Weight-bearing exercise and markers of bone turnover in female athletes

Does Swimming Exercise Impair Bone Health? A Systematic Review and Meta-Analysis Comparing the Evidence in Humans and Rodent Models

BACKGROUND

The effect of swimming on bone health remains unclear, namely due to discrepant findings between studies in humans and animal models.

OBJECTIVE

The aim of this systematic review and meta-analysis is to identify the available evidence on the effects of swimming on bone mass, geometry and microarchitecture at the lumbar spine, femur and tibia in both humans and rodent animal models.

METHODS

The study followed PRISMA guidelines and was registered at PROSPERO (CRD4202236347 and CRD42022363714 for human and animal studies). Two different systematic literature searches were conducted in PubMed, Scopus and Web of Science, retrieving 36 and 16 reports for humans and animal models, respectively.

RESULTS

In humans, areal bone mineral density (aBMD) was similar between swimmers and non-athletic controls at the lumbar spine, hip and femoral neck. Swimmers' tibia diaphysis showed a higher cross-sectional area but lower cortical thickness. Inconsistent findings at the femoral neck cortical thickness were found. Due to the small number of studies, trabecular microarchitecture in human swimmers was not assessed. In rodent models, aBMD was found to be lower at the tibia, but similar at the femur. Inconsistent findings in femur diaphysis cross-sectional area were observed. No differences in femur and tibia trabecular microarchitecture were found.

CONCLUSION

Swimming seems to affect bone health differently according to anatomical region. Studies in both humans and rodent models suggest that tibia cortical bone is negatively affected by swimming. There was no evidence of a negative effect of swimming on other bone regions, both in humans and animal models.

Serum levels of bone turnover markers including calculation of Z-scores: Data from a Dutch healthy reference cohort

Introduction

Bone turnover markers (BTM) are biochemical compounds reflecting different stages of bone metabolism. Their levels change with age and differ between males and females. This makes clinical interpretation and comparison more difficult. Therefore, our aim was to establish BTM reference values which can be used to calculate Z-scores for use in daily clinical practice.

Methods

Serum markers of collagen resorption, bone formation/regulation, collagen formation and bone mineralization (sCTX, OC, PINP and BALP, respectively) were measured in non-fasting volunteers without bone-related abnormalities. Raw data was plotted and gender-specific age cohorts were established with their respective means and standard deviations (SD). Z-scores can be calculated using these reference values to correct for the influence of age and gender on BTM.

Results

In total, 856 individuals were included of which 486 (57 %) were female. Individuals were aged between 7 and 70 years. Highest serum levels of BTM were found in childhood and puberty. Peak levels are higher in boys than girls and prevail at later ages. In adults, BTM levels decrease before reaching stable nadir levels. In adults, 10-year reference cohorts with means and SD were provided to calculate Z-scores.

Conclusion

With our data, Z-scores of sCTX, OC, PINP and BALP can be calculated using reference categories (for age and gender) of Caucasian healthy volunteers. Clinicians can use BTM Z-scores to determine whether there are changes in bone turnover physiology beyond those expected during aging. BTM Z-scores facilitate harmonization of data interpretation in daily clinical practice and research.

Relationship between Football-Specific Training Characteristics and Tibial Bone Adaptation in Male Academy Football Players

We examined the relationship between football-specific training and changes in bone structural properties across a 12-week period in 15 male football players aged 16 years (Mean ± 1 SD = 16.6 ± 0.3 years) that belonged to a professional football academy. Tibial scans were performed at 4%, 14% and 38% sites using peripheral quantitative computed tomography immediately before and 12 weeks after increased football-specific training. Training was analysed using GPS to quantify peak speed, average speed, total distance and high-speed distance. Analyses were conducted with bias-corrected and accelerated bootstrapped 95% confidence intervals (BCa 95% CI). There were increases in bone mass at the 4% (mean ∆ = 0.15 g, BCa 95% CI = 0.07, 0.26 g, g = 0.72), 14% (mean ∆ = 0.04 g, BCa 95% CI = 0.02, 0.06 g, g = 1.20), and 38% sites (mean ∆ = 0.03 g, BCa 95% CI = 0.01, 0.05 g, g = 0.61). There were increases in trabecular density (4%), (mean ∆ = 3.57 mg·cm^-3, BCa 95% CI = 0.38, 7.05 mg·cm^-3, g = 0.53), cortical dentsity (14%) (mean ∆ = 5.08 mg·cm^-3, BCa 95% CI = 0.19, 9.92 mg·cm^-3, g = 0.49), and cortical density (38%) (mean ∆ = 6.32 mg·cm^-3, BCa 95% CI = 4.31, 8.90 mg·cm^-3, g = 1.22). Polar stress strain index (mean ∆ = 50.56 mm³, BCa 95% CI = 10.52, 109.95 mm³, g = 0.41), cortical area (mean ∆ = 2.12 mm², BCa 95% CI = 0.09, 4.37 mm², g = 0.48) and thickness (mean ∆ = 0.06 mm, BCa 95% CI = 0.01, 0.13 mm, g = 0.45) increased at the 38% site. Correlations revealed positive relationships between total distance and increased cortical density (38%) (r = 0.39, BCa 95% CI = 0.02, 0.66), and between peak speed and increased trabecular density (4%) (r = 0.43, BCa 95% CI = 0.03, 0.73). There were negative correlations between total (r = -0.21, BCa 95% CI = -0.65, -0.12) and high-speed distance (r = -0.29, BCa 95% CI = -0.57, -0.24) with increased polar stress strain index (38%). Results suggest that despite football training relating to increases in bone characteristics in male academy footballers, the specific training variables promoting adaptation over a 12-week period may vary. Further studies conducted over a longer period are required to fully elucidate the time-course of how certain football-specific training characteristics influence bone structural properties.

Resistance Training for Patients with Cancer: A Conceptual Framework for Maximizing Strength, Power, Functional Mobility, and Body Composition to Optimize Health and Outcomes

There are many benefits to the addition of exercise to cancer treatment and survivorship, particularly with resistance training regimens that target hypertrophy, bone mineral density, strength, functional mobility, and body composition. These goals are best achieved through a series of individualized high-intensity compound movements that mirror functional mobility patterns and sufficiently stress the musculoskeletal system. As a result of adequate stress, the body will engage compensatory cellular mechanisms that improve the structural integrity of bones and muscles, stimulate metabolism and the immune system, optimize functional performance, and minimize mechanical injury risk. The current evidence suggests that application of the above exercise principles, practiced in a safe environment under expert observation, may offer patients with cancer an effective means of improving overall health and cancer-specific outcomes. The following article poses several important questions certified exercise specialists and physicians should consider when prescribing resistance exercise for patients with cancer.

Bone Tissue Responsiveness To Mechanical Loading-Possible Long-Term Implications of Swimming on Bone Health and Bone Development

PURPOSE OF REVIEW

To revisit the bone tissue mechanotransduction mechanisms behind the bone tissue response to mechanical loading and, within this context, explore the possible negative influence of regular swimming practice on bone health, particularly during the growth and development period.

RECENT FINDINGS

Bone is a dynamic tissue, responsive to mechanical loading and unloading, being these adaptative responses more intense during the growth and development period. Cross-sectional studies usually report a lower bone mass in swimmers compared to athletes engaged in weigh-bearing sports. However, studies with animal models show contradictory findings about the effect of swimming on bone health, highlighting the need for longitudinal studies. Due to its microgravity characteristics, swimming seems to impair bone mass, but mostly at the lower limbs. It is unkown if there is a causal relationship between swimming and low BMD or if other confounding factors, such as a natural selection whithin the sport, are the cause.

