Body composition assessment in the prediction of osteoporotic fractures

Body Composition Prediction-BOMP: A New Tool for Assessing Fat and Lean Body Mass

BACKGROUND

Pragmatic and easy-to-use alternatives to estimating body composition, such as lean body mass and fat mass, could be valuable tools for assessing the risk of diabetes or other metabolic diseases. Previous work has shown how demographic and anthropometric data could be used in a neural network to estimate body composition with high precision. However, there is still a need for a publicly available and user-friendly format before these results can have clinical impact.

METHODS

We used data from 18 430 NHANES participants and stepwise linear regression with inclusion of linear, interactions, and quadratic terms to model lean body and fat mass. HTML and Javascript was used to develop a webapp as a frontend of the model.

RESULTS

The models had a correlation cofficent R = 0.99-0.98 (P < .001) withstandard error of estimate [SEE] = 2.07-2.05.

CONCLUSIONS

The results indicate that it is possible to develop a "white-box" model with high precision.The proof of concept webapp is available as open source under the MIT license.

Interaction Effect of Phase Angle and Age on Femoral Neck Bone Mineral Density in Patients with Non-Dialysis Chronic Kidney Disease Stage 5

Background: Low bone mass is common in malnourished patients with chronic kidney disease (CKD) and can lead to a higher risk of fractures. Elderly and CKD patients have the same risk factors for protein-energy wasting, sarcopenia, and osteoporosis. Here, we investigated the association between phase angle (PhA) and bone mineral density (BMD) in dialysis-naïve patients with CKD stage 5 (CKD5) and identified a statistical relationship between PhA and age, which affects bone density. Methods: Bio-impedance spectroscopy for evaluating body composition and PhA and dual-energy X-ray absorptiometry for determining the BMD were simultaneously performed in 167 consecutive patients (mean age, 59.65 ± 13.98 years; women, 40.1%). Two-way analysis of variance (ANOVA) was conducted to assess the potential interaction effect of PhA and age on femoral neck BMD (FN-BMD). Results: Our results showed that PhA and age were independently associated with FN-BMD and T-score in multiple linear regressions analyses. A significant interaction effect of PhA and age on FN-BMD was found on two-way ANOVA (p = 0.028). The average BMD values for the first and second tertiles of the PhA were higher in the young versus elderly group, whereas patients in the elderly group had higher BMD in the third tertiles. Conclusions: A relationship was noted between PhA and BMD in patients with advanced-stage CKD. The effect of PhA level on FN-BMD differed between elderly and young patients. Our study suggested that higher PhA levels could be a marker explaining the maintenance of good bone health in elderly patients with CKD5. Further longitudinal analyses are needed to determine whether PhA predicts the risk of CKD-MBD-related fractures during CKD progression.

Menopause-Related Changes in Body Composition Are Associated With Subsequent Bone Mineral Density and Fractures: Study of Women's Health Across the Nation

During the menopause transition (MT), lean mass decreases and fat mass increases. We examined the associations of these body composition changes during the MT (2 years before to 2 years after the final menstrual period) with bone mineral density (BMD) at the end of the MT and fracture after the MT. We included 539 participants from the Study of Women's Health Across the Nation who were not taking bone-beneficial or bone-detrimental medications before or during the MT. Using multivariable linear regression, we assessed the independent associations of % lean mass loss and % fat mass gain during the MT (mutually adjusted) with femoral neck (FN) and lumbar spine (LS) BMD at the end of the MT, adjusted for pre-MT BMD, pre-MT lean and fat mass, race/ethnicity, Study of Women's Health Across the Nation (SWAN) study site, age, and cigarette use. We used Cox proportional hazards regression to quantify the relations of % lean loss and % fat gain during the MT with fracture after the MT. The Cox model was adjusted for the covariates above plus post-MT use of bone-detrimental medications, and censored at the first use of bone-beneficial medications; we further controlled for FN or LS BMD at the end of the MT. Adjusted for covariates, each standard deviation (SD) (6.9%) increment in lean mass loss was associated with 0.010 g/cm2 lower FN BMD (p < 0.0001); each SD (19.9%) increment in fat mass gain was related to 0.026 g/cm2 greater FN (p = 0.009) and LS (p = 0.03) BMD. Each SD increment in lean mass loss and fat mass gain was associated with 63% (p = 0.001) and 28% (p = 0.05) greater fracture hazard after the MT; associations were essentially unchanged by BMD adjustment. MT-related lean mass loss and fat mass gain were associated differentially with BMD; both were independently related to more fractures. Mitigating MT-related body composition changes may reduce fracture risk. © 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).

