The associations of body composition and fat distribution with bone mineral density in elderly Italian men and women

Longitudinal association between muscle and bone loss: Results of US and Japanese cohort studies

BACKGROUND

Muscle and bone are physiologically interconnected, but joint changes of muscle and bone with aging, and whether the muscle-bone changes are different by sex and by country has been little studied. We examined longitudinal associations of bone mineral density (BMD) and muscle mass or muscle strength in community-dwelling 65 years or older in the United States and Japan.

METHODS

The present analytic sample included 1129 women and men from the Baltimore Longitudinal Study of Aging (BLSA) (mean age, 74.5 ± 7.5 years; women, 49.8%) and 1998 women and men from the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) (mean age, 70.0 ± 4.5 years; women, 51.4%). Median follow-up was 4.6 (min-max, 0-15.4) years in the BLSA and 4.0 (min-max, 0-13.4) years in the NILS-LSA. We selected visits at which participants had BMD (whole body, pelvic, femoral neck, trochanter, and Ward's triangle BMDs) and muscle mass [appendicular lean mass, (ALM)] measured by DXA scan. In each bone site, we ran cohort-specific bivariate linear mixed-effects models adjusted for baseline age, sex, body height, body weight, fat mass, education year, and smoking status. Race was an additional adjustment in the BLSA. Additionally, we performed sex-specific analyses.

RESULTS

In the BLSA, the rate of change in ALM positively correlated with the rate of change in the whole body (rho = 0.30, P < 0.0001) and pelvic BMD (rho = 0.24, P < 0.0001), but not in trochanter, femoral neck, or Ward's triangle BMD (P > 0.05). In the NILS-LSA, ALM positively correlated with the rate of change in all bone sites (rho ranged from 0.20 to 0.71, P < 0.01). In women, ALM positively correlated with the rate of change in all bone sites in both cohorts (in the NILS-LSA, rho ranged from 0.35 to 0.91, P < 0.01; in the BLSA, rho ranged from 0.26 to 0.56, P < 0.05) except for femoral neck BMD in the BLSA. In men, ALM positively correlated with pelvic, trochanter, and Ward's triangle BMD in the NILS-LSA (rho ranged from 0.45 to 0.68, P < 0.0001), and whole body and trochanter BMD in the BLSA (both, rho = 0.20, P < 0.05).

CONCLUSIONS

Muscle loss co-occurred with bone loss in both cohorts, but the association in the NILS-LSA tended to be stronger than in the BLSA, and the association was higher in women than in men, implying that the association may differ by sex and country.

The association between body fat distribution and bone mineral density: evidence from the US population

OBJECTIVE

To investigate the association between different body fat distribution and different sites of BMD in male and female populations.

METHODS

Use the National Health and Nutrition Examination Survey (NHANES) datasets to select participants. The weighted linear regression model investigated the difference in body fat and Bone Mineral Density (BMD) in different gender. Multivariate adjusted smoothing curve-fitting and multiple linear regression models were used to explore whether an association existed between body fat distribution and BMD. Last, a subgroup analysis was performed according to age and gender group.

RESULTS

Overall, 2881 participants were included in this study. Compared to males, female participants had lower BMD (P < 0.05) and higher Gynoid fat mass (P < 0.00001), while there was no difference between Android fat mass (P = 0.91). Android fat mass was positively associated with Total femur BMD (Males, β = 0.044, 95% CI = 0.037, 0.051, P < 0.00001; Females, β = 0.044, 95% CI = 0.039, 0.049, P < 0.00001), Femoral neck BMD (Males, β = 0.034, 95% CI = 0.027, 0.041, P < 0.00001; Females, β = 0.032, 95% CI = 0.027, 0.037, P < 0.00001), and Total spine BMD (Males, β = 0.036, 95% CI = 0.029, 0.044, P < 0.00001; Females, β = 0.025, 95% CI = 0.019, 0.031, P < 0.00001). The Gynoid fat mass, subgroup analysis of age and ethnicity reached similar results.

CONCLUSION

Body fat in different regions was positively associated with BMD in different sites, and this association persisted in subgroup analyses across age and race in different gender.

Fat Mass Has Negative Effects on Bone, Especially in Men: A Cross-sectional Analysis of NHANES 2011-2018

CONTEXT

The effect of high levels of obesity on bone health are not clear.

OBJECTIVE

We aimed to examine the associations of body composition and bone mineral density (BMD) in a large, nationally representative population with a wide range of body mass index.

METHODS

We analyzed 10 814 subjects aged 20-59 from NHANES 2011-2018 who had total body BMD and body composition data. Body composition was examined as lean mass index (LMI) and fat mass index (FMI). Linear regression models were created with BMD as the outcome, while examining LMI and FMI and controlling for age, gender, race/ethnicity, height, and smoking status.

