The Impact of Different Modes of Exercise Training on Bone Mineral Density in Older Postmenopausal Women: A Systematic Review and Meta-analysis Research

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

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

Comparison of trabecular bone microarchitecture between older males with and without a running habit: A cross-sectional study

Objectives

Despite its prevalence among seniors, the impact of running on trabecular bone microarchitecture, especially in weight-bearing sites, remains relatively unexplored. This cross-sectional study aimed to investigate the impact of habitual running on bone health, specifically bone mineral density (BMD) and trabecular bone microarchitecture, in male older adults.

Methods

Twenty-five male recreational runners aged between 50 and 75 years old were recruited in this study (RUN; average running experience 7.5 ± 6.0 years, average monthly running volume 217 ± 120 km), and 25 age matched sedentary older males served as controls (CON). Dual-energy X-ray absorptiometry was used to obtain bone mineral density (BMD) measures at whole-body, bilateral proximal femur as well as lumbar spine for all participants. Magnetic resonance imaging was used to obtain trabecular bone microarchitectural parameters at distal femur and distal tibia for all participants.

Results

Findings revealed no significant difference in BMD between groups for all measured sites (all p > 0.05; d range 0.013-0.540). However, runners displayed higher bone volume fraction and trabecular thickness at the distal tibia (p = 0.012 and 0.001; 95 % CI of MD [-0.030, -0.004] and [-0.013, -0.004]; d = 0.739 and 1.034, respectively) and higher trabecular thickness at the distal femur (p = 0.002; 95 % CI of MD [-0.010, -0.002]; d = 0.907).

Conclusions

This study provides critical insights into the relationship between running and bone health in older adults, suggesting regular recreational running may positively influence trabecular bone microarchitecture, potentially enhancing bone strength and reducing fracture risk. These findings pave the way for future research to develop evidence-based exercise recommendations for an aging population.

Six Weeks to Wellness: The Role of Breathing Exercises Based on Motor Development Pattern in Improving Fitness and Quality of Life in Overweight Elderly Women

Background: Being overweight is a major global health epidemic of the 20th and 21st centuries, which can affect the movement system function of older adult women. This study evaluated the effects of a breathing exercise based on motor development patterns on functional fitness and quality of life in overweight older adult women. Methods: A randomized controlled trial was conducted with 40 community-dwelling women aged 65-75. Participants were randomly assigned to an intervention group, which completed a 6-week breathing exercise program (three supervised and three home-based sessions per week), or a control group, which maintained usual routines. Outcome measures included cardiovascular fitness, upper and lower body flexibility, muscle strength, dynamic balance, and quality of life, assessed at baseline and post-intervention. Results: The intervention group showed significant improvements in cardiovascular fitness (p < .001, ES = 0.652), upper body flexibility (p < .001, ES = 0.652), lower body flexibility (p < .001, ES = 0.538), upper body strength (p < .001, ES = 0.538), lower body strength (p < .001, ES = 0.538), and dynamic balance (p < .001, ES = 0.475) compared to the control group. Quality of life also significantly improved in the intervention group (p < .001, ES = 0.475). Conclusion: Breathing exercises based on motor development patterns significantly enhance functional fitness and quality of life in overweight older adult women. Incorporating these exercises into regular physical activity routines may promote health and independence in older adults. Further research should explore long-term benefits and optimal exercise parameters for older adults.

Effects of resistance training, Yijinjing and Baduanjin exercise with oral caltrate D on bone mineral density and bone metabolism in older women: a randomised controlled trial

BACKGROUND

The literature lacks studies comparing the effects of traditional Chinese exercises, Qigong Yijinjing (YJJ) and Baduanjin (BDJ), with resistance training (RT) on bone mineral density (BMD) and bone metabolism in older adults.

OBJECTIVE

This study investigated the effects of regular RT, YJJ, and BDJ exercises training, combined with oral Caltrate D supplementation, on lumbar spine and proximal femur BMD and serum bone metabolism indices in older women.

METHODS

Eighty-four older women were randomly divided into the RT group (RG, n = 21), YJJ group (YG, n = 22), BDJ group (BG, n = 21) and control group (CG, n = 20). These groups performed the assigned exercises for 24 weeks (3 times/week, 60 min/time). The BMD of the lumbar L2-4 and proximal femur, as well as serum bone metabolism indices, were measured using dual-energy X-ray absorptiometry and an automatic chemiluminescence apparatus, respectively.

RESULTS

At week 24, compared to the CG, the RG, YG, and BG had significantly higher BMD and procollagen type I N-terminal propeptide (PINP) levels in the lumbar L2-4 region (BMD: p = 0.049, p = 0.016, p = 0.040; PINP: p = 0.026, p = 0.029, p = 0.020), and lower β-carboxy-terminal cross-linked telopeptide of type 1 collagen (β-CTX) levels (p = 0.001, p = 0.012, p = 0.042). Intragroup comparison between baseline and week 24 data revealed that in RG, YG, and BG, lumbar L2-4 BMD (RG: p = 0.036, YG: p = 0.002, BG: p = 0.022) and PINP (RG: p = 0.020, YG: p = 0.001, BG: p = 0.001) increased, whereas β-CTX (RG: p = 0.003, YG: p < 0.001, BG: p = 0.008) decreased.

CONCLUSIONS

RT, YJJ and BDJ combined with Caltrate D for 24 weeks can increase lumbar BMD, increase the bone formation marker PINP and decrease the bone resorption marker β-CTX in older women but had no significant effect on the BMD of the proximal femur. YJJ and BDJ had the same effect on improving BMD in the older adults as RT with the same exercise cycle and frequency.

