The Journals of Gerontology Series A: Biological Sciences and Medical Sciences Advance Access published online on November 3, 2009
The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, doi:10.1093/gerona/glp159
Dynapenic-Obesity and Physical Function in Older Adults
1 School of Kinesiology and Health Studies
2 Department of Community Health Epidemiology, Queen's University, Kingston, Ontario, Canada
Address correspondence to Danielle R. Bouchard, PhD, School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada K7L 3N6. Email: danielle.bouchard{at}queensu.ca
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Abstract |
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Background: Dynapenia (low muscle strength) and obesity are associated with an impaired physical function. It was hypothesized that older individuals with both conditions (dynapenic-obesity) would have a more impaired physical function than individuals with dynapenia or obesity alone.
Methods: This cross-sectional study included 2,039 men and women aged 55 years and older from the 1999–2002 National Health and Nutrition Examination Survey. Fat mass was measured by dual-energy x-ray absorptiometry and leg strength by dynamometer. Based on fat mass and leg strength tertiles, four independent groups were identified: non-dynapenic and non-obese, obese alone, dynapenic alone, and dynapenic-obese. An objective physical function measure was obtained from a 20-foot walking speed test, whereas subjective physical function measures were obtained from five self-reported questions.
Results: Within both sexes, the dynapenic-obese group had a slower walking speed than the non-dynapenic and non-obese and obese-alone groups (p 
.01) but not the dynapenic-alone group. Similarly, with the exception of the dynapenic-alone group in men, the global subjective score was lower in the dynapenic-obese group than in the non-dynapenic and non-obese and obese-alone groups (p .01). By comparison to the dynapenic-obese group, the adjusted odds ratios (95% confidence interval) for walking disability were 0.21 (0.12–0.35) in the non-dynapenic and non-obese, 0.34 (0.20–0.56) in the obese-alone, and 0.54 (0.33–0.89) in the dynapenic-obese groups. The corresponding odds ratios for a disability based on the global subjective score were 0.20 (0.09–0.42), 0.60 (0.30–1.21), and 0.41 (0.19–0.87).
Conclusion: Dynapenic-obesity was associated with a poorer physical function than obesity alone and in most cases with dynapenia alone.
Keywords Fat mass; Muscle strength; Physical performance
Received: June 10, 2009; Accepted: September 24, 2009