RESULTS

In multivariable modeling, every 1 kg/m2 additional LMI was associated with 0.19 higher T-score, while every additional 1 kg/m2 in FMI was associated with 0.10 lower T-score (P < .001 for both). The negative association of FMI with BMD was mainly seen when adjusting for LMI. Effects of LMI were similar in men and women, but the effect of FMI was more negative in men (0.13 lower T-score per additional 1 kg/m2 of FMI in men vs 0.08 lower BMD T-score in women, P for interaction < .001).

CONCLUSION

In subjects under 60 years old, lean mass had a strong positive association with BMD. Conversely, fat mass had a moderate, negative association with BMD that was most notable in men at high levels of fat. Our results emphasize the importance of bone health in obesity and may explain site-specific increases in fracture rates in some studies of obese subjects.

Does Unilateral Lumbosacral Radiculopathy Affect the Association between Lumbar Spinal Muscle Morphometry and Bone Mineral Density?

Age-related degenerative changes lead to a gradual decrease in bone mineral density (BMD) and muscle mass. We aimed to assess the effects of decreased BMD and lumbar denervation on lumbar spinal muscle morphometry and the relationship between BMD and lumbar spinal muscular morphometry, respectively. Eighty-one patients, aged 50–85 years, diagnosed with unilateral lumbosacral radiculopathy based on electrodiagnostic studies between January 2016 and April 2021 were enrolled. BMD T scores in the lumbar spine and hip were measured using dual-energy X-ray absorptiometry. The cross-sectional area (CSA) of the psoas, multifidus, and erector spinae located in the middle of the lumbar spine, between the L3 and L4 and between the L4 and L5 levels, respectively, was measured using axial MRI. Functional CSA (FCSA) was defined as the CSA of lean muscle mass. Pearson correlation analyses were performed to evaluate the association between BMD T scores and the CSA, FCSA, and the ratio of the FCSA to the CSA (functional ratio) for each side. The CSA of lumbar spinal muscles showed no significant correlation with lumbar BMD. The FCSA and functional ratio of lumbar spinal muscles were significantly correlated with lumbar BMD. There was no correlation between femur BMD and lumbar spinal muscle morphometry.

Influence of the appendicular skeletal muscle mass index on the bone mineral density of postmenopausal women

BACKGROUND

The appendicular skeletal muscle mass index (ASMI) is an important risk indicator for osteoporosis because of the anatomical proximity and metabolic connection between muscle and bone mass. The present study investigated the relationship between ASMI and the bone mineral density (BMD) categories of postmenopausal women.

METHODS

In this cross-sectional study with a probabilistic sample, sociodemographic, lifestyle, menopause time, anthropometric, and physical activity variables were collected. ASMI and BMD were assessed by dual-energy X-ray absorptiometry (DXA). Participants were grouped according to BMD values into normal density, osteopenia, and osteoporosis. Multivariate logistic regression models were applied to verify the influence of ASMI on BMD. Data were analyzed using the SPSS statistical software, version 22. The significance level for all tests was set at 5%.

RESULTS

Of the 114 women analyzed, most were between 60 and 69.9 years of age (62.3%), on menopause for ≤19.0 (51.8%), self-declared brown race/color (49.1%), had < 4 years of education (41.2%), never smoked (69.0%) or drank alcohol (62.8%). Of these, 52.6% were classified as sufficiently active and 52.2% had regular sun exposure. Women with osteoporosis were older (p = 0.035), on menopause for a longer time (p = 0.011), underweight (p = 0.004), had adequate waist circumference (p = 0.017), and low ASMI values (p = 0.002). There was an association between the 1st tertile of ASMI and osteoporosis. However, after adjustments for age, race/color, and body mass index, the strength of association between BMD and ASMI was not maintained.

CONCLUSIONS

ASMI was not associated with the BMD of the postmenopausal women evaluated. Total body and muscle mass, in addition to bone mass, should be monitored during menopause treatment. Longitudinal studies must be conducted to elucidate the mechanisms and gaps in this relationship.

Predicting osteoporosis with body compositions in postmenopausal women: a non-invasive method

Background

The prevalence of osteoporosis is rising steadily as the aging population increases. Bone mineral density (BMD) assessment is a golden standard to establish the diagnosis of osteoporosis. However, the accessibility and radiation exposure limited its role in community screening. A more convenient approach for screening is suggested.

Methods

A total of 363 postmenopausal women over the age of 50 were included in this study and assessed with the body composition [including fat-free mass (FFM), fat mass (FM), and basal metabolic rate (BMR)] and BMD. Normal distributions and correlation coefficients among variables were calculated using the Shapiro-Wilk test and Pearson’s correlation analysis, respectively. A receiver operating characteristic (ROC) curve was plotted, and the area under ROC curves (AUC) was determined to obtain the optimal cutoff values of the body composition variables for osteoporosis prediction.

