The relationship between visceral fat thickness and bone mineral density in sedentary obese children and adolescents

Dietary content and combined training, but not daily physical activity, are associated with 6-month bone mineral changes in adolescents with obesity: A Secondary analysis of the PAC-MAnO trial

PURPOSE

The present study aimed to explore the influence of diet and physical activity (PA) changes on bone mineral content (BMC) and density (BMD) alterations in adolescents with obesity undergoing a weight loss program.

METHODS

Six-month longitudinal data from 71 adolescents (aged 15.1 [± 1.6] years; 57.7% girls) with a BMI z-score of 3.03 (± 0.78), previously recruited for the PAC-MAnO trial, were analyzed using Generalized Estimation Equations for over time changes and linear regressions with BMC, BMD and BMD z-score as dependent variables, adjusting for confounders (including type of exercise- aerobic vs. combined).

RESULTS

Adjusting for confounders, changes in carbohydrate (CH) and protein content showed to positively and negatively predict BMD z-score variance, respectively (β = 0.44, 95%CI: 0.01, 0.04, p < .001); β = -0.57, 95%CI: -0.06, -0.03, p < .001), yet no associations were found between PA and bone-related parameters. Combined exercise showed better results on BMC compared to aerobic exercise (β = 0.09, 95%CI: 0.05 to 0.13, p < .001).

CONCLUSIONS

Increased CH content, instead of protein, may be associated with BMD improvements in adolescents with obesity. Type of exercise may moderate the impact of PA on bone health.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02941770. What is Known • Adolescents with obesity may be at a higher risk of osteopenia/osteoporosis • Obesity and inadequate diet and physical activity (PA) may have an adverse effect on bone metabolism What is New • Improvements in adiposity and muscle mass and increased diet carbohydrate content are associated with bone mineral density (BMD) improvements • Type of exercise (i.e., combined training vs. aerobic) may moderate the impact of PA on BMD, and calcium intake may mediate this impact.

Central obesity may affect bone development in adolescents: association between abdominal obesity index ABSI and adolescent bone mineral density

PURPOSE

Previous studies have suggested that obesity defined by body mass index(BMI) is a protective factor for bone mineral density(BMD), but have overlooked the potential influence of different types of obesity. This study aims to evaluate the correlation between abdominal obesity index A Body Shape Index(ABSI) and adolescent bone density, and analyze the relationship between abdominal obesity and bone metabolism.

METHODS

A total of 1557 adolescent participants were included in NHANES from 2007 to 2018. Calculate the ABSI using a specific formula that takes into account waist circumference and BMI. A weighted multiple linear regression model is used to evaluate the linear correlation between ABSI and BMD. Forest plots are used to analyze the correlations between subgroups, and cubic splines are limited to evaluate the nonlinear correlations and saturation effects between ABSI and BMD.

RESULTS

After adjusting for confounding factors, there was a significant linear correlation (P < 0.01) between ABSI and femoral BMD, both as a continuous variable and an ordered categorical variable. The restrictive cubic spline curve indicates a significant nonlinear correlation and saturation effect between adolescent ABSI and BMD.

CONCLUSION

Research has shown a significant negative correlation between ABSI and BMD at the four detection sites of the femur, and this correlation may vary slightly due to age, race, family income, and different detection sites. The research results indicate that compared to overall body weight, fat distribution and content may be more closely related to bone metabolism.

The multiple regulatory effects of white adipose tissue on bone homeostasis

White adipose tissue (WAT) is not only an energy storage reservoir that is critical in energy homeostasis but is also a highly metabolically active endocrine organ. WAT can secrete a variety of adipocytokines, including leptin (LEP), adiponectin (APN), resistin, visfatin, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and osteopontin (OPN). It can also synthesize and secrete exosomes, which enhance intercellular communication and participate in various physiological processes in the body. It can also synthesize and secrete exosomes to enhance intercellular communication and participate in a variety of physiological processes in the body. The skeleton is an important organ for protecting internal organs. It forms the scaffolding of the body and gives the body its basic form. It drives muscle contraction to produce movement under the regulation of the nervous system. It is also an important hematopoietic organ; and it is regulated by the cytokines secreted by WAT. As research related to the release of adipocytokines from WAT to affect the skeleton continues to progress, an inextricable link between bone lipid regulation has been identified. In this paper, we review the literature to summarize the structure, function and metabolism of WAT, elaborate the specific molecular mechanisms by which WAT-secreted hormones, cytokines and exosomes regulate skeletal cells, provide a theoretical basis for the in-depth study of WAT cross-organ regulation of bone, and provide new ideas for finding new adipose-secreted targeting factors for the treatment of skeletal diseases.

Association of total body fat and fat distribution with bone mineral density among children and adolescents aged 6-17 years from Guangzhou, China

This study aimed to assess the associations of total body fat and fat distribution with bone mineral density (BMD) among children and adolescents in this cross-sectional study. A total of 1032 boys and 897 girls aged 6-17 years were enrolled between May 2019 and June 2019 in Guangzhou, China. BMD, total body fat (fat mass index [FMI] and body fat percentage [BF%]), and fat distribution (trunk-to-limb and android-to-gynoid ratios) were measured by dual-energy X-ray absorptiometry. Inverse probability of treatment weighting regression was used to explore the association between fat and BMD. Traditional regression of covariate adjustment was applied as sensitivity analysis. Regression with inverse probability weighting suggested BF% and android-to-gynoid ratio were negatively associated with BMD in boys (β =  - 0.12 and - 0.16, respectively; P < 0.05). Android-to-gynoid ratio was also inversely associated with BMD in girls (β =  - 0.08, P < 0.05). When stratified by age, the negative associations were retained in boys aged 12-17 years (β =  - 0.23 and - 0.25, respectively; P < 0.001). But for girls, it showed a positive association of FMI with BMD in the 6-9 years group (β = 0.33, P < 0.001) and a negative association between the android-to-gynoid ratio and BMD in the 10-17 years group (β =  - 0.10, P < 0.05). Traditional regression supported the robustness of the results.  Conclusion: Total body fat is positively associated with BMD in younger girls but inversely associated in older boys. As for abdominal adipose, it is associated with lower BMD in both older boys and girls. What is Known: • The lean mass has been consistently positively associated with bone mineral density (BMD) among children and adolescents. However, the impact of fat mass on BMD remained controversial. • Beyond total body fat, site-specific fat mass, especially abdominal adiposity, might impede bone formation. What is New: • The associations of total body fat and fat distribution with BMD in children and adolescents were gender- and age-specific. • More attention should be paid to the abdominal fat accumulation to promote bone health in older children.

The relationship between obesity and bone mineral density in children and adolescents: analysis of the National Health and Nutrition Examination Survey

Childhood and puberty are important period for the skeleton grows. Fat mass, especially visceral adipose tissue, was negatively correlated with areal bone mineral density in children and adolescents. The present study suggests that fat mass, especially visceral adipose tissue, has a slightly negative association with bone development in children and adolescents.

PURPOSE

This study observed the relationship between fat mass and distribution, and areal bone mineral density (aBMD) in children and adolescents.

METHODS

A retrospective study was conducted on US children and adolescents aged 8-19 years. Whole body (less head) aBMD was evaluated. Height (Ht) adjusted Z-scores for aBMD were calculated.

