Body composition and bone mass in post-menopausal women

Epidemiology of work-related fall injuries resulting in hospitalisation: individual and work risk factors and severity

OBJECTIVES

Injuries at work are common and costly for individuals and employers. A common mechanism of workplace injury is through falls, but there have been few epidemiological studies of risk factors. This study aimed to identify patient, work and injury factors associated with injuries causing hospitalisation after falling at work in Victoria, Australia.

METHODS

Data came from work-related hospitalised injury admissions, identified by International Classification of Diseases and Related Health Problems, Tenth Revision Australian Modification codes and compensation status, from Victorian Admitted Episodes Dataset between 1 July 2017 and 30 June 2022. Multivariate logistic regression analyses were conducted to identify factors associated with same-level falls and falls from height.

RESULTS

This study included 42 176 work-related injury admissions: 8669 (20.6%) fall injuries and 33 507 (79.4%) other injuries. Rates of high falls were more common in males than females (0.44 (95% CI: 0.43, 0.46) vs 0.08 (0.08, 0.09) admissions per 1000 employed), while same-level falls were more common in females than males (0.21 (0.20, 0.22) vs 0.18 (0.17, 0.18)). Patients with same-level fall injuries, relative to all other work injuries, were more likely to be older women, and have at least one chronic condition; falls from height were associated with male sex and construction work and more likely to result in intracranial, internal organ injuries and fractures and longer hospital stay than non-fall injuries.

CONCLUSION

Work-related falls were common and relatively severe. Same-level falls are relatively likely to occur in older women, the fastest-growing workplace demographic, and therefore the incidence is expected to increase. Comorbidities are an important fall risk factor. Employers could consider industry-relevant high and same-level fall prevention strategies for reducing the workplace injury burden.

Nationwide Trends in Osteoporosis in Koreans With Disabilities From 2008 to 2017

This study examined the 10-year trends in the prevalence of osteoporosis according to disability grade and type compared with those without disabilities in South Korea. We linked national disability registration data with the National Health Insurance claims data. Age- and sex-standardized prevalence of osteoporosis were analyzed from 2008 to 2017 according to sex, disability type, and disability grade. Adjusted odds ratios for osteoporosis according to disability characteristics in the most recent years' data were also confirmed by multivariate analysis. Over the past decade, the prevalence of osteoporosis has increased in people with disabilities compared with people without disabilities, and the gap has gradually widened from 7% to 15%. By analysis of the most recent year data, both male and female individuals with disabilities had a higher risk of osteoporosis than those without disability (odds ratios [OR] 1.72, 95% confidence interval [CI] 1.70-1.73 in males; OR 1.28, 95% CI 1.27-1.28 in females); the multivariate-adjusted OR was especially prominent in disability related to respiratory disease (OR 2.07, 95% CI 1.93-2.21 in males; OR 1.74; 95% CI 1.60-1.90 in females), epilepsy (OR 2.16, 95% CI 1.78-2.61 in males; OR 1.71; 95% CI 1.53-1.91 in females), and physical disability types (OR 2.09, 95% CI 2.06-2.21 in males; OR 1.70; 95% CI 1.69-1.71 in females). In conclusion, the prevalence and risk of osteoporosis have increased in people with disabilities in Korea. In particular, the risk of osteoporosis increases significantly in people with respiratory diseases, epilepsy, and physical disability types. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Evaluation of bone density and skeletal muscle mass after sleeve gastrectomy using computed tomography method

Introduction

Sleeve gastrectomy is the most common surgical procedure to reduce weight and treat metabolic complications in patients with moderate-to-severe obesity; however, it affects the musculoskeletal system. Dual-energy X-ray absorptiometry (DXA), which is commonly used to measure bone mineral density (BMD), may be affected by excess fat tissue around the bones, interrupting BMD measurement. Due to the strong correlation between DXA and the Hounsfield units (HU) obtained from computed tomography (CT) scans, BMD assessment using clinical abdominal CT scans has been useful. To date, there has been no report of detailed CT evaluation in patients with severe obesity after sleeve gastrectomy.

Objective

This study investigated the effect of sleeve gastrectomy in severely obese patients on bone and psoas muscle density, and cross-sectional area using retrospective clinical CT scans.

Methods

This was a retrospective observational study that included 86 patients (35 males and 51 females) who underwent sleeve gastrectomy between March 2012 and May 2019. Patients' clinical data (age at the time of surgery, sex, body weight, body mass index (BMI), comorbidities, and preoperative and postoperative blood test results, HU of the lumbar spine and psoas muscle and psoas muscle mass index (PMI)) were evaluated.

Results

The mean age at the time of surgery was 43 years, and the body weight and BMI significantly reduced (p < 0.01) after surgery. The mean hemoglobin A1c level showed significant improvement in males and females. Serum calcium and phosphorus levels remained unchanged before and after surgery. In CT analysis, HU of the lumbar spine and psoas muscle showed no significant decrease, but PMI showed a significant decrease (p < 0.01).

Conclusions

Sleeve gastrectomy could dramatically improve anthropometric measures without causing changes in serum calcium and phosphorus levels. Preoperative and postoperative abdominal CT revealed no significant difference in the bone and psoas muscle density, and the psoas muscle mass was significantly decreased after sleeve gastrectomy.

Sensitivity and Specificity of Anthropometric Indices in Identifying Obesity in Women over 40 Years of Age and Their Variability in Subsequent Decades of Life

Anthropometric measurements and indices are a simple and inexpensive method to assess normal physical development and quickly identify the risk of diseases. The aim of the study was to verify the sensitivity (Se) and specificity (Sp) of selected anthropometric indices in a group of women over 40 years. The study included 87 women (group I-40 to 49 years, group II-50 to 59 years, group III-60 to 69 years, and group IV-70 to 79 years). Anthropometric characteristics were measured: body mass (BM), body height (BH), waist circumference (WC), and hip circumference (HC). Body mass index (BMI), body adiposity index (BAI), waist-hip ratio (WHR), and waist-to-height ratio (WHTR) were calculated. The percentage of fat tissue (FT) and visceral fat volume (FV) were evaluated using DEXA. A decrease in mean BH with an increase in the mean WC, WHR, and WHTR in subsequent decades. There were strong statistically significant correlations between FT and most indicators (except for WHR). FV was correlated at a strong or moderate level with most parameters. In the group of women aged 40 to 80 years, the most favorable AUC was obtained for WC, followed by BMI. BAI can be recommended as a complementary indicator to BMI.

Gout as a risk factor for osteoporosis: A Korean population-based study

Uric acid acts as both an antioxidant and a pre-oxidant that induces oxidative stress; thus, it plays a paradoxical role in inflammation. However, the effect of gout, a hallmark of hyperuricemia, on osteoporosis remains unclear. Therefore, this study aimed to investigate the association between gout and osteoporosis. This retrospective cohort study used data from the Korean National Health Insurance Service Database. In total, 628,565 participants who were diagnosed with gout and prescribed medications for gout for at least 90 days were selected. The control cohort included patients with no history of gout or use of gout medication. Age and sex 1:1 propensity score matching and Cox proportional hazards models were used to investigate risk factors for osteoporosis. In total, 305,810 patients with gout met the inclusion criteria. Compared with the control group, both men and women with gout showed an increased incidence rate ratio of osteoporosis. In the stratified analysis by age, patients with gout showed an increased incidence rate ratio for osteoporosis in all age groups, except for those over 80 years of age (P < .001). Gout showed an increased hazard ratio of 1.48 (95% CI: 1.45-1.51, P < .001). The female sex has also been identified as a risk factor for osteoporosis. Patients in their 70s had the highest HR. Gout is significantly associated with the risk of osteoporosis. In particular, the results of this study showed that the incidence of osteoporosis increased up to four times in male patients in their 20s with gout compared to without gout.

Post-hospital falls incidence and risk factors among older adults: a systematic review and meta-analysis

BACKGROUND

Post-hospital falls constitute a significant health concern for older adults who have been recently discharged from the hospital.

