The relationship between physical activity and subjective cognitive decline: Evidence from the behavioral risk factor surveillance system (BRFSS)

Background: Studies have shown that subjective cognitive decline (SCD) is a major risk factor for mild cognitive impairment or even dementia, but the relationship between physical activity (PA) and SCD is still unclear. The goal of current study is to address how various physical activities relate to SCD.Methods: 216,593 adults from the Behavioral Risk Factor Surveillance System (BRFSS) were included in this study. We measured SCD and PA with participants' self-report. With the unconditional logistic regression model, the association between PA and SCD was investigated. We used a four-way decomposition method to explore the mediation roles of depression between PA and SCD. The nearest matching method of propensity score and multinomial propensity score were used to reduce the effects of confounding factors.Results: Compared with those inactive, the weighted adjusted odds ratios (AORs) of SCD among those who were physically active were <1 (p < 0.005), regardless of the type of PA. The top three PA in weighted AORs were: running (AOR: 0.51, 95 % CI: 0.50-0.52), aerobics exercise (AOR: 0.55, 95 % CI: 0.53-0.56), and weightlifting (AOR: 0.60, 95 % CI: 0.59-0.62). The dose-response relationship between PA and SCD was found. Participants who engaged in PA for 241-300 min per week (AOR: 0.61, 95 % CI: 0.59-0.62) or exercised metabolic equivalent of 801-1000 per week (AOR: 0.62, 95 % CI: 0.62-0.65) had the lowest risk of SCD.Conclusions: Regardless of the specific PA types, engaging in PA is associated with a reduced risk of having SCD, and people who engage in running had the lowest risk of SCD. There was a dose-response relationship between PA and SCD, and PA-based interventions should be developed accordingly to prevent cognitive deterioration in older age.