Exercise, muscle, and the applied load-bone strength balance

Rehabilitative good clinical practice in the treatment of osteoporosis: a comprehensive review of clinical evidences

PURPOSE

Clinical practice guidelines (CPGs) are essential for guiding rehabilitation interventions. However, CPGs specifically addressing rehabilitation for osteoporosis patients remain scarce in the literature. This review aims to present, compare, and summarize recent guidelines and evidence, highlighting best practices in osteoporosis rehabilitation management.

MATERIALS AND METHODS

A total of 19 guidelines were identified following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Three independent appraisers assessed the quality of each CPG using the Appraisal of Guidelines for Research and Evaluation version II (AGREE II) instrument. Standardized domain and overall quality scores were calculated, and intraclass correlation coefficients (ICCs) were used to assess the level of agreement among the appraisers.

RESULTS

Agreement among appraisers for AGREE II scores ranged from moderate to very good (ICC = 0.60 to 0.90). The quality of the included CPGs varied significantly, with AGREE sub-scores ranging from 48.25% to 75.73%. The Level of Evidence (LoE) and Grade of Recommendation (GoR) differed across the guidelines included in this review. Information on exercise types, intensity, frequency, duration, and contraindications were inconsistent among CPGs.

CONCLUSIONS

Recommendations regarding exercise parameters were often vague and inconsistent between CPGs, necessitating critical evaluation by healthcare providers when making clinical decisions.

Cellulose acetate/silica composites: Physicochemical and biological characterization

Cellulose acetate is of remarkable scientific interest, becoming more useful when is used in obtaining of the composite materials containing nanoparticles, as result of its improved properties. Thus, cellulose acetate/silica composite films obtained by casting the solutions of cellulose acetate (CA)/tetraethyl orthosilicate (TEOS) in different mixing ratios were analyzed in this paper. The impact of TEOS addition, and implicitly of the silica nanoparticles on the mechanical strength, water vapor sorption properties and antimicrobial activity of the cellulose acetate/silica films were mainly monitored. The results of the tensile strength tests were discussed in correlation with data obtained from Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. It was found that samples with low TEOS content show improved mechanical strength compared to samples with high amounts of TEOS. The microstructural characteristics of the studied films affect their moisture sorption capacity so that the weight of the adsorbed water increases with the addition of TEOS. These features are complemented with the antimicrobial activity against Staphylococcus aureus and Escherichia coli bacterial species. The obtained data show that the cellulose acetate/silica films, and especially those with low silica content have improved properties that can recommend them for applications in the biomedical field.

Effects of 8-week High-Intensity Interval Training and Moderate-Intensity Continuous Training on Bone Metabolism in Sedentary Young Females

Objective

High-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) have been reported as effective exercise modes on bone metabolism. However, very few studies focused on young women with sedentary behavior. The purpose of this study was to investigate the effects of 8-week HIIT on bone metabolism in sedentary young women.

Methods

26 healthy, sedentary female participants were randomly assigned to either the HIIT (n = 13, age 23.2 ± 2.9 yr, weight 59.2 ± 7.2 kg, height 162.9 ± 3.3 cm, body mass index 22.3 ± 2.7 kg/m²) or MICT (n = 13, age 21.9 ± 1.7 yr, weight 59.3 ± 6.6 kg, height 160.9 ± 4.4 cm, body mass index 21.6 ± 2.4 kg/m²) group. Both groups completed 8 weeks (3 sessions/week) of training on the treadmill, where the HIIT group were asked to complete 6 × 3-min bouts of running at the intensity of 80–90% maximum oxygen uptake (VO_2max) separated by 2-min active recovery at 30–40% VO_2max and the MICT group completed 30-min continuous running at the intensity of 60–70% VO_2max. The body composition, bone mineral density (BMD), calcaneus quantitative ultrasound, bone turnover markers, and lower limb muscle strength were measured pre and post interventions.

Results

After 8-week interventions, 1) The total body BMD (HIIT, +8.5%; MICT, +5.5%) significantly increased (p < 0.05) without difference between the two groups (p > 0.05). The calcaneus broadband ultrasound attenuation (CBUA) (HIIT, +16.0%; MICT, +4.6%) and calcaneus stiffness index (CSI) (HIIT, +16.7%; MICT, +2.5%) significantly increased in HIIT group (p < 0.05), but not in MICT group (p > 0.05). 2) The 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) (HIIT, +42.8%; MICT, +24.9%) level increased in both groups with significantly higher changes in HIIT (p < 0.05). 3) The score of standing long jump (HIIT, +10.3%; MICT, +3.8%) and vertical jump (HIIT, +5.3%; MICT, +2.0%) increased in both groups with significantly higher changes in HIIT (p < 0.05).