Results

The correlation coefficient of FFM, FM, FM ratio, and BMR with femur neck T-score was 0.373, 0.266, 0.165, and 0.369, respectively, while with spine T-score was 0.350, 0.251, 0.166, and 0.352, respectively (p < 0.01 for all). FFM, FM, and BMR showed an optimal cutoff value of 37.9 kg, 18.6 kg, and 1187.5 kcal, respectively, for detecting osteoporosis.

Conclusions

The present study provided a model to predict osteoporosis in postmenopausal women, and the optimal cutoff value of FFM, FM, and BMR could be calculated in the Asian population. Among these factors, BMR seemed a better predictor than others. The BMR could be a target for exercise intervention in postmenopausal women for maintaining or improving BMD.

Trial registration

ClinicalTrials.gov, NCT02936336. Retrospectively registered on13 October 2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02351-3.

General and central obesity operate differently as predictors of falls requiring medical care in older women: a population-based cohort study in Spain

OBJECTIVES

to examine the association of general and abdominal obesity with falls, falls requiring medical care and falls with fractures in older women.

DESIGN

a population-based prospective cohort of 1,185 women aged ≥60 in Spain, followed up from 2008 to 2010 through 2012.

MEASURES

weight, height and waist circumference were measured at baseline using standardised techniques. Participants were classified according to body mass index as normal weight (<25), overweight (25-29.9) and general obesity (≥30). Abdominal obesity was defined as waist circumference >88 cm. In 2012, participants reported the falls experienced in the previous year. Logistic regression models were mutually adjusted for general and abdominal obesity and for main confounders.

RESULTS

in this cohort of older women, a total of 336 women experienced falls, 168 of them had falls requiring medical care and 64 falls with fractures. For falls, no association was found with general obesity nor abdominal obesity. However, compared with normal weight, overweight women had a decreased risk for falls requiring medical care [odds ratio (OR) 0.57; 95% confidence interval (CI) 0.34-0.94] and for falls with fractures (OR 0.27; 95% CI 0.12-0.63). The corresponding values for general obesity were 0.44 (0.24-0.81) and 0.30 (0.11-0.82). Abdominal obesity was positively associated with falls requiring medical care (OR 1.82; 95% CI 1.12-2.94) and falls with fractures (OR 2.75; 95% CI 1.18-6.44).

CONCLUSIONS

in older women, general obesity may protect from falls requiring medical care and falls with fractures. On the contrary, abdominal obesity increased the risk of suffering from types of falls.

Obesity, dynapenia, and their combination: Implications for bone mineral density in Brazilian adults-the Pró-Saúde study

OBJECTIVES

This study aimed to evaluate bone mineral density (BMD) in the presence or absence of dynapenia or obesity in Brazilian adults.

METHODS

This is a cross-sectional study conducted in 502 adults (age: 33-81 y; 51% women) participating in the Pró-Saúde study, a cohort of civil servants at the university campuses in Rio de Janeiro, Brazil. Body composition and BMD were determined by dual energy x-ray absorptiometry. Handgrip strength was measured using a dynamometer. According to measures of handgrip strength (≤19 kg for women; ≤32 kg for men) and fat mass (>30% for men; >40% for women), participants were classified into four groups: non-obese non-dynapenic, obese non-dynapenic, non-obese dynapenic, and obese dynapenic. The association between BMD at each specific bone site and obesity, dynapenia, and their interaction was evaluated using a general linear model.

RESULTS

The prevalence of dynapenic obesity was 14% in men and 15.2% in women. Dynapenia alone was not associated with BMD at any site in either men nor women. Obesity and dynapenia interacted to influence BMD in women (P < 0.05). Total body, lumbar spine, and femoral neck BMD were higher by 6.3%, 9.3%, and 10.4%, respectively, in dynapenic obese women compared with their non-obese counterparts (P < 0.05). In men, obesity, dynapenia, and their combination were not associated with BMD at any site.

CONCLUSIONS

Our results suggest that dynapenia, obesity, and their combination may affect BMD in a sex-dependent manner. In the presence of dynapenia, fat mass appears to exert a protective effect on BMD in women, but not in men.

Relationships between bone mineral density, body composition, and isokinetic strength in postmenopausal women

Objectives

The increase in body fat mass (BFM) and the loss of lean body mass (LBM) or muscle strength with age affects bone mineral (BMD). These factors increase the prevalence and incidence of obesity and sarcopenia, which have unclear effects on bone mineral density. The purpose of this study was to determine how the above selected factors affect BMD.

Methods

A cross-sectional study was conducted involving 58 women (aged 62.1 ± 4.8 years). Total body, left proximal femur, lumbar spine BMD, and body composition parameters were measured with dual-energy x-ray absorptiometry. Isokinetic flexion and extension strength of the dominant leg were measured at 60 deg./s. Grip strength was measured with the dominant upper extremity. To determine the volume of physical activity (PA), the PA level was monitored for seven consecutive days using an ActiGraph model GT1M accelerometer.

