A High-Intensity Exercise Intervention Improves Older Women Lumbar Spine and Distal Tibia Bone Microstructure and Function: A 20-Week Randomized Controlled Trial

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).

Utility of HR-pQCT in detecting training-induced changes in healthy adult bone morphology and microstructure

Healthy bone adjusts its traits in an exceptionally coordinated, compensatory process. Recent advancements in skeletal imaging via High-Resolution Peripheral Quantitative Computed Tomography (HR-pQCT) allows for the in vivo 3-dimensional and longitudinal quantification of bone density, microarchitecture, geometry, and parameters of mechanical strength in response to varying strain stimuli including those resulting from exercise or military training. Further, the voxel size of 61 microns has the potential to capture subtle changes in human bone in as little as 8 weeks. Given the typical time course of bone remodeling, short-term detection of skeletal changes in bone microstructure and morphology is indicative of adaptive bone formation, the deposition of new bone formation, uncoupled from prior resorption, that can occur at mechanistically advantageous regions. This review aims to synthesize existing training-induced HR-pQCT data in three distinct populations of healthy adults excluding disease states, pharmacological intervention and nutritional supplementation. Those included are: 1) military basic or officer training 2) general population and 3) non-osteoporotic aging. This review aims to further identify similarities and contrasts with prior modalities and cumulatively interpret results within the scope of bone functional adaptation.

What are the Effects of Exercise on Trabecular Microarchitecture in Older Adults? A Systematic Review and Meta-analysis of HR-pQCT Studies

The objective of this review was to determine the effects of exercise on high-resolution peripheral quantitative computed tomography (HR-pQCT) derived trabecular microarchitecture parameters in older adults. Five electronic databases were systematically searched by two independent reviewers. Inclusion criteria were adults age ≥ 50, any type of exercise as part of the intervention, and trabecular microarchitecture assessed via HR-pQCT. Data was extracted from included studies, and where suitable, included in a meta-analysis. Quality of included studies was appraised. Seven studies (397 participants) were included. All participants were postmenopausal women. Interventions included jumping, whole-body vibration, and power/plyometric training. All studies were rated as either weak or moderate quality. Meta-analysis (5 studies) showed no significant changes in any parameters when considering all exercise or sub-analysing based on type. Exercise was not found to have significant effects on trabecular microarchitecture in postmenopausal women over the age of 50. These findings should be interpreted with caution due to the small number of studies investigating few modes of exercise, their weak to moderate quality, and risk of bias. High-quality studies are needed to determine the effects of additional types of exercise in a more diverse population of older adults, including men.

The Role of High-intensity and High-impact Exercises in Improving Bone Health in Postmenopausal Women: A Systematic Review

Postmenopausal osteoporosis is a chronic condition with decreased bone mass and altered bone structure, leading to a greater risk of fractures among older women. Exercise has been proposed as a potentially effective non-pharmacological method to prevent this condition. In this systematic review, we investigate the effects and safety of high-impact and high-intensity exercises in improving bone density at popular sites of fragility fractures, namely, the hip and spine. This review also highlights the mechanism of these exercises in improving bone density and other aspects of bone health in postmenopausal women.  This study is done adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. After applying the eligibility criteria, we selected 10 articles from PubMed and Google Scholar to be included in our study.  Based on the findings from the studies, we established that high-intensity and high-impact exercises are effective in improving, or at the very least maintaining, bone density in the lumbar spine and femur in postmenopausal women. An exercise protocol including high-intensity resistance exercises and high-impact training is shown to be most effective in improving bone density and other parameters of bone health. These exercises were found to be safe in older women, however, careful supervision is recommended. All limitations considered, high-intensity and high-impact exercises are an effective strategy to enhance bone density, and potentially reduce the burden of fragility as well as compression fractures in postmenopausal women.

Effect of high-intensity training on bone health and body composition in lung transplant recipients: A secondary analysis of a randomized controlled trial

BACKGROUND

Loss of bone mineral and skeletal muscle mass is common after lung transplantation (LTx), and physical activity (PA) may prevent further deterioration. We aimed to assess the effects of 20-week high-intensity training (HIT) on body composition, bone health, and PA in LTx recipients, 6-60 months after surgery.