OBJECTIVES

To systematically summarise existing evidence on the incidence and risk factors for post-hospital falls among older adults.

METHODS

A systematic review and meta-analysis was conducted. Six electronic databases were searched to identify cohort studies investigating the incidence and risk factors for post-hospital falls in older adults. The incidence and risk factors for post-hospital falls were extracted. The meta-analysis was used to calculate pooled incidences and 95% confidence intervals (CI). The meta-regression and subgroup meta-analysis were conducted to explore sources of heterogeneity in incidence proportions across the eligible studies. A qualitative synthesis was performed for the post-hospital falls risk factors.

RESULTS

Eighteen studies from eight countries (n = 9,080,568) were included. The pooled incidence proportion of any and recurrent post-hospital falls was 14% (95% CI: 13%-15%) and 10% (95% CI: 5%-14%), respectively. Follow-up period, study quality, study country, setting, percentage of female subjects, percentage of subjects with previous falls and the primary data collection method for falls significantly contributed to the 64.8% of the heterogeneity in incidence proportions. Twenty-six risk factors for post-hospital falls were identified in the eligible studies, where biological factors were the most commonly identified factors. The highest risks were reported for previous falls, previous fractures, delirium and neurological diseases.

CONCLUSION

The findings of this study suggested future post-hospital falls prevention should prioritise the needs of older adults with the dominant risk factors. Further investigations into the period-specific incidence and socioeconomic and environmental risk factors for post-hospital falls are also required.

Bone Mineral Density and Related Scores in Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Parkinson's disease (PD) is the second most common degenerative neurologic disorder in older adults, and increasing attention has been paid to bone health in PD. Although several studies have shown that patients with PD have a lower bone mineral density (BMD) than do non-PD controls, there have been no systematic reviews in recent years.

METHODS

PubMed, Medline, and Web of Science were used to search relevant studies up to May 2020. BMD, BMD T score, and BMD Z score of patients with and without PD were statistically analyzed. Meta-analysis was conducted using Review Manager version 5.3.

RESULTS

This meta-analysis included 17 studies comprising 10,289 individuals. In the meta-analysis, adults with PD had lower total body, total hip, total radius, lumbar spine, total femur, femur neck, right-hand, and left-hand BMD than did non-PD controls. The T score of total body BMD, total hip BMD, total radius BMD, lumbar spine BMD, L1-L4 spine BMD, total femur BMD, and femur neck BMD in adults with PD were lower than those in non-PD controls. Futhermore, the Z score of total body BMD, total hip BMD, total radius BMD, lumbar spine BMD, L1-L4 spine BMD, and femur neck BMD was lower in adults with PD than in non-PD controls.

CONCLUSIONS

Patients with PD had a lower BMD, BMD T score, and BMD Z score compared with non-PD controls. Therefore, clinicians should routinely monitor BMD of patients with PD to prevent falling and fragility fractures in older adults and optimize BMD before surgical treatment of severe spinal deformity caused by PD.

Fat and Lean Mass Predict Bone Mass During Energy Restriction in Sedentary and Exercising Rodents

Energy restriction (ER) causes bone loss, but the impact of exercise during ER is less understood. In this study, we examined the impact of metabolic hormones and body composition on both total body bone mineral content (BMC) and local (proximal tibia) volumetric bone mineral density (vBMD) during short- (4 weeks) and long-term (12 weeks) ER with and without exercise in adult female rats. Our first goal was to balance energy between sedentary and exercising groups to determine the impact of exercise during ER. Second, we aimed to determine the strongest predictors of bone outcomes during ER with energy-matched exercising groups.

Methods: Female Sprague–Dawley rats were divided into three sedentary groups (ad libitum, –20% ER, and –40% ER) and three exercising groups (ad libitum, –10% ER, and –30% ER). Approximately a 10% increase in energy expenditure was achieved via moderate treadmill running (∼60–100 min 4 days/week) in EX groups. n per group = 25–35. Data were analyzed as a 2 × 3 ANOVA with multiple linear regression to predict bone mass outcomes.

Results: At 4 weeks, fat and lean mass and serum insulin-like growth factor-I (IGF-I) predicted total body BMC (R² = 0.538). Fat mass decreased with ER at all levels, while lean mass was not altered. Serum IGF-I declined in the most severe ER groups (–40 and –30%). At 12 weeks, only fat and lean mass predicted total body BMC (R² = 0.718). Fat mass declined with ER level regardless of exercise status and lean mass increased due to exercise (+5.6–6.7% vs. energy-matched sedentary groups). At the same time point, BMC declined with ER, but increased with exercise (+7.0–12.5% vs. energy-matched sedentary groups). None of our models predicted vBMD at the proximal tibia at either time point.

Conclusion: Both fat and lean mass statistically predicted total body BMC during both short- and long-term ER. Fat and lean mass decreased with ER, while lean mass increased with EX at each energy level. Measures that predicted total body skeletal changes did not predict site-specific changes. These data highlight the importance of maintaining lean mass through exercise during periods of ER.

Fat-Bone Interactions in Adults With Spina Bifida

Context:

Spina bifida (SB) can lead to changes in body composition and bone mineral density (BMD) through diminished ambulation, renal impairment, and anticonvulsant medication. With increased life expectancy, diseases such as obesity and osteoporosis are emerging comorbidities in SB, with limited data to guide management.

Objective:

To examine the relationship between cardiometabolic factors, body composition, BMD, and minimal trauma fractures (MTFs) in adults with SB.

Design:

Retrospective cross-sectional study.

Setting and Participants:

Forty-nine adults with SB (median age, 32.7 years; interquartile range, 22.6 to 39.0) who had undergone dual-energy x-ray absorptiometry imaging at a single tertiary hospital from 2004 to 2015.

Results:

The mean body mass index was 31.7 ± 7.5 kg/m2; 26 (53.1%) were obese. Using age- and sex-matched fat percentiles from the National Health and Nutrition Examination Survey III, 62.5% had a total body percentage fat greater than the 95th percentile. Low bone mass (defined as a Z-score of ≤−2.0) was present in 21.9% at the L1 vertebra and in 35.1% at the femoral neck. Ten (20.4%) had a history of MTFs. A BMD or Z-score at L1, femoral neck, or total body site did not correlate with the occurrence of MTF. Fat mass was significantly and positively associated with BMD after adjustment for age, sex, and height and accounted for 18.6% of the variance in BMD (P = 0.005). The prevalence of metabolic comorbidities, such as hypertension (20.4%) and obstructive sleep apnea (16.3%), was high.

Conclusions:

Obesity and low BMD are common in young adults with SB. An increased fat mass correlated significantly with BMD. The prevalence of metabolic complications in patients with SB is increased and deserves further study.

Lean Mass and Body Fat Percentage Are Contradictory Predictors of Bone Mineral Density in Pre-Menopausal Pacific Island Women

Anecdotally, it is suggested that Pacific Island women have good bone mineral density (BMD) compared to other ethnicities; however, little evidence for this or for associated factors exists. This study aimed to explore associations between predictors of bone mineral density (BMD, g/cm²), in pre-menopausal Pacific Island women. Healthy pre-menopausal Pacific Island women (age 16–45 years) were recruited as part of the larger EXPLORE Study. Total body BMD and body composition were assessed using Dual X-ray Absorptiometry and air-displacement plethysmography (n = 83). A food frequency questionnaire (n = 56) and current bone-specific physical activity questionnaire (n = 59) were completed. Variables expected to be associated with BMD were applied to a hierarchical multiple regression analysis. Due to missing data, physical activity and dietary intake factors were considered only in simple correlations. Mean BMD was 1.1 ± 0.08 g/cm². Bone-free, fat-free lean mass (LMO, 52.4 ± 6.9 kg) and age were positively associated with BMD, and percent body fat (38.4 ± 7.6) was inversely associated with BMD, explaining 37.7% of total variance. Lean mass was the strongest predictor of BMD, while many established contributors to bone health (calcium, physical activity, protein, and vitamin C) were not associated with BMD in this population, partly due to difficulty retrieving dietary data. This highlights the importance of physical activity and protein intake during any weight loss interventions to in order to minimise the loss of muscle mass, whilst maximizing loss of adipose tissue.