Conclusions

It suggested that 8-week HIIT and MICT interventions could improve bone metabolism. Compared with a similar workload of MICT, HIIT elicited superior benefits on bone metabolism.

The Effects of Tetrapeptides Designed to Fit the Androgen Binding Site of ZIP9 on Myogenic and Osteogenic Cells

Simple Summary

Pro-androgenic substances such as testosterone are often used to treat muscle- or bone-related disorders. Their interactions with the classical androgen receptor, however, can trigger a number of undesirable effects. It would therefore be of great benefit if the positive androgenic effects could be obtained by circumventing the classical androgen receptor. ZIP9 is a recently identified membrane-bound androgen receptor of physiological significance. Using in silico methods, we identified and verified the extracellular localization of its androgen binding site and designed small peptides that fit in it that do not interact with the AR. All peptides were found to be pro-androgenic; they stimulate mineralization in osteoblastic cells and myogenesis in myoblasts. Thus, these peptides might serve as testosterone surrogates in the treatment of osteogenic or myogenic disorders.

Abstract

ZIP9 is a recently identified membrane-bound androgen receptor of physiological significance that may mediate certain physiological responses to androgens. Using in silico methods, six tetrapeptides with the best docking properties at the testosterone binding site of ZIP9 were synthesized and further investigated. All tetrapeptides displaced T-BSA-FITC, a membrane-impermeable testosterone analog, from the surface of mouse myogenic L6 cells that express ZIP9 but not the classical androgen receptor (AR). Silencing the expression of ZIP9 with siRNA prevented this labeling. All tetrapeptides were found to be pro-androgenic; in L6 cells they stimulated the expression of myogenin, triggered activation of focal adhesion kinase, and prompted the fusion of L6 myocytes to syncytial myotubes. In human osteoblastic SAOS-2 cells that express AR and ZIP9, they reduced the expression of alkaline phosphatase and stimulated mineralization. These latter effects were prevented by silencing ZIP9 expression, indicating that the osteoblast/osteocyte conversion is exclusively mediated through ZIP9. Our results demonstrate that the synthetic tetrapeptides, by acting as ZIP9-specific androgens, have the potential to replace testosterone or testosterone analogs in the treatment of bone- or muscle-related disorders by circumventing the undesirable effects mediated through the classical AR.

The effect of impact exercise on bone mineral density: A longitudinal study on non-athlete adolescents

PURPOSE

High impact exercise is known to induce osteogenic effects in the skeleton. However, less is known about the systemic effect of exercise practice in a potential adaptive mechanism of the skeletal accrual. This research aimed to assess the effect of impact exercise on bone mineral density (BMD) in the radius throughout adolescence.

METHODS

This study evaluated 1137 adolescents, at 13 and 17 years old, as part of the population-based cohort EPITeen. BMD (g/cm²) was measured at the ultradistal and proximal radius of the non-dominant forearm by dual-energy X-ray absorptiometry (DXA) using a Lunar® Peripheral Instantaneous X-ray Image device. The practice of (extra-curricular) exercise was categorized as: no exercise, exercise with high impact and exercise with low impact. Regression coefficients (β) and respective 95% confidence intervals (CI_95%) were used to estimate the association between exercise practice categories at 13 years old and BMD at 13 and 17 years old and BMD gain between evaluations.

RESULTS

In boys, at 13 years, BMD was similar between the ones not practicing exercise and those practicing exercise with low impact, and the gain of BMD was also similar in both groups. Still in boys, at 13 years, those who practiced exercise with high impact presented higher mean (standard-deviation) of BMD, comparing to the other two groups (no exercise and low impact exercise), and also significantly increased the BMD gain between 13 and 17 years (β = 0.013; CI_95%0.003;0.023). In girls, no statistically significant differences on BMD were found between the categories of exercise at 13 years and BMD at 17 years of age.

CONCLUSION

This research shows that the practice of high impact exercise could help to increase BMD more than low impact exercise even in a nonweight-bearing bone during adolescence.

