|Fitzgerald, Jodi - University Of Florida|
|Johnson, Lindsey - University Of Florida|
|Ambrosius, Walter - Wake Forest University|
|Anton, Stephen - University Of Florida|
|Dodson, John - New York University|
|Marsh, Anthony - Wake Forest University|
|Mcdermott, Mary - Northwestern University|
|Nocera, Joe - Emory University|
|Tudor-locke, Catrine - University Of Massachusetts|
|White, Daniel - University Of Delaware|
|Yank, Veronica - Stanford University|
|Pahor, Marco - University Of Florida|
|Manini, Todd - University Of Florida|
|Buford, Thomas - University Of Florida|
Submitted to: Journal of the American Heart Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2014
Publication Date: 2/18/2015
Citation: Fitzgerald, J.D., Johnson, L., Ambrosius, W.T., Anton, S.D., Dodson, J.A., Marsh, A.P., McDermott, M.M., Nocera, J.R., Tudor-Locke, C., White, D.K., Yank, V., Pahor, M., Manini, T., Buford, T. 2015. Association of objectively measured physical activity with cardiovascular risk in mobility-limited older adults. Journal of the American Heart Association. 4:e001288. https://doi.org/10.1161/JAHA.114.001288.
Interpretive Summary: Data are limited regarding the effects of habitual physical activity and sedentary (sitting) behavior on cardiovascular risk in older adults with mobility limitations. This study examined the baseline and cross-sectional association between cardiovascular risk and physical activity among participants in the Lifestyle Interventions and Independence for Elders (LIFE) study. The relationship between physical activity measures and predicted 10-year Coronary Heart Disease (CHD) risk was examined statistically and adjusted for prior cardiovascular disease history. A total of 1,170 participants who were roughly 80 years old were studied. We found that daily time spent being sedentary (sitting) is positively associated with predicted 10-year CHD risk among mobility-limited older adults. Duration of daily physical activity is also inversely associated with CHD risk score in this population.
Technical Abstract: Background: Data are sparse regarding the impacts of habitual physical activity (PA) and sedentary behavior on cardiovascular (CV) risk in older adults with mobility limitations. Methods and Results: This study examined the baseline, cross-sectional association between CV risk and objectively measured PA among participants in the Lifestyle Interventions and Independence for Elders (LIFE) study. The relationship between accelerometry measures and predicted 10-year Hard Coronary Heart Disease (HCHD) risk was modeled by using linear regression, stratified according to CVD history. Participants (n=1170, 79 +/- 5 years) spent 642 +/- 111 min/day in sedentary behavior (ie, <100 accelerometry counts/min). They also spent 138 +/- 43 min/day engaging in PA registering 100 to 499 accelerometry counts/min and 54 +/- 37 min/day engaging in PA >/= 500 counts/min. Each minute per day spent being sedentary was associated with increased HCHD risk among both those with (0.04%, 95% CI 0.02% to 0.05%) and those without (0.03%, 95% CI 0.02% to 0.03%) CVD. The time spent engaging in activities 100 to 499 as well as >/=500 counts/min was associated with decreased risk among both those with and without CVD (P<0.05). The mean number of counts per minute of daily PA was not significantly associated with HCHD risk in any model (P>0.05). However, a significant interaction was observed between sex and count frequency (P=0.036) for those without CVD, as counts per minute was related to HCHD risk in women (beta= -0.94, -1.48 to -0.41; P<0.001) but not in men (beta= -0.14, -0.59 to 0.88; P=0.704). Conclusions: Daily time spent being sedentary is positively associated with predicted 10-year HCHD risk among mobility-limited older adults. Duration, but not intensity (ie, mean counts/min), of daily PA is inversely associated with HCHD risk score in this population-- although the association for intensity may be sex specific among persons without CVD.