Effects of hormone replacement therapy and high-impact physical exercise on skeletal muscle in post-menopausal women: a randomized placebo-controlled study

Abstract

An age-related decline in muscle performance is a known risk factor for falling, fracture and disability. In women, a clear deterioration is observed from early menopause. The effect of hormone replacement therapy (HRT) in preserving muscle performance is, however, unclear. This trial examined the effects of a 12-month HRT and high-impact physical exercise regimen on skeletal muscle in women in early menopause. A total of 80 women aged 50-57 years were assigned randomly to one of four groups: exercise (Ex), HRT, exercise+HRT (ExHRT) and control (Co). The exercise groups participated in a high-impact training programme. The administration of HRT (oestradiol/noretisterone acetate) or placebo was carried out double-blind. Knee extension torque and vertical jumping height were evaluated. Lean tissue cross-sectional area (LCSA) and the relative proportion of fat within the muscle compartment were measured for the quadriceps and lower leg muscles. The ExHRT group showed significant increases in knee extension torque (8.3%) and vertical jumping height (17.2%) when compared with the Co group (-7.2%). Vertical jumping height also increased after HRT alone (6.8%). The LCSA of the quadriceps was increased significantly in the HRT (6.3%) and ExHRT (7.1%) groups when compared with the Ex (2.2%) and Co (0.7%) groups. Lower leg LCSA was also increased in the ExHRT group (9.1%) when compared with the Ex (3.0%) and Co (4.1%) groups. In addition, the increase in the relative proportion of fat in the quadriceps in the Co group (16.6%) was significant compared with those in the HRT (4.9%) and ExHRT (-0.6%) groups. Thus, in post-menopausal women, muscle performance, muscle mass and muscle composition are improved by HRT. The beneficial effects of HRT combined with high-impact physical training may exceed those of HRT alone.

Power training and postmenopausal hormone therapy affect transcriptional control of specific co-regulated gene clusters in skeletal muscle

“…We found a significant 6% increase in muscle power with power training and 7% with HRT, while a 5% reduction was observed in control participants without any treatments (Sipilä et al 2001). Running speed increased by 4% both after HRT and power training and reduced by 2% in the controls (Taaffe et al 2005).…”

“…Strength, endurance, and power training have been found to exhibit beneficial albeit differential effects on aging musculature (e.g., Hoppeler et al 1985; Häkkinen et al 2000; Roth et al 2001; Timmons et al 2005; Porter 2006; Hazell et al 2007; Henwood et al 2008; Orsatti et al 2008). Progressive power training such as undertaken in the current study, is associated with enhanced quality of life, i.e., physical functioning and well-being (Katula et al 2008), neuromuscular functions involving rapid force production (Sipilä et al 2001; Taaffe et al 2005), and bone formation (Cheng et al 2002). Moreover, muscle power is essential for many daily tasks such as climbing stairs, rising from chair, and preventing a fall after a slip leading a number of recent studies (Hazell et al 2007; Paterson et al 2007; Katula et al 2008; Orr et al 2008) to conclude that strategies improving muscle power and composition are essential in order to prevent old age disability.…”

“…Indeed, several randomized controlled trials (RCT) have shown that hormone replacement therapy (HRT) increases muscle mass and improves neuromuscular performance when used in the beginning of the postmenopausal period (Skelton et al 1999; Sipilä et al 2001; Dobs et al 2002; Taaffe et al 2005). In addition, a co-twin study, in which monozygotic HRT users were compared to their non-using sisters, showed that long-term HRT treatment is associated with greater muscle power, higher walking speed, and decreased total body and thigh fat content (Ronkainen et al 2009).…”

“…In our yearlong RCT, the exercise and hormone replacement therapy-study (Ex/HRT), the effects of plyometric power training and HRT on bone as well as muscle structure and function in postmenopausal women were studied (Sipilä et al 2001; Cheng et al 2002; Taaffe et al 2005). We found a significant 6% increase in muscle power with power training and 7% with HRT, while a 5% reduction was observed in control participants without any treatments (Sipilä et al 2001).…”

“…Moreover, knee extensor muscle density increased significantly by both power training and HRT (Taaffe et al 2005) reflecting beneficial changes in muscle composition in favor of muscle tissue itself on the expense of adipose tissue (Goodpaster et al 2000). Knee extensor muscle cross-sectional area increased by 6% with HRT (Sipilä et al 2001). Our earlier microarray study investigating the effects of 1-year HRT use showed that the postmenopausal women without treatment have notable changes in their muscle transcriptome and that these changes were largely counteracted by the use of HRT (Pöllänen et al 2007).…”