Associations between physical activity and cognitive functioning among middle-aged and older adults

To describe aerobic physical activity among middle-aged and older adults by their selfreported cognitive decline and their receipt of informal care for declines in cognitive functioning and most common type of physical activity.

Cross-sectional study using data from the 2011 Behavioral Risk Factor Surveillance System.

Landline and cellular telephone survey.

93,082 respondents aged 45 years and older from 21 US states in 2011.

Subjective cognitive decline (SCD) was defined as experiencing confusion or memory loss that was happening more often or getting worse during the past 12 months. Regular care was defined as always, usually, or sometimes receiving care from family or friends because of SCD. Using the 2008 Physical Activity Guidelines for Americans, respondents were classified as being inactive, insufficiently active, or sufficiently active based on their reported aerobic exercise. We calculated weighted proportions and used chi-square tests for differences across categories by SCD status and receipt of care. We estimated the prevalence ratio (PR) for being inactive, insufficiently active, and sufficiently active using separate log-binomial regression models, adjusting for covariates.

12.3% of respondents reported SCD and 23.1% of those with SCD received regular care. 29.6% (95%CI: 28.9-30.4) of respondents without SCD were inactive compared to 37.1% (95%CI: 34.7-39.5) of those with SCD who did not receive regular care and 50.2% (95%CI: 45.2-55.1) of those with SCD who received regular care. 52.4% (95%CI: 51.6-53.2) of respondents without SCD were sufficiently active compared to 46.4% (95%CI: 43.8-49.0) of respondents with SCD and received no regular care and 30.6% (95%CI: 26.1-35.6) of respondents with SCD who received regular care. After adjusting for demographic and health status differences, people receiving regular care for SCD had a significantly lower prevalence of meeting aerobic guidelines compared to people without SCD (PR=0.80, 95%CI: 0.69-0.93, p=0.005). The most prevalent physical activity was walking for adults aged ≥ 45 years old (41-52%) regardless of SCD status or receipt of care.

Overall, the prevalence of inactivity was high, especially among people with SCD. These findings suggest a need to increase activity among middle-aged and older adults, particularly those with SCD who receive care. Examining ways to increase walking, potentially by involving informal caregivers, could be a promising way for people with SCD to reduce inactivity and gain the health benefits associated with meeting physical activity guidelines.