Dairy and Exercise for Bone Health: Evidence from Randomized Controlled Trials and Recommendations for Future Research

PURPOSE OF REVIEW

To examine evidence from randomized controlled trials (RCTs) on how modifiable factors such as exercise and nutrition, with a focus on dairy products, play a role in improving bone health across the lifespan.

RECENT FINDINGS

Meta-analyses of RCTs demonstrate the advantages of consuming dairy products to improve bone mineral density/content (BMD/BMC) and markers of bone metabolism and turnover (BTMs). Eighteen RCTs were conducted investigating the combined effects of dairy and exercise, with most indicating a benefit in youth and adult populations. Results were less conclusive in older adults, perhaps due to altered requirements for dairy/nutrients and exercise with increased age.   RCTs demonstrate that dairy product consumption alone benefits bone health and can enhance the effects of exercise on bone. This may help improve skeletal growth and development in adolescence and prevent osteoporosis with increased age. Future RCTs should account for habitual nutrient intakes, and dairy dosage, timing, and matrix effects.

Primary Osteoporosis Induced by Androgen and Estrogen Deficiency: The Molecular and Cellular Perspective on Pathophysiological Mechanisms and Treatments

Primary osteoporosis is closely linked to hormone deficiency, which disrupts the balance of bone remodeling. It affects postmenopausal women but also significantly impacts older men. Estrogen can promote the production of osteoprotegerin, a decoy receptor for RANKL, thereby preventing RANKL from activating osteoclasts. Furthermore, estrogen promotes osteoblast survival and function via activation of the Wnt signaling pathway. Likewise, androgens play a critical role in bone metabolism, primarily through their conversion to estrogen in men. Estrogen deficiency accelerates bone resorption through a rise in pro-inflammatory cytokines (IL-1, IL-6, TNF-α) and RANKL, which promote osteoclastogenesis. In the classic genomic pathway, estrogen binds to estrogen receptors in the cytoplasm, forming a complex that migrates to the nucleus and binds to estrogen response elements on DNA, regulating gene transcription. Androgens can be defined as high-affinity ligands for the androgen receptor; their combination can serve as a ligand-inducible transcription factor. Hormone replacement therapy has shown promise but comes with associated risks and side effects. In contrast, the non-genomic pathway involves rapid signaling cascades initiated at the cell membrane, influencing cellular functions without directly altering gene expression. Therefore, the ligand-independent actions and rapid signaling pathways of estrogen and androgen receptors can be harnessed to develop new drugs that provide bone protection without the side effects of traditional hormone therapies. To manage primary osteoporosis, other pharmacological treatments (bisphosphonates, teriparatide, RANKL inhibitors, sclerostin inhibitors, SERMs, and calcitonin salmon) can ameliorate osteoporosis and improve BMD via actions on different pathways. Non-pharmacological treatments include nutritional support and exercise, as well as the dietary intake of antioxidants and natural products. The current study reviews the processes of bone remodeling, hormone actions, hormone receptor status, and therapeutic targets of primary osteoporosis. However, many detailed cellular and molecular mechanisms underlying primary osteoporosis seem complicated and unexplored and warrant further investigation.

Twelve-month resistance and impact exercise program or risedronate provides a relative benefit to hip bone structure in postmenopausal women: results from a randomized controlled trial

Bone strength estimates are important for fracture prevention. This study compared bone strength changes in postmenopausal women with low bone mass who were assigned to 12 months of exercise, a bone medication, or control. Exercise and bone medications benefited structure at the hip. Structure should be considered in fracture prevention research.

PURPOSE

Exercise and bisphosphonates reduce fracture risk, but their impact on estimates of bone strength remains uncertain. This study compared changes in tibial bone strength using peripheral quantitative computed tomography (pQCT) and hip structure analysis (HSA) outcomes from dual-energy X-ray absorptiometry (DXA) scans in postmenopausal women with low bone mass assigned to 12 months of exercise, risedronate, or control.

METHODS

In this RCT, 276 postmenopausal women within 6 years of menopause were randomly assigned to three groups: exercise (92), risedronate (91), or control (93). Exercise included weighted jogging and progressive resistance exercises; risedronate treatment was 150 mg monthly; all groups received calcium and vitamin D. pQCT and DXA images were obtained at baseline and 6 and 12 months and compared between groups over time.

RESULTS

Participants had a mean (± SD) age of 54.5 (± 3.2) years with an average of 36.7 (± 40.7) months postmenopause. No significant differences were found between groups for the change in pQCT outcomes (volumetric bone mineral density, area, and strength estimates). At 12 months, mean percent differences (95% CI) in HSA measures between exercise and controls were as follows: intertrochanteric, cross-sectional area 2.25% (0.28, 4.12) (p = .03), cross-sectional moment of inertia (CSMI) 5.67% (1.47, 9.87) (p < .01), and section modulus (SM) 4.38% (1.02, 7.74) (p = .01), and narrow neck, average cortical thickness 2.37% (-0.08, 4.83) (p = .031). Mean percent differences (95% CI) in HSA measures between risedronate and control were as follows: intertrochanteric, CSMI 4.28% (-0.24, 8.81) (p = .03) and SM 3.35% (-0.21, 6.91) (p = .03), and shaft, subperiosteal width 0.82% (0.05, 1.58) (p = .047), CSMI 2.53% (0.88, 4.18) (p = .004), and SM 1.57% (0.34, 2.8) (p = .008). Exercise maintained neck-shaft angle compared to both control 1.27% (0.13, 2.41) (p = .04) and risedronate 1.31% (0.23, 2.39) (p = .03). All other differences for changes in HSA outcomes over time were not significantly different between the exercise and risedronate groups.