Causal associations of hand grip strength with bone mineral density and fracture risk: A mendelian randomization study

BACKGROUND

Muscle strength has been shown to exert positive effects on bone health. The causal relationship between hand grip strength and osteoporosis is an important public health issue but is not fully revealed. The goal of this study was to investigate whether and to what extent hand grip strength affects bone mineral density (BMD) and fracture risk.

METHODS

We conducted a state-of-the-art two-sample Mendelian randomization analysis. Genomewide significant (P<5×10^-8) single nucleotide polymorphisms associated with hand grip strength were obtained. Summary level data of BMD and fractures at different body sites (lumbar spine, heel, forearm and femoral neck) was obtained from a large-scale osteoporosis database. The inverse variance weighted method was the primary method used for analysis, and the weighted-median, MR-Egger were utilized for sensitivity analyses.

RESULTS

The results provided strong evidence that hand grip strength trait was causally and positively associated with lumbar spine BMD (β: 0.288, 95% CI: 0.079 to 0.497; P=0.007), while no causal relationship was found between hand grip strength and BMD at heel (β: -0.081, 95% CI: -0.232 to 0.070; P=0.295), forearm (β: 0.-0.101, 95% CI: -0.451 to 0.248; P=0.571) or femoral neck (β: 0.054, 95% CI: -0.171 to 0.278; P=0.639). In addition, no statistically significant effects were observed for hand grip strength on fracture risks (β: -0.004, 95% CI: -0.019 to 0.012; P=0.662).

CONCLUSIONS

This study showed a positive causal relationship between hand grip strength and lumbar BMD, which is the most common site of osteoporotic fracture, but did not find a causal relationship between hand grip strength and BMD of heel, forearm, or femoral neck. No statistically significant effect of hand grip strength on fracture risk was observed. This study indicates variations in the abilities of hand grip strength trait to causally influence BMD at different skeleton sites. These results should be considered in further studies and public health measures on osteoporosis prevention strategies.

Precise Prediction of Total Body Lean and Fat Mass From Anthropometric and Demographic Data: Development and Validation of Neural Network Models

BACKGROUND

Estimating body composition is relevant in diabetes disease management, such as drug administration and risk assessment of morbidity/mortality. It is unclear how machine learning algorithms could improve easily obtainable body muscle and fat estimates. The objective was to develop and validate machine learning algorithms (neural networks) for precise prediction of body composition based on anthropometric and demographic data.

METHODS

Cross-sectional cohort study of 18 430 adults and children from the US population. Participants were examined with whole-body dual X-ray absorptiometry (DXA) scans, anthropometric assessment, and answered a demographic questionnaire. The primary outcomes were predicted total lean body mass (_predLBM), total body fat mass (_predFM), and trunk fat mass (_predTFM) compared with reference values from DXA scans.

RESULTS

Participants were randomly partitioned into 70% training (12 901) data and 30% validation (5529) data. The prediction model for _predLBM compared with lean body mass measured by DXA (_DXALBM) had a Pearson's correlation coefficient of R = 0.99 with a standard error of estimate (SEE) = 1.88 kg (P < .001). The prediction model for _predFM compared with fat mass measured by DXA (_DXAFM) had a Pearson's coefficient of R = 0.98 with a SEE = 1.91 kg (P < .001). The prediction model for _predTFM compared with DXA measured trunk fat mass (_DXAFM) had a Pearson's coefficient of R = 0.98 with a SEE = 1.13 kg (P < .001).

CONCLUSIONS

In this study, neural network models based on anthropometric and demographic data could precisely predict body muscle and fat composition. Precise body estimations are relevant in a broad range of clinical diabetes applications, prevention, and epidemiological research.

Accelerated decline in quadriceps area and Timed Up and Go test performance are associated with hip fracture risk in older adults with impaired kidney function

OBJECTIVE

This study aimed to examine whether an accelerated decline in quadriceps cross-sectional area (CSA), attenuation (a surrogate of quality), and strength, as well as lower limb muscular function, are associated with hip fractures in older adults with impaired kidney function.

DESIGN

Prospective population-based study.

