White matter hyperintensities and the progression of frailty - the Tasmanian Study of Cognition and Gait

Background: The contribution of cerebral small vessel disease (cSVD) to the pathogenesis of frailty remains uncertain. We aimed to examine the associations between cSVD with progression of frailty in a population-based study of older people.

Methods: People aged between 60 and 85 years were randomly selected form the electoral roll to participate in the Tasmanian Study on Cognition and Gait. Participants underwent self-reported questionnaires, objective gait, cognitive and sensorimotor testing over three phases ranging between 2005 and 2012. These data were used to calculate a 41 item frailty index at three time points. Baseline brain magnetic resonance imaging was performed on all participants to measure cSVD. Generalized mixed models were used to examine associations between baseline cSVD and progression of frailty, adjusted for confounders of age, sex, level of education and total intracranial volume.

Results: At baseline (n=388) mean age was 72 years (SD 7.0), 44% were female and the median frailty index score was 0.20 (IQR 0.12, 0.27). In fully adjusted models higher burden of baseline WMH was associated with frailty progression over 4.4 years (β 0.03 95%CI 0.01,0.05; p=0.004) independent of other SVD markers. Neither baseline infarcts (p =0.23), nor microbleeds at baseline (p=0.65) were associated with progression of frailty.

Conclusion: We provide evidence for an association between baseline white matter hyperintensities and progression of frailty. Our findings add to a growing body of literature suggesting WMH is a marker for frailty.