CONCLUSION

Exercise and bisphosphonates may influence structural and strength estimates at the hip, but not at peripheral sites (tibia). Neither exercise nor bisphosphonates were found to be superior in improving estimates of hip bone strength.

Effect of educational intervention on preventing osteoporosis in postmenopausal women

In the experimental group, the average scores of knowledge, constructs of theory of planned behavior, nutrition, and walking had a significant enhancement compared to the control group after the educational intervention. After the intervention, the value of the lumbar spine bone mineral density T-score in the experimental group increased, while in the control group, it decreased.

INTRODUCTION

Osteoporosis is a global public health problem currently affecting millions of people worldwide and in Iran. This study was conducted to assess the effect of an educational intervention based on the theory of planned behavior on the prevention of osteoporosis in postmenopausal women.

METHODS

This quasi-experimental study was performed on 160 women aging over 50 who were referred to health centers in Fasa City, Iran, in 2019. A simple random sampling method was applied to assign the participants into control and intervention groups (80 participants for each group). Data were gathered by questionnaires arranged based on the constructs of the theory of planned behavior, nutrition performance, and walking performance. The educational intervention included seven 50-minute educational sessions. The obtained data were analyzed using SPSS 22 software and Chi-square test, independent T-test, and paired T-test, and the significance level was considered 0.05.

RESULTS

The mean ages of the studied participants in the experimental and control groups were 59.18 ± 6.56 and 57.92 ± 5.70, respectively. In the experimental group, the average scores of knowledge, constructs of the theory of planned behavior, nutrition performance, and walking performance had a significant enhancement compared to the control group one year after the intervention (p < 0.001). At 12 months after the intervention, the value of the lumbar spine bone mineral density T-score in the experimental group increased, while in the control group, it reduced (p < 0.001).

CONCLUSIONS

The theory of planned behavior affected nutrition and walking performance in osteoporosis prevention of subjects. This theory can be used as a framework for designing and performing educational interventions for preventing osteoporosis and promoting women's health.

Effect of Whole-Body Vibration on Balance or Proprioception in Nonspecific Chronic Low Back Pain: A Systematic Review

Objective

This systematic review aimed to investigate the effect of whole-body vibration (WBV) on balance or proprioception for patients with nonspecific chronic low back pain (NSCLBP).

Methods

A comprehensive search was conducted using 5 databases-PubMed, Web of Science, Cochrane Library, Science Direct, and Physiotherapy Evidence Database-from inception to January 2022. Randomized clinical trials that examined the efficacy of WBV on balance or proprioception in patients with NSCLBP were incorporated. The methodological quality of each included study was assessed using the Physiotherapy Evidence Database scale.

Results

Our search strategy yielded 5309 articles, of which 7 published randomized clinical trials (313 patients) met the inclusion criteria. Three of the 4 included studies that investigated balance reported significant improvements after WBV, of which 2 were of high methodological quality. The remaining 3 studies investigating proprioception also showed significant improvements after WBV intervention.

Conclusion

Although some studies seem to provide promising results regarding the efficacy of WBV or WBV combined with exercise in improving balance and proprioception in patients with NSCLBP, at present, no definite conclusions can be drawn due to article heterogeneity and lack of clinical trials.

What is the evidence for the effect of physical exercise on bone health in menopausal women? An umbrella systematic review

This study aimed to analyze the effects of physical exercise (PE) on bone health in menopausal women through an umbrella review and to assess the quality of systematic reviews (SRs) and meta-analyses (MAs) included. The review was registered in PROSPERO (CRD42020208130) and the Rayyan application was used. The methodological quality of the included studies was evaluated by A MeaSurement Tool to Assess Systematic Reviews (AMSTAR), and Grading of Recommendations Assessment, Development and Evaluation (GRADE) was applied to assess the level of evidence of the results. The results showed that low-intensity jumping exercises with longer sessions proved to be efficient in the hip segment. Swimming requires further investigation, as it showed high heterogeneity. Aerobic and resistance exercises showed inconsistent results, requiring further studies with these modalities of PE. Concurrent training showed improvements in the lumbar spine, femoral neck, Ward's triangle and trochanter. Finally, combined resistance exercises are effective in preserving bone mineral density (BMD) of the femoral neck and lumbar spine in postmenopausal women. In conclusion, jumping exercises were efficient in the hip, while aerobic and resistance exercises are still inconsistent. Concurrent training showed improvements in BMD of the lumbar spine, femoral neck, Ward's triangle and trochanter. Finally, combined resistance protocols are effective in preserving BMD of the femoral neck and lumbar spine in postmenopausal women.

Resistance training alters body composition in middle-aged women depending on menopause - A 20-week control trial

BACKGROUND

Resistance training (RT) is effective in counteracting the age- and menopause-related loss of muscle mass (MM) and strength in middle-aged women (40-60 years). Research on RT with free weights is limited in pre- and post-menopausal women. Based on this, a 20-week training intervention was conducted with this population to investigate the effects of systematic RT with free weights on strength capacity and body composition.

METHOD

Forty-one healthy women (52.0 ± 3.6 years) participated in this study. After 10-week control phase (no RT, T0-T1) followed by a 10-week intervention phase (T1-T2) with RT twice a week and 6-8 sets of each muscle per week. Subjects were randomly assigned to a low-intensity (50% 1-RM) or moderate-intensity (75% 1-RM) RT group and divided into pre-menopausal and post-menopausal according to their hormone profile. Fat-free mass (FFM), MM, fat mass (FM), muscle thickness (Vastus lateralis (VL), Rectus femoris (RF), Triceps brachii (TB)), grip strength, 1-RM squat and bench press were assessed before and after each phase. Statistical analysis was performed using a linear mixed model to account for fixed (time and group) and random (individual) effects.