SETTING

Community-dwelling old population in Reykjavik, Iceland.

SUBJECTS

A total of 875 older adults (mean baseline age 76 years) from the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study with impaired kidney function.

METHODS

Quadriceps CSA and density were determined using computed tomography (CT), knee extension strength was measured with an isometric dynamometer chair, and muscular function was assessed using the Timed Up and Go (TUG) test. All muscle-related measurements were assessed twice over a mean follow-up of 5.2 years. Data on hip fracture incidence was obtained from medical records during a maximum of 8.4 years of follow-up time.

RESULTS

Fully adjusted cox-proportional hazard regression models showed that a faster decline in quadriceps CSA and TUG test performance were significantly associated with increased hip fracture risk (HR = 1.55, 95% CI = 1.02-2.36, and HR = 1.80, 95% CI = 1.19-2.72, respectively). A faster decrease in quadriceps density and isometric knee extension strength were not associated with fracture risk.

CONCLUSIONS

Accelerated decline in CT-derived quadriceps CSA and muscular function, as measured by the TUG test's performance, are predictive of hip fracture risk in older adults with impaired kidney function. TUG test is a simple measure and easily included in routine medical examinations, compared to CT scans, which seems to be useful for identifying a subgroup of individuals with high risk of fracture.

Anticonvulsant use and bone health in a population-based study of men and women: cross-sectional data from the Geelong Osteoporosis Study

Background

Anticonvulsant use has been linked to bone deficits in specific patient populations. We studied the association between anticonvulsant use and bone health in a population-based sample of men and women.

Methods

Data from 926 men (24-73 yr) and 1070 women (21-94 yr) participating in the Geelong Osteoporosis Study were included. Bone mineral density (BMD, g/cm²) of the PA-spine and total hip was measured using dual-energy X-ray absorptiometry (Lunar). Bone quality was determined using quantitative heel ultrasound (QUS). Anthropometry was conducted and socioeconomic status was determined. Medication and lifestyle information was obtained via questionnaire. Linear regression was used to test associations between anticonvulsant use and bone health before and after adjustment for potential confounders.

Results

Seventeen (1.8%) men and 20 (1.9%) women reported anticonvulsant use. In men, anticonvulsant users had 9.1% lower adjusted mean BMD at the spine and hip compared to non-users. Body mass index was an effect modifier at the spine. Anticonvulsant users also had 1.8% lower speed of sound (SOS), 10.6% lower broadband ultrasound attenuation (BUA) and 13.7% lower stiffness index (SI) compared to non-users. In women, BMD tended to be lower at the hip compared to non-users as with the bone quality measure, BUA. No significant associations were observed at the spine or the other bone quality measures, SOS and SI.

Conclusion

Our data suggest that bone quantity and quality, assessed using BMD and QUS, are lower for men and possibly women who use anticonvulsants. While further exploration into potential mechanisms is needed, our findings suggest that monitoring bone health among users of anticonvulsants is warranted.

Lifestyle and Environmental Factors Affecting Bone Mass in Japanese Female Adolescents

PURPOSE

A higher peak bone mass (PBM) in adolescence lowers the risk of osteoporosis later in life. This study examined the factors affecting bone mass in female adolescents in relation to lifestyle and environmental factors to promote bone mass development before reaching PBM.

DESIGN AND METHODS

The subjects were female students aged 15-16 years and their mothers at a public high school in Osaka, Japan. Bone mass was measured using quantitative ultrasound parameters. The body composition was measured using a multi-frequency segmental body composition analyzer. Nutrient intake, exercise habits, and maternal factors as environmental factors were examined using a questionnaire.

RESULTS

Logistic regression analyses revealed that the adolescents' lean mass was significantly related to the BUA (p < .05). The adjusted odds ratio was 1.29 (95% confidence interval [CI]: 1.07-1.54). In contrast, the adolescents' exercise habit was significantly related to the SOS (p < .05). The SOS was significantly higher in the adolescents who exercised >4 times a week than in those who exercised <2-3 times a week. The adjusted odds ratio was 2.83 (95% CI: 1.06-7.56). The adolescents' nutrient intake and maternal factors were not significant factors affecting the adolescents' bone mass.

CONCLUSIONS

The present study suggests that increasing lean mass and exercising more than four times a week were important for increasing bone mass in female adolescents.

