Bone mineral density across a range of physical activity volumes: NHANES 2007-2010

A Comprehensive Analysis of Bone Mineral Density Changes across the Lifespan: Insights from National Surveys

BACKGROUND

There is limited research providing an overall understanding of bone mineral density (BMD) changes throughout different stages of life. This study aimed to investigate the pattern of BMD changes across childhood, adolescence, adulthood, and old age, as well as exploring the critical time of peak BMD (PBMD).

METHODS

Participants of three major ethnicities from National Health and Nutrition Examination Survey 1999 to 2018 were involved: 46,381 and 20,944 participants aged 8-85 years old were included in the Lumbar spine BMD (LSBMD) and femoral neck BMD (FNBMD) studies, respectively. BMD was measured using dual-energy X-ray absorptiometry. The generalized additive model was used to construct smoothed percentile curves.

RESULTS

Both males and females experienced a sharp increase in LSBMD during puberty, with females reaching their PBMD earlier than males. Females' LSBMD remained higher than males' before the age of approximately 50, except for Non-Hispanic Blacks. For males, LSBMD reached a plateau at around 30 years old after reaching the peak value. Females exhibited two peak points on the fitted curves, with the second PBMD occurring around 36-37 years old. Ethnic variations were observed, with Non-Hispanic Blacks displaying the highest BMD levels at all ages. Non-Hispanic Whites and Mexican Americans had lower BMD levels, with Mexican Americans generally exhibiting the lowest BMD. FNBMD reached its peak earlier than LSBMD, and males consistently had higher FNBMD than females.

CONCLUSIONS

This nationally representative study contributes to the understanding of BMD changes across the lifespan, and might provide guidance for bone health interventions in different population groups.

Race and ethnic differences in physical activity, osteopenia, and osteoporosis: results from NHANES 2009-2010, 2013-2014, 2017-2018

This study aimed to determine current physical activity trends association with bone density in a racial and ethnically diverse sample of older adults. We found that those engaged in no and some physical activity had lower femoral BMD when compared to those that met the physical activity recommendation.

PURPOSE

Most older adults do not engage in the recommended levels of physical activity to improve health, and there are racial and ethnic differences in physical activity participation. This study aims to evaluate whether meeting the physical activity recommendation is related to osteopenia and osteoporosis in a racially and ethnically diverse sample of older adults.

METHODS

Femoral neck bone mineral density (BMD) data from the National Health and Nutrition Examination Survey (NHANES 2009-2010, 2013-2014, 2017-2018) was obtained from 5252adults 60-80 years old. Self-reported physical activity was categorized into met recommendation, some physical activity, and no physical activity. We used linear regression models to examine the association between physical activity and BMD for each race and ethnic group adjusting for sociodemographics and other selected variables.

RESULTS

Non-Latino Blacks (NLB) and Latinos reported the lowest prevalence of meeting the physical activity recommendation, compared with Non-Latino Whites (NLW) (40.0%, 44.0%, and 51.4%, respectively; p < 0.0001). Further, NLB and Latinos had a lower prevalence of osteoporosis when compared to NLW (5.4%, 7.3%, and 9.1% respectively; p < 0.0001). There was a 0.03 g/cm2 difference in BMD between those who met the physical activity recommendation when compared to the no physical activity group; however, this decreased after adjusting for selected covariates.

CONCLUSION

Considering the prevalence and burden of osteopenia and osteoporosis, and projected increases in the racial and ethnic diversity of the older population, more research is needed to further understand the association between meeting the physical activity recommendation and bone health among racial and ethnic diverse older adults.