Sporting activity does not fully prevent bone demineralization at the impaired hip in athletes with amputation

There is lack of information about bone mineralization at the lumbar spine and bilateral hips of athletes with unilateral lower limb amputation. The present study assessed for the first time the areal bone mineral density at the lumbar spine and at the hip of the able and impaired leg by means of Dual-Energy X-Ray Absorptiometry using a large sample (N = 40) of male athletes. Results showed that bone demineralization in athletes with unilateral lower limb amputation is found at the impaired hip but not at the lumbar spine and may therefore be site-specific. The extent of hip demineralization was influenced by the level of amputation, with about 80% of athletes with above knee amputation and 10% of athletes with below knee amputation showing areal bone mineral density below the expected range for age. Nevertheless, a reduced percentage of fat mass and a lower fat-to-lean mass ratio in the residual impaired leg as well as a greater amount of weekly training was positively associated with bone mineralization at the impaired hip (partial correlation coefficients = 0.377–0.525, p = 0.040–0.003). Results showed that participation in adapted sport has a positive effect on bone health in athletes with unilateral lower limb amputation but is not sufficient to maintain adequate levels of bone mineralization at the impaired hip in athletes with above-knee amputation. Accordingly, physical conditioners should consider implementing sporting programs, according to the severity of the impairment, aimed at improving bone mineralization at the impaired hip and improve body composition in the residual impaired leg.

Modelling Changes in Bone and Body Composition Over a Season in Elite Male Footballers

This study investigated the change in bone and body composition characteristics of elite football players and recreationally active control participants across the course of a season. Fortysix participants (20 footballers and 26 recreationally active controls) were assessed by dual-energy x-ray absorptiometry and peripheral Quantitative Computed Tomography for a range of bone and body composition characteristics at four points over the course of a competitive season. Multilevel modelling was used to examine changes. Footballers had higher characteristics than controls for 24 out of 29 dual-energy x-ray absorptiometry and peripheral Quantitative Computed Tomography variables (all p<0.05). However, there was also significant random inter-individual variation in baseline values for all variables, for both footballers and controls (p < 0.05). Wholebody bone mineral density, leg and whole-body bone mineral content, tibial bone mass and area (38%) increased across the season in footballers (p < 0.05), and there was significant random inter-individual variation in the rate of increase of leg and whole-body bone mineral content (p<0.05). Whole-body bone mineral density, leg and whole-body bone mineral content, tibial bone mass and area (38%) increased over the course of the season in elite football players. The modelling information on expected changes in bone characteristics provides practitioners with a method of identifying those with abnormal bone response to football training and match-play.

The relationship between circulating hormone levels, bone turnover markers and skeletal development in healthy boys differs according to maturation stage

INTRODUCTION

This study investigates peri-pubertal changes in bone turnover markers, Wnt-signalling markers, insulin-like growth factor-1 (IGF-1) and sex steroid levels, and how they reflect skeletal development in peri-pubertal boys.

MATERIALS AND METHODS

Population-based study in 118 peri-pubertal boys from the NINIOS cohort (age range at baseline 5.1-17.3 years) with repeated measurements at baseline and after two years. Serum levels of the classical bone turnover markers (BTM) procollagen type 1 N-terminal propeptide and carboxy-terminal collagen crosslinks, as well as sex-hormone binding globulin, IGF-1, osteoprotegerin, sclerostin and dickkopf-1 were measured using immunoassays. Sex steroids (estradiol, testosterone, and androstenedione) were measured using mass spectrometry and free fractions calculated. Dual energy x-ray absorptiometry was used for bone measurements at the lumbar spine and whole body. Volumetric bone parameters and bone geometry at the proximal and distal radius were assessed by peripheral QCT. Pubertal development was categorized based on Tanner staging.

RESULTS

During puberty, sex steroid and IGF-1-levels along with most parameters of bone mass and bone size increased every next Tanner stage. In contrast, classical bone turnover markers and sclerostin peaked around mid-puberty, with subsequent declines towards adult values in late puberty. Especially classical BTM and sex steroid levels showed consistent associations with areal and volumetric bone parameters and bone geometry. However, observed associations differed markedly according to pubertal stage and skeletal site.

CONCLUSION

Serum levels of sex steroids, IGF-1 and bone metabolism markers reflect skeletal development in peri-pubertal boys. However, skeletal development during puberty is nonlinear, and the relations between skeletal indices and hormonal parameters are nonlinear as well, and dependent on the respective maturation stage and skeletal site.

Strength Training in Swimming

This narrative review deals with the topic of strength training in swimming, which has been a controversial issue for decades. It is not only about the importance for the performance at start, turn and swim speed, but also about the question of how to design a strength training program. Different approaches are discussed in the literature, with two aspects in the foreground. On the one hand is the discussion about the optimal intensity in strength training and, on the other hand, is the question of how specific strength training should be designed. In addition to a summary of the current state of research regarding the importance of strength training for swimming, the article shows which physiological adaptations should be achieved in order to be able to increase performance in the long term. Furthermore, an attempt is made to explain why some training contents seem to be rather unsuitable when it comes to increasing strength as a basis for higher performance in the start, turn and clean swimming. Practical training consequences are then derived from this. Regardless of the athlete's performance development, preventive aspects should also be considered in the discussion. The article provides a critical overview of the abovementioned key issues. The most important points when designing a strength training program for swimming are a sufficiently high-load intensity to increase maximum strength, which in turn is the basis for power, year-round strength training, parallel to swim training and working on the transfer of acquired strength skills in swim training, and not through supposedly specific strength training exercises on land or in the water.

State of Knowledge on Molecular Adaptations to Exercise in Humans: Historical Perspectives and Future Directions

For centuries, regular exercise has been acknowledged as a potent stimulus to promote, maintain, and restore healthy functioning of nearly every physiological system of the human body. With advancing understanding of the complexity of human physiology, continually evolving methodological possibilities, and an increasingly dire public health situation, the study of exercise as a preventative or therapeutic treatment has never been more interdisciplinary, or more impactful. During the early stages of the NIH Common Fund Molecular Transducers of Physical Activity Consortium (MoTrPAC) Initiative, the field is well-positioned to build substantially upon the existing understanding of the mechanisms underlying benefits associated with exercise. Thus, we present a comprehensive body of the knowledge detailing the current literature basis surrounding the molecular adaptations to exercise in humans to provide a view of the state of the field at this critical juncture, as well as a resource for scientists bringing external expertise to the field of exercise physiology. In reviewing current literature related to molecular and cellular processes underlying exercise-induced benefits and adaptations, we also draw attention to existing knowledge gaps warranting continued research effort. © 2021 American Physiological Society. Compr Physiol 12:3193-3279, 2022.

Vitamin D3 supplementation reduces serum markers of bone resorption and muscle damage in female basketball players with vitamin D inadequacy

This study aimed to investigate the effect of vitamin D₃ supplementation at a dose of 4,000 IU/day for 6 weeks on serum levels of: 25-hydroxyvitamin D [25(OH)D], bone turnover [osteocalcin and carboxy-terminal telopeptides of crosslinks of type I collagen (CTx-I)], and muscle damage [lactate dehydrogenase (LDH) and creatine kinase (CK)] in middle adolescent (15-18 years) and late-adolescent to early adulthood (19-30 years) female basketball players with inadequate vitamin D status. Participants (N=24) were randomly assigned in a double-blind manner into a vitamin D or placebo group. Data were analyzed using separate 2×2x2 mixed ANOVAs with one within-subjects factor (time) and two between-subjects factors (condition and age). When a significant interaction was observed, the intra-group changes were assessed using paired t tests and Hedge's g. Paired t-tests comparing intra-group changes in the vitamin D condition revealed a non-significant large improvement in 25(OH)D (p = 0.06; g = 0.86), non-significant small decreases in CTx-I (p = 0.13; g = -0.22) and CK (p = 0.07; g = -0.26), as well as a significant moderate decrease in LDH (p = 0.004; g = -0.74). Paired t-tests comparing intra-group changes in the placebo condition revealed a significant moderate decline in 25(OH)D (p <0.001; g = -0.77), as well as significant small increases in CTx-I (p = 0.04; g = 0.47) and CK (p = 0.04; g = 0.36). Vitamin D₃ supplementation at 4,000 IU/day could be effective in reducing bone resorption and muscle damage in female basketball players with inadequate baseline vitamin D, irrespective of age.

