Dual-energy X-ray absorptiometry (DXA) is an attractive method for evaluating sarcopenia, age-related loss of skeletal muscle mass and function, using appendicular lean tissue (aLT) mass for criteria of diagnosis, alt...Dual-energy X-ray absorptiometry (DXA) is an attractive method for evaluating sarcopenia, age-related loss of skeletal muscle mass and function, using appendicular lean tissue (aLT) mass for criteria of diagnosis, although minimal radiation is exposed. Skeletal muscle (SM) mass can be estimated by using ultrasound-measured muscle thickness (MTH). However, the association between these two methods is unclear. To examine the relationship between DXA-derived aLT mass and total body SM mass estimated by ultrasound, thirty-six healthy adults (18 men and 18 women) aged 19 - 65 years participated in this study. Ultrasound-measured muscle thickness was used to estimate the total SM mass. DXA was used to estimate whole body and regional body composition, and aLT mass was considered equivalent to the sum of lean tissue in both the right and left arms and legs. Total SM mass (26.3 ± 4.4 kg for men and 15.7 ± 2.6 kg for women) estimated by ultrasound was similar to DXA-estimated aLT mass (24.5 ± 3.8 kg for men and 15.7 ± 2.7 kg for women). There was a strong correlation between DXA-measured aLT mass and total SM mass estimated by ultrasound in men (r = 0.927, n = 18) and women (r = 0.931, n = 18) as well as overall sample (r = 0.975, n = 36). The ratio of total SM mass to aLT mass was 1.07 for men and 1.00 for women. These results suggest that DXA-derived aLT mass can be accurately predicted from ultrasound estimated total SM mass, although the predicted value may underestimate in men (approximately 7% at the group level).展开更多
Knowledge of measured energy expenditure(EE)during walking and running is important for exercise pre-scription.Further,research on the EE comparison and EE predicted equation during walking or running among different ...Knowledge of measured energy expenditure(EE)during walking and running is important for exercise pre-scription.Further,research on the EE comparison and EE predicted equation during walking or running among different ethnicities is limited.The purpose of the current study was to compare EE to walk or run 1 mile in Caucasian,African American and Asian adults and to develop a regression equation to predict EE to walk or run 1 mile.Two hundred and twenty-four participants were included(71 Caucasians,68 African Americans and 85 Asians)with 3 groups(normal weight walking,overweight walking and running).EE was measured via indirect calorimetry.Analysis of variance was used to compare EE across groups.Multiple regression analysis was employed for EE prediction,and the prediction equation was cross-validated.A significant EE difference was found between walking and running among three ethnicities.The prediction equation was:EE=0.978 Body Weight-4.571 Gender(male=1;female=2)+3.524 Ethnicities(Caucasians=1,African Americans=2,Asians=3)+32.447(standard error of estimate=12.5 kcal·mile^(-1)).The equation was valid through cross-validation,so it is recommended to apply for calculating EE during walking or running 1 mile among Cauca-sians,African Americans and Asians.展开更多
文摘Dual-energy X-ray absorptiometry (DXA) is an attractive method for evaluating sarcopenia, age-related loss of skeletal muscle mass and function, using appendicular lean tissue (aLT) mass for criteria of diagnosis, although minimal radiation is exposed. Skeletal muscle (SM) mass can be estimated by using ultrasound-measured muscle thickness (MTH). However, the association between these two methods is unclear. To examine the relationship between DXA-derived aLT mass and total body SM mass estimated by ultrasound, thirty-six healthy adults (18 men and 18 women) aged 19 - 65 years participated in this study. Ultrasound-measured muscle thickness was used to estimate the total SM mass. DXA was used to estimate whole body and regional body composition, and aLT mass was considered equivalent to the sum of lean tissue in both the right and left arms and legs. Total SM mass (26.3 ± 4.4 kg for men and 15.7 ± 2.6 kg for women) estimated by ultrasound was similar to DXA-estimated aLT mass (24.5 ± 3.8 kg for men and 15.7 ± 2.7 kg for women). There was a strong correlation between DXA-measured aLT mass and total SM mass estimated by ultrasound in men (r = 0.927, n = 18) and women (r = 0.931, n = 18) as well as overall sample (r = 0.975, n = 36). The ratio of total SM mass to aLT mass was 1.07 for men and 1.00 for women. These results suggest that DXA-derived aLT mass can be accurately predicted from ultrasound estimated total SM mass, although the predicted value may underestimate in men (approximately 7% at the group level).
文摘Knowledge of measured energy expenditure(EE)during walking and running is important for exercise pre-scription.Further,research on the EE comparison and EE predicted equation during walking or running among different ethnicities is limited.The purpose of the current study was to compare EE to walk or run 1 mile in Caucasian,African American and Asian adults and to develop a regression equation to predict EE to walk or run 1 mile.Two hundred and twenty-four participants were included(71 Caucasians,68 African Americans and 85 Asians)with 3 groups(normal weight walking,overweight walking and running).EE was measured via indirect calorimetry.Analysis of variance was used to compare EE across groups.Multiple regression analysis was employed for EE prediction,and the prediction equation was cross-validated.A significant EE difference was found between walking and running among three ethnicities.The prediction equation was:EE=0.978 Body Weight-4.571 Gender(male=1;female=2)+3.524 Ethnicities(Caucasians=1,African Americans=2,Asians=3)+32.447(standard error of estimate=12.5 kcal·mile^(-1)).The equation was valid through cross-validation,so it is recommended to apply for calculating EE during walking or running 1 mile among Cauca-sians,African Americans and Asians.