RESULTS

After controlling for age, gender, race, and lean body mass index (LBMI) Z-score, there were significant negative associations between fat mass index (FMI) Z-score and aBMD Ht-Z-adjusted Z-score (β =  - 0.272, P < 0.001, R2 = 0.033). In the linear regression models with aBMD Ht-Z-adjusted Z-score as the dependent variable, the regression coefficients of android fat mass were - 0.241 (P < 0.05, R2 = 0.002), - 0.473 (P < 0.001, R2 = 0.036), and - 0.474 (P < 0.001, R2 = 0.038) for healthy weight, overweight, and obesity group, respectively. The regression coefficients of visceral adipose tissue (VAT) mass were - 0.218 (P > 0.05, R2 = 0.001), - 2.025 (P < 0.001, R2 = 0.044), and - 1.826 (P < 0.001, R2 = 0.039), and the regression coefficients of subcutaneous adipose tissue (SAT) mass were - 0.467 (P < 0.001, R2 = 0.004), - 0.339 (P < 0.01, R2 = 0.024), and - 0.347 (P < 0.001, R2 = 0.018) for healthy weight, overweight, and obesity group, respectively.

CONCLUSIONS

The present study suggests that fat mass has a slightly negative association with bone development in children and adolescents. Trunk fat accumulation, especially visceral adipose tissue, was correlated with the lower level of aBMD. This association was obvious in overweight and obese children.

High-fat diet causes undesirable bone regeneration by altering the bone marrow environment in rats

OBJECTIVE

Diet structure has changed greatly over the last few decades, and high-calorie diets have become an integral part of people's daily diet, as well as the important cause of obesity in society. Several organ systems, including the skeletal system, are seriously affected by high-fat-diets (HFD) in the world. There is, however, still a lack of knowledge about the effects of HFD on bone regeneration and the possible mechanisms involved. In this study, the difference in bone regeneration between rats under HFD and low-fat-diets (LFD) was evaluated by monitoring the process of bone regeneration in distraction osteogenesis (DO) model animals, as well as the possible mechanisms.

METHODS

A total of 40 Sprague Dawley (SD) rats (5 weeks old) were randomly divided into HFD group (n=20) and LFD group (n=20). Except for feeding methods, there were no differences between the two groups in terms of treatment conditions. All animals received the DO surgery eight weeks after starting to feed. After a delay of 5 days (latency phase), the active lengthening phase was performed for 10 days (0.25 mm/12 h), and the consolidation phase followed for 42 days. An observational study of bone included radioscopy (once a week), micro-computed tomography (CT), general morphology, biomechanics, histomorphometry, and immunohistochemistry.

RESULT

The results showed that HFD group had a higher body weight than LFD group after 8, 14, and 16 weeks of feeding. Furthermore, at the final observation, there were statistically significant differences between LFD group and HFD group in terms of total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) levels. Additionally, observations on bone regeneration showed a slower regeneration and a lower biomechanical strength in HFD group than LFD group, based on radiography, micro-CT, general morphology, biomechanics, histomorphometry, and immunohistochemistry.

CONCLUSION

In this study, HFD resulted in elevated blood lipids, increased adipose differentiation at the bone marrow level, and delayed bone regeneration. The pieces of evidence are beneficial to better understand the association between diet and bone regeneration and to adjust the diet optimally for fracture patients.

A cross-sectional study of the relationship between recreational sporting activity and calcaneal bone density in adolescents and young adults

OBJECTIVE

Childhood and adolescence are critical periods of bone development. Sporting activity is thought to impact peak bone mass acquisition, but most studies have used dual-energy X-ray absorptiometry (DXA) to assess bone health and reported associations between bone mass and elite sporting activity. The objective of this study was instead to assess the relationship between recreational sporting activity (RSA) and another bone assessment, calcaneal quantitative ultrasound (cQUS), in adolescents and young adults.

METHODS

We related recreational sporting activity, assessed through a lifestyle questionnaire, to heel ultrasound bone parameters in a cohort of New Zealand students aged 16-35 years. Complete datasets with data on all relevant confounders (body mass index (BMI), pubertal timing, smoking status, and alcohol consumption) were available for 452 participants. cQUS was performed using a Lunar Achilles EX II machine to obtain bone parameters, broadband ultrasound attenuation (BUA), and speed of sound (SOS); stiffness index (SI) was derived from these measures. All descriptive statistics and statistical analyses were carried out using SPSS Statistics for Macintosh, Version 23.0 (IBM Corp., Armonk, NY, USA). Results are presented as p-values and 95% CI.

RESULTS

Reported lifetime sport participation declined after an individual's mid-teens. Bone cQUS parameters (SI and BUA and T-score) were all positively associated with BMI, and current physical activity (SI, SOS, BUA, T-score, and Z-score) with SI and SOS measures most strongly associated with current high impact and past recreational sporting activity (all p < 0.05).

CONCLUSION

Calcaneal heel ultrasound bone parameters were associated with physical activity, with SI and SOS rather than BUA more strongly related to current and past recreational sporting activity in young New Zealand adults.

Bone mineral density and body composition in normal weight, overweight and obese children

BACKGROUND

There is a possibility that excess body fat affects bone mass gain and may compromise skeletal health in obese children. The purpose of the study was to identify the relationship between bone mineral density (BMD) and body composition in normal weight, overweight and obese children.

METHODS

This was a cross-sectional study of 6- to 11-year-old children who attended the hospital's outpatient clinic. They were apparently healthy and had no history of prematurity, low birth weight, or chronic diseases. Body mass index (BMI) was used to identify subjects as normal weight, overweight or obese. BMD and body composition were assessed by dual energy X-ray absorptiometry. The BMD values (total and lumbar spine) were compared between normal weight, overweight and obese children. Correlation coefficients were calculated, and multivariate models were performed.

RESULTS

Forty-nine children were included: 16 with normal weight, 15 that were overweight and 18 with obesity; the mean age was 8.4 ± 1.7 years. All the participants had a normal BMD (> - 2 SD). BMD was higher in obese children and had a positive correlation with total and trunk lean mass in the three study groups (p < 0.001). In obese children, an inverse correlation of lumbar spine BMD (Z score) with total and trunk fat mass (p < 0.05) was identified. In the multivariate models (with the whole group), the total lean mass was the only significant variable that explained BMD variability.

CONCLUSIONS

BMD in obese children was higher than that in normal weight children, which is explained by their greater lean mass and not by excess body fat. In obese children, a higher fat mass was related to a lower lumbar spine BMD. Lean mass had a direct correlation with BMD in the three study groups and was the most important predictor of BMD, reflecting the importance of strengthening the muscular system through performing physical activity and practicing a healthy lifestyle.

Health-Related Fitness in Slovak High School Students in Prešov Region

The purpose of this study was to examine the physical characteristics, body composition, and health-related fitness components in Slovak high school students. Data on body composition and health-related fitness were obtained from 848 students attending 14 high schools in the Prešov self-governing region. Health-related fitness levels were determined using the FITNESSGRAM test battery. Body composition was measured using a direct segmental multifrequency bioelectric impedance analyzer InBody 230. The results of the study showed gender differences in anthropometric measures, body composition parameters, and health-related fitness components. Analysis of variance among subgroups with different performance levels in particular tests showed an effect on anthropometric measures and body composition, especially on abdominal strength and endurance and upper body strength and endurance. Regarding gender differences, boys were found to be taller and heavier in all age groups. The BMI values showed a normal rate of physical development in all age groups and both genders. Overall, body composition was more optimal for boys than for girls. Girls were found to have a higher degree of abdominal fat and visceral adiposity. Boys were found to have higher levels of upper body strength and endurance and abdominal strength and endurance. The difference in flexibility level was statistically significant between 16 year-olds.

