Relationship Between Physical Activity and Stem Cells in Older Adults

Increased numbers of circulating stem cells and physical activity are both associated with
improved health in older persons. This pilot study is the initial step in developing a
collaborative, translational research project investigating whether physical activity may in
part exert a positive influence on aging via the mobilization of stem cells. The specific
aim of this pilot project is to collect preliminary data to explore the relationship between
physical activity and stem cell populations found in the blood and to determine the variance
in the number of circulating stem cells. We hypothesize that stem cell decrease with age,
but that persons who are more physically active will have a higher number of stem cells in
the blood. A maximum of 40 persons will be recruited to participate. Persons are eligible
to participate if they are age 60 or older, haven't been hospitalized recently, do not have
an immunologic or blood disease, do not have an infection, and are not undergoing
chemotherapy. Subjects will have 2 visits to the UNMC Clinical Research Center (CRC). The
first assessment will include an evaluation of health, physical activity and lifestyle via
questionnaires. Height, weight and abdominal girth will be measured, and blood will be
drawn for immune and stem cell assessment. Subjects will be given a pedometer and
accelerometer to wear daily for 7 days. Subjects will return to the CRC for a second visit
at which the pedometer and accelerometer will be returned and blood will be drawn. Stem
cell and immune assays will be repeated to evaluate the variability of these measures over
time. The correlation between stem cell numbers and physical activity will be analyzed.
The data will be used to perform sample size calculations for the development of future
studies.