RESULTS

A total of 31 women successfully completed the study. No injuries occurred during the intervention. Significant increases in 1-RM squat and bench press were observed in all groups. No interaction effect was observed for the strength parameters. In pre-menopausal women, FFM, MM and RF muscle thickness increased significantly, while VL showed a trend. These effects were not present in post-menopausal women regardless of RT intensity.

CONCLUSION

RT with free weight is safe and effective for middle-aged women to increase 1-RM. Hypertrophy effects were found exclusively in pre-menopausal women. To achieve hypertrophy and/or body composition changes in post-menopausal women, larger training volumes (> 6-8 sets/muscle per week) are likely required.

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.

Effect of a 3-month L-carnitine supplementation and resistance training program on circulating markers and bone mineral density in postmenopausal women: a randomized controlled trial

BACKGROUND

Higher circulating levels of trimethylamine N-oxide (TMAO), which is a metabolite that can be produced by the gut microbiota from L-carnitine (LC), have been associated with bone mineral density (BMD). Because LC supplementation can improve bone density and microstructural properties in animal models, this study aimed to examine the effects of 12 weeks of LC supplementation on BMD and selected blood markers involved in bone metabolism of postmenopausal women participating in a resistance training (RT) program.

METHODS

Twenty-seven postmenopausal women, who had not been treated for osteoporosis, with a total T-score above - 3.0 and no diet differences completed 12 weeks of RT. The participants' diets were supplemented with either 1 g of LC-L-tartrate and 3 g of leucine per day (LC group) or 4 g of leucine per day as a placebo (PLA group), in a double-blind fashion.

RESULTS

After the intervention in the LC group, plasma total carnitine and serum decorin levels were higher than the corresponding preintervention values (p = 0.040 and p = 0.042, respectively). Moreover, plasma TMAO and serum SPARC levels were higher in the LC group than the corresponding postintervention values in the PLA group (p < 0.001 and p = 0.030, respectively). No changes in the BMD were observed after 3 months of the intervention.

CONCLUSIONS

Twelve weeks of LC supplementation during RT program increased plasma TMAO levels and appeared to affect signaling molecules, as indicated by the increase in the resting SPARC and decorin levels, with no significant modification in the BMD.

TRIAL REGISTRATION

Retrospectively registered at the ClinicalTrials.gov (NCT05120011).

Leveraging mice with diverse microbial exposures for advances in osteoimmunology

The skeletal and immune systems are intricately intertwined within the bone marrow microenvironment, a field of study termed osteoimmunology. Osteoimmune interactions are key players in bone homeostasis and remodeling. Despite the critical role of the immune system in bone health, virtually all animal research in osteoimmunology, and more broadly bone biology, relies on organisms with naïve immune systems. Drawing on insights from osteoimmunology, evolutionary anthropology, and immunology, this perspective proposes the use of a novel translational model: the dirty mouse. Dirty mice, characterized by diverse exposures to commensal and pathogenic microbes, have mature immune systems comparable to adult humans, while the naïve immune system of specific-pathogen free mice is akin to a neonate. Investigation into the dirty mouse model will likely yield important insights in our understanding of bone diseases and disorders. A high benefit of this model is expected for diseases known to have a connection between overactivation of the immune system and negative bone outcomes, including aging and osteoporosis, rheumatoid arthritis, HIV/AIDS, obesity and diabetes, bone marrow metastases, and bone cancers.

Resistance training for postmenopausal women: systematic review and meta-analysis

IMPORTANCE

Numerous studies have been published assessing the effects of resistance muscle training to mitigate menopausal symptoms, given the endocrine muscle function and its metabolic regulation. Therefore, mapping and synthesizing high-quality studies are necessary to help clinical decisions.

OBJECTIVE

The aim of this study was to assess the effects (benefits and harms) of resistance muscle training for postmenopausal women.

EVIDENCE REVIEW

Electronic searches were conducted in MEDLINE (via PubMed), EMBASE, CENTRAL, PEDro, LILACS, and SPORTDiscus up to December 2021. Two independent reviewers selected the retrieved references and extracted relevant data from included studies. The methodological quality (risk of bias) using the Cochrane Risk of Bias table and the certainty of the evidence (GRADE approach) were assessed.

FINDINGS

Twelve randomized clinical trials (n = 452) with unclear to high risk of bias were identified. Compared with no exercise, resistance training (up to 16 weeks) seems to promote an improvement in functional capacity (mean difference [MD], 2.90 points; 95% CI, 0.60-5.20) and bone mineral density (MD, 0.10; 95% CI, 0.10-0.10) and a reduction in the hot flash frequency (13/29 vs 1/29; risk ratio, 13.0; 95% CI, 1.82-93.01) and fat mass (MD, -3.15; 95% CI, -6.68 to 0.38), and no differences were observed between groups regarding abdominal circumference and body mass index. When compared with aerobic exercises, resistance training may result in a reduction of hot flash frequency (7/18 vs 14/18; risk ratio, 0.50; 95% CI, 0.27-0.94) and fat mass (MD, -7.80; 95% CI, -14.02 to -1.58) and no difference in the quality of life and body mass index. Regarding safety, no serious adverse events were reported. Based on the GRADE approach, the certainty of this evidence was graded as very low to low, leading to imprecisely estimated effects.

CONCLUSIONS AND RELEVANCE

Resistance muscle training seems to improve postmenopausal symptoms and functional capacity. Given the low to very low certainty of the evidence, further randomized clinical trials with higher methodological quality and better reports are still needed. As an implication for clinical practice, health professionals should consider individualized aspects such as the previous history of exercise practice, physical capacity, and adaptation period.

