Percent fat mass is inversely associated with bone mass and hip geometry in rural Chinese adolescents

Impact of leptin deficiency on male tibia and vertebral body 3D bone architecture independent of changes in body weight

Leptin an adipokine with potent effects on energy balance and body weight plays an important role in defining bone architecture in growing mammals. However, major changes in body weight can also influence morphology of trabecular and cortical bone. Therefore, we examined the impact of leptin deficiency on tibia and vertebral body 3D bone architecture independent of changes in body weight. Furthermore, advances in computational 3D image analysis suggest that average morphological values may mask regional specific differences in trabecular bone thickness. The study utilized leptin-deficient Ob/Ob mice (n = 8) weight-paired to C57BL/6 (C57) control mice (n = 8) which were split into either lean or obese groups for 24 ± 2 weeks. Whole tibias and L3 vertebrae were fixed before high resolution microcomputed tomography (μCT) scanning was performed. Leptin deficiency independent of body weight reduced tibia cortical bone volume, trabecular bone volume/tissue volume, number, and mineral density. Mean tibia trabecular thickness showed no significant differences between all groups; however, significant changes in trabecular thickness were found when analyzed by region. This study demonstrates that leptin deficiency significantly impacts tibia and vertebral body trabecular and cortical bone 3D architecture independent of changes in body weight.

Associations of Three-Dimensional Anthropometric Body Surface Scanning Measurements and Coronary Artery Disease

Background and Objectives: The relationship between three-dimensional (3D) scanning-derived body surface measurements and biomarkers in patients with coronary artery disease (CAD) were assessed. Methods and Methods: The recruitment of 98 patients with CAD confirmed by cardiac catheterization and 98 non-CAD patients were performed between March 2016 and December 2017. A health questionnaire on basic information, life style variables, and past medical and family history was completed. 3D body surface measurements and biomarkers were obtained. Differences between the two groups were assessed and multivariable analysis performed. Results: It was found that chest width (odds ratio [OR] 0.761, 95% confidence interval [CI] = 0.586–0.987, p = 0.0399), right arm length (OR 0.743, 95% CI = 0.632–0.875, p = 0.0004), waist circumference (OR 1.119, 95% CI = 1.035–1.21, p = 0.0048), leptin (OR 1.443, 95% CI = 1.184–1.76, p = 0.0003), adiponectin (OR 0.978, 95% CI = 0.963–0.994, p = 0.006), and interleukin 6 (OR 1.181, 95% CI = 1.021–1.366, p = 0.0254) were significantly associated with CAD. The combination of biomarker scores and body measurement scores had the greatest area under the curve and best association with CAD (area under the curve of 0.8049 and 95% CI = 0.7440–0.8657). Conclusions: Our study suggests that 3D derived body surface measurements in combination with leptin, adiponectin, and interleukin 6 levels may direct us to those at risk of CAD, allowing a non-invasive approach to identifying high-risk patients.

Adiposity is not beneficial to bone mineral density in 0-5 year old Chinese children: The Jiangsu bone health study

OBJECTIVE

Data on obesity in relation to bone mineral density(BMD) in infants and preschool children were sparse in China. The objective of this study was to examine the associations between body mass index (BMI) and BMD.

SUBJECTS AND METHODS

This was a large population-based multicenter study in which the representative children aged 0-5 years were recruited from 13 Children's Health Care Centers by a stratified cluster random-sampling method in Jiangsu Province, China. BMD was measured by using quantitative ultrasound. The association of BMD with BMI and obesity were evaluated using multiple linear regression and logistic regression analysis taking into account the effects of confounders. The relations between age, weight, height, BMI and BMD were analyzed by using Pearson's correlation and further tested using partial correlation in the additive model.

RESULTS

A total of 5,289 children (2786 boys and 2503 girls) were recruited. The BMD was positively linear relation with age, length/height, and was inversely linear relation with BMI (r=0.711, P<0.001; r=0.727, P<0.001; r=-0.318, P<0.001, respectively). The BMD gradually increased when the weight was in the range within 21.2kg, but started to gain slowlyand even decreased when the weight was over 21.2kg. After adjusting for confounders, compared with control group, children with obesityhad higher odds of low BMD (OR 95%CI: 2.73 (1.57, 4.76), P<0.001), the speed of sound (SOS)value in children with obesity was lower 47.45 (β=-47.45, 95%CI=-85.07, -9.83, P=0.013).

CONCLUSIONS

Adiposity was not advantageous for bone mineral density in 0-5-year-old Chinese children.