The effects of community-based exercise modalities and volume on musculoskeletal health and functions in elderly people

The effects of different muscle loading exercise (MLEX) modes and volume on musculoskeletal health is not well-studied in older populations. Aim: Therefore, this study aimed to compare the effects of community-based MLEX modalities and volume on musculoskeletal health in elderly people. Methods: Elderly men (n = 86) and women (n = 170), age 50-82 years old, were assigned to the sedentary (SE, n = 60), muscle strengthening exercise (MSE, n = 71), aerobic exercise (AE, n = 62) and Tai Chi exercise (TCE, n = 63) groups, based on > 2 years of exercise history. Exercise volume was compared between "Minimum" ("Min" < 60 min/week), "Low" (60-120 min/week). "Moderate" (121-239 min/week) and "High" (240-720 min/week) volumes. Results: All three modes of MLEX were associated with lower percentage of body fat (BF%) and higher percentage of lean body mass (LBM%, p = 0.003 main effect of group, and p = 0.002 main effect of volume for both BF% and LBM%), but not with higher bone mineral density (BMD, total body, lumbar spine, total hip and neck of femur), than SE. TCE had a distinct advantage in trunk flexibility (p = 0.007 with MSE, p = 0.02 with AE, and p = 0.01 with SE), and both TCE (p = 0.03) and AE (p = 0.03) performed better than SE in the one-leg stand balance test. Isometric strength and throwing speed and peak power with a 2 kg power ball were higher in the MLEX than SE groups (p = 0.01), in the ranking order of MSE, AE and TCE. However, there was no difference in handgrip strength performance between the MLEX groups, which performed better than the SE participants. Accumulating >120 min/week of MLEX can promote body composition health and muscle functions, but 60 min/week of MSE alone may have equal or better outcomes in these parameters. Conclusion: Community-based MLEX classes may be used to mitigate age-related chronic disease that are associated with body composition and muscular functions.

Physical activity as a causal variable for adolescent resilience levels: A cross-lagged analysis

This study extends research on the relationship between physical activity and adolescent resilience by using cross-lagged analysis. Therefore, it used the Adolescent Resilience Rating Scale and the Physical Activity Scale to conduct a one-year longitudinal follow-up survey on 818 adolescents (50.6% boys), aged 12-17. They completed the questionnaires, providing data on physical activity and adolescent resilience. The results indicated there were significant gender differences in physical activity, but there was no significant gender difference in adolescent resilience; there was a significant positive correlation between physical activity and adolescent resilience; physical activity had a significant predictive effect on adolescent resilience. This study supports the assertion that physical activity has an important impact on adolescent resilience. It further analyzes the possible reasons for this result and contemplates the theoretical and practical significance of the findings, which provides evidence for the study of adolescents' physical and mental health and enriches the theory of resilience.

Longitudinal Associations of High-Volume and Vigorous-Intensity Exercise With Hip Fracture Risk in Men

Maintenance of vigorous exercise habits from young to old age is considered protective against hip fractures, but data on fracture risk in lifelong vigorous exercisers are lacking. This longitudinal cohort study examined the hazard of hip fractures in 1844 male former athletes and 1216 population controls and in relation to exercise volume and intensity in later years. Incident hip fractures after age 50 years were identified from hospital discharge register from 1972 to 2015. Exercise and covariate information was obtained from questionnaires administered in 1985, 1995, 2001, and 2008. Analyses were conducted using extended proportional hazards regression model for time-dependent exposures and effects. During the mean ± SD follow-up of 21.6 ± 10.3 years, 62 (3.4%) athletes and 38 (3.1%) controls sustained a hip fracture. Adjusted hazard ratio (HR) indicated no statistically significant difference between athletes and controls (0.84; 95% confidence interval [CI], 0.55-1.29). In subgroup analyses, adjusted HRs for athletes with recent high (≥15 metabolic equivalent hours [MET-h]/week) and low (<15 MET-h/week) exercise volume were 0.83 (95% CI, 0.46-1.48) and 1.04 (95% CI, 0.57-1.87), respectively, compared with controls. The adjusted HR was not statistically significant between athletes with low-intensity exercise (<6 METs) and controls (1.08; 95% CI, 0.62-1.85). Athletes engaging in vigorous-intensity exercise (≥6 METs at least 75 minutes/week) had initially 77% lower hazard rate (adjusted HR 0.23; 95% CI, 0.06-0.86) than controls. However, the HR was time-dependent (adjusted HR 1.04; 95% CI, 1.01-1.07); by age 75 years the HRs for the athletes with vigorous-intensity exercise reached the level of the controls, but after 85 years the HRs for these athletes increased approximately 1.3-fold annually relative to the controls. In conclusion, these data suggest that continuation of vigorous-intensity exercise is associated with lower HR of hip fracture up to old age. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Investigation of the Relationship Between Peak Vertical Accelerations and Aerobic Exercise Intensity During Graded Walking and Running in Postmenopausal Women