Risk Factors of Bone Mass Loss at the Lumbar Spine: A Longitudinal Study in Healthy Korean Pre- and Perimenopausal Women Older than 40 Years

Longitudinal studies on bone mass decline for healthy women are sparse. We performed a retrospective longitudinal study to evaluate the factor associated with bone mass changes at the lumbar spine in healthy Korean pre- and perimenopausal women over the age of 40. We examined the relation of blood tests including thyroid function tests at baseline and follow-up to the annual percentage changes in average BMD of L2-L4 (A%ΔLSBMD). Four hundred and forty-three subjects without diseases or medications pertaining to bone metabolism were analyzed. The mean A%ΔLSBMD in these subjects was -0.45%/year. Though a significant correlation was observed between the A%ΔLSBMD and age, serum thyroid-stimulating hormone (TSH) level, total cholesterol (TC) level, low-density lipoprotein cholesterol (LDL-C) level, and estimated glomerular filtration rate (eGFR) at baseline and follow-up, there was a weak correlation between A%ΔLSBMD and these variables. From multiple linear regression analyses, the percent body fat, age, serum TSH level, serum uric acid level, and the menopause at follow-up were showed to have a significant association with the A%ΔLSBMD. Unlike age, percent body fat, and menopause at follow-up, which had a negative association with the A%ΔLSBMD, serum TSH level and serum uric acid level, had a positive association with the A%ΔLSBMD. The results from our study showed that the notable risk factors of BMD loss at the lumbar spine in population of our study were advancing age, menopause, higher percent body fat, lower normal TSH, and lower serum uric acid levels.

Imaging of the muscle-bone relationship

Muscle can be assessed by imaging techniques according to its size (as thickness, area, volume, or alternatively, as a mass) and architecture (fiber length and pennation angle), with values used as an anthropometric measure or a surrogate for force production. Similarly, the size of the bone (as area or volume) can be imaged using MRI or pQCT, although typically bone mineral mass is reported. Bone imaging measures of mineral density, size, and geometry can also be combined to calculate bone's structural strength-measures being highly predictive of bone's failure load ex vivo. Imaging of muscle-bone relationships can, hence, be accomplished through a number of approaches by adoption and comparison of these different muscle and bone parameters, dependent on the research question under investigation. These approaches have revealed evidence of direct, mechanical muscle-bone interactions independent of allometric associations. They have led to important information on bone mechanoadaptation and the influence of muscular action on bone, in addition to influences of age, gender, exercise, and disuse on muscle-bone relationships. Such analyses have also produced promising diagnostic tools for clinical use, such as identification of primary, disuse-induced, and secondary osteoporosis and estimation of bone safety factors. Standardization of muscle-bone imaging methods is required to permit more reliable comparisons between studies and differing imaging modes, and in particular to aid adoption of these methods into widespread clinical practice.

The effect of gonadal status on body composition and bone mineral density in transfusion-dependent thalassemia

Patients with transfusion-dependent thalassemia have abnormal growth, hormonal deficits, and increased bone loss. We investigated the relationship between skeletal muscle mass, fat mass, and bone mineral density in adult subjects with transfusion-dependent thalassemia based on their gonadal status. Our findings show that hypogonadism attenuates the strength of the muscle-bone relationship in males but strengthens the positive correlation of skeletal muscle mass and fat mass in female subjects.

INTRODUCTION

Transfusion-dependent thalassemia is associated with a high prevalence of fractures. Multiple hormonal complications, in particular hypogonadism, can lead to changes in body composition and bone mineral density (BMD). We investigated for the first time the relationship between skeletal muscle mass (SMM), fat mass, and BMD in adult subjects with transfusion-dependent thalassemia based on their gonadal status.

METHODS

A retrospective cohort study of 186 adults with transfusion-dependent thalassemia was analyzed. Body composition and BMD were measured using dual energy X-ray absorptiometry. The association between skeletal muscle, fat, and BMD was investigated through uni-, multi-, and stepwise regression analyses after adjusting for multicollinearity. SMM was derived using the formula, SMM = 1.19 × ALST-1.65, where ALST is equivalent to the sum of both arm and leg lean tissue mass.

RESULTS

There were 186 subjects, males (43.5 %) and females (56.5 %), with a median age of 36.5. Hypogonadism was reported in 44.4 % of males and 44.7 % of females. SMM and BMD were positively correlated and strongest in eugonadal males (0.36 ≤ R (2) ≤ 0.59), but the association was attenuated in hypogonadal males. SMM (0.27 ≤ R (2) ≤ 0.69) and total fat mass (0.26 ≤ R (2) ≤ 0.55) were positively correlated with BMD in hypogonadal females, but the correlation was less pronounced in eugonadal females. Leg lean tissue mass and arm lean tissue mass in males and females, respectively, were most highly correlated to BMD in the stepwise regression analysis.

CONCLUSION

Hypogonadism attenuates the strength of the muscle-bone relationship in males but strengthens the positive correlation of skeletal muscle mass and fat mass in female subjects. This study supports the notion that exercise is important for maintaining BMD and the need to optimize treatment of hypogonadism in patients with transfusion-dependent thalassemia.

Jump power and force have distinct associations with cortical bone parameters: findings from a population enriched by individuals with high bone mass

CONTEXT

Little is known of the relationships between muscle function and bone, based on the recently developed technique of jumping mechanography.

OBJECTIVE

Our objective was to determine associations between peak ground reaction force and peak power during a 1-legged hopping test and a single 2-legged jump, respectively, and cortical bone parameters.

DESIGN AND SETTING

This was a cross-sectional observational study in participants from the high bone mass cohort.

PARTICIPANTS

Participants included 70 males (mean age 58 years) and 119 females (mean age 56 years); high bone mass cases and controls were pooled.

MAIN OUTCOME MEASURES

Total hip bone mineral density (BMD) (measured by dual-energy x-ray absorptiometry scanning) and mid-tibial peripheral quantitative computed tomography (Stratec XCT2000L).

RESULTS

Jump power was positively related to hip BMD (standardized β [95% confidence interval]=0.29 [0.07, 0.51], P=.01), but hopping force was not (0.03 [-0.16, 0.22], P=.74) (linear regression analysis adjusted for age, gender, height, and weight). In 113 participants with force and peripheral quantitative computed tomography data, both jump power and hopping force were positively associated with tibial strength strain index (0.26 [0.09, 0.44], P<.01; and 0.24 [0.07, 0.42], P=.01 respectively). Although hopping force was positively associated with bone size (total bone area 0.22 [0.03, 0.42], P=.02), jump power was not (0.10 [-0.10, 0.30], P=.33). In contrast, jump power was inversely associated with endocortical circumference adjusted for periosteal circumference (-0.24 [-0.40, -0.08], P<.01) whereas no association was seen for hopping force (-0.10 [-0.26, 0.07], P=.24).

CONCLUSIONS

Although power and force are both positively associated with cortical bone strength, distinct mechanisms appear to be involved because power was primarily associated with reduced endocortical expansion (reflected by endocortical circumference adjusted for periosteal circumference, and hip BMD), whereas force was associated with increased periosteal expansion (reflected by total bone area).

Response of parathyroid hormone to exercise and bone mineral density in adolescent female athletes

BACKGROUND

This study investigates 1) the effects of amount of exercise on levels of serum parathyroid hormone (PTH) and calcium, and 2) the relationship between PTH response and bone mineral density in adolescent female athletes.

SUBJECTS

Twenty-one female athletes on a top-ranked high school basketball team in Japan participated in a one-month intensive basketball program. Subjects were divided into moderate-exercise and strenuous-exercise groups.

METHODS

The amount of exercise was quantified using estimated metabolic equivalent (METs) and exercise hours. Levels of serum intact-PTH and calcium were examined five times: twice before training to establish a baseline (T(-1) and T(0)), once 3rd week of the training period (T(1), once immediately at the end of the program (T(2)), and again one week later(3)). Bone mineral density of forearm (distal-BMD) was measured one week after the end of the program. PTH levels at T(1), T(2) and(3) were regressed on PTH at baseline (T(0)) for both groups and examined for statistical significance. Multiple regression analyses of the changes of PTH and distal-BMD were conducted.