Bone mineral density in elite masters athletes: the effect of body composition and long-term exercise

BACKGROUND

The purpose of the study was to examine how bone mineral density (BMD) is related to body composition depending on the practiced sport (endurance, speed-power, throwing sports) in participants of the World Masters Athletics Championship.

METHODS

Dual-energy X-ray absorptiometry (DXA) was used to determine BMD and bone mass (BMC). Body composition was analyzed by means of the JAWON Medical X-scan analyzer using bioelectrical impedance methods. Percentage body fat (%BF), body fat mass (BFM), lean body mass (LBM), total body water (TBW), soft lean mass (SLM), intracellular water (ICW), and extracellular water (ECW) were evaluated.

RESULTS

Among men, the most important variables affecting the BMD norm were LBM (OR = 32.578; p = 0.023), ECW (OR = 0.003; p = 0.016) and ICW (OR = 0.011; p = 0.031), in the distal part and SLM (OR = 5.008; p = 0.020) and ICW (0.354, p = 0.008) in the proximal part. In women, the most important predictors of normal BMD were ICW (OR = 10.174; p = 0.003) and LBM (OR = 0.470; p = 0.020) in the distal part and ICW (OR = 5.254; p = 0.038) in the proximal part.

CONCLUSION

The representatives of strength based events had the most advantageous BMD levels. The condition of bone tissue evaluated by BMC and BMD of the forearm in masters athletes was strongly determined by the level of lean body components and the type of sports training associated with the track and field event. In the most important predictors of the BMD norm were also hydration components ECW and ICW. However, this relationship requires more research on the nature and mechanisms of these interactions.

Relationship between muscular fitness and bone health in young baseball players

The physical actions developed by baseball players can increase muscular fitness, and consequently improve bone health. The objective was to relate some indicators of muscular fitness to bone health in young baseball players. A descriptive cross-sectional study was carried out in 102 children and adolescent baseball players of the Brazilian National Team. The age range ranged from 9.0 to 15.0 years, the average chronological age was 12.2±2.2 years and the maturity status was 14.8±0.5 APHV (age at peak height velocity). Anthropometry, body composition [% fat, fat mass (FM) and fat-free mass (FFM)], physical tests [horizontal jump (HJ) and medicine ball throw (MBT)] bone health was estimated by anthropometry [bone mineral density (BMD) and bone mineral content (BMC)]. There was positive and significant correlation between bone health with FFM (r2= 89%) and with muscle strength tests (HJ and MBT) (R2= 55 to 75%). Young baseball players classified with low bone health level, reflected decreased values of FFM, HJ and MBT, in relation to young players classified with moderate and high bone health level (p<0.05). It was shown that good bone health is a consequence of a greater presence of muscular fitness, as a result of increased physical activity. These results suggest that emphasis should be placed on those young people who present a greater risk of having low BMD and BMC.

Comparison of bone mineral density and bone mineral content in university athletes from different sports

INTRODUCTION

Bone parameters are influenced by multiple factors. However, when comparing sports, few studies have considered the simultaneous interference of these factors in bone parameters.

OBJECTIVE

To compare bone mineral density (BMD) and bone mineral content (BMC) between university athletes from different sports, according to sex.

APPROACH

Cross-sectional study with 71 male (M) and female (F) university athletes practicing indoor soccer (M = 14, F = 20), judo (M = 8, F = 6) and volleyball (M = 11, F = 12) aged 22.37 (± 3.71) years. Dependent variables were BMD and BMC corrected by height measured by dual energy X-ray absorptiometry. The sport practiced (indoor soccer, judo and volleyball) was the independent variable and covariates were fat mass, lean tissue mass, training volume, practice time and gynecological aspects (in females athletes) such as regular menstruation and use of oral contraceptives. Analysis of covariance was used, with p <0.05.

RESULTS

Female volleyball players [mean: 1.23; Standard Error (SE): 0.03] presented higher lumbar BMD values compared to judo athletes (mean: 1.08; SE: 0.05). In addition, lumbar BMC values of indoor soccer athletes (mean: 0.41; SE: 0.01) was higher compared to judo athletes (mean: 0.34; SE: 0.02). In males, no differences were observed among sports.

CONCLUSIONS

Sports performance technicians and professionals will be able to broaden the understanding of variations in BMD and BMC lumbar between judo, indoor soccer and volleyball athletes, which allows monitoring these parameters in the sports context and in the athlete's health.

[Musculoskeletal laboratory diagnostics in competitive sport]

Hintergrund

Die labordiagnostische Untersuchung stellt eine wichtige Möglichkeit zur Beurteilung und Optimierung der Leistungs- und Regenerationsfähigkeit professioneller Athleten dar. Ferner ist sie für die Prävention, Diagnostik und Rehabilitation von Verletzungen und Überbelastungen von Bedeutung.

Fragestellung

Ziel dieser Arbeit ist die Darstellung muskuloskelettaler laborchemischer Parameter, die relevante Erkenntnisse für die medizinische Betreuung von Leistungssportlern liefern.

Material und Methoden

Literaturrecherche und narratives Review.

Ergebnisse

Die Bestimmung des Vitamin-D-, Calcium- und Knochenstoffwechsels stellt die laborchemische Basisdiagnostik im Rahmen der Beurteilung des Skelettstatus mit zusätzlichem präventivem Nutzen bezüglich muskuloskelettaler Verletzungen dar. Ferner können muskuläre Serummarker, z. B. Laktatdehydrogenase (LDH), Kreatinkinase (CK), Myoglobin und Aspartat-Aminotransferase (ASAT), helfen, eine metabolische Adaptation an das physische Training festzustellen und Aussagen über die muskuläre Arbeitslast und mögliche Schädigungen zu gewinnen. Die Energieverfügbarkeit kann durch eine entsprechende Bilanzierung sowie die laborchemische Bestimmung der Makro- und Mikronährstoffe eingeschätzt und optimiert werden.

Schlussfolgerungen

Die labordiagnostische Untersuchung besitzt in der Betreuung von Athleten eine sportartenübergreifende klinische Relevanz. Sie dient der Erreichung einer höchstmöglichen Leistungsfähigkeit sowie optimalen Prävention von Knochen- und Muskelverletzungen, wobei sämtliche Mangelzustände (z. B. Vitamin D) ausgeglichen werden sollten. Durch eine Periodisierung der laborchemischen Untersuchungen, mit zumindest zwei Labordiagnostiken im Jahr, und Aufstellung individueller Variabilitäts- und Referenzbereiche kann ferner eine bessere Beurteilbarkeit erreicht werden.

The Bone Metabolic Response to Exercise and Nutrition

Bone (re)modeling markers can help determine how the bone responds to different types, intensities, and durations of exercise. They also might help predict those at risk of bone injury. We synthesized evidence on the acute and chronic bone metabolic responses to exercise, along with how nutritional factors can moderate this response. Recommendations to optimize future research efforts are made.