Association of body composition with predicted hip bone strength among Chinese postmenopausal women: a longitudinal study

Body composition and bone strength are closely associated. How lean mass (LM) and fat mass (FM) contribute to bone strength remains ambiguous. We investigated the associations of total body LM and FM with changes in predicted hip bone strength over a period of 3 years in 1,743 postmenopausal Chinese women from the communities of Guangzhou, China. The body compositions of the women were obtained with dual-energy X-ray absorptiometry. We used the hip structure analysis program to obtain the bone parameters at the femoral neck region, including the bone mineral density (BMD), cross-sectional area (CSA), cortical thickness (CT), section modulus (SM) and buckling ratio (BR). We found the FM and LM were positive predictors for hip bone strength (β > 0, P < 0.05). The LM had a larger contribution to the BMD, CSA, CT, SM and/or their annual percent changes (βLM > βFM), while the contribution of FM to the BR and its annual percent change was higher than LM (|βFM| > |βLM|). Further analysis found that the associations of FM and LM with bone parameters were stronger in the underweight and normal weight participants (|βBMI1| > |βBMI2|). Overall, FM and LM had positive but differential effects on predicted hip bone strength, with a higher impact in the thinner participants.

Age and sex effects on the relationship between body composition and hip geometric structure in males and females from East China

The study finds bone mineral density is the principal determinant of hip geometry and lean mass is a better determinant than fat mass in Chinese. Moreover, the impact of fat on skeleton differs with age, with a negative effect in young people but a more positive effect in elderly.

PURPOSE

The aim of this study was to examine whether the correlation between body composition including bone mineral density (BMD), lean mass (LM) and fat mass (FM), and hip geometric structure change with aging in males and females from East China.

METHODS

It was a cross-section study. A total of 1168 healthy male and 1066 healthy females in Shanghai were divided into six groups based on their age and sex. All participants were evaluated by assessing the BMD of lumber spine and proximal hip, total LM, total FM, and geometric parameters of the hip such as the cross-sectional area (CSA), average cortical thickness (ACT), and the buckling ratio (BR) at the narrow neck (NN), the intertrochanter (IT), and the shaft (FS).

RESULTS

Among the three body composition, the correlation between hip BMD and hip geometric structure was strongest. LM showed significantly positive correlations with CSA. FM showed negative or little positive correlation with hip geometry in the young group. However, the degree of the contribution of FM to hip geometric structure became substantially positive with aging. Limb LM produced the largest positive contribution to CSA and ACT at all three regions in young males. However, in older males the trunk LM produced the largest positive contribution to CSA and ACT.

CONCLUSIONS

Among all body composition parameters, hip BMD showed the largest correlation with hip geometric structure, with LM showing the second largest. The impact of FM and LM on hip geometry changed with aging and with different distributions of lean mass and fat mass.

Fat Mass Is Positively Associated with Estimated Hip Bone Strength among Chinese Men Aged 50 Years and above with Low Levels of Lean Mass

This study investigated the relationships of fat mass (FM) and lean mass (LM) with estimated hip bone strength in Chinese men aged 50-80 years (median value: 62.0 years). A cross-sectional study including 889 men was conducted in Guangzhou, China. Body composition and hip bone parameters were generated by dual-energy X-ray absorptiometry (DXA). The relationships of the LM index (LMI) and the FM index (FMI) with bone phenotypes were detected by generalised additive models and multiple linear regression. The associations between the FMI and the bone variables in LMI tertiles were further analysed. The FMI possessed a linear relationship with greater estimated hip bone strength after adjustment for the potential confounders (p < 0.05). Linear relationships were also observed for the LMI with most bone phenotypes, except for the cross-sectional area (p < 0.05). The contribution of the LMI (4.0%-12.8%) was greater than that of the FMI (2.0%-5.7%). The associations between the FMI and bone phenotypes became weaker after controlling for LMI. Further analyses showed that estimated bone strength ascended with FMI in the lowest LMI tertile (p < 0.05), but not in the subgroups with a higher LMI. This study suggested that LM played a critical role in bone health in middle-aged and elderly Chinese men, and that the maintenance of adequate FM could help to promote bone acquisition in relatively thin men.

Bone Health Status in Indian Overweight/Obese Children

This cross-sectional study, to assess bone health in Indian overweight, obese children in comparison with healthy controls was conducted in 245 (126 girls) children and adolescents aged 6-17 y in Pune, India. It was found that total body bone mineral content, bone area and bone mineral density adjusted for Tanner stage and weight were significantly lower in obese children as compared to overweight children, which in turn, was significantly lower than normal weight children (p < 0.05). Thus, overweight and obesity is negatively related to bone health in children and adolescents. Interventions need to be planned to increase peak bone mass accrual in overweight and obese children to reduce future risk of fracture and osteoporosis.