The effect and safety of Tai Chi on bone health in postmenopausal women: A meta-analysis and trial sequential analysis

Background

Tai Chi may be a promising exercise to prevent and control bone loss in postmenopausal women. This meta-analysis and trial sequential analysis aimed to evaluate the effect and safety of Tai Chi on bone health in postmenopausal women.

Method

Seven databases were searched from their inceptions to 11 May 2022 to collect randomized controlled trials (RCTs) investigating the effect and safety of Tai Chi on bone health in postmenopausal women. Two independent reviewers identified the eligible studies, extracted data, and assessed the risk of bias of included studies using the revised Cochrane risk-of-bias tool for randomized trials. The primary outcome was the bone mineral density (BMD), and secondary outcomes included bone turnover markers and calcaneus quantitative ultrasound. Subgroup analyses were conducted based on the duration of Tai Chi. Sensitivity analyses and publication bias assessment were performed. RevMan software (version 5.4.1) and R software (version 3.6.1) were used for data synthesis. The certainty of evidence was rated with the Grading of recommendations assessment, development, and evaluation (GRADE) system. We also performed the trial sequential analysis to evaluate the reliability of the evidence.

Results

A total of 25 reports involving 24 studies were included. Four studies were considered as high overall risk of bias, and the rest were some concerns. Among included studies, there were three comparisons including Tai Chi vs. non-intervention, Tai Chi vs. other exercises, and Tai Chi plus nutraceutical vs. nutraceutical. Compared with non-intervention, Tai Chi was more effective to improve BMD of lumbar spine (MD = 0.04, 95% CI 0.02 to 0.07, I2 = 0%, low certainty), femoral neck (MD = 0.04, 95% CI 0.02 to 0.06, I2 = 0%, low certainty), and trochanter (MD = 0.02, 95% CI 0.00 to 0.03, I2 = 0%, very low certainty), but there was no significant difference in increasing the BMD of Ward's triangle (MD = 0.02, 95% CI −0.01 to 0.04, I2 = 0%, very low certainty). Trial sequential analysis showed that the effect of Tai Chi vs. non-intervention on the BMD of lumbar spine and femoral neck was reliable, but the effect on the BMD of trochanter and Ward's triangle needed further verification. The subgroup analyses suggested that Tai Chi training for over 6 months had greater improvement in BMD of the lumbar spine, femoral neck, and trochanter than non-intervention. No significant differences were observed in the above outcomes of Tai Chi vs. other exercises, and Tai Chi plus nutraceutical vs. nutraceutical. There was insufficient evidence to support the effect of Tai Chi on bone turnover markers and calcaneus quantitative ultrasound. Few Tai Chi relevant adverse events occurred.

Conclusion

Tai Chi may be an optional and safe exercise for improving BMD loss in postmenopausal women, and practicing Tai Chi for more than 6 months may yield greater benefits. However, more rigorously designed RCTs are required to verify the benefits and to explore the optimal protocol of Tai Chi exercise for bone health.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=309148, identifier: CRD42022309148.

Exercise for osteoporosis: A literature review of pathology and mechanism

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

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Purpose

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

Methods

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

Results

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

Conclusions

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

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

Supplementary Information

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

Effects of water-based exercises on functioning of postmenopausal women: A systematic review with meta-analysis

OBJECTIVE

The aim of the present study was to compare the efficacy of Water-Based Exercise (WBE) versus Land-Based Exercise (LBE) and of WBE versus Non-Exercise in postmenopausal women on muscle strength, agility, flexibility, bone mineral density and aerobic capacity.

METHODS

We systematically searched in MEDLINE, PEDro, SciELO and the Cochrane Library RCT published until May 2022. Only randomized controlled trials were included. We analyzed the pooled results using weighted mean differences, standardized mean difference, and 95%CI were calculated.

RESULTS

Twenty studies met the inclusion criteria; although, sixteen studies were included in the meta-analyses. The studies presented low methodological quality. WBE was more effective than NE for improving muscle strength of knee extension (3.34), knee flexion (2.51), arm curl (6.78 repetitions), VO2Max (4.12 ml/kg), and flexibility (6.38 cm) When comparing WBE with LBE, no significant statistical difference was found regarding muscular strength of lower limbs (1.00), muscular strength of upper limbs (0.47), flexibility (1.95 cm), aerobic capacity (0.82 ml/kg) and lumbar bone mineral density (0.04 g/cm²).

CONCLUSIONS

WBE promotes significant benefits in muscle strength, aerobic capacity, and flexibility, when compared to no intervention. However, WBE was similar to the LBE for improving muscle strength, aerobic capacity, flexibility, agility, and bone mineral density - lumbar in postmenopausal women.

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

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

Effect of exercise on bone mineral density among patients with osteoporosis and osteopenia: A systematic review and network meta-analysis

AIMS AND OBJECTIVES

To systematically review and compare the efficacy of different exercise interventions on bone mineral density (BMD, g/cm² ) in patients with osteoporosis and osteopenia.

BACKGROUND

It is vitally important to prevent and treat bone loss in patients with osteoporosis and osteopenia. Exercise can effectively increase bone density and slow down bone loss in middle-aged and older people. However, it is still unclear which type of exercise intervention is the most effective on bone mineral density.

DESIGN

Systematic review and network meta-analysis (NMA) according to PRISMA.

METHODS

Randomised controlled trials of different exercise treatments for osteopenia and primary osteoporosis were included. A Frequentist network meta-analysis was conducted to appraise the efficacy of different types of exercise. The outcome was bone mineral density of different parts of the body.