Geometric indices of femur bone strength in female handball players

The practice of sports during the growth phase has a positive influence on bone mineral accrual. However, the effects of different sports are still not fully understood. The aim of this study was to evaluate the bone geometry in adolescent handball players. This is a cross-sectional study in which 53 female adolescents (12-17 years old) were divided into two groups: handball players (HG: n = 26), who must have had at least six months of participation in official competitions, and a control group (CG: n = 27). Bone geometry properties, such as cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), section modulus (Z), and femoral strength index (FSI) were measured using DXA. Tanner's sexual maturity, menarche, peak height velocity, sun exposure, and calcium intake were assessed. An unpaired Student's t test or the Mann-Whitney test and multivariate analyzes were used to compare variables differences between groups. The HG group showed a significantly higher body mass index, weight and lean mass (LST), CSA, CSMI, Z, and FSI than the CG group. When the values were adjusted for LST, the differences disappeared. The LST has been shown to be relevant to the strength and bone stiffness of the femurs of female adolescents, and the competitive practice in handball may have contributed to its increase.

Relationship between tartrate-resistant acid phosphatase 5b and stress fractures in female athletes

BACKGROUND

Approximately 10% of female athletes have a history of stress fractures, which most commonly occur between the ages of 16 and 17 years old.

PURPOSE

We investigated whether tartrate-resistant acid phosphatase 5b (TRACP-5b), which is a bone resorption marker, can serve as a valid predictor of stress fractures in female athletes in their teens and 20s.

METHODS

Three hundred and sixteen elite female athletes were recruited between 2013 and 2015. Serum TRACP-5b and various hormones were examined in blood samples. The serum TRACP-5b level was compared between athletes with and without stress fractures within 3 months after the initial collection of their blood samples.

RESULTS

The 316 athletes were divided into two age groups: 13-19 years old and 20-29 years old. Thirty-six athletes (11.4%) experienced new stress fractures within 3 months after the initial collection of their blood samples. The median serum TRACP-5b level was significantly higher in teenage athletes with new stress fractures than in teenage athletes without new stress fractures. In univariate logistic regression analysis, the Z-score of serum TRACP-5b was a significant predictive factor of stress fractures in teenage athletes only (odds ratio: 1.87; 95% CI: 1.31-2.66; P < 0.0012).

CONCLUSION

For teenage female athletes, TRACP-5b is a predictor of the risk of stress fractures, and measuring TRACP-5b levels may be useful to prevent stress fractures.

SWIMMING AND BONE MINERAL DENSITY: A SPORT WITHOUT OSTEOGENIC STIMULATION?

ABSTRACT Introduction: The osteogenic effects generated by different sports are the subject of a growing number of research projects. Regular physical activity is one of the main recommendations for the stimulation of bone mineral density (BMD). However, evidence has shown that not all physical activities promote similar effects. In this context, the osteogenic effects of swimming need to be clarified. Objective: To verify and compare total and regional BMD levels between male and female swimming athletes and university non-athletes. Methods: The sample, composed of 60 participants of both sexes, was divided into two groups: 30 swimming athletes (GA): 15 men (22.2 ± 3.92 years; 73.61 ± 16.55 kg; 1.76 ± 0.08 m) and 15 women (21.91 ± 2.21 years; 53.15 ± 8.36 kg; 1.64 ± 0.06 m) and a control group (CG): 30 university non-athletes: 15 men (20.73 ± 1.27 years; 74.4 ± 5.54 kg, 1.74 ± 0.04 m) and 15 women (19.93 ± 2.05 years; 59.72 ± 1.33 kg; 1.63 ± 0.004 m). BMD (total, arms, legs, pelvis and spine) was measured using dual energy X-ray absorptiometry (DXA). The results were compared with one-way ANOVA using Scheffé's post hoc test, when necessary. Results: When compared with the women, the men of both groups presented superior results for all BMD values analyzed. In addition, GA had higher BMD of arms and spine when compared to the CG, both for males (p = 0.016 and p = 0.001, respectively) and females (p = 0.0001 and p = 0.011, respectively). Conclusions: The results of this study demonstrate that young male adults, athletes and non-athletes, present higher levels of BMD than their peers of the opposite sex. In addition, the results suggest that when undertaken for competitive purposes and with a weekly training volume of 12 hours or more, swimming may be beneficial for the bone development of young athletes when compared to non-athlete controls. Level of evidence III; Retrospective comparative study.

Increases in PYY and uncoupling of bone turnover are associated with loss of bone mass after gastric bypass surgery

CONTEXT

The gut hormones peptide YY (PYY) and ghrelin mediate in part the metabolic benefits of Roux-en-Y gastric bypass (RYGB) surgery. However, preclinical data suggest these hormones also affect the skeleton and could contribute to postoperative bone loss.

OBJECTIVE

We investigated whether changes in fasting serum total PYY and ghrelin were associated with bone turnover marker levels and loss of bone mineral density (BMD) after RYGB.

DESIGN, SETTING, PARTICIPANTS

Prospective cohort of adults undergoing RYGB (n=44) at San Francisco academic hospitals.

MAIN OUTCOME MEASURES

We analyzed 6-month changes in PYY, ghrelin, bone turnover markers, and BMD by dual-energy x-ray absorptiometry (DXA) and quantitative computed tomography (QCT). We calculated the uncoupling index (UI), reflecting the relative balance of bone resorption and formation.

RESULTS

Postoperatively, there was a trend for an increase in PYY (+25pg/mL, p=0.07) and a significant increase in ghrelin (+192pg/mL, p<0.01). PYY changes negatively correlated with changes in spine BMD by QCT (r=-0.36, p=0.02) and bone formation marker P1NP (r=-0.30, p=0.05). Relationships were significant after adjustments for age, sex, and weight loss. No consistent relationships were found between ghrelin and skeletal outcomes. Mean 6-month UI was -3.3; UI correlated with spine BMD loss by QCT (r=0.40, p=0.01).

CONCLUSIONS

Postoperative PYY increases were associated with attenuated increases in P1NP and greater declines in spine BMD by QCT. Uncoupling of bone turnover correlated with BMD loss. These findings suggest a role for PYY in loss of bone mass after RYGB and highlight the relationship between intestinal and skeletal metabolism.

Association between changes in molecular biomarkers of cartilage matrix turnover and changes in knee articular cartilage: a longitudinal pilot study

Background

An early detection of Osteoarthritis is urgently needed and still not possible until today. The aim of the study was to assess whether molecular biomarkers of cartilage turnover are associated with longitudinal change in knee cartilage thickness during a 2 year period in individuals with increased risk of developing knee osteoarthritis. A secondary aim was to assess whether prior knee injury or subjective patient-reported outcomes at baseline (BL) were associated with articular cartilage changes. Nineteen volleyball players (mean age 46.5 ± 4.9 years, 47% male) with a 30-year history of regular high impact training were recruited. The serum biomarkers Cpropeptide of type II procollagen (CPII), cartilage oligomeric matrix protein (COMP), collagenase generated carboxy-terminal neoepitope of type II collagen (sC2C), cartilage intermediate layer protein 2 (CILP-2), and the urine biomarkers C-telopeptide of type II collagen (CTX-II) and collagenase-generated peptide(s) of type II collagen (C2C-HUSA) were assessed at BL and at 2 year follow up (FU). Femorotibial cartilage thinning, thickening and absolute thickness change between BL and FU was evaluated from magnetic resonance imaging. Subjective clinical status at BL was evaluated by the International Knee Documentation Committee Subjective Knee Form and the Short-Form 36 Physical Component Score.

Results

CILP-2 was significantly higher at FU and linearly associated with the absolute cartilage thickness change during the experimental period. Prior injury was a predictor of increased absolute cartilage thickness change.

Conclusion

Measuring the change in the cartilage biomarker CILP-2 might be a valid and sensitive method to detect early development of knee osteoarthritis as CILP-2 appears to be related to cartilage thickness loss in certain individuals with increased risk of developing knee osteoarthritis. Prior knee injury may be predictive of increased articular cartilage thickness change.