How exercise intensity targets, calibrated according to oxygen consumption, relate to vertical impacts during weight-bearing exercise is currently unknown. The authors investigated the relationship between vertical peaks (VPs) and metabolic equivalents (METs) of oxygen consumption in 82 women during walking and running. The magnitude of VPs, measured using a hip-worn triaxial accelerometer, was derived from recommended aerobic exercise intensity targets. VPs were 0.63 ± 0.18g at the lower recommended absolute exercise intensity target (3 METs) but >1.5g at the upper end of moderate-intensity activities (1.90 ± 1.13g at 6 METs). Multilevel linear regression analyses identified speed and type of locomotion as the strongest independent predictors of VPs, explaining 54% and 11% of variance, respectively. The authors conclude that, in contrast to lower intensities, exercising close to or above the 6-MET threshold generates VPs of osteogenic potential, suggesting this could provide simultaneous benefits to decrease all-cause mortality and osteoporosis risk.

Dominant vs. non-dominant hip comparison in bone mineral density in young sporting athletes

To explore differences in bone mineral density (BMD) between dominant and non-dominant hip within levels of sport impact. BMD was higher in the non-dominant hip in high-impact sports, whereas the dominant hip had increased BMD for low-impact sports. The side-to-side differences were relatively small and not clinically relevant.

PURPOSE

It is unknown whether there is difference in BMD at the hip between dominant and non-dominant sides in young athletes. The aims of this study were to explore the dominant-non-dominant differences in hip BMD in young athletes participating in low- and high-impact sports and to assess the effect of ground force impact on BMD.

METHODS

Data was collected on University of Oxford athletes and controls (CG) between 2016 and 2018. Athletes were classified into two groups: high-impact sports (HIG) and low-impact sports (LIG). Total and regional measurements of both hips' BMD were recorded using a dual-energy X-ray absorptiometry (DXA). Linear regression method was used to assess differences in BMD between and within groups.

RESULTS

One hundred ninety-four athletes (HIG: n = 89, LIG: n = 105) and 48 controls were included in this study. Total hip and femoral neck BMD was higher in athletes compared to the CG (p < 0.01), with HIG recording highest levels of BMD. The BMD difference between the dominant and non-dominant sides was significant in the LIG, with BMD being higher in the dominant side. Conversly, BMD was higher in the non-dominant hip within the HIG. However, the hip asymmetries were not clinically relevant (%BMD difference < 3%). A significant interaction between side and sport group on BMD was observed.

CONCLUSIONS

High-impact sports had significantly higher BMD compared with low-impact sports and CG. BMD in the dominant hip was significantly higher for the LIG and lower in the HIG; however, differences were not clinically relevant.

