICAL RELEVANCE

These results may inform interventions to regulate running-related training loads and highlight a need to increase bone strength in women. Lower relative bone strength in women may contribute to a sex bias in tibial BSIs, and female runners may benefit from a slower progression when initiating a running program.

Preventing Bone Stress Injuries in Runners with Optimal Workload

Bone stress injuries (BSIs) occur at inopportune times to invariably interrupt training. All BSIs in runners occur due to an "error" in workload wherein the interaction between the number and magnitude of bone tissue loading cycles exceeds the ability of the tissue to resist the repetitive loads. There is not a single optimal bone workload, rather a range which is influenced by the prevailing scenario. In prepubertal athletes, optimal bone workload consists of low-repetitions of fast, high-magnitude, multidirectional loads introduced a few times per day to induce bone adaptation. Premature sports specialization should be avoided so as to develop a robust skeleton that is structurally optimized to withstand multidirectional loading. In the mature skeleton, optimal workload enables gains in running performance but minimizes bone damage accumulation by sensibly progressing training, particularly training intensity. When indicated (e.g., following repeated BSIs), attempts to reduce bone loading magnitude should be considered, such as increasing running cadence. Determining the optimal bone workload for an individual athlete to prevent and manage BSIs requires consistent monitoring. In the future, it may be possible to clinically determine bone loads at the tissue level to facilitate workload progressions and prescriptions.

The Effect of Impact Exercise (Alone or Multicomponent Intervention) on Health-Related Outcomes in Individuals at Risk of Fractures: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Exercise is commonly recommended to prevent and manage osteoporosis. High magnitude strains at rapid rate and short bouts should theoretically elicit an osteogenic response; however, the effects of different levels of impact exercises on several outcomes in people at risk of fracture are still unknown.

OBJECTIVE

To report the effect of impact exercise on falls, fractures, adverse events, mortality, bone mineral density (BMD), physical functioning, and health-related quality of life (QoL).

METHODS

We included randomized controlled trials testing the effect of impact exercise compared with a non-exercise control on outcomes in adults ≥ 50 years with low BMD or fragility fractures. Two reviewers selected studies and extracted data. Where possible, we pooled outcomes using mean difference (MD) with a fixed-effects model and 95% confidence interval (CI). We reported risk of bias using Cochrane and certainty of evidence using GRADE.

RESULTS

We included 29 trials; 19 studies evaluated impact exercise alone, and the remaining trials combined impact with resistance or balance training. Impact exercise alone or combined with resistance training improved Timed Up-and-Go values (MD - 0.95 s, 95% CI - 1.09 to - 0.81, low certainty evidence) and lumbar spine (MD 0.04 g/cm², 95% CI 0.02-0.06, low certainty evidence) and femoral neck BMD (MD 0.04 g/cm², 95% CI 0.02-0.07, low certainty evidence). Impact exercise did not improve health-related QoL assessed with QUALEFFO-41 (MD 0.06, 95% CI - 2.18 to 2.30, moderate certainty evidence). The effects of impact exercise on falls, fractures, and mortality are uncertain due to insufficient data. Many trials had a high risk of bias for two or more items.

CONCLUSIONS

There is low certainty evidence that impact exercise may improve physical function and BMD in people at risk of fracture. The effect of impact exercises on falls, fractures, and mortality remains unclear. Our findings should be interpreted with caution due to risk of bias and small sample sizes.

TRIAL REGISTRATION

Registered in Prospero (CRD42018115579) on January 30, 2019.

Muscle Performance Changes with Age in Active Women

The purpose of this study was to examine age-related differences in muscle performance in women divided into young (YW, 20–39 years, n = 29) middle-aged (MAW, 40–59 years, n = 33), and older (OW, ≥60 years, n = 40) age groups. Methods: Hand grip strength, vertical jump performance, and knee extensor (KE) strength (0 deg/s, 60 deg/s, and 240 deg/s), speed of movement (SoM; at 1 Nm, 20%, 40%, and 60% isometric strength), and endurance (30-repetition test at 60 degs/s and 240 deg/s) were assessed. Computed tomography-acquired muscle cross-sectional area (mCSA) was measured and included to determine specific strength (KE strength/mCSA). Results: Hand grip strength was similar across groups, while jump performance declined with age (YW and MAW > OW, p < 0.001). KE strength declined significantly with age (all conditions p < 0.01), while specific strength was similar across groups. SoM was significantly higher for YW and MAW compared to OW (both p < 0.01). An age × velocity interaction revealed YW KE endurance was similar between conditions, whereas MAW and OW displayed significantly better endurance during the 60 deg/s condition. OW displayed impaired KE endurance at 240 deg/s (vs. YW and MAW, p < 0.01) but improved at 60 deg/s (vs. YW, p < 0.01). Dynamic torque decline increased with age (YW < OW, p = 0.03) and was associated with intramuscular adipose tissue (r = 0.21, p = 0.04). Conclusions: Performance declines were most evident among OW, but few performance deficits had emerged in MAW. Interestingly, strength declines disappeared after normalizing to mCSA and endurance appears to be velocity-dependent.