Analysis of Bone Mineral Density/Content of Paratroopers and Hoopsters

The different mechanical stimulus affects the bone mass and bone strength. The aim of this study was to investigate the effect of landing posture of the hoopster and paratrooper on the bone mass. In this study, 39 male participants were recruited including 13 paratroopers, 13 hoopsters, and 13 common students (control groups). Bone area (BA), BMD and BMC of calcaneus, and 1-5th of the metatarsus, hip, and lumbar spine (L₁-L₄) were measured by the dual-energy X-ray absorptiometry. Also, the vertical ground reaction forces (GRFs) of hoopsters and paratroopers were measured by the landing of 1.2 m 3D force platform. BA of hoopsters at the calcaneus, lumbar spine, and hip were significantly higher than the control group. The lumbar spine, hip, calcaneus, the 1st and 2nd metatarsals, BMC of paratroopers, and control groups were significantly lower than hoopsters. BMD of the lumbar spine, hip, and right and left femoral necks in hoopsters were significantly higher than the other participants. BMC and BMD of lower limber showed no significant difference between paratroopers and the control group. Besides, peak GRFs of paratroopers (11.06 times of BW) were significantly higher than hoopsters (6.49 times of BW). The higher GRF in the landing train is not always in accordance with higher BMD and BMC. Variable loads in hoopsters can improve bone remodeling and play an important role in bone expansions for trabecular bones. This will be considered by the method of training to prevent bone loss.

SNPs in the vicinity of P2X7R, RANK/RANKL/OPG and Wnt signalling pathways and their association with bone phenotypes in academy footballers

CONTEXT

Genotype plays an important role in influencing bone phenotypes, such as bone mineral density, but the role of genotype in determining responses of bone to exercise has yet to be elucidated.

OBJECTIVE

To determine whether 10 SNPs associated with genes in the vicinity of P2X7R, RANK/RANKL/OPG and Wnt Signalling Pathways are associated with bone phenotypes in elite academy footballers (Soccer players) and to determine whether these genotypes are associated with training induced changes in bone. Design, participants, and methods: 99 elite academy footballers volunteered to participate. Peripheral computed tomography of the tibia (4%, 14%, 38% and 66% sites) was performed immediately before and 12 weeks after an increase in football training volume. Genotypes were determined using proprietary fluorescence-based competitive allele-specific PCR assays.

RESULTS

No significant genotype by time interactions were shown for any of the SNPs analysed (P > .05). A main effect of genotype was shown. SOST SNP rs1877632 (trabecular density), P2X7R SNPs rs1718119 (cortical thickness and CSA), rs3751143 (SSI, CSA, cortical CSA and periosteal circumference) RANK/RANKL/OPG SNPs rs9594738 (periosteal circumference), rs1021188 (cortical thickness and CSA) and rs9594759 (cortical density) were associated with bone phenotypes (P < .05).

CONCLUSIONS

No association was shown between P2X7R, RANK/RANKL/OPG and Wnt Signalling SNPs and a change in bone phenotypes following 12 weeks of increased training volume in elite academy footballers. However, SNPs were associated with bone phenotypes pre training. These data highlight the complexity of the interaction between SNPs in the vicinity of the RANK/RANKL/OPG, P2X7R and Wnt metabolic regulatory pathways and bone phenotypes in elite academy footballers.

The befuddling nature of mouse lemur hands and feet at Bezà Mahafaly, SW Madagascar

The reddish-gray mouse lemur (Microcebus griseorufus) possesses striking phenotypic and behavioral variation. This project investigates differences in autopod proportions in neighboring populations of M. griseorufus from the Special Reserve at Bezà Mahafaly in southwest Madagascar. One population resides in an environment generally preferred by M. griseorufus-a spiny forest with large-trunked trees, vertically-oriented supports, and more open ground, while the other resides in a gallery forest with abundant small, often horizontal peripheral branches in high canopy. We demonstrate significant interpopulation differences in autopod morphophology despite no evidence of divergence in mitochondrial cytochrome b. We test two hypotheses regarding ultimate causation. The first, based on the Fine Branch Arborealism Hypothesis (FBAH), holds that autopod differences are related to different locomotor practices in the two environments, and the second, based on the Narrow Niche Hypothesis (NNH), holds that the observed differences reflect a relaxation (from ancestral to descendant conditions) of selective pressure for terrestrial locomotion and/or use of large, vertical supports combined with positive selection for locomoting in peripheral branch settings. Our data conform well to FBAH expectations and show some support for the NNH. Individuals from the gallery forest possess disproportionally long posterior digits that facilitate locomotion on small, flexible canopy supports while individuals from the spiny forest possess shorter posterior digits and a longer pollex/hallux that increase functional grasping diameter for large vertical supports and facilitate efficient ground locomotion. Focal individual data confirm differences in how often individuals descend to the ground and use vertical supports. We further show that predispersal juveniles, like adults, possess autopod morphologies suited to their natal forest. We explore two proximate mechanisms that could generate these cheiridial differences. The first posits an in vivo plastic response to different locomotor behaviors, the second posits differences that manifest in early development.

Seasonal Variations of Bone Metabolism and Bone Mineral Density in Collegiate Alpine Skiers

Sato, T, Sakuraba, K, Tsuchiya, Y, Maruyama, S, and Ochi, E. Seasonal variations of bone metabolism and bone mineral density in collegiate alpine skiers. J Strength Cond Res 32(5): 1448-1454, 2018-This study investigated the seasonal variations in bone metabolism, mineral density, and physical characteristics in collegiate alpine skiers. Twelve male subjects (20.6 ± 1.5 years) were evaluated for body composition, bone mineral density (BMD), serum levels of osteocalcin (OC), bone alkaline phosphatase (BAP), tartrate-resistant acid phosphatase 5b (TRACP-5b), parathormone, and 25-hydroxy vitamin D. We also measured the knee extensor and flexor strength, maximal power, and vertical jump. Measurements were conducted in the preseason period (T1), competitive period (T2), end-of-season period (T3), and resting period (T4). The percentage of body fat significantly increased from T1 to T2-T4 (p < 0.05), but lean body mass significantly decreased from T1 to T2-T4 (p < 0.05). Although BMD increased at T2 (0.9%) and T3 (0.8%), as compared with that at T1 (p < 0.05), BAP and OC decreased at T2 and T3, as compared with that at T1 (p < 0.05). Tartrate-resistant acid phosphatase 5b significantly increased from T1 to T2 (p < 0.05). We concluded that it is important to monitor bone metabolism markers and BMD of male alpine skiers throughout the season.

Swimming and peak bone mineral density: A systematic review and meta-analysis

This meta-analysis aims to determine the effects of regular swimming on bone mineral density (BMD) in young adults (18-30 years). A systematic search was performed in Pubmed, SPORTDiscus and the Cochrane Library from the earliest possible year to March 2016. Swimmers were compared to non-athletic controls (CG) and to high-impact athletes (HIGH). Effect sizes with the Hedges g in random effects models were developed. Fourteen studies met the inclusion criteria and were included in the meta-analyses. Swimmers presented similar BMD values to CG in whole-body (g = -0.20; P = 0.251), femoral neck (g = -0.05; P = 0.818) and lumbar spine (g = 0.18; P = 0.492); and lower BMD in the whole-body (g = -1.21; P < 0.001), femoral neck (g = -1.51; P < 0.001) and lumbar spine (g = -0.84; P = 0.017) than the HIGH. For the whole-body differences, the higher the latitude the smaller the differences between swimmers and HIGH (B = 0.10; P = 0.001). For the femoral neck differences, age also seemed to reduce the differences between groups (B = 0.19; P = 0.020). Young adult swimmers present similar BMD values than CG and lower values than HIGH.