The effect of running on foot muscles and bones: A systematic review

Despite the widespread evidence of running as a health-preserving exercise, little is known concerning its effect on the foot musculature and bones. While running may influence anatomical foot adaptation, it remains unclear to what extent these adaptations occur. The aim of this paper is to provide a systematic review of the studies that investigated the effects of running and the adaptations that occur in foot muscles and bones. The search was performed following the PRISMA guidelines. Relevant keywords were used for the search through PubMed/MEDLINE, Scopus and SPORTDiscus. The methodological quality of intervention studies was assessed using the Downs and Black checklist. For cross-sectional studies, the Newcastle-Ottawa scale was used. Sixteen studies were found meeting the inclusion criteria. In general, the included studies were deemed to be of moderate methodological quality. Although results of relevant literature are limited and somewhat contradictory, the outcome suggests that running may increase foot muscle volume, muscle cross-sectional area and bone density, but this seems to depend on training volume and experience. Future studies conducted in this area should aim for a standard way of reporting foot muscle/bone characteristics. Also, herein, suggestions for future research are provided.

The interactions of physical activity, exercise and genetics and their associations with bone mineral density: implications for injury risk in elite athletes

Low bone mineral density (BMD) is established as a primary predictor of osteoporotic risk and can also have substantial implications for athlete health and injury risk in the elite sporting environment. BMD is a highly multi-factorial phenotype influenced by diet, hormonal characteristics and physical activity. The interrelationships between such factors, and a strong genetic component, suggested to be around 50-85% at various anatomical sites, determine skeletal health throughout life. Genome-wide association studies and case-control designs have revealed many loci associated with variation in BMD. However, a number of the candidate genes identified at these loci have no known associated biological function or have yet to be replicated in subsequent investigations. Furthermore, few investigations have considered gene-environment interactions-in particular, whether specific genes may be sensitive to mechanical loading from physical activity and the outcome of such an interaction for BMD and potential injury risk. Therefore, this review considers the importance of physical activity on BMD, genetic associations with BMD and how subsequent investigation requires consideration of the interaction between these determinants. Future research using well-defined independent cohorts such as elite athletes, who experience much greater mechanical stress than most, to study such phenotypes, can provide a greater understanding of these factors as well as the biological underpinnings of such a physiologically "extreme" population. Subsequently, modification of training, exercise or rehabilitation programmes based on genetic characteristics could have substantial implications in both the sporting and public health domains once the fundamental research has been conducted successfully.

Objectively measured absolute and relative physical activity intensity levels in postmenopausal women

OBJECTIVES

To investigate how objectively measured physical activity (PA) levels differ according to absolute moderate intensity recommendation (3-6 METs) and relative to individual lactate thresholds (LT1 and LT2), and to verify if high-fit women record higher PA levels compared to women with lower aerobic fitness.

METHODS

Seventy-five postmenopausal women performed an incremental exercise test and several constant-velocity tests wearing an accelerometer to identify the activity counts (ct min^-1) corresponding to LT1 and LT2. Individual linear regression determined activity counts cut-points for each intensity: (1) sedentary (<200 ct min^-1), (2) light (from 200 ct min^-1 to ct min^-1 at LT1), (3) moderate (ct min^-1 between LT1 and LT2) and (4) vigorous (ct min^-1> LT2). Participants then wore an accelerometer during a week to measure the time spent at each PA intensity level.

RESULTS

According to absolute intensity categorisation, high-fit postmenopausal women recorded twice as much time at moderate-to-vigorous PA (MVPA) (P < 0.01) than low-fit women. However, when PA intensity was calculated relative to individual lactate thresholds, MVPA was significantly reduced by half (P < 0.01) and the data revealed no differences (P = 0.62) between groups (∼20 min day^-1 at MVPA).

CONCLUSIONS

Accelerometer cut-points derived from absolute moderate-intensity recommendations overestimated MVPA. Similar time at MVPA was recorded by high- and low-fit postmenopausal women when the cut-points were tailored to individual lactate thresholds. A more accurate estimation of PA behaviour could be provided with the use of individually tailored accelerometer cut-points.

High-impact exercise in adulthood and vertebral dimensions in midlife - the Northern Finland Birth Cohort 1966 study

Background

Vertebral size and especially cross-sectional area (CSA) are independently associated with vertebral fracture risk. Previous studies have suggested that physical activity and especially high-impact exercise may affect vertebral strength. We aimed to investigate the association between high-impact exercise at 31 and 46 years of age and vertebral dimensions in midlife.

