Objectively-measured Physical Activity And White Matter Hyperintensity With Physical Performance In Older Adults:MIND-China Study

Background:Brain white matter hyperintensity(WMH)volume is highly prevalent in older adults and is associated with physical performance decline.Physical activity(PA)is considered a good lifestyle and has a variety of benefits.In the current study,we aim to explore the association between WMH burden and physical performance as well as the role of physical activity(PA)among older adults.Methods:This population-based cross-sectional study included 959 participants(age≥60 years;59.6%women)who undertook brain magnetic resonance imaging(MRI)with valid physical performance and objectively-measured PA data.Physical performance was assessed by the short physical performance battery(SPPB)test,a hierarchical test of standing balance tests,chair stands tests,and walking tests.Daily time spent on light-intensity physical activity(LPA),moderate-to-vigorous-intensity physical activity(MVPA)and vigorous-intensity physical activity(VPA)were quantified using accelerometers.Data were analyzed using the general linear regression models.Results:The global WMH volume was associated with multi-adjusted β-coefficient(95%confidence interval)of-0.020(-0.032,-0.008)for SPPB summary scores,-0.004(-0.009,0.001)for standing balance scores,-0.007(-0.014,0.000)for chair stands scores and-0.009(0.013,-0.005)for walk test scores.In addition,both higher periventricular and deep WMH volumes were associated with lower walk test scores,meanwhile higher periventricular WMH volumes,but not deep WMH volumes,were significantly associated with lower SPPB summary scores.Finally,MVPA modulated the effect of WMH burden on walk performance(P for interaction=0.016),such that increased brain WMH volume was associated with walk performance only when MVPA time<0.24 hour/day.Conclusion:Global WMH burden,especially periventricular WMH,was significantly associated with poor physical performance among older adults.Individuals with high-level MVPA were less susceptible to the detrimental effect of the global WMH burden on walk performance.