Impact of Ambulatory Blood Pressure Variability on Cerebral Small Vessel Disease Progression and Cognitive Decline in Community-Based Elderly Japanese Yoshitaka Yamaguchi,1 Manabu Wada,1 Hidenori Sato,1 Hikaru Nagasawa,1 Shingo Koyama,1 Yoshimi Takahashi,1 Toru Kawanami,1 and Takeo Kato1

Microvascular ischemia in the brain manifests as formation of white matter lesions (WMLs) and lacunae that ultimately result in gait disturbance, cognitive impairment, and dementia.1,2 Most of the changes are caused by cerebral small vessel disease (SVD), but the pathogenesis of cerebral SVD is incompletely understood.3 There is extensive literature describing the relationships between SVD and cerebrovascular risk factors such as hypertension, diabetes, and chronic kidney disease.4,5 Hypertension is known to be a major risk factor that contributes to the acceleration of brain damage. Recent evidence indicates that 24-hour ambulatory blood pressure monitoring (ABPM) is more useful for evaluating cardiovascular risk than casual blood pressure (BP) measurement.6–9 BP variability (BPV) over the course of many hours has been well documented by 24-hour ABPM, and previous studies reported that ambulatory blood pressure (ABP) variability predicted cardiovascular risk in hypertensive patients.6–9 However, the impact of ABP variability on SVD progression10 and cognitive decline in elderly individuals has not been well investigated in community-based studies. Because cognitive function and cerebral SVD are associated with age,2 this study focused on evaluation of subjects aged 70–72 years to minimize the impact of age on the parameters studied. This longitudinal study examined the relationships between BPV evaluated by 24-hour ABPM and cerebral SVD and global cognitive function in community-dwelling elderly Japanese individuals. Brain magnetic resonance imaging (MRI) and cognitive function testing were performed at baseline and repeated 4 years later to determine whether SVD progression and cognitive decline were related to ABP variability. We also investigated whether these relationships were independent of conventional risk factors and carotid artery atherosclerosis. Impact of Ambulatory Blood Pressure Variability on Cerebral Small Vessel Disease Progression and Cognitive Decline in Community-Based Elderly Japanese