The relationship between lean mass, muscle strength and physical ability in independent healthy elderly women from the community

The association between muscle mass, strength and physical performance has been established in the elderly with co-morbidities. In this study, lean and fat mass, bone mineral density, knee extension and flexion strength and physical ability tests in healthy independent elderly women were investigated. Main determinants of lean mass, strength and physical ability were determined searching for predictors of healthy aging. A total of 100 healthy women aged a parts per thousand yen 65 years considered independent and active were invited. Bone mass and body composition were assessed by DXA. The strength of the lower limb was assessed by isokinetic dynamometry, and physical ability was measured by: Timed Up and Go (TUG), Berg Balance Test (BBT) and Dynamic Gait Index (DGI). Women were on average 70.8 +/- 4.92 years old, had BMI of 27.38 +/- 5.11 kg/m2 and fat mass of 26.96 +/- 9.62 kg or 40.65 +/- 8.06%. Total lean mass and appendicular lean mass (ALM) were 35.38 +/- 4.83 kg and 15.32 +/- 2.26 kg, respectively, while relative skeletal mass index (RSMI) was 6.51 +/- 0.77 kg/m2. Age did not correlate significantly with ALM. Age and ALM were the main determinants of the strength of the lower limb (p < 0.001) while age and strength of the lower limb were significantly associated with the performance on the physical tests (p < 0.001). Age has a negative impact on the strength and the physical performance in independent healthy women without co-morbidities. Physical ability tests are positively influenced by the strength of the lower limb. These relationships suggest that muscle strength should be the parameter to be prioritized when preparing for healthy aging.