Swimming as Treatment for Osteoporosis: A Systematic Review and Meta-analysis

Osteoporosis is a chronic disease that seriously affects human health and quality of life. This study is aimed at determining whether swimming had an effect on the bone mineral density (BMD) of the spine and femoral neck in postmenopausal and premenopausal osteoporosis patients. We retrieved relevant literature and analyzed data from randomized controlled trials to assess the effect of swimming on BMD in postmenopausal and premenopausal women. Relevant studies, with no language restrictions, from inception to September 2019, were retrieved from the PubMed, Cochrane, EMBASE, and EBSCO databases independently by two investigators. The keywords used for the literature search were “osteoporosis” and “swimming.” The main results included BMD and T-score. We searched 256 relevant articles and finally screened five articles, including 263 participants. Lumbar spine density was mentioned in three articles. Although the heterogeneity of lumbar vertebral density is moderate, the analysis of swimmers to nonswimmers shows that the lumbar vertebral density in swimmers is improved [heterogeneity: chi² = 5.16, df = 2 (P = 0.08); I² = 61%]. We analyzed the following heterogeneous subgroups: subgroup 1 (3–6 hours) and subgroup 2 (<3 hours). The BMD in subgroup 1 was significantly higher than that in the placebo, while no effect on BMD was found in subgroup 2 [heterogeneity: chi² = 0.15, df = 3 (P = 0.70); I² = 0%]. According to the current evidence, swimming may improve the BMD of postmenopausal women participants, if the swimming time is between 3 and 6 hours, especially in long-term swimmers. However, the effectiveness of swimming does require further investigation.

Algorithm for the management of patients at low, high and very high risk of osteoporotic fractures

Guidance is provided in an international setting on the assessment and specific treatment of postmenopausal women at low, high and very high risk of fragility fractures.

INTRODUCTION

The International Osteoporosis Foundation and European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis published guidance for the diagnosis and management of osteoporosis in 2019. This manuscript seeks to apply this in an international setting, taking additional account of further categorisation of increased risk of fracture, which may inform choice of therapeutic approach.

METHODS

Clinical perspective and updated literature search.

RESULTS

The following areas are reviewed: categorisation of fracture risk and general pharmacological management of osteoporosis.

CONCLUSIONS

A platform is provided on which specific guidelines can be developed for national use to characterise fracture risk and direct interventions.

The Health Benefits of Exercise in Overweight and Obese Patients

More than 30% of U.S. adults are obese or overweight. A program of regular physical activity is recommended as part of an effective lifestyle intervention for weight loss and weight management. However, more than 40% of adults do not engage in sufficient physical activity to realize these beneficial effects on body weight. Physicians may encounter many barriers to counseling physical activity, such as lack of knowledge or self-efficacy for counseling patients about physical activity. Obese individuals may be reluctant to exercise because of weight stigma, physique anxiety, and other factors; therefore, referral to a weight management specialist or clinical exercise physiologist can be helpful in facilitating exercise and assisting in achieving a clinically meaningful weight loss. Exercise has many benefits on physical and mental health and well-being that go well beyond weight loss, and it is for these reasons that exercise is particularly important for overweight and obese individuals.

A cross-sectional and 6-year follow-up study of associations between leisure time physical activity and vertebral fracture in adults

Introduction

Vertebral fractures are common osteoporotic fractures, affecting 2–46% of the population, causing morbidity and increased risk of mortality. Physical activity has beneficial effects for bone health, including increased bone mineral density and reduced hip fractures. However, evidence concerning prevention of vertebral fractures is scarce. Therefore, the aim of this study was to investigate the association between leisure time physical activity and vertebral fracture risk.

Methods

The data were retrieved from the 2001 and 2007–2008 surveys of the Tromsø Study, a longitudinal population study in Norway. A total of 1904 participants (1030 women and 874 men, age 38–87 yr and 40–87 yr respectively) were included in the cross-sectional analysis (2007–2008). Prospective follow-up data (2001 to 2007) on physical activity were available for 1131 participants (636 women and 495 men, age 32–69 yr and 33–69 yr respectively). Physical activity was assessed by a questionnaire and vertebral fracture by lateral vertebral fracture assessment from dual-energy x-ray absorptiometry scans. Logistic regression was used to examine associations between physical activity and vertebral fracture.

