Muscle strength and bone in healthy women: Effect of age and gonadal status

Objective: The aim of this work was to examine the effects of age and menopause on muscle strength and on the muscle-bone interaction. Design: One hundred ninety-four healthy women (mean age 49.8 ± 12.6 SD years) were assessed. Maximal Voluntary Contraction (MVC, Newton, N) by Hand Grip Dynamometer, bone mineral density at one third of the radius (R-BMD) by dual-energy X-ray absorptiometry (DXA) and phalangeal ultrasound by the DBM Sonic 1200 device were evaluated at the upper dominant limb. Ultrasonometric parameters considered were Amplitude-Dependent Speed of Sound (ADSoS) and Ultrasound Bone Profile Index (UBPI). Results: MVC significantly decreased with age (r2=-0.12, p<0.005). For each level of age, fertile women had a greater MVC compared to postmenopausal women (r2=0.015, p<0.005). In the whole sample, a statistically significant correlation between MVC and R-BMD (r=0.354, p<0.001) and between MVC and ADSoS (r=0.294) and UBPI (r=0.311)(p<0.001 for both) were observed. Conclusions: We conclude that age and menopausal status significantly contributed to the reduction of muscle strength. The decline of muscular strength significantly correlated with quantitative and qualitative bone features.