Higher-Impact Physical Activity Is Associated With Maintenance of Bone Mineral Density But Not Reduced Incident Falls or Fractures in Older Men: The Concord Health and Aging in Men Project

High-impact physical activities with bone strains of high magnitude and frequency may benefit bone health. This study aimed to investigate the longitudinal associations between changes in loading intensities and application rates, estimated from self-reported physical activity, with bone mineral density (BMD) changes over 5 years and also with incident falls over 2 years and long-term incident fractures in community-dwelling older men. A total of 1599 men (mean age 76.8 ± 5.4 years) from the Concord Health and Aging in Men Project (CHAMP) were assessed at baseline (2005-2007) and at 2- and 5-year follow-up. At each time point, hip and lumbar spine BMD were measured by dual-energy X-ray absorptiometry, and physical activity energy expenditure over the past week was self-reported via the Physical Activity Scale for the Elderly (PASE) questionnaire. Sum effective load ratings (ELRs) and peak force were estimated from the PASE questionnaire, reflecting the total and highest loading intensity and application rate of physical activities, respectively. Participants were contacted every 4 months over 2 years to self-report falls and over 6.0 ± 2.2 years for fractures. Hip fractures were ascertained by data linkage for 8.9 ± 3.6 years. Compared with sum ELR and PASE scores, peak force demonstrated the greatest standardized effect size for BMD maintenance at the spine (β = 9.77 mg/cm² ), total hip (β = 14.14 mg/cm² ), and femoral neck (β = 13.72 mg/cm² ) after adjustment for covariates, including PASE components (all p < .01). Only PASE scores were significantly associated with reduced falls risk (standardized incident rate ratio = 0.90, 95% confidence interval 0.81-1.00, p = .04). All physical activity measures were significantly associated with reduced incident fractures in univariate analyses, but none remained significant after multivariable adjustments. Older men who engaged in physical activity of high and rapid impact maintained higher BMD, while higher energy expenditure was associated with reduced falls risk. Coupling traditional physical activity data with bone loading estimates may improve understanding of the relationships between physical activity and bone health. © 2020 American Society for Bone and Mineral Research (ASBMR).

Bone mineral density and hip structure changes over one-year in collegiate distance runners and non-athlete controls

Modification of bone is continuous throughout life and influenced by many factors, including physical activity. This study investigated changes in areal bone mineral density (aBMD) and hip structure among male and female collegiate distance runners and non-athlete controls over 12 months. Using dual-energy x-ray absorptiometry (DXA) and hip structure analysis (HSA) software, aBMD at the posterior-anterior (PA) and lateral spine, femoral neck, total hip (TH), whole body (WB), and bone geometry at the narrow neck (NN) of the femur was measured three times over 12 months. HSA included cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), and Z-section modulus (Z). Male runners had significantly higher aBMD at TH and WB and greater CSA, CSMI, and Z than male controls at the end of 12 months. Female controls had higher aBMD at the PA spine than female runners at the end of 12 months. Male runners had significant increases in aBMD at the PA (p = 0.003) and lateral spine (p = 0.002), and TH (p = 0.002), female runners had significant decreases in aBMD at TH (p = 0.015) and WB (p = 0.002), male controls had significant increases in aBMD at the PA spine (p < 0.001) and WB (p < 0.001), and female controls had significant decreases in aBMD at lateral spine and TH (p = 0.008) over the year. When applying covariates of bone-free lean mass and vitamin D, male distance runners demonstrated significant improvement in CSA (3.602 ± 0.139 vs. 3.675 ± 0.122 cm², p = 0.05), CSMI (3.324 ± 0.200 to 3.467 ± 0.212 cm⁴, p < 0.05), and Z (1.81 ± 0.08 to 1.87 ± 0.08 cm³, p = 0.05) during the study. No other changes in hip structure occurred over the year. Distance running may be beneficial to aBMD and hip structure in college-age males but not females. Further research is needed on potential influences of weight-bearing activity, energy availability, and hormonal status on aBMD and hip structure in males and females.

Dominant and nondominant distal radius microstructure: Predictors of asymmetry and effects of a unilateral mechanical loading intervention

Most information about distal radius microstructure is based on the non-dominant forearm, with little known about the factors that contribute to bilateral asymmetries in the general population, or what factors may influence bilateral changes over time. Here, we analyzed bilateral high resolution peripheral quantitative computed tomography (HRpQCT) data collected over a 12-month period as part of a clinical trial that prescribed a well-controlled, compressive loading task to the nondominant forearm. Baseline data from 102 women age 21–40, and longitudinal data from 66 women who completed the 12-month trial, were examined to determine factors responsible for side-to-side asymmetries in bone structure and change in structure over time. Cross-sectionally, the dominant radius had 2.4%–2.7% larger cross-sectional area, trabecular area, and bone mineral content than the nondominant radius, but no other differences were noted. Those who more strongly favored their dominant arm had significantly more, thinner, closely spaced trabecular struts in their dominant versus nondominant radius. Individuals assigned to a loading intervention had significant bilateral gains in total bone mineral density (2.0% and 1.2% in the nondominant versus dominant sides), and unilateral gains in the nondominant (loaded) cortical area (3.1%), thickness (3.0%), bone mineral density (1.7%) and inner trabecular density (1.3%). Each of these gains were significantly predicted by loading dose, a metric that included bone strain, number of cycles, and strain rate. Within individuals, change was negatively associated with age, meaning that women closer to age 40 experienced less of a gain in bone versus those closer to age 21. We believe that dominant/nondominant asymmetries in bone structure reflect differences in habitual loads during growth and past ability to adapt, while response to loading reflects current individual physiologic capacity to adapt.

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We examined relationships between physical activity, handedness, demographics, and asymmetries in distal radius structure.

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Trabecular and cross-sectional area were 2.4-2.7% larger in the dominant side.

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We examined factors that predicted 12-month change after a unilateral loading intervention on the nondominant side.

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The intervention caused unilateral (nondominant) increases in most variables, which scaled with loading dose.

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The results also suggest that greater dietary calcium is associated with endosteal bone apposition following loading.