Relationship Between Muscle Strength, Body Composition and Bone Mineral Density in Adolescents

Adolescence is an important period for the acquisition of bone mass, which can be enhanced by several factors. This study aimed examine the relationships of handgrip strength, free-fat mass, and fat mass with bone mineral density in adolescents. 118 adolescents (60 girls), aged 10 to 14 years, participated in the study. Information on sex, age, handgrip strength, free-fat mass, fat mass and bone mineral density were collected. Multiple linear regression analyses were conducted to examine possible relationships between bone mineral density and handgrip strength, free-fat mass and fat mass. There was a relation between handgrip strength and free-fat mass with bone mineral density in both sexes. Fat mass was correlated with bone mineral density only in girls (r= 0.314, p< 0.014). The final models, adjusted for sexual maturation, included free-fat mass (girls - β= 0.419, p< 0.001; boys - β= 0.455; p< 0.001) and handgrip strength (girls - β= 0.358, p< 0.05; boys - β= 0.325; p< 0.05) and these variables together explained 51.8% and 62.9% of the variation of bone mineral density, in girls and boys, respectively. Handgrip strength and free-fat mass were positively associated with bone mineral density. A sex-specific difference indicated that higher levels of free-fat mass are of paramount importance for both sexes.

Association between Body Composition and Bone Mineral Density in Children and Adolescents: A Systematic Review and Meta-Analysis

Background: Bone mass acquisition during growth is a major determinant of the risk of developing osteoporosis later in life. Body composition is an anthropometric determinant of bone mineral density (BMD) and significantly influences its development during childhood and adolescence. Objective: This study aimed to systematically examine the association between body composition and bone mineral density in children and adolescents. Methods: Observational studies addressing this association were identified from PubMed (MEDLINE), Embase, Scopus and the Cochrane Library (up to January 2021). The study populations consisted of healthy children and adolescents. The DerSimonian and Laird method was used to compute pooled estimates of effect size and the respective 95% confidence intervals for upper limbs, femoral neck (FN), lumbar spine (LS) and total body, respectively. Subgroup analyses were further performed based on age, sex and ethnicity. Results: Thirty-one published studies were eligible for inclusion in this systematic review and meta-analysis, including three longitudinal studies. The combined population from all the studies amounted to 21,393 (11,205 males and 10,188 females). The pooled estimates of the correlation coefficients for lean mass (LM) and BMD ranged from 0.53 to 0.74 (p < 0.050), and the pooled regression coefficients ranged from 0.23 to 0.79 for FN, LS and total body (p < 0.050). For fat mass (FM), the pooled correlation coefficients ranged from 0.10 to 0.50 (p < 0.050) and the pooled regression coefficient was only significant for FN BMD with a weak strength (pooled β = 0.07, p < 0.050). The pooled regression coefficients for body fat percentage (BF%) were between −0.54 and −0.04 (p < 0.050). The subgroup analysis revealed a stronger association in Asians than in Caucasians for LM and in males compared to females for BF% (p < 0.050). Conclusions: This systematic review and meta-analysis supports a positive association between LM and BMD. BF% appears to have a deleterious effect on bone acquisition in children and adolescents.

Association of Body Compositions and Bone Mineral Density in Chinese Children and Adolescents: Compositional Data Analysis

The purpose of this study was to investigate the relationship between body compositions and bone mineral density (BMD) and the effect of composition substitution among Chinese children and adolescents without the influence of multicollinearity. A dual-energy X-ray absorptiometry scan was used to determine the amount of truncal fat (TF), nontruncal fat (NTF), fat-free mass (FFM), and BMD. The compositional data analysis and the compositional proportional substitution analysis were conducted to determine the effect of each part of body compositions on BMD and its substitution effects. Four hundred sixty-six (466) (boys: 51.9%) participants completed this cross-sectional study. For girls, in the overweight group, the relationship between TF and the BMD was positive (β = 2.943e - 01, p = 0.006) while the NTF showed the opposite trend (β = -2.358e - 01, p = 0.009). When 4% NTF or FFM was substituted by TF, the BMD increased by about 0.1 and 0.05 units (p < 0.05), respectively. For boys, the association between FFM and BMD was statistically positive (β = 4.091e - 02, p = 0.0001). There was a positive correlation between TF and BMD (β = 7.963e - 02, p = 0.036). But with the increase of BMI, this correlation shifted in the opposite direction. In conclusion, compared to TF and NTF, FFM had a better protective effect on BMD, especially for boys. The risk of NTF accumulation on BMD was greater than that of TF accumulation. Compared with girls, boys were more sensitive to the amount of TF.

Correlation Between Serum 25(OH)D and Abdominal Visceral Fat Area in Patients with Type 2 Diabetes Mellitus in the Context of different Bone Mass

OBJECTIVE

To investigate the correlation between serum levels of 25-hydroxy vitamin D [25(OH)D] and the visceral fat area of patients with type 2 diabetes mellitus (T2DM) in the context of different bone mass.

MATERIALS AND METHODS

A total of 180 patients with T2DM were randomly selected for bone mineral density (BMD) examination. According to the results, they were divided into three groups: T2DM normal bone group (group A); T2DM bone mass reduction group (group B); T2DM osteoporosis group (group C).

RESULT

Serum 25(OH)D levels in NC group, A group, B group and C group decreased in turn, and Visceral fat area (VFA) in group B and group C were significantly higher than those in group A and NC [(29.41±4.87) vs. (22.76±4.23) vs. (17.78±3.61) vs. (9.70±3.01), P<0.05], [(117.76±38.79), (125.08±37.90) vs. (89.79±26.51), (97.53±28.61), P<0.05]. Pearson correlation analysis showed that L1-L4 lumbar vertebrae bone density was positively correlated with 25(OH)D and VFA; left femoral neck bone density was positively correlated with 25(OH)D, and negatively correlated with VFA.

CONCLUSION

Serum 25(OH)D and VFA may be associated with the development of T2DM combined with OP.

Analysis of the Association between Fat Mass Distribution and Bone Mass in Chinese Male Adolescents at Different Stages of Puberty

Background: Bone mineral acquisition during adolescence is crucial for maximizing peak bone mass. Fat mass (FM) and bone mass are closely related. This study investigated the association of FM distribution with bone mass in Chinese male adolescents. Method: A total of 693 male adolescents aged 10–18 years were recruited from a secondary school in Jiangmen, China. Their bone mass and body composition were measured by quantitative ultrasound and bioelectrical impedance analysis, respectively. The associations of the measures of fat distribution with bone parameters, i.e., broadband ultrasound attenuation, speed of sound (SOS), and stiffness index (SI), were analyzed using multiple linear regression. Age, height, body mass index, stage of puberty, physical activity, sedentary behavior, dietary energy intake, and dietary calcium and vitamin D intake were adjusted in the model. Further subgroup analyses of prepubertal and pubertal participants were conducted. Results: The measures of fat distribution showed negative associations with SOS and SI in total subjects (p < 0.010). In prepubertal boys, the measures of fat distribution were only associated with SOS (β = −0.377 to −0.393, p < 0.050). In pubertal boys, the measures of fat distribution had associations with all bone parameters (β = −0.205 to −0.584, p < 0.050). The strongest association was between trunk FM and SOS (β = −0.584, p < 0.001). Conclusion: This study supported that the measures of fat distribution were negatively associated with bone parameters in Chinese male adolescents. Trunk FM had the strongest association with bone parameter. These associations appear to be stronger in pubertal boys than in prepubertal boys.

