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Association between bone, body composition and strength in premenarcheal girls and postmenopausal women
L van Langendonck1, A L Claessens, R Lysens
1Department of Sport and Movement Sciences, Faculty of Physical Education and Physiotherapy, KU Leuven, Belgium. Vanlangendonck@flok.kuleuven.ac.be
Aim:
The study examined whether associations between bone, body composition and strength are age dependent.
Subjects And Methods:
Two age levels (premenarcheal girls and postmenopausal women on HRT) were studied in a 10-month follow-up. Bone, lean and fat mass were measured by dual-energy X-ray absorptiometry (DXA), and strength was measured using an isokinetic dynamometer.
Results:
In girls, significant correlations were found between mass (lean, fat and body mass), strength and most bone characteristics (r = 0.15-0.93). At the proximal femur changes in bone mineral density (BMD) were moderately related to changes in body composition. In the women, body mass and lean mass were significantly correlated with most bone characteristics (r = 0.34-0.82). Low to moderate correlations were observed between changes in bone and changes in body composition. After controlling for lean mass the relation between strength and bone was no longer significant.
Conclusions:
In premenarcheal girls, bone is partly determined by mass, with lean mass the most important predictor at the femoral sites. In postmenopausal women, lean mass is an important determinant of bone mineral content (BMC) and BMD, but changes in BMD are related to changes in fat. The relation between strength and BMD is mainly attributable to the relation between lean mass and BMD. The contributory effects of soft tissue to bone change over different life periods.
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