Level of serum undercarboxylated osteocalcin correlates with bone quality assessed by calcaneal quantitative ultrasound sonometry in young Japanese females

The diagnostic criteria of osteoporosis were established based on bone mineral density (BMD). Therefore, BMD measured by dual energy X-ray absorptiometry has been recognized as the gold standard to diagnose osteoporosis. However, discrepancies between fracture risk and BMD have been recognized. Bone is composed of collagen scaffold reinforced by hydroxyapatite. Both protein scaffold and hydroxyapatite are involved in bone quality. BMD may indicate bone mineralization but potentially fail to assess the protein scaffold. Vitamin K contributes to bone mineralization and as a protein scaffold. A deficiency of vitamin K upregulates the level of serum undercarboxylated osteocalcin (ucOC), and serum ucOC correlates with fracture risk. However, direct association of ucOC and bone quality has not been demonstrated. For the present study, a total of 49 healthy young Japanese female college students underwent calcaneal; quantitative ultrasound sonometry (QUS) and determination of serological bone metabolic markers. QUS parameters were significantly correlated with serum 25-hydroxyvitamin D (25-OH-D) concentrations (P<0.05). A significant negative correlation was also identified between log transformed serum ucOC concentrations [Ln(ucOC)] and a QUS parameter, speed of sound (SOS) (P<0.05). Stepwise multiple regression analysis indicated that Ln(ucOC) was an independent determinant of SOS, and 25-OH-D was an independent determinant of the other two QUS parameters, transmission index (TI) and synthetic parameter osteo-sono-assessment index. As vitamin D is involved in bone mineralization, TI may reflect the mineralization. Correlation of vitamin K status, indicated by ucOC, with SOS may clarify the correlation between vitamin K status and bone quality, although the material factors that connect them have not been identified.

The analysis of knee joint loading during drop landing from different heights and under different instruction sets in healthy males

Background

Mechanical loading during exercise has been shown to promote tissue remodeling. Safe and accessible exercise may be beneficial to populations at risk of diminished bone and joint health. We examined the effect of drop height and instruction on knee loading during a drop-landing task and proposed a task that makes use of drop heights that may be appropriate for rehabilitation purposes and functional in daily life to examine transient knee joint loads.

Methods

Twenty males (22.0 ± 2.8 years) performed drop landings from 22 cm (low) and 44 cm (high) heights, each under three instructions: “land naturally” (natural), “softly” (soft), and “stiffly” (stiff). Knee compression force and external flexion moment were estimated using three-dimensional inverse dynamics and normalized to body mass.

Results

Peak knee compression force was larger (p < 0.001) for high (17.8 ± 0.63 N/kg) than low (14.8 ± 0.61 N/kg) heights. There was an increase (p < 0.001) in the knee compression force across soft (11.8 ± 0.40 N/kg), natural (17.0 ± 0.62 N/kg), and stiff (20.2 ± 0.67 N/kg) instructions. Peak knee flexion moment in high-natural (2.12 ± 0.08 Nm/kg) was larger (p < 0.001) than in high-soft (1.88 ± 0.08 Nm/kg), but lower than in high-stiff (2.23 ± 0.08 Nm/kg). No differences in peak knee flexion moment were observed across instructions for the low height.

Conclusions

We propose a drop-landing task that creates a scalable increase in knee compression loading. The absence of increased knee flexion moment with drop from the low height, compared to high, suggests that individuals could perform the task without incremental risk of knee injury. This task could be used in future studies to examine the effect of acute bouts of mechanical loading on bone and cartilage metabolism.

Controlled Pilot Study of High-Impact Low-Frequency Exercise on Bone Loss and Vital-Sign Stabilization in Adolescents With Eating Disorders

PURPOSE

Adolescents with anorexia nervosa (AN) face an increased lifetime risk of bone fragility. This randomized controlled study examined the efficacy and safety of a high-impact activity program on markers of bone turnover and stabilization of vital signs (VSS).

METHODS

Forty-one hospitalized adolescents with AN were randomly assigned to routine care or routine care plus 20 jumps twice daily. Bone markers were measured at baseline days 1-3 (T1), days 4-6 (T2), and days 7-9 (T3). The primary outcome was change in bone-specific alkaline phosphatase (BSAP) at T3 adjusted for BSAP and % median body mass index at T1. Secondary outcomes were serum N-telopeptide (NTX) and osteocalcin at T3. Safety was determined by comparing weight gain, time to VSS and length of stay for each group.

RESULTS

BSAP, NTX, or osteocalcin did not differ between groups at baseline or at T3. BSAP and NTX at T3 were not associated with group of enrollment or % median body mass index. VSS was significantly reduced in the intervention group compared with the control group (11.6 ± 5.7 days vs. 17 ± 10.5 days, p = .049). There was no significant difference in weight gain or length of stay between groups.

CONCLUSIONS

Twice-daily jumping activity failed to influence markers of bone turnover in adolescents with AN but was well tolerated, shortened time to vital-sign stabilization and did not slow weight gain.

Exercise Training Alters the Bone Mineral Density of Hemodialysis Patients

Marinho, SM, Moraes, C, Barbosa, JEdSM, Eduardo, JCC, Fouqe, D, Pelletier, S, and Mafra, D. Exercise training alters the bone mineral density of hemodialysis patients. J Strength Cond Res 30(10): 2918-2923, 2016-Patients with chronic kidney disease undergoing hemodialysis (HD) frequently present low bone mineral density (BMD), and exercise may be useful for treating bone loss. This study aimed to assess the effects of an intradialytic resistance exercise training program (RETP) on BMD in HD patients. Twenty-one patients were enrolled into 2 groups; 10 patients performed exercise (80.0% men; 46.9 ± 12.1 years; 27.0 ± 3.4 kg·m) and 11 patients were in the control group (54.5% men; 50.5 ± 11.5 years; 24.1 ± 8.7 kg·m). Dual-energy x-ray absorptiometry was used to measure the BMD, lean mass, and body fat before and after the supervised RETP (performed with elastic bands and ankle cuffs in both lower limbs 3 times a week for 24 weeks-72 sessions). In the exercise group, 30.0% of patients presented with osteopenia and 20.0% osteoporosis and in the control group, 45.5% osteopenia and 36.4% osteoporosis. Only in the exercise group, the osteoporosis percentage was reduced to 10.0% and the femoral neck BMD and T-score improved from 0.89 ± 0.1 to 0.93 ± 0.1 g·cm and from -1.3 ± 0.8 to -1.0 ± 0.8 g·cm (p ≤ 0.05), respectively, after the intervention. In contrast, these parameters were reduced in the control group. The results suggest that resistance exercise may be useful for improving the BMD in HD patients. In summary, 24 weeks of the supervised RETP played a role in improving the BMD of HD patients.

The Effect of Swimming During Childhood and Adolescence on Bone Mineral Density: A Systematic Review and Meta-Analysis

BACKGROUND

The effects of swimming on bone mineral density (BMD) have been studied by several researchers, with inconsistent results.

AIM

This meta-analysis aims to determine whether systematic swimming training may influence BMD during childhood and adolescence.

METHODS

A systematic search was performed in PubMed, SPORTDiscus and ClinicalTrials.gov from the earliest possible year to March 2015, with data extraction and quality assessment performed independently by two researchers following the PRISMA methodology. Swimmers were compared to sedentary controls and to athletes performing highly osteogenic sports. Therefore, a total of two meta-analyses were developed.

RESULTS

Fourteen studies met the inclusion criteria and were included in the meta-analyses. Swimmers presented similar BMD values to sedentary controls and lower than other high-impact athletes. Femoral neck and lumbar spine BMD differences between swimmers and sedentary controls and between swimmers and athletes practicing osteogenic sports appeared to increase with age and favored the non-swimming groups. There were no differences by sex.

CONCLUSION

While swimming is associated with several health benefits, it does not appear to be an effective sport for improving BMD. Swimmers might be in need of additional osteogenic exercises for increasing BMD values.