Sex differences in the relationship between body composition and biomarkers of bone and fat metabolism in obese boys and girls

Whether a body mass derived from extremes of body weight is beneficial to bone remains controversial. When fat accumulation reaches excessive levels and induces changes in hormonal factors and adipokines, it may affect bone accrual during growth. This study evaluated the relationships between body composition and key biomarkers in relation to bone and fat metabolism in obese Thai boys and girls. Subjects aged 12-14 years were grouped by body mass index (BMI) and percentage of body fat (%Fat). Body composition and heel bone Z-score and speed of sound (SOS) were assessed by bioelectrical impedance analysis and calcaneus bone densitometry, respectively. Serum osteocalcin (OC), adiponectin, leptin, insulin, and 25 hydroxyvitamin D (25(OH)D) were measured by ELISA. Their correlations were analyzed and compared between sexes. The results showed that the obese groups had no differences in mean BMIs and body composition, except that boys had more muscle mass than girls. Boys had lower serum OC and leptin levels than girls. Positive correlations of leptin with %Fat and FM were found in both sexes, while positive associations of %Fat with OC and insulin were found only in boys. Bone Z-score and SOS positively correlated with OC in boys but negatively correlated with 25(OH)D in girls. When classifying the obese group using %Fat ≥25, the positive correlations between %Fat and insulin and the negative associations between %Fat and adiponectin in girls were more pronounced. These results suggest that the associations of body fat and bone parameters with OC, adiponectin, 25(OH)D, and insulin were sex-specific, with greater clarity when %Fat was used instead of BMI to classify obesity.

Childhood adiposity, adult adiposity, and bone health

IMPORTANCE

Childhood and adolescence are critical periods for lifelong bone mineral accrual, but few studies have determined the impact of childhood adiposity on adult bone density.

OBJECTIVE

To determine the long-term impact of childhood adiposity on adult areal bone mineral density (aBMD) and the effect of adult adiposity on this relationship.

METHODS

We conducted a longitudinal study of 1156 adults (56.3% men), for whom skinfold thickness (SFT) had been measured during childhood (6-18 years) and fat mass percentage (FMP) and aBMD were measured during adulthood (29-43 years). Adult aBMD in the lumbar spine (LS), femoral neck (FN), arms, and legs was measured using dual-energy X-ray absorptiometry. The direct effect of childhood SFT and its indirect effect through adult FMP on adult aBMD were estimated using general linear regression and a causal steps approach.

RESULTS

Significant positive associations between childhood SFT and adult aBMD were found in the LS in men (β = 0.089, P = 0.044) and in all the skeletal sites in women. With respect to the adult fat-bone relationship, high adult FMP was associated with low aBMD in most of the sites in men, but with high FN aBMD in women (β = 0.144, P = 0.002). Moreover, suppressive effects of adult FMP on the associations between childhood SFT and adult aBMD in the LS (-34.8%) and legs (-67.1%) of men, and a positive effect on the FN aBMD in women (17.0%) were identified.

INTERPRETATION

Childhood adiposity appears to have a positive long-term effect on adult aBMD, which may be reduced by adiposity in adult men but reinforced by adiposity in adult women.

Bone Mineral Density of Femur and Lumbar and the Relation between Fat Mass and Lean Mass of Adolescents: Based on Korea National Health and Nutrition Examination Survey (KNHNES) from 2008 to 2011

It is most important to reach the maximum bone density in the childhood period to prevent developing osteoporosis; it is widely known that increased body weight has a positive correlation with bone density and that even though both the fat mass and lean mass have a significant impact on bone density, the latter mass has more importance for adults. Therefore, the study analyzed to identify the relationship between bone density and both fat mass and lean mass of Korean adolescents. Subjects were chosen among 21,303 people from the Korea National Health and Nutrition Examination Survey (KNHNES) between 2008 and 2011 that took a bone density checkup; as a result, 1454 teenagers aged between 12 and 18 were selected. Data analysis was performed in SAS ver. 9.4 (SAS Institute Inc., Cary, NC, USA) following the KNHNES and the weighted complex sample analysis was conducted; body fat mass and lean mass were divided into quintile groups, and to figure out the differences in bone density that were analyzed in six models adjusted by body weight (kg) and walking (yes/no), muscle strengthening exercises (yes/no), nutrition (intake of ca (g), and serum vitamin D (ng/mL)). Then, the generalized linear model (GLM) and trend test were conducted for each gender with a significance level of 0.05. The bone density differences of fat mass and lean mass were analyzed. The result of Model 6 considering all correction variables is as follows; in the case of male adolescents, the total femur and lumbar spine showed a significant difference (F = 13.120, p < 0.001; F = 12.900, p < 0.001) for fat mass, and the trend test showed that the figures significantly decreased (β = −0.030, p < 0.001; −0.035, p < 0.001). Meanwhile, for lean mass, the total femur and lumbar spine had a significant difference (F = 16.740, p < 0.001; F = 20.590, p < 0.001) too, but the trend test showed a significant increase (β = 0.054, p < 0.001; 0.057, p < 0.001). In the case of female adolescents, the lumbar spine (F = 3.600, p < 0.05) for lean mass showed a significant difference, and it also significantly rose in the trend test too (β = 0.020, p < 0.01). To sum up the results, for male adolescents, the bone density differences for fat mass (FM) and lean mass (LM) all had significant differences, but for female adolescents, only the lumbar spine for LM showed such a result. Meanwhile, both genders showed that LM had a more positive impact on bone density than FM.

Differences in areal bone mineral density between metabolically healthy and unhealthy overweight/obese children: the role of physical activity and cardiorespiratory fitness

OBJECTIVES

To examine whether areal bone mineral density (aBMD) differs between metabolically healthy (MHO) and unhealthy (MUO) overweight/obese children and to examine the role of moderate-to-vigorous physical activity (MVPA) and cardiorespiratory fitness (CRF) in this association.

METHODS

A cross-sectional study was developed in 188 overweight/obese children (10.4 ± 1.2 years) from the ActiveBrains and EFIGRO studies. Participants were classified as MHO or MUO based on Jolliffe and Janssen's metabolic syndrome cut-off points for triglycerides, glucose, high-density cholesterol and blood pressure. MVPA and CRF were assessed by accelerometry and the 20-m shuttle run test, respectively. Body composition was measured by dual-energy X-ray absorptiometry.

RESULTS

In model 1 (adjusted for sex, years from peak high velocity, stature and lean mass), MHO children had significantly higher aBMD in total body less head (Cohen's d effect size, ES = 0.34), trunk (ES = 0.43) and pelvis (ES = 0.33) than MUO children. These differences were attenuated once MVPA was added to model 1 (model 2), and most of them disappeared once CRF was added to the model 1 (model 3).

CONCLUSIONS

This novel research shows that MHO children have greater aBMD than their MUO peers. Furthermore, both MVPA and more importantly CRF seem to partially explain these findings.

Impact of changes in fat mass and lean soft tissue on bone mineral density accrual in adolescents engaged in different sports: ABCD Growth Study

Body composition can have a significant impact on bone mineral density (BMD) in pediatric patients and may cause bone disease. This study demonstrated that lean soft tissue (LST) seems to have a greater impact on BMD gain in the lower limbs of adolescents.

PURPOSE

To analyze the impact of changes in lean soft tissue (LST) and fat mass on areal bone mineral density (BMD) accrual in the lower limbs among adolescents engaged in sports with different weight-bearing levels.

METHODS

Longitudinal (12 months: measurements at two time points). Adolescents of both sexes (n = 191; 62 girls [32.5%] and 129 boys [67.5%]) were divided into three groups: control group (n = 65), swimming group (n = 25), and weight-bearing sports group (n = 100). Absolute changes in LST (kg) and fat mass (kg) were the independent variables, while BMD accrual (left and right legs) was the dependent variable. Linear regression was used to assess the relationship between dependent and independent variables in a multivariate model adjusted by sex, body weight, somatic maturation, serum osteocalcin, and baseline values of BMD of the lower limbs.

