Only one third of older
breast cancer survivors (BCS) meet national physical activity (PA)
guidelines. Theories of self-regulation
and research with older adults suggest that executive function (EF) plays an
important role in PA, yet the impact of lower EF on older survivors’ PA is
unknown. My project addressed this gap
using secondary data from the Thinking and Living with Cancer (TLC) cohort
study, which examined cognitive function among older BCS pre-treatment,
followed every 12 months, and contemporaneously assessed matched controls. My first aim was to test two hypotheses
regarding EF change and PA and determine if these relationships differ between
BCS and controls. My hypotheses were: 1)
EF decline from baseline to 12 months will predict lower PA at 24 months, and
2) lower PA at 12 months will predict EF decline from 12 to 24 months. My second aim was to explore whether the
effects of EF change on PA in BCS differed based on risk factors for
accelerated cognitive decline (i.e., older age, more advanced cancer stage,
comorbidity, and <i>APOE</i> ε4 genotype).
The TLC study measured EF with neuropsychological tests and PA with the
International Physical Activity Questionnaire-Short Form. For aims 1 and 2, I used multiple regression
with multiple imputation. Primary
results showed no significant effect of EF change from baseline to 12 months on
PA at 24 months (β=-0.01, p=0.88) and no significant group (BCS vs. controls)
by EF interaction (β=-0.05, p=0.33).
Separate models in BCS and controls showed similar findings. In the entire sample, PA at 12 months
significantly predicted EF change from 12 to 24 months (β=0.17, p=0.01), but
there was no significant group by PA interaction (β=-0.06, p=0.54). Separate analyses by group found a
significant effect of PA for controls (β=0.07, p=0.02), but not for BCS
(β=0.05, p=0.27). Regarding the second
aim, there were no significant interactions between EF change and the proposed
risk factors on PA. Findings were
largely inconsistent with theory and prior research. Continued research in this area will inform
future exercise interventions to improve physical and cognitive health for the
growing population of older cancer survivors.
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/10312799 |
| Date | 15 November 2019 |
| Creators | Danielle Bowman Tometich (7861526) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/A_PROSPECTIVE_EXAMINATION_OF_CHANGE_IN_EXECUTIVE_FUNCTION_AND_PHYSICAL_ACTIVITY_IN_OLDER_BREAST_CANCER_SURVIVORS/10312799 |
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