Association of body composition and muscle function with hip geometry and BMD in premenopausal women.
BACKGROUND
Muscle mass and function are related to bone mineral density (BMD) but associations with bone geometry and BMD at differently loaded hip regions are less well-known.


OBJECTIVE
To examine associations of muscle strength, maximal impact forces and body composition with hip bone density and geometry.


METHODS
In 88 sedentary, premenopausal women (32.6 +/- 8.5 years), fat-free mass (FFM), isometric knee extension strength (IKES), and peak landing ground reaction force (GRF) were measured. BMD at the proximal femur and sub-regions, section modulus (Z), and cross-sectional area (CSA) were estimated using dual X-ray absorptiometry.


RESULTS
BMD at hip sites was significantly associated with body mass, IKES, GRF and FFM (r = 0.31-0.50) whilst Z and CSA were correlated with FFM (r = 0.67 and 0.62, respectively). In multivariate models, variables explaining most variance were body mass for lower neck and shaft BMD (25% and 17%, respectively), IKES for upper neck BMD (21%), GRF for trochanter (19%) and total hip BMD (18%) and FFM for femoral neck Z, CSA and BMD (54%, 38% and 20%, respectively).


CONCLUSIONS
BMD at superolateral hip sites was most strongly related to muscle function and maximal impact forces, BMD at inferiomedial hip sites to body mass, and hip geometry to FFM.
Bailey
Christine A
CA
Department of Medicine, The University of Melbourne, Western Hospital Footscray, Victoria 3011, Australia.
Brooke-Wavell
Katherine
K
D000293:Adolescent; D000328:Adult; D001823:Body Composition / Q000502:physiology*; D015519:Bone Density / Q000502:physiology*; D005260:Female; D006615:Hip / Q000033:anatomy & histology* / Q000502:physiology*; D006801:Humans; D007717:Knee / Q000502:physiology; D016014:Linear Models; D009132:Muscles / Q000502:physiology*; D017697:Premenopause / Q000502:physiology*; D055815:Young Adult