RESULTS

For the left leg, LST was positively related to areal BMD accrual in the control (β = 0.021 [95%CI: 0.001 to 0.042]) and weight-bearing sport groups (β = 0.051 [95%CI: 0.037 to 0.065]), but not among swimmers (β = 0.029 [95%CI: - 0.004 to 0.062]). For the right leg, LST was positively related to areal BMD accrual in the swimming group (β = 0.065 [95%CI: 0.031 to 0.100]) and weight-bearing sport groups (β = 0.048 [95%CI: 0.034 to 0.062]), but not in the control group (β = 0.014 [95%CI: - 0.002 to 0.030]). Fat mass was not significantly related to areal BMD in either leg.

CONCLUSIONS

Changes in LST were the most relevant determinant of BMD accrual in the lower limbs, mainly among adolescents engaged in sports.

External skeletal robustness and adiposity in adolescents of low socioeconomic status: A cross-sectional analysis of body composition

OBJECTIVES

External skeletal robustness has been decreasing in children, potentially due to a lack of physical activity and the increased prevalence of obesity. However, whether socioeconomic status (SES) influences external skeletal robustness in adolescents has not yet been examined.

METHODS

A cross-sectional study was performed to examine 370 Chilean adolescents (16.15 ± 1.01 years old) recruited from distinct educational establishments. Body fat percentage (BF%) was evaluated using Ellis' equations for Hispanic children. Obesity was defined as ≥25 BF% in males and ≥ 30 BF% in females. External skeletal robustness was obtained by measuring the humerus biepicondylar width and height (Frame-Index). SES was obtained through the ESOMAR survey.

RESULTS

Females exhibited significantly greater BF% and lower Frame-Index values than males (P < .001). Obese adolescents (by BF%) had greater Frame-Index values than non-obese adolescents (P < .001). Females of medium-high SES had significantly lower BF% and Frame-Index values than females of medium and medium-low SES. BF% had a positive correlation with Frame-Index values in all SES groups studied, except in males of medium-high SES. As SES decreased, the correlation increased in both sexes, but overall, the correlation was greater in females than males.

CONCLUSIONS

The results of this investigation suggest that obesity increases external skeletal robustness in adolescents. Additionally, lower SES corresponded to higher BF% and Frame-Index values. Therefore, modern conditions that influence the prevalence of obesity in adolescence could be affecting bone health in adolescents, primarily in females of medium-low SES.

Long-term childhood body mass index and adult bone mass are linked through concurrent body mass index and body composition

Body mass plays a crucial role in the bone growth and development, but few studies have examined the association of long-term cumulative impact and trajectory patterns of childhood body mass index (BMI) with adult bone mass, and the mediation effect of adult BMI and body composition on these associations. A total of 397 Chinese adults (54.4%) who had been examined for BMI 4-8 times during childhood (6-19 years) and bone mass in adulthood (29-37 years), were included for analysis. Adult bone mineral content (BMC), areal bone mineral density (aBMD) and body composition were assessed via dual-energy x-ray absorptiometry. Childhood BMI growth curves were constructed using a random-effects mixed model. The area under the curve (AUC) was calculated to represent the long-term impact of childhood BMI. At baseline, 24.4%, 66.2%, 7.6% and 1.8% of the participants were underweight, normal weight, overweight and obese, respectively. Quadratic curve parameters of childhood BMI differed significantly between groups of adult whole body (WB) BMC, lumbar spine (LS) aBMD and femoral neck (FN) aBMD, with low BMC/aBMD groups having lower childhood BMI than the normal groups. AUC of childhood BMI was significantly and positively related to adult WB BMC and aBMD at each site, irrespective of sex. Significant mediation effects of adult BMI were shown on the association of childhood BMI AUC with adult WB BMC in males (52.0%) and FN aBMD in both sexes (males: 65.4%; females: 64.3%). Additionally, mediation effect of fat mass index was only noted on the association of childhood BMI AUC with adult WB BMC (41.3%), with a positive total indirect effect estimated at 0.118. The adult lean mass index, by contrast, mediated the childhood BMI-adult BMC/aBMD association positively at all sites in males (71.5%~89.2%) and at WB BMC in females (45.0%). These findings suggest that the impact of body weight on adult bones originates from childhood, which is mediated by concurrent BMI and body composition.

Body composition and bone mineral density in childhood

BACKGROUND

Body mass compartments may have different directions of influence on bone accrual. Studies of children are limited by relatively small sample sizes and typically make strong assumptions of linear regression.

OBJECTIVE

To evaluate associations of overall body mass, components of overall body mass (fat-free and total fat), and components of total fat mass (truncal and non-truncal fat), measured via dual-energy X-ray absorptiometry (DXA) and anthropometry, with total body less head areal bone mineral density (aBMD) Z-score in mid-childhood.

METHODS

We performed a cross-sectional study among 876 Boston-area children who had DXA measures. We evaluated linearity of associations using generalized additive models.

RESULTS

Children were median 7.7 (range 6-10) years of age, and 61% were white. After adjustment for sociodemographics and other compartments of body mass, overall body mass, particularly the fat-free mass component, appeared to have a positive relationship with aBMD Z-score [e.g., 0.25 (95% CI: 0.23, 0.28) per 1-kg fat-free mass]. The relationship between truncal fat and aBMD Z-score appeared non-linear, with a negative association only in children with levels of fat mass in the upper 15th percentile [-0.17 (95% CI: -0.26, -0.07) aBMD Z-score per 1-kg truncal fat mass], while non-truncal fat mass was not associated with aBMD Z-score.

CONCLUSIONS

Our analyses suggest that central adiposity is associated with lower aBMD Z-score only in children with the highest levels of abdominal fat. This finding raises the possibility of a threshold above which central adipose tissue becomes more metabolically active and thereby adversely impacts bone.

The Impact of Childhood Obesity on Skeletal Health and Development

Increased risk of fracture identified in obese children has led to a focus on the relationship between fat, bone, and the impact of obesity during skeletal development. Early studies have suggested that despite increased fracture risk, obese children have a higher bone mass. However, body size corrections applied to account for wide variations in size between children led to the finding that obese children have a lower total body and regional bone mass relative to their body size. Advances in skeletal imaging have shifted the focus from quantity of bone in obese children to evaluating the changes in bone microarchitecture that result in a change in bone quality and strength. The findings suggest that bone strength in the appendicular skeleton does not appropriately adapt to an increase in body size which results in a mismatch between bone strength and force from falls. Recent evidence points to differing influences of fat compartments on skeletal development-visceral fat may have a negative impact on bone which may be related to the associated adverse metabolic environment, while marrow adipose tissue may have an independent effect on trabecular bone development in obese children. The role of brown fat has received recent attention, demonstrating differences in the influence on bone mass between white and brown adipose tissues. Obesity results in a shift in growth and pubertal hormones as well as influences bone development through the altered release of adipokines. The change in the hormonal milieu provides an important insight into the skeletal changes observed in childhood obesity.

Analysis of lifestyle and bone mineralization in a population of Spanish young adults

OBJECTIVE

To analyze the environmental factors (nutritional status, levels of physical activity and nutritional habits) and their possible association with bone mass in a population of young adults.

METHODS

The study population consisted of 200 subjects (117 women and 83 men) aged between 18 and 25 years (mean age 20.4 years ±2.2 years). Body composition parameters were measured by an electronic balance (TANITA BC-418MA), nutritional habits were estimated by 72-h dietary recall, level of physical activity was assessed by the International Physical Activity Questionnaire (IPAQ) and bone mass was measured by ultrasonography at the calcaneus.

