Determinants of bone mineral density, bone mineral content, and body composition in a cohort of healthy children: influence of sex, age, puberty, and physical activity

Abstract

Interventions directed to the recognition of abnormal bone mineral density, bone mineral content, and body composition in the pediatric age require the definition of factors influencing bone mass acquisition during growth. We have evaluated in a cross-sectional manner by dual-energy X-ray absorptiometry the impact of sex, age, puberty, and physical activity on total body areal bone mineral density, regional (lumbar and femoral) bone mineral densities, bone mineral content, and body composition (fat mass and lean mass) in a cohort of 359 healthy Italian children aged 3-14 years and investigated their specific contribution to bone mass accrual. Statistical multiple regression analysis was performed dividing the population in pre- and post-pubertal groups. Bone mineral density at the lumbar spine has resulted equally distributed in both sexes before puberty while has resulted higher at the femoral necks in males at whatever age. A significant effect on bone mass acquisition was exerted by male sex and lean mass. In the areas where the cortical bone is prevalent, males of the pre-pubertal group have presented the highest values; in the areas where the cancellous bone is prevalent, both sexes were equivalent until the age of 9 years, but after this age, females have presented higher increases, probably related to the inferior dimensional development of lumbar vertebrae. Conclusively, male sex and lean mass seem to represent independent predictors of bone mass accrual in the cortical bone of the examined children, while female sex and pubertal maturation are independent predictors of bone mass accrual in the trabecular bone.

Fatores que influenciam a massa óssea de crianças e adolescentes saudáveis mensurada pelo ultrassom quantitativo de falanges: revisão sistemática

“…BMD progressively increases between maturational stages in both genders in the different sites analyzed, such as the lumbar spine, femur, and whole body,19 , 20 , 27 - 29 corroborating the results of the QUS. That is, the data indicate that pubertal development is one of the factors that influence bone mass, and is positively associated with age, weight, height, and BMI, confirming that the development and increase of bone mass are directly associated with maturation and growth aspects.…”

“…In contrast, studies with DXA presented higher BMD values primarily in males, who had higher values at the femoral neck, full body, hip, and arm,17 - 20 whereas females presented higher BMD values for the lumbar spine 1820 After the end of the growth phase, with increasing age, the curve obtained by DXA is significantly higher for males, with higher BMD values after the age of 19 years 21…”

“…, 20 After the end of the growth phase, with increasing age, the curve obtained by DXA is significantly higher for males, with higher BMD values after the age of 19 years 21…”

Prevalence of Low Bone Mineral Density in Female Dancers

“…However, the anatomical sites measured and the sample characteristics of these studies differ, a fact that might have implications on BMD outcomes. BMD might be quite diverse in subjects with different training levels [63], ages [64] and ethnicities [65,66]. Indeed, ageing itself is considered to be a risk factor for low BMD and osteoporosis [67].…”

Associations between Bone Mineral Characteristics and Serum Levels of Ghrelin and Peptide YY in Overweight Adolescent Boys

“…However, in obese children an opposite picture has been seen, namely obese children have lower BMD when adjusting for their body size [10,11]. As the bone peak mass is the major determinant of bone strength in adulthood [12], it is particularly important to know the determinants of bone mass development in puberty and adolescence.…”