RESULTS

1) Strenuous-exercise subjects showed both increased and decreased PTH levels, while moderate-exercise subjects showed a uniform decrease in PTH throughout the exercise period. 2) Increased PTH was an independent negative predictor of distal-BMD, while high lean body mass, increased serum Ca, and exercise volume were positive predictors.

CONCLUSION

The amount of exercise affects PTH response: moderate exercise suppresses PTH secretion, while strenuous exercise is apt to induce continuous secretion, which has a negative effect on BMD.

Green tea polyphenols benefits body composition and improves bone quality in long-term high-fat diet-induced obese rats

This study investigates the effects of green tea polyphenols (GTPs) on body composition and bone properties along with mechanisms in obese female rats. Thirty-six 3-month-old Sprague Dawley female rats were fed either a low-fat (LF) or a high-fat (HF) diet for 4 months. Animals in the LF diet group continued on an LF diet for additional 4 months, whereas those in the HF diet group were divided into 2 groups: with GTP (0.5%) or without in drinking water, in addition to an HF diet for another 4 months. Body composition, femur bone mass and strength, serum endocrine and proinflammatory cytokines, and liver glutathione peroxidase (GPX) protein expression were determined. We hypothesized that supplementation of GTP in drinking water would benefit body composition, enhance bone quality, and suppress obesity-related endocrines in HF diet-induced obese female rats and that such changes are related to an elevation of antioxidant capacity and a reduction of proinflammatory cytokine production. After 8 months, compared with the LF diet, the HF diet increased percentage of fat mass and serum insulin-like growth factor I and leptin levels; reduced percentage of fat-free mass, bone strength, and GPX protein expression; but had no effect on bone mineral density and serum adiponectin levels in the rats. Green tea polyphenol supplementation increased percentage of fat-free mass, bone mineral density and strength, and GPX protein expression and decreased percentage of fat mass, serum insulin-like growth factor I, leptin, adiponectin, and proinflammatory cytokines in the obese rats. This study shows that GTP supplementation benefited body composition and bone properties in obese rats possibly through enhancing antioxidant capacity and suppressing inflammation.

Follicle-stimulating hormone is independently associated with lean mass but not BMD in younger postmenopausal women

PURPOSE

Increased follicle-stimulating hormone (FSH) has been associated with lower bone mineral density (BMD) in animal models and longitudinal studies of women, but a direct effect has not been demonstrated.

METHODS

We tested associations between FSH, non-bone body composition measures and BMD in 94 younger (aged 50 to 64 years) postmenopausal women without current use of hormone therapy, adjusting for sex hormone concentrations and clinical risk factors for osteoporosis. Lean mass, fat mass and areal BMD (aBMD) at the spine, femoral neck and total hip were measured using dual energy X-ray absorptiometry (DXA). Volumetric BMD (vBMD) was measured at the distal radius using peripheral quantitative computed tomography (pQCT).

RESULTS

FSH was inversely correlated with lean and fat mass, bioavailable estradiol, spine and hip aBMD, and vBMD at the ultradistal radius. In the multivariable analysis, FSH was independently associated with lean mass (β=-0.099, p=0.005) after adjustment for age, race, years since menopause, bioavailable estradiol, bioavailable testosterone, LH, PTH, SHBG and urine N-telopeptide. FSH showed no statistically significant association with aBMD at any site or pQCT measures at the distal radius in adjusted models. Race was independently associated with aBMD, and race and urine N-telopeptide were independently associated with bone area and vBMD.

CONCLUSIONS

After adjustment for hormonal measures and osteoporosis risk factors, higher concentrations of FSH were independently associated with lower lean mass, but not with BMD. Previously reported correlations between FSH and BMD might have been due to indirect associations via lean mass or weight.

Relative importance of lean mass and fat mass on bone mineral density in a group of Lebanese postmenopausal women

The aim of this study was to determine the relative importance of lean mass and fat mass on bone mineral density (BMD) in a group of Lebanese postmenopausal women. One hundred ten Lebanese postmenopausal women (aged 65-84 yr) participated in this study. Age and years since menopause were recorded. Body weight and height were measured and body mass index (BMI) was calculated. Body composition (lean mass, fat mass, and fat mass percentage) was assessed by dual-energy X-ray absorptiometry (DXA). Bone mineral content (BMC) of the whole body (WB) and BMD of the WB, the lumbar spine (L1-L4), the total hip (TH), the femoral neck (FN), the ultra distal (UD) Radius, and the 1/3 Radius were measured by DXA. The expressions WB BMC/height and WB BMD/height were also used. Weight, BMI, fat mass, and lean mass were positively correlated to WB BMC, WB BMC/height, WB BMD/height, and to WB, L1-L4, TH, FN, UD Radius, and 1/3 Radius BMD. However, using multiple linear regression analyses, fat mass was more strongly correlated to BMC and to BMD values than lean mass after controlling for years since menopause. This study suggests that fat mass is a stronger determinant of BMC and BMD than lean mass in Lebanese postmenopausal women.

Ensembled artificial neural networks to predict the fitness score for body composition analysis

OBJECTIVES

To predict the nutrition and health status of staff and students in Yuan Ze University and select the influential variables from the total body composition variables, which should have similar predictive ability with the whole factors.

DESIGN

Spontaneous and voluntary physical examination.

SETTING

Sanitary and Health Care Section of Yuan Ze University in Taiwan.

PARTICIPANTS

1227 staff and students.

MEASUREMENTS

With the help of Inbody720TM, 139 body composition variables were measured and 60 variables were retained after data pre-processing. An ensembled artificial neural networks (EANN) prediction model was established and seven different methods for assessing variables importance were applied. Besides, classical linear and logistic regression models were developed for comparison with EANN prediction results.

RESULTS

The prediction performance of EANN model was satisfactory (RMSE (train) = 0.2686, RMSE (validation) = 0.2648, RMSE (test) = 0.3492). Since both the actual and simulation fitness score were at the range of 0 to 100, according to rounding off rule, the simulated value was almost the same with actual value. Besides, 12 important variables were obtained by seven methods for quantifying variable importance in EANN, which had similar predictive capability with 60 variables (RMSE (train) = 0.3263, RMSE (validation) = 0.322, RMSE (test) = 0.3226). The linear and logistic regression models results were both evidently worse than EANN results.

CONCLUSION

The results confirm that EANN is appropriate to approximate such a complicated, non-invasive and highly non-linear problem as body composition analysis. It can be helpful for nutritionists to manage and improve the nutrition and health condition of staff and students, by adjusting the 12 most important variables.

Relation of body fat distribution to femoral neck bone density and endometrial thickness in postmenopausal women

OBJECTIVE

Menopause is associated with accelerated bone loss, a decrease in lean mass, an increase and redistribution of fat mass in the trunk region. Trunk obesity has been considered as a risk factor for endometrial cancer. We aimed to determine if body composition and fat distribution are determinants of femoral neck bone mineral density (BMD) and endometrial thickness in healthy postmenopausal women.

STUDY DESIGN

Subjects were 40 healthy postmenopausal women with biopsy proven atrophic endometrium. Anthropometrical variables (total fat mass, trunk and leg fat masses, lean body mass and femoral neck BMD) were measured by dual energy X-ray absorptiometry.

RESULTS

Femoral neck BMD was positively correlated with body mass index, total fat mass, trunk fat mass, leg fat mass and endometrial thickness, and negatively correlated with age, years since menopause and FSH levels. Trunk fat and age remained significant determinants of femoral neck BMD (R(2) = 32.9 %, p < 0.001) and endometrial thickness was significantly associated with femoral neck BMD and oestradiol levels (R(2) = 46.5%, p < 0.0001) on regression analysis.