RESULTS

There were significant differences in bone mass values ​​according to gender (p= 0.013). Despite the fact that 70% of the subjects had a body mass index (BMI) within the normal range, 20% had overweight or obesity. 49% of the individuals had a moderate level of physical activity, although women had lower levels of physical activity than men (17.9% vs 8.4%). Most diets among young adults were hyperprotic, hyperlipidic and low-carbohydrates, with low-calcium and fiber intakes and high-phosphorus. Analysis of bone mass according to BMI showed higher values ​​as the weight category rises, with significant differences in women. Higher values ​​of bone mass were shown as the level of physical activity was higher, showing significant differences in males.

CONCLUSION

Our results show that BMI and level of physical activity are significantly associated with bone health in a population of young adults, suggesting the relevance of promoting healthy lifestyles as a strategy for the early prevention of osteoporosis.

Obesity in Pediatric Trauma

Obese children with high-energy injuries present with more severe injuries, more extremity injuries, and higher Injury Severity Scores. They are at increased risk for complications, prolonged ventilation, and ICU stay and have increased mortality. Obesity is associated with altered bone mass accrual and higher fracture rates. Obese patients have a higher risk of loss of reduction of forearm fractures, more severe supracondylar fractures, and a higher likelihood of lateral condyle fractures. Obese patients are more likely to have complications with femur fractures and have higher rates of foot and ankle fracture.

High-Fat Diet-Induced Obesity Promotes Expansion of Bone Marrow Adipose Tissue and Impairs Skeletal Stem Cell Functions in Mice

Obesity represents a risk factor for development of insulin resistance and type 2 diabetes. In addition, it has been associated with increased adipocyte formation in the bone marrow (BM) along with increased risk for bone fragility fractures. However, little is known on the cellular mechanisms that link obesity, BM adiposity, and bone fragility. Thus, in an obesity intervention study in C57BL/6J mice fed with a high-fat diet (HFD) for 12 weeks, we investigated the molecular and cellular phenotype of bone marrow adipose tissue (BMAT), BM progenitor cells, and BM microenvironment in comparison to peripheral adipose tissue (AT). HFD decreased trabecular bone mass by 29%, cortical thickness by 5%, and increased BM adiposity by 184%. In contrast to peripheral AT, BMAT did not exhibit pro-inflammatory phenotype. BM progenitor cells isolated from HFD mice exhibited decreased mRNA levels of inflammatory genes (Tnfα, IL1β, Lcn2) and did not manifest an insulin resistant phenotype evidenced by normal levels of pAKT after insulin stimulation as well as normal levels of insulin signaling genes. In addition, BM progenitor cells manifested enhanced adipocyte differentiation in HFD condition. Thus, our data demonstrate that BMAT expansion in response to HFD exerts a deleterious effect on the skeleton. Continuous recruitment of progenitor cells to adipogenesis leads to progenitor cell exhaustion, decreased recruitment to osteoblastic cells, and decreased bone formation. In addition, the absence of insulin resistance and inflammation in the BM suggest that BMAT buffers extra energy in the form of triglycerides and thus plays a role in whole-body energy homeostasis. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.

Does Visceral or Subcutaneous Fat Influence Peripheral Cortical Bone Strength During Adolescence? A Longitudinal Study

This study evaluated the longitudinal relationships among visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and peripheral bone strength during adolescence. Fat and lean mass, VAT and SAT area, and android/gynoid (A/G) ratio were estimated with DXA. Our main outcome was strength-strain index (SSI), an indicator of peripheral bone strength estimated by pQCT at the radius and tibia. Sex-specific analyses evaluated the longitudinal bone-fat relationship from ages 11 to 19 years with linear mixed models using biological age as the time variable and adjusted for limb length and lean mass in 182 girls and 167 boys. Variables were standardized (mean = 0, SD = 1) prior to model fitting and results shown are parameter estimates ± SE. Fat mass and SAT were positively associated with SSI (radius: 0.07 ± 0.02, p = 0.003 and 0.05 ± 0.02, 0.041, respectively; tibia: 0.09 ± 0.02, p < 0.001 and 0.08 ± 0.02, p < 0.001, respectively) prior to, but not following adjustment for lean mass in girls. In contrast, fat mass and SAT were negatively associated with radial SSI, both before and after adjustment for lean mass in boys (fat mass: -0.05 ± 0.01, p = 0.001; SAT: -0.04 ± 0.01, p = 0.004). In full models, negative associations were limited to VAT in girls and included radial (-0.06 ± 0.02, p = 0.001) and tibial SSI (-0.04 ± 0.02, p = 0.033). For boys, there were no significant associations present between VAT and SSI at the radius or tibia. In analyses limited to obese participants, an A/G ratio was not significantly associated with SSI in girls, but was negatively associated with radial SSI regardless of adjustment for lean mass in boys (-0.06 ± 0.02, p = 0.018). These results that show a negative relationship between peripheral bone strength and VAT in girls, but greater total and central adiposity in boys, suggest these factors play a role in adequate acquisition of bone strength during adolescence. © 2017 American Society for Bone and Mineral Research.

Abdominal obesity adversely affects bone mass in children

AIM

To determine the effect of childhood obesity and insulin resistance on bone health.

METHODS

We conducted a cross sectional study in pubertal adolescents and young adults 13-20 years old who were either overweight/obese or normal weight. Participants were Tanner 3 or above for pubertal stage, and had fasting blood work done to measure glucose, insulin, C-reactive protein and lipid levels. Homeostatic model of insulin resistance (HOMA-IR) was calculated using the formula (Fasting Blood Glucose *Insulin/405). Body composition and bone mineral density were measured using dual energy X-ray absorptiometry (DXA; Hologic QDR 4500, Waltham, MA, United Kingdom).

RESULTS

Percent trunk fat was associated inversely with whole body bone mineral content (BMC), whereas HOMA-IR was associated positively with whole body BMC.

CONCLUSION

Our results suggest that abdominal adiposity may have an adverse effect on whole body bone parameters and that this effect is not mediated by insulin resistance.

Influence of adipose tissue mass on bone mass in an overweight or obese population: systematic review and meta-analysis

Context

The scientific literature shows conflicting evidence about the relationship between adiposity and bone mass in overweight and obese populations. The aim of this review was to quantify the correlation between adipose mass (absolute and relative) and bone mineral density (BMD) in overweight and obese populations. Three databases were searched electronically. In addition, reference lists of relevant articles were screened. A total of 16 studies, comprising 2587 participants and 75 correlation coefficients were selected for inclusion in the review. Data were extracted from each study using a standardized form. Multilevel modeling indicated opposing relationships between BMD and adiposity: absolute adiposity correlated positively, and relative adiposity negatively, with BMD. Sex and age were the primary moderators of these relationships. Strong evidence supported a negative relationship between relative adipose mass and BMD in men (R = -0.37; 95%CI, -0.57 to -0.12) and in those aged less than 25 years (R = -0.28; 95%CI, -0.45 to -0.08). To prevent bone loss in overweight and obese populations, nutrition- and exercise-based interventions that focus on a controlled reduction of adipose mass with concomitant preservation of lean mass are recommended. : PROSPERO no. CRD42015024313.

The Association of Fat and Lean Tissue With Whole Body and Spine Bone Mineral Density Is Modified by HIV Status and Sex in Children and Youth

BACKGROUND

HIV-infected (HIV-pos) male children/youth showed lower bone mineral density at sexual maturity than HIV-uninfected (HIV-neg) females. It is not known whether complications of HIV disease, including abnormal body fat distribution, contribute to lower bone accrual in male HIV-pos adolescents.

METHODS

In a cross-sectional study, we evaluated the relationship between body composition (fat and lean mass) and bone mass in HIV-pos and HIV-neg children/youth and determined if it is modified by HIV status and sex. We used generalized estimating equations to simultaneously model the effect of fat/lean mass on multiple bone outcomes, including total body bone mineral density and bone mineral content and spine bone mineral density. We evaluated effect modification by HIV and sex.