The role of leptin in regulating bone metabolism

Leptin was initially best known for its role in energy homeostasis and regulation of energy expenditure. In the past few years we have realized that leptin also plays a major role in neuroendocrine regulation and bone metabolism. Here, we review the literature the indirect and direct pathways through which leptin acts to influence bone metabolism and discuss bone abnormalities related to leptin deficiency in both animal and human studies. The clinical utility of leptin in leptin deficient individuals and its potential to improve metabolic bone disease are also discussed. We are beginning to understand the critical role leptin plays in bone metabolism; future randomized studies are needed to fully assess the potential and risk-benefit of leptin's use in metabolic bone disease particularly in leptin deficient individuals.

Serum interferon gamma concentration is associated with bone mineral density in overweight boys

Childhood obesity has recently been linked to low-grade inflammation. Overweight children have slightly different processes of bone accumulation than normal weight children. The possible links between inflammation and bone accumulation have not previously been assessed in overweight children.

AIMS

An exploratory study to assess whether common inflammatory markers are associated with the development of obesity and bone accumulation in childhood.

METHODS

Thirteen different inflammatory markers in serum were measured in 38 boys with BMI >85th centile (overweight) and 38 boys with normal BMI (normal weight), aged 10-11 years. Total body (TB) and lumbar spine (LS) bone mineral density (BMD), bone mineral content (BMC) were measured by DXA. TB BMC for height, TB and LS bone mineral apparent density (BMAD) were calculated.

RESULTS

Overweight boys had higher mean TB and LS BMD, TB BMC and TB BMC for height, but lower mean TB BMAD (all p < 0.05) than normal weight boys. Serum interferon gamma (IFNγ) concentration was significantly (p < 0.05) correlated with TB BMD (r = 0.36), TB BMC (r = 0.38) and TB BMC for height (r = 0.53) in the broader overweight group (n = 38). In obese boys (BMI > 95 centile, n = 36) IFNγ was correlated with LS BMD (r = 0.38).

CONCLUSION

The positive correlation between serum INFγ concentration and BMD suggests that the inflammatory process, already involved in the early stage of obesity, may also affect bone accumulation. Further studies are needed to clarify the role of INFγ as a possible link between adipose tissue and bone health.

Lean mass predicts hip geometry and bone mineral density in chinese men and women and age comparisons of body composition

Previous studies have suggested that changes in hip geometry increase the risk of hip fracture. The aim of this study was to identify whether body composition were associated with hip geometry or bone mineral density (BMD) in a large sample of Chinese people. A total of 2072 subjects aged 20-79 yr (including 700 males and 1372 females) were selected. The following measurements were taken: lumbar spine (L1-4); proximal femur BMD; lean mass (LM); fat mass (FM); and hip geometric parameters, including hip axis length (HAL), cross-sectional moment of inertia (CSMI), cross-sectional area (CSA), neck-shaft angle, and femur strength index (SI) by dual-energy X-ray absorptiometry. FM and LM were positively correlated with HAL, CSMI, and CSA, and negatively correlated with SI in both men and women. Multiple regression analysis showed that leg LM contributions to HAL, CSMI, and CSA variance were 12.6-37.6%. Compared with FM, LM was generally more strongly related to hip geometry and BMD in young and old men and women. Body composition was a good predictor for hip geometry parameter variation and BMD variation.

Minireview: The link between fat and bone: does mass beget mass?

Osteoporosis is less common in individuals with high fat mass. This putative osteoprotection is likely an adaptive mechanism that allows obese individuals to better carry their increased body mass. Recent studies have focused on hormones that link fat to bone. Adipokines, such as leptin, modulate bone cells through both direct and indirect actions, whereas molecules activating peroxisome proliferator-activated receptor γ drive mesenchymal stem cell differentiation towards adipocytes away from the osteoblastic lineage. There is emerging evidence that bone-derived osteocalcin regulates insulin release and insulin sensitivity and, hence, might indirectly affect fat mass. Despite these molecular connections between fat and bone, animal and human studies call into question a primary role for body fat in determining bone mass. Mice devoid of fat do not have a skeletal phenotype, and in humans, the observed correlations between bone and body mass are not just due to adipose tissue. An improved understanding of the integrative physiology at the fat-bone interface should allow us develop therapies for both osteoporosis and obesity.