Results

BFM was positively associated with BMD of the proximal femur (β = 0.31; P < 0.05), whereas LBM or appendicular lean mass (ALM) did not relate to BMD at any sites. Dominant isokinetic strength also did not relate to BMD at any site. A/G (android/gynoid) fat ratio shows positive association with lumbar spine BMD after adjusting for YSM (years since menopause), height, smoking status, and steps per day.

Conclusion

We observed a positive association between proximal femur BMD and BFM, but not between LBM, ALM or isokinetic strength. A/G ratio and BMI showed a positive association with lumbar spine BMD or proximal femur BMD, respectively.

Relationship of Two-Hour Plasma Glucose and Abdominal Visceral Fat with Bone Mineral Density and Bone Mineral Content in Women with Different Glucose Metabolism Status

BACKGROUND

Several studies have reported the relationship of diabetes mellitus (DM) and obesity with bone mineral density (BMD), but the conclusions remain unclear. This study aimed to provide more information for the relationship of plasma glucose and abdominal visceral fat (AVF) with BMD and bone mineral content (BMC) in women with different glucose metabolism status.

METHODS

Patients were screened by oral glucose tolerance test (OGTT) and were divided into three groups: normal glucose tolerance (NGT, n=132), pre-diabetes mellitus (pre-DM, n=28) and newly diagnosed type 2 DM (T2DM, n=27) groups. Plasma glucose concentrations, anthropometric measurements, body composition, and BMD were measured. Analysis of variance (ANOVA), pearson correlation, and multiple linear regression models were used to evaluate the relationship between BMD, plasma glucose, AVF, and other variables.

RESULTS

The percentage of subjects with osteoporosis or low BMD was 29.9%, and 66.7% subjects in T2DM group were significantly higher than that in the pre-DM (28.6%) and NGT (22.7%) groups (p=0.005 and p<0.001, respectively). Both BMD at femoral neck (FN) and lumbar spine (LS) of T2DM group were lower than those in NGT group (p=0.009 and p=0.003, respectively), and BMC of T2DM group was lower than those of NGT and pre-DM groups (p<0.001). The results of statistical analysis revealed that both two-hour plasma glucose (2-h PG) and age showed negative correlation with BMC, FN BMD, and LS BMD. AVF showed positive correlation with BMC and LS BMD. Furthermore, the lean mass (LM) showed independent positive effects on BMC.

CONCLUSION

Our findings suggest that 1) Age is a strong negative predictor of bone mass. 2) A direct negative effect of increasing 2-h PG might be more prominent at bone mass in women. 3) A moderate increase in AVF is beneficial to bone mass, while excessive increase might be harmful. 4) LM is a positive predictor of BMC.

Contribution of Android and Gynoid Adiposity to Bone Mineral Density in Healthy Postmenopausal Thai Women

Dual-energy X-ray absorptiometry (DXA) is one of the major tools for assessing the whole body and regional body composition and body adiposity. Various body composition parameters including android fat mass (AFM), gynoid fat mass (GFM), and android-to-gynoid fat ratio (AG fat ratio) obtained from whole body DXA can be used as a reliable surrogate marker for regional body composition analysis. This study aimed to explore the contribution of android and gynoid adiposity to bone mineral density (BMD) in healthy postmenopausal Thai women. This cross-sectional study enrolled 1448 healthy Thai women, ages 40-90 without medication history or known disease affecting the BMD. Lumbar spine (LS), total femur, and femoral neck BMDs, AFM, GFM, and AG fat ratio were measured by DXA. To evaluate the contribution of android and gynoid adiposity with various measures of BMDs, univariable and multivariable linear regression analyses were used to estimate the regression coefficients. AFM, GFM, and AG fat ratio had a significant positive association with BMD of all measured sites (p < 0.001) in the univariate analysis. The strongest association was found between AG fat ratio and LS BMD (β = 0.156, p ≤ 0.001). In multivariate linear regression analysis, the results continued to show a positive association between AFM and GFM at all skeletal sites after adjusting for age, height, and total body lean mass. Relationship between AG fat ratio and BMD was found only in LS region. GFM had a strongest positive effect with BMD at the LS, total femur, and femoral neck regions. Higher android and gynoid adiposity was associated with higher BMD. GFM rather than AFM shows the strongest positive association with BMDs in postmenopausal Thai women.