RESULTS

The analysis cohort consisted of 143 HIV-neg and 236 HIV-pos, of whom 55% were black non-Hispanic and 53% were male. Ages ranged from 7 to < 25 years. Half of the children/youth were at Tanner stage 1 and 20% at Tanner 5. Fat mass was more strongly positively correlated with bone mass in HIV-neg than HIV-pos children/youth and these relationships were more evident for total body bone than spine outcomes. Within HIV strata, fat mass and bone were more correlated in female than male children/youth. The relationship between lean mass and bone varied by sex, but not by HIV status.

CONCLUSIONS

HIV disease diminishes the positive relationship of greater fat mass on bone mass in children/youth. Disruptions in body fat distribution, which are common in HIV disease, may have an impact on bone accretion during pubertal development.

The impact of the Standard American Diet in rats: Effects on behavior, physiology and recovery from inflammatory injury

BACKGROUND AND AIMS

Obesity is a significant health concern in the Western world and the presence of comorbid conditions suggests an interaction. The overlapping distributions of chronic pain populations and obesity suggests that an interaction may exist. Poor quality diet (high carbohydrates, saturated fats, omega-6 polyunsaturated fatty acids) can lead to increased adiposity which can activate immune cells independent of the activating effect of the diet components themselves. This dual action can contribute to chronic inflammation that may alter susceptibility to chronic pain and prolong recovery from injury. However, traditional examinations of diet focus on high-fat diets that often contain a single source of fat, that is not reflective of an American diet. Thus, we examined the impact of a novel human-relevant (high-carbohydrate) American diet on measures of pain and inflammation in rats, as well as the effect on recovery and immune cell activation.

METHODS

We developed a novel, human-relevant Standard American Diet (SAD) to better model the kilocalorie levels and nutrient sources in an American population. Male and female rats were fed the SAD over the course of 20 weeks prior to persistent inflammatory pain induction with Complete Freund's Adjuvant (CFA). Mechanical and thermal sensitivity were measured weekly. Spontaneous pain, open field locomotion and blood glucose levels were measured during diet consumption. Body composition was assessed at 20 weeks. Following full recovery from CFA-induced hypersensitivity, blood was analyzed for inflammatory mediators and spinal cords were immunohistochemically processed for microglial markers.

RESULTS

Chronic consumption of the SAD increased fat mass, decreased lean mass and reduce bone mineral density. SAD-fed rats had increased leptin levels and pro-inflammatory cytokines in peripheral blood serum. Following CFA administration, mechanical sensitivity was assessed and recovery was delayed significantly in SAD-fed animals. Sex differences in the impact of the SAD were also observed. The SAD increased body weight and common T-cell related inflammatory mediators in female, but not male, animals. In males, the SAD had a greater effect on bone mineral density and body composition. Long-term consumption of the SAD resulted in elevated microglial staining in the dorsal horn of the spinal cord, but no sex differences were observed.

CONCLUSIONS

We demonstrate the negative effects of an American diet on physiology, behavior and recovery from injury. SAD consumption elevated pro-inflammatory mediators and increased microglial activation in the spinal cord. While there were sex differences in weight gain and inflammation, both sexes showed prolonged recovery from injury.

IMPLICATIONS

These data suggest that poor quality diet may increase susceptibility to chronic pain due to persistent peripheral and central immune system activation. Furthermore, consumption of a diet that is high in carbohydrates and omega-6 polyunsaturated fatty acid is likely to lead to protracted recovery following trauma or surgical procedures. These data suggest that recovery of a number of patients eating a poor quality diet may be expedited with a change in diet to one that is healthier.

The relationship between adiposity and bone density in U.S. children and adolescents

Objective

In adults, obesity has been associated with several health outcomes including increased bone density. Our objective was to evaluate the association between percent body fat and fat mass with bone mineral density (BMD) in a nationally representative population of children and adolescents.

Study design

A total of 8,348 participants 8–18 years of age from the National Health and Nutrition Examination Survey (NHANES) 1999–2006 had whole body DXA scans performed. We conducted linear regressions to examine the relationship between percent body fat and fat mass with outcome variables of total body, pelvic and lumbar spine areal BMD (aBMD), controlling for lean body mass and assessing for gender and race/ethnicity interactions.

Results

We found evidence of gender and race/ethnicity interactions with percent body fat and total fat mass for the different BMD areas. Generally, there were decreases in total body aBMD (p<0.001) and lumbar spine aBMD (p<0.001) with increasing percent body fat and total fat mass, with less consistent patterns for pelvic aBMD.

Conclusion

Our findings of regional differences in the relationship of adiposity to aBMD in children and adolescents with significant interactions by gender and race/ethnicity emphasizes the need for further investigations to understand the impact of adiposity on bone health outcomes.

Do metabolic syndrome and its components have an impact on bone mineral density in adolescents?

In recent years, there has been growing concern about the occurrence of metabolic syndrome (MetS) at an early age and its effects on bone mass in adolescents. Adolescence is considered a critical period for bone mass gain. Impaired bone acquisition during this phase can lead to “suboptimal” peak bone mass and increase the risk of osteopenia/osteoporosis and fractures in old age. The objective of this review was to perform a critical analysis of articles that specifically focus on this age group, evaluating the influence of MetS and its components on bone mineral density in adolescents. A possible relationship between this syndrome and bone mass has been demonstrated, but the number of studies addressing this topic in adolescents is small. Despite the scarcity of evidence, the results of those studies show that Metabolic Syndrome is negatively correlated with bone mass and also that some components of MetS are negatively correlated with bone mineral density in adolescents. However, the associations between MetS and bone mass development need to be further explored in the age group corresponding to adolescence. Further good-quality studies are necessary to complement the understanding of this relationship.

Sleep Quality and Body Composition Variations in Obese Male Adults after 14 Weeks of Yoga Intervention: A Randomized Controlled Trial

Background:

Obesity is a big challenge all over the world. It is associated with many noncommunicable diseases. Yoga known to be add-on treatment may be effective for obesity control.

Aim:

To assess the effect of integrated approach of yoga therapy (IAYT) for body composition and quality of sleep in adult obese male.

Subjects and Methods:

A randomized controlled trial was conducted for 14 weeks on obese male of urban setting. Eighty individuals were randomly divided into two groups, i.e., yoga group (n = 40; age; 40.03 ± 8.74 years, body mass index [BMI] 28.7 ± 2.35 kg/m²) and control group (age; 42.20 ± 12.06 years, BMI 27.70 ± 2.05 kg/m²). The IAYT was imparted to yoga group for 1½ hour for 5 days in a week for 14 weeks. The control group continued their regular activities. The body composition by InBody R20 and sleep quality by Pittsburgh Sleep Quality Index (PSQI) were assessed. Statistical analysis was done for within and between groups using SPSS version 21. The correlation analysis was done on the difference in pre-post values.

Results:

The results showed that weight (P = 0.004), BMI (P = 0.008), bone mass (P = 0.017), obesity degree (P = 0.005), and mineral mass (P = 0.046) were improved in yoga group and no change in control group (P > 0.05). The global score of PSQI improved (P = 0.017) in yoga group alone.

Conclusion:

The results indicate the beneficial effects of IAYT on body composition and sleep quality in obese males. The yoga practice may reduce obesity with the improvement in quality of life.

