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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #167321
Title: SKELETAL MUSCLE CUTPOINTS ASSOCIATED WITH ELEVATED DISABILITY RISK IN OLDER MEN AND WOMEN

Author
item JANSSEN, IAN - TUFTS/HNRCA, QUEENS UNIV
item BAUMGARTNER, RICHARD - UNIVERSITY OF NEW MEXICO
item ROSS, ROBERT - QUEENS UNIVERSITY
item ROSENBERG, IRWIN - TUFTS/HNRCA
item ROUBENOFF, RONENN - TUFTS/HNRCA

Submitted to: American Journal of Epidemiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2003
Publication Date: 2/15/2004
Citation: Janssen, I., Baumgartner, R.N., Ross, R., Rosenberg, I.H., Roubenoff, R. 2004. Skeletal muscle cutpoints associated with elevated disability risk in older men and women. American Journal of Epidemiology. 159:413-421.

Interpretive Summary: The age-related decrease in muscle mass (sarcopenia) is associated with a reduction in strength and increase in disability. However, the specific skeletal muscle threshold or cutpoint below which disability risk increases is unknown. The purpose of this study was to identify specific skeletal muscle quantities that are associated with an increased likelihood of disability in older persons. Our findings demonstrate that the likelihood of disability was increased to a high degree when skeletal muscle (normalized for height) values were

Technical Abstract: The age-related decrease in muscle mass (sarcopenia) is associated with a reduction in strength and increase in disability, however, the specific skeletal muscle threshold or cutpoint below which disability risk increases in unknown. To determine skeletal muscle cutpoints for identifying elevated disability risk in older adults, a nationally representative cross-sectional survey was done using data from the Third National Health and Nutrition Examination Survey (NHANES III) with 4,449 NHANES III participants aged 60 and above. Disability was assessed using standard questions. Bioelectrical impedance analysis was used to estimate whole-body muscle mass, which was normalized for height (muscle mass in kg/height in m**2) and termed the skeletal muscle index (SMI). Receiver-Operating-Characteristics were used to develop SMI cutpoints associated with high and low likelihood ratios for disability. Odds ratios for disability were compared in subjects falling above and below the SMI cutpoints. SMI cutpoints of 5.76-6.75 kg/m**2 and /= 6.76 kg/m**2) , the adjusted odds ratios (95% confidence intervals) for disability were 1.46 (1.00-2.15, P = 0.051) and 3.15 (1.84-3.40, P = 0.0001) for women with SMI values within the moderately increased risk and high-risk categories, respectively. By comparison to men with low-risk SMI values (>/= 10.76 kg/m**2), the adjusted odds ratios for disability were 3.48 (1.84-6.57, P < 0.001) and 4.60 (2.07-10.20, P < 0.001) for men with SMI values within the moderately increased risk and high-risk categories, respectively. This study presents skeletal muscle cutpoints for increased disability risk in older men and women. These cutpoints can be used by clinicians, health care practitioners, and researchers to determine which of their older patients are at increased risk for disability consequent to low muscle mass.