CONCLUSION

Truncal adiposity rather than overall adiposity or lean mass are more closely associated with femoral neck BMD and there is no relationship between subcutaneous fat mass and endometrial thickness in postmenopausal women.

Estrogen therapy and bone mineral density in African-American and Caucasian women

Controlling for body size and composition, the authors examined the association between estrogen therapy and bone mineral density in older African-American and Caucasian women. In 1992-1998, 443 African-American and 989 Caucasian women aged 45-87 years were assessed for medication use, laboratory variables, behavioral characteristics, and bone mineral density. The mean age was 61.3 (95% confidence interval: 60.3, 62.3) years in African Americans and 71.0 (95% confidence interval: 70.4, 71.7) years in Caucasians (P < 0.001). All measures of body size and composition were significantly greater in the African-American women compared with Caucasian women (P < 0.001). As expected, African Americans had significantly higher bone mineral density at all 4 sites independent of age, weight, body composition, estrogen use, and lifestyle factors. Although Caucasians were significantly more likely to currently use estrogen (48.9% vs. 33.9%; P < 0.001), African Americans not using estrogen had significantly higher bone mineral density at all sites except the spine than Caucasians who were using estrogen. Regression models including age and lean mass explained the most variation in bone mineral density (R(2) range = 0.13-0.37). Results suggest that higher levels of bone mineral density in African-American women were not due to estrogen use.

Regional body composition: cross-calibration of DXA scanners--QDR4500W and Discovery Wi

Differences exist in body composition assessed by dual-energy X-ray absorptiometers (DXAs) between devices produced by different manufacturers and different models from the same manufacturer. Cross-calibration is needed to allow body composition results to be compared in multicenter trials or when scanners are replaced. The aim was to determine reproducibility and extent of agreement between two fan-beam DXA scanners (QDR4500W, Discovery Wi) for body composition of regional sites. The sample was: 39 women 50.6 +/- 9.6 years old with BMI 26.8 +/- 5.5 kg/m(2), body fat 33 +/- 7%. Four whole body scans (two on each device) were performed over 3 weeks. Major variables were fat mass, nonosseous lean mass, and bone mineral content (BMC) for the truncal and appendicular regions. Extent of agreement was assessed using Bland and Altman plots. Both devices demonstrated good precision with mean test-retest differences close to zero for fat mass, nonosseous lean mass, and BMC of the truncal and appendicular regions. Evaluation of interdevice agreement revealed significant differences for truncal and appendicular BMC, nonosseous lean mass, and fat mass. The greatest interdevice difference was for truncal fat mass (0.69 +/- 0.60 kg). Differences in truncal and appendicular fat mass increased in magnitude at higher mean values. Furthermore, differences in truncal and appendicular fat mass were strongly related to BMI (R = -0.61, R = -0.55, respectively). In conclusion, in vivo cross-calibration is important to ensure comparability of regional body composition data between scanners, especially for truncal fat mass and for subjects with higher BMI.

Association between bone, body composition and strength in premenarcheal girls and postmenopausal women

AIM

The study examined whether associations between bone, body composition and strength are age dependent.

SUBJECTS AND METHODS

Two age levels (premenarcheal girls and postmenopausal women on HRT) were studied in a 10-month follow-up. Bone, lean and fat mass were measured by dual-energy X-ray absorptiometry (DXA), and strength was measured using an isokinetic dynamometer.

RESULTS

In girls, significant correlations were found between mass (lean, fat and body mass), strength and most bone characteristics (r = 0.15-0.93). At the proximal femur changes in bone mineral density (BMD) were moderately related to changes in body composition. In the women, body mass and lean mass were significantly correlated with most bone characteristics (r = 0.34-0.82). Low to moderate correlations were observed between changes in bone and changes in body composition. After controlling for lean mass the relation between strength and bone was no longer significant.

CONCLUSIONS

In premenarcheal girls, bone is partly determined by mass, with lean mass the most important predictor at the femoral sites. In postmenopausal women, lean mass is an important determinant of bone mineral content (BMC) and BMD, but changes in BMD are related to changes in fat. The relation between strength and BMD is mainly attributable to the relation between lean mass and BMD. The contributory effects of soft tissue to bone change over different life periods.

Changes in soft tissue composition are the primary predictors of 4-year bone mineral density changes in postmenopausal women

Changes in body weight influence bone mineral density, but the role of body composition is not clear in postmenopausal women. Body weight and soft tissue composition predicted bone changes independent of calcium supplementation and exercise frequency, indicating that soft tissue composition should be measured in clinical trials.

INTRODUCTION

The purpose of this study was to examine the relationship between changes in body weight and composition and changes in 4-year bone mineral density (BMD) after accounting for age, 4-year exercise frequency (EX), and 4-year calcium supplement intake (CA) in postmenopausal women with and without hormone therapy (HT).

METHODS

Postmenopausal women (aged 40-65 years) either using HT (for 1-3.9 years) or not using HT (for > or =1 year) were recruited to the study. EX and CA was monitored throughout the study and 167 women completed 4 years. BMD and soft tissue composition measurements were made using dual-energy X-ray absorptiometry. Regression was used to predict 4-year BMD changes from EX, CA, age, baseline and 4-year changes in body weight and composition. HT users (n = 115, 55.3 +/- 4.3 years) and non-users (n = 52, 57.5 +/- 4.7 years) were analyzed separately.

RESULTS

The models predicting regional BMD changes that included soft tissue composition changes explained the most variation compared with those with body weight or EX and CA alone. Larger amounts of variation in BMD changes were explained in the no HT group.

CONCLUSION

Body composition changes are important positive predictors of BMD changes independent of EX and CA supplementation, but their contribution varies according to bone site and with HT use.

Body composition and muscle strength as predictors of bone mineral density in Crohn's disease

Compromised skeletal status is a frequent finding in patients with Crohn's disease (CD), leading to increased fracture risk. Low body weight is associated with bone mineral density (BMD) in CD, although the relative importance of its components, lean and fat mass, is unclear. Muscle strength is also a predictor of BMD in nondiseased populations; however, its association with bone in CD is unknown. We examined the independent effects of body composition and muscle strength on regional and whole-body BMD in a cohort of CD patients. Sixty men and women, aged 22-72 years, with disease duration of 13 +/- 7 years, underwent scanning of the spine, hip, forearm, and whole-body BMD by dual-energy X-ray absorptiometry (DXA). Lean tissue, appendicular muscle mass (AMM), and fat mass were derived by DXA and grip strength by dynamometry. Medical history, medication usage, clinical variables, and nutritional intake were obtained by questionnaire. Prevalence of osteopenia and osteoporosis was 32 and 17%, respectively, with osteopenia more common at the hip and osteoporosis more common at the spine. In multiple regression analyses, AMM was an independent predictor of whole-body and regional BMD whereas lean mass was an independent predictor at the hip. Neither grip strength nor fat mass was independently associated with BMD. Of the components of body composition, muscle mass was strongly associated with regional and whole-body BMD. Preserving or augmenting muscle mass in this population may be a useful strategy to preserve BMD and thereby reduce fracture risk.

Bioimpedance: can its addition to simple clinical criteria enhance the diagnosis of osteoporosis?

There is a great need for a simple means to identify individuals at risk of osteoporosis. Because bioimpedance (BI) estimates body composition, which is highly related to bone mineral density (BMD), we aimed to define the usefulness of BI to assess BMD. The relationships between BI and BMD were quantified using partial correlations. Multiple linear regression with a forward selection method was used to examine the predictive abilities of various body measurements on BMD at lumbar spine, femoral neck, and total hip. The abilities of BI to discriminate low BMD or to discriminate osteoporosis were evaluated using receiver operating characteristic (ROC) curve analysis. The relationships between BI and BMD at the spine and hip were evaluated in 345 Southern Chinese postmenopausal women and 390 men. After adjusting for age and weight, BI was inversely associated with BMD in both sexes (r = -0.053 to -0.195). Multiple linear regression analysis revealed that BI is a significant independent predictor of BMD in men. This finding was not confirmed in women. The area under the ROC curves (AUC) for BI as a single predictor to diagnose osteoporosis was 0.658 and 0.655 in women and men, respectively. The AUC was improved slightly with the addition of BI in the model that consisted of age and weight alone. Although BI was significantly associated with BMD, addition of BI did not enhance the ability to diagnose osteoporosis significantly compared with simple clinical criteria such as age and weight.