Results

After controlling for confounders (age, height, weight, smoking, osteoporosis, osteoporosis medication, left hip total bone mineral density, and use of hormones in women only), no cross-sectional associations between physical activity levels and vertebral fracture were observed, OR 1.13 (95% CI: 0.59–2.13), for moderately active women and 1.44 (0.61–3.42) for highly active women, compared with sedentary women. In men, the respective ORs were 1.74 (95% CI: 0.91–3.35) and 1.64 (0.78–3.41). In the prospective analyses, OR for vertebral fracture in women with reduced physical activity was 0.81 (95% CI: 0.18–3.62), 1.24 (95% CI: 0.29–5.26) for increased physical activity and 1.54 (95% CI: 0.43–5.50) for active unchanged physical activity pattern, compared with sedentary unchanged physical activity. In men, the respective ORs were 2.05 (95% CI: 0.57–7.42), 2.23 (95% CI: 0.63–7.87), and 1.81 (95% CI: 0.54–6.02). Subanalyses of women and men ≥50 yr showed similar results.

Conclusions

Our findings suggest that physical activity does not play a major role in preventing vertebral fractures in Norwegian adults. Future studies may benefit from data on incident vertebral fracture, and objectively measured physical activity.

Intertrochanteric fracture with low-energy trauma in a young woman with anorexia nervosa: A case report

RATIONALE

Anorexia nervosa is a chronic psychiatric disease defined by severe weight loss, due to fear of obesity, and self-imposed semi-starvation. Of the many complications following anorexia nervosa, low bone mineral density (BMD) is a significant risk factor for fractures. Anorexia nervosa is associated with higher risk of incident fracture in females across all age groups, and in males >40 years old. Sites at highest risk of fracture include the hip/femur and pelvis in females, and vertebrae in males with anorexia nervosa.

PATIENT CONCERNS

A 29-year-old woman known to have suffered from anorexia nervosa 15 years ago visited the emergency department due to right hip pain after falling while getting out of a taxi. During the period of anorexia nervosa, she had a body mass index (BMI) of 14.06 kg/m (weight, 36 kg; height, 1.60 m) and suffered from amenorrhea. At the time of presentation, she had a BMI of 19.53 kg/m (weight, 50 kg; height, 1.60 m) and had regular menstrual periods, indicating clinical recovery from anorexia nervosa.

DIAGNOSES

Plain radiography, computed tomography, and bone scintigraphy revealed AO 31-A2.2 type right hip proximal femur intertrochanteric fracture. The BMD showed a T score of -3.9 in the hip and -3.6 at the lumbar level, indicating severe osteoporosis.

INTERVENTIONS

Osteosynthesis was performed with proximal femoral nail antirotation (PFNA) and wiring.

OUTCOMES

There were no specific symptoms, such as trauma or infection, during postoperative rehabilitation and postoperative management, and she was discharged after 2 weeks. After 1 year of follow-up at our outpatient clinic, she had no complications.

LESSONS

Here, we describe an unusual case of unilateral femoral intertrochanteric fracture that occurred after clinical recovery from anorexia nervosa. This case indicated that the risk of fracture remains even after recovery of BMI. We propose that women who have clinically recovered from anorexia nervosa should be advised to undergo annual osteodensitometric analyses after consulting with specialists in other areas (psychiatry, endocrinology, eating disorders).

Critical gaps in the medical knowledge base of eating disorders

Eating disorders are unique in that they inherently have much medical comorbidity both as a part of restricting-type eating disorders and those characterized by purging behaviors. Over the last three decades, remarkable progress has been made in the understanding and treatment of the medical complications of eating disorders. Yet, unfortunately, there is much research that is sorely needed to bridge the gap between current medical knowledge and more effective and evidence-based medical treatment knowledge. These gaps exist in many different clinical areas including cardiology, electrolytes, gastrointestinal and bone disease. In this paper, we discuss some of the knowledge gap areas, which if bridged would help develop more effective medical intervention for this population of patients.

Effect of a resistance and balance exercise programme for women with osteoporosis and vertebral fracture: study protocol for a randomized controlled trial

BACKGROUND

Osteoporotic vertebral fractures are common, and are associated with reduced functioning and health related quality of life. The primary aims of this randomized controlled trial are to examine the immediate and long-term effects of a 12-weeks supervised group exercise programme on habitual walking speed in older women with osteoporosis and a history of vertebral fracture. The secondary aims are to examine the immediate and long-term effects of the exercise program on physical fitness, fear of falling and quality of life.

