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United States Department of Agriculture

Agricultural Research Service

Research Project: Nutrition, Sarcopenia, Physical Activity, and Skeletal Muscle Function in the Elderly

Location: Jean Mayer Human Nutrition Research Center On Aging

Title: Effects of a one year physical activity program on serum C Terminal Agrin Fragment (CAF) concentrations among mobility limited older adults

Author
item Bondoc, Irina
item Cochrane, Shannon
item Church, Timothy
item Dahinden, Pius
item Hettwer, Stefan
item Hsu, Fang-chi
item Stafford, Randall
item Pahor, Marco
item Buford, Thomas
item Reid, Kieran
item Fielding, Roger

Submitted to: Journal of Nutrition Health and Aging
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/14/2015
Publication Date: 11/1/2015
Citation: Bondoc, I., Cochrane, S., Church, T., Dahinden, P., Hettwer, S., Hsu, F., Stafford, R., Pahor, M., Buford, T.W., Reid, K., Fielding, R.A. 2015. Effects of a one year physical activity program on serum C Terminal Agrin Fragment (CAF) concentrations among mobility limited older adults. Journal of Nutrition Health and Aging. 19(9):922-927. doi: 10.1007/s12603-015-0474-3.

Interpretive Summary: C terminal Agrin Fragment (CAF) has been proposed as a potential measure in the blood that predicts changes in physical function among older adults. We sought to determine the effect of a one year PA intervention on changes in CAF concentrations and to evaluate baseline and longitudinal associations between CAF concentrations and indices of physical function. The present study shows that a one year structured PA program did not reduce serum CAF levels among mobility limited older adults. However, further study is needed to definitively determine the utility of CAF as a biomarker of physical function.

Technical Abstract: OBJECTIVES: C terminal Agrin Fragment (CAF) has been proposed as a potential circulating biomarker for predicting changes in physical function among older adults. To determine the effect of a one year PA intervention on changes in CAF concentrations and to evaluate baseline and longitudinal associations between CAF concentrations and indices of physical function. DESIGN: Ancillary study to the Lifestyle Interventions and Independence for Elders Pilot (LIFE P), a multi site randomized clinical trial designed to evaluate the effects of chronic exercise on the physical function of older adults at risk for mobility disability. SETTING: Four academic research centers within the U.S. PARTICIPANTS: Three hundred thirty three older adults aged 70 to 89 with mild to moderate impairments in physical function. INTERVENTION: A 12 month intervention of either structured physical activity (PA) or health education promoting successful aging (SA). MEASUREMENTS: Serum CAF concentrations and objectives measures of physical function i.e. gait speed and performance on the Short Physical Performance Battery (SPPB). RESULTS: The group*time interaction was not significant for serum CAF concentrations (p=0.265), indicating that the PA intervention did not significantly reduce serum CAF levels compared to SA. Baseline gait speed was significantly correlated with baseline CAF level (r = 0.151, p= 0.006), however the association between CAF and SPPB was not significant. Additionally, neither baseline nor the change in CAF concentrations strongly predicted the change in either performance measure following the PA intervention. CONCLUSION: In summary, the present study shows that a one year structured PA program did not reduce serum CAF levels among mobility limited older adults. However, further study is needed to definitively determine the utility of CAF as a biomarker of physical function.

Last Modified: 10/19/2017
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