Body mass estimation from the skeleton: An evaluation of 11 methods

Estimating an individual body mass (BM) from the skeleton is a challenge for forensic anthropology. However, identifying someone's BMI (Body Mass Index) category, i.e. underweight, normal, overweight or obese, could contribute to identification. Individual BM is also known to influence the age-at-death estimation from the skeleton. Several methods are regularly used by both archaeologists and forensic practitioners to estimate individual BM. The most commonly used methods are based on femoral head breadth, or stature and bi-iliac breadth. However, those methods have been created from mean population BMs and are therefore meant to estimate the average BM of a population. Being that they are based on individual BM data and estimated femoral cortical areas, the newest published methods are supposed to be more accurate. We evaluated the accuracy and reliability of the most commonly used and most recent BM estimation methods (n=11) on a sample of 64 individuals. Both sexes and all BMI categories are represented, as well as a wide range of BM. Ages in this sample range from 20 to 87 years of age. Absolute and real differences between actual BM and estimated BM were assessed; they determined the accuracy for individual BM estimation and for average BM estimation of a population, respectively. The proportion of the sample whose estimated BM falls within ±10% and ±20% of their actual BM determines the reliability of the methods in our sample for, respectively, individual BM estimation and average BM of a population. The tested methods result in an absolute difference of 11kg-26kg±10kg with regards to prediction of individuals actual BM. The real differences are very variable from method to method, ranging from -14kg to 25kg. None of the tested methods is able to estimate BM of half of the sample within ±10% of their actual BM but most of them can estimate BM of more than half of the sample within ±20% of their actual BM. The errors increase with increasing BM, demonstrating a bias in all the methods. No bone variable tested correlated with BM. BMI categories were correctly predicted for less than 50% of the sample in most cases. In conclusion, our study demonstrates that the 11 methods tested are not suited for estimating individual BM or for predicting BMI categories. However, they are accurate and reliable enough for estimating the average BM of a population.

A systematic review of vitamin D status in southern European countries

PURPOSE

Despite an acknowledged dearth of data on serum 25-hydroxyvitamin D (25(OH)D) concentrations from Southern European countries, inter-country comparison is hampered by inconsistent data reporting. The purpose of the current study was to conduct a systematic literature review of available data on serum 25(OH)D concentrations and estimate vitamin D status in Southern European and Eastern Mediterranean countries, both at a population level and within key population subgroups, stratified by age, sex, season and country.

METHODS

A systematic review of the literature was conducted to identify and retrieve scientific articles reporting data on serum 25(OH)D concentration and/or vitamin D status following standard procedures.

RESULTS

Data were extracted from 107 studies, stratified by sex and age group, representing 630,093 individuals. More than one-third of the studies reported mean 25(OH)D concentrations below 50 nmol/L and ~ 10% reported mean serum 25(OH)D concentrations below 25 nmol/L. Overall, females, neonates/ infants and adolescents had the higher prevalence of poor vitamin D status. As expected, there was considerable variability between studies. Specifically, mean 25(OH)D ranged from 6.0 (in Italian centenarians) to 158 nmol/L (in elderly Turkish men); the prevalence of serum 25(OH)D < 50 nmol/L ranged from 6.8 to 97.9% (in Italian neonates).

CONCLUSIONS

Contrary to expectations, there was a high prevalence of low vitamin D status in the Southern Europe and the Eastern Mediterranean regions, despite abundant sunshine. These data further emphasize the need for strategies, such as fortification of foods with vitamin D and/or vitamin D supplementation, which will be tailored to the needs of specific population groups with higher risk of insufficiency or deficiency, to efficiently tackle the pandemic of hypovitaminosis D in Europe.

Association between fat mass and bone mineral density among Brazilian women differs by menopausal status: The Pró-Saúde Study

OBJECTIVE

The aim of this study was to investigate the association between bone mineral density (BMD) and fat mass (FM) in a multiethnic population of Brazilian women and to evaluate the influence of total body mass and lean mass on this association.

METHODS

This was a cross-sectional study nested within the Pro-Saúde Study, a prospective cohort of university civil servants in Rio de Janeiro. Participants were pre- (n = 100) and postmenopausal (n = 166) women. Total fat, lean mass, and BMD of total body, lumbar spine, and femoral neck were measured using dual energy x-ray absorptiometry. The association of BMD with FM was investigated after adjustment for total body mass (model 1) and lean mass (model 2) and potential confounding variables using multivariate linear regression models.

RESULTS

In model 1, FM was inversely associated with BMD for total body (B = -0.010; P < 0.01) and for femoral neck (B = -0.009 P < 0.05) in premenopausal women. No association between FM and BMD was observed in postmenopausal women. Model 2 yielded direct associations between FM and BMD (total and specific sites; B = 0.003-0.008; P < 0.01) in postmenopausal women only.

CONCLUSIONS

Independently of the adjustment used, the results of the present study suggest the absence of an inverse association between FM and BMD in postmenopausal women. Additionally, when adjusted for lean mass, a direct association between FM and bone mass can be observed, suggesting that for postmenopausal women being slightly obese does not confer excessive risk for bone loss and may even result in a bone density advantage.