PRACTICE IMPLICATIONS

Nurses should intervene to help female adolescents acquire healthy lifestyle skills and maintain proper body composition and exercise habits to promote bone mass development before reaching PBM.

Transwomen and bone mineral density: a cross-sectional study in Brazilian population

OBJECTIVES

Transgender individuals submitted to hormone or surgical treatment may have alterations in their bone metabolism as these elements are important players in bone remodeling. We aimed to study bone mineral density (BMD) and body composition in transwomen undergoing cross-sex hormonal treatment (CSHT) from Brazil for over 3 years, comparing them with female and male controls.

METHODS

93 individuals (31 transwomen, 31 females and 31 males paired for age and body mass index) were studied for bone mass, and body composition by densitometry (by DXA). Epidemiological and clinical data were collected through direct questioning.

RESULTS

Low bone mass (T score ≤2) was found in 12.9% of transwomen; in 3.2% of females and 3.3% of males. Transwomen individuals had lower spine Z score (0.26 ± 1.42 vs 0.50 ± 1.19) and femur Z score (-0.41 ± 0.95 vs 0.29 ± 1.04) than females. They had lower total femur Z score than males (-0.41 ± 0.95 vs 0.20 ± 0.83). Lean mass values correlated positively with total femur BMD (ρ = 0.40; 95% confidence interval = 0.009-0.68; p = 0.04) and BMD in femoral neck (ρ = 0.48; 95% confidence interval = 0.11-0.74; p = 0.01) but neither the type of therapy received nor the time that they were used, impacted bone mass.

CONCLUSION

Low BMD is found frequently in transwomen and it is correlated with lean body mass.

ADVANCES IN KNOWLEDGE

There are few studies of the effects of hormone therapy on the bones and muscles of transwomen. This study demonstrated that significant changes occur, and that the population studied needs greater care in musculoskeletal health.

The Favorable Effects of a High-Intensity Resistance Training on Sarcopenia in Older Community-Dwelling Men with Osteosarcopenia: The Randomized Controlled FrOST Study

Purpose

Sarcopenia, the loss of muscle mass combined with the loss of muscle function, has become a public health issue. There is an urgent need for interventions. The study aimed to determine the effect of high-intensity resistance training (HI-RT), a time- and cost-efficient training modality, on sarcopenia in osteosarcopenic (OS) older men.

Methods

Forty-three community-dwelling men aged ≥72 years from Northern Bavaria, Germany, with OS were randomly assigned to either an active HI-RT group (HI-RT) or an inactive control group (CG). Both received dietary protein (up to 1.5 g/kg/day in HI-RT and 1.2 g/kg/day in CG) and Vitamin-D (up to 800 IE/d) supplements. The HI-RT was applied as a consistently supervised single-set training on resistance exercise machines using intensifying strategies, with two training sessions/week, structured into three phases (ranging from 8 to 12 weeks) totaling 28 weeks. The primary study endpoint was the Sarcopenia Z-score; secondary endpoints were changes in the underlying physiological parameters, skeletal muscle mass index (SMI), handgrip-strength and gait velocity.

Results

The results show a significant effect of the exercise intervention on the sarcopenia Z-score in the HI-RT (p<0.001) and a significant worsening of it in the CG (p=0.012) in the intention-to-treat analysis, as well as a significant intergroup change (p<0.001). Analysis upon the underlying parameters showed a significant increase of skeletal muscle mass index (SMI) in the HI-RT group (p<0.001) and a significant intergroup difference of SMI (p<0.001) and handgrip strength (p<0.001). There were no adverse effects related to dietary supplementation or training.

Conclusion

The results clearly confirm the favorable effects of HI-RT on sarcopenia. We conclude that HI-RT is a feasible, highly efficient and safe training modality for combating sarcopenia, also in the elderly.

Balance performance and related soft tissue components across three age groups

With the aging process, falls and related injuries are common and unwanted events among older women. Lost balance is the last step before the frequent experience of falls. After menopause, women's bone conditions regarding health and balance performance steeply decline often resulting in serious injury. Our purpose in the study is to identify balance performance and its associations with soft tissue components among Korean-American (KA) women with three menopausal conditions. Researchers conducted a cross-sectional study with 63 KA women divided into three age groups: 25-35 years (young), 45-55 years old (middle), and 65+ years (old). Lean and fat mass on the entire body, appendicular and gynoid areas were measured by using the dual X-ray absorptiometry. Static and dynamic balance and physical performance (floor sit to stand) were tested. We found that with increased aging, lean mass, fat and body mass index were changed; balance and physical performance decreased significantly. In regression models, age and fat ratio of android/gynoid changes explain static balance and physical performance; appendicular lean mass predicted dynamic balance. With advancing age, maintaining lean mass and proportion of fat accumulation is critical for stable balance.

