Physical activity in vascular cognitive impairment: Systematic review with meta-analysis.

BACKGROUND: Vascular cognitive impairment (VCI) is the second most common cause of cognitive impairment worldwide and includes a spectrum from vascular cognitive impairment no dementia (VCIND) to vascular dementia (VaD). There is no specific pharmacological treatment approved for VCI. Physical activity has been indicated to be a promising preventive measure for cognition, with direct as indirectly benefits, while improving several modifiable vascular risk factors, so potentially effective when considering VCI. Our aim was to conduct a systematic review with a meta-analysis approaching the potential preventive role of physical activity on VCI. METHODS: A systematic search was conducted in 7 databases. A total of 6786 studies were screened and assessed for eligibility, culminating in the inclusion of 9 observational prospective studies assessing physical activity impact irrespectively the type for quality assessment and qualitative and quantitative synthesis. Quantitative synthesis was performed using the reported adjusted HRs. Physical activity was handled as a dichotomous variable, with two groups created (high versus low physical activity). Subgroup analyses were done for risk of bias, VaD and length of follow-up. RESULTS: There was considerable methodological heterogeneity across studies. Only three studies reported significant associations. The overall effect was statistically significant (HR 0.68, 95%CI 0.54-0.86, I2 6.8%), with higher levels of physical activity associated with a smaller risk of VCI overtime, particularly VaD. CONCLUSIONS: These findings suggest that physical activity is a potential preventive factor for vascular dementia. Insufficient data is available on VCIND. Randomized studies are desired to confirm these results.