RESULTS

Ninety-seven studies were included. The network meta-analysis showed that combined exercise, resistance exercise, aerobic exercise and mind-body exercise had a significant effect in improving the bone density of lumbar spine. The surface under the cumulative ranking area (SUCRA) values for mind-body exercise was 0.99 and ranked first. For BMD of the femoral neck, all kinds of exercise interventions increased the bone density significantly compared with no exercise and the optimal type was mind-body exercise (SUCRA = 0.99). In terms of the total hip bone mineral density, aerobic exercise and resistance exercise could improve hip bone density, with the resistance exercise (SUCRA = 0.95) ranking as first.

CONCLUSIONS

This NMA demonstrated the mind-body exercise might be the optimal exercise type to increase the BMD of the lumbar spine and femoral neck and resistance exercise is the most promising type for total hip BMD.

Effectiveness of Whole-Body Vibration Training to Improve Muscle Strength and Physical Performance in Older Adults: Prospective, Single-Blinded, Randomized Controlled Trial

Whole-body vibration training (WBVT) is emerging as an alternative exercise method that be easily performed by older adults. This clinical trial investigates the efficacy of WBVT in improving muscle strength and physical performance before resistance exercise, in comparison to conventional resistance exercise after stretching exercise in older adults. The WBVT group (n = 20) performed WBVT using a vibrating platform (SW-VC15™), followed by strengthening exercises. The control group (n = 20) performed stretching instead of WBVT. Both groups underwent a total of 12 sessions (50 min per session). The primary outcome was isokinetic dynamometer. The secondary outcomes were grip strength, short physical performance battery (SPPB), a 36-Item Short Form Survey (SF-36), and body composition analysis. In all results, only the time effect was significant, and the group effect or time x group effect was not. Both groups showed a significant increase in isokinetic dynamometer. Although there was no significant group effect, the increase in mean peak torque was greater in the WBVT group. The only WBVT group showed significant improvement in SPPB. In SF-36, only the control group showed significant improvements. WBVT can be safely performed by older adults and may be an alternative exercise method to boost the effect of strengthening exercise.

Determinants of estimated failure load in the distal radius after stroke: An HR-pQCT study

Bone health is often compromised after stroke and the distal radius is a common site of fragility fractures. The macro- and mircoproperties of bone tissue after stroke and their clinical correlates are understudied. The objectives of the study were to use High-Resolution peripheral Quantitative Computed Tomography (HR-pQCT) to investigate the bone properties at the distal radius, and to identify the correlates of estimated failure load for the distal radius in people with chronic stroke. This was a cross-sectional study of 64 people with stroke (age: 60.8 ± 7.7 years, stroke duration: 5.7 ± 3.9 years) and 64 age- and sex-matched controls. Bilateral bone structural, densitometric, geometric and strength parameters of the distal radius were measured using HR-pQCT. The architecture, stiffness and echo intensity of the bilateral biceps brachii muscle and brachial artery blood flow were evaluated using diagnostic ultrasound. Other outcomes included the Fugl-Meyer Motor Assessment (FMA), Motor Activity Log (MAL), and Composite Spasticity Scale (CSS). The results revealed a significant side (paretic vs non-paretic for the stroke group, non-dominant vs dominant for controls) by group (stroke vs control) interaction effect for estimated failure load, cortical area, cortical thickness, trabecular number and trabecular separation, and all volumetric density parameters. Post-hoc analysis showed percent side-to-side differences in bone outcomes were greater in the stroke group than the control group, with the exception of trabecular thickness and intracortical porosity. Among the HR-pQCT variables, percent side-to-side difference in trabecular volumetric bone mineral density contributed the most to the percent side-to-side difference in estimated failure load in the stroke group (R² change = 0.334, β = 1.106). Stroke-related impairments (FMA, MAL, CSS) were found to be significant determinants of the percent side-to-side difference in estimated failure load (R² change = 0.233, β = -0.480). This was the first study to examine bone microstructure post-stroke. We found that the paretic distal radius had compromised bone structural properties and lower estimated failure load compared to the non-paretic side. Motor impairment was a determinant of estimated bone strength at the distal radius and may be a potential intervention target for improving bone health post-stroke.

Oxidative balance score and risk of osteoporosis among postmenopausal Iranian women

To our knowledge, this is the first study to examine the association of oxidative balance score (OBS) and risk of osteoporosis. Findings suggest that a predominance of anti- over pro-oxidant exposures, as reflected by a higher OBS, is associated with lower risk of lumbar spine osteoporosis among postmenopausal Iranian women.

PURPOSE

The oxidative balance score (OBS) is a combined measure of pro- and anti-oxidant exposure status, with a higher OBS indicating a predominance of anti- over pro-oxidant exposures. We aimed to examine the potential association of OBS and risk of osteoporosis among postmenopausal Iranian women, hypothesizing that a higher OBS is associated with lower risk of postmenopausal osteoporosis.

METHODS

This cross-sectional study was conducted among 151 postmenopausal Iranian women aged 50-85 y. Bone mineral density (BMD) at lumbar spine and femoral neck was measured by dual-energy X-ray absorptiometry, and osteoporosis was defined using the WHO criteria as a BMD T-score of ≤ - 2.5 standard deviations. The OBS was calculated by combining information from 17 a-priori selected pro- and anti-oxidant components classified in the following four categories: non-dietary pro-oxidants (i.e., obesity and smoking); non-dietary anti-oxidants (i.e., physical activity); dietary pro-oxidants (i.e., saturated fatty acid, poly-unsaturated fatty acid, and iron); and dietary anti-oxidants (i.e., fiber, vitamin E, folate, vitamin C, alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin, lycopene, zinc, and selenium).