The clinical impact and biological mechanisms of skeletal muscle aging

Skeletal muscle is a highly plastic tissue that remarkably adapts to diverse stimuli including exercise, injury, disuse, and, as discussed here, aging. Humans achieve peak skeletal muscle mass and strength in mid-life and then experience a progressive decline of up to 50% by the ninth decade. The loss of muscle mass and function with aging is a phenomenon termed sarcopenia. It is evidenced by the loss and atrophy of muscle fibers and the concomitant accretion of fat and fibrous tissue. Sarcopenia has been recognized as a key driver of limitations in physical function and mobility, but is perhaps less appreciated for its role in age-related metabolic dysfunction and loss of organismal resilience. Similar to other tissues, muscle is prone to multiple forms of age-related molecular and cellular damage, including disrupted protein turnover, impaired regenerative capacity, cellular senescence, and mitochondrial dysfunction. The objective of this review is to highlight the clinical consequences of skeletal muscle aging, and provide insights into potential biological mechanisms. In light of population aging, strategies to improve muscle health in older adults promise to have a profound public health impact.

Impact of cross-sex hormone therapy on bone mineral density and body composition in transwomen

OBJECTIVE

Cross-sex hormone therapy (CSHT) has been associated with changes in bone and lean/fat mass. This study assessed bone mineral density (BMD), appendicular lean mass (ALM), and total fat mass in transwomen undergoing CSHT.

PATIENTS AND DESIGN

We evaluated 142 transwomen (mean age: 33.7 ± 10.3 years; BMI: 25.4 ± 4.6; 86.6% with previous CSHT) during the first 3 months of regular oestrogen treatment (with or without anti-androgens). A reference group including 22 men and 17 cis women was also studied.

MEASUREMENTS

Clinical and hormonal evaluation and dual-energy X-ray absorptiometry (DXA).

RESULTS

Bone mineral density was similar in trans and reference women, and lower at all sites in transwomen vs men. Low bone mass for age was observed in 18% of transwomen at baseline vs none of the reference women or men. Appendicular lean mass and total fat mass were positively correlated with L1-L4 BMD, explaining 14.9% of the observed variation in lumbar spine BMD and 20.6% of the variation in total femur BMD. Appendicular lean mass was similar in trans and reference women, and lower in transwomen vs men. Total fat mass was lower in trans vs reference women. Densitometry was repeated after a mean of 31.3 ± 6.5 months in 46 transwomen. There was a significant increase in total fat mass and a significant decrease in ALM. Bone mineral density remained stable over time.

CONCLUSIONS

The fairly high prevalence of low bone mass in this sample of transwomen from southern Brazil seems to be related to lower ALM. Non-pharmacological lifestyle-related strategies for preventing bone loss could be beneficial for transgender women receiving long-term CSHT.

Physical Activity, Physical Fitness, Body Composition, and Nutrition Are Associated with Bone Status in University Students

Understanding the modifiable factors that improve and maximize peak bone mass at an early age is necessary to design more effective intervention programs to prevent osteoporosis. To identify these modifiable factors, we analyzed the relationship of physical activity (PA), physical fitness, body composition, and dietary intake with bone stiffness index (SI), measured by quantitative ultrasonometry in young university students (18–21 years). Moderate-to-vigorous PA (MVPA) was the strongest predictor of SI (β = 0.184; p = 0.035). SI was most closely related with very vigorous PA in males (β = 0.288; p = 0.040) and with the number of steps/day in females (β = 0.319; p = 0.002). An association between thigh muscle and SI was consistent in both sexes (β = 0.328; p < 0.001). Additionally, extension maximal force was a bone SI predictor factor in females (β = 0.263; p = 0.016) independent of thigh muscle perimeter. Calcium intake was the only nutrition parameter that had a positive relationship with SI (R = 0.217; p = 0.022). However, it was not included as a predictor for SI in our regression models. This study identifies predictors of bone status in each sex and indicates that muscle and bone interrelate with PA and fitness in young adults.