Idiopathic pulmonary fibrosis a rare disease with severe bone fragility

Idiopathic pulmonary fibrosis (IPF) is a rare form of chronic, progressive fibrosing interstitial pneumonia of unknown cause. The aim of this cross-sectional study was to assess the prevalence of osteoporosis and fragility fracture in a population of adults with IPF and to identify whether any possible clinical and pulmonary function parameters may be associated with increased bone fragility. In 58 IPF patients (mean age 65.1 ± 9.1 years), we measured bone mineral density (BMD) of the lumbar spine, the femoral neck, and the entire hip. Moreover, the presence of vertebral fractures on a lateral chest X-ray study was evaluated, and a vertebral fracture burden was quantified using the spinal deformity index (SDI). As expected, osteoporosis was significantly more frequent in females with respect to males (57.9 vs 20.5 %, respectively), whereas the fractures prevailed in males with respect to females (38.5 vs 26.3 %, respectively). There were positive correlations between BMD at all skeletal sites and respiratory parameters; in particular for FVC % and DLCO % with BMD at femoral sub-regions. Moreover, we compared the average of DLCO (%) measure by values of SDI score that was higher in those patients with lower values of DLCO (%). The study shows a high prevalence of fragility with vertebral fractures in IPF patients, especially in males. Moreover, the vertebral fracture burden is associated with a worsening of FVC (%) and DLCO (%). Therefore, an evaluation of bone status is recommended, especially in those patients who are candidates for lung transplantation.

Assessment of trabecular bone score (TBS) in overweight/obese men: effect of metabolic and anthropometric factors

The "trabecular bone score" (TBS) indirectly explores bone quality, independently of bone mineral density (BMD). We investigated the effects of anthropometric and metabolic parameters on TBS in 87 overweight/obese men. We assessed BMD and TBS by DXA, and some parameters of glucose metabolism, sex-and calciotropic hormone levels. Regression models were adjusted for either age and BMI, or age and waist circumference, or age and waist/hip ratio, also considering BMI >35 (y/n) and metabolic syndrome (MS) (y/n). Correlations between TBS and parameters studied were higher when correcting for waist circumference, although not significant in subjects with BMI >35. The analysis of covariance showed that the same model always had a higher adjusted r-square index. BMD at lumbar spine and total hip, fasting glucose, bioavailable testosterone, and sex hormone-binding globulin are the only covariates having a significant effect (p < 0.05) on the variations of TBS. The presence of MS negatively affected only the association between TBS and BMD at total hip. We did not find any significant effect of BMI >35 on TBS values or significant interaction terms between each covariate and either BMI >35 or the presence of MS. Obesity negatively affected TBS, despite unchanged BMD. Alterations of glucose homeostasis and sex hormone levels seem to influence this relationship, while calciotropic hormones have no role. The effect of waist circumference on TBS is more pronounced than that of BMI.

Relationship between Bone Mineral Density and Spinal Muscle Area in Magnetic Resonance Imaging

Background

Bone mineral density (BMD) is known to have a positive correlation with lean body mass. Several studies have also reported the positive correlation between muscle power and BMD. From this point of view, we hypothesized BMD of lumbar spine to have a positive correlation with muscle mass.

Methods

Seventy-nine female patients aged between 60 and 75 years old and who underwent magnetic resonance imaging (MRI) and BMD studies were included. Muscle mass in spine MRI was defined by the sum of the average muscle area of three axial images for each disc level. Lumbosacral muscle is the sum of paraspinal muscle and psoas muscle.

Results

In correlation analysis, paraspinal muscle mass showed positive correlation with BMD of lumbar spine. Lumbosacral muscle mass showed positive correlation with BMD of trochanteric area of the femur. However, BMD of other area showed no significant correlation with muscle mass.

Conclusions

Therefore, postmenopausal women older than 60 years with a well developed spine muscle mass, have a high BMD.

Lean mass in obese adult subjects correlates with higher levels of vitamin D, insulin sensitivity and lower inflammation

AIM

Several chronic metabolic alterations are present in obese subjects. While it is well known about the detrimental effect of abdominal adipose tissue on chronic metabolic clinical condition, less is known on the role of lean mass in obese subjects. Thus, the aim of our study was to evaluate the potential correlation of muscle mass, metabolic condition and inflammation status in obese individuals.

METHODS

The study included 426 obese subjects (86 men and 340 female; mean age 44.8 ± 14 years; BMI: 34.9 ± 6.1 kg/m(2)). Exclusion criteria were chronic medical conditions or use of medications affecting bone metabolism, alterations of hormonal and nutritional status, vitamin D supplementation, recent weight loss and prior bariatric surgery. Patients underwent measurements of bone mineral density (lumbar and hip) and body composition (lean mass, total and trunk fat mass) by dual X-ray absorptiometry and were evaluated for hormonal and metabolic profile and inflammatory markers.