Vitamin D in relation to bone health and muscle function in young female soccer players

The present work investigated serum vitamin D (25(OH)D) status in relation to bone and muscle qualities and functions in 19 female soccer players (13-16 years) resident at northern latitude with very low sun exposure (∼32-36 h/month) during winter season (late January to early March). Serum 25(OH)D, parathyroid hormone and bone turnover markers osteocalcin (OC) and beta carboxy-terminal collagen cross-links (β-Ctx), as well as body composition and muscle performance were examined. Hormones were tested using routine laboratory methods. Fat mass, lean mass, and bone mineral density in whole body, as well as femur and lumbar spine were evaluated with dual-energy X-ray absorptiometry. Muscle performance was assessed through isokinetic knee extension and flexion, countermovement jump, and sprint running. 25(OH)D was low (50.5 ±   12.8 nmol l^-1), whereas the values of bone turnover markers were markedly high (OC: 59.4 ±   18.6 µg l^-1; β-Ctx: 1075 ±   408 ng l^-1). All bone and muscle measurements were normal or above normal. 25(OH)D was not significantly correlated with most of the parameters of bone and muscle quality or function, except the knee extension time to peak torque (r   =   -0.50, p =   .03). In conclusion, the level of vitamin D is markedly low in adolescent female soccer players during the winter in Sweden. However, vitamin D levels did not significantly correlate with measures of bone and muscle except a moderate correlation in time to peak torque in the knee extensors. The practical implication of low vitamin D levels in young growing female athletes remains unclear.

A review of the effect of swim training and nutrition on bone mineral density in female athletes

PURPOSE

The present paper reviews the physiological adaptation to swim training and dietary supplementation relating to bone mineral density (BMD) in female swimmers. Swim training still seems to have conflicting effects on bone health maintenance in athletes.

METHODS

This review article focuses on swim training combined with dietary supplementation with respect to BMD in female athletes.

RESULTS

Upon review of previous studies, it became obvious that the majority of studies did not collect physical activity data on the swimmers outside of their swimming activities. These activities may have some influence on the BMD of swimmers and therefore, future studies need to examine additional physical activity history data as well as swim training. This additional information may help to explain why swimmers' BMD tends to be lower than the BMD of control individuals in many studies. Moreover, dietary supplementation such as calcium, magnesium, and vitamin D also affect bone health in swimmers, and it is extremely important to evaluate BMD in the context of dietary supplementation.

CONCLUSION

A review of the literature suggests that exercise intervention studies, including longitudinal and randomized control trials, need to attempt to introduce various exercise programs to female swimmers in order to determine the optimal exercise prescription for bone health.

Seasonal variations in vitamin D status in indoor and outdoor female athletes

Vitamin D (VD) insufficiency is a concern, particularly among young females. The VD status shows seasonal variations, since it correlates with duration of sunlight exposure. VD insufficiency in indoor athletes is therefore suggested in winter. The aim of the present study was to determine seasonal variations in VD and bone status among indoor and outdoor female athletes. The prospective study was conducted in participants aged 20-22 years old. The participants comprised of 15 indoor and 15 outdoor athletes. The biochemical markers and bone parameters were measured in March, June, September and December. The serum 25-hydroxyvitamin D (25-OH-VD) concentration showed a seasonal oscillation, with a nadir in March (indoor, 19±4.0 ng/ml; outdoor, 32±2.7 ng/ml) and a peak in September (indoor, 32±6.6 ng/ml; outdoor, 39±5.7 ng/ml). The amplitude of oscillation was greater in the indoor compared to the outdoor athletes. Seasonal variations in serum calcium exhibited a similar pattern, while the parathyroid hormone showed an inverse pattern to serum 25-OH-VD. The nadir in bone mass, measured as speed of sound, occurred in June after peaking in December among the indoor and outdoor athletes. The pattern followed 3 months after the changes in 25-OH-VD. Indoor sports athletes are more susceptible to VD insufficiency compared to outdoor sports athletes. Insufficiency is most likely to arise in winter, and could affect bone mineralization observed 3 months after.

The Effect of the Modified Eighth Section of Eight-Section Brocade on Osteoporosis in Postmenopausal Women: A Prospective Randomized Trial

Osteoporosis and related fragility fractures represent a serious and global public health problem. To evaluate whether the modified eighth section of Eight-section Brocade (MESE) exercise could improve the symptom and indexes associated with osteoporosis in postmenopausal women. Guangzhou and Liuzhou hospital of traditional Chinese medicine in China. Women (n = 198) aged 50 to 75 years were randomized into Control, Ca, MESE, and MESE + Ca. Subjects in Ca and MESE groups were separately asked to consume thrice daily Calcium Carbonate Chewable D3 tablet and to perform thrice daily MESE exercise by 7 repetitions per time for 12 months. Subjects in MESE + Ca group performed such the combined treatment project for 12 months. Body height and Hospital for Special Surgery (HSS) scores of both knees, chronic back pain visual analogue scale scores (VAS), bone mineral density (BMD) at L2 to L4 and the left femoral neck, 3-feet Up and Go Test (3') and one-leg Stance (OLS). In our study, the improvement in chronic back pain of the patients in Ca, MESE, and MESE + Ca group was better than that in control group. There was 1.9% and 1.7%, 2.3%, and 2.1% net profit in left femoral neck and lumbar BMD after the treatment for 12 months in MESE and MESE + Ca groups. For the balance capacity, the subjects in MESE and MESE + Ca groups secured much better performance than those in Ca and control group after the treatment for 12 months (P < 0.001, P < 0.001). The treatment of MESE exercise is the most effective for the improvement of the symptom and indexes in postmenopausal women. Importantly, the low attrition and the high exercise compliance indicate that MESE exercise is safe, feasible, and well tolerated by postmenopausal women.

The Influence of Organized Physical Activity (Including Gymnastics) on Young Adult Skeletal Traits: Is Maturity Phase Important?

We prospectively evaluated adolescent organized physical activity (PA) as a factor in adult female bone traits. Annual DXA scans accompanied semiannual records of anthropometry, maturity, and PA for 42 participants in this preliminary analysis (criteria: appropriately timed DXA scans at ~1 year premenarche [predictor] and ~5 years postmenarche [dependent variable]). Regression analysis evaluated total adolescent interscan PA and PA over 3 maturity subphases as predictors of young adult bone outcomes: 1) bone mineral content (BMC), geometry, and strength indices at nondominant distal radius and femoral neck; 2) subhead BMC; 3) lumbar spine BMC. Analyses accounted for baseline gynecological age (years pre- or postmenarche), baseline bone status, adult body size and interscan body size change. Gymnastics training was evaluated as a potentially independent predictor, but did not improve models for any outcomes (p > .07). Premenarcheal bone traits were strong predictors of most adult outcomes (semipartial r2 = .21-0.59, p ≤ .001). Adult 1/3 radius and subhead BMC were predicted by both total PA and PA 1-3 years postmenarche (p < .03). PA 3-5 years postmenarche predicted femoral narrow neck width, endosteal diameter, and buckling ratio (p < .05). Thus, participation in organized physical activity programs throughout middle and high school may reduce lifetime fracture risk in females.

Adolescent undernutrition and early adulthood bone mass in an urbanizing rural community in India

The long-term effects on bone health of nutritional status in adolescence are unclear. The impact of adolescent and current body mass on bone mass in young adulthood in rural India was assessed. Current lean mass was a more important determinant of bone mass than thinness during adolescence in this population.

PURPOSE/INTRODUCTION

Adolescence is a crucial period for skeletal growth. However, the long-term effects on bone health of nutritional status in adolescence, particularly in the context of nutritional transition, are unclear. The current manuscript assessed the impact of adolescent and current body size on bone mass in young adulthood in an Indian rural community that is undergoing rapid socioeconomic changes.