Adiponectin is a negative regulator of bone mineral and bone strength in growing mice

Obesity is associated with increased bone mineral density (BMD) but the mechanism for this is unclear. Serum levels of the adipokine adiponectin are inversely correlated with obesity, but results from studies on its relationship to bone mass are conflicting. The objective of this study was to compare bone mineral content (BMC), BMD and biomechanical strength properties of femur and lumbar vertebrae in 8- and 16-week old adiponectin transgenic mice (AdTg). These mice exhibit significantly elevated circulating adiponectin but have similar body weights compared to wild-type (WT) littermates that were used as controls. Female AdTg mice displayed significantly lower femur BMC at 8 and 16 weeks of age and femur neck peak load was significantly lower in 8-week old AdTg mice of both genders compared to controls. The peak load from compression testing of an individual lumbar vertebra was significantly lower in female AdTg mice compared to WT at 8 weeks, and this difference persisted at 16 weeks of age. In addition, lumbar vertebrae BMC was significantly lower in 16-week old male AdTg mice compared to WT although vertebra peak load was not different. Serum adiponectin levels were inversely correlated with femur BMC. In summary, elevated circulating adiponectin inhibits the acquisition of bone mass in growing mice and results in decreased biomechanical measures of functional strength that are surrogate measures of susceptibility to fractures. These results support a role for circulating adiponectin as a metabolic link that can explain, at least in part, the positive relationship between obesity and both bone mass and reduced susceptibility to fractures.

Bone mass in elderly patients with Parkinson's disease

OBJECTIVE

The objective of the present study was to find risk factors for low bone mineral density (BMD) in patients with Parkinson's disease (PD).

MATERIAL AND METHODS

Twenty-six PD patients and 26 age-and sex-matched healthy controls were assessed twice within a 1-year period. PD symptoms, body weight, body fat mass, BMD, physical activity, smoking and serum concentrations of several laboratory analyses were investigated.

RESULTS

BMD in different locations was lower in PD patients compared with their controls and decreased during the investigated year. BMD was lower in PD patients with low body weight. BMD Z-score of trochanter in the PD group was directly correlated to the degree of physical activity and indirectly to the length of recumbent rest. Total body BMD Z-score in the PD group was directly correlated to the degree of rigidity. Serum 25-hydroxy-vitamin D was slightly lower in PD patients.

CONCLUSION

Low body weight and low physical activity were risk factors for low BMD in PD, while rigidity seemed to be protective.

Bone mass in young women is dependent on lean body mass

Relationships between bone mineral density (BMD) and body mass, height, fat mass, and lean mass have been reported. This study examined the relationship between body size and composition on bone density in young premenopausal women. In this study, a cross-sectional design was used. Seventy-one healthy women aged between 24 and 36 yr selected to have a wide range of boy habitus (mean body mass index, 22.7+/-3.0) underwent a dual-energy X-ray absorptiometry (DXA) whole-body bone density scan (Hologic QDR 2000). Their bone density and soft tissue body composition and anthropometric parameters (skinfolds, girths, limb lengths, bone breadths, height, and body mass) were analyzed, and their body composition was assessed by underwater weighing (UWW). Bone-free lean mass (BFLM) determined by DXA was correlated with both bone mineral content (BMC) and BMD (r=0.74, p<0.001; r=0.48, p<0.001, respectively). In addition, fat-free mass (FFM) determined by UWW was correlated with BMC and BMD (r=0.80, p<0.001; r=0.48, p<0.001, respectively). Controlling for height in the model removed most of the correlations with whole-body BMD, with the exception of FFM, BFLM, and shoulder breadth (r=0.39, p<0.001; r=0.37, p<0.01; and r=0.34, p<0.01, respectively). No correlation was found between fat mass by DXA, UWW, and sum of skinfolds and BMD. These results indicate that bone mass in premenopausal women is dependent on lean body mass.

Body size and 24-hour urine composition

BACKGROUND

Greater body mass index (BMI) is a risk factor for kidney stones. However, the relation between BMI and the urinary excretion of many lithogenic factors remains unclear.

METHODS

We studied urine pH, urine volume, and 24-hour urinary excretion of calcium, oxalate, citrate, uric acid, sodium, magnesium, potassium, phosphate, and creatinine in stone-forming and non-stone-forming participants in the Health Professionals Follow-Up Study (599 stone-forming and 404 non-stone-forming men), Nurses' Health Study (888 stone-forming and 398 non-stone-forming older women), and Nurses' Health Study II (689 stone-forming and 295 non-stone-forming younger women). Each cohort was divided into quintiles of BMI. Tests of linear trend were conducted by 1-way analysis of variance. Linear regression models were adjusted for age, history of stone disease, dietary intake, and urinary factors.

RESULTS

Participants with greater BMIs excreted more urinary oxalate (P for trend <or= 0.04), uric acid (P < 0.001), sodium (P < 0.001), and phosphate (P < 0.001) than participants with lower BMIs. There was an inverse relation between BMI and urine pH (P <or= 0.02). Positive associations between BMI and urinary calcium excretion in men and stone-forming younger women (P <or= 0.02) did not persist after adjustment for urinary sodium and phosphate excretion. Because of differences in urinary volume and excretion of inhibitors such as citrate, we observed no relation between BMI and urinary supersaturation of calcium oxalate. Urinary supersaturation of uric acid increased with BMI (P <or= 0.01).

CONCLUSION

Positive associations between BMI and urinary calcium excretion likely are due to differences in animal protein and sodium intake. The greater incidence of kidney stones in the obese may be due to an increase in uric acid nephrolithiasis.

Relative contribution of body composition to bone mineral density at different sites in men and women of South Korea

We examined the relative contribution of body composition to bone mineral density (BMD) at various sites in 1406 Korean rural men and women, aged 19-80 years, from July to August 2004. The BMD was measured at peripheral (distal forearm and calcaneus) and central (lumbar spine at L1-L4, femoral neck, trochanter, and Ward's triangle) using dual-energy X-ray absorptiometry. In multivariate analyses, the linear regression models were adjusted for relevant covariates. In premenopausal women, only lean mass had a significant positive correlation with BMD at all sites. In postmenopausal women, fat mass was significantly positively correlated with BMD at all sites, except the Ward's triangle; fat mass was the only determinant of BMD at the lumbar, distal forearm, and calcaneus sites, whereas both lean and fat mass contributed to BMD at the hip, with the effect of lean mass being slightly greater than that of fat mass. In younger men, lean mass had a significant positive contribution to BMD at all sites, whereas fat mass appeared to contribute negatively to BMD at all sites, except the calcaneus. In older men, lean mass made a significant positive contribution to the BMD at all sites; fat mass also made a significant positive contribution to the BMD at the forearm and calcaneus. These data indicate that in the Korean rural population, lean mass may be an important determinant of the BMD, whereas fat mass may contribute positively to BMD only in postmenopausal women and older men.

Relationship between body composition and bone mineral density in women with and without osteoporosis: relative contribution of lean and fat mass

To assess the relationship of total fat mass (TFM) and total lean mass (TLM) with bone mineral density (BMD) and bone mineral content (BMC), we studied 770 postmenopausal white women after total body measurements by dual-energy X-ray absorptiometry. Height-independent bone mineral density (HIBMD) was also tested. The effects of TFM and TLM on the dependent variables HIBMD, BMD, and BMC were assessed by the univariate general linear model (UGLM). Age, age at menopause, height, and bone area were entered in the models as controlling variables when appropriate. In the total population, TLM and TFM were associated with BMD, BMC, and HIBMD (P < 0.001). Taking the T-score cut-off as -2.5, women without (463) and with (307) osteoporosis were then tested separately. In nonosteoporotic women, TLM was significantly associated with BMD, BMC, and HIBMD (P < 0.001), while TFM was not. In osteoporotic women, both TLM and TFM were associated with BMD to the same extent (P < 0.05), but not with HIBMD. Women without osteoporosis were then tested according to whether their TFM/TLM fraction was less than or greater than 1. In those with TFM/TLM less than 1, both TLM (P < 0.001) and TFM (P < 0.01), tested separately, were associated with BMD and BMC, but not with HIBMD. When TLM and TFM were tested at the same time and assessed by the same UGLM, only TLM (P < 0.001) still affected these three bone parameters. In women with TFM/TLM greater than 1, testing the body components both separately and at the same time and using the UGLM showed that TFM affected both BMC and BMD (P < 0.05), while TLM did not. In conclusion, our data indicate that both TFM and TLM affect bone density, with different physiological/pathological conditions modulating this relationship.

