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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #282666

Title: Muscle strength and BMI as predictors of major mobility disability in the lifestyle interventions and independence for elders pilot (LIFE-P)

Author
item MARSH, ANTHONY P. - Wake Forest University
item REJESKI, W. JACK - Wake Forest University
item ESPELAND, MARK A. - Wake Forest School Of Medicine
item MILLER, MICHAEL E. - Wake Forest School Of Medicine
item CHURCH, TIMOTHY S. - Pennington Biomedical Research Center
item FIELDING, ROGER A. - Jean Mayer Human Nutrition Research Center On Aging At Tufts University
item GILL, THOMAS M. - Yale School Of Medicine
item GURALNIK, JACK M. - University Of Maryland
item NEWMAN, ANNE B. - University Of Pittsburgh
item PAHOR, MARCO - University Of Florida

Submitted to: Journal of Gerontology Medical Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/7/2011
Publication Date: 12/1/2011
Citation: Marsh, A., Rejeski, W., Espeland, M., Miller, M., Church, T., Fielding, R., Gill, T., Guralnik, J., Newman, A., Pahor, M. 2011. Muscle strength and BMI as predictors of major mobility disability in the lifestyle interventions and independence for elders pilot (LIFE-P). Journal of Gerontology Medical Science. 66A(12):1376-1383 PMID: 21975090.

Interpretive Summary: Muscle weakness and obesity are two significant threats to mobility facing older adults. This study was conducted on sedentary functionally limited participants. These participants completed a 400 meter walk test, then either participated in a physical activity or health education courses and reassessed for major mobility disability every 6 months for up to 18 months. We evaluated whether baseline grip strength and body mass index (BMI) predicted failure to complete the 400 meter test in 15 minutes or less (Major mobility disability). The data highlighted the importance of muscle weakness, low BMI, and obesity as risk factors for major mobility disability in older adults.

Technical Abstract: Muscle weakness and obesity are two significant threats to mobility facing the increasing number of older adults. To date, there are no studies that have examined the association of strength and body mass index (BMI) on event rates on a widely used performance measure of major mobility disability. This study was a secondary analysis of a randomized controlled trial in which sedentary functionally limited participants (70–89 years, Short Physical Performance Battery less than or equal to 9) who were able to complete a 400-m walk test at baseline were randomized to a physical activity or health education intervention and reassessed for major mobility dis¬ability every 6 months for up to 18 months. We evaluated whether baseline grip strength and BMI predicted failure to complete the 400-m walk test in 15 minutes or less (major mobility disability). Among N = 406 participants with baseline measures, lower grip strength was associated with an increased risk for developing major mobility disability, with and without covariate adjustment (p less than .01): The hazard ratio (95% confidence interval) for the lowest versus high sex-specific quartile of grip strength was 6.11 (2.24–16.66). We observed a U-shaped relationship between baseline BMI and the risk of developing major mobility disability, such that the risk for participants with a BMI of 25–29 kg/m2 was approximately half that of participants with BMI less than 25 or 30 kg/m2 or more (p = .04 in fully adjusted analyses). Our data highlight the importance of muscle weakness, low BMI, and obesity as risk factors for major mobility disability in older adults. Being overweight may be protective