%0 Journal Article
%T Fat Modulates the Relationship between Sarcopenia and Physical Function in Nonobese Older Adults
%A Robin L. Marcus
%A Diana I. Brixner
%A Sameer Ghate
%A Paul LaStayo
%J Current Gerontology and Geriatrics Research
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/216185
%X It is intuitive to think that sarcopenia should be associated with declines in physical function though recent evidence questions this assertion. This study investigated the relationship between absolute and relative sarcopenia, with physical performance in 202 nonobese (mean BMI £¿kg/ht2) community-dwelling older (mean age = years) adults. While absolute sarcopenia (appendicular skeletal mass (ASM)/ht2) was either not associated, or weakly associated with physical performance, relative sarcopenia (ASM/kg) demonstrated moderate ( to , ) relationships with performance outcomes in both males and females. Knee extension strength ( ) and leg extension power ( ) were both related to absolute sarcopenia ( ) in females and not in males. Strength and power were associated with relative sarcopenia in both sexes (from to £¿ ). The ratio of lean mass to total body mass, that is, relative sarcopenia, is an important consideration relative to physical function in older adults even in the absence of obesity. Stratifying these individuals into equal tertiles of total body fat revealed a trend of diminished regression coefficients across each incrementally higher fat grouping for performance measures, providing further evidence that total body fat modulates the relationship between sarcopenia and physical function. 1. Introduction It seems intuitive that muscle structure (lean) and function (strength and power) are intricately linked to an older individual¡¯s level of physical function. Moreover, sarcopenia or the age-associated loss of lean tissue, along with increased whole-body and regional fat deposits, is a normal manifestation of old age [1]. There is substantial debate, however, as to whether sarcopenia can explain the age-diminished levels of physical function in older individuals. A recent review of the literature [1] highlights trends demonstrating that high whole-body fat mass (obesity) is more influential than low whole-body lean mass with respect to mobility and functional decline. The current consensus statement from the European Working Group on Sarcopenia in Older People [2], not specifically highlighting obesity per se, also reinforces the notion that lean body mass alone is not adequate to identify functional decline. Further, because absolute sarcopenia, defined as the ratio of appendicular skeletal mass (ASM) to an individual¡¯s height squared (ASM/ht2), does not demonstrate strong associations with physical function [3], it follows that lean body mass only weakly explains the lower levels of physical functioning in older adults. While this uncoupling
%U http://www.hindawi.com/journals/cggr/2012/216185/