Role of objectively measured physical activity and sedentary behavior on successful aging: population-based longitudinal study in older adults

• Applicants: Professor Dr. Michael Denkinger; Professor Dr. Dietrich Rothenbacher
• Subject Area: Biogerontology and Geriatric Medicine
• Term: from 2016 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 317230302

Physical activity or mobility as a main factor of general activity is a major target in the International classification of Functioning, Disability and Health (ICF) framework to maintain or improve social participation and independent living. Strong evidence exists that physically active subjects have higher levels of physical fitness, better quality of life, and a lower risk for a variety of chronic diseases such as cardiovascular diseases, diabetes, cancer and that it is closely linked to attenuating cognitive and functional decline over time. However, data from older adults, which are at the highest risk for most of the diseases relevant in this context and in whom physical activity declines most, are still sparse. Also, longitudinal data of physical activity and sedentary behaviour trajectories in older persons based on repeated measurements are lacking. Furthermore, most available large cohort studies including older adults have estimated physical activity using retrospective questionnaires. Especially studies with repeated measurements and with longer follow-up which allow performing sensitivity analysis would help to clarify the question of possible reverse causation. The Activity Function in the Elderly in Ulm (ActiFE Ulm) study is a large cohort study in older adults with a sufficiently long follow up that included extensive accelerometer-based data on physical activity and sedentary behavior from the beginning. ActiFE Ulm is a population-based study including n=1506 older people aged 65+ years located in Southern Germany which had already been seen during an additional follow-up. During this first follow-up between August 2012 and November 2013 n=834 participants were reassessed including again a one week sensor measurement of physical activity, blood samples as well as functional, cognitive and social assessments. The objective of this proposed prospective cohort study is now to describe trajectories of physical activity and sedentary behavior in older adults during a seven year follow-up period. The assessment of physical activity and sedentary behavior will be again based on an objective measurement (accelerometer-based wearable motion detectors worn over 7 days). The prognostic association of baseline physical activity and sedentary behavior with various measures of functional status, with falls and fractures, with other morbidity (i.e. cognitive decline), with mortality rates and with specific biomarkers will be analyzed. The study will further allow identifying determinants as well as consequences of changes in physical activity and sedentary behavior patterns and trajectories. A better understanding of the health-related consequences of these patterns will enable identifying potential targets of intervention and allow a longitudinal validation of biomarkers for sedentary behavior and activity. We are confident, that our results will close existing knowledge gaps and will have important translational aspects.

• DFG Programme: Research Grants