RESULTS

After controlling for several potential covariates in the multivariable-adjusted binary logistic regression analysis, subjects in the highest tertile of OBS had a lower risk of lumbar spine osteoporosis than those in the lowest tertile (odds ratio = 0.14; 95% confidence interval, 0.04-0.45; p = 0.001). The OBS was not associated with risk of femoral neck osteoporosis.

CONCLUSION

Findings suggest that a predominance of anti- over pro-oxidant exposures, as indicated by a higher OBS, is associated with lower risk of lumbar spine osteoporosis among postmenopausal Iranian women.

The effect of exercise training on osteocalcin, adipocytokines, and insulin resistance: a systematic review and meta-analysis of randomized controlled trials

Recently, it has been reported that osteocalcin (OC), in particular its undercarboxylated (ucOC) form, is not only a bone remodeling marker but also an active hormone that intercedes glucose metabolism in humans. This study aimed to determine the impact of an exercise intervention on ucOC, adiponectin, leptin, and insulin resistance (measured by HOMA-IR). PubMed, CINAHL, Medline, Google Scholar, and Scopus databases and reference lists of included studies were searched. Twenty-two randomized controlled trials (RCTs) of exercise training impact in adults were included in the analysis. Results showed an overall significant increase in serum ucOC (MD: 0.15 ng/ml; 95% CI: 0.05 to 0.25) and adiponectin (MD: 2.83 mg/ml; 95% CI: 1.67 to 3.98), a significant decline in leptin (MD: - 4.89 pg/ml; 95% CI: - 6.94 to - 2.84), fasting glucose (MD: - 2.29 mg/dl; 95% CI: - 4.04 to - 0.54), fasting insulin (MD, - 8.90 μIU/ml; 95% CI: - 13.81 to - 3.98), and HOMA-IR (MD: - 1.96; 95% CI: - 3.11 to - 0.80). However, after removal of studies that had prescribed a balanced diet along with exercise intervention, total OC (TOC) levels also increased in the exercise group compared with the control group (MD: 0.36 ng/ml; 95% CI: 0.07 to 0.65). Our findings demonstrate that exercise-induced increases in ucOC are the probable cause of increased adiponectin. Additionally, increases in ucOC itself are probably due to changes in leptin levels and other factors, rather than its direct impact on bone and its osteoblastic activity. Further studies are required to clarify the mechanisms underlying the impact of exercise training on ucOC, adipocytokines, and insulin resistance.

The effect of exercise intensity on bone in postmenopausal women (part 2): A meta-analysis

BACKGROUND

Previous reviews have concluded that exercise has only modest effects on bone mineral density (BMD) in postmenopausal women. Despite the well-recognized strong positive relationship between load magnitude and bone response observed from animal research, the majority of human trials have examined the effects of only low to moderate intensity exercise on bone. We speculated that meta-analysing according to intensity may reveal a more potent exercise effect at higher intensity.

OBJECTIVES

To determine the effects of low, moderate and high intensity exercise on BMD at the spine and hip in postmenopausal women.

METHODS

Electronic databases and reference lists were searched for RCTs that examined the effect of exercise compared to control on DXA-derived lumbar spine, femoral neck or total hip BMD in healthy postmenopausal women. Interventions were classified as low, moderate or high intensity and pooled based on classification. Mean differences (MD) were calculated using random effects models and a risk of bias analysis was undertaken. To determine the effect of different exercise types (resistance and impact training) on BMD outcomes, subgroup analyses for all intensity categories and outcomes were conducted. Separate meta-analyses were undertaken to examine the influence of adding exercise to a bone medication intervention and to examine exercise effects on fracture risk.

RESULTS

Fifty-three trials, testing 63 interventions (19 low, 40 moderate, 4 high intensity) were included. At the lumbar spine, high intensity exercise yielded greater BMD effects (MD = 0.031 g/cm² 95% CI [0.012, 0.049], p = 0.002) than moderate (MD = 0.012 g/cm² 95% CI [0.008, 0.017], p < 0.001) and low intensity (MD = 0.010 g/cm² 95% CI [0.005, 0.015], p < 0.001). Low and moderate intensity exercise was equally effective at the femoral neck (low: 0.011 g/cm² 95% CI [0.006, 0.016], p < 0.001; moderate: 0.011 g/cm² 95% CI [0.007, 0.015], p < 0.001), but no effect of high-intensity exercise was observed. Moderate intensity exercise increased total hip BMD (0.008 g/cm² 95% CI [0.004, 0.012], p < 0.001), but low intensity did not. There were insufficient data to meta-analyse the effect of high intensity exercise at the total hip. Resistance training, potentially in combination with impact training, appears to be the most effective osteogenic stimulus at the spine and hip. Findings from meta-regression analyses were not informative and no influence of exercise on medication efficacy was observed. Risk of bias was mainly low or unclear due to insufficient information reported.

CONCLUSION

High intensity exercise is a more effective stimulus for lumbar spine BMD than low or moderate intensity, but not femoral neck BMD, however, the latter finding may be due to lack of power. While data from high-intensity exercise interventions are limited, the current comprehensive meta-analysis demonstrates the same positive relationship between load magnitude and bone response in humans that is observed in animal research. Findings have implications for optimal exercise prescription for osteoporosis in postmenopausal women.

STUDY REGISTRATION

Registered on PROSPERO (CRD42018117254).

The effect of exercise intensity on bone in postmenopausal women (part 1): A systematic review

BACKGROUND

Previous systematic reviews and meta-analyses of exercise effects on bone have reported null or modest effect sizes. While animal research has determined that a strong positive relationship exists between load magnitude/intensity and bone adaptation, nevertheless many human exercise interventions have been applied at low intensity. Meta-analytic pooling of exercise interventions irrespective of intensity dilutes the ability to detect efficacy of any one training regimen. Parsing out efficacy of low, moderate and high intensity exercise interventions will assist the determination of optimal exercise prescription for bone.