Vaspin regulates the osteogenic differentiation of MC3T3-E1 through the PI3K-Akt/miR-34c loop

Vaspin (visceral adipose tissue-derived serine protease inhibitor) is a newly discovered adipokine that widely participates in diabetes mellitus, polycystic ovarian syndrome and other disorders of metabolism. However, the effect of vaspin on the regulation of osteogenesis and the mechanism responsible are still unclear. Here, we found that vaspin can attenuate the osteogenic differentiation of the preosteoblast cell line MC3T3-E1 in a dose-dependent way; also, during this process, the expression of miRNA-34c (miR-34c) was significantly increased. Down-regulation of the expression of miR-34c in MC3T3-E1 diminished the osteogenic inhibitory effect of vaspin, while the up-regulation of miR-34c increased this effect through its target gene Runx2. Meanwhile, we found that vaspin could also activate the PI3K-Akt signalling pathway. Blocking the PI3K-Akt signalling pathway with specific inhibitors could decrease the osteogenic inhibitory effect of vaspin as well as the expression level of miR-34c. Furthermore, knock-down of miR-34c could promote the activation of Akt, which was probably realised by targeting c-met expression. Thus, PI3K-Akt and miR-34c constituted a modulation loop and controlled the expression of each other. Taken together, our study showed that vaspin could inhibit the osteogenic differentiation in vitro, and the PI3K-Akt/miR-34c loop might be the underlying mechanism.

The relation between intra- and interpersonal factors and food consumption level among Iranian adolescent girls

Background:

Poor nutrition habits in adolescent girls endanger their health and are followed by serious systemic diseases in adulthood and negative effects on their reproductive health. To design health promotion programs, understanding of the intra- and interpersonal associated factors with treatment is essential, and this was the aim of this study.

Materials and Methods:

This cross-sectional study was conducted on 193 adolescent girls of age 11-15 years. Random cluster selection was used for sample selection. Food group consumption pattern was assessed by food frequency questionnaire. Also, perceived susceptibility/severity and nutritional attitude as intrapersonal factors and social support as interpersonal factor were assessed. The relationship between food group consumption level and nutritional attitude and perceived treat (susceptibility/severity) as intrapersonal factors and perceived social support as interpersonal factor were assessed by linear multiple regression and analysis of variance (ANOVA).

Results:

Results showed that the level of sweetmeat food consumption was related to perceived social support (P = 0.03) and nutritional attitude (P = 0.01) negatively. In addition, an inverse and significant association was found between the level of junk food intake and informational perceived social support (P = 0.004). The association between the level of fast food intake and the perceived parental social support for preparation of healthy food was negatively significant (P = 0.03). Breakfast consumption was related to nutritional attitude (P = 0.03), social support (P = 0.03), and perceived severity (P = 0.045).

Conclusions:

Results revealed that perceived social support and nutritional attitude are the important and related factors in dietary intake among girls, and promotion of social support and modification of nutritional attitude may lead to healthy nutritional behaviors among them.

Bone-adiposity cross-talk: implications for pediatric obesity. A narrative review of literature

The rising prevalence of overweight and obesity among pediatric populations has become a major global concern. The objective of this review is to demonstrate potential interactions between the products released by fat tissue and the hormonal production of bone tissue in obese children and adolescents. Advancing the understanding of the complex interactions between adipocyte and osteocyte activities may contribute to the mechanistic understanding of the body's responses to weight loss during adolescence. This knowledge could also reveal any side effects encountered with these interventions. Currently, the concept of bone-adiposity crosstalk has not been fully elucidated, and the mechanisms remain controversial. Understanding the local interactions between the released products by fat tissue and hormones produced in bone tissue requires further investigations.

Bone Density, Osteocalcin and Deoxypyridinoline for Early Detection of Osteoporosis in Obese Children

AIM

This study aimed at comparing between bone density using DEXA, serum osteocalcin and urinary DPD in obese and non obese prepubertal children.

METHODS

After taking the consent of eighty children they were subjected to: full examination, anthropometric measurements, blood samples were withdrawn to determine serum osteocalcin, Ca, Ph, alkaline phosphatase, and urinary DPD. Bone densities, body composition of the whole body were examined using DEXA. Data were analyzed using SPSS.

RESULTS

All anthropometric variables showed significant increase in obese children except for height in comparison to control group. Total mass, lean + BMC, lean, fat, area, BMC, BMD and Z score of the whole body were significantly increased in obese children. Serum calcium showed significant increase while alkaline phosphatase was significantly decreased in obese children. DPD showed no significant difference between obese and non obese children. Significant negative correlation was found between ca, lean, lean + BMC and total mass. Serum alkaline phosphatase showed also a significant negative correlation with (lean + BMC and total mass). Serum osteocalcin showed negative significant correlation with area, BMC, BMD, lean and Z score.

CONCLUSION

Obese children showed significant increase in anthropometric and DEXA parameters, increase in serum calcium and significant decrease in serum alkaline phosphatase. Osteocalcin was negatively correlated with most of DEXA results.

Relative Importance of Lean and Fat Mass on Bone Mineral Density in Iranian Children and Adolescents

BACKGROUND

Body weight is made up of lean and fat mass and both are involved in growth and development. Impression of these two components in bone density accrual has been controversial.

OBJECTIVES

The aim of this study was to evaluate the relationship between fat and lean mass and bone density in Iranian children and adolescents.

PATIENTS AND METHODS

A cross-sectional study was performed on 472 subjects (235 girls, 237 boys) aged 9-18 years old in Fars Province. The participants' weight, height, waist circumference, stage of puberty, and level of physical activity were recorded. Bone Mineral Content (BMC), Bone Mineral Density (BMD), total body fat and lean mass were measured using dual-energy X-ray absorptiometry.

RESULTS

Results showed that 12.2% of boys and 12.3% of girls were overweight and 5.5% of boys and 4.7% of girls were obese. Obese individuals had greater total body BMD (0.96 ± 0.11) than normal-weight ones (0.86 ± 0.11) (P < 0.001). We found the greatest correlation between total body BMD and total body lean mass (R = 0.78. P < 0.001) and the least correlation with total body fat percentage (R = 0.03, P = 0.44). Total lean mass in more active boys was 38.1 ± 10.9 and in less active boys was 32.3 ± 11.0 (P < 0.001). The results of multiple regression analysis showed that age and total body lean mass were independent factors of BMD in growing children and adolescents.

CONCLUSIONS

These findings suggest that lean mass was the most important predictor of BMD in both genders. Physical activity appears to positively impact on lean mass and needs to be considered in physical education and health-enhancing programs in Iranian school children.

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.

The Relationship between Body Fat Percent and Bone Mineral Density in Korean Adolescents: The Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-1), 2010

BACKGROUND

The relationships of total and regional body fat percent with bone mineral density (BMD) in Korean adolescents were examined using the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-1), 2010.

METHODS

Body fat percent at whole body (WBFP), trunk (TBFP), and extremities (both upper and lower extremities fat mass/body weight, EBFP), ratio of trunk fat mass to extremities fat mass (TEFR), and BMD at whole body, total femur, and lumbar spine were measured by dual energy X-ray absorptiometry in a population-based sample of 433 boys and 362 girls, aged 12 to 18 years. The analyses were conducted using linear regression analysis with complex sampling design.

RESULTS

After adjusting for confounders such as age, height, weight, serum 25-(OH) vitamin D concentration, energy intake, calcium intake, physical activity, and menarche status for girls, WBFP, TBFP, and EBFP were inversely associated with whole and regional BMD in both sexes (P < 0.05). TEFR was positively associated with whole and regional BMD in boys after adjusting for confounders, while it was negatively associated in girls (P < 0.05). However, the associations were non-significant when bone mass-free lean mass was adjusted instead of bodyweight except for a positive association between TEFR and BMD in boys.

CONCLUSION

In Korean adolescents, total and regional body fat percent is not independently associated with BMD after adjusting for bone mass-free lean mass but higher fat in trunk as compared to extremities may be protective for BMD in boys.