RESULTS

Higher lean body mass (LM%) was inversely correlated with homeostasis model assessment of insulin resistance (p < 0.0091; r(2) 0.03938) and associated with lower fibrinogen levels (p < 0.0001; r(2) 0.1263). Interestingly, in obese subjects, LM% was associated with higher levels of vitamin D (p < 0.0001, r(2) 0.1140), osteocalcin (p < 0.0001, r(2) 0.2401) and insulin-like growth factor-1 (IGF-1) (p < 0.0002, r(2) 0.1367).

CONCLUSION

Our results show for the first time that in obese patients, higher amounts of lean mass are directly linked to a lower inflammatory profile and to better insulin sensitivity, but also to the presence of higher level of vitamin D and IGF-1. Moreover, these data suggest that higher levels of lean mass in obese people correlate with a better metabolic profile and, thus, strongly suggest the need to develop programs to facilitate an increase in physical activity in obese people.

Associations of fat mass and fat distribution with bone mineral density in Chinese obese population

The purpose of the study was to investigate the associations of fat mass (FM) and fat distribution with bone mineral density (BMD) in Chinese obese population. Three hundred and forty-seven Chinese obese females and 339 males aged 20-39 years were analyzed. Lean mass (LM), FM, percent body fat (%BF), android FM, gynoid FM, and total and regional BMD were measured using dual-energy X-ray absorptiometry. Fat distribution was assessed by android-to-gynoid FM ratio (AOI). As a result, increased central body fat had an inverse association with total and leg BMD in females but not in males. Increased FM and %BF were positively associated with arm, trunk, and pelvic BMD in Chinese obese females. Increased FM was positively associated with total, rib, and trunk BMD in Chinese obese males. The results remained almost unchanged after adjusting for LM, and LM was significantly positively associated with spine BMD in female group. FM was positively associated with trunk BMD in male group after adjusting for LM. AOI was inversely associated with total and leg BMD, and %BF was positively associated with arm, trunk, and pelvic BMD when replacing FM with %BF in female group. The results remained almost unchanged after adjusting for LM. There is no significant association in male group when replacing FM with %BF. In conclusion, our findings demonstrate that there are different associations of FM and fat distribution with BMD, and AOI has a negative association with BMD.

Gender-specific associations of appendicular muscle mass with BMD in elderly Italian subjects

Currently used diagnostic measures for sarcopenia are based on the evaluation of appendicular skeletal muscle mass (ASMM) divided by height-squared (ASMMI). This study aimed to investigate the associations between different operational definitions of appendicular muscle mass and BMD at different skeletal sites in aging Italian men and women. In 1199 consecutive healthy Italian subjects, aged 55 years or more (854 women, age 64.2 ± 6.4 years and 165 men, age 65.3 ± 6.1 years), we measured BMD at the lumbar spine (LS-BMD), at femoral neck (FN-BMD),at total hip (TH-BMD), at total body (WB-BMD) and at the right hand (H-BMD) and body composition parameters [ASMM, ASMMI, ASMM/Weight, total lean mass and total fat mass by DXA]. In all subjects, we also measured sex hormones, 25-hydroxyvitamin D and bone turnover markers. In men, both ASMM and ASMMI were positively correlated with BMD at all sites, whereas in women, ASMM and ASMMI did not show any significant correlation with BMD. In men, multiple regression analyses showed that ASMM was positively associated (p < 0.01) with FN-BMD, TH-BMD and H-BMD; however, these associations were no longer present when lean mass was included. In women, both fat mass and lean mass were found positively associated with BMD at all sites. In conclusion, among the different operational measures of the ASMM, only ASMM was significantly associated with BMD in elderly men, but not in elderly women.

Divergent effects of obesity on fragility fractures

Obesity was commonly thought to be advantageous for maintaining healthy bones due to the higher bone mineral density observed in overweight individuals. However, several recent studies have challenged the widespread belief that obesity is protective against fracture and have suggested that obesity is a risk factor for certain fractures. The effect of obesity on fracture risk is site-dependent, the risk being increased for some fractures (humerus, ankle, upper arm) and decreased for others (hip, pelvis, wrist). Moreover, the relationship between obesity and fracture may also vary by sex, age, and ethnicity. Risk factors for fracture in obese individuals appear to be similar to those in nonobese populations, although patterns of falling are particularly important in the obese. Research is needed to determine if and how visceral fat and metabolic complications of obesity (type 2 diabetes mellitus, insulin resistance, chronic inflammation, etc) are causally associated with bone status and fragility fracture risk. Vitamin D deficiency and hypogonadism may also influence fracture risk in obese individuals. Fracture algorithms such as FRAX^® might be expected to underestimate fracture probability. Studies specifically designed to evaluate the antifracture efficacy of different drugs in obese patients are not available; however, literature data may suggest that in obese patients higher doses of the bisphosphonates might be required in order to maintain efficacy against nonvertebral fractures. Therefore, the search for better methods for the identification of fragility fracture risk in the growing population of adult and elderly subjects with obesity might be considered a clinical priority which could improve the prevention of fracture in obese individuals.