METHODS

The study is a single-blinded randomized controlled trial. Women aged 65 years or older with osteoporosis and a history of vertebral fracture are included. The intervention group receives a 12-week multicomponent exercise programme, including resistance training combined with balance training. The control group receives usual care. Adherence to the programme will be of importance for the internal validity of the study. Participants in the exercise group who don't attend will be followed up with motivational phone calls. The primary outcome is habitual walking speed over 10 m. Secondary outcomes are health related quality of life (Qualeffo-41, SF-36), physical activity (I-PAQ), Patient Specific Functional Scale, Fear of falling (FES-1) and physical fitness (Senior Fitness test, Functional reach test, 4 square step test, grip strength). Sample size, based on the primary outcome, is 150 participants randomized into the two arms on a 1:1 allocation, including an estimated 20% drop out. Descriptive data will be reported as mean (standard deviation), median (range) or count (percent) as appropriate. The data will be analysed following the intention-to-treat principle. Between group differences in primary and secondary outcomes at 3 months follow-up will be assessed using linear regression models with respective outcome at baseline as covariate and the randomised group as factor.

DISCUSSION

This trial will generate new knowledge on the effects of a multicomponent exercise programme among women over 65 years with osteoporosis and a history of vertebral fracture, knowledge that is of importance for clinicians, health managers and policy makers.

TRIAL REGISTRATION

ClincialTrials.gov Identifier: NCT02781974 . Registered 18.05.16. Retrospectively registered.

Irisin in metabolic diseases

INTRODUCTION

Irisin is a myokine/adipokine induced by the exercise in mice and humans, which is proposed to induce "browning" of white adipose tissue, its primary target, thus increasing thermogenesis and energy expenditure. Since its identification, irisin has been linked to favorable effects on metabolic diseases, including obesity, type 2 diabetes mellitus (T2DM), lipid metabolism and cardiovascular disease (CVD), nonalcoholic fatty liver disease (NAFLD), polycystic ovary syndrome (PCOS), and metabolic bone diseases. Generally, despite the promising profile of irisin in rodents, its effects on human are less recognized.

REVIEW

Most, but not all studies show a positive association between irisin and indices of adiposity. In T2DM, NAFLD, and CVD, most observational studies reported lower irisin levels in patients than controls. Regarding metabolic bone diseases, irisin is positively associated with bone mineral density and strength in athletes, and inversely associated with osteoporotic fractures in postmenopausal osteoporosis. In PCOS, data remain largely conflicting. Irisin does not seem to be further reduced when two metabolic diseases, e.g., T2DM and NAFLD, or obesity and NAFLD exist though more data are needed. Furthermore, it seems that diverse confounders may have affected the results of different clinical studies.

CONCLUSION

Irisin remains an appealing molecule from a pathophysiological point of view and an appealing therapeutic target for metabolic diseases, albeit much research is still needed.

Assessment and clinical management of bone disease in adults with eating disorders: a review

AIM

To review current medical literature regarding the causes and clinical management options for low bone mineral density (BMD) in adult patients with eating disorders.

BACKGROUND

Low bone mineral density is a common complication of eating disorders with potentially lifelong debilitating consequences. Definitive, rigorous guidelines for screening, prevention and management are lacking. This article intends to provide a review of the literature to date and current options for prevention and treatment.

METHODS

Current, peer-reviewed literature was reviewed, interpreted and summarized.

CONCLUSION

Any patient with lower than average BMD should weight restore and in premenopausal females, spontaneous menses should resume. Adequate vitamin D and calcium supplementation is important. Weight-bearing exercise should be avoided unless cautiously monitored by a treatment team in the setting of weight restoration. If a patient has a Z-score less than expected for age with a high fracture risk or likelihood of ongoing BMD loss, physiologic transdermal estrogen plus oral progesterone, bisphosphonates (alendronate or risedronate) or teriparatide could be considered. Other agents, such as denosumab and testosterone in men, have not been tested in eating-disordered populations and should only be trialed on an empiric basis if there is a high clinical concern for fractures or worsening bone mineral density. A rigorous peer-based approach to establish guidelines for evaluation and management of low bone mineral density is needed in this neglected subspecialty of eating disorders.