Physical activity and changes in white matter hyperintensities over three years

OBJECTIVES: Since physical activity (PA) has demonstrated benefits for cardiovascular health, it is possible to hypothesize that higher or increasing PA slows the progression of white matter hyperintensities (WMH). We investigated the association between PA and the progression of WMH in non-demented older adults with memory complaints. DESIGN: We included 152 participants (mean age 74.7±3.8 years; 63.8% women) in the analyses, in whom information on self-reported PA and MRI was available at both baseline and 3-year follow-up. From the PA questionnaire, the baseline metabolic equivalent of task (MET-minute/week) and changes in MET-minute/week over three years were separately calculated for overall, leisure-time, and non-leisure time PA. WMH volume at baseline and 3-year follow-up was obtained by using an automated segmentation algorithm. RESULTS: Mixed-effect linear regression models showed that none of the baseline PA variables was associated with progression of WMH over time. People who had decreased their PA levels over three years tended to show greater progression of WMH compared with those who had maintained PA levels of ≥1200 MET-min/week (roughly equivalent to ≥300 minutes of brisk walking) in the unadjusted model (β±SE=4.85±2.42, p=0.045); however, this association was no longer significant after adjustment for confounders (β±SE =3.63±2.18, p=0.096). CONCLUSIONS: We did not find any significant association between PA and WMH in non-demented older adults with memory complaints. However, decrease over time in PA levels tended to be associated with progression of WMH. A larger longitudinal study with data on PA assessed using objective measures would provide important information in this field.