BACKGROUND: Nutritional evaluation of elderly people is of great importance. Two-component methods for body composition assessment, such as anthropometry and bioelectrical impedance (BIA), are widely used in clinical practice, but their fundamental assumptions may be invalid in older people. Dual-energy X-ray absorptiometry (DXA) is a relatively new method for reliable and direct measurements of body mass in its three basic components: total body bone mineral content (TBBMC), mineral free lean tissue mass (LTM), and fat. In this study, percent body fat (%BF) estimates from anthropometry and BIA in men of various ages were compared with corresponding measurements by DXA. METHODS: Body fat percentage was estimated in 67 men aged 20-95 by anthropometric measurements (skinfold thickness, body mass index, or BMI), BIA, and DXA. Age-specific equations were used for anthropometry and BIA. Limits of agreement were calculated between DXA and the other methods. RESULTS: The equations based on BMI and BIA systematically overestimated %BF with respect to %BF measured by DXA in people of all ages. Intermethod difference between DXA and skinfold thicknesses was less marked, but in over-80-year-olds %BF predicted by skinfold measurements underestimated %BF measured by DXA. Interindividual and age-related variation in TBBMC and in fat-free mass mineralization could partly explain the intermethod differences found between DXA and the other methods. CONCLUSIONS: Because of practical constraints, anthropometry and BIA are often the only available options for body composition assessment in clinical routine; therefore, further research on the validity and improvement of these methods in older people is indicated.
BACKGROUND: Nutritional evaluation of elderly people is of great importance. Two-component methods for body composition assessment, such as anthropometry and bioelectrical impedance (BIA), are widely used in clinical practice, but their fundamental assumptions may be invalid in older people. Dual-energy X-ray absorptiometry (DXA) is a relatively new method for reliable and direct measurements of body mass in its three basic components: total body bone mineral content (TBBMC), mineral free lean tissue mass (LTM), and fat. In this study, percent body fat (%BF) estimates from anthropometry and BIA in men of various ages were compared with corresponding measurements by DXA. METHODS: Body fat percentage was estimated in 67 men aged 20-95 by anthropometric measurements (skinfold thickness, body mass index, or BMI), BIA, and DXA. Age-specific equations were used for anthropometry and BIA. Limits of agreement were calculated between DXA and the other methods. RESULTS: The equations based on BMI and BIA systematically overestimated %BF with respect to %BF measured by DXA in people of all ages. Intermethod difference between DXA and skinfold thicknesses was less marked, but in over-80-year-olds %BF predicted by skinfold measurements underestimated %BF measured by DXA. Interindividual and age-related variation in TBBMC and in fat-free mass mineralization could partly explain the intermethod differences found between DXA and the other methods. CONCLUSIONS: Because of practical constraints, anthropometry and BIA are often the only available options for body composition assessment in clinical routine; therefore, further research on the validity and improvement of these methods in older people is indicated.
Authors: K H C Vilaça; F J A Paula; E Ferriolli; N K C Lima; J S Marchini; J C Moriguti Journal: J Nutr Health Aging Date: 2011-06 Impact factor: 4.075
Authors: Pranav S Garimella; Misti L Paudel; Kristine E Ensrud; Lynn M Marshall; Brent C Taylor; Howard A Fink Journal: J Am Geriatr Soc Date: 2013-01 Impact factor: 5.562
Authors: Anthony J Donato; Grant D Henson; Corey R Hart; Gwenael Layec; Joel D Trinity; R Colton Bramwell; Ryley A Enz; R Garrett Morgan; Kelly D Reihl; Sugata Hazra; Ashley E Walker; Russell S Richardson; Lisa A Lesniewski Journal: J Physiol Date: 2014-07-18 Impact factor: 5.182