High muscle mass may be linked to healthier bone development in children, according to research published in the journal Bone.
Researchers also found the relationship between lean muscle and bone development was stronger in girls than boys, despite the children’s ages, ruling out puberty as a consideration. No relationship was observed between fat mass and bone development in prepubescent children, according to researchers.
“Bone strength and size is important because they are significant factors in long-term osteoporosis and fracture risk,” Rebecca J. Moon, MD, of the medical research council (MRC) life course epidemiology unit at University of Southampton, United Kingdom, said in a press release. “A 10% increase in peak bone mass will delay the onset of osteoporosis by 13 years. These findings point to the importance of early childhood physical activity to optimize muscle and bone growth.”
Moon, Cyrus Cooper, OBE, MA, DM, FRCP, FFPH, FMedSci, director of the MRC life course epidemiology unit at University of Southampton, and colleagues at other institutions analyzed data from 200 children (48.5% boys) enrolled in the Southampton Women’s Survey, a population-based, mother-offspring cohort. Researchers measured fat mass and lean mass at birth and then again at age 6 to 7 years using DXA. At age 6 to 7 years, researchers assessed bone mineral density, shape and size of the tibia, and body composition. Researchers adjusted fat mass, lean mass and bone parameters for both age and sex, standardizing to create within-cohort z scores.
In univariate analysis at age 6 to 7 years, changes in lean mass or fat mass were positively associated with tibial size and whole-body bone mineral content. Only a change in lean mass, however, was positively associated with trabecular volumetric BMD (beta = 0.26; 95% CI, 0.13-0.4).
Lean mass, once adjusted for fat mass, was positively associated with the tibial total cross-sectional area at both the 4% (P < .001) and 38% sites (P < .001), cortical cross-sectional area (P < .001) and trabecular volumetric BMD (P < .001).
Neither lean mass nor fat mass affected cortical volumetric BMD, according to researchers.
Body changes resulting from puberty, however, could alter the future bone-fat relationship in both boys and girls seen in this study, according to researchers.
“Future longitudinal evaluation of our cohort through pubertal development, currently ongoing, might also reveal differing associations with age and sexual maturation,” the researchers wrote. – by Regina Schaffer
Disclosure: Moon and Cooper report no relevant financial disclosures. See the full study for a list of the other authors’ relevant financial disclosures.