Bone mineral content has stronger association with lean mass than fat mass among Indian urban adolescents

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.

Factors associated with bone health status of Malaysian pre-adolescent children in the PREBONE-Kids Study

Background

Modifiable lifestyle factors and body composition can affect the attainment of peak bone mass during childhood. This study performed a cross-sectional analysis of the determinants of bone health among pre-adolescent (N = 243) Malaysian children with habitually low calcium intakes and vitamin D status in Kuala Lumpur (PREBONE-Kids Study).

Methods

Body composition, bone mineral density (BMD), and bone mineral content (BMC) at the lumbar spine (LS) and total body (TB) were assessed using dual-energy X-ray absorptiometry (DXA). Calcium intake was assessed using 1-week diet history, MET (metabolic equivalent of task) score using cPAQ physical activity questionnaire, and serum 25(OH) vitamin D using LC-MS/MS.

Results

The mean calcium intake was 349 ± 180 mg/day and mean serum 25(OH)D level was 43.9 ± 14.5 nmol/L. In boys, lean mass (LM) was a significant predictor of LSBMC (β = 0.539, p < 0.001), LSBMD (β = 0.607, p < 0.001), TBBMC (β = 0.675, p < 0.001) and TBBMD (β = 0.481, p < 0.01). Height was a significant predictor of LSBMC (β = 0.346, p < 0.001) and TBBMC (β = 0.282, p < 0.001) while fat mass (FM) (β = 0.261, p = 0.034) and physical activity measured as MET scores (β = 0.163, p = 0.026) were significant predictors of TBBMD in boys. Among girls, LM was also a significant predictor of LSBMC (β = 0.620, p < 0.001), LSBMD (β = 0.700, p < 0.001), TBBMC (β = 0.542, p < 0.001) and TBBMD (β = 0.747, p < 0.001). Calcium intake was a significant predictor of LSBMC (β = 0.102, p = 0.034), TBBMC (β = 0.122, p < 0.001) and TBBMD (β = 0.196, p = 0.002) in girls.

Conclusions

LM was the major determinant of BMC and BMD among pre-adolescent Malaysian children alongside other modifiable lifestyle factors such as physical activity and calcium intake.

Associations of Weight-Adjusted Body Fat and Fat Distribution with Bone Mineral Density in Chinese Children Aged 6-10 Years

Although obesity is considered osteoprotective, the effects of body fat and fat distribution on bone tissue after adjusting for the effects of body weight remain uncertain. This study evaluated the relationships between fat mass, fat distribution, and bone mineral status beyond its weight-bearing effect. We recruited 466 children aged 6–10 years in China. Dual-energy X-ray absorptiometry was used to determine the bone mineral density (BMD) and bone mineral content (BMC) in the total body and total body less head (TBLH), as well as the fat mass (FM) and percentage fat mass (%FM) of the total and segmental body. Weight-adjusted measures of FM and %FM were derived using the residual method. After adjusting for the effects of covariates, we observed statistically significant, dose-dependent negative relationships between the TBLH·BMD/BMC and various weight-adjusted measures of body fat (p for trend: <0.001–0.038). For each standard deviation increment in the weight-adjusted total body, TBLH, trunk and limbs, the size-adjusted BMC decreased approximately 9.44, 9.28, 8.13, and 6.65 g in boys, respectively, and by approximately 13.74, 13.71, 7.84, and 12.95 g in girls, respectively. Significant inverse associations between FM accumulation in the total body and most body parts with the BMD/BMC were observed in both boys and girls after adjusting for weight and potential confounders.

Body Composition as a Mediator between Cardiorespiratory Fitness and Bone Mass during Growth

INTRODUCTION AND PURPOSE

To examine the effect of cardiorespiratory fitness (CRF) and muscle power output (MPO) on bone mass of prepubertal and pubertal children using lean mass (LM) and percentage of fat mass (%FM) as mediator variables. The hypothesis was that both LM and %FM would be independent mediators of the relationships during the sexual maturation period.

METHODS

We analyzed 200 children (88 boys and 112 girls [11.5 ± 2.0 yr]). Body composition was analyzed by bone densitometry, and indirect calorimetry and cycle ergometer were used to calculate V˙O2peak (mL·kg·min) and MPO (W) during an incremental exercise test. Sample was divided by pubertal status.

RESULTS

In the prepubertal group, LM and %FM acted independently as mediators in the relationship between bone mass and CRF or MPO (22%-25% for LM and 37%-50% for %FM, respectively). In pubertal children, LM acted as mediator at 37%.

CONCLUSIONS

Although the independent mediator role of LM and %FM in the associations between CRF or MPO and bone mass was present during the prepubertal stage, only LM remain its mediator role in these associations during the postpubertal period. Therefore, with growth and sexual maturation, the full effect of LM seems to increase, whereas the influence of %FM seems to disappear.

Birth Weight Could Influence Bone Mineral Contents of 10- to 18-Year-Old Korean Adolescents: Results from the Korea National Health and Nutrition Examination Survey (KNHANES) 2010

BACKGROUND

We investigate the relationship between birth weight (BW) and bone mineral content (BMC) in Korean adolescents.

METHODS

Data were obtained from the Korea National Health and Nutrition Examination Survey conducted in 2010. Baseline characteristics were compared according to age- and sex-specific BMC quartiles of total body less head (TBLH), lumbar spine (LS) and femur neck (FN) in 10- to 18-year-old adolescents (male = 474, female = 394).

RESULTS

BW showed a positive correlation with current weight-SDS (p = 0.006 in males, p = 0.008 in females). BW according to TBLH-BMC quartile groups (p for trend <0.003 in males, <0.0001 in females), LS-BMC quartile groups (p for trend <0.034 in males) and FN-BMC quartile groups (p for trend <0.008 in males, <0.020 in females) showed significant differences. The odds ratio (OR) of being in the highest BMC quartile, per 1-kg increase in BW, was significantly increased in TBLH-BMC (OR = 2.14 in males, OR = 3.26 in >16-year-old adolescents) and FN-BMC (OR = 2.62 in males, OR = 3.06 in >16-year-old adolescents) after adjusting for age, height, smoking, drinking, metabolic equivalent of task, and gestational age.

CONCLUSION

BW might be one of the determinant factors of BMC in Korean adolescents.