METHODS

In a randomized controlled trial, 51 LTx recipients underwent Dual-energy X-ray absorptiometry (DXA), and PA level and sedentary time were objectively recorded by accelerometers for seven consecutive days. Of these, 39 participants completed the study, including 19 participants in the HIT group and 20 participants in the standard care group.

RESULTS

Following the intervention, ANCOVA models revealed a nonsignificant between-group difference for change in lean body mass (LBM) and bone mineral density (BMD) of the lumbar spine of 0.4% (95% CI = -3.2, 1.5) (p = .464) and 1.0% (95% CI=-1.3, 3.4) (p = .373), respectively. Trabecular bone score (TBS) of the lumbar spine (L1-L4), however, increased by 2.2 ± 5.0% in the exercise group and decreased by -1.6 ± 5.9% in the control group, giving a between-group difference of 3.8% (95% CI=0.1, 7.5) (p = .043). There were no between-group differences in PA or sedentary time.

CONCLUSION

High-intensity training after LTx improved TBS significantly, but not PA, LBM or BMD.

Differences in the effects of BMI on bone microstructure between loaded and unloaded bones assessed by HR-pQCT in Japanese postmenopausal women

Objectives

The relationship between weight-related load and bone mineral density (BMD)/bone microstructure under normal load conditions using high-resolution peripheral quantitative computed tomography (HR-pQCT) remains unconfirmed. The study aims to investigate the differences in effect of body mass index (BMI) on BMD/bone microstructure of loaded and unloaded bones, respectively, in Japanese postmenopausal women.

Methods

Fifty-seven postmenopausal women underwent HR-pQCT on the tibia and radius. Correlation analysis, principal component (PC) analysis, and hierarchical multiple regression were performed to examine the relationship between BMI and HR-pQCT parameters.

Results

Several microstructural parameters of the tibia and radius correlated with BMI through a simple correlation analysis, and these relationships remained unchanged even with an age-adjusted partial correlation analysis. PC analysis was conducted using seven bone microstructure parameters. The first PC (PC1) reflected all parameters of trabecular and cortical bone microstructures, except for cortical porosity, whereas the second PC (PC2) reflected only cortical bone microstructure. Hierarchical multiple regression analysis indicated that BMI was more strongly related to BMD/bone microstructure in the tibia than in the radius. Furthermore, BMI was associated with trabecular/cortical BMD, and PC1 (not PC2) of the tibia and radius. Thus, BMI was strongly related to the trabecular bone microstructure rather than the cortical bone microstructure.

Conclusions

Our data confirmed that BMI is associated with volumetric BMD and trabecular bone microstructure parameters in the tibia and radius. However, although BMI may be more related to HR-pQCT parameters in the tibia than in the radius, the magnitude of association is modest.

Physical and lifestyle factors associated with trabecular bone score values

TBS is associated with age, weight, childhood physical activity, and BMD in men and age, height, BMD, and mobility in women.

INTRODUCTION

Trabecular bone score (TBS) indirectly assesses trabecular microarchitecture at the lumbar spine, providing complementary information to areal BMD. Many studies have investigated the relationships between BMD and lifestyle factors known to affect bone, but such research is limited for TBS. The aim of this study was to assess the relationship between TBS and lifestyle factors in Australian men and women.

METHODS

This cross-sectional study involved 894 men and 682 women (ages 24-98 years) enrolled in the Geelong Osteoporosis Study. TBS was assessed by analysis of lumbar spine DXA scans (Lunar Prodigy) using TBS iNsight software (Version 2.2). Bivariate and multivariable linear regression models were used to explore the associations between TBS and physical and lifestyle factors, including anthropometry, alcohol consumption, childhood physical activity, mobility, smoking status, prior low trauma fracture, medication use, and intakes of calcium and vitamin D.

RESULTS

In bivariate regression modelling, low mobility and the use of antiresorptive medication were associated with lower TBS in both men and women. Low childhood physical activity was also associated with lower TBS in men. Prior fracture, use of glucocorticosteroids, and total calcium intake were also associated with lower TBS in women. The final adjusted model for men included age, weight, childhood physical activity, and BMD, and for women, age, height, BMD, and mobility. No interaction terms were identified in the models.

CONCLUSIONS

Lower TBS is associated with older age, increased weight, low childhood physical activity, and lower BMD in men and older age, shorter stature, lower BMD, and low mobility in women.