Obesity and fracture risk

Obesity and osteoporosis are two common diseases with an increasing prevalence and a high impact on morbidity and mortality. Obese women have always been considered protected against osteoporosis and osteoporotic fractures. However, several recent studies have challenged the widespread belief that obesity is protective against fracture and have suggested that obesity is a risk factor for certain fractures. Fat and bone are linked by many pathways, which ultimately serve the function of providing a skeleton appropriate to the mass of adipose tissue it is carrying. Leptin, adiponectin, adipocytic estrogens and insulin/amylin are involved in this connection. However, excessive body fat, and particularly abdominal fat, produces inflammatory cytokines which may stimulate bone resorption and reduce bone strength. This review aimed to examine the literature data on the relationships of BMI and fat mass with factures in adult and elderly subjects. Even though the more recent studies have shown conflicting results, there is growing evidence that obesity, and particularly severe obesity, may be related to an increased risk of fracture at different skeletal sites which is partially independent from BMD. Moreover, the relationship between obesity and fracture appears to be markedly influenced by ethnicity, gender and fat distribution. Even though the incidence and the pathogenesis of fracture in obese individuals has not yet been clearly defined, the growing evidence that obesity may be related to an increased risk of fracture has important public health implications and emphasizes the need to develop effective strategies to reduce fracture risk in obese subjects.

Effect of basal metabolic rate on the bone mineral density in middle to old age women in Taiwan

BACKGROUND

Basal metabolic rate (BMR) reflects a combination of cardiopulmonary function and lean body mass resulting from regular physical activity. Though many studies have examined the relationships between bone mineral density (BMD) and body composition, little is known regarding the relationship between BMD and BMR.

OBJECTIVE

The purpose of this study was to investigate the relationship between BMR, anthropometric parameters, body composition and BMD in postmenopausal women in Taiwan.

METHODS

Two hundred and eighty-nine women between the ages of 40 and 80 years were included in this cross-sectional study. The following parameters were assessed: height, body weight, total body fat (TBF), BMR, waist-to-hip ratio, grip strength, and back strength. Differences in all variables between osteoporotic and non-osteoporotic women (categorized according to decades in age) were calculated using a one-way analysis of variance (ANOVA) and a Bonferroni post-hoc test. Multiple linear regression with a backward stepwise approach was performed to evaluate the relationship between these measurements and BMD.

RESULTS

Among women over 50 years of age, those who were non-osteoporotic had higher BMR, BMI, and body fat by comparison to their osteoporotic counterparts (p<0.05 for all). Multiple linear regression revealed that BMR and body fat significantly predicted BMD of the femoral neck (adjusted beta coefficients of 0.304 and 0.190, respectively; p<0.05 for both). BMR and body fat also predicted an increased vertebral BMD (adjusted beta coefficients of 0.310 and 0.141, respectively; p<0.05 for both).

CONCLUSION

BMR is closely associated with BMD in elderly persons, and may be a novel target for interventions aimed at preventing the age-related decline in BMD.

Association of weight-adjusted body fat and fat distribution with bone mineral density in middle-aged chinese adults: a cross-sectional study

Background

Although it is well established that a higher body weight is protective against osteoporosis, the effects of body fat and fat distribution on bone mineral density (BMD) after adjustment for body weight remains uncertain.

Objective

To examine the relationship between body fat and fat distribution and BMD beyond its weight-bearing effect in middle-aged Chinese adults.

Method

The study had a community-based cross-sectional design and involved 1,767 women and 698 men aged 50–75 years. The BMD of the lumbar spine, total hip, and whole body, and the fat mass (FM) and percentage fat mass (%FM) of the total body and segments of the body were measured by dual-energy X-ray absorptiometry. General information on the participants was collected using structured questionnaire interviews.

Result

After adjusting for potential confounders, an analysis of covariance showed the weight-adjusted (WA-) total FM (or %FM) to be negatively associated with BMD in all of the studied sites (P<0.05) in both women and men. The unfavorable effects of WA-total FM were generally more substantial in men than in women, and the whole body was the most sensitive site related to FM, followed by the total hip and the lumbar spine, in both genders. The mean BMD of the lumbar spine, total hip, and whole body was 3.93%, 3.01%, and 3.65% (in women) and 5.02%, 5.57%, 6.03% (in men) lower in the highest quartile (vs. lowest quartile) according to the WA-total FM (all p<0.05). Similar results were noted among the groups for WA-total FM%. In women, abdominal fat had the most unfavorable association with BMD, whereas in men it was limb fat.

Conclusion

FM (or %FM) is inversely associated with BMD beyond its weight-bearing effect. Abdominal fat in women and limb fat in men seems to have the greatest effect on BMD.