Leisure-time physical activity, cardiorespiratory fitness, and cognitive decline in middle-aged and older adults - The ELSA-Brasil study

Objectives

Dementia is a fast-growing public health problem. This study examined the association of physical activity and estimated cardiorespiratory fitness (eCRF) with the risk of cognitive impairment.

Study design

Multicentric, prospective cohort study.

Methods

We analyzed 10,121 participants of the ELSA-Brasil study. We assessed leisure-time physical activity using the long version of the IPAQ questionnaire and defined moderate-to-vigorous physical activity (MVPA) per week. We applied a non-exercise prediction equation to estimate eCRF and classified participants as unfit (lowest tertile) and fit. Leisure-time MVPA and eCRF were measured at baseline and follow-up. Incident cognitive impairment was based on memory, language, and executive function assessed at baseline and follow-up.

Results

During a median of 8.1 (7.8–8.5) years of follow-up, we identified 396 (3.9 %) incident cases of cognitive impairment. There was an inverse, non-linear association between the incidence of cognitive impairment and both leisure time MVPA and eCRF. Low eCRF (IRR: 1.29; 95%CI: 1.02, 1.64) and low MVPA (IRR: 1.40; 1.09, 1.82) were independently associated with an increased incidence. Increasing 1 MET in eCRF from baseline to follow-up visit was associated with a lower incidence of cognitive impairment (IRR: 0.80; 95%CI: 0.71, 0.91), while a decrease of 13.7 min per day in leisure time MVPA is associated with an increased incidence (IRR: 1.16; 95%CI: 1.01, 1.33) of cognitive impairment. These associations remained statistically significant in adults under 65 but not in older adults.

Conclusion

Low eCRF and leisure time MVPA are strong and independent predictors of incident cognitive impairment especially in middle-aged adults.