METHODS

The Andhra Pradesh Children and Parents Study is a prospective cohort study in Hyderabad, India. In 2003-2005, the study collected anthropometric and cardiovascular data on adolescents (mean age = 16 years old). The second and third waves of the study in 2009-2012 collected data on current anthropometric measures, areal bone mineral density (aBMD) in hip and lumbar spine (L1-L4) measured by dual-energy X-ray absorptiometry, and living standards of the trial participants who were now young adults (mean age = 22 years old).

RESULTS

The median body mass index (BMI) of the 722 participants included in this analysis was 16.8 kg/m(2) during adolescence, while the median BMI as young adults was 19.3 kg/m(2). Lower aBMD during adulthood was associated with lower adolescent BMI (β (95 % confidence interval) for hip aBMD 0.017 (0.013 to 0.022) and LS aBMD 0.012 (0.008 to 0.016)). This association was attenuated upon adjustment for current fat and lean mass (β (95 % CI) for hip aBMD 0.00 (-0.005 to 0.005) and LS aBMD 0.005 (0.000 to 0.01)). There was clear evidence for positive associations between aBMDs and current lean mass.

CONCLUSIONS

Current lean mass was a more important determinant of bone mass than thinness during adolescence in this population. Weight gain during late adolescence and young adulthood coupled with improvement in lean mass may help to mitigate any adverse effects that pre-adulthood undernutrition may have on bone mass accrual.

1H-NMR analysis of the human urinary metabolome in response to an 18-month multi-component exercise program and calcium–vitamin-D3supplementation in older men

The musculoskeletal benefits of calcium and vitamin-D3supplementation and exercise have been extensively studied, but the effect on metabolism remains contentious. Urine samples were analyzed by1H-NMR spectroscopy from participants recruited for an 18-month, randomized controlled trial of a multi-component exercise program and calcium and vitamin-D3fortified milk consumption. It was shown previously that no increase in musculoskeletal composition was observed for participants assigned to the calcium and vitamin-D3intervention, but exercise resulted in increased bone mineral density, total lean body mass, and muscle strength. Retrospective metabolomics analysis of urine samples from patients involved in this study revealed no distinct changes in the urinary metabolome in response to the calcium and vitamin-D3intervention, but significant changes followed the exercise intervention, notably a reduction in creatinine and an increase in choline, guanidinoacetate, and hypoxanthine (p < 0.001, fold change > 1.5). These metabolites are intrinsically involved in anaerobic ATP synthesis, intracellular buffering, and methyl-balance regulation. The exercise intervention had a marked effect on the urine metabolome and markers of muscle turnover but none of these metabolites were obvious markers of bone turnover. Measurement of specific urinary exercise biomarkers may provide a basis for monitoring performance and metabolic response to exercise regimes.

Enhanced bone mass and physical fitness in prepubescent basketball players

The aim of this study was to examine the effect of basketball practice on bone acquisition in the prepubertal age. In total, 48 prepubescent male basketball players aged 11.1 ± 0.8 yr, Tanner stage 1, were compared with 50 controls matched for age and pubertal stage. Areal bone mineral density, bone mineral content (BMC), and bone area (BA) in deferent sites associated with anthropometric parameters were measured by dual-energy X-ray absorptiometry. Running and jumping tests were performed. Analysis of Student's impaired t-test revealed that basketball players attained better results in all physical fitness tests (p < 0.05). They also exhibited significantly greater BMC and BA in whole body, upper and lower extremities, trochanter, total hip, and whole right and left radius (p < 0.001) compared with the controls. No significant differences were observed between groups in right and left ultradistal and third distal radius and spinal regions, BMC, and BA, whereas a significant positive correlation was reported between lean mass, BMC, and BA of lower limbs. In summary, basketball practice in prepubertal age is associated with improved physical fitness and enhanced lean and bone mass in loaded sites.

Is bone tissue really affected by swimming? A systematic review

Background

Swimming, a sport practiced in hypogravity, has sometimes been associated with decreased bone mass.

Aim

This systematic review aims to summarize and update present knowledge about the effects of swimming on bone mass, structure and metabolism in order to ascertain the effects of this sport on bone tissue.

Methods

A literature search was conducted up to April 2013. A total of 64 studies focusing on swimmers bone mass, structure and metabolism met the inclusion criteria and were included in the review.

Results

It has been generally observed that swimmers present lower bone mineral density than athletes who practise high impact sports and similar values when compared to sedentary controls. However, swimmers have a higher bone turnover than controls resulting in a different structure which in turn results in higher resistance to fracture indexes. Nevertheless, swimming may become highly beneficial regarding bone mass in later stages of life.

Conclusion

Swimming does not seem to negatively affect bone mass, although it may not be one of the best sports to be practised in order to increase this parameter, due to the hypogravity and lack of impact characteristic of this sport. Most of the studies included in this review showed similar bone mineral density values in swimmers and sedentary controls. However, swimmers present a higher bone turnover than sedentary controls that may result in a stronger structure and consequently in a stronger bone.

Evaluation of the effect of glucosamine administration on biomarkers of cartilage and bone metabolism in bicycle racers

In the present study, the effect of glucosamine administration (1.5 or 3 g/day) on cartilage and bone metabolism was investigated in bicycle racers, using cartilage‑ and bone‑specific biomarkers, including C‑terminal cross‑linked telopeptides of type II collagen (CTX‑II), C‑terminal propeptides of type II procollagen (CPII), N‑terminal telopeptides of bone‑specific type I collagen (NTx) and bone alkaline phosphatase (BAP). The results indicate that CPII (a marker of type II collagen synthesis) was not substantially changed, however, CTX‑II (a marker of type II degradation) was reduced by glucosamine administration, particularly at a dose of 3 g/day. Consistent with these observations, the ratio of CTX‑II/CPII was reduced by glucosamine administration and the effect of glucosamine was dose‑dependent. By contrast, the levels of NTx (a bone resorption marker) and BAP (a bone formation marker) were not altered by glucosamine administration. A previous study by this group reported that glucosamine exerts a chondroprotective action in soccer players by preventing type II collagen degradation but maintaining type II collagen synthesis. Together these observations indicate that glucosamine may exert a chondroprotective action by preventing type II collagen degradation in athletes of various sports, including soccer players and bicycle racers.

Mechanical loading with or without weight-bearing activity: influence on bone strength index in elite female adolescent athletes engaged in water polo, gymnastics, and track-and-field

Bone health is considered not to benefit from water-based sports because of their weight-supported nature, but available evidence primarily relies on DXA technology. Our purpose was to investigate musculoskeletal health in the upper and lower body in well-trained adolescent female athletes using pQCT and compare these athletes with less-active, age- and sex-matched peers. Bone mineral content, volumetric cortical and trabecular BMD, total and cortical area, and bone strength index were assessed at the distal and proximal tibia and radius in four groups of adolescent females (mean age, 14.9 years) including water polo players (n = 30), gymnasts (n = 25), track-and-field athletes (n = 34), and nonactive controls (n = 28). Water polo players did not show any benefit in bone strength index or muscle size in the lower leg when compared with controls. In contrast, gymnasts showed 60.1 % and 53.4 % greater bone strength index at the distal and proximal tibia, respectively, than nonactive females (p < 0.05). Similarly, track-and-field athletes displayed 33.9 % and 14.7 % greater bone strength index at the distal and proximal tibia, respectively, compared with controls (p < 0.05). In the upper body, water polo players had 31.9 % greater bone strength index at the distal radius, but not the radial shaft, and 15.2 % larger forearm muscle cross-sectional area than controls (p < 0.05). The greatest musculoskeletal benefits in the upper body were found in gymnasts. In conclusion, despite training at an elite level, female water polo players did not show any benefits in musculoskeletal health in the lower leg and only limited benefits in the upper body when compared with nonactive girls.