Arterial stiffness as a cause of cognitive decline and dementia: a systematic review and meta-analysis.

BACKGROUND

Although arterial stiffness has recently been confirmed as a predictor of cardiovascular disease, the association between arterial stiffness and cognitive decline is less clear.

AIM

We performed a systematic review and meta-analysis to examine the evidence for large artery stiffness as a cause of cognitive decline and dementia.

METHOD

Electronic databases were systematically searched until September 2011 for studies reporting on the longitudinal relationship between any validated measure of large artery stiffness and cognitive decline or dementia. Meta-analysis was performed on four studies investigating the association between aortic pulse wave velocity and a decline in Mini-Mental State Examination scores.

RESULTS

Six relevant longitudinal studies were located, conducted over an average of 5 years follow up. Arterial stiffness was predictive of cognitive decline in five/six studies. In meta-analysis, higher aortic stiffness predicted lower Mini-Mental State Examination scores within the sample (β=-0.03, 95% confidence interval (CI): -0.06 to 0.01, n= 3947), although studies were not all homogeneous, and statistical heterogeneity was present (I(2) = 71.9%, P= 0.01). Removal of one study with a relatively younger cohort and lower median aortic stiffness found higher aortic stiffness to significantly predict cognitive decline (β=-0.04, 95% CI: -0.07 to -0.01, n= 3687) without evidence of heterogeneity (I(2) = 9.5%, P= 0.33). There was little research investigating the effects of aortic stiffness on the development of dementia.

CONCLUSION

Aortic stiffness was found to predict cognitive decline in both qualitative review and quantitative analysis.