Racial differences in the association of subcutaneous and visceral fat on bone mineral content in prepubertal children

Total fat mass plays a significant role in determining bone mass, but the specific role of central adiposity independent of total fat mass has not been widely studied. Prepubertal (Tanner 1) children (n = 181; 65 boys, 116 girls, 7.8 +/- 1.5 years), including 99 Caucasians and 82 African Americans from Birmingham, Alabama, participated in this study. Body composition, including total body and trunk fat mass, and bone mineral content (BMC) were measured using dual-energy X-ray absorptiometry. Subcutaneous abdominal adipose tissue (SAAT) and intra-abdominal adipose tissue (IAAT) were determined by single-slice computed tomography (CT). After adjusting for gender, age, height, total fat, and lean mass, trunk weight was inversely correlated with BMC in Caucasians (r = -0.56, P < 0.0001) and in African Americans (r = -0.37, P < 0.05). In Caucasians, independent of gender, age, height, total fat, and lean mass, there was an inverse correlation between SAAT and BMC (r = -0.58, P < 0.0001) but no significant correlation between IAAT and BMC; in addition, SAAT explained 6% of the variance in BMC. In contrast, in African Americans, SAAT and BMC were not significantly correlated. However, while adjusting for gender, age, height, SAAT, total fat, and lean mass, an inverse association between IAAT and BMC was observed in African Americans (r = -0.50, P < 0.01); IAAT also explained 3% of the variance in BMC. These findings suggest that, in general, total abdominal weight is negatively associated with bone mass, but there appear to be racial differences with regard to the contributions of subcutaneous and visceral fat to BMC in prepubertal children.

Change in lean body mass is a major determinant of change in areal bone mineral density of the proximal femur: a 12-year observational study

Our objective was to assess the contribution of lean body mass (LBM) and fat body mass (FBM) to areal bone mineral density (aBMD) in women during the years surrounding menopause. We used a 12-year observational design. Participants included 75 Caucasian women who were premenopausal, 53 of whom were available for follow-up. There were two measurement periods: baseline and 12-year follow-up. At both measurement periods, bone mineral content and aBMD of the proximal femur, posterior-anterior lumbar spine, and total body was assessed using dual-energy X-ray absorptiometry (DXA). LBM and FBM were derived from the total-body scans. General health, including current menopausal status, hormone replace therapy use, medication use, and physical activity, was assessed by questionnaires. At the end of the study, 44% of the women were postmenopausal. After controlling for baseline aBMD, current menopausal status, and current hormone replacement therapy, we found that change in LBM was independently associated with change in aBMD of the proximal femur (P = 0.001). The cross-sectional analyses also indicated that LBM was a significant determinant of aBMD of all three DXA-scanned sites at both baseline and follow-up. These novel longitudinal data highlight the important contribution of LBM to the maintenance of proximal femur bone mass at a key time in women's life span, the years surrounding menopause.

Effects of tibolone on body composition in postmenopausal women: a 1-year follow up study

OBJECTIVE

We investigated the effects of 1-year tibolone treatment on body weight, body composition and indices of android obesity in postmenopausal women.

METHODS

Forty-four postmenopausal women participated in this open-label controlled study; mean age was 51.8+/-2.21 years and all women were menopausal for 3.8+/-1.40 years. Twenty-two of them started taking 2.5 mg tibolone (TIB) daily for 1 year, whereas the remaining 22 served as age-matched controls. All subjects underwent a structured interview, physical examination, body composition measurements performed by dual-energy X-ray absorptiometry (DXA) - Hologic QDR 4500 A, as well as bioelectrical body impedance analysis (BI) - Tanita TBF-215, Japan.

RESULTS

The TIB group did not significantly increase their weight (+0.4 kg), while the non-treated controls increased their mean weight by 1.4 kg (p=0.046). In the TIB group, DXA showed a non-significant body fat decrease by a mean of 0.5 kg and a non-significant lean mass increase by 0.8 kg, while in the control group, fat mass increased by 1.7 kg (p=0.032) and lean mass did not change. BI revealed that the TIB group had lost some fat ( approximately 0.6 kg, n.s.) and put some free-fat mass ( approximately 1.0 kg, p=0.048) without changes in total body water. The control group put on some fat ( approximately 1.1 kg, p=0.042) and lost some body water ( approximately 0.4 kg, n.s.).

CONCLUSION

Results from both methods of measuring body composition show a similar trend: a decrease in fat mass and an increase in lean mass in TIB treated subjects. From the body composition perspective, tibolone may be regarded as a preferential alternative to conventional hormonal therapy (HT) in postmenopausal women.

Difference in the relative contribution of lean and fat mass components to bone mineral density with generation

AIM

To investigate whether the relative contribution of body composition (lean and fat mass component) to bone mineral density (BMD) differs depending on generation or menopause.

METHODS

Subjects were 302 premenopausal women aged 30-49 years old and 197 postmenopausal women aged 50-69 years old. They were classified into four subgroups with 10-year increments. Age, height, weight and years since menopause (YSM) were recorded. Lumbar spine (L2-4), total body BMD, body fat mass, lean body mass (LBM), and the percentage of body fat (%fat) were measured using dual-energy X-ray absorptiometry. The correlation of body composition with BMD was investigated.

RESULTS

The mean age at menopause was 50.2 +/- 4.1 years old. On Pearson's correlation test, LBM was positively correlated with BMD of the two sites in all groups. In a group aged 60-69 years, both the %fat and body fat mass were correlated with BMD. On multiple regression analysis, LBM was the principal BMD determinant in women aged less than 60 years, while body fat mass and percentage fat were the principal BMD determinants in women aged 60-69 years. Mean %fat in the group aged 60-69 years was 35.5 +/- 7.3%, which was significantly higher than that in the group aged 50-59 years (33.0 +/- 6.7%, P < 0.05).

CONCLUSION

Although LBM still influences BMD up to 10 years after menopause, the body fat mass initially influences BMD after 60 years of age. These difference may be attributable to certain aging-related factor(s).

Bone mineral density of the proximal femur is not related to dynamic joint loading during locomotion in young women

We characterized the extent to which body mass influences the relationship between hip joint moments during locomotion and bone mineral density (BMD) of the proximal femur in healthy young women (n = 24). There is some evidence of a direct relationship between hip joint moments during locomotion and BMD of the proximal femur in patients with osteoarthritis. Nevertheless, based on expected simultaneous influences of body mass on BMD and joint moments during locomotion, we hypothesized that BMD would not be significantly associated with hip joint moments during locomotion independently of body mass. BMD of the nondominant proximal femur was determined using DXA. The hip joint moments were determined by gait analysis. The correlation between peak internal rotation moment and BMD of the intertrochanteric region was significant (r = 0.48; P = 0.019). However, body mass was significantly correlated to both BMD and the internal rotation moment (r = 0.59 and 0.70; P = 0.002 and <0.001, respectively). After accounting for the relationship between body mass and hip joint moment, the internal rotation moment was not significantly correlated to BMD of the proximal femur (r = 0.04, P = 0.34) indicating that BMD is not significantly associated with hip joint moments during locomotion independent of body mass in young healthy women.