OBJECTIVES

First, to summarise and critically evaluate existing evidence of exercise effect on bone mass, bone structure and bone turnover markers (BTMs) in healthy postmenopausal women. Second, to examine the influence of intensity on bone response to exercise.

METHODS

Electronic databases (Embase, Scopus, CINAHL Plus, SPORTDiscus), database platforms (PubMed, Cochrane CENTRAL, ProQuest Central, Web of Science) and reference lists of included studies were searched for controlled trials and randomised controlled trials that described the effect of any exercise intervention compared to control on bone mass, bone structure or BTMs in healthy postmenopausal women. Fracture incidence was included as an exploratory endpoint. Data was extracted and weighed against the results of a comprehensive risk of bias analysis.

RESULTS

One hundred trials were included, investigating a total of 120 exercise interventions. Of those, 57 interventions were low intensity, 57 were moderate, and six were high intensity. On balance, low intensity exercise was not an effective stimulus to increase bone mass. Higher quality evidence suggests moderate to high intensity interventions, particularly those that combined high intensity resistance and impact training, were most beneficial for bone mass. Only high intensity exercise appears to improve structural parameters of bone strength, however, data are limited. Only low and moderate intensity interventions have measured BTMs and no notable benefits have been observed. The quality of trials varied greatly, and risk of bias determinations were frequently limited by insufficiently reported detail.

CONCLUSION

Heterogeneity in both study quality and outcomes limits the ability to draw strong conclusions from this comprehensive systematic review of RCT and CT reports. Nevertheless, there is a tendency in the higher quality data to indicate exercise intensity is positively related to the adaptive bone response. Part 2 of this review series reports a meta-analysis of the RCT data in order to draw quantitative conclusions from the higher quality trials.

STUDY REGISTRATION

Registered on PROSPERO (CRD42018117254).

Effects of 6-Month Multimodal Physical Exercise Program on Bone Mineral Density, Fall Risk, Balance, and Gait in Patients with Alzheimer's Disease: A Controlled Clinical Trial

We aimed to determine the short- and medium-term effects of a multimodal physical exercise program (MPEP) on bone health status, fall risk, balance, and gait in patients with Alzheimer’s disease. A single-blinded, controlled clinical trial was performed where 72 subjects were allocated in a 3:1 ratio to an intervention group (IG; n = 53) and control group (CG; n = 19), where the IG’s subjects were admitted to live in a State Reference Center of Alzheimer’s disease, which offers the targeted exercise program, while the CG’s subjects resided in independent living. A multidisciplinary health team assessed all patients before allocation, and dependent outcomes were again assessed at one, three, and six months. During the study, falls were recorded, and in all evaluations, bone mineral density was measured using a calcaneal quantitative ultrasound densitometer; balance and gait were measured using the performance-oriented mobility assessment (POMA), the timed up and go test (TUG), the one-leg balance test (OLB), and the functional reach test (FR). There were no differences between groups at baseline for all outcome measures. The prevalence of falls was significantly lower in the IG (15.09%) than in the CG (42.11%) (χ² = 5.904; p = 0.015). We also found that there was a significant time*group interaction, with a post hoc Šidák test finding significant differences of improved physical function, especially in gait, for the IG, as assessed by POMA-Total, POMA-Gait, and TUG with a large effect size (ƞ²p = 0.185–0.201). In balance, we found significant differences between groups, regardless of time, and a medium effect size as assessed by POMA-Balance and the OLB (ƞ²p = 0.091–0.104). Clinically relevant effects were observed, although without significant differences in bone health, with a slowing of bone loss. These results show that a multimodal physical exercise program reduces fall risk and produces an improvement in gait, balance, and bone mineral density in the short and medium term in institutionalized patients with Alzheimer’s disease.

Effects of Different Types of Exercise on Bone Mineral Density in Postmenopausal Women: A Systematic Review and Meta-analysis

In this sub-analysis of a comprehensive meta-analysis, we aimed to determine the effect of different types of exercise on (areal) bone mineral density (BMD) in postmenopausal women. A systematic review of the literature according to the PRISMA statement included (a) controlled trials, (b) with at least one exercise and one control group, (c) intervention ≥ 6 months, (d) BMD assessments at lumbar spine (LS), femoral neck (FN) or total hip (TH), (e) in postmenopausal women. Eight electronic databases were scanned without language restrictions up to March 2019. The present subgroup analysis was conducted as a mixed-effect meta-analysis with "type of exercise" as the moderator. The 84 eligible exercise groups were classified into (a) weight bearing (WB, n = 30) exercise, (b) (dynamic) resistance exercise (DRT, n = 18), (c) mixed WB&DRT interventions (n = 36). Outcome measures were standardized mean differences (SMD) for BMD-changes at LS, FN and TH. All types of exercise significantly affect BMD at LS, FN and TH. SMD for LS average 0.40 (95% CI 0.15-0.65) for DRT, SMD 0.26 (0.03-0.49) for WB and SMD 0.42 (0.23-0.61) for WB&DRT. SMD for FN were 0.27 (0.09-0.45) for DRT, 0.37 (0.12-0.62) for WB and 0.35 (0.19-0.51) for WB&DRT. Lastly, SMD for TH changes were 0.51 (0.28-0.74) for DRT, 0.40 (0.21-0.58) for WB and 0.34 (0.14-0.53) for WB&DRT. In summary, we provided further evidence for the favorable effect of exercise on BMD largely independent of the type of exercise. However, in order to generate dedicated exercise recommendations or exercise guideline, meta-analyses might be a too rough tool.