Methods

We used a subsample of 1023 individuals from the Northern Finland Birth Cohort 1966 study with records of self-reported sports participation from 31 and 46 years and MRI-derived data on vertebral dimensions from 46 years. Based on the sports participation data, we constructed three impact categories (high, mixed, low) that represented longitudinal high-impact exercise activity in adulthood. We used linear regression and generalized estimating equation (GEE) models to analyse the association between high-impact exercise and vertebral CSA, with adjustments for vertebral height and body mass index.

Results

Participation in high-impact sports was associated with large vertebral CSA among women but not men. The women in the 'mixed' group had 36.8 (95% confidence interval 11.2–62.5) mm² larger CSA and the women in the 'high' group 43.2 (15.2–71.1) mm² larger CSA than the 'low' group.

Conclusions

We suggest that participation (≥ 1/week) in one or more high-impact sports in adulthood is associated with larger vertebral size, and thus increased vertebral strength, among middle-aged women.

Effects of Leisure-Time Physical Activity on Vertebral Dimensions in the Northern Finland Birth Cohort 1966

Vertebral fractures are a common burden amongst elderly and late middle aged people. Vertebral cross-sectional area (CSA) is a major determinant of vertebral strength and thus associated with vertebral fracture risk. Previous studies suggest that physical activity affects vertebral CSA. We aimed to investigate the relationship between leisure-time physical activity (LTPA) from adolescence to middle age and vertebral dimensions in adulthood. We utilized the Northern Finland Birth Cohort 1966, of which 1188 subjects had records of LTPA at 14, 31 and 46 years, and had undergone lumbar magnetic resonance imaging (MRI) at the mean age of 47 years. Using MRI data, we measured eight dimensions of the L4 vertebra. Socioeconomic status, smoking habits, height and weight were also recorded at 14, 31 and 46 years. We obtained lifetime LTPA (14-46 years of age) trajectories using latent class analysis, which resulted in three categories (active, moderately active, inactive) in both genders. Linear regression analysis was used to analyze the association between LTPA and vertebral CSA with adjustments for vertebral height, BMI, socioeconomic status and smoking. High lifetime LTPA was associated with larger vertebral CSA in women but not men. Further research is needed to investigate the factors behind the observed gender-related differences.

2015 Guidelines for Osteoporosis in Saudi Arabia: Recommendations from the Saudi Osteoporosis Society

BACKGROUND AND OBJECTIVES

To provide guidelines for medical professionals in Saudi Arabia regarding osteoporosis.

DESIGN AND SETTINGS

A panel of 14 local experts in osteoporosis assembled to provide consensus based on the strength of evidence and expert opinions on osteoporosis treatment.

PATIENTS AND METHODS

The Saudi Osteoporosis Society (SOS) formed a panel of experts who performed an extensive published studies search to formulate recommendations regarding prevention, diagnosis, and treatment of osteoporosis in Saudi Arabia. Both local and international published studies were utilized whenever available.

RESULTS

Dual x-ray absorptiometry (DXA) scanning is still the golden standard for assessing bone mineral density (BMD). In the absence of local, country-specific fracture risk assessment tool (FRAX), the SOS recommends using the USA (White) version of the FRAX tool. All women above 60 years of age should be evaluated for BMD. This is because the panel recognized that osteoporosis and osteoporotic fractures occur at a younger age in Saudi Arabia. Hormone replacement therapy (HRT) is not recommended for treating postmenopausal women with osteoporosis. BMD evaluation should be performed 1-2 years after initiating intervention, and the assessment of bone turnover biomarkers should be performed whenever available to determine the efficacy of intervention.

CONCLUSION

All Saudi women above the age of 60 years must undergo a BMD assessment using DXA. Therapy decisions should be formulated with the use of the USA (White) version of the FRAX tool.