Body composition: gender-specific risk factor of reduced quantitative ultrasound measures in older people

INTRODUCTION

Body composition has been reported as a significant determinant of bone mineral density. However, data regarding the relationship between the body composition and quantitative ultrasound (QUS) are scarce.

METHODS

This cross-sectional study examined risk factors of reduced QUS measures in older men and women. A total of 699 subjects aged 60 years old and over-458 women and 241 men-who lived in rural communities of Thailand were randomly recruited.

RESULTS

By using broadband ultrasound attenuation at the cutoff point of mean -1.0 SD based on young Thai people, the independent factors associated with reduced QUS measures in men were: poor activity of daily living, older age, and low fat mass. As for older women, the independent factors were the number of years since menopause, lack of regular exercise, lower height, and low fat mass. When using the stiffness index at the cutoff point of mean -1.6 SD based on young Thai people, the independent factors associated with reduced QUS measures in men were older age and low fat mass. Meanwhile, the number of years since menopause and low lean body mass were independent risk factors in women.

CONCLUSIONS

Poor activity of daily living in men or lack of regular exercise in women was found to be a modifiable risk factor of reduced QUS measures. Years since menopause and low lean body mass were significant factors determining reduced QUS measures in women. Fat mass was an independent factor associated with reduced QUS measures both in men and women.

Reference charts for the relationships between dual-energy X-ray absorptiometry-assessed bone mineral content and lean mass in 3,063 healthy men and premenopausal and postmenopausal women

Correlations between dual-energy X-ray absorptiometry (DXA)-assessed bone mineral content and lean mass (BMC-LM curves), and between BMC/LM ratio and age ([BMC/LM]-age curves), were analyzed in the whole body (WB), the upper limbs (ULs) and the lower limbs (LLs) of 3,063 healthy Hispanic adults. Groups of 472 men aged 25-87 years, 1,035 premenopausal (pre-MP) women aged 27-54 years, and 1,556 post-menopausal (post-MP) women aged 48-93 years were studied with a GE-Lunar DPX-Plus device. BMC-LM curves confirmed previous observations that BMC and LM masses always correlate linearly, with similar slopes within each region, but differing in intercepts according to gender and hormonal status. Multiple regression tests showed little or no independent interaction of body weight or height with those relationships. [BMC/LM]-age curves were flat in men but showed the positive influence of estrogens throughout the age range in women. Z-scored graphs of all the corresponding relationships were compiled, showing the confidence intervals for means +/-1, +/-2, and +/-3 SDs of the data (+/-1, +/-2, +/-3 z-scores) along BMC-LM and [BMC/LM]-age curves. These charts are proposed as references for assessing how well bone mass (as assessed by BMC) and muscle mass (assumed proportional to LM) follow the natural anthropometric/biomechanical proportionality in Hispanic men and women within the age range studied, employing similar devices. Charts for LLs, showing the lowest variance amongst the studied correlations and approaching the origin as an exclusive feature, could provide the most accurate reference curves. Differences between data from ULs and LLs may provide information about any eventual interaction of body-weight bearing with the general results. The proposed analysis may provide useful information for approaching a differential diagnosis between disuse-related and other types of osteopenias employing only DXA.

Contribution of lean tissue mass to the urban-rural difference in bone mineral density

While the urban-rural difference in bone mineral density (BMD) has been shown in some, but not all, Western populations, such a difference and the reason for the difference is largely unknown, particularly in developing countries. This cross-sectional, epidemiologic study was designed to examine the hypothesis that differences in measures of body composition such as lean mass (LM) and fat mass (FM) contribute to the urban-rural difference in BMD. Lean mass, fat mass, lumbar spine and femoral neck BMD were measured by DXA (GE Lunar Corp, Wis.) in 411 urban (Bangkok city) and 436 rural (Khon Kaen province) Thai subjects, aged 20-84 years. Rural men and women had significantly higher LM and lower FM than their urban counterparts. In multiple linear regression analysis, age, LM, menopausal status (in women) and residence were independent determinants of BMD. After adjusting for age, menopause and LM, rural subjects were found to have significantly higher femoral neck BMD, but not lumbar spine BMD, than urban subjects. Furthermore, to alleviate the potential effect of multicolinearity of LM and FM, each rural subject was matched with each urban subject for FM and age, which resulted in 46 pairs of men and 91 pairs of women. In this matched-pair analysis, the femoral necks in rural men and women were, respectively, 7.3+/-2.1% (mean+/-SE; P<0.01) and 6.3+/-2.8% (P<0.02) higher than in urban men and women. The urban-rural difference in LM accounted for approximately 23 and 5% of the urban-rural difference in femoral neck BMD in men and women, respectively. These data are thus consistent with the hypothesis that the urban-rural difference in BMD at a weight-bearing site is in part associated with the urban-rural difference in lean mass.

Effect of different preparations of hormone therapy on lipid and glucose metabolism, coagulation factors, and bone mineral density in overweight and obese postmenopausal women

OBJECTIVE

To determine the effects of different preparations of hormone therapy (HT) on lipid and glucose metabolism, coagulation factors, and bone mineral density (BMD) in overweight and obese postmenopausal women.

DESIGN

A randomized, nonblinded, controlled study.

SETTING

Karadeniz Technical University, Department of Obstetrics and Gynecology.

PATIENT(S)

A total of 352 overweight and obese (body mass index >25 kg/m2) postmenopausal women.

INTERVENTION(S)

Ninety women received 2.5 mg of tibolone; 84 received 2 mg of E2 plus 1 mg of norethisterone acetate (E2/NETA); 90 received 0.625 mg of conjugated equine estrogen plus 2.5 mg of medroxyprogesterone acetate (CEE/MPA); and 88 did not receive any menopausal therapy (control).

MAIN OUTCOME MEASURE(S)

At baseline and after 6 months of treatment, we measured total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), insulin, glucose, factor VII, factor VIII, von Willebrand factor, antithrombin III, protein S, protein C, fibrinogen, and BMD at the lumbar spine L1-L4.

RESULT(S)

There were no statistically significant differences among the groups for any variables at baseline. After 6 months of treatment, the three regimens decreased total cholesterol, triglyceride, LDL, and fibrinogen; E2/NETA and CEE/MPA increased HDL, and tibolone decreased HDL; higher insulin concentrations were found in the control and tibolone groups. Body mass index, HDL, fibrinogen levels, and L1-L4 BMD were independent factors in the prediction of HT use.

CONCLUSION(S)

Body mass index, HDL, fibrinogen levels and L1-L4 BMD were independent factors in the prediction of HT use. Treatment with tibolone, E2/NETA, and CEE/MPA resulted in minimal improvement in lumbar spine BMD but had a beneficial effect on the procoagulation system, with minimal changes in glucose metabolism after 6 months of therapy.

Abdominal fat and hip fracture risk in the elderly: the Dubbo Osteoporosis Epidemiology Study

Background

Fat mass, which is a major component of body weight, is directly related to bone mineral density and reduced fracture risk. It is not known whether abdominal fat is associated with hip fracture. The present study was designed to examine the association between abdominal fat and hip fracture in women and men aged 60+ years.

Methods

This was a nested case-control study with one fracture case being matched with two controls of the same age. In women 63 cases were matched with 126 controls, and in men 26 cases were matched with 52 controls. Hip fracture was confirmed by X-ray and personal interview. Other measurements included weight, height, body mass index (BMI), abdominal fat, and femoral neck bone density (FNBMD). Conditional logistic regression model was used to analyse data.

Results

The odds ratio of hip fracture risk associated with each 10% lower abdominal fat was 1.5 (95% CI, 1.1 to 2.1) in women and 1.2 (95% CI, 0.7 to 2.0) in men. However after adjusting for FNBMD or body weight, the abdominal fat-fracture association was no longer statistically significant. Similarly, body weight and BMI was each significantly associated with hip fracture risk (in women), but after taking with account the effect of FNBMD, the association become statistically non-significant.

Conclusion

Lower abdominal fat was associated with an increased risk of hip fracture in elderly women, but the association was not independent of FNBMD or weight. The contribution